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Title: How it Works

Author: Archibald Williams

Release date: April 10, 2009 [eBook #28553]
                Most recently updated: January 4, 2021

Language: English

Credits: Produced by Steven Gibbs, Greg Bergquist and the Online
        Distributed Proofreading Team at https://www.pgdp.net


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Produced by Steven Gibbs, Greg Bergquist and the Online
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Transcriber's Note

The punctuation and spelling from the original text have been faithfully
preserved. Only obvious typographical errors have been corrected.
Subscripts are represented as X_1. Superscripts are represented by X^1.


HOW IT WORKS




AUTHOR'S NOTE.


I beg to thank the following gentlemen and firms for the help they have
given me in connection with the letterpress and illustrations of "How It
Works"--

Messrs. F.J.C. Pole and M.G. Tweedie (for revision of MS.); W. Lineham;
J.F. Kendall; E. Edser; A.D. Helps; J. Limb; The Edison Bell Phonograph
Co.; Messrs. Holmes and Co.; The Pelton Wheel Co.; Messrs. Babcock and
Wilcox; Messrs. Siebe, Gorman, and Co.; Messrs. Negretti and Zambra;
Messrs. Chubb; The Yale Lock Co.; The Micrometer Engineering Co.;
Messrs. Marshall and Sons; The Maignen Filter Co.; Messrs. Broadwood and
Co.

[Illustration: ON THE FOOTPLATE OF A LOCOMOTIVE.]

  How It Works

  Dealing in Simple Language with Steam, Electricity,
  Light, Heat, Sound, Hydraulics, Optics, etc.
  and with their applications to Apparatus
  in Common Use

  By
  ARCHIBALD WILLIAMS

  Author of "The Romance of Modern Invention,"
  "The Romance of Mining," etc., etc.

  THOMAS NELSON AND SONS

  London, Edinburgh, Dublin, and New York




PREFACE.


How does it work? This question has been put to me so often by persons
young and old that I have at last decided to answer it in such a manner
that a much larger public than that with which I have personal
acquaintance may be able to satisfy themselves as to the principles
underlying many of the mechanisms met with in everyday life.

In order to include steam, electricity, optics, hydraulics, thermics,
light, and a variety of detached mechanisms which cannot be classified
under any one of these heads, within the compass of about 450 pages, I
have to be content with a comparatively brief treatment of each subject.
This brevity has in turn compelled me to deal with principles rather
than with detailed descriptions of individual devices--though in several
cases recognized types are examined. The reader will look in vain for
accounts of the Yerkes telescope, of the latest thing in motor cars, and
of the largest locomotive. But he will be put in the way of
understanding the essential nature of _all_ telescopes, motors, and
steam-engines so far as they are at present developed, which I think may
be of greater ultimate profit to the uninitiated.

While careful to avoid puzzling the reader by the use of mysterious
phraseology I consider that the parts of a machine should be given their
technical names wherever possible. To prevent misconception, many of
the diagrams accompanying the letterpress have words as well as letters
written on them. This course also obviates the wearisome reference from
text to diagram necessitated by the use of solitary letters or figures.

I may add, with regard to the diagrams of this book, that they are
purposely somewhat unconventional, not being drawn to scale nor
conforming to the canons of professional draughtsmanship. Where
advisable, a part of a machine has been exaggerated to show its details.
As a rule solid black has been preferred to fine shading in sectional
drawings, and all unnecessary lines are omitted. I would here
acknowledge my indebtedness to my draughtsman, Mr. Frank Hodgson, for
his care and industry in preparing the two hundred or more diagrams for
which he was responsible.

Four organs of the body--the eye, the ear, the larynx, and the
heart--are noticed in appropriate places. The eye is compared with the
camera, the larynx with a reed pipe, the heart with a pump, while the
ear fitly opens the chapter on acoustics. The reader who is unacquainted
with physiology will thus be enabled to appreciate the better these
marvellous devices, far more marvellous, by reason of their absolutely
automatic action, than any creation of human hands.

  A.W.

UPLANDS, STOKE POGES, BUCKS.




CONTENTS.


Chapter I.--THE STEAM-ENGINE.

What is steam?--The mechanical energy of steam--The boiler--The
circulation of water in a boiler--The enclosed furnace--The
multitubular boiler--Fire-tube boilers--Other types of boilers--Aids
to combustion--Boiler fittings--The safety-valve--The
water-gauge--The steam-gauge--The water supply to a
boiler      13


Chapter II.--THE CONVERSION OF HEAT ENERGY
INTO MECHANICAL MOTION.

Reciprocating engines--Double-cylinder engines--The function of
the fly-wheel--The cylinder--The slide-valve--The eccentric--"Lap"
of the valve: expansion of steam--How the cut-off is
managed--Limit of expansive working--Compound engines--Arrangement
of expansion engines--Compound locomotives--Reversing
gears--"Linking-up"--Piston-valves--Speed governors--Marine-speed
governors--The condenser      44


Chapter III.--THE STEAM TURBINE.

How a turbine works--The De Laval turbine--The Parsons turbine--Description
of the Parsons turbine--The expansive action of
steam in a Parsons turbine--Balancing the thrust--Advantages
of the marine turbine      74


Chapter IV.--THE INTERNAL-COMBUSTION ENGINE.

The meaning of the term--Action of the internal-combustion engine--The
motor car--The starting-handle--The engine--The carburetter--Ignition
of the charge--Advancing the spark--Governing
the engine--The clutch--The gear-box--The compensating
gear--The silencer--The brakes--Speed of cars      87


Chapter V.--ELECTRICAL APPARATUS.

What is electricity?--Forms of electricity--Magnetism--The permanent
magnet--Lines of force--Electro-magnets--The electric
bell--The induction coil--The condenser--Transformation of
current--Uses of the induction coil      112


Chapter VI.--THE ELECTRIC TELEGRAPH.

Needle instruments--Influence of current on the magnetic needle--Method
of reversing the current--Sounding instruments--Telegraphic
relays--Recording telegraphs--High-speed telegraphy      127


Chapter VII.--WIRELESS TELEGRAPHY.

The transmitting apparatus--The receiving apparatus--Syntonic
transmission--The advance of wireless telegraphy      137


Chapter VIII.--THE TELEPHONE.

The Bell telephone--The Edison transmitter--The granular carbon
transmitter--General arrangement of a telephone circuit--Double-line
circuits--Telephone exchanges--Submarine telephony      147


Chapter IX.--DYNAMOS AND ELECTRIC MOTORS.

A simple dynamo--Continuous-current dynamos--Multipolar
dynamos--Exciting the field magnets--Alternating current dynamos--The
transmission of power--The electric motor--Electric lighting--The
incandescent lamp--Arc lamps--"Series" and "parallel" arrangement of
lamps--Current for electric lamps--Electroplating      159


Chapter X.--RAILWAY BRAKES.

The Vacuum Automatic brake--The Westinghouse air-brake      187


Chapter XI.--RAILWAY SIGNALLING.

The block system--Position of signals--Interlocking the signals--Locking
gear--Points--Points and signals in combination--Working
the block system--Series of signalling operations--Single
line signals--The train staff--Train staff and ticket--Electric
train staff system--Interlocking--Signalling operations--Power
signalling--Pneumatic signalling--Automatic
signalling      200


Chapter XII.--OPTICS.

Lenses--The image cast by a convex lens--Focus--Relative position
of object and lens--Correction of lenses for colour--Spherical
aberration--Distortion of image--The human eye--The use of
spectacles--The blind spot      230


Chapter XIII.--THE MICROSCOPE, THE TELESCOPE,
AND THE MAGIC-LANTERN.

The simple microscope--Use of the simple microscope in the telescope--The
terrestrial telescope--The Galilean telescope--The
prismatic telescope--The reflecting telescope--The parabolic
mirror--The compound microscope--The magic-lantern--The
bioscope--The plane mirror      253


Chapter XIV.--SOUND AND MUSICAL INSTRUMENTS.

Nature of sound--The ear--Musical instruments--The vibration of
strings--The sounding-board and the frame of a piano--The
strings--The striking mechanism--The quality of a note      270


Chapter XV.--WIND INSTRUMENTS.

Longitudinal vibration--Columns of air--Resonance of columns of
air--Length and tone--The open pipe--The overtones of an
open pipe--Where overtones are used--The arrangement of the
pipes and pedals--Separate sound-boards--Varieties of stops--Tuning
pipes and reeds--The bellows--Electric and pneumatic
actions--The largest organ in the world--Human reeds      287


Chapter XVI.--TALKING-MACHINES.

The phonograph--The recorder--The reproducer--The gramophone--The
making of records--Cylinder records--Gramophone
records      310


Chapter XVII.--WHY THE WIND BLOWS.

Why the wind blows--Land and sea breezes--Light air and moisture--The
barometer--The column barometer--The wheel barometer--A
very simple barometer--The aneroid barometer--Barometers
and weather--The diving-bell--The diving-dress--Air-pumps--Pneumatic
tyres--The air-gun--The self-closing door-stop--The
action of wind on oblique surfaces--The balloon--The
flying-machine      322


Chapter XVIII.--HYDRAULIC MACHINERY.

The siphon--The bucket pump--The force-pump--The most marvellous
pump--The blood channels--The course of the blood--The
hydraulic press--Household water-supply fittings--The
ball-cock--The water-meter--Water-supply systems--The household
filter--Gas traps--Water engines--The cream separator--The
"hydro"      350


Chapter XIX.--HEATING AND LIGHTING.

The hot-water supply--The tank system--The cylinder system--How
a lamp works--Gas and gasworks--Automatic stoking--A
gas governor--The gas meter--Incandescent gas lighting      386


Chapter XX.--VARIOUS MECHANISMS.

CLOCKS AND WATCHES:--A short history of timepieces--The construction
of timepieces--The driving power--The escapement--Compensating
pendulums--The spring balance--The cylinder
escapement--The lever escapement--Compensated balance-wheels--Keyless
winding mechanism for watches--The hour hand
train. LOCKS:--The Chubb lock--The Yale lock. THE CYCLE:--The
gearing of a cycle--The free wheel--The change-speed gear.
AGRICULTURAL MACHINES:--The threshing-machine--Mowing-machines.
SOME NATURAL PHENOMENA:--Why sun-heat varies
in intensity--The tides--Why high tide varies daily      410




HOW IT WORKS.




Chapter I.

THE STEAM-ENGINE.

     What is steam?--The mechanical energy of steam--The boiler--The
     circulation of water in a boiler--The enclosed furnace--The
     multitubular boiler--Fire-tube boilers--Other types of
     boilers--Aids to combustion--Boiler fittings--The safety-valve--The
     water-gauge--The steam-gauge--The water supply to a boiler.


WHAT IS STEAM?

If ice be heated above 32° Fahrenheit, its molecules lose their
cohesion, and move freely round one another--the ice is turned into
water. Heat water above 212° Fahrenheit, and the molecules exhibit a
violent mutual repulsion, and, like dormant bees revived by spring
sunshine, separate and dart to and fro. If confined in an air-tight
vessel, the molecules have their flights curtailed, and beat more and
more violently against their prison walls, so that every square inch of
the vessel is subjected to a rising pressure. We may compare the action
of the steam molecules to that of bullets fired from a machine-gun at a
plate mounted on a spring. The faster the bullets came, the greater
would be the continuous compression of the spring.


THE MECHANICAL ENERGY OF STEAM.

If steam is let into one end of a cylinder behind an air-tight but
freely-moving piston, it will bombard the walls of the cylinder and the
piston; and if the united push of the molecules on the one side of the
latter is greater than the resistance on the other side opposing its
motion, the piston must move. Having thus partly got their liberty, the
molecules become less active, and do not rush about so vigorously. The
pressure on the piston decreases as it moves. But if the piston were
driven back to its original position against the force of the steam, the
molecular activity--that is, pressure--would be restored. We are here
assuming that no heat has passed through the cylinder or piston and been
radiated into the air; for any loss of heat means loss of energy, since
heat _is_ energy.


THE BOILER.

The combustion of fuel in a furnace causes the walls of the furnace to
become _hot_, which means that the molecules of the substance forming
the walls are thrown into violent agitation. If the walls are what are
called "good conductors" of heat, they will transmit the agitation
through them to any surrounding substance. In the case of the ordinary
house stove this is the air, which itself is agitated, or grows warm. A
steam-boiler has the furnace walls surrounded by water, and its function
is to transmit molecular movement (heat, or energy) through the furnace
plates to the water until the point is reached when steam generates. At
atmospheric pressure--that is, if not confined in any way--steam would
fill 1,610 times the space which its molecules occupied in their watery
formation. If we seal up the boiler so that no escape is possible for
the steam molecules, their motion becomes more and more rapid, and
_pressure_ is developed by their beating on the walls of the boiler.
There is theoretically no limit to which the pressure may be raised,
provided that sufficient fuel-combustion energy is transmitted to the
vaporizing water.

To raise steam in large quantities we must employ a fuel which develops
great heat in proportion to its weight, is readily procured, and cheap.
Coal fulfils all these conditions. Of the 800 million tons mined
annually throughout the world, 400 million tons are burnt in the
furnaces of steam-boilers.

A good boiler must be--(1) Strong enough to withstand much higher
pressures than that at which it is worked; (2) so designed as to burn
its fuel to the greatest advantage.

Even in the best-designed boilers a large part of the combustion heat
passes through the chimney, while a further proportion is radiated from
the boiler. Professor John Perry[1] considers that this waste amounts,
under the best conditions at present obtainable, to eleven-twelfths of
the whole. We have to burn a shillingsworth of coal to capture the
energy stored in a pennyworth. Yet the steam-engine of to-day is three
or four times as efficient as the engine of fifty years ago. This is due
to radical improvements in the design of boilers and of the machinery
which converts the heat energy of steam into mechanical motion.


CIRCULATION OF WATER IN A BOILER.

If you place a pot filled with water on an open fire, and watch it when
it boils, you will notice that the water heaves up at the sides and
plunges down at the centre. This is due to the water being heated most
at the sides, and therefore being lightest there. The rising
steam-bubbles also carry it up. On reaching the surface, the bubbles
burst, the steam escapes, and the water loses some of its heat, and
rushes down again to take the place of steam-laden water rising.

[Illustration: FIG. 1.]

[Illustration: FIG. 2.]

If the fire is very fierce, steam-bubbles may rise from all points at
the bottom, and impede downward currents (Fig. 1). The pot then "boils
over."

Fig. 2 shows a method of preventing this trouble. We lower into our pot
a vessel of somewhat smaller diameter, with a hole in the bottom,
arranged in such a manner as to leave a space between it and the pot
all round. The upward currents are then separated entirely from the
downward, and the fire can be forced to a very much greater extent than
before without the water boiling over. This very simple arrangement is
the basis of many devices for producing free circulation of the water in
steam-boilers.

We can easily follow out the process of development. In Fig. 3 we see a
simple U-tube depending from a vessel of water. Heat is applied to the
left leg, and a steady circulation at once commences. In order to
increase the heating surface we can extend the heated leg into a long
incline (Fig. 4), beneath which three lamps instead of only one are
placed. The direction of the circulation is the same, but its rate is
increased.

[Illustration: FIG. 3.]

A further improvement results from increasing the number of tubes (Fig.
5), keeping them all on the slant, so that the heated water and steam
may rise freely.


THE ENCLOSED FURNACE.

[Illustration: FIG. 4.]

[Illustration: FIG. 5.]

Still, a lot of the heat gets away. In a steam-boiler the burning fuel
is enclosed either by fire-brick or a "water-jacket," forming part of
the boiler. A water-jacket signifies a double coating of metal plates
with a space between, which is filled with water (see Fig. 6). The fire
is now enclosed much as it is in a kitchen range. But our boiler must
not be so wasteful of the heat as is that useful household fixture. On
their way to the funnel the flames and hot gases should act on a very
large metal or other surface in contact with the water of the boiler, in
order to give up a due proportion of their heat.

[Illustration: FIG. 6.--Diagrammatic sketch of a locomotive type of
boiler. Water indicated by dotted lines. The arrows show the direction
taken by the air and hot gases from the air-door to the funnel.]


THE MULTITUBULAR BOILER.

[Illustration: FIG. 7.--The Babcock and Wilcox water-tube boiler. One
side of the brick seating has been removed to show the arrangement of
the water-tubes and furnace.]

To save room, boilers which have to make steam very quickly and at high
pressures are largely composed of pipes. Such boilers we call
multitubular. They are of two kinds--(1) _Water_-tube boilers; in which
the water circulates through tubes exposed to the furnace heat. The
Babcock and Wilcox boiler (Fig. 7) is typical of this variety. (2)
_Fire_-tube boilers; in which the hot gases pass through tubes
surrounded by water. The ordinary locomotive boiler (Fig. 6) illustrates
this form.

The Babcock and Wilcox boiler is widely used in mines, power stations,
and, in a modified form, on shipboard. It consists of two main
parts--(1) A drum, H, in the upper part of which the steam collects; (2)
a group of pipes arranged on the principle illustrated by Fig. 5. The
boiler is seated on a rectangular frame of fire-bricks. At one end is
the furnace door; at the other the exit to the chimney. From the furnace
F the flames and hot gases rise round the upper end of the sloping tubes
TT into the space A, where they play upon the under surface of H before
plunging downward again among the tubes into the space B. Here the
temperature is lower. The arrows indicate further journeys upwards into
the space C on the right of a fire-brick division, and past the down
tubes SS into D, whence the hot gases find an escape into the chimney
through the opening E. It will be noticed that the greatest heat is
brought to bear on TT near their junction with UU, the "uptake" tubes;
and that every succeeding passage of the pipes brings the gradually
cooling gases nearer to the "downtake" tubes SS.

The pipes TT are easily brushed and scraped after the removal of plugs
from the "headers" into which the tube ends are expanded.

Other well-known water-tube boilers are the Yarrow, Belleville,
Stirling, and Thorneycroft, all used for driving marine engines.


FIRE-TUBE BOILERS.

Fig. 6 shows a locomotive boiler in section. To the right is the
fire-box, surrounded on all sides by a water-jacket in direct
communication with the barrel of the boiler. The inner shell of the
fire-box is often made of copper, which withstands the fierce heat
better than steel; the outer, like the rest of the boiler, is of steel
plates from 1/2 to 3/4 inch thick. The shells of the jacket are braced
together by a large number of rivets, RR; and the top, or crown, is
strengthened by heavy longitudinal girders riveted to it, or is braced
to the top of the boiler by long bolts. A large number of fire-tubes
(only three are shown in the diagram for the sake of simplicity) extend
from the fire-box to the smoke-box. The most powerful "mammoth" American
locomotives have 350 or more tubes, which, with the fire-box, give 4,000
square feet of surface for the furnace heat to act upon. These tubes
are expanded at their ends by a special tool into the tube-plates of the
fire-box and boiler front. George Stephenson and his predecessors
experienced great difficulty in rendering the tube-end joints quite
water-tight, but the invention of the "expander" has removed this
trouble.

The _fire-brick arch_ shown (Fig. 6) in the fire-box is used to deflect
the flames towards the back of the fire-box, so that the hot gases may
be retarded somewhat, and their combustion rendered more perfect. It
also helps to distribute the heat more evenly over the whole of the
inside of the box, and prevents cold air from flying directly from the
firing door to the tubes. In some American and Continental locomotives
the fire-brick arch is replaced by a "water bridge," which serves the
same purpose, while giving additional heating surface.

The water circulation in a locomotive boiler is--upwards at the fire-box
end, where the heat is most intense; forward along the surface;
downwards at the smoke-box end; backwards along the bottom of the
barrel.


OTHER TYPES OF BOILERS.

For small stationary land engines the _vertical_ boiler is much used.
In Fig. 8 we have three forms of this type--A and B with cross
water-tubes; C with vertical fire-tubes. The furnace in every case is
surrounded by water, and fed through a door at one side.

[Illustration: FIG. 8.--Diagrammatic representation of three types of
vertical boilers.]

The _Lancashire_ boiler is of large size. It has a cylindrical shell,
measuring up to 30 feet in length and 7 feet in diameter, traversed from
end to end by two large flues, in the rear part of which are situated
the furnaces. The boiler is fixed on a seating of fire-bricks, so built
up as to form three flues, A and BB, shown in cross section in Fig. 9.
The furnace gases, after leaving the two furnace flues, are deflected
downwards into the channel A, by which they pass underneath the boiler
to a point almost under the furnace, where they divide right and left
and travel through cross passages into the side channels BB, to be led
along the boiler's flanks to the chimney exit C. By this arrangement the
effective heating surface is greatly increased; and the passages being
large, natural draught generally suffices to maintain proper combustion.
The Lancashire boiler is much used in factories and (in a modified form)
on ships, since it is a steady steamer and is easily kept in order.

[Illustration: FIG. 9.--Cross and longitudinal sections of a Lancashire
boiler.]

In marine boilers of cylindrical shape cross water-tubes and fire-tubes
are often employed to increase the heating surface. Return tubes are
also led through the water to the funnels, situated at the same end as
the furnace.


AIDS TO COMBUSTION.

We may now turn our attention more particularly to the chemical process
called _combustion_, upon which a boiler depends for its heat. Ordinary
steam coal contains about 85 per cent. of carbon, 7 per cent. of oxygen,
and 4 per cent. of hydrogen, besides traces of nitrogen and sulphur and
a small incombustible residue. When the coal burns, the nitrogen is
released and passes away without combining with any of the other
elements. The sulphur unites with hydrogen and forms sulphuretted
hydrogen (also named sulphurous acid), which is injurious to steel
plates, and is largely responsible for the decay of tubes and funnels.
More of the hydrogen unites with the oxygen as steam.

The most important element in coal is the carbon (known chemically by
the symbol C). Its combination with oxygen, called combustion, is the
act which heats the boiler. Only when the carbon present has combined
with the greatest possible amount of oxygen that it will take into
partnership is the combustion complete and the full heat-value (fixed by
scientific experiment at 14,500 thermal units per pound of carbon)
developed.

Now, carbon may unite with oxygen, atom for atom, and form _carbon
monoxide_ (CO); or in the proportion of one atom of carbon to _two_ of
oxygen, and form _carbon dioxide_ (CO_2). The former gas is
combustible--that is, will admit another atom of carbon to the
molecule--but the latter is saturated with oxygen, and will not burn,
or, to put it otherwise, is the product of _perfect_ combustion. A
properly designed furnace, supplied with a due amount of air, will cause
nearly all the carbon in the coal burnt to combine with the full amount
of oxygen. On the other hand, if the oxygen supply is inefficient, CO as
well as CO_2 will form, and there will be a heat loss, equal in
extreme cases to two-thirds of the whole. It is therefore necessary that
a furnace which has to eat up fuel at a great pace should be
artificially fed with air in the proportion of from 12 to 20 _pounds_ of
air for every pound of fuel. There are two methods of creating a violent
draught through the furnace. The first is--

The _forced draught_; very simply exemplified by the ordinary bellows
used in every house. On a ship (Fig. 10) the principle is developed as
follows:--The boilers are situated in a compartment or compartments
having no communication with the outer air, except for the passages down
which air is forced by powerful fans at a pressure considerably greater
than that of the atmosphere. There is only one "way out"--namely,
through the furnace and tubes (or gas-ways) of the boiler, and the
funnel. So through these it rushes, raising the fuel to white heat. As
may easily be imagined, the temperature of a stokehold, especially in
the tropics, is far from pleasant. In the Red Sea the thermometer
sometimes rises to 170° Fahrenheit or more, and the poor stokers have a
very bad time of it.

[Illustration: FIG. 10.--Sketch showing how the "forced draught" is
produced in a stokehold and how it affects the furnaces.]

[Illustration: SCENE IN THE STOKEHOLD OF A BATTLE-SHIP.]

The second system is that of the _induced draught_. Here air is
_sucked_ through the furnace by creating a vacuum in the funnel and in a
chamber opening into it. Turning to Fig. 6, we see a pipe through which
the exhaust steam from the locomotive's cylinders is shot upwards into
the funnel, in which, and in the smoke-box beneath it, a strong vacuum
is formed while the engine is running. Now, "nature abhors a vacuum," so
air will get into the smoke-box if there be a way open. There
is--through the air-doors at the bottom of the furnace, the furnace
itself, and the fire-tubes; and on the way oxygen combines with the
carbon of the fuel, to form carbon dioxide. The power of the draught is
so great that, as one often notices when a train passes during the
night, red-hot cinders, plucked from the fire-box, and dragged through
the tubes, are hurled far into the air. It might be mentioned in
parenthesis that the so-called "smoke" which pours from the funnel of a
moving engine is mainly condensing steam. A steamship, on the other
hand, belches smoke only from its funnels, as fresh water is far too
precious to waste as steam. We shall refer to this later on (p. 72).


BOILER FITTINGS.

The most important fittings on a boiler are:--(1) the safety-valve; (2)
the water-gauge; (3) the steam-gauge; (4) the mechanisms for feeding it
with water.


THE SAFETY-VALVE.

Professor Thurston, an eminent authority on the steam-engine, has
estimated that a plain cylindrical boiler carrying 100 lbs. pressure to
the square inch contains sufficient stored energy to project it into the
air a vertical distance of 3-1/2 miles. In the case of a Lancashire
boiler at equal pressure the distance would be 2-1/2 miles; of a
locomotive boiler, at 125 lbs., 1-1/2 miles; of a steam tubular boiler,
at 75 lbs., 1 mile. According to the same writer, a cubic foot of heated
water under a pressure of from 60 to 70 lbs. per square inch has _about
the same energy as one pound of gunpowder_.

Steam is a good servant, but a terrible master. It must be kept under
strict control. However strong a boiler may be, it will burst if the
steam pressure in it be raised to a certain point; and some device must
therefore be fitted on it which will give the steam free egress before
that point is reached. A device of this kind is called a _safety-valve_.
It usually blows off at less than half the greatest pressure that the
boiler has been proved by experiment to be capable of withstanding.

In principle the safety-valve denotes an orifice closed by an
accurately-fitting plug, which is pressed against its seat on the boiler
top by a weighted lever, or by a spring. As soon as the steam pressure
on the face of the plug exceeds the counteracting force of the weight
or spring, the plug rises, and steam escapes until equilibrium of the
opposing forces is restored.

On stationary engines a lever safety-valve is commonly employed (Fig.
11). The blowing-off point can be varied by shifting the weight along
the arm so as to give it a greater or less leverage. On locomotive and
marine boilers, where shocks and movements have to be reckoned with,
weights are replaced by springs, set to a certain tension, and locked up
so that they cannot be tampered with.

[Illustration: FIG. 11.--A LEVER SAFETY-VALVE. V, valve; S, seating; P,
pin; L, lever; F, fulcrum; W, weight. The figures indicate the positions
at which the weight should be placed for the valve to act when the
pressure rises to that number of pounds per square inch.]

Boilers are tested by filling the boilers quite full and (1) by heating
the water, which expands slightly, but with great pressure; (2) by
forcing in additional water with a powerful pump. In either case a
rupture would not be attended by an explosion, as water is very
inelastic.

The days when an engineer could "sit on the valves"--that is, screw them
down--to obtain greater pressure, are now past, and with them a
considerable proportion of the dangers of high-pressure steam. The
Factory Act of 1895, in force throughout the British Isles, provides
that every boiler for generating steam in a factory or workshop where
the Act applies must have a proper safety-valve, steam-gauge, and
water-gauge; and that boilers and fittings must be examined by a
competent person at least once in every fourteen months. Neglect of
these provisions renders the owner of a boiler liable to heavy penalties
if an explosion occurs.

One of the most disastrous explosions on record took place at the Redcar
Iron Works, Yorkshire, in June 1895. In this case, twelve out of fifteen
boilers ranged side by side burst, through one proving too weak for its
work. The flying fragments of this boiler, striking the sides of other
boilers, exploded them, and so the damage was transmitted down the line.
Twenty men were killed and injured; while masses of metal, weighing
several tons each, were hurled 250 yards, and caused widespread damage.

The following is taken from a journal, dated December 22, 1895:
"_Providence_ (_Rhode Island_).--A recent prophecy that a boiler would
explode between December 16 and 24 in a store has seriously affected the
Christmas trade. Shoppers are incredibly nervous. One store advertises,
'No boilers are being used; lifts running electrically.' All stores have
had their boilers inspected."


THE WATER-GAUGE.

No fitting of a boiler is more important than the _water-gauge_, which
shows the level at which the water stands. The engineer must continually
consult his gauge, for if the water gets too low, pipes and other
surfaces exposed to the furnace flames may burn through, with disastrous
results; while, on the other hand, too much water will cause bad
steaming. A section of an ordinary gauge is seen in Fig. 12. It consists
of two parts, each furnished with a gland, G, to make a steam-tight
joint round the glass tube, which is inserted through the hole covered
by the plug P^1. The cocks T^1 T^2 are normally open, allowing the
ingress of steam and water respectively to the tube. Cock T^3 is kept
closed unless for any reason it is necessary to blow steam or water
through the gauge. The holes C C can be cleaned out if the plugs P^2
P^3 are removed.

Most gauges on high-pressure boilers have a thick glass screen in front,
so that in the event of the tube breaking, the steam and water may not
blow directly on to the attendants. A further precaution is to include
two ball-valves near the ends of the gauge-glass. Under ordinary
conditions the balls lie in depressions clear of the ways; but when a
rush of steam or water occurs they are sucked into their seatings and
block all egress.

[Illustration: FIG. 12.--Section of a water-gauge.]

On many boilers two water-gauges are fitted, since any gauge may work
badly at times. The glasses are tested to a pressure of 3,000 lbs. or
more to the square inch before use.


THE STEAM-GAUGE.

It is of the utmost importance that a person in charge of a boiler
should know what pressure the steam has reached. Every boiler is
therefore fitted with one _steam-gauge_; many with two, lest one might
be unreliable. There are two principal types of steam-gauge:--(1) The
Bourdon; (2) the Schäffer-Budenberg. The principle of the Bourdon is
illustrated by Fig. 13, in which A is a piece of rubber tubing closed at
one end, and at the other drawn over the nozzle of a cycle tyre
inflator. If bent in a curve, as shown, the section of the tube is an
oval. When air is pumped in, the rubber walls endeavour to assume a
circular section, because this shape encloses a larger area than an oval
of equal circumference, and therefore makes room for a larger volume of
air. In doing so the tube straightens itself, and assumes the position
indicated by the dotted lines. Hang an empty "inner tube" of a pneumatic
tyre over a nail and inflate it, and you will get a good illustration of
the principle.

[Illustration: FIG. 13.--Showing the principle of the steam-gauge.]

[Illustration: FIG. 14.--Bourdon steam-gauge. Part of dial removed to
show mechanism.]

In Fig. 14 we have a Bourdon gauge, with part of the dial face broken
away to show the internal mechanism. T is a flattened metal tube
soldered at one end into a hollow casting, into which screws a tap
connected with the boiler. The other end (closed) is attached to a link,
L, which works an arm of a quadrant rack, R, engaging with a small
pinion, P, actuating the pointer. As the steam pressure rises, the tube
T moves its free end outwards towards the position shown by the dotted
lines, and traverses the arm of the rack, so shifting the pointer round
the scale. As the pressure falls, the tube gradually returns to its zero
position.

The Schäffer-Budenberg gauge depends for its action on the elasticity of
a thin corrugated metal plate, on one side of which steam presses. As
the plate bulges upwards it pushes up a small rod resting on it, which
operates a quadrant and rack similar to that of the Bourdon gauge. The
principle is employed in another form for the aneroid barometer (p.
329).


THE WATER SUPPLY TO A BOILER.

The water inside a boiler is kept at a proper level by (1) pumps or (2)
injectors. The former are most commonly used on stationary and marine
boilers. As their mechanism is much the same as that of ordinary force
pumps, which will be described in a later chapter, we may pass at once
to the _injector_, now almost universally used on locomotive, and
sometimes on stationary boilers. At first sight the injector is a
mechanical paradox, since it employs the steam from a boiler to blow
water into the boiler. In Fig. 15 we have an illustration of the
principle of an injector. Steam is led from the boiler through pipe A,
which terminates in a nozzle surrounded by a cone, E, connected by the
pipe B with the water tank. When steam is turned on it rushes with
immense velocity from the nozzle, and creates a partial vacuum in cone
E, which soon fills with water. On meeting the water the steam
condenses, but not before it has imparted some of its _velocity_ to the
water, which thus gains sufficient momentum to force down the valve and
find its way to the boiler. The overflow space O O between E and C
allows steam and water to escape until the water has gathered the
requisite momentum.

[Illustration: FIG. 15.--Diagram illustrating the principle of a
steam-injector.]

[Illustration: FIG. 16.--The Giffard injector.]

A form of injector very commonly used is Giffard's (Fig. 16). Steam is
allowed to enter by screwing up the valve V. As it rushes through the
nozzle of the cone A it takes up water and projects it into the "mixing
cone" B, which can be raised or lowered by the pinion D (worked by the
hand-wheel wheel shown) so as to regulate the amount of water admitted
to B. At the centre of B is an aperture, O, communicating with the
overflow. The water passes to the boiler through the valve on the left.
It will be noticed that the cone A and the part of B above the orifice O
contract downward. This is to convert the _pressure_ of the steam into
_velocity_. Below O is a cone, the diameter of which increases
downwards. Here the _velocity_ of the water is converted back into
_pressure_ in obedience to a well-known hydromechanic law.

An injector does not work well if the feed-water be too hot to condense
the steam quickly; and it may be taken as a rule that the warmer the
water, the smaller is the amount of it injected by a given weight of
steam.[2] Some injectors have flap-valves covering the overflow orifice,
to prevent air being sucked in and carried to the boiler.

When an injector receives a sudden shock, such as that produced by the
passing of a locomotive over points, it is liable to "fly off"--that is,
stop momentarily--and then send the steam and water through the
overflow. If this happens, both steam and water must be turned off, and
the injector be restarted; unless it be of the _self-starting_ variety,
which automatically controls the admission of water to the
"mixing-cone," and allows the injector to "pick up" of itself.

For economy's sake part of the steam expelled from the cylinders of a
locomotive is sometimes used to work an injector, which passes the water
on, at a pressure of 70 lbs. to the square inch, to a second injector
operated by high-pressure steam coming direct from the boiler, which
increases its velocity sufficiently to overcome the boiler pressure. In
this case only a fraction of the weight of high-pressure steam is
required to inject a given weight of water, as compared with that used
in a single-stage injector.


[1] "The Steam-Engine," p. 3.

[2] By "weight of steam" is meant the steam produced by boiling a
certain weight of water. A pound of steam, if condensed, would form a
pound of water.




Chapter II.

THE CONVERSION OF HEAT ENERGY INTO MECHANICAL MOTION.

     Reciprocating engines--Double-cylinder engines--The function of the
     fly-wheel--The cylinder--The slide-valve--The eccentric--"Lap" of
     the valve: expansion of steam--How the cut-off is managed--Limit of
     expansive working--Compound engines--Arrangement of expansion
     engines--Compound locomotives--Reversing
     gears--"Linking-up"--Piston-valves--Speed governors--Marine-speed
     governors--The condenser.


Having treated at some length the apparatus used for converting water
into high-pressure steam, we may pass at once to a consideration of the
mechanisms which convert the energy of steam into mechanical motion, or
_work_.

Steam-engines are of two kinds:--(1) _reciprocating_, employing
cylinders and cranks; (2) _rotary_, called turbines.


RECIPROCATING ENGINES.

[Illustration: FIG. 17.--Sketch showing parts of a horizontal
steam-engine.]

Fig. 17 is a skeleton diagram of the simplest form of reciprocating
engine. C is a _cylinder_ to which steam is admitted through the
_steam-ways_[3] W W, first on one side of the piston P, then on the
other. The pressure on the piston pushes it along the cylinder, and the
force is transmitted through the piston rod P R to the _connecting rod_
C R, which causes the _crank_ K to revolve. At the point where the two
rods meet there is a "crosshead," H, running to and fro in a guide to
prevent the piston rod being broken or bent by the oblique thrusts and
pulls which it imparts through C R to the crank K. The latter is keyed
to a _shaft_ S carrying the fly-wheel, or, in the case of a locomotive,
the driving-wheels. The crank shaft revolves in bearings. The internal
diameter of a cylinder is called its _bore_. The travel of the piston is
called its _stroke_. The distance from the centre of the shaft to the
centre of the crank pin is called the crank's _throw_, which is half of
the piston's _stroke_. An engine of this type is called double-acting,
as the piston is pushed alternately backwards and forwards by the steam.
When piston rod, connecting rod, and crank lie in a straight line--that
is, when the piston is fully out, or fully in--the crank is said to be
at a "dead point;" for, were the crank turned to such a position, the
admission of steam would not produce motion, since the thrust or pull
would be entirely absorbed by the bearings.

[Illustration: FIG. 18.--Sectional plan of a horizontal engine.]


DOUBLE-CYLINDER ENGINES.

[Illustration: FIG. 19.]

[Illustration: FIG. 20.]

Locomotive, marine, and all other engines which must be started in any
position have at least _two_ cylinders, and as many cranks set at an
angle to one another. Fig. 19 demonstrates that when one crank, C_1,
of a double-cylinder engine is at a "dead point," the other, C_2, has
reached a position at which the piston exerts the maximum of turning
power. In Fig. 20 each crank is at 45° with the horizontal, and both
pistons are able to do work. The power of one piston is constantly
increasing while that of the other is decreasing. If _single_-action
cylinders are used, at least _three_ of these are needed to produce a
perpetual turning movement, independently of a fly-wheel.


THE FUNCTION OF THE FLY-WHEEL.

A fly-wheel acts as a _reservoir of energy_, to carry the crank of a
single-cylinder engine past the "dead points." It is useful in all
reciprocating engines to produce steady running, as a heavy wheel acts
as a drag on the effects of a sudden increase or decrease of steam
pressure. In a pump, mangold-slicer, cake-crusher, or chaff-cutter, the
fly-wheel helps the operator to pass _his_ dead points--that is, those
parts of the circle described by the handle in which he can do little
work.


THE CYLINDER.

[Illustration: FIG. 21.--Diagrammatic section of a cylinder and its
slide-valve.]

The cylinders of an engine take the place of the muscular system of the
human body. In Fig. 21 we have a cylinder and its slide-valve shown in
section. First of all, look at P, the piston. Round it are white
grooves, R R, in which rings are fitted to prevent the passage of steam
past the piston. The rings are cut through at one point in their
circumference, and slightly opened, so that when in position they press
all round against the walls of the cylinder. After a little use they
"settle down to their work"--that is, wear to a true fit in the
cylinder. Each end of the cylinder is closed by a cover, one of which
has a boss cast on it, pierced by a hole for the piston rod to work
through. To prevent the escape of steam the boss is hollowed out true to
accommodate a _gland_, G^1, which is threaded on the rod and screwed
up against the boss; the internal space between them being filled with
packing. Steam from the boiler enters the steam-chest, and would have
access to both sides of the piston simultaneously through the
steam-ways, W W, were it not for the


SLIDE-VALVE,

a hollow box open at the bottom, and long enough for its edges to cover
both steam-ways at once. Between W W is E, the passage for the exhaust
steam to escape by. The edges of the slide-valve are perfectly flat, as
is the face over which the valve moves, so that no steam may pass under
the edges. In our illustration the piston has just begun to move towards
the right. Steam enters by the left steam-way, which the valve is just
commencing to uncover. As the piston moves, the valve moves in the same
direction until the port is fully uncovered, when it begins to move back
again; and just before the piston has finished its stroke the steam-way
on the right begins to open. The steam-way on the left is now in
communication with the exhaust port E, so that the steam that has done
its duty is released and pressed from the cylinder by the piston.
_Reciprocation_ is this backward and forward motion of the piston: hence
the term "reciprocating" engines. The linear motion of the piston rod is
converted into rotatory motion by the connecting rod and crank.

[Illustration: FIG. 22.--Perspective section of cylinder.]

The use of a crank appears to be so obvious a method of producing this
conversion that it is interesting to learn that, when James Watt
produced his "rotative engine" in 1780 he was unable to use the crank
because it had already been patented by one Matthew Wasborough. Watt was
not easily daunted, however, and within a twelvemonth had himself
patented five other devices for obtaining rotatory motion from a piston
rod. Before passing on, it may be mentioned that Watt was the father of
the modern--that is, the high-pressure--steam-engine; and that, owing to
the imperfection of the existing machinery, the difficulties he had to
overcome were enormous. On one occasion he congratulated himself because
one of his steam-cylinders was only three-eighths of an inch out of
truth in the bore. Nowadays a good firm would reject a cylinder 1/500 of
an inch out of truth; and in small petrol-engines 1/5000 of an inch is
sometimes the greatest "limit of error" allowed.


[Illustration: FIG. 23.--The eccentric and its rod.]

THE ECCENTRIC

is used to move the slide-valve to and fro over the steam ports (Fig.
23). It consists of three main parts--the _sheave_, or circular plate S,
mounted on the crank shaft; and the two _straps_ which encircle it, and
in which it revolves. To one strap is bolted the "big end" of the
eccentric rod, which engages at its other end with the valve rod. The
straps are semicircular and held together by strong bolts, B B, passing
through lugs, or thickenings at the ends of the semicircles. The sheave
has a deep groove all round the edges, in which the straps ride. The
"eccentricity" or "throw" of an eccentric is the distance between C^2,
the centre of the shaft, and C^1, the centre of the sheave. The throw
must equal half of the distance which the slide-valve has to travel over
the steam ports. A tapering steel wedge or key, K, sunk half in the
eccentric and half in a slot in the shaft, holds the eccentric steady
and prevents it slipping. Some eccentric sheaves are made in two parts,
bolted together, so that they may be removed easily without dismounting
the shaft.

The eccentric is in principle nothing more than a crank pin so
exaggerated as to be larger than the shaft of the crank. Its convenience
lies in the fact that it may be mounted at any point on a shaft, whereas
a crank can be situated at an end only, if it is not actually a V-shaped
bend in the shaft itself--in which case its position is of course
permanent.


SETTING OF THE SLIDE-VALVE AND ECCENTRIC.

The subject of valve-setting is so extensive that a full exposition
might weary the reader, even if space permitted its inclusion. But
inasmuch as the effectiveness of a reciprocating engine depends largely
on the nature and arrangement of the valves, we will glance at some of
the more elementary principles.

[Illustration: FIG. 24.]

[Illustration: FIG. 25.]

In Fig. 24 we see in section the slide-valve, the ports of the cylinder,
and part of the piston. To the right are two lines at right angles--the
thicker, C, representing the position of the crank; the thinner, E, that
of the eccentric. (The position of an eccentric is denoted
diagrammatically by a line drawn from the centre of the crank shaft
through the centre of the sheave.) The edges of the valve are in this
case only broad enough to just cover the ports--that is, they have no
_lap_. The piston is about to commence its stroke towards the left; and
the eccentric, which is set at an angle of 90° in _advance_ of the
crank, is about to begin opening the left-hand port. By the time that C
has got to the position originally occupied by E, E will be horizontal
(Fig. 25)--that is, the eccentric will have finished its stroke towards
the left; and while C passes through the next right angle the valve will
be closing the left port, which will cease to admit steam when the
piston has come to the end of its travel. The operation is repeated on
the right-hand side while the piston returns.

[Illustration: FIG. 26.]

It must be noticed here--(1) that steam is admitted at full pressure
_all through_ the stroke; (2) that admission begins and ends
simultaneously with the stroke. Now, in actual practice it is necessary
to admit steam before the piston has ended its travel, so as to
_cushion_ the violence of the sudden change of direction of the piston,
its rod, and other moving parts. To effect this, the eccentric is set
more than 90° in advance--that is, more than what the engineers call
_square_. Fig. 26 shows such an arrangement. The angle between E and
E^1 is called the _angle of advance_. Referring to the valve, you will
see that it has opened an appreciable amount, though the piston has not
yet started on its rightwards journey.


"LAP" OF THE VALVE--EXPANSION OF STEAM.

In the simple form of valve that appears in Fig. 24, the valve faces are
just wide enough to cover the steam ports. If the eccentric is not
_square_ with the crank, the admission of steam lasts until the very end
of the stroke; if set a little in advance--that is, given _lead_--the
steam is cut off before the piston has travelled quite along the
cylinder, and readmitted before the back stroke is accomplished. Even
with this lead the working is very uneconomical, as the steam goes to
the exhaust at practically the same pressure as that at which it entered
the cylinder. Its property of _expansion_ has been neglected. But
supposing that steam at 100 lbs. pressure were admitted till
half-stroke, and then suddenly cut off, the expansive nature of the
steam would then continue to push the piston out until the pressure had
decreased to 50 lbs. per square inch, at which pressure it would go to
the exhaust. Now, observe that all the work done by the steam after the
cut-off is so much power saved. The _average_ pressure on the piston is
not so high as in the first case; still, from a given volume of 100 lbs.
pressure steam we get much more _work_.


HOW THE CUT-OFF IS MANAGED.

[Illustration: FIG. 27.--A slide-valve with "lap."]

[Illustration: FIG. 28.]

Look at Fig. 27. Here we have a slide-valve, with faces much wider than
the steam ports. The parts marked black, P P, are those corresponding to
the faces of the valves shown in previous diagrams (p. 54). The shaded
parts, L L, are called the _lap_. By increasing the length of the lap we
increase the range of expansive working. Fig. 28 shows the piston full
to the left; the valve is just on the point of opening to admit steam
behind the piston. The eccentric has a throw equal to the breadth of a
port + the lap of the valve. That this must be so is obvious from a
consideration of Fig. 27, where the valve is at its central position.
Hence the very simple formula:--Travel of valve = 2 × (lap + breadth of
port). The path of the eccentric's centre round the centre of the shaft
is indicated by the usual dotted line (Fig. 28). You will notice that
the "angle of advance," denoted by the arrow A, is now very
considerable. By the time that the crank C has assumed the position of
the line S, the eccentric has passed its dead point, and the valve
begins to travel backwards, eventually returning to the position shown
in Fig. 28, and cutting off the steam supply while the piston has still
a considerable part of its stroke to make. The steam then begins to work
expansively, and continues to do so until the valve assumes the position
shown in Fig. 27.

If the valve has to have "lead" to admit steam _before_ the end of the
stroke to the other side of the piston, the _angle of advance_ must be
increased, and the eccentric centre line would lie on the line E^2.
Therefore--total angle of advance = angle for _lap_ and angle for
_lead_.


LIMIT OF EXPANSIVE WORKING.

Theoretically, by increasing the _lap_ and cutting off the steam earlier
and earlier in the stroke, we should economize our power more and more.
But in practice a great difficulty is met with--namely, that _as the
steam expands its temperature falls_. If the cut-off occurs early, say
at one-third stroke, the great expansion will reduce the temperature of
the metal walls of the cylinder to such an extent, that when the next
spirt of steam enters from the other end a considerable proportion of
the steam's energy will be lost by cooling. In such a case, the
difference in temperature between admitted steam and exhausted steam is
too great for economy. Yet we want to utilize as much energy as
possible. How are we to do it?


COMPOUND ENGINES.

In the year 1853, John Elder, founder of the shipping firm of Elder and
Co., Glasgow, introduced the _compound_ engine for use on ships. The
steam, when exhausted from the high-pressure cylinder, passed into
another cylinder of equal stroke but larger diameter, where the
expansion continued. In modern engines the expansion is extended to
three and even four stages, according to the boiler pressure; for it is
a rule that the higher the initial pressure is, the larger is the number
of stages of expansion consistent with economical working.

[Illustration: FIG. 29.--Sketch of the arrangement of a
triple-expansion marine engine. No valve gear or supports, etc., shown.]

In Fig. 29 we have a triple-expansion marine engine. Steam enters the
high-pressure cylinder[4] at, say, 200 lbs. per square inch. It exhausts
at 75 lbs. into the large pipe 2, and passes to the intermediate
cylinder, whence it is exhausted at 25 lbs. or so through pipe 3 to the
low-pressure cylinder. Finally, it is ejected at about 8 lbs. per square
inch to the condenser, and is suddenly converted into water; an act
which produces a vacuum, and diminishes the back-pressure of the exhaust
from cylinder C. In fact, the condenser exerts a _sucking_ power on the
exhaust side of C's piston.


ARRANGEMENT OF EXPANSION ENGINES.

In the illustration the cranks are set at angles of 120°, or a third of
a circle, so that one or other is always at or near the position of
maximum turning power. Where only two stages are used the cylinders are
often arranged _tandem_, both pistons having a common piston rod and
crank. In order to get a constant turning movement they must be mounted
separately, and work cranks set at right angles to one another.


COMPOUND LOCOMOTIVES.

In 1876 Mr. A. Mallet introduced _compounding_ in locomotives; and the
practice has been largely adopted. The various types of "compounds" may
be classified as follows:--(1) One low-pressure and one high-pressure
cylinder; (2) one high-pressure and two low-pressure; (3) one
low-pressure and two high-pressure; (4) two high-pressure and two
low-pressure. The last class is very widely used in France, America, and
Russia, and seems to give the best results. Where only two cylinders are
used (and sometimes in the case of three and four), a valve arrangement
permits the admission of high-pressure steam to both high and
low-pressure cylinders for starting a train, or moving it up heavy
grades.


REVERSING GEARS.

[Illustration: FIGS. 30, 31, 32.--Showing how a reversing gear alters
the position of the slide-valve.]

The engines of a locomotive or steamship must be reversible--that is,
when steam is admitted to the cylinders, the engineer must be able to
so direct it through the steam-ways that the cranks may turn in the
desired direction. The commonest form of reversing device (invented by
George Stephenson) is known as Stephenson's Link Gear. In Fig. 30 we
have a diagrammatic presentment of this gear. E^1 and E^2 are two
eccentrics set square with the crank at opposite ends of a diameter.
Their rods are connected to the ends of a link, L, which can be raised
and lowered by means of levers (not shown). B is a block which can
partly revolve on a pin projecting from the valve rod, working through
a guide, G. In Fig. 31 the link is half raised, or in "mid-gear," as
drivers say. Eccentric E^1 has pushed the lower end of the link fully
back; E^2 has pulled it fully forward; and since any movement of the
one eccentric is counterbalanced by the opposite movement of the other,
rotation of the eccentrics would not cause the valve to move at all, and
no steam could be admitted to the cylinder.

Let us suppose that Fig. 30 denotes one cylinder, crank, rods, etc., of
a locomotive. The crank has come to rest at its half-stroke; the
reversing lever is at the mid-gear notch. If the engineer desires to
turn his cranks in an anti-clockwise direction, he _raises_ the link,
which brings the rod of E^1 into line with the valve rod and presses
the block _backwards_ till the right-hand port is uncovered (Fig. 31).
If steam be now admitted, the piston will be pushed towards the left,
and the engine will continue to run in an anti-clockwise direction. If,
on the other hand, he wants to run the engine the other way, he would
_drop_ the link, bringing the rod of E^2 into line with the valve rod,
and drawing V _forward_ to uncover the rear port (Fig. 32). In either
case the eccentric working the end of the link remote from B has no
effect, since it merely causes that end to describe arcs of circles of
which B is the centre.


"LINKING UP."

If the link is only partly lowered or raised from the central position
it still causes the engine to run accordingly, but the movement of the
valve is decreased. When running at high speed the engineer "links up"
his reversing gear, causing his valves to cut off early in the stroke,
and the steam to work more expansively than it could with the lever at
_full_, or _end_, gear; so that this device not only renders an engine
reversible, but also gives the engineer an absolute command over the
expansion ratio of the steam admitted to the cylinder, and furnishes a
method of cutting off the steam altogether. In Figs. 30, 31, 32, the
valve has no lap and the eccentrics are set square. In actual practice
the valve faces would have "lap" and the eccentric "lead" to correspond;
but for the sake of simplicity neither is shown.


OTHER GEARS.

In the Gooch gear for reversing locomotives the link does not shift, but
the valve rod and its block is raised or lowered. The Allan gear is so
arranged that when the link is raised the block is lowered, and _vice
versâ_. These are really only modifications of Stephenson's
principle--namely, the employment of _two_ eccentrics set at equal
angles to and on opposite sides of the crank. There are three other
forms of link-reversing gear, and nearly a dozen types of _radial_
reversing devices; but as we have already described the three most
commonly used on locomotives and ships, there is no need to give
particulars of these.

Before the introduction of Stephenson's gear a single eccentric was used
for each cylinder, and to reverse the engine this eccentric had to be
loose on the axle. "A lever and gear worked by a treadle on the
footplate controlled the position of the eccentrics. When starting the
engine, the driver put the eccentrics out of gear by the treadle; then,
by means of a lever he raised the small-ends[5] of the eccentric rods,
and, noting the position of the cranks, or, if more convenient, the
balance weight in the wheels, he, by means of another handle, moved the
valves to open the necessary ports to steam and worked them by hand
until the engine was moving; then, with the treadle, he threw the
eccentrics over to engage the studs, at the same time dropping the
small-ends of the rods to engage pins upon the valve spindles, so that
they continued to keep up the movement of the valve."[6] One would
imagine that in modern shunting yards such a device would somewhat delay
operations!


PISTON VALVES.

In marine engines, and on many locomotives and some stationary engines,
the D-valve (shown in Figs. 30-32) is replaced by a piston valve, or
circular valve, working up and down in a tubular seating. It may best be
described as a rod carrying two pistons which correspond to the faces of
a D-valve. Instead of rectangular ports there are openings in the tube
in which the piston valve moves, communicating with the steam-ways into
the cylinder and with the exhaust pipe. In the case of the D-valve the
pressure above it is much greater than that below, and considerable
friction arises if the rubbing faces are not kept well lubricated. The
piston valve gets over this difficulty, since such steam as may leak
past it presses on its circumference at all points equally.


SPEED GOVERNORS.

[Illustration: FIG. 33.--A speed governor.]

Practically all engines except locomotives and those known as
"donkey-engines"--used on cranes--are fitted with some device for
keeping the rotatory speed of the crank constant within very narrow
limits. Perhaps you have seen a pair of balls moving round on a seating
over the boiler of a threshing-engine. They form part of the "governor,"
or speed-controller, shown in principle in Fig. 33. A belt driven by a
pulley on the crank shaft turns a small pulley, P, at the foot of the
governor. This transmits motion through two bevel-wheels, G, to a
vertical shaft, from the top of which hang two heavy balls on links, K
K. Two more links, L L, connect the balls with a weight, W, which has a
deep groove cut round it at the bottom. When the shaft revolves, the
balls fly outwards by centrifugal force, and as their velocity increases
the quadrilateral figure contained by the four links expands laterally
and shortens vertically. The angles between K K and L L become less and
less obtuse, and the weight W is drawn upwards, bringing with it the
fork C of the rod A, which has ends engaging with the groove. As C
rises, the other end of the rod is depressed, and the rod B depresses
rod O, which is attached to the spindle operating a sort of shutter in
the steam-pipe. Consequently the supply of steam is throttled more and
more as the speed increases, until it has been so reduced that the
engine slows, and the balls fall, opening the valve again. Fig. 34 shows
the valve fully closed. This form of governor was invented by James
Watt. A spring is often used instead of a weight, and the governor is
arranged horizontally so that it may be driven direct from the crank
shaft without the intervention of bevel gearing.

[Illustration: FIG. 34.]

The Hartwell governor employs a link motion. You must here picture the
balls raising and lowering the _free end_ of the valve rod, which
carries a block moving in a link connected with the eccentric rod. The
link is pivoted at the upper end, and the eccentric rod is attached to
the lower. When the engine is at rest the end of the valve rod and its
block are dropped till in a line with the eccentric rod; but when the
machinery begins to work the block is gradually drawn up by the
governor, diminishing the movement of the valve, and so shortening the
period of steam admission to the cylinder.

Governors are of special importance where the _load_ of an engine is
constantly varying, as in the case of a sawmill. A good governor will
limit variation of speed within two per cent.--that is, if the engine is
set to run at 100 revolutions a minute, it will not allow it to exceed
101 or fall below 99. In _very_ high-speed engines the governing will
prevent variation of less than one per cent., even when the load is at
one instant full on, and the next taken completely off.


MARINE GOVERNORS.

These must be more quick-acting than those used on engines provided with
fly-wheels, which prevent very sudden variations of speed. The screw is
light in proportion to the engine power, and when it is suddenly raised
from the water by the pitching of the vessel, the engine would race till
the screw took the water again, unless some regulating mechanism were
provided. Many types of marine governors have been tried. The most
successful seems to be one in which water is being constantly forced by
a pump driven off the engine shaft into a cylinder controlling a
throttle-valve in the main steam-pipe. The water escapes through a leak,
which is adjustable. As long as the speed of the engine is normal, the
water escapes from the cylinder as fast as it is pumped in, and no
movement of the piston results; but when the screw begins to race, the
pump overcomes the leak, and the piston is driven out, causing a
throttling of the steam supply.


CONDENSERS.

The _condenser_ serves two purposes:--(1) It makes it possible to use
the same water over and over again in the boilers. On the sea, where
fresh water is not obtainable in large quantities, this is a matter of
the greatest importance. (2) It adds to the power of a compound engine
by exerting a back pull on the piston of the low-pressure cylinder while
the steam is being exhausted.

[Illustration: FIG. 35.--The marine condenser.]

Fig. 35 is a sectional illustration of a marine condenser. Steam enters
the condenser through the large pipe E, and passes among a number of
very thin copper tubes, through which sea-water is kept circulating by a
pump. The path of the water is shown by the featherless arrows. It comes
from the pump through pipe A into the lower part of a large cap covering
one end of the condenser and divided transversely by a diaphragm, D.
Passing through the pipes, it reaches the cap attached to the other end,
and flows back through the upper tubes to the outlet C. This arrangement
ensures that, as the steam condenses, it shall meet colder and colder
tubes, and finally be turned to water, which passes to the well through
the outlet F. In some condensers the positions of steam and water are
reversed, steam going through the tubes outside which cold water
circulates.


[3] Also called _ports_.

[4] The bores of the cylinders are in the proportion of 4: 6: 9. The
stroke of all three is the same.

[5] The ends furthest from the eccentric.

[6] "The Locomotive of To-day," p. 87.




Chapter III.

THE STEAM TURBINE.

     How a turbine works--The De Laval turbine--The Parsons
     turbine--Description of the Parsons turbine--The expansive action
     of steam in a Parsons turbine--Balancing the thrust--Advantages of
     the marine turbine.


More than two thousand years ago Hero of Alexandria produced the first
apparatus to which the name of steam-engine could rightly be given. Its
principle was practically the same as that of the revolving jet used to
sprinkle lawns during dry weather, steam being used in the place of
water. From the top of a closed cauldron rose two vertical pipes, which
at their upper ends had short, right-angle bends. Between them was hung
a hollow globe, pivoted on two short tubes projecting from its sides
into the upright tubes. Two little L-shaped pipes projected from
opposite sides of the globe, at the ends of a diameter, in a plane
perpendicular to the axis. On fire being applied to the cauldron, steam
was generated. It passed up through the upright, through the pivots, and
into the globe, from which it escaped by the two L-shaped nozzles,
causing rapid revolution of the ball. In short, the first steam-engine
was a turbine. Curiously enough, we have reverted to this primitive type
(scientifically developed, of course) in the most modern engineering
practice.


HOW A TURBINE WORKS.

In reciprocating--that is, cylinder--engines steam is admitted into a
chamber and the door shut behind it, as it were. As it struggles to
expand, it forces out one of the confining walls--that is, the
piston--and presently the door opens again, and allows it to escape when
it has done its work. In Hero's toy the impact of the issuing molecules
against other molecules that have already emerged from the pipes was
used. One may compare the reaction to that exerted by a thrown stone on
the thrower. If the thrower is standing on skates, the reaction of the
stone will cause him to glide backwards, just as if he had pushed off
from some fixed object. In the case of the _reaction_--namely, the
Hero-type--turbine the nozzle from which the steam or water issues
moves, along with bodies to which it may be attached. In _action_
turbines steam is led through fixed nozzles or steam-ways, and the
momentum of the steam is brought to bear on the surfaces of movable
bodies connected with the shaft.


THE DE LAVAL TURBINE.

In its earliest form this turbine was a modification of Hero's. The
wheel was merely a pipe bent in S form, attached at its centre to a
hollow vertical shaft supplied with steam through a stuffing-box at one
extremity. The steam blew out tangentially from the ends of the S,
causing the shaft to revolve rapidly and work the machinery (usually a
cream separator) mounted on it. This motor proved very suitable for
dairy work, but was too wasteful of steam to be useful where high power
was needed.

[Illustration: FIG. 36.--The wheel and nozzles of a De Laval turbine.]

In the De Laval turbine as now constructed the steam is blown from
stationary nozzles against vanes mounted on a revolving wheel. Fig. 36
shows the nozzles and a turbine wheel. The wheel is made as a solid
disc, to the circumference of which the vanes are dovetailed separately
in a single row. Each vane is of curved section, the concave side
directed towards the nozzles, which, as will be gathered from the
"transparent" specimen on the right of our illustration, gradually
expand towards the mouth. This is to allow the expansion of the steam,
and a consequent gain of velocity. As it issues, each molecule strikes
against the concave face of a vane, and, while changing its direction,
is robbed of its kinetic energy, which passes to the wheel. To turn
once more to a stone-throwing comparison, it is as if a boy were pelting
the wheel with an enormous number of tiny stones. Now, escaping
high-pressure steam moves very fast indeed. To give figures, if it
enters the small end of a De Laval nozzle at 200 lbs. per square inch,
it will leave the big end at a velocity of 48 miles per _minute_--that
is, at a speed which would take it right round the world in 8-1/2 hours!
The wheel itself would not move at more than about one-third of this
speed as a maximum.[7] But even so, it may make as many as 30,000
revolutions per minute. A mechanical difficulty is now
encountered--namely, that arising from vibration. No matter how
carefully the turbine wheel may be balanced, it is practically
impossible to make its centre of gravity coincide exactly with the
central point of the shaft; in other words, the wheel will be a
bit--perhaps only a tiny fraction of an ounce--heavier on one side than
the other. This want of truth causes vibration, which, at the high speed
mentioned, would cause the shaft to knock the bearings in which it
revolves to pieces, if--and this is the point--those bearings were close
to the wheel M. de Laval mounted the wheel on a shaft long enough
between the bearings to "whip," or bend a little, and the difficulty was
surmounted.

The normal speed of the turbine wheel is too high for direct driving of
some machinery, so it is reduced by means of gearing. To dynamos, pumps,
and air-fans it is often coupled direct.


THE PARSONS TURBINE.

At the grand naval review held in 1897 in honour of Queen Victoria's
diamond jubilee, one of the most noteworthy sights was the little
_Turbinia_ of 44-1/2 tons burthen, which darted about among the floating
forts at a speed much surpassing that of the fastest "destroyer." Inside
the nimble little craft were engines developing 2,000 horse power,
without any of the clank and vibration which usually reigns in the
engine-room of a high-speed vessel. The _Turbinia_ was the first
turbine-driven boat, and as such, even apart from her extraordinary
pace, she attracted great attention. Since 1897 the Parsons turbine has
been installed on many ships, including several men-of-war, and it seems
probable that the time is not far distant when reciprocating engines
will be abandoned on all high-speed craft.


DESCRIPTION OF THE PARSONS TURBINE.

[Illustration: FIG. 37.--Section of a Parsons turbine.]

The essential parts of a Parsons turbine are:--(1) The shaft, on which
is mounted (2) the drum; (3) the cylindrical casing inside which the
drum revolves; (4) the vanes on the drum and casing; (5) the balance
pistons. Fig. 37 shows a diagrammatic turbine in section. The drum, it
will be noticed, increases its diameter in three stages, D^1, D^2,
D^3, towards the right. From end to end it is studded with little
vanes, M M, set in parallel rings small distances apart. Each vane has a
curved section (see Fig. 38), the hollow side facing towards the left.
The vanes stick out from the drum like short spokes, and their outer
ends almost touch the casing. To the latter are attached equally-spaced
rings of fixed vanes, F F, pointing inwards towards the drum, and
occupying the intervals between the rings of moving vanes. Their concave
sides also face towards the left, but, as seen in Fig. 38, their line of
curve lies the reverse way to that of M M. Steam enters the casing at A,
and at once rushes through the vanes towards the outlet at B. It meets
the first row of fixed vanes, and has its path so deflected that it
strikes the ring of moving (or drum) vanes at the most effective angle,
and pushes them round. It then has its direction changed by the ring of
F F, so that it may treat the next row of M M in a similar fashion.

[Illustration: FIG. 38.--Blades or vanes of a Parsons turbine.]

[Illustration: One of the low-pressure turbines of the _Carmania_, in
casing. Its size will be inferred from comparison with the man standing
near the end of the casing.]


THE EXPANSIVE ACTION OF STEAM IN A TURBINE.

On reaching the end of D^1 it enters the second, or intermediate, set
of vanes. The drum here is of a greater diameter, and the blades are
longer and set somewhat farther apart, to give a freer passage to the
now partly expanded steam, which has lost pressure but gained velocity.
The process of movement is repeated through this stage; and again in
D^3, the low-pressure drum. The steam then escapes to the condenser
through B, having by this time expanded very many times; and it is found
advisable, for reasons explained in connection with compound
steam-engines, to have a separate turbine in an independent casing for
the extreme stages of expansion.

The vanes are made of brass. In the turbines of the _Carmania_, the huge
Cunard liner, 1,115,000 vanes are used. The largest diameter of the
drums is 11 feet, and each low-pressure turbine weighs 350 tons.


BALANCING OF THRUST.

The push exerted by the steam on the blades not only turns the drum, but
presses it in the direction in which the steam flows. This end thrust is
counterbalanced by means of the "dummy" pistons, P^1, P^2, P^3.
Each dummy consists of a number of discs revolving between rings
projecting from the casing, the distance between discs and rings being
so small that but little steam can pass. In the high-pressure
compartment the steam pushes P^1 to the left with the same pressure as
it pushes the blades of D^1 to the right. After completing the first
stage it fills the passage C, which communicates with the second piston,
P^2, and the pressure on that piston negatives the thrust on D^2.
Similarly, the passage E causes the steam to press equally on P^3 and
the vanes of D^3. So that the bearings in which the shaft revolves
have but little thrust to take. This form of compensation is necessary
in marine as well as in stationary turbines. In the former the dummy
pistons are so proportioned that the forward thrust given by them and
the screw combined is almost equal to the thrust aft of the moving
vanes.

[Illustration: One of the turbine drums of the _Carmania_. Note the
rows of vanes. The drum is here being tested for perfect balance on two
absolutely level supports.]


ADVANTAGES OF THE MARINE TURBINE.

(1.) Absence of vibration. Reciprocating engines, however well balanced,
cause a shaking of the whole ship which is very unpleasant to
passengers. The turbine, on the other hand, being almost perfectly
balanced, runs so smoothly at the highest speeds that, if the hand be
laid on the covering, it is sometimes almost impossible to tell whether
the machinery is in motion. As a consequence of this smooth running
there is little noise in the engine-room--a pleasant contrast to the
deafening roar of reciprocating engines. (2.) Turbines occupy less room.
(3.) They are more easily tended. (4.) They require fewer repairs, since
the rubbing surfaces are very small as compared to those of
reciprocating engines. (5.) They are more economical at high speeds. It
must be remembered that a turbine is essentially meant for high speeds.
If run slowly, the steam will escape through the many passages without
doing much work.

Owing to its construction, a turbine cannot be reversed like a cylinder
engine. It therefore becomes necessary to fit special astern turbines to
one or more of the screw shafts, for use when the ship has to be stopped
or moved astern. Under ordinary conditions these turbines revolve idly
in their cases.

The highest speed ever attained on the sea was the forty-two miles per
hour of the unfortunate _Viper_, a turbine destroyer which developed
11,500 horse power, though displacing only 370 tons. This velocity would
compare favourably with that of a good many expresses on certain
railways that we could name. In the future thirty miles an hour will
certainly be attained by turbine-driven liners.


[7] Even at this speed the wheel has a circumferential velocity of
two-thirds that of a bullet shot from a Lee-Metford rifle. A vane
weighing only 250 grains (about 1/2 oz.) exerts under these conditions a
centrifugal pull of 15 cwt. on the wheel!




Chapter IV.

THE INTERNAL-COMBUSTION ENGINE.

     The meaning of the term--Action of the internal-combustion
     engine--The motor car--The starting-handle--The engine--The
     carburetter--Ignition of the charge--Advancing the spark--Governing
     the engine--The clutch--The gear-box--The compensating gear--The
     silencer--The brakes--Speed of cars.


THE MEANING OF THE TERM "INTERNAL-COMBUSTION ENGINE."

In the case of a steam-boiler the energy of combustion is transmitted to
water inside an air-tight vessel. The fuel does not actually touch the
"working fluid." In the gas or oil engine the fuel is brought into
contact and mixed with the working fluid, which is air. It combines
suddenly with it in the cylinder, and heat energy is developed so
rapidly that the act is called an explosion. Coal gas, mineral oils,
alcohol, petrol, etc., all contain hydrogen and carbon. If air, which
contributes oxygen, be added to any of these in due proportion, the
mixture becomes highly explosive. On a light being applied, oxygen and
carbon unite, also hydrogen and oxygen, and violent heat is generated,
causing a violent molecular bombardment of the sides of the vessel
containing the mixture. Now, if the mixture be _compressed_ it becomes
hotter and hotter, until a point is reached at which it ignites
spontaneously. Early gas-engines did not compress the charge before
ignition. Alphonse Beau de Rochas, a Frenchman, first thought of making
the piston of the engine squeeze the mixture before ignition; and from
the year 1862, when he proposed this innovation, the success of the
internal-combustion engine may be said to date.

[Illustration]

[Illustration: FIG. 39.--Showing the four strokes that the piston of a
gas-engine makes during one "cycle."]


ACTION OF THE ENGINE.

The gas-engine, the oil-engine, and the motor-car engine are similar in
general principles. The cylinder has, instead of a slide-valve, two, or
sometimes three, "mushroom" valves, which may be described as small and
thick round plates, with bevelled edges, mounted on the ends of short
rods, called stems. These valves open into the cylinder, upwards,
downwards, or horizontally, as the case may be; being pushed in by cams
projecting from a shaft rotated by the engine. For the present we will
confine our attention to the series of operations which causes the
engine to work. This series is called the Beau de Rochas, or Otto,
cycle, and includes four movements of the piston. Reference to Fig. 39
will show exactly what happens in a gas-engine--(1) The piston moves
from left to right, and just as the movement commences valves G (gas)
and A (air) open to admit the explosive mixture. By the time that P has
reached the end of its travel these valves have closed again. (2) The
piston returns to the left, compressing the mixture, which has no way of
escape open to it. At the end of the stroke the charge is ignited by an
incandescent tube I (in motor car and some stationary engines by an
electric spark), and (3) the piston flies out again on the "explosion"
stroke. Before it reaches the limit position, valve E (exhaust) opens,
and (4) the piston flies back under the momentum of the fly-wheel,
driving out the burnt gases through the still open E. The "cycle" is now
complete. There has been suction, compression (including ignition),
combustion, and exhaustion. It is evident that a heavy fly-wheel must be
attached to the crank shaft, because the energy of one stroke (the
explosion) has to serve for the whole cycle; in other words, for two
complete revolutions of the crank. A single-cylinder steam-engine
develops an impulse every half-turn--that is, four times as often. In
order to get a more constant turning effect, motor cars have two, three,
four, six, and even eight cylinders. Four-cylinder engines are at
present the most popular type for powerful cars.


THE MOTOR CAR.

[Illustration: FIG. 40.--Plan of the chassis of a motor car.]

We will now proceed to an examination of the motor car, which, in
addition to mechanical apparatus for the transmission of motion to the
driving-wheels, includes all the fundamental adjuncts of the
internal-combustion engine.[8] Fig. 40 is a bird's-eye view of the
_chassis_ (or "works" and wheels) of a car, from which the body has been
removed. Starting at the left, we have the handle for setting the
engine in motion; the engine (a two-cylinder in this case); the
fly-wheel, inside which is the clutch; the gear-box, containing the cogs
for altering the speed of revolution of the driving-wheels relatively to
that of the engine; the propeller shaft; the silencer, for deadening the
noise of the exhaust; and the bevel-gear, for turning the
driving-wheels. In the particular type of car here considered you will
notice that a "direct," or shaft, drive is used. The shaft has at each
end a flexible, or "universal," joint, which allows the shaft to turn
freely, even though it may not be in a line with the shaft projecting
from the gear-box. It must be remembered that the engine and gear-box
are mounted on the frame, between which and the axles are springs, so
that when the car bumps up and down, the shaft describes part of a
circle, of which the gear-box end is the centre.

An alternative method of driving is by means of chains, which run round
sprocket (cog) wheels on the ends of a shaft crossing the frame just
behind the gear-box, and round larger sprockets attached to the hubs of
the driving-wheels. In such a case the axles of the driving-wheel are
fixed to the springs, and the wheels revolve round them. Where a Cardan
(shaft) drive is used the axles are attached rigidly to the wheels at
one end, and extend, through tubes fixed to the springs, to bevel-wheels
in a central compensating-gear box (of which more presently).

Several parts--the carburetter, tanks, governor, and pump--are not shown
in the general plan. These will be referred to in the more detailed
account that follows.


THE STARTING-HANDLE.

[Illustration: FIG. 41.--The starting-handle.]

Fig. 41 gives the starting-handle in part section. The handle H is
attached to a tube which terminates in a clutch, C. A powerful spring
keeps C normally apart from a second clutch, C^1, keyed to the engine
shaft. When the driver wishes to start the engine he presses the handle
towards the right, brings the clutches together, and turns the handle in
a clockwise direction. As soon as the engine begins to fire, the faces
of the clutches slip over one another.


THE ENGINE.

[Illustration: FIG. 42.--End and cross sections of a two-cylinder
motor.]

We next examine the two-cylinder engine (Fig. 42). Each cylinder is
surrounded by a water-jacket, through which water is circulated by a
pump[9] (Fig. 43). The heat generated by combustion is so great that the
walls of the cylinder would soon become red-hot unless some of the heat
were quickly carried away. The pistons are of "trunk" form--that is,
long enough to act as guides and absorb the oblique thrust of the piston
rods. Three or more piston rings lying in slots (not shown) prevent the
escape of gas past the piston. It is interesting to notice that the
efficiency of an internal-combustion engine depends so largely on the
good fit of these moving parts, that cylinders, pistons, and rings must
be exceedingly true. A good firm will turn out standard parts which are
well within 1/5000 of an inch of perfect truth. It is also a wonderful
testimony to the quality of the materials used that, if properly looked
after, an engine which has made many millions of revolutions, at the
rate of 1,000 to 2,000 per minute, often shows no appreciable signs of
wear. In one particular test an engine was run _continuously for several
months_, and at the end of the trial was in absolutely perfect
condition.

The cranks revolve in an oil-tight case (generally made of aluminium),
and dip in oil, which they splash up into the cylinder to keep the
piston well lubricated. The plate, P P, through a slot in which the
piston rod works, prevents an excess of oil being flung up. Channels are
provided for leading oil into the bearings. The cranks are 180° apart.
While one piston is being driven out by an explosion, the other is
compressing its charge prior to ignition, so that the one action deadens
the other. Therefore two explosions occur in one revolution of the
cranks, and none during the next revolution. If both cranks were in
line, the pistons would move together, giving one explosion each
revolution.

[Illustration: FIG. 43.--Showing how the water which cools the cylinders
is circulated.]

The valve seats, and the inlet and exhaust pipes, are seen in section.
The inlet valve here works automatically, being pulled in by suction;
but on many engines--on all powerful engines--the inlet, like the
exhaust valve, is lifted by a cam, lest it should stick or work
irregularly. Three dotted circles show A, a cog on the crank shaft; B, a
"lay" cog, which transmits motion to C, on a short shaft rotating the
cam that lifts the exhaust valve. C, having twice as many teeth as A,
revolves at half its rate. This ensures that the valve shall be lifted
only once in two revolutions of the crank shaft to which it is geared.
The cogs are timed, or arranged, so that the cam begins to lift the
valve when the piston has made about seven-eighths of its explosion
stroke, and closes the valve at the end of the exhaust stroke.


THE CARBURETTER.

A motor car generally uses petrol as its fuel. Petrol is one of the more
volatile products of petroleum, and has a specific gravity of about
680--that is, volume for volume, its weight is to that of water in the
proportion of 680 to 1,000. It is extremely dangerous, as it gives off
an inflammable gas at ordinary temperatures. Benzine, which we use to
clean clothes, is practically the same as petrol, and should be treated
with equal care. The function of a _carburetter_ is to reduce petrol to
a very fine spray and mix it with a due quantity of air. The device
consists of two main parts (Fig. 44)--the _float chamber_ and the _jet
chamber_. In the former is a contrivance for regulating the petrol
supply. A float--a cork, or air-tight metal box--is arranged to move
freely up and down the stem of a needle-valve, which closes the inlet
from the tank. At the bottom of the chamber are two pivoted levers, W W,
which, when the float rests on them, tip up and lift the valve. Petrol
flows in and raises the float. This allows the valve to sink and cut off
the supply. If the valve is a good fit and the float is of the correct
weight, the petrol will never rise higher than the tip of the jet G.

[Illustration: FIG. 44.--Section of a carburetter.]

The suction of the engine makes petrol spirt through the jet (which has
a very small hole in its end) and atomize itself against a
spraying-cone, A. It then passes to the engine inlet pipe through a
number of openings, after mixing with air entering from below. An extra
air inlet, controllable by the driver, is generally added, unless the
carburetter be of a type which automatically maintains constant
proportions of air and vapour. The jet chamber is often surrounded by a
jacket, through which part of the hot exhaust gases circulate. In cold
weather especially this is a valuable aid to vaporization.

[Illustration: FIG. 45.--Sketch of the electrical ignition arrangements
on a motor car.]


IGNITION OF THE CHARGE.

All petrol-cars now use electrical ignition. There are two main
systems--(1) by an accumulator and induction coil; (2) _magneto
ignition_, by means of a small dynamo driven by the engine. A general
arrangement of the first is shown in Fig. 45. A disc, D, of some
insulating material--fibre or vulcanite--is mounted on the cam, or
half-speed, shaft. Into the circumference is let a piece of brass,
called the contact-piece, through which a screw passes to the cam shaft.
A movable plate, M P, which can be rotated concentrically with D through
part of a circle, carries a "wipe" block at the end of a spring, which
presses it against D. The spring itself is attached to an insulated
plate. When the revolution of D brings the wipe and contact together,
current flows from the accumulator through switch S to the wipe; through
the contact-piece to C; from C to M P and the induction coil; and back
to the accumulator. This is the _primary, or low-tension, circuit_. A
_high-tension_ current is induced by the coil in the _secondary_
circuit, indicated by dotted lines.[10] In this circuit is the
sparking-plug (see Fig. 46), having a central insulated rod in
connection with one terminal of the secondary coil. Between it and a
bent wire projecting from the iron casing of the plug (in contact with
the other terminal of the secondary coil through the metal of the
engine, to which one wire of the circuit is attached) is a small gap,
across which the secondary current leaps when the primary current is
broken by the wipe and contact parting company. The spark is intensely
hot, and suffices to ignite the compressed charge in the cylinder.

[Illustration: FIG. 46.--Section of a sparking-plug.]


ADVANCING THE SPARK.

We will assume that the position of W (in Fig. 45) is such that the
contact touches W at the moment when the piston has just completed the
compression stroke. Now, the actual combustion of the charge occupies
an appreciable time, and with the engine running at high speed the
piston would have travelled some way down the cylinder before the full
force of the explosion was developed. But by raising lever L, the
position of W may be so altered that contact is made slightly _before_
the compression stroke is complete, so that the charge is fairly alight
by the time the piston has altered its direction. This is called
_advancing_ the spark.


GOVERNING THE ENGINE.

There are several methods of controlling the speed of
internal-combustion engines. The operating mechanism in most cases is a
centrifugal ball-governor. When the speed has reached the fixed limit it
either (1) raises the exhaust valve, so that no fresh charges are drawn
in; (2) prevents the opening of the inlet valve; or (3) throttles the
gas supply. The last is now most commonly used on motor cars, in
conjunction with some device for putting it out of action when the
driver wishes to exceed the highest speed that it normally permits.

[Illustration: FIG. 47.--One form of governor used on motor cars.]

A sketch of a neat governor, with regulating attachment, is given in
Fig. 47. The governor shaft is driven from the engine. As the balls, B
B, increase their velocity, they fly away from the shaft and move the
arms, A A, and a sliding tube, C, towards the right. This rocks the
lever R, and allows the valves in the inlet pipe to close and reduce the
supply of air and gas. A wedge, W, which can be raised or lowered by
lever L, intervenes between the end of R and the valve stem. If this
lever be lifted to its highest position, the governing commences at a
lower speed, as the valve then has but a short distance to travel before
closing completely. For high speeds the driver depresses L, forces the
wedge down, and so minimizes the effect of the governor.


THE CLUTCH.

The engine shaft has on its rear end the fly-wheel, which has a broad
and heavy rim, turned to a conical shape inside. Close to this,
revolving loosely on the shaft, is the clutch plate, a heavy disc with a
broad edge so shaped as to fit the inside of a fly-wheel. It is
generally faced with leather. A very strong spring presses the plate
into the fly-wheel, and the resulting friction is sufficient to prevent
any slip. Projections on the rear of the clutch engage with the gear-box
shaft. The driver throws out the clutch by depressing a lever with his
foot. Some clutches dispense with the leather lining. These are termed
_metal to metal_ clutches.


THE GEAR-BOX.

We now come to a very interesting detail of the motor car, the gear-box.
The steam-engine has its speed increased by admitting more steam to the
cylinders. But an explosion engine must be run at a high speed to
develop its full power, and when heavier work has to be done on a hill
it becomes necessary to alter the speed ratio of engine to
driving-wheels. Our illustration (Fig. 48) gives a section of a
gear-box, which will serve as a typical example. It provides three
forward speeds and one reverse. To understand how it works, we must
study the illustration carefully. Pinion 1 is mounted on a hollow shaft
turned by the clutch. Into the hollow shaft projects the end of another
shaft carrying pinions 6 and 4. Pinion 6 slides up and down this shaft,
which is square at this point, but round inside the _loose_ pinion 4.
Pinions 2 and 3 are keyed to a square secondary shaft, and are
respectively always in gear with 1 and 4; but 5 can be slid backwards
and forwards so as to engage or disengage with 6. In the illustration no
gear is "in." If the engine is working, 1 revolves 2, 2 turns 3, and 3
revolves 4 idly on its shaft.

[Illustration: FIG. 48.--The gear-box of a motor car.]

To get the lowest, or "first," speed the driver moves his lever and
slides 5 into gear with 6. The transmission then is: 1 turns 2, 2 turns
5, 5 turns 6, 6 turns the propeller shaft through the universal joint.
For the second speed, 5 and 6 are disengaged, and 6 is moved up the
page, as it were, till projections on it interlock with slots in 4; thus
driving 1, 2, 3, 4, shaft. For the third, or "solid," speed, 6 is pulled
down into connection with 1, and couples the engine shaft direct to the
propeller shaft.

The "reverse" is accomplished by raising a long pinion, 7, which lies in
the gear-box under 5 and 6. The drive then is 1, 2, 5, 7, 6. There being
an odd number of pinions now engaged, the propeller shaft turns in the
reverse direction to that of the engine shaft.

[Illustration: FIG. 49.]


THE COMPENSATING GEAR.

Every axle of a railway train carries a wheel at each end, rigidly
attached to it. When rounding a corner the outside wheel has further to
travel than the other, and consequently one or both wheels must slip.
The curves are made so gentle, however, that the amount of slip is very
small. But with a traction-engine, motor car, or tricycle the case is
different, for all have to describe circles of very small diameter in
proportion to the length of the vehicle. Therefore in every case a
_compensating gear_ is fitted, to allow the wheels to turn at different
speeds, while permitting them both to drive. Fig. 49 is an exaggerated
sketch of the gear. The axles of the moving wheels turn inside tubes
attached to the springs and a central casing (not shown), and terminate
in large bevel-wheels, C and D. Between these are small bevels mounted
on a shaft supported by the driving drum. If the latter be rotated, the
bevels would turn C and D at equal speeds, assuming that both axles
revolve without friction in their bearings. We will suppose that the
drum is turned 50 times a minute. Now, if one wheel be held, the other
will revolve 100 times a minute; or, if one be slowed, the other will
increase its speed by a corresponding amount. The _average_ speed
remains 50. It should be mentioned that drum A has incorporated with it
on the outside a bevel-wheel (not shown) rotated by a smaller bevel on
the end of the propeller shaft.


THE SILENCER.

The petrol-engine, as now used, emits the products of combustion at a
high pressure. If unchecked, they expand violently, and cause a partial
vacuum in the exhaust pipe, into which the air rushes back with such
violence as to cause a loud noise. Devices called _silencers_ are
therefore fitted, to render the escape more gradual, and split it up
among a number of small apertures. The simplest form of silencer is a
cylindrical box, with a number of finely perforated tubes passing from
end to end of it. The exhaust gases pouring into the box maintain a
constant pressure somewhat higher than that of the atmosphere, but as
the gases are escaping from it in a fairly steady stream the noise
becomes a gentle hiss rather than a "pop." There are numerous types of
silencers, but all employ this principle in one form or another.


THE BRAKES.

Every car carries at least two brakes of band pattern--one, usually
worked by a side hand-lever, acting on the axle or hubs of the
driving-wheel; the other, operated by the foot, acting on the
transmission gear (see Fig. 48). The latter brake is generally arranged
to withdraw the clutch simultaneously. Tests have proved that even heavy
cars can be pulled up in astonishingly short distances, considering
their rate of travel. Trials made in the United States with a touring
car and a four-in-hand coach gave 25-1/3 and 70 feet respectively for
the distance in which the speed could be reduced from sixteen miles per
hour to zero.


SPEED OF CARS.

As regards speed, motor cars can rival the fastest express trains, even
on long journeys. In fact, feats performed during the Gordon-Bennett and
other races have equalled railway performances over equal distances.
When we come to record speeds, we find a car, specially built for the
purpose, covering a mile in less than half a minute. A speed of over 120
miles an hour has actually been reached. Engines of 150 h.p. can now be
packed into a vehicle scaling less than 1-1/2 tons. Even on touring cars
are often found engines developing 40 to 60 h.p., which force the car up
steep hills at a pace nothing less than astonishing. In the future the
motor car will revolutionize our modes of life to an extent comparable
to the changes effected by the advent of the steam-engine. Even since
1896, when the "man-with-the-flag" law was abolished in the British
Isles, the motor has reduced distances, opened up country districts, and
generally quickened the pulses of the community in a manner which makes
it hazardous to prophesy how the next generation will live.

_Note._--The author is much indebted to Mr. Wilfrid J. Lineham, M. Inst.
C.E., for several of the illustrations which appear in the above
chapter.


[8] Steam-driven cars are not considered in this chapter, as their
principle is much the same as that of the ordinary locomotive.

[9] On some cars natural circulation is used, the hot water flowing from
the top of the cylinder to the tank, from which it returns, after being
cooled, to the bottom of the cylinder.

[10] For explanation of the induction coil, see p. 122




Chapter V.

ELECTRICAL APPARATUS.

     What is electricity?--Forms of electricity--Magnetism--The
     permanent magnet--Lines of force--Electro-magnets--The electric
     bell--The induction coil--The condenser--Transformation of
     current--Uses of the induction coil.


WHAT IS ELECTRICITY?

Of the ultimate nature of electricity, as of that of heat and light, we
are at present ignorant. But it has been clearly established that all
three phenomena are but manifestations of the energy pervading the
universe. By means of suitable apparatus one form can be converted into
another form. The heat of fuel burnt in a boiler furnace develops
mechanical energy in the engine which the boiler feeds with steam. The
engine revolves a dynamo, and the electric current thereby generated can
be passed through wires to produce mechanical motion, heat, or light. We
must remain content, therefore, with assuming that electricity is energy
or motion transmitted through the ether from molecule to molecule, or
from atom to atom, of matter. Scientific investigation has taught us how
to produce it at will, how to harness it to our uses, and how to measure
it; but not _what_ it is. That question may, perhaps, remain unanswered
till the end of human history. A great difficulty attending the
explanation of electrical action is this--that, except in one or two
cases, no comparison can be established between it and the operation of
gases and fluids. When dealing with the steam-engine, any ordinary
intelligence soon grasps the principles which govern the use of steam in
cylinders or turbines. The diagrams show, it is hoped, quite plainly
"how it works." But electricity is elusive, invisible; and the greatest
authorities cannot say what goes on at the poles of a magnet or on the
surface of an electrified body. Even the existence of "negative" and
"positive" electricity is problematical. However, we see the effects,
and we know that if one thing is done another thing happens; so that we
are at least able to use terms which, while convenient, are not at
present controverted by scientific progress.


FORMS OF ELECTRICITY.

Rub a vulcanite rod and hold one end near some tiny pieces of paper.
They fly to it, stick to it for a time, and then fall off. The rod was
electrified--that is, its surface was affected in such a way as to be in
a state of molecular strain which the contact of the paper fragments
alleviated. By rubbing large surfaces and collecting the electricity in
suitable receivers the strain can be made to relieve itself in the form
of a violent discharge accompanied by a bright flash. This form of
electricity is known as _static_.

Next, place a copper plate and a zinc plate into a jar full of diluted
sulphuric acid. If a wire be attached to them a current of electricity
is said to _flow_ along the wire. We must not, however, imagine that
anything actually moves along inside the wire, as water, steam, or air,
passes through a pipe. Professor Trowbridge says,[11] "No other agency
for transmitting power can be stopped by such slight obstacles as
electricity. A thin sheet of paper placed across a tube conveying
compressed air would be instantly ruptured. It would take a wall of
steel at least an inch thick to stand the pressure of steam which is
driving a 10,000 horse-power engine. A thin layer of dirt beneath the
wheels of an electric car can prevent the current which propels the car
from passing to the rail, and then back to the power-house." There
would, indeed, be a puncture of the paper if the current had a
sufficient voltage, or pressure; yet the fact remains that _current_
electricity can be very easily confined to its conductor by means of
some insulating or nonconducting envelope.


MAGNETISM.

The most familiar form of electricity is that known as magnetism. When a
bar of steel or iron is magnetized, it is supposed that the molecules in
it turn and arrange themselves with all their north-seeking poles
towards the one end of the bar, and their south-seeking poles towards
the other. If the bar is balanced freely on a pivot, it comes to rest
pointing north and south; for, the earth being a huge magnet, its north
pole attracts all the north-seeking poles of the molecules, and its
south poles the south-seeking poles. (The north-_seeking_ pole of a
magnet is marked N., though it is in reality the _south_ pole; for
unlike poles are mutually attractive, and like poles repellent.)

There are two forms of magnet--_permanent_ and _temporary_. If steel is
magnetized, it remains so; but soft iron loses practically all its
magnetism as soon as the cause of magnetization is withdrawn. This is
what we should expect; for steel is more closely compacted than iron,
and the molecules therefore would be able to turn about more easily.[12]
It is fortunate for us that this is so, since on the rapid magnetization
and demagnetization of soft iron depends the action of many of our
electrical mechanisms.


THE PERMANENT MAGNET.

Magnets are either (1) straight, in which case they are called bar
magnets; or (2) of horseshoe form, as in Figs. 50 and 51. By bending the
magnet the two poles are brought close together, and the attraction of
both may be exercised simultaneously on a bar of steel or iron.


LINES OF FORCE.

In Fig. 50 are seen a number of dotted lines. These are called _lines of
magnetic force_. If you lay a sheet of paper on a horseshoe magnet and
sprinkle it with iron dust, you will at once notice how the particles
arrange themselves in curves similar in shape to those shown in the
illustration. It is supposed (it cannot be _proved_) that magnetic force
streams away from the N. pole and describes a circular course through
the air back to the S. pole. The same remark applies to the bar magnet.


ELECTRICAL MAGNETS.

[Illustration: FIG. 50.--Permanent magnet, and the "lines of force"
emanating from it.]

If an insulated wire is wound round and round a steel or iron bar from
end to end, and has its ends connected to the terminals of an electric
battery, current rotates round the bar, and the bar is magnetized. By
increasing the strength and volume of the current, and multiplying the
number of turns of wire, the attractive force of the magnet is
increased. Now disconnect the wires from the battery. If of iron, the
magnet at once loses its attractive force; but if of steel, it retains
it in part. Instead of a simple horseshoe-shaped bar, two shorter bars
riveted into a plate are generally used for electromagnets of this type.
Coils of wire are wound round each bar, and connected so as to form one
continuous whole; but the wire of one coil is wound in the direction
opposite to that of the other. The free end of each goes to a battery
terminal.

In Fig. 51 you will notice that some of the "lines of force" are
deflected through the iron bar A. They pass more easily through iron
than through air; and will choose iron by preference. The attraction
exercised by a magnet on iron may be due to the effort of the lines of
force to shorten their paths. It is evident that the closer A comes to
the poles of the magnet the less will be the distance to be travelled
from one pole to the bar, along it, and back to the other pole.

[Illustration: FIG. 51.--Electro-magnet: A, armature; B, battery.]

Having now considered electricity in three of its forms--static,
current, and rotatory--we will pass to some of its applications.


THE ELECTRIC BELL.

A fit device to begin with is the Electric Bell, which has so largely
replaced wire-pulled bells. These last cause a great deal of trouble
sometimes, since if a wire snaps it may be necessary to take up carpets
and floor-boards to put things right. Their installation is not simple,
for at every corner must be put a crank to alter the direction of the
pull, and the cranks mean increased friction. But when electric wires
have once been properly installed, there should be no need for touching
them for an indefinite period. They can be taken round as many corners
as you wish without losing any of their conductivity, and be placed
wherever is most convenient for examination. One bell may serve a large
number of rooms if an _indicator_ be used to show where the call was
made from, by a card appearing in one of a number of small windows.
Before answering a call, the attendant presses in a button to return the
card to its normal position.

In Fig. 52 we have a diagrammatic view of an electric bell and current.
When the bell-push is pressed in, current flows from the battery to
terminal T^1, round the electro-magnet M, through the pillar P and
flat steel springs S and B, through the platinum-pointed screw, and back
to the battery through the push. The circulation of current magnetizes
M, which attracts the iron armature A attached to the spring S, and
draws the hammer H towards the gong. Just before the stroke occurs, the
spring B leaves the tip of the screw, and the circuit is broken, so that
the magnet no longer attracts. H is carried by its momentum against the
gong, and is withdrawn by the spring, until B once more makes contact,
and the magnet is re-excited. The hammer vibrations recur many times a
second as long as the push is pressed in.

[Illustration: FIG. 52.--Sketch of an electric-bell circuit.]

The electric bell is used for so many purposes that they cannot all be
noted. It plays an especially important part in telephonic installations
to draw the attention of the subscribers, forms an item in automatic
fire and burglar alarms, and is a necessary adjunct of railway
signalling cabins.


THE INDUCTION OR RUHMKORFF COIL.

Reference was made in connection with the electrical ignition of
internal-combustion engines (p. 101) to the _induction coil_. This is a
device for increasing the _voltage_, or pressure, of a current. The
two-cell accumulator carried in a motor car gives a voltage (otherwise
called electro-motive force = E.M.F.) of 4·4 volts. If you attach a wire
to one terminal of the accumulator and brush the loose end rapidly
across the other terminal, you will notice that a bright spark passes
between the wire and the terminal. In reality there are two sparks, one
when they touch, and another when they separate, but they occur so
closely together that the eye cannot separate the two impressions. A
spark of this kind would not be sufficiently hot to ignite a charge in a
motor cylinder, and a spark from the induction coil is therefore used.

[Illustration: FIG. 53.--Sketch of an induction coil.]

We give a sketch of the induction coil in Fig. 53. It consists of a core
of soft iron wires round which is wound a layer of coarse insulated
wire, denoted by the thick line. One end of the winding of this
_primary_ coil is attached to the battery, the other to the base of a
hammer, H, vibrating between the end of the core and a screw, S, passing
through an upright, T, connected with the other terminal of the battery.
The action of the hammer is precisely the same as that of the armature
of an electric bell. Outside the primary coil are wound many turns of a
much finer wire completely insulated from the primary coil. The ends of
this _secondary_ coil are attached to the objects (in the case of a
motor car, the insulated wire of the sparking-plug and a wire projecting
from its outer iron casing) between which a spark has to pass. As soon
as H touches S the circuit is completed. The core becomes a powerful
magnet with external lines of force passing from one pole to the other
over and among the turns of the secondary coil. H is almost
instantaneously attracted by the core, and the break occurs. The lines
of force now (at least so it is supposed) sink into the core, cutting
through the turns of the "secondary," and causing a powerful current to
flow through them. The greater the number of turns, the greater the
number of times the lines of force are cut, and the stronger is the
current. If sufficiently intense, it jumps any gap in the secondary
circuit, heating the intermediate air to a state of incandescence.


THE CONDENSER.

The sudden parting of H and S would produce strong sparking across the
gap between them if it were not for the condenser, which consists of a
number of tinfoil sheets separated by layers of paraffined paper. All
the "odd" sheets are connected with T, all the "even" with T^1. Now,
the more rapid the extinction of magnetism in the core after "break" of
the primary circuit, the more rapidly will the lines of force collapse,
and the more intense will be the induced current in the secondary coil.
The condenser diminishes the period of extinction very greatly, while
lengthening the period of magnetization after the "make" of the primary
current, and so decreasing the strength of the reverse current.


TRANSFORMATION OF CURRENT.

The difference in the voltage of the primary and secondary currents
depends on the length of the windings. If there are 100 turns of wire in
the primary, and 100,000 turns in the secondary, the voltage will be
increased 1,000 times; so that a 4-volt current is "stepped up" to 4,000
volts. In the largest induction coils the secondary winding absorbs
200-300 miles of wire, and the spark given may be anything up to four
feet in length. Such a spark would pierce a glass plate two inches
thick.

It must not be supposed that an induction coil increases the _amount_ of
current given off by a battery. It merely increases its pressure at the
expense of its volume--stores up its energy, as it were, until there is
enough to do what a low-tension flow could not effect. A fair comparison
would be to picture the energy of the low-tension current as the
momentum of a number of small pebbles thrown in succession at a door,
say 100 a minute. If you went on pelting the door for hours you might
make no impression on it, but if you could knead every 100 pebbles into
a single stone, and throw these stones one per minute, you would soon
break the door in.

Any intermittent current can be transformed as regards its intensity.
You may either increase its pressure while decreasing its rate of flow,
or _amperage_; or decrease its pressure and increase its flow. In the
case that we have considered, a continuous battery current is rendered
intermittent by a mechanical contrivance. But if the current comes from
an "alternating" dynamo--that is, is already intermittent--the
contact-breaker is not needed. There will be more to say about
transformation of current in later paragraphs.


USES OF THE INDUCTION COIL.

The induction coil is used--(1.) For passing currents through glass
tubes almost exhausted of air or containing highly rarefied gases. The
luminous effects of these "Geissler" tubes are very beautiful. (2.) For
producing the now famous X or Röntgen rays. These rays accompany the
light rays given off at the negative terminal (cathode) of a vacuum
tube, and are invisible to the eye unless caught on a fluorescent
screen, which reduces their rate of vibration sufficiently for the eye
to be sensitive to them. The Röntgen rays have the peculiar property of
penetrating many substances quite opaque to light, such as metals,
stone, wood, etc., and as a consequence have proved of great use to the
surgeon in localizing or determining the nature of an internal injury.
They also have a deterrent effect upon cancerous growths. (3.) In
wireless telegraphy, to cause powerful electric oscillations in the
ether. (4.) On motor cars, for igniting the cylinder charges. (5.) For
electrical massage of the body.


[11] "What is Electricity?" p. 46.

[12] If a magnetized bar be heated to white heat and tapped with a
hammer it loses its magnetism, because the distance between the
molecules has increased, and the molecules can easily return to their
original positions.




Chapter VI.

THE ELECTRIC TELEGRAPH.

     Needle instruments--Influence of current on the magnetic
     needle--Method of reversing the current--Sounding
     instruments--Telegraphic relays--Recording telegraphs--High-speed
     telegraphy.


Take a small pocket compass and wind several turns of fine insulated
wire round the case, over the top and under the bottom. Now lay the
compass on a table, and turn it about until the coil is on a line with
the needle--in fact, covers it. Next touch the terminals of a battery
with the ends of the wire. The needle at once shifts either to right or
left, and remains in that position as long as the current flows. If you
change the wires over, so reversing the direction of the current, the
needle at once points in the other direction. It is to this conduct on
the part of a magnetic needle when in a "magnetic field" that we owe the
existence of the needle telegraph instrument.


NEEDLE INSTRUMENTS.

[Illustration: FIG. 54.--Sketch of the side elevation of a Wheatstone
needle instrument.]

Probably the best-known needle instrument is the Cooke-Wheatstone,
largely used in signal-boxes and in some post-offices. A vertical
section of it is shown in Fig. 54. It consists of a base, B, and an
upright front, A, to the back of which are attached two hollow coils on
either side of a magnetic needle mounted on the same shaft as a second
dial needle, N, outside the front. The wires W W are connected to the
telegraph line and to the commutator, a device which, when the operator
moves the handle H to right and left, keeps reversing the direction of
the current. The needles on both receiving and transmitting instruments
wag in accordance with the movements of the handle. One or more
movements form an alphabetical letter of the Morse code. Thus, if the
needle points first to left, and then to right, and comes to rest in a
normal position for a moment, the letter A is signified;
right-left-left-left in quick succession = B; right-left-right-left = C,
and so on. Where a marking instrument is used, a dot signifies a "left,"
and a dash a right; and if a "sounder" is employed, the operator judges
by the length of the intervals between the clicks.


INFLUENCE OF CURRENT ON A MAGNETIC NEEDLE.

[Illustration: FIGS. 55, 56.--The coils of a needle instrument. The
arrows show the direction taken by the current.]

Figs. 55 and 56 are two views of the coils and magnetic needle of the
Wheatstone instrument as they appear from behind. In Fig. 55 the current
enters the left-hand coil from the left, and travels round and round it
in a clockwise direction to the other end, whence it passes to the other
coil and away to the battery. Now, a coil through which a current passes
becomes a magnet. Its polarity depends on the direction in which the
current flows. Suppose that you are looking through the coil, and that
the current enters it from your end. If the wire is wound in a clockwise
direction, the S. pole will be nearest you; if in an anti-clockwise
direction, the N. pole. In Fig. 55 the N. poles are at the right end of
the coils, the S. poles at the left end; so the N. pole of the needle is
attracted to the right, and the S. pole to the left. When the current is
reversed, as in Fig. 56, the needle moves over. If no current passes, it
remains vertical.


METHOD OF REVERSING THE CURRENT.

[Illustration: FIG. 57.--General arrangement of needle-instrument
circuit. The shaded plates on the left (B and R) are in contact.]

A simple method of changing the direction of the current in a
two-instrument circuit is shown diagrammatically in Fig. 57. The
_principle_ is used in the Wheatstone needle instrument. The battery
terminals at each station are attached to two brass plates, A B, A^1
B^1. Crossing these at right angles (under A A^1 and over B B^1)
are the flat brass springs, L R, L^1 R^1, having buttons at their
lower ends, and fixed at their upper ends to baseboards. When at rest
they all press upwards against the plates A and A^1 respectively. R
and L^1 are connected with the line circuit, in which are the coils of
dials 1 and 2, one at each station. L and R^1 are connected with the
earth-plates E E^1. An operator at station 1 depresses R so as to
touch B. Current now flows from the battery to B, thence through R to
the line circuit, round the coils of both dials through L^1 A^1 and
R to earth-plate E^1, through the earth to E, and then back to the
battery through L and A. The needles assume the position shown. To
reverse the current the operator allows R to rise into contact with A,
and depresses L to touch B. The course can be traced out easily.

In the Wheatstone "drop-handle" instrument (Fig. 54) the commutator may
be described as an insulated core on which are two short lengths of
brass tubing. One of these has rubbing against it a spring connected
with the + terminal of the battery; the other has similar communication
with the - terminal. Projecting from each tube is a spike, and rising
from the baseboard are four upright brass strips not quite touching the
commutator. Those on one side lead to the line circuit, those on the
other to the earth-plate. When the handle is turned one way, the spikes
touch the forward line strip and the rear earth strip, and _vice versâ_
when moved in the opposite direction.


SOUNDING INSTRUMENTS.

Sometimes little brass strips are attached to the dial plate of a needle
instrument for the needle to strike against. As these give different
notes, the operator can comprehend the message by ear alone. But the
most widely used sounding instrument is the Morse sounder, named after
its inventor. For this a reversible current is not needed. The receiver
is merely an electro-magnet (connected with the line circuit and an
earth-plate) which, when a current passes, attracts a little iron bar
attached to the middle of a pivoted lever. The free end of the lever
works between two stops. Every time the circuit is closed by the
transmitting key at the sending station the lever flies down against the
lower stop, to rise again when the circuit is broken. The duration of
its stay decides whether a "long" or "short" is meant.


TELEGRAPHIC RELAYS.

[Illustration: FIG. 58.--Section of a telegraph wire insulator on its
arm. The shaded circle is the line wire, the two blank circles indicate
the wire which ties the line wire to the insulator.]

When an electric current has travelled for a long distance through a
wire its strength is much reduced on account of the resistance of the
wire, and may be insufficient to cause the electro-magnet of the sounder
to move the heavy lever. Instead, therefore, of the current acting
directly on the sounder magnet, it is used to energize a small magnet,
or _relay_, which pulls down a light bar and closes a second "local"
circuit--that is, one at the receiver end--worked by a separate battery,
which has sufficient power to operate the sounder.


RECORDING TELEGRAPHS.

By attaching a small wheel to the end of a Morse-sounder lever, by
arranging an ink-well for the wheel to dip into when the end falls, and
by moving a paper ribbon slowly along for the wheel to press against
when it rises, a self-recording Morse inker is produced. The
ribbon-feeding apparatus is set in motion automatically by the current,
and continues to pull the ribbon along until the message is completed.

The Hughes type-printer covers a sheet of paper with printed characters
in bold Roman type. The transmitter has a keyboard, on which are marked
letters, signs, and numbers; also a type-wheel, with the characters on
its circumference, rotated by electricity. The receiver contains
mechanisms for rotating another type-wheel synchronously--that is, in
time--with the first; for shifting the wheel across the paper; for
pressing the paper against the wheel; and for moving the paper when a
fresh line is needed. These are too complicated to be described here in
detail. By means of relays one transmitter may be made to work five
hundred receivers. In London a single operator, controlling a keyboard
in the central dispatching office, causes typewritten messages to spell
themselves out simultaneously in machines distributed all over the
metropolis.

The tape machine resembles that just described in many details. The main
difference is that it prints on a continuous ribbon instead of on
sheets.

Automatic electric printers of some kind or other are to be found in
the vestibules of all the principal hotels and clubs of our large
cities, and in the offices of bankers, stockbrokers, and newspaper
editors. In London alone over 500 million words are printed by the
receivers in a year.


HIGH-SPEED TELEGRAPHY.

At certain seasons, or when important political events are taking place,
the telegraph service would become congested with news were there not
some means of transmitting messages at a much greater speed than is
possible by hand signalling. Fifty words a minute is about the limit
speed that a good operator can maintain. By means of Wheatstone's
_automatic transmitter_ the rate can be increased to 400 words per
minute. Paper ribbons are punched in special machines by a number of
clerks with a series of holes which by their position indicate a dot or
a dash. The ribbons are passed through a special transmitter, over
little electric brushes, which make contact through the holes with
surfaces connected to the line circuit. At the receiver end the message
is printed by a Morse inker.

It has been found possible to send several messages simultaneously over
a single line. To effect this a _distributer_ is used to put a number of
transmitters at one end of the line in communication with an equal
number of receivers at the other end, fed by a second distributer
keeping perfect time with the first. Instead of a signal coming as a
whole to any one instrument it arrives in little bits, but these follow
one another so closely as to be practically continuous. By working a
number of automatic transmitters through a distributer, a thousand words
or more per minute are easily dispatched over a single wire.

The Pollak Virag system employs a punched ribbon, and the receiver
traces out the message in alphabetical characters on a moving strip of
sensitized photographic paper. A mirror attached to a vibrating
diaphragm reflects light from a lamp on to the strip, which is
automatically developed and fixed in chemical baths. The method of
moving the mirror so as to make the rays trace out words is extremely
ingenious. Messages have been transmitted by this system at the rate of
180,000 words per hour.




Chapter VII.

WIRELESS TELEGRAPHY.

     The transmitting apparatus--The receiving apparatus--Syntonic
     transmission--The advance of wireless telegraphy.


In our last chapter we reviewed briefly some systems of sending
telegraphic messages from one point of the earth's surface to another
through a circuit consisting partly of an insulated wire and partly of
the earth itself. The metallic portion of a long circuit, especially if
it be a submarine cable, is costly to install, so that in quite the
early days of telegraphy efforts were made to use the ether in the place
of wire as one conductor.

When a hammer strikes an anvil the air around is violently disturbed.
This disturbance spreads through the molecules of the air in much the
same way as ripples spread from the splash of a stone thrown into a
pond. When the sound waves reach the ear they agitate the tympanum, or
drum membrane, and we "hear a noise." The hammer is here the
transmitter, the air the conductor, the ear the receiver.

In wireless telegraphy we use the ether as the conductor of electrical
disturbances.[13] Marconi, Slaby, Branly, Lodge, De Forest, Popoff, and
others have invented apparatus for causing disturbances of the requisite
kind, and for detecting their presence.

The main features of a wireless telegraphy outfit are shown in Figs. 59
and 61.


THE TRANSMITTER APPARATUS.

We will first consider the transmitting outfit (Fig. 59). It includes a
battery, dispatching key, and an induction coil having its secondary
circuit terminals connected with two wires, the one leading to an
earth-plate, the other carried aloft on poles or suspended from a kite.
In the large station at Poldhu, Cornwall, for transatlantic signalling,
there are special wooden towers 215 feet high, between which the aërial
wires hang. At their upper and lower ends respectively the earth and
aërial wires terminate in brass balls separated by a gap. When the
operator depresses the key the induction coil charges these balls and
the wires attached thereto with high-tension electricity. As soon as the
quantity collected exceeds the resistance of the air-gap, a discharge
takes place between the balls, and the ether round the aërial wire is
violently disturbed, and waves of electrical energy are propagated
through it. The rapidity with which the discharges follow one another,
and their travelling power, depends on the strength of the induction
coil, the length of the air-gap, and the capacity of the wires.[14]

[Illustration: FIG. 59.--Sketch of the transmitter of a wireless
telegraphy outfit.]

[Illustration: FIG. 60.--A Marconi coherer.]


RECEIVING APPARATUS.

The human body is quite insensitive to these etheric waves. We cannot
feel, hear, or see them. But at the receiving station there is what may
be called an "electric eye." Technically it is named a _coherer_. A
Marconi coherer is seen in Fig. 60. Inside a small glass tube exhausted
of air are two silver plugs, P P, carrying terminals, T T, projecting
through the glass at both ends. A small gap separates the plugs at the
centre, and this gap is partly filled with nickel-silver powder. If the
terminals of the coherer are attached to those of a battery, practically
no current will pass under ordinary conditions, as the particles of
nickel-silver touch each other very lightly and make a "bad contact."
But if the coherer is also attached to wires leading into the earth and
air, and ether waves strike those wires, at every impact the particles
will cohere--that is, pack tightly together--and allow battery current
to pass. The property of cohesion of small conductive bodies when
influenced by Hertzian waves was first noticed in 1874 by Professor D.E.
Hughes while experimenting with a telephone.

[Illustration: FIG. 61.--Sketch of the receiving apparatus in a
wireless telegraphy outfit.]

We are now in a position to examine the apparatus of which a coherer
forms part (Fig. 61). First, we notice the aërial and earth wires, to
which are attached other wires from battery A. This battery circuit
passes round the relay magnet R and through two choking coils, whose
function is to prevent the Hertzian waves entering the battery. The
relay, when energized, brings contact D against E and closes the circuit
of battery B, which is much more powerful than battery A, and operates
the magnet M as well as the _tapper_, which is practically an electric
bell minus the gong. (The tapper circuit is indicated by the dotted
lines.)

We will suppose the transmitter of a distant station to be at work. The
electric waves strike the aërial wire of the receiving station, and
cause the coherer to cohere and pass current. The relay is closed, and
both tapper and Morse inker begin to work. The tapper keeps striking the
coherer and shakes the particles loose after every cohesion. If this
were not done the current of A would pass continuously after cohesion
had once taken place. When the key of the transmitter is pressed down,
the waves follow one another very quickly, and the acquired conductivity
of the coherer is only momentarily destroyed by the tap of the hammer.
During the impression of a dot by the Morse inker, contact is made and
broken repeatedly; but as the armature of the inker is heavy and slow to
move it does not vibrate in time with the relay and tapper. Therefore
the Morse instrument reproduces in dots and dashes the short and long
depressions of the key at the transmitting station, while the tapper
works rapidly in time with the relay. The Morse inker is shown
diagrammatically. While current passes through M the armature is pulled
towards it, the end P, carrying an inked wheel, rises, and a mark is
made on the tape W, which is moved continuously being drawn forward off
reel R by the clockwork--or electrically-driven rollers R^1 R^2.


SYNTONIC TRANSMISSION.

If a number of transmitting stations are sending out messages
simultaneously, a jumble of signals would affect all the receivers
round, unless some method were employed for rendering a receiver
sensitive only to the waves intended to influence it. Also, if
distinction were impossible, even with one transmitter in action its
message might go to undesired stations.

There are various ways of "tuning" receivers and transmitters, but the
principle underlying them all is analogous to that of mechanical
vibration. If a weight is suspended from the end of a spiral spring, and
given an upward blow, it bobs up and down a certain number of times per
minute, every movement from start to finish having exactly the same
duration as the rest. The resistance of the air and the internal
friction of the spring gradually lessen the amplitude of the movements,
and the weight finally comes to rest. Suppose that the weight scales 30
lbs., and that it naturally bobs twenty times a minute. If you now take
a feather and give it a push every three seconds you can coax it into
vigorous motion, assuming that every push catches it exactly on the
rebound. The same effect would be produced more slowly if 6 or 9 second
intervals were substituted. But if you strike it at 4, 5, or 7 second
intervals it will gradually cease to oscillate, as the effect of one
blow neutralizes that of another. The same phenomenon is witnessed when
two tuning-forks of equal pitch are mounted near one another, and one is
struck. The other soon picks up the note. But a fork of unequal pitch
would remain dumb.

Now, every electrical circuit has a "natural period of oscillation" in
which its electric charge vibrates. It is found possible to "tune," or
"syntonize," the aërial rod or wire of a receiving station with a
transmitter. A vertical wire about 200 feet in length, says Professor
J.A. Fleming,[15] has a natural time period of electrical oscillation of
about one-millionth of a second. Therefore if waves strike this wire a
million times a second they will reinforce one another and influence the
coherer; whereas a less or greater frequency will leave it practically
unaffected. By adjusting the receiving circuit to the transmitter, or
_vice versâ_, selective wireless telegraphy becomes possible.


ADVANCE OF WIRELESS TELEGRAPHY.

The history of wireless telegraphy may be summed up as follows:--

1842.--Professor Morse sent aërial messages across the Susquehanna
River. A line containing a battery and transmitter was carried on posts
along one bank and "earthed" in the river at each end. On the other bank
was a second wire attached to a receiver and similarly earthed. Whenever
contact was made and broken on the battery side, the receiver on the
other was affected. Distance about 1 mile.

1859.--James Bowman Lindsay transmitted messages across the Tay at
Glencarse in a somewhat similar way. Distance about 1/2 mile.

1885.--Sir William Preece signalled from Lavernock Point, near Cardiff,
to Steep Holm, an island in the Bristol Channel. Distance about 5-1/2
miles.

In all these electrical _induction_ of current was employed.

1886.--Hertzian waves discovered.

1895.--Professor A. Popoff sent Hertzian wave messages over a distance
of 3 miles.

1897.--Marconi signalled from the Needles Hotel, Isle of Wight, to
Swanage; 17-1/2 miles.

1901.--Messages sent at sea for 380 miles.

1901, Dec. 17.--Messages transmitted from Poldhu, Cornwall, to Hospital
Point, Newfoundland; 2,099 miles.

Mr. Marconi has so perfected tuning devices that his transatlantic
messages do not affect receivers placed on board ships crossing the
ocean, unless they are purposely tuned. Atlantic liners now publish
daily small newspapers containing the latest news, flashed through space
from land stations. In the United States the De Forest and Fessenden
systems are being rapidly extended to embrace the most out-of-the-way
districts. Every navy of importance has adopted wireless telegraphy,
which, as was proved during the Russo-Japanese War, can be of the
greatest help in directing operations.


[13] Named after their first discoverer, Dr. Hertz of Carlsruhe,
"Hertzian waves."

[14] For long-distance transmission powerful dynamos take the place of
the induction coil and battery.

[15] "Technics," vol. ii. p. 566.




Chapter VIII.

THE TELEPHONE.

     The Bell telephone--The Edison transmitter--The granular carbon
     transmitter--General arrangement of a telephone
     circuit--Double-line circuits--Telephone exchanges--Submarine
     telephony.


For the purposes of everyday life the telephone is even more useful than
the telegraph. Telephones now connect one room of a building with
another, house with house, town with town, country with country. An
infinitely greater number of words pass over the telephonic circuits of
the world in a year than are transmitted by telegraph operators. The
telephone has become an important adjunct to the transaction of business
of all sorts. Its wires penetrate everywhere. Without moving from his
desk, the London citizen may hold easy converse with a Parisian, a New
Yorker with a dweller in Chicago.

Wonderful as the transmission of signals over great distances is, the
transmission of human speech so clearly that individual voices may be
distinguished hundreds of miles away is even more so. Yet the instrument
which works the miracle is essentially simple in its principles.


THE BELL TELEPHONE.

[Illustration: FIG. 62.--Section of a Bell telephone.]

The first telephone that came into general use was that of Bell, shown
in Fig. 62. In a central hole of an ebonite casing is fixed a permanent
magnet, M. The casing expands at one end to accommodate a coil of
insulated wire wound about one extremity of a magnet. The coil ends are
attached to wires passing through small channels to terminals at the
rear. A circular diaphragm, D, of very thin iron plate, clamped between
the concave mouthpiece and the casing, almost touches the end of the
magnet.

We will suppose that two Bell telephones, A and B, are connected up by
wires, so that the wires and the coils form a complete circuit. Words
are spoken into A. The air vibrations, passing through the central hole
in the cover, make the diaphragm vibrate towards and away from the
magnet. The distances through which the diaphragm moves have been
measured, and found not to exceed in some cases more than 1/10,000,000
of an inch! Its movements distort the shape of the "lines of force" (see
p. 118) emanating from the magnet, and these, cutting through the turns
of the coil, induce a current in the line circuit. As the diaphragm
approaches the magnet a circuit is sent in one direction; as it leaves
it, in the other. Consequently speech produces rapidly alternating
currents in the circuit, their duration and intensity depending on the
nature of the sound.

Now consider telephone B. The currents passing through its coil increase
or diminish the magnetism of the magnet, and cause it to attract its
diaphragm with varying force. The vibration of the diaphragm disturbs
the air in exact accordance with the vibrations of A's diaphragm, and
speech is reproduced.


THE EDISON TRANSMITTER.

The Bell telephone may be used both as a transmitter and a receiver, and
the permanent magnetism of the cores renders it independent of an
electric battery. But currents generated by it are so minute that they
cannot overcome the resistance of a long circuit; therefore a battery is
now always used, and with it a special device as transmitter.

If in a circuit containing a telephone and a battery there be a loose
contact, and this be shaken, the varying resistance of the contact will
cause electrical currents of varying force to pass through the circuit.
Edison introduced the first successful _microphone_ transmitter, in
which a small platinum disc connected to the diaphragm pressed with
varying force against a disc of carbon, each disc forming part of the
circuit. Vibrations of the diaphragm caused current to flow in a series
of rapid pulsations.

[Illustration: FIG. 63.--Section of a granular carbon transmitter.]


THE GRANULAR CARBON TRANSMITTER.

In Fig. 63 we have a section of a microphone transmitter now very widely
used. It was invented, in its original form, by an English clergyman
named Hunnings. Resting in a central cavity of an ebonite seating is a
carbon block, C, with a face moulded into a number of pyramidal
projections, P P. The space between C and a carbon diaphragm, D, is
packed with carbon granules, G G. C has direct contact with line
terminal T, which screws into it; D with T^1 through the brass casing,
screw S, and a small plate at the back of the transmitter. Voice
vibrations compress G G, and allow current to pass more freely from D
to C. This form of microphone is very delicate, and unequalled for
long-distance transmission.

[Illustration: FIG. 64.--A diagrammatic representation of a telephonic
circuit.]


GENERAL ARRANGEMENT OF A TELEPHONE CIRCUIT.

In many forms of subscriber's instruments both receiver and transmitter
are mounted on a single handle in such a way as to be conveniently
placed for ear and mouth. For the sake of clearness the diagrammatic
sketch of a complete installation (Fig. 64) shows them separated. The
transmitters, it will be noticed, are located in battery circuits,
including the primary windings P P_2 of induction coils. The
transmitters are in the line circuit, which includes the secondary
windings S S_2 of the coils.

We will assume that the transmitters are, in the first instance, both
hung on the hooks of the metallic switches, which their weight depresses
to the position indicated by the dotted lines. The handle of the
magneto-generator at the left-end station is turned, and current passes
through the closed circuit:--Line A, E B_2, contact 10, the switch 9;
line B, 4, the other switch, contact 5, and E B. Both bells ring. Both
parties now lift their receivers from the switch hooks. The switches
rise against contacts 1, 2, 3 and 6, 7, 8 respectively. Both primary and
both secondary circuits are now completed, while the bells are
disconnected from the line wires. The pulsations set up by transmitter T
in primary coil P are magnified by secondary coil S for transmission
through the line circuit, and affect both receivers. The same thing
happens when T_2 is used. At the end of the conversation the receivers
are hung on their hooks again, and the bell circuit is remade, ready for
the next call.

[Illustration: A TELEPHONE EXCHANGE.]


DOUBLE-LINE CIRCUITS.

The currents used in telephones pulsate very rapidly, but are very
feeble. Electric disturbances caused by the proximity of telegraph or
tram wires would much interfere with them if the earth were used for the
return circuit. It has been found that a complete metallic circuit (two
wires) is practically free from interference, though where a number of
wires are hung on the same poles, speech-sounds may be faintly induced
in one circuit from another. This defect is, however, minimized by
crossing the wires about among themselves, so that any one line does not
pass round the corresponding insulator on every pole.


TELEPHONE EXCHANGES.

In a district where a number of telephones are used the subscribers are
put into connection with one another through an "exchange," to which all
the wires lead. One wire of each subscriber runs to a common "earth;"
the other terminates at a switchboard presided over by an operator. In
an exchange used by many subscribers the terminals are distributed over
a number of switchboards, each containing 80 to 100 terminals, and
attended to by an operator, usually a girl.

When a subscriber wishes to be connected to another subscriber, he
either turns the handle of a magneto generator, which causes a shutter
to fall and expose his number at the exchange, or simply depresses a key
which works a relay at the exchange and lights a tiny electric lamp. The
operator, seeing the signal, connects her telephone with the
subscriber's circuit and asks the number wanted. This given, she rings
up the other subscriber, and connects the two circuits by means of an
insulated wire cord having a spike at each end to fit the "jack" sockets
of the switchboard terminals. The two subscribers are now in
communication.

[Illustration: FIG. 65.--The headdress of an operator at a telephone
exchange. The receiver is fastened over one ear, and the transmitter to
the chest.]

If a number on switchboard A calls for a number on switchboard C, the
operator at A connects her subscriber by a jack cord to a trunk line
running to C, where the operator similarly connects the trunk line with
the number asked for, after ringing up the subscriber. The central
exchange of one town is connected with that of another by one or more
trunk lines, so that a subscriber may speak through an indefinite number
of exchanges. So perfect is the modern telephone that the writer
remembers on one occasion hearing the door-bell ring in a house more
than a hundred miles away, with which he was at the moment in telephonic
connection, though three exchanges were in the circuit.


SUBMARINE TELEPHONY.

Though telegraphic messages are transmitted easily through thousands of
miles of cable,[16] submarine telephony is at present restricted to
comparatively short distances. When a current passes through a cable,
electricity of opposite polarity induced on the outside of the cable
damps the vibration in the conductor. In the Atlantic cable, strong
currents of electricity are poured periodically into one end, and though
much enfeebled when they reach the other they are sufficiently strong to
work a very delicate "mirror galvanometer" (invented by Lord Kelvin),
which moves a reflected ray up and down a screen, the direction of the
movements indicating a dot or a dash. Reversible currents are used in
transmarine telegraphy. The galvanometer is affected like the coils and
small magnet in Wheatstone's needle instrument (p. 128).

Telephonic currents are too feeble to penetrate many miles of cable.
There is telephonic communication between England and France, and
England and Ireland. But transatlantic telephony is still a thing of the
future. It is hoped, however, that by inserting induction coils at
intervals along the cables the currents may be "stepped up" from point
to point, and so get across. Turning to Fig. 64, we may suppose S to be
on shore at the English end, and S_2 to be the _primary_ winding of an
induction coil a hundred miles away in the sea, which magnifies the
enfeebled vibrations for a journey to S_3, where they are again
revived; and so on, till the New World is reached. The difficulty is to
devise induction coils of great power though of small size. Yet science
advances nowadays so fast that we may live to hear words spoken at the
Antipodes.


[16] In 1896 the late Li Hung Chang sent a cablegram from China to
England (12,608 miles), and received a reply, in _seven minutes_.




Chapter IX.

DYNAMOS AND ELECTRIC MOTORS.

     A simple dynamo--Continuous-current dynamos--Multipolar
     dynamos--Exciting the field magnets--Alternating current
     dynamos--The transmission of power--The electric motor--Electric
     lighting--The incandescent lamp--Arc lamps--"Series" and "parallel"
     arrangement of lamps--Current for electric lamps--Electroplating.


In previous chapters we have incidentally referred to the conversion of
mechanical work into electrical energy. In this we shall examine how it
is done--how the silently spinning dynamo develops power, and why the
motor spins when current is passed through it.

We must begin by returning to our first electrical diagram (Fig. 50),
and calling to mind the invisible "lines of force" which permeate the
ether in the immediate neighbourhood of a magnet's poles, called the
_magnetic field_ of the magnet.

Many years ago (1831) the great Michael Faraday discovered that if a
loop of wire were moved up and down between the poles of an
electro-magnet (Fig. 66) a current was induced in the loop, its
direction depending upon that in which the loop was moved. The energy
required to cut the lines of force passed in some mysterious way into
the wire. Why this is so we cannot say, but, taking advantage of the
fact, electricians have gradually developed the enormous machines which
now send vehicles spinning over metal tracks, light our streets and
houses, and supply energy to innumerable factories.

[Illustration: FIG. 66.]

The strength of the current induced in a circuit cutting the lines of
force of a magnet is called its pressure, voltage, or electro-motive
force (expressed shortly E.M.F.). It may be compared with the
pounds-to-the-square-inch of steam. In order to produce an E.M.F. of one
volt it is calculated that 100,000,000 lines of force must be cut every
second.

The voltage depends on three things:--(1.) The _strength_ of the magnet:
the stronger it is, the greater the number of lines of force coming from
it. (2.) The _length_ of the conductor cutting the lines of force: the
longer it is, the more lines it will cut. (3.) The _speed_ at which the
conductor moves: the faster it travels, the more lines it will cut in a
given time. It follows that a powerful dynamo, or mechanical producer of
current, must have strong magnets and a long conductor; and the latter
must be moved at a high speed across the lines of force.


A SIMPLE DYNAMO.

In Fig. 67 we have the simplest possible form of dynamo--a single turn
of wire, _w x y z_, mounted on a spindle, and having one end attached to
an insulated ring C, the other to an insulated ring C^1. Two small
brushes, B B^1, of wire gauze or carbon, rubbing continuously against
these collecting rings, connect them with a wire which completes the
circuit. The armature, as the revolving coil is called, is mounted
between the poles of a magnet, where the lines of force are thickest.
These lines are _supposed_ to stream from the N. to the S. pole.

In Fig. 67 the armature has reached a position in which _y z_ and _w x_
are cutting no, or very few, lines of force, as they move practically
parallel to the lines. This is called the _zero_ position.

[Illustration: FIG. 67.]

[Illustration: FIG. 68.]

In Fig. 68 the armature, moving at right angles to the lines of force,
cuts a maximum number in a given time, and the current induced in the
coil is therefore now most intense. Here we must stop a moment to
consider how to decide in which direction the current flows. The
armature is revolving in a clockwise direction, and _y z_, therefore, is
moving downwards. Now, suppose that you rest your _left_ hand on the N.
pole of the magnet so that the arm lies in a line with the magnet. Point
your forefinger towards the S. pole. It will indicate the _direction of
the lines of force_. Bend your other three fingers downwards over the
edge of the N. pole. They will indicate the _direction in which the
conductor is moving_ across the magnetic field. Stick out the thumb at
right angles to the forefinger. It points in the direction in which the
_induced_ current is moving through the nearer half of the coil.
Therefore lines of force, conductor, and induced current travel in
planes which, like the top and two adjacent sides of a box, are at right
angles to one another.

While current travels from _z_ to _y_--that is, _from_ the ring C^1 to
_y_--it also travels from _x_ to _w_, because _w x_ rises while _y z_
descends. So that a current circulates through the coil and the exterior
part of the circuit, including the lamp. After _z y_ has passed the
lowest possible point of the circle it begins to ascend, _w x_ to
descend. The direction of the current is therefore reversed; and as the
change is repeated every half-revolution this form of dynamo is called
an _alternator_ or creator of alternating currents. A well-known type of
alternator is the magneto machine which sends shocks through any one who
completes the external circuit by holding the brass handles connected by
wires to the brushes. The faster the handle of the machine is turned the
more frequent is the alternation, and the stronger the current.

[Illustration: FIG. 69.]


CONTINUOUS-CURRENT DYNAMOS.

An alternating current is not so convenient for some purposes as a
continuous current. It is therefore sometimes desirable (even necessary)
to convert the alternating into a uni-directional or continuous current.
How this is done is shown in Figs. 69 and 70. In place of the two
collecting rings C C^1, we now have a single ring split longitudinally
into two portions, one of which is connected to each end of the coil _w
x y z_. In Fig. 69 brush B has just passed the gap on to segment C,
brush B^1 on to segment C^1. For half a revolution these remain
respectively in contact; then, just as _y z_ begins to rise and _w x_ to
descend, the brushes cross the gaps again and exchange segments, so that
the current is perpetually flowing one way through the circuit. The
effect of the commutator[17] is, in fact, equivalent to transposing the
brushes of the collecting rings of the alternator every time the coil
reaches a zero position.

Figs. 71 and 72 give end views in section of the coil and the
commutator, with the coil in the position of minimum and maximum
efficiency. The arrow denotes the direction of movement; the double
dotted lines the commutator end of the revolving coil.

[Illustration: FIG. 70.]


PRACTICAL CONTINUOUS-CURRENT DYNAMOS.

The electrical output of our simple dynamo would be increased if,
instead of a single turn of wire, we used a coil of many turns. A
further improvement would result from mounting on the shaft, inside the
coil, a core or drum of iron, to entice the lines of force within reach
of the revolving coil. It is evident that any lines which pass through
the air outside the circle described by the coil cannot be cut, and are
wasted.

[Illustration: FIG. 71.]

[Illustration: FIG. 72.]

The core is not a solid mass of iron, but built up of a number of very
thin iron discs threaded on the shaft and insulated from one another to
prevent electric eddies, which would interfere with the induced current
in the conductor.[18] Sometimes there are openings through the core from
end to end to ventilate and cool it.

[Illustration: FIG. 73.]

We have already noticed that in the case of a single coil the current
rises and falls in a series of pulsations. Such a form of armature would
be unsuitable for large dynamos, which accordingly have a number of
coils wound over their drums, at equal distances round the
circumference, and a commutator divided into an equal number of
segments. The subject of drum winding is too complicated for brief
treatment, and we must therefore be content with noticing that the coils
are so connected to their respective commutator segments and to one
another that they mutually assist one another. A glance at Fig. 73 will
help to explain this. Here we have in section a number of conductors on
the right of the drum (marked with a cross to show that current is
moving, as it were, into the page), connected with conductors on the
left (marked with a dot to signify current coming out of the page). If
the "crossed" and "dotted" conductors were respectively the "up" and
"down" turns of a single coil terminating in a simple split commutator
(Fig. 69), when the coil had been revolved through an angle of 90° some
of the up turns would be ascending and some descending, so that
conflicting currents would arise. Yet we want to utilize the whole
surface of the drum; and by winding a number of coils in the manner
hinted at, each coil, as it passes the zero point, top or bottom, at
once generates a current in the desired direction and reinforces that in
all the other turns of its own and of other coils on the same side of a
line drawn vertically through the centre. There is thus practically no
fluctuation in the pressure of the current generated.

The action of single and multiple coil windings may be compared to that
of single and multiple pumps. Water is ejected by a single pump in
gulps; whereas the flow from a pipe fed by several pumps arranged to
deliver consecutively is much more constant.


MULTIPOLAR DYNAMOS.

Hitherto we have considered the magnetic field produced by one bi-polar
magnet only. Large dynamos have four, six, eight, or more field magnets
set inside a casing, from which their cores project towards the armature
so as almost to touch it (Fig. 74). The magnet coils are wound to give
N. and S. poles alternately at their armature ends round the field; and
the lines of force from each N. pole stream each way to the two adjacent
S. poles across the path of the armature coils. In dynamos of this kind
several pairs of collecting brushes pick current off the commutator at
equidistant points on its circumference.

[Illustration: FIG. 74.--A Holmes continuous current dynamo: A,
armature; C, commutator; M, field magnets.]


EXCITING THE FIELD MAGNETS.

Until current passes through the field magnet coils, no magnetic field
can be created. How are the coils supplied with current? A dynamo,
starting for the first time, is excited by a current from an outside
source; but when it has once begun to generate current it feeds its
magnets itself, and ever afterwards will be self-exciting,[19] owing to
the residual magnetism left in the magnet cores.

[Illustration: FIG. 75.--Partly finished commutator.]

Look carefully at Figs. 77 and 78. In the first of these you will
observe that part of the wire forming the external circuit is wound
round the arms of the field magnet. This is called a _series_ winding.
In this case _all_ the current generated helps to excite the dynamo. At
the start the residual magnetism of the magnet cores gives a weak field.
The armature coils cut this and pass a current through the circuit. The
magnets are further excited, and the field becomes stronger; and so on
till the dynamo is developing full power. Series winding is used where
the current in the external circuit is required to be very constant.

[Illustration: FIG. 76.--The brushes of a Holmes dynamo.]

Fig. 78 shows another method of winding--the _shunt_. Most of the
current generated passes through the external circuit 2, 2; but a part
is switched through a separate winding for the magnets, denoted by the
fine wire 1, 1. Here the strength of the magnetism does not vary
directly with the current, as only a small part of the current serves
the magnets. The shunt winding is therefore used where the voltage (or
pressure) must be constant.

[Illustration: FIG. 77.--Sketch showing a "series" winding.]

[Illustration: FIG. 78.--"Shunt" winding.]

A third method is a combination of the two already named. A winding of
fine wire passes from brush to brush round the magnets; and there is
also a series winding as in Fig. 77. This compound method is adapted
more especially for electric traction.


ALTERNATING DYNAMOS.

These have their field magnets excited by a separate continuous current
dynamo of small size. The field magnets usually revolve inside a fixed
armature (the reverse of the arrangement in a direct-current generator);
or there may be a fixed central armature and field magnets revolving
outside it. This latter arrangement is found in the great power stations
at Niagara Falls, where the enormous field-rings are mounted on the top
ends of vertical shafts, driven by water-turbines at the bottom of pits
178 feet deep, down which water is led to the turbines through great
pipes, or penstocks. The weight of each shaft and the field-ring
attached totals about thirty-five tons. This mass revolves 250 times a
minute, and 5,000 horse power is constantly developed by the dynamo.
Similar dynamos of 10,000 horse power each have been installed on the
Canadian side of the Falls.

[Illustration: FIG. 79.]


TRANSMISSION OF POWER.

Alternating current is used where power has to be transmitted for long
distances, because such a current can be intensified, or stepped up, by
a transformer somewhat similar in principle to a Ruhmkorff coil _minus_
a contact-breaker (see p. 122). A typical example of transformation is
seen in Fig. 79. Alternating current of 5,000 volts pressure is produced
in the generating station and sent through conductors to a distant
station, where a transformer, B, reduces the pressure to 500 volts to
drive an alternating motor, C, which in turn operates a direct current
dynamo, D. This dynamo has its + terminal connected with the insulated
or "live" rail of an electric railway, and its - terminal with the wheel
rails, which are metallically united at the joints to act as a
"return." On its way from the live rail to the return the current passes
through the motors. In the case of trams the conductor is either a cable
carried overhead on standards, from which it passes to the motor through
a trolley arm, or a rail laid underground in a conduit between the
rails. In the top of the conduit is a slit through which an arm carrying
a contact shoe on the end projects from the car. The shoe rubs
continuously on the live rail as the car moves.

To return for a moment to the question of transformation of current.
"Why," it may be asked, "should we not send low-pressure _direct_
current to a distant station straight from the dynamo, instead of
altering its nature and pressure? Or, at any rate, why not use
high-pressure direct current, and transform _that_?" The answer is, that
to transmit a large amount of electrical energy at low pressure (or
voltage) would necessitate large volume (or _amperage_) and a big and
expensive copper conductor to carry it. High-pressure direct current is
not easily generated, since the sparking at the collecting brushes as
they pass over the commutator segments gives trouble. So engineers
prefer high-pressure alternating current, which is easily produced, and
can be sent through a small and inexpensive conductor with little loss.
Also its voltage can be transformed by apparatus having no revolving
parts.


THE ELECTRIC MOTOR.

Anybody who understands the dynamo will also be able to understand the
electric motor, which is merely a reversed dynamo.

Imagine in Fig. 70 a dynamo taking the place of the lamp and passing
current through the brushes and commutator into the coil _w x y z_. Now,
any coil through which current passes becomes a magnet with N. and S.
poles at either end. (In Fig. 70 we will assume that the N. pole is
below and the S. pole above the coil.) The coil poles therefore try to
seek the contrary poles of the permanent magnet, and the coil revolves
until its S. pole faces the N. of the magnet, and _vice versâ_. The
lines of force of the coil and the magnet are now parallel. But the
momentum of revolution carries the coil on, and suddenly the commutator
reverses its polarity, and a further half-revolution takes place. Then
comes a further reversal, and so on _ad infinitum_. The rotation of the
motor is therefore merely a question of repulsion and attraction of like
and unlike poles. An ordinary compass needle may be converted into a
tiny motor by presenting the N. and S. poles of a magnet to its S. and
N. poles alternately every half-revolution.

In construction and winding a motor is practically the same as a dynamo.
In fact, either machine can perform either function, though perhaps not
equally well adapted for both. Motors may be run with direct or
alternating current, according to their construction.

On electric cars the motor is generally suspended from the wheel truck,
and a small pinion on the armature shaft gears with a large pinion on a
wheel axle. One great advantage of electric traction is that every
vehicle of a train can carry its own motor, so that the whole weight of
the train may be used to get a grip on the rails when starting. Where a
single steam locomotive is used, the adhesion of its driving-wheels only
is available for overcoming the inertia of the load; and the whole
strain of starting is thrown on to the foremost couplings. Other
advantages may be summed up as follows:--(1) Ease of starting and rapid
acceleration; (2) absence of waste of energy (in the shape of burning
fuel) when the vehicles are at rest; (3) absence of smoke and smell.


ELECTRIC LIGHTING.

Dynamos are used to generate current for two main purposes--(1) To
supply power to motors of all kinds; (2) to light our houses, factories,
and streets. In private houses and theatres incandescent lamps are
generally used; in the open air, in shops, and in larger buildings, such
as railway stations, the arc lamp is more often found.


INCANDESCENT LAMP.

If you take a piece of very fine iron wire and lay it across the
terminals of an accumulator, it becomes white hot and melts, owing to
the heat generated by its resistance to the current. A piece of fine
platinum wire would become white hot without melting, and would give out
an intense light. Here we have the principle of the glow or incandescent
lamp--namely, the interposition in an electric circuit of a conductor
which at once offers a high resistance to the current, but is not
destroyed by the resulting heat.

In Fig. 80 is shown a fan propelling liquid constantly through a pipe.
Let us assume that the liquid is one which develops great friction on
the inside of the pipe. At the contraction, where the speed of travel
is much greater than elsewhere in the circuit, most heat will be
produced.

[Illustration: FIG. 80.--Diagram to show circulation of water through a
pipe.]

In quite the early days of the glow-lamp platinum wire was found to be
unreliable as regards melting, and filaments of carbon are now used. To
prevent the wasting away of the carbon by combination with oxygen the
filament is enclosed in a glass bulb from which practically all air has
been sucked by a mercury pump before sealing.

[Illustration: FIG. 81.--The electrical counterpart of Fig. 80. The
filament takes the place of the contraction in the pipe.]

The manufacture of glow-lamps is now an important industry. One brand of
lamp[20] is made as follows:--First, cotton-wool is dissolved in
chloride of zinc, and forms a treacly solution, which is squirted
through a fine nozzle into a settling solution which hardens it and
makes it coil up like a very fine violin string. After being washed and
dried, it is wound on a plumbago rod and baked in a furnace until only
the carbon element remains. This is the filament in the rough. It is
next removed from the rod and tipped with two short pieces of fine
platinum wire. To make the junction electrically perfect the filament is
plunged in benzine and heated to whiteness by the passage of a strong
current, which deposits the carbon of the benzine on the joints. The
filament is now placed under the glass receiver of an air-pump, the air
is exhausted, hydro-carbon vapour is introduced, and the filament has a
current passed through it to make it white hot. Carbon from the vapour
is deposited all over the filament until the required electrical
resistance is attained. The filament is now ready for enclosure in the
bulb. When the bulb has been exhausted and sealed, the lamp is tested,
and, if passed, goes to the finishing department, where the two platinum
wires (projecting through the glass) are soldered to a couple of brass
plates, which make contact with two terminals in a lamp socket. Finally,
brass caps are affixed with a special water-tight and hard cement.


ARC LAMPS.

In _arc_ lighting, instead of a contraction at a point in the circuit,
there is an actual break of very small extent. Suppose that to the ends
of the wires leading from a dynamo's terminals we attach two carbon
rods, and touch the end of the rods together. The tips become white hot,
and if they are separated slightly, atoms of incandescent carbon leap
from the positive to the negative rod in a continuous and intensely
luminous stream, which is called an _arc_ because the path of the
particles is curved. No arc would be formed unless the carbons were
first touched to start incandescence. If they are separated too far for
the strength of the current to bridge the gap the light will flicker or
go out. The arc lamp is therefore provided with a mechanism which, when
the current is cut off, causes the carbons to fall together, gradually
separates them when it is turned on, and keeps them apart. The principle
employed is the effort of a coil through which a current passes to draw
an iron rod into its centre. Some of the current feeding the lamp is
shunted through a coil, into which projects one end of an iron bar
connected with one carbon point. A spring normally presses the points
together when no current flows. As soon as current circulates through
the coil the bar is drawn upwards against the spring.


SERIES AND PARALLEL ARRANGEMENT OF LAMPS.

When current passes from one lamp to another, as in Fig. 82, the lamps
are said to be in _series_. Should one lamp fail, all in the circuit
would go out. But where arc lamps are thus arranged a special mechanism
on each lamp "short-circuits" it in case of failure, so that current may
pass uninterruptedly to the next.

[Illustration: FIG. 82.--Incandescent lamps connected in "series."]

Fig. 83 shows a number of lamps set _in parallel_. One terminal of each
is attached to the positive conductor, the other to the negative
conductor. Each lamp therefore forms an independent bridge, and does
not affect the efficiency of the rest. _Parallel series_ signifies a
combination of the two systems, and would be illustrated if, in Fig. 83,
two or more lamps were connected in series groups from one conductor to
the other. This arrangement is often used in arc lighting.

[Illustration: FIG. 83.--Incandescent lamps connected in "parallel."]


CURRENT FOR ELECTRIC LAMPS.

This may be either direct or alternating. The former is commonly used
for arc lamps, the latter for incandescent, as it is easily stepped-down
from the high-pressure mains for use in a house. Glow-lamps usually take
current of 110 or 250 volts pressure.

In arc lamps fed with direct current the tip of the positive carbon has
a bowl-shaped depression worn in it, while the negative tip is pointed.
Most of the illumination comes from the inner surface of the bowl, and
the positive carbon is therefore placed uppermost to throw the light
downwards. An alternating current, of course, affects both carbons in
the same manner, and there is no bowl.

The carbons need frequent renewal. A powerful lamp uses about 70 feet of
rod in 1,000 hours if the arc is exposed to the air. Some lamps have
partly enclosed arcs--that is, are surrounded by globes perforated by a
single small hole, which renders combustion very slow, though preventing
a vacuum.


ELECTROPLATING.

Electroplating is the art of coating metals with metals by means of
electricity. Silver, copper, and nickel are the metals most generally
deposited. The article to be coated is suspended in a chemical solution
of the metal to be deposited. Fig. 84 shows a very simple plating
outfit. A is a battery; B a vessel containing, say, an acidulated
solution of sulphate of copper. A spoon, S, hanging in this from a glass
rod, R, is connected with the zinc or negative element, Z, of the
battery, and a plate of copper, P, with the positive element, C. Current
flows in the direction shown by the arrows, from Z to C, C to P, P to
S, S to Z. The copper deposited from the solution on the spoon is
replaced by gradual dissolution of the plate, so that the latter serves
a double purpose.

[Illustration: FIG. 84.--An electroplating outfit.]

In silver plating, P is of silver, and the solution one of cyanide of
potassium and silver salts. Where nickel or silver has to be deposited
on iron, the article is often given a preliminary coating of copper, as
iron does not make a good junction with either of the first two metals,
but has an affinity for copper.


[17] From the Latin _commuto_, "I exchange."

[18] Only the "drum" type of armature is treated here.

[19] This refers to continuous-current dynamos only.

[20] The Robertson.




Chapter X.

RAILWAY BRAKES.

     The Vacuum Automatic brake--The Westinghouse air-brake.


In the early days of the railway, the pulling up of a train necessitated
the shutting off of steam while the stopping-place was still a great
distance away. The train gradually lost its velocity, the process being
hastened to a comparatively small degree by the screw-down brakes on the
engine and guard's van. The goods train of to-day in many cases still
observes this practice, long obsolete in passenger traffic.

An advance was made when a chain, running along the entire length of the
train, was arranged so as to pull on subsidiary chains branching off
under each carriage and operating levers connected with brake blocks
pressing on every pair of wheels. The guard strained the main chain by
means of a wheel gear in his van. This system was, however, radically
defective, since, if any one branch chain was shorter than the rest, it
alone would get the strain. Furthermore, it is obvious that the snapping
of the main chain would render the whole arrangement powerless.
Accordingly, brakes operated by steam were tried. Under every carriage
was placed a cylinder, in connection with a main steam-pipe running
under the train. When the engineer wished to apply the brakes, he turned
high-pressure steam into the train pipe, and the steam, passing into the
brake cylinders, drove out in each a piston operating the brake gear.
Unfortunately, the steam, during its passage along the pipe, was
condensed, and in cold weather failed to reach the rear carriages. Water
formed in the pipes, and this was liable to freeze. If the train parted
accidentally, the apparatus of course broke down.

Hydraulic brakes have been tried; but these are open to several
objections; and railway engineers now make use of air-pressure as the
most suitable form of power. Whatever air system be adopted, experience
has shown that three features are essential:--(1.) The brakes must be
kept "off" artificially. (2.) In case of the train parting accidentally,
the brakes must be applied automatically, and quickly bring all the
vehicles of the train to a standstill. (3.) It must be possible to apply
the brakes with greater or less force, according to the needs of the
case.

At the present day one or other of two systems is used on practically
all automatically-braked cars and coaches. These are known as--(1) The
_vacuum automatic_, using the pressure of the atmosphere on a piston
from the other side of which air has been mechanically exhausted; and
(2) the _Westinghouse automatic_, using compressed air. The action of
these brakes will now be explained as simply as possible.


THE VACUUM AUTOMATIC BRAKE.

Under each carriage is a vacuum chamber (Fig. 85) riding on trunnions, E
E, so that it may swing a little when the brakes are applied. Inside the
chamber is a cylinder, the piston of which is rendered air-tight by a
rubber ring rolling between it and the cylinder walls. The piston rod
works through an air-tight stuffing-box in the bottom of the casing, and
when it rises operates the brake rods. It is obvious that if air is
exhausted from both sides of the piston at once, the piston will sink by
reason of its own weight and that of its attachments. If air is now
admitted below the piston, the latter will be pushed upwards with a
maximum pressure of 15 lbs. to the square inch. The ball-valve ensures
that while air can be sucked from _both_ sides of the piston, it can be
admitted to the lower side only.

[Illustration: FIG. 85.--Vacuum brake "off."]

[Illustration: FIG. 86.--Vacuum brake "on."]

Let us imagine that a train has been standing in a siding, and that air
has gradually filled the vacuum chamber by leakage. The engine is
coupled on, and the driver at once turns on the steam ejector,[21]
which sucks all the air out of the pipes and chambers throughout the
train. The air is sucked directly from the under side of the piston
through pipe D; and from the space A A and the cylinder (open at the
top) through the channel C, lifting the ball, which, as soon as
exhaustion is complete, or when the pressure on both sides of the piston
is equal, falls back on its seat. On air being admitted to the train
pipe, it rushes through D and into the space B (Fig. 86) below the
piston, but is unable to pass the ball, so that a strong upward pressure
is exerted on the piston, and the brakes go on. To throw them off, the
space below the piston must be exhausted. This is to be noted: If there
is a leak, as in the case of the train parting, _the brakes go on at
once_, since the vacuum below the piston is automatically broken.

[Illustration: FIG. 87.--Guard's valve for applying the Vacuum brake.]

For ordinary stops the vacuum is only partially broken--that is, an
air-pressure of but from 5 to 10 lbs. per square inch is admitted. For
emergency stops full atmospheric pressure is used. In this case it is
advisable that air should enter at _both_ ends of the train; so in the
guard's van there is installed an ingenious automatic valve, which can
at any time be opened by the guard pressing down a lever, but which
opens of itself when the train-pipe vacuum is rapidly destroyed. Fig. 87
shows this device in section. Seated on the top of an upright pipe is a
valve, _A_, connected by a bolt, B, to an elastic diaphragm, C, sealing
the bottom of the chamber D. The bolt B has a very small hole bored
through it from end to end. When the vacuum is broken slowly, the
pressure falls in D as fast as in the pipe; but a sudden inrush of air
causes the valve A to be pulled off its seat by the diaphragm C, as the
vacuum in D has not been broken to any appreciable extent. Air then
rushes into the train pipe through the valve. It is thus evident that
the driver controls this valve as effectively as if it were on the
engine. These "emergency" valves are sometimes fitted to every vehicle
of a train.

When a carriage is slipped, taps on each side of the coupling joint of
the train pipe are turned off by the guard in the "slip;" and when he
wishes to stop he merely depresses the lever E, gradually opening the
valve. Under the van is an auxiliary vacuum chamber, from which the air
is exhausted by the train pipe. If the guard, after the slip has parted
from the train, finds that he has applied his brakes too hard, he can
put this chamber into communication with the brake cylinder, and restore
the vacuum sufficiently to pull the brakes off again.

When a train has come to rest, the brakes must be sucked off by the
ejector. Until this has been done the train cannot be moved, so that it
is impossible for it to leave the station unprepared to make a sudden
stop if necessary.


THE WESTINGHOUSE AIR-BRAKE.

This system is somewhat more complicated than the vacuum, though equally
reliable and powerful. Owing to the complexity of certain parts, such as
the steam air-pump and the triple-valve, it is impossible to explain the
system in detail; we therefore have recourse to simple diagrammatic
sketches, which will help to make clear the general principles employed.

The air-brake, as first evolved by Mr. George Westinghouse, was a very
simple affair--an air-pump and reservoir on the engine; a long pipe
running along the train; and a cylinder under every vehicle to work the
brakes. To stop the train, the high-pressure air collected in the
reservoir was turned into the train pipe to force out the pistons in the
coach cylinders, connected to it by short branch pipes. One defect of
this "straight" system was that the brakes at the rear of a long train
did not come into action until a considerable time after the driver
turned on the air; and since, when danger is imminent, a very few
seconds are of great importance, this slowness of operation was a
serious fault. Also, it was found that the brakes on coaches near the
engine went on long before those more distant, so that during a quick
stop there was a danger of the forward coaches being bumped by those
behind. It goes without saying that any coaches which might break loose
were uncontrollable. Mr. Westinghouse therefore patented his _automatic_
brake, now so largely used all over the world. The brake ensures
practically instantaneous and simultaneous action on all the vehicles of
_a train of any length_.

[Illustration: FIG. 88.--Diagrammatic sketch of the details of the
Westinghouse air-brake. Brake "off."]

The principle of the brake will be gathered from Figs. 88 and 89. P is a
steam-driven air-pump on the engine, which compresses air into a
reservoir, A, situated below the engine or tender, and maintains a
pressure of from 80 to 90 lbs. per square inch. A three-way cock, C,
puts the train pipe into communication with A or the open air at the
wish of the driver. Under each coach is a triple-valve, T, an auxiliary
reservoir, B, and a brake cylinder, D. The triple-valve is the most
noteworthy feature of the whole system. The reader must remember that
the valve shown in the section is _only diagrammatic_.

Now for the operation of the brake. When the engine is coupled to the
train, the compressed air in the main reservoir is turned into the train
pipe, from which it passes through the triple-valve into the auxiliary
reservoir, and fills it till it has a pressure of, say, 80 lbs. per
square inch. Until the brakes are required, the pressure in the train
pipe must be maintained. If accidentally, or purposely (by turning the
cock C to the position shown in Fig. 89), the train-pipe pressure is
reduced, the triple-valve at once shifts, putting B in connection with
the brake cylinder D, and cutting off the connection between D and the
air, and the brakes go on. To get them off, the pressure in the train
pipe must be made equal to that in B, when the valve will assume its
original position, allowing the air in D to escape.

The force with which the brake is applied depends upon the reduction of
pressure in the train pipe. A slight reduction would admit air very
slowly from B to D, whereas a full escape from the train pipe would open
the valve to its utmost. We have not represented the means whereby the
valve is rendered sensitive to these changes, for the reason given
above.

[Illustration: FIG. 89.--Brake "on."]

The latest form of triple-valve includes a device which, when air is
rapidly discharged from the train pipe, as in an emergency application
of the brake, opens a port through which compressed air is also admitted
from the train pipe _directly_ into D. It will easily be understood that
a double advantage is hereby gained--first, in utilizing a considerable
portion of the air in the train pipe to increase the available brake
force in cases of emergency; and, secondly, in producing a quick
reduction of pressure in the whole length of the pipe, which accelerates
the action of the brakes with extraordinary rapidity.

It may be added that this secondary communication is kept open only
until the pressure in D is equal to that in the train pipe. Then it is
cut off, to prevent a return of air from B to the pipe.

An interesting detail of the system is the automatic regulation of
air-pressure in the main reservoir by the air-pump governor (Fig. 90).
The governor is attached to the steam-pipe leading from the locomotive
boiler to the air-pump. Steam from the boiler, entering at F, flows
through valve 14 and passes by D into the pump, which is thus brought
into operation, and continues to work until the pressure in the main
reservoir, acting on the under side of the diaphragm 9, exceeds the
tension to which the regulating spring 7 is set. Any excess of pressure
forces the diaphragm upwards, lifting valve 11, and allowing compressed
air from the main reservoir to flow into the chamber C. The air-pressure
forces piston 12 downwards and closes steam-valve 14, thus cutting off
the supply of steam to the pump. As soon as the pressure in the
reservoir is reduced (by leakage or use) below the normal, spring 7
returns diaphragm 9 to the position shown in Fig. 90, and pin-valve 11
closes. The compressed air previously admitted to the chamber C escapes
through the small port _a_ to the atmosphere. The steam, acting on the
lower surface of valve 14, lifts it and its piston to the position
shown, and again flows to the pump, which works until the required
air-pressure is again obtained in the reservoir.

[Illustration: FIG. 90.--Air-pump of Westinghouse brake.]


[21] This resembles the upper part of the rudimentary water injector
shown in Fig. 15. The reader need only imagine pipe B to be connected
with the train pipe. A rush of steam through pipe A creates a partial
vacuum in the cone E, causing air from the train pipe to rush into it
and be expelled by the steam blast.




Chapter XI.

RAILWAY SIGNALLING.

     The block system--Position of signals--Interlocking the
     signals--Locking gear--Points--Points and signals in
     combination--Working the block system--Series of signalling
     operations--Single line signals--The train staff--Train staff and
     ticket--Electric train staff system--Interlocking--Signalling
     operations--Power signalling--Pneumatic signalling--Automatic
     signalling.


Under certain conditions--namely, at sharp curves or in darkness--the
most powerful brakes might not avail to prevent a train running into the
rear of another, if trains were allowed to follow each other closely
over the line. It is therefore necessary to introduce an effective
system of keeping trains running in the same direction a sufficient
distance apart, and this is done by giving visible and easily understood
orders to the driver while a train is in motion.

In the early days of the railway it was customary to allow a time
interval between the passings of trains, a train not being permitted to
leave a station until at least five minutes after the start of a
preceding train. This method did not, of course, prevent collisions, as
the first train sometimes broke down soon after leaving the station; and
in the absence of effective brakes, its successor ran into it. The
advent of the electric telegraph, which put stations in rapid
communication with one another, proved of the utmost value to the safe
working of railways.


THE BLOCK SYSTEM.

Time limits were abolished and distance limits substituted. A line was
divided into _blocks_, or lengths, and two trains going in the same
direction were never allowed on any one block at the same time.

The signal-posts carrying the movable arms, or semaphores, by means of
which the signalman communicates with the engine-driver, are well known
to us. They are usually placed on the left-hand side of the line of
rails to which they apply, with their arms pointing away from the rails.
The side of the arms which faces the direction from which a train
approaches has a white stripe painted on a red background, the other
side has a black stripe on a white background.

The distant and other signal arms vary slightly in shape (Fig. 91). A
distant signal has a forked end and a V-shaped stripe; the home and
starting signals are square-ended, with straight stripes. When the arm
stands horizontally, the signal is "on," or at "danger"; when dropped,
it is "off," and indicates "All right; proceed." At the end nearest the
post it carries a spectacle frame glazed with panes of red and green
glass. When the arm is at danger, the red pane is opposite a lamp
attached to the signal post; when the arm drops, the green pane rises to
that position--so that a driver is kept as fully informed at night as
during the day, provided the lamp remains alight.

[Illustration: FIG. 91.--Distant and home signals.]


POSITION OF SIGNALS.

On double lines each set of rails has its own separate signals, and
drivers travelling on the "up" line take no notice of signals meant for
the "down" line. Each signal-box usually controls three signals on each
set of rails--the distant, the home, and the starting. Their respective
positions will be gathered from Fig. 92, which shows a station on a
double line. Between the distant and the home an interval is allowed of
800 yards on the level, 1,000 yards on a falling gradient, and 600 yards
on a rising gradient. The home stands near the approach end of the
station, and the starting at the departure end of the platform. The last
is sometimes reinforced by an "advance starting" signal some distance
farther on.

It should be noted that the distant is only a _caution_ signal, whereas
both home and starting are _stop_ signals. This means that when the
driver sees the distant "on," he does not stop his train, but slackens
speed, and prepares to stop at the home signal. He must, however, on no
account pass either home or starting if they are at danger. In short,
the distant merely warns the driver of what he may expect at the home.
To prevent damage if a driver should overrun the home, it has been laid
down that no train shall be allowed to pass the starting signal of one
box unless the line is clear to a point at least a quarter of a mile
beyond the home of the next box. That point is called the _standard
clearing point_.

Technically described, a _block_ is a length of line between the last
stop signal worked from one signal-box and the first stop signal worked
from the next signal-box in advance.

[Illustration: FIG. 92.--Showing position of signals. Those at the top
are "off."]


INTERLOCKING SIGNALS.

A signalman cannot lower or restore his signals to their normal
positions in any order he likes. He is compelled to lower them as
follows:--Starting and home; _then_ distant. And restore them--distant;
_then_ starting and home. If a signalman were quite independent, he
might, after the passage of a train, restore the home or starting, but
forget all about the distant, so that the next train, which he wants to
stop, would dash past the distant without warning and have to pull up
suddenly when the home came in sight. But by a mechanical arrangement he
is prevented from restoring the home or starting until the distant is
at danger; and, _vice versâ_, he cannot lower the last until the other
two are off. This mechanism is called _locking gear_.


LOOKING GEAR.

There are many different types of locking gear in use. It is impossible
to describe them all, or even to give particulars of an elaborate
locking-frame of any one type. But if we confine ourselves to the
simplest combination of a stud-locking apparatus, such as is used in
small boxes on the Great Western Railway, the reader will get an insight
into the general principles of these safety devices, as the same
principles underlie them all.

[Illustration: FIG. 93.--A signal lever and its connections. To move the
lever, C is pressed towards B raising the catch-rod from its nick in the
rack, G G G, guides; R R, anti-friction rollers; S, sockets for
catch-rod to work in.]

The levers in the particular type of locking gear which we are
considering have each a tailpiece or "tappet arm" attached to it, which
moves backwards and forwards with the lever (Fig. 93). Running at right
angles to this tappet, and close to it, either under or above, are the
lock bars, or stud bars. Refer now to Fig. 94, which shows the ends of
the three tappet arms, D, H, and S, crossed by a bar, B, from which
project these studs. The levers are all forward and the signals all
"on." If the signalman tried to pull the lever attached to D down the
page, as it were, he would fail to move it on account of the stud _a_,
which engages with a notch in D. Before this stud can be got free of the
notch the tappets H and S must be pulled over, so as to bring their
notches in line with studs _b_ and _c_ (Fig. 95). The signalman can now
move D, since the notch easily pushes the stud _a_ to the left (Fig.
96). The signals must be restored to danger. As H and S are back-locked
by D--that is, prevented by D from being put back into their normal
positions--D must be moved first. The interlocking of the three signals
described is merely repeated in the interlocking of a large number of
signals.

[Illustration: FIG. 94.]

[Illustration: FIG. 95.]

On entering a signal-box a visitor will notice that the levers have
different colours:--_Green_, signifying distant signals; _red_,
signifying home and starting signals; _blue_, signifying facing points;
_black_, signifying trailing points; _white_, signifying spare levers.
These different colours help the signalman to pick out the right levers
easily.

To the front of each lever is attached a small brass tablet bearing
certain numbers; one in large figures on the top, then a line, and other
numbers in small figures beneath. The large number is that of the lever
itself; the others, called _leads_, refer to levers which must be pulled
before that particular lever can be released.

[Illustration: FIG. 96.]

[Illustration: FIG. 97.--Model signal equipment in a signalling school.
(By permission of the "G.W.R. Magazine").]


POINTS.

Mention was made, in connection with the lever, of _points_. Before
going further we will glance at the action of these devices for enabling
a train to run from one set of rails to another. Figs. 98 and 99 show
the points at a simple junction. It will be noticed that the rails of
the line to the left of the points are continued as the outer rails of
the main and branch lines. The inner rails come to a sharp V-point, and
to the left of this are the two short rails which, by means of shifting
portions, decide the direction of a train's travel. In Fig. 98 the main
line is open; in Fig. 99, the branch. The shifting parts are kept
properly spaced by cross bars (or tie-rods), A A.

[Illustration: FIG. 98.--Points open to main line.]

[Illustration: FIG. 99.--Points open to branch line.]

It might be thought that the wheels would bump badly when they reach
the point B, where there is a gap. This is prevented, however, by the
bent ends E E (Fig. 98), on which the tread of the wheel rests until it
has reached some distance along the point of V. The safety rails S R
keep the outer wheel up against its rail until the V has been passed.


POINTS AND SIGNALS IN COMBINATION.

Let us suppose that a train is approaching the junction shown in Figs.
98 and 99 from the left. It is not enough that the driver should know
that the tracks are clear. He must also be assured that the track, main
or branch, as the case may be, along which he has to go, is open; and on
the other hand, if he were approaching from the right, he would want to
be certain that no train on the other line was converging on his. Danger
is avoided and assurance given by interlocking the points and signals.
To the left of the junction the home and distant signals are doubled,
there being two semaphore arms on each post. These are interlocked with
the points in such a manner that the signals referring to either line
can be pulled off only when the points are set to open the way to that
line. Moreover, before any shifting of points can be made, the signals
behind must be put to danger. The convergence of trains is prevented by
interlocking, which renders it impossible to have both sets of distant
and home signals at "All right" simultaneously.


WORKING OF BLOCK SYSTEM.

We may now pass to the working of the block system of signalling trains
from station to station on one line of a double track. Each signal-box
(except, of course, those at termini) has electric communication with
the next box in both directions. The instruments used vary on different
systems, but the principle is the same; so we will concentrate our
attention on those most commonly employed on the Great Western Railway.
They are:--(1.) Two tapper-bell instruments, connected with similar
instruments in the adjacent boxes on both sides. Each of these rings one
beat in the corresponding box every time its key is depressed. (2.) Two
Spagnoletti disc instruments--one, having two keys, communicating with
the box in the rear; and the other, in connection with the forward box,
having no keys. Their respective functions are to give signals and
receive them. In the centre of the face of each is a square opening,
behind which moves a disc carrying two "flags"--"Train on line" in white
letters on red ground, and "Line clear" in black letters on a white
ground. The keyed instrument has a red and a white key. When the red key
is depressed, "Train on line" appears at the opening; also in that of a
keyless disc at the adjacent signal-box. A depression of the white key
similarly gives "Line clear." A piece of wire with the ends turned over
and passed through two eyes slides over the keys, and can be made to
hold either down. In addition to these, telephonic and telegraphic
instruments are provided to enable the signalmen to converse.


SERIES OF SIGNALLING OPERATIONS.

[Illustration: FIG. 100.--The signaling instruments in three adjacent
cabins. The featherless arrows show the connection of the instruments.]

We may now watch the doings of signalmen in four successive boxes, A,
B, C, and D, during the passage of an express train. Signalman A calls
signalman B's attention by one beat on the tapper-bell. B answers by
repeating it to show that he is attending. A asks, "Is line clear for
passenger express?"--four beats on the bell. B, seeing that the line is
clear to his clearing point, sends back four beats, and pins down the
white key of his instrument. "Line clear" appears on the opening, and
also at that of A's keyless disc. A lowers starting signal. Train moves
off. A gives two beats on the tapper = "Train entering section." B pins
indicator at "Train on line," which also appears on A's instrument. A
places signals at danger. B asks C, "Is line clear?" C repeats the bell
code, and pins indicator at "Line clear," shown on B's keyless disc
also. B lowers all signals. Train passes. B signals to C, "Train
entering section." B signals to A, "Train out of section," and releases
indicator, which returns to normal position with half of each flag
showing at the window. B signals to C, "Train on line," and sets all his
signals to danger. C pins indicator to "Train on line." C asks, "Is line
clear?" But there is a train at station D, and signalman D therefore
gives no reply, which is equivalent to a negative. The driver, on
approaching C's distant, sees it at danger, and slows down, stopping at
the home. C lowers home, and allows train to proceed to his starting
signal. D, when the line is clear to his clearing point, signals "Line
clear," and pins indicator at "Line clear." C lowers starting signals,
and train proceeds. C signals to D, "Train entering section," and D pins
indicator at "Train on line." C signals to B, "Train out of section,"
sets indicator at normal, and puts signals at danger. And so the process
is repeated from station to station. Where, however, sections are short,
the signalman is advised one section ahead of the approach of a train by
an additional signal signifying, "Fast train approaching." The block
indicator reminds the signalman of the whereabouts of the train. Unless
his keyless indicator is at normal, he may not ask, "Is line clear?" And
until he signals back "Line clear" to the box behind, a train is not
allowed to enter his section. In this way a section of line with a full
complement of signals is always interposed between any two trains.


THE WORKING OF SINGLE LINES.

We have dealt with the signalling arrangements pertaining to double
lines of railway, showing that a system of signals is necessary to
prevent a train running into the back of its predecessor. Where trains
in both directions pass over a single line, not only has this element of
danger to be dealt with, but also the possibility of a train being
allowed to enter a section of line from each end _at the same time_.
This is effected in several ways, the essence of each being that the
engine-driver shall have in his possession _visible_ evidence of the
permission accorded him by the signalman to enter a section of single
line.


A SINGLE TRAIN STAFF.

The simplest form of working is to allocate to the length of line a
"train staff"--a piece of wood about 14 inches long, bearing the names
of the stations at either end. This is adopted where only one engine is
used for working a section, such as a short branch line. In a case like
this there is obviously no danger of two trains meeting, and the train
staff is merely the authority to the driver to start a journey. No
telegraphic communication is necessary with such a system, and signals
are placed only at the ends of the line.


TRAIN STAFF AND TICKET.

On long lengths of single line where more than one train has to be
considered, the line is divided into blocks in the way already described
for double lines, and a staff is assigned to each, the staffs for the
various blocks differing from each other in shape and colour. The usual
signals are provided at each station, and block telegraph instruments
are employed, the only difference being that one disc, of the key
pattern, is used for trains in both directions. On such a line it is, of
course, possible that two or more trains may require to follow each
other without any travelling intermediately in the opposite direction.
This would be impossible if the staff passed uniformly to and fro in the
block section; but it is arranged by the introduction of a train staff
_ticket_ used in conjunction with the staff.

No train is permitted to leave a staff station unless the staff for the
section of line to be traversed is at the station; and the driver has
the strictest possible instructions that he must _see_ the staff. If a
second train is required to follow, the staff is _shown_ to the driver,
and a train staff ticket handed him as his authority to proceed. If,
however, the next train over the section will enter from the opposite
end, the staff is _handed_ to the driver.

To render this system as safe as possible, train staff tickets are of
the same colour and shape as the staff for the section to which they
apply, and are kept in a special box at the stations, the key being
attached to the staff and the lock so arranged that the key cannot be
withdrawn unless the box has been locked.


ELECTRIC TRAIN STAFF AND TABLET SYSTEMS.

These systems of working are developments of the last mentioned, by
which are secured greater safety and ease in working the line. On some
sections of single line circumstances often necessitate the running of
several trains in one direction without a return train. For such cases
the train staff ticket was introduced; but even on the best regulated
lines it is not always possible to secure that the staff shall be at the
station where it is required at the right time, and cases have arisen
where, no train being available at the station where the staff was, it
had to be taken to the other station by a man on foot, causing much
delay to traffic. The electric train staff and tablet systems overcome
this difficulty. Both work on much the same principle, and we will
therefore describe the former.

[Illustration: FIG. 101.--An electric train staff holder: S S, staffs
in the slot of the instrument. Leaning against the side of the cabin is
a staff showing the key K at the end for unlocking a siding points
between two stations. The engine driver cannot remove the staff until
the points have been locked again.]

At each end of a block section a train staff instrument (Fig. 101) is
provided. In the base of these instruments are a number of train staffs,
any one of which would be accepted by an engine-driver as permission to
travel over the single line. The instruments are electrically connected,
the mechanism securing that a staff can be withdrawn only by the
co-operation of the signalman at each end of the section; that, when
_all_ the staffs are in the instruments, a staff may be withdrawn at
_either_ end; that, when a staff has been withdrawn, another cannot be
obtained until the one out has been restored to one or other of the
instruments. The safety of such a system is obvious, as also the
assistance to the working by having a staff available for a train no
matter from which end it is to enter the section.

The mechanism of the instruments is quite simple. A double-poled
electro-magnet is energized by the depression of a key by the signalman
at the further end of the block into which the train is to run, and by
the turning of a handle by the signalman who requires to withdraw a
staff. The magnet, being energized, is able to lift a mechanical lock,
and permits the withdrawal of a staff. In its passage through the
instrument the staff revolves a number of iron discs, which in turn
raise or lower a switch controlling the electrical connections. This
causes the electric currents actuating the electro-magnet to oppose
each other, the magnetism to cease, and the lock to fall back,
preventing another staff being withdrawn. It will naturally be asked,
"How is the electrical system restored?" We have said that there were a
number of staffs in each instrument--in other words, a given number of
staffs, usually twenty, is assigned to the section. Assume that there
are ten in each instrument, and that the switch in each is in its lower
position. Now withdraw a staff, and one instrument has an odd, the other
an even, number of staffs, and similarly one switch is raised while the
other remains lowered, therefore the electrical circuit is "out of
phase"--that is, the currents in the magnets of each staff instrument
are opposed to one another, and cannot release the lock. The staff
travels through the section and is placed in the instrument at the other
end, bringing the number of staffs to eleven--an odd number, and, what
is more important, _raising_ the switch. Both switches are now raised,
consequently the electric currents will support each other, so that a
staff may be withdrawn. Briefly, then, when there is an odd number of
staffs in one instrument and an even number in the other, as when a
staff is in use, the signalmen are unable to obtain a staff, and
consequently cannot give authority for a train to enter the section; but
when there is either an odd or an even number of staffs in each
instrument a staff may be withdrawn at either end on the co-operation of
the signalmen.

We may add that, where two instruments are in the same signal-box, one
for working to the box in advance, the other to the rear, it is arranged
that the staffs pertaining to one section shall not fit the instrument
for the other, and must be of different colours. This prevents the
driver accidentally accepting a staff belonging to one section as
authority to travel over the other.


INTERLOCKING.

The remarks made on the interlocking of points and signals on double
lines apply also to the working of single lines, with the addition that
not only are the distant, home, and starting signals interlocked with
each other, but with the signals and points governing the approach of a
train from the opposite direction--in other words, the signals for the
approach of a train to a station from one direction cannot be lowered
unless those for the approach to the station of a train from the
opposite direction are at danger, and the points correctly set.


SIGNALLING OPERATIONS.

In the working of single lines, as of double, the signalman at the
station from which a train is to proceed has to obtain the consent of
the signalman ahead, the series of questions to be signalled being very
similar to those detailed for double lines. There is, however, one
notable exception. On long lengths of single line it is necessary to
make arrangements for trains to pass each other. This is done by
providing loop lines at intervals, a second pair of rails being laid for
the accommodation of one train while another in the opposite direction
passes it. To secure that more than one train shall not be on a section
of single line between two crossing-places it is laid down that, when a
signalman at a non-crossing station is asked to allow a train to
approach his station, he must not give permission until he has notified
the signalman ahead of him, thus securing that he is not asking
permission for trains to approach from both directions at the same time.
Both for single and double line working a number of rules designed to
deal with cases of emergency are laid down, the guiding principle being
safety; but we have now dealt with all the conditions of everyday
working, and must pass to the consideration of

[Illustration: FIG. 102.--An electric lever-frame in a signalling cabin
at Didcot.]


"POWER" SIGNALLING.

In a power system of signalling the signalman is provided with some
auxiliary means--electricity, compressed air, etc.--of moving the
signals or points under his control. It is still necessary to have a
locking-frame in the signal-box, with levers interlocked with each
other, and connections between the box and the various points and
signals. But the frame is much smaller than an ordinary manual frame,
and but little force is needed to move the little levers which make or
break an electric circuit, or open an air-valve, according to the
power-agent used.


ELECTRIC SIGNALLING.

Fig. 102 represents the locking-frame of a cabin at Didcot, England,
where an all-electric system has been installed. Wires lead from the
cabin to motors situated at the points and signals, which they operate
through worm gearing. When a lever is moved it closes a circuit and sets
the current flowing through a motor, the direction of the flow (and
consequently of the motor's revolution) depending on whether the lever
has been moved forward or backward. Indicators arranged under the levers
tell the signalman when the desired movements at the points and signals
have been completed. If any motion is not carried through, owing to
failure of the current or obstruction of the working parts, an electric
lock prevents him continuing operations. Thus, suppose he has to open
the main line to an express, he is obliged by the mechanical
locking-frame to set all the points correctly before the signals can be
lowered. He might move all the necessary levers in due order, yet one
set of points might remain open, and, were the signals lowered, an
accident would result. But this cannot happen, as the electric locks
worked by the points in question block the signal levers, and until the
failure has been set right, the signals must remain at "danger."

The point motors are connected direct to the points; but between a
signal motor and its arm there is an "electric slot," consisting of a
powerful electro-magnet which forms a link in the rod work. To lower a
signal it is necessary that the motor shall revolve and a control
current pass round the magnet to give it the requisite attractive force.
If no control current flows, as would happen were any pair of points not
in their proper position, the motor can have no effect on the signal arm
to lower it, owing to the magnet letting go its grip. Furthermore, if
the signal had been already lowered when the control current failed, it
would rise to "danger" automatically, as all signals are weighted to
assume the danger position by gravity. The signal control currents can
be broken by the signalman moving a switch, so that in case of emergency
all signals may be thrown simultaneously to danger.


PNEUMATIC SIGNALLING.

In England and the United States compressed air is also used to do the
hard labour of the signalman for him. Instead of closing a circuit, the
signalman, by moving a lever half-way over, admits air to a pipe running
along the track to an air reservoir placed beside the points or signal
to which the lever relates. The air opens a valve and puts the reservoir
in connection with a piston operating the points or signal-arm, as the
case may be. This movement having been performed, another valve in the
reservoir is opened, and air passes back through a second pipe to the
signal-box, where it opens a third valve controlling a piston which
completes the movement of the lever, so showing the signalman that the
operation is complete. With compressed air, as with electricity, a
mechanical locking-frame is of course used.


AUTOMATIC SIGNALLING.

To reduce expense, and increase the running speed on lines where the
sections are short, the train is sometimes made to act as its own
signalman. The rails of each section are all bonded together so as to be
in metallic contact, and each section is insulated from the two
neighbouring sections. At the further end of a section is installed an
electric battery, connected to the rails, which lead the current back to
a magnet operating a signal stationed some distance back on the
preceding section. As long as current flows the signal is held at "All
right." When a train enters the section the wheels and axles
short-circuit the current, so that it does not reach the signal magnet,
and the signal rises to "danger," and stays there until the last pair of
wheels has passed out of the section. Should the current fail or a
vehicle break loose and remain on the section, the same thing would
happen.

The human element can thus be practically eliminated from signalling. To
make things absolutely safe, a train should have positive control over a
train following, to prevent the driver overrunning the signals. On
electric railways this has been effected by means of contacts working
in combination with the signals, which either cut the current off from
the section preceding that on which a train may be, or raise a trigger
to strike an arm on the train following and apply its brakes.




Chapter XII.

OPTICS.

     Lenses--The image cast by a convex lens--Focus--Relative position
     of object and lens--Correction of lenses for colour--Spherical
     aberration--Distortion of image--The human eye--The use of
     spectacles--The blind spot.


Light is a third form of that energy of which we have already treated
two manifestations--heat and electricity. The distinguishing
characteristic of ether light-waves is their extreme rapidity of
vibration, which has been calculated to range from 700 billion movements
per second for violet rays to 400 billion for red rays.

If a beam of white light be passed through a prism it is resolved into
the seven visible colours of the spectrum--violet, indigo, blue, green,
yellow, orange, and red--in this order. The human eye is most sensitive
to the yellow-red rays, a photographic plate to the green-violet rays.

All bodies fall into one of two classes--(1) _Luminous_--that is, those
which are a _source_ of light, such as the sun, a candle flame, or a
red-hot coal; and (2) _non-luminous_, which become visible only by
virtue of light which they receive from other bodies and reflect to our
eyes.


THE PROPAGATION OF LIGHT.

Light naturally travels in a straight line. It is deflected only when it
passes from one transparent medium into another--for example, from air
to water--and the mediums are of different densities. We may regard the
surface of a visible object as made up of countless points, from each of
which a diverging pencil of rays is sent off through the ether.


LENSES.

If a beam of light encounters a transparent glass body with non-parallel
sides, the rays are deflected. The direction they take depends on the
shape of the body, but it may be laid down as a rule that they are bent
toward the thicker part of the glass. The common burning-glass is well
known to us. We hold it up facing the sun to concentrate all the heat
rays that fall upon it into one intensely brilliant spot, which speedily
ignites any inflammable substance on which it may fall (Fig. 103). We
may imagine that one ray passes from the centre of the sun through the
centre of the glass. This is undeflected; but all the others are bent
towards it, as they pass through the thinner parts of the lens.

[Illustration: FIG. 103.--Showing how a burning-glass concentrates the
heat rays which fall upon it.]

It should be noted here that _sunlight_, as we call it, is accompanied
by heat. A burning-glass is used to concentrate the _heat_ rays, not the
_light_ rays, which, though they are collected too, have no igniting
effect.

In photography we use a lens to concentrate light rays only. Such heat
rays as may pass through the lens with them are not wanted, and as they
have no practical effect are not taken any notice of. To be of real
value, a lens must be quite symmetrical--that is, the curve from the
centre to the circumference must be the same in all directions.

There are six forms of simple lenses, as given in Fig. 104. Nos. 1 and
2 have one flat and one spherical surface. Nos. 3, 4, 5, 6 have two
spherical surfaces. When a lens is thicker at the middle than at the
sides it is called a _convex_ lens; when thinner, a _concave_ lens. The
names of the various shapes are as follows:--No. 1, plano-convex; No. 2,
plano-concave; No. 3, double convex; No. 4, double concave; No. 5,
meniscus; No. 6, concavo-convex. The thick-centre lenses, as we may term
them (Nos. 1, 3, 5), _concentrate_ a pencil of rays passing through
them; while the thin-centre lenses (Nos. 2, 4, 6) _scatter_ the rays
(see Fig. 105).

[Illustration: FIG. 104.--Six forms of lenses.]


THE CAMERA.

[Illustration: FIG. 105.]

[Illustration: FIG. 106.]

We said above that light is propagated in straight lines. To prove this
is easy. Get a piece of cardboard and prick a hole in it. Set this up
some distance away from a candle flame, and hold behind it a piece of
tissue paper. You will at once perceive a faint, upside-down image of
the flame on the tissue. Why is this? Turn for a moment to Fig. 106,
which shows a "pinhole" camera in section. At the rear is a ground-glass
screen, B, to catch the image. Suppose that A is the lowest point of the
flame. A pencil of rays diverging from it strikes the front of the
camera, which stops them all except the one which passes through the
hole and makes a tiny luminous spot on B, _above_ the centre of the
screen, though A is below the axis of the camera. Similarly the tip of
the flame (above the axis) would be represented by a dot on the screen
below its centre. And so on for all the millions of points of the flame.
If we were to enlarge the hole we should get a brighter image, but it
would have less sharp outlines, because a number of rays from every
point of the candle would reach the screen and be jumbled up with the
rays of neighbouring pencils. Now, though a good, sharp photograph may
be taken through a pinhole, the time required is so long that
photography of this sort has little practical value. What we want is a
large hole for the light to enter the camera by, and yet to secure a
distinct image. If we place a lens in the hole we can fulfil our wish.
Fig. 107 shows a lens in position, gathering up a number of rays from a
point, A, and focussing them on a point, B. If the lens has 1,000 times
the area of the pinhole, it will pass 1,000 times as many rays, and the
image of A will be impressed on a sensitized photographic plate 1,000
times more quickly.

[Illustration: FIG. 107.]


THE IMAGE CAST BY A CONVEX LENS.

Fig. 108 shows diagrammatically how a convex lens forms an image. From A
and B, the extremities of the object, a simple ray is considered to pass
through the centre of the lens. This is not deflected at all. Two other
rays from the same points strike the lens above and below the centre
respectively. These are bent inwards and meet the central rays, or come
to a focus with them at A^1 and B^1. In reality a countless number
of rays would be transmitted from every point of the object and
collected to form the image.

[Illustration: FIG. 108.--Showing how an image is cast by a convex
lens.]


FOCUS.

We must now take special notice of that word heard so often in
photographic talk--"focus." What is meant by the focus or focal length
of a lens? Well, it merely signifies the distance between the optical
centre of the lens and the plane in which the image is formed.

[Illustration: FIG. 109.]

We must here digress a moment to draw attention to the three simple
diagrams of Fig. 109. The object, O, in each case is assumed to be to
the right of the lens. In the topmost diagram the object is so far away
from the lens that all rays coming from a single point in it are
practically parallel. These converge to a focus at F. If the distance
between F and the centre of the lens is six inches, we say that the
lens has a six-inch focal length. The focal length of a lens is judged
by the distance between lens and image when the object is far away. To
avoid confusion, this focal length is known as the _principal_ focus,
and is denoted by the symbol f. In the middle diagram the object is
quite near the lens, which has to deal with rays striking its nearer
surface at an acuter angle than before (reckoning from the centre). As
the lens can only deflect their path to a fixed degree, they will not,
after passing the lens, come together until they have reached a point,
F^1, further from the lens than F. The nearer we approach O to the
lens, the further away on the other side is the focal point, until a
distance equal to that of F from the lens is reached, when the rays
emerge from the glass in a parallel pencil. The rays now come to a focus
no longer, and there can be no image. If O be brought nearer than the
focal distance, the rays would _diverge_ after passing through the lens.


RELATIVE POSITIONS OF OBJECT AND IMAGE.

[Illustration: FIG. 110.--Showing how the position of the image alters
relatively to the position of the object.]

From what has been said above we deduce two main conclusions--(1.) The
nearer an object is brought to the lens, the further away from the lens
will the image be. (2.) If the object approaches within the principal
focal distance of the lens, no image will be cast by the lens. To make
this plainer we append a diagram (Fig. 110), which shows five positions
of an object and the relative positions of the image (in dotted lines).
First, we note that the line A B, or A B^1, denotes the principal
focal length of the lens, and A C, or A C^1, denotes twice the focal
length. We will take the positions in order:--

_Position I._ Object further away than 2_f_. Inverted image _smaller_
than object, at distance somewhat exceeding _f_.

_Position II._ Object at distance = 2_f_. Inverted image at distance =
2_f_, and of size equal to that of object.

_Position III_ Object nearer than 2_f_. Inverted image further away than
2_f_; _larger_ than the object.

_Position IV._ Object at distance = _f_. As rays are parallel after
passing the lens _no_ image is cast.

_Position V._ Object at distance less than _f_. No real image--that is,
one that can be caught on a focussing screen--is now given by the lens,
but a magnified, erect, _virtual_ image exists on the same side of the
lens as the object.

We shall refer to _virtual_ images at greater length presently. It is
hoped that any reader who practises photography will now understand why
it is necessary to rack his camera out beyond the ordinary focal
distance when taking objects at close quarters. From Fig. 110 he may
gather one practically useful hint--namely, that to copy a diagram,
etc., full size, both it and the plate must be exactly 2_f_ from the
optical centre of the lens. And it follows from this that the further he
can rack his camera out beyond 2_f_ the greater will be the possible
enlargement of the original.


CORRECTION OF LENSES FOR COLOUR.

We have referred to the separation of the spectrum colours of white
light by a prism. Now, a lens is one form of prism, and therefore sorts
out the colours. In Fig. 111 we assume that two parallel red rays and
two parallel violet rays from a distant object pass through a lens. A
lens has most bending effect on violet rays and least on red, and the
other colours of the spectrum are intermediately influenced. For the
sake of simplicity we have taken the two extremes only. You observe that
the point R, in which the red rays meet, is much further from the lens
than is V, the meeting-point of the violet rays. A photographer very
seldom has to take a subject in which there are not objects of several
different colours, and it is obvious that if he used a simple lens like
that in Fig. 111 and got his red objects in good focus, the blue and
green portions of his picture would necessarily be more or less out of
focus.

[Illustration: FIG. 111.]

[Illustration: FIG. 112.]

This defect can fortunately be corrected by the method shown in Fig.
112. A _compound_ lens is needed, made up of a _crown_ glass convex
element, B, and a concave element, A, of _flint_ glass. For the sake of
illustration the two parts are shown separated; in practice they would
be cemented together, forming one optical body, thicker in the centre
than at the edges--a meniscus lens in fact, since A is not so concave as
B is convex. Now, it was discovered by a Mr. Hall many years ago that if
white light passed through two similar prisms, one of flint glass the
other of crown glass, the former had the greater effect in separating
the spectrum colours--that is, violet rays were bent aside more suddenly
compared with the red rays than happened with the crown-glass prism.
Look at Fig. 112. The red rays passing through the flint glass are but
little deflected, while the violet rays turn suddenly outwards. This is
just what is wanted, for it counteracts the unequal inward refraction
by B, and both sets of rays come to a focus in the same plane. Such a
lens is called _achromatic_, or colourless. If you hold a common
reading-glass some distance away from large print you will see that the
letters are edged with coloured bands, proving that the lens is not
achromatic. A properly corrected photographic lens would not show these
pretty edgings. Colour correction is necessary also for lenses used in
telescopes and microscopes.


SPHERICAL ABERRATION.

A lens which has been corrected for colour is still imperfect. If rays
pass through all parts of it, those which strike it near the edge will
be refracted more than those near the centre, and a blurred focus
results. This is termed _spherical aberration_. You will be able to
understand the reason from Figs. 113 and 114. Two rays, A, are parallel
to the axis and enter the lens near the centre (Fig. 113). These meet in
one plane. Two other rays, B, strike the lens very obliquely near the
edge, and on that account are both turned sharply upwards, coming to a
focus in a plane nearer the lens than A. If this happened in a camera
the results would be very bad. Either A or B would be out of focus. The
trouble is minimized by placing in front of the lens a plate with a
central circular opening in it (denoted by the thick, dark line in Fig.
114). The rays B of Fig. 113 are stopped by this plate, which is
therefore called a _stop_. But other rays from the same point pass
through the hole. These, however, strike the lens much more squarely
above the centre, and are not unduly refracted, so that they are brought
to a focus in the same plane as rays A.

[Illustration: FIG. 113.]

[Illustration: FIG. 114.]


DISTORTION OF IMAGE.

[Illustration: FIG. 115.--Section of a rectilinear lens.]

The lens we have been considering is a single meniscus, such as is used
in landscape photography, mounted with the convex side turned towards
the inside of the camera, and having the stop in front of it. If you
possess a lens of this sort, try the following experiment with it. Draw
a large square on a sheet of white paper and focus it on the screen. The
sides instead of being straight bow outwards: this is called _barrel_
distortion. Now turn the lens mount round so that the lens is outwards
and the stop inwards. The sides of the square will appear to bow towards
the centre: this is _pin-cushion_ distortion. For a long time opticians
were unable to find a remedy. Then Mr. George S. Cundell suggested that
_two_ meniscus lenses should be used in combination, one on either side
of the stop, as in Fig 115. Each produces distortion, but it is
counteracted by the opposite distortion of the other, and a square is
represented as a square. Lenses of this kind are called _rectilinear_,
or straight-line producing.

We have now reviewed the three chief defects of a lens--chromatic
aberration, spherical aberration, and distortion--and have seen how they
may be remedied. So we will now pass on to the most perfect of cameras,


THE HUMAN EYE.

The eye (Fig. 116) is nearly spherical in form, and is surrounded
outside, except in front, by a hard, horny coat called the _sclerotica_
(S). In front is the _cornea_ (A), which bulges outwards, and acts as a
transparent window to admit light to the lens of the eye (C). Inside the
sclerotica, and next to it, comes the _choroid_ coat; and inside that
again is the _retina_, or curved focussing screen of the eye, which may
best be described as a network of fibres ramifying from the optic nerve,
which carries sight sensations to the brain. The hollow of the ball is
full of a jelly-like substance called the _vitreous humour_; and the
cavity between the lens and the cornea is full of water.

We have already seen that, in focussing, the distance between lens and
image depends on the distance between object and lens. Now, the retina
cannot be pushed nearer to or pulled further away from its lens, like
the focussing screen of a camera. How, then, is the eye able to focus
sharply objects at distances varying from a foot to many miles?

[Illustration: FIG. 116.--Section of the human eye.]

As a preliminary to the answer we must observe that the more convex a
lens is, the shorter is its focus. We will suppose that we have a box
camera with a lens of six-inch focus fixed rigidly in the position
necessary for obtaining a sharp image of distant objects. It so happens
that we want to take with it a portrait of a person only a few feet from
the lens. If it were a bellows camera, we should rack out the back or
front. But we cannot do this here. So we place in front of our lens a
second convex lens which shortens its principal focus; so that _in
effect_ the box has been racked out sufficiently.

Nature, however, employs a much more perfect method than this. The eye
lens is plastic, like a piece of india-rubber. Its edges are attached to
ligaments (L L), which pull outwards and tend to flatten the curve of
its surfaces. The normal focus is for distant objects. When we read a
book the eye adapts itself to the work. The ligaments relax and the lens
decreases in diameter while thickening at the centre, until its
curvature is such as to focus all rays from the book sharply on the
retina. If we suddenly look through the window at something outside, the
ligaments pull on the lens envelope and flatten the curves.

This wonderful lens is achromatic, and free from spherical aberration
and distortion of image. Nor must we forget that it is aided by an
automatic "stop," the _iris_, the central hole of which is named the
_pupil_. We say that a person has black, blue, or gray eyes according to
the colour of the iris. Like the lens, the iris adapts itself to all
conditions, contracting when the light is strong, and opening when the
light is weak, so that as uniform an amount of light as conditions allow
may be admitted to the eye. Most modern camera lenses are fitted with
adjustable stops which can be made larger or smaller by twisting a ring
on the mount, and are named "iris" stops. The image of anything seen is
thrown on the retina upside down, and the brain reverses the position
again, so that we get a correct impression of things.


THE USE OF SPECTACLES.

[Illustration: FIG. 117_a_.]

[Illustration: FIG. 117_b_.]

[Illustration: FIG. 118_a_.]

[Illustration: FIG. 118_b_.]

The reader will now be able to understand without much trouble the
function of a pair of spectacles. A great many people of all ages suffer
from short-sight. For one reason or another the distance between lens
and retina becomes too great for a person to distinguish distant objects
clearly. The lens, as shown in Fig 117_a_, is too convex--has its
minimum focus too short--and the rays meet and cross before they reach
the retina, causing general confusion of outline. This defect is simply
remedied by placing in front of the eye (Fig. 117_b_) a _concave_ lens,
to disperse the rays somewhat before they enter the eye, so that they
come to a focus on the retina. If a person's sight is thus corrected for
distant objects, he can still see near objects quite plainly, as the
lens will accommodate its convexity for them. The scientific term for
short-sight is _myopia_. Long-sight, or _hypermetropia_, signifies that
the eyeball is too short or the lens too flat. Fig. 118_a_ represents
the normal condition of a long-sighted eye. When looking at a distant
object the eye thickens slightly and brings the focus forward into the
retina. But its thickening power in such an eye is very limited, and
consequently the rays from a near object focus behind the retina. It is
therefore necessary for a long-sighted person to use _convex_ spectacles
for reading the newspaper. As seen in Fig. 118_b_, the spectacle lens
concentrates the rays before they enter the eye, and so does part of the
eye's work for it.

Returning for a moment to the diagram of the eye (Fig. 116), we notice a
black patch on the retina near the optic nerve. This is the "yellow
spot." Vision is most distinct when the image of the object looked at is
formed on this part of the retina. The "blind spot" is that point at
which the optic nerve enters the retina, being so called from the fact
that it is quite insensitive to light. The finding of the blind spot is
an interesting little experiment. On a card make a large and a small
spot three inches apart, the one an eighth, the other half an inch in
diameter. Bring the card near the face so that an eye is exactly
opposite to each spot, and close the eye opposite to the smaller. Now
direct the other eye to this spot and you will find, if the card be
moved backwards and forwards, that at a certain distance the large spot,
though many times larger than its fellow, has completely vanished,
because the rays from it enter the open eye obliquely and fall on the
"blind spot."




Chapter XIII.

THE MICROSCOPE, THE TELESCOPE, AND THE MAGIC-LANTERN.

     The simple microscope--Use of the simple microscope in the
     telescope--The terrestrial telescope--The Galilean telescope--The
     prismatic telescope--The reflecting telescope--The parabolic
     mirror--The compound microscope--The magic-lantern--The
     bioscope--The plane mirror.


In Fig. 119 is represented an eye looking at a vase, three inches high,
situated at A, a foot away. If we were to place another vase, B, six
inches high, at a distance of two feet; or C, nine inches high, at three
feet; or D, a foot high, at four feet, the image on the retina would in
every case be of the same size as that cast by A. We can therefore lay
down the rule that _the apparent size of an object depends on the angle
that it subtends at the eye_.

[Illustration: FIG. 119.]

To see a thing more plainly, we go nearer to it; and if it be very
small, we hold it close to the eye. There is, however, a limit to the
nearness to which it can be brought with advantage. The normal eye is
unable to adapt its focus to an object less than about ten inches away,
termed the "least distance of distinct vision."


THE SIMPLE MICROSCOPE.

[Illustration: FIG. 120.]

A magnifying glass comes in useful when we want to examine an object
very closely. The glass is a lens of short focus, held at a distance
somewhat less than its principal focal length, F (see Fig. 120), from
the object. The rays from the head and tip of the pin which enter the
eye are denoted by continuous lines. As they are deflected by the glass
the eye gets the _impression_ that a much longer pin is situated a
considerable distance behind the real object in the plane in which the
refracted rays would meet if produced backwards (shown by the dotted
lines). The effect of the glass, practically, is to remove it (the
object) to beyond the least distance of distinct vision, and at the same
time to retain undiminished the angle it subtends at the eye, or, what
amounts to the same thing, the actual size of the image formed on the
retina.[22] It follows, therefore, that if a lens be of such short focus
that it allows us to see an object clearly at a distance of two
inches--that is, one-fifth of the least distance of distinct vision--we
shall get an image on the retina five times larger in diameter than
would be possible without the lens.

The two simple diagrams (Figs. 121 and 122) show why the image to be
magnified should be nearer to the lens than the principal focus, F. We
have already seen (Fig. 109) that rays coming from a point in the
principal focal plane emerge as a parallel pencil. These the eye can
bring to a focus, because it normally has a curvature for focussing
parallel rays. But, owing to the power of "accommodation," it can also
focus _diverging_ rays (Fig. 121), the eye lens thickening the necessary
amount, and we therefore put our magnifying glass a bit nearer than F to
get full advantage of proximity. If we had the object _outside_ the
principal focus, as in Fig. 122, the rays from it would converge, and
these could not be gathered to a sharp point by the eye lens, as it
cannot _flatten_ more than is required for focussing parallel rays.

[Illustration: FIG. 121.]

[Illustration: FIG. 122.]


USE OF THE SIMPLE MICROSCOPE IN THE TELESCOPE.

[Illustration: FIG. 123.]

Let us now turn to Fig. 123. At A is a distant object, say, a hundred
yards away. B is a double convex lens, which has a focal length of
twenty inches. We may suppose that it is a lens in a camera. An inverted
image of the object is cast by the lens at C. If the eye were placed at
C, it would distinguish nothing. But if withdrawn to D, the least
distance of distinct vision,[23] behind C, the image is seen clearly.
That the image really is at C is proved by letting down the focussing
screen, which at once catches it. Now, as the focus of the lens is twice
_d_, the image will be twice as large as the object would appear if
viewed directly without the lens. We may put this into a very simple
formula:--

  Magnification = focal length of lens
                  --------------------
                      _d_

[Illustration: FIG. 124.]

In Fig. 124 we have interposed between the eye and the object a small
magnifying glass of 2-1/2-inch focus, so that the eye can now clearly
see the image when one-quarter _d_ away from it. B already magnifies the
image twice; the eye-piece again magnifies it four times; so that the
total magnification is 2 × 4 = 8 times. This result is arrived at
quickly by dividing the focus of B (which corresponds to the
object-glass of a telescope) by the focus of the eye-piece, thus:--

    20
   ____ = 8
  2-1/2

The ordinary astronomical telescope has a very long focus object-glass
at one end of the tube, and a very short focus eye-piece at the other.
To see an object clearly one merely has to push in or pull out the
eye-piece until its focus exactly corresponds with that of the
object-glass.


THE TERRESTRIAL TELESCOPE.

An astronomical telescope inverts images. This inversion is inconvenient
for other purposes. So the terrestrial telescope (such as is commonly
used by sailors) has an eye-piece compounded of four convex lenses which
erect as well as magnify the image. Fig. 125 shows the simplest form of
compound erecting eye-piece.

[Illustration: FIG. 125.]


THE GALILEAN TELESCOPE.

[Illustration: FIG. 126.]

A third form of telescope is that invented by the great Italian
astronomer, Galileo,[24] in 1609. Its principle is shown in Fig. 126.
The rays transmitted by the object-glass are caught, _before_ coming to
a focus, on a concave lens which separates them so that they appear to
meet in the paths of convergence denoted by the dotted lines. The image
is erect. Opera-glasses are constructed on the Galilean principle.


THE PRISMATIC TELESCOPE.

In order to be able to use a long-focus object-glass without a long
focussing-tube, a system of glass reflecting prisms is sometimes
employed, as in Fig. 127. A ray passing through the object-glass is
reflected from one posterior surface of prism A on to the other
posterior surface, and by it out through the front on to a second prism
arranged at right angles to it, which passes the ray on to the compound
eye-piece. The distance between object-glass and eye-piece is thus
practically trebled. The best-known prismatic telescopes are the Zeiss
field-glasses.

[Illustration: FIG. 127.]


THE REFLECTING TELESCOPE.

We must not omit reference to the _reflecting_ telescope, so largely
used by astronomers. The front end of the telescope is open, there being
no object-glass. Rays from the object fall on a parabolic mirror
situated in the rear end of the tube. This reflects them forwards to a
focus. In the Newtonian reflector a plane mirror or prism is situated in
the axis of the tube, at the focus, to reflect the rays through an
eye-piece projecting through the side of the tube. Herschel's form of
reflector has the mirror set at an angle to the axis, so that the rays
are reflected direct into an eye-piece pointing through the side of the
tube towards the mirror.


THE PARABOLIC MIRROR.

This mirror (Fig. 128) is of such a shape that all rays parallel to the
axis are reflected to a common point. In the marine searchlight a
powerful arc lamp is arranged with the arc at the focus of a parabolic
reflector, which sends all reflected light forward in a pencil of
parallel rays. The most powerful searchlight in existence gives a light
equal to that of 350 million candles.

[Illustration: FIG. 128.--A parabolic reflector.]


THE COMPOUND MICROSCOPE.

We have already observed (Fig. 110) that the nearer an object
approaches a lens the further off behind it is the real image formed,
until the object has reached the focal distance, when no image at all is
cast, as it is an infinite distance behind the lens. We will assume that
a certain lens has a focus of six inches. We place a lighted candle four
feet in front of it, and find that a _sharp_ diminished image is cast on
a ground-glass screen held seven inches behind it. If we now exchange
the positions of the candle and the screen, we shall get an enlarged
image of the candle. This is a simple demonstration of the law of
_conjugate foci_--namely, that the distance between the lens and an
object on one side and that between the lens and the corresponding image
on the other bear a definite relation to each other; and an object
placed at either focus will cast an image at the other. Whether the
image is larger or smaller than the object depends on which focus it
occupies. In the case of the object-glass of a telescope the image was
at what we may call the _short_ focus.

[Illustration: FIG. 129.--Diagram to explain the compound microscope.]

Now, a compound microscope is practically a telescope with the object at
the _long_ focus, very close to a short-focus lens. A greatly enlarged
image is thrown (see Fig. 129) at the conjugate focus, and this is
caught and still further magnified by the eye-piece. We may add that the
object-glass, or _objective_, of a microscope is usually compounded of
several lenses, as is also the eye-piece.


THE MAGIC-LANTERN.

The most essential features of a magic-lantern are:--(1) The _source of
light_; (2) the _condenser_ for concentrating the light rays on to the
slide; (3) the _lens_ for projecting a magnified image on to a screen.

Fig. 130 shows these diagrammatically. The _illuminant_ is most commonly
an oil-lamp, or an acetylene gas jet, or a cylinder of lime heated to
intense luminosity by an oxy-hydrogen flame. The natural combustion of
hydrogen is attended by a great heat, and when the supply of oxygen is
artificially increased the temperature of the flame rises enormously.
The nozzle of an oxy-hydrogen jet has an interior pipe connected with
the cylinder holding one gas, and an exterior, and somewhat larger, pipe
leading from that containing the other, the two being arranged
concentrically at the nozzle. By means of valves the proportions of the
gases can be regulated to give the best results.

[Illustration: FIG. 130.--Sketch of the elements of a magic-lantern.]

The _condenser_ is set somewhat further from the illuminant than the
principal focal length of the lenses, so that the rays falling on them
are bent inwards, or to the slide.

The _objective_, or object lens, stands in front of the slide. Its
position is adjustable by means of a rack and a draw-tube. The nearer it
is brought to the slide the further away is the conjugate focus (see p.
239), and consequently the image. The exhibitor first sets up his screen
and lantern, and then finds the conjugate foci of slide and image by
racking the lens in or out.

If a very short focus objective be used, subjects of microscopic
proportions can be projected on the screen enormously magnified. During
the siege of Paris in 1870-71 the Parisians established a balloon and
pigeon post to carry letters which had been copied in a minute size by
photography. These copies could be enclosed in a quill and attached to a
pigeon's wing. On receipt, the copies were placed in a special lantern
and thrown as large writing on the screen. Micro-photography has since
then made great strides, and is now widely used for scientific purposes,
one of the most important being the study of the crystalline formations
of metals under different conditions.


THE BIOSCOPE.

"Living pictures" are the most recent improvement in magic-lantern
entertainments. The negatives from which the lantern films are printed
are made by passing a ribbon of sensitized celluloid through a special
form of camera, which feeds the ribbon past the lens in a series of
jerks, an exposure being made automatically by a revolving shutter
during each rest. The positive film is placed in a lantern, and the
intermittent movement is repeated; but now the source of illumination is
behind the film, and light passes outwards through the shutter to the
screen. In the Urban bioscope the film travels at the rate of fifteen
miles an hour, upwards of one hundred exposures being made every second.

The impression of continuous movement arises from the fact that the eye
cannot get rid of a visual impression in less than one-tenth of a
second. So that if a series of impressions follow one another more
rapidly than the eye can rid itself of them the impressions will
overlap, and give one of _motion_, if the position of some of the
objects, or parts of the objects, varies slightly in each succeeding
picture.[25]


THE PLANE MIRROR.

[Illustration: FIG. 131.]

This chapter may conclude with a glance at the common looking-glass. Why
do we see a reflection in it? The answer is given graphically by Fig.
131. Two rays, A _b_, A _c_, from a point A strike the mirror M at the
points _b_ and _c_. Lines _b_ N, _c_ O, drawn from these points
perpendicular to the mirror are called their _normals_. The angles A
_b_ N, A _c_ O are the _angles of incidence_ of rays A _b_, A _c_. The
paths which the rays take after reflection must make angles with _b_ N
and _c_ O respectively equal to A _b_ N, A _c_ O. These are the _angles
of reflection_. If the eye is so situated that the rays enter it as in
our illustration, an image of the point A is seen at the point A^1, in
which the lines D _b_, E _c_ meet when produced backwards.

[Illustration: FIG. 132.]

When the vertical mirror is replaced by a horizontal reflecting surface,
such as a pond (Fig. 132), the same thing happens. The point at which
the ray from the reflection of the spire's tip to the eye appears to
pass through the surface of the water must be so situated that if a line
were drawn perpendicular to it from the surface the angles made by lines
drawn from the real spire tip and from the observer's eye to the base of
the perpendicular would be equal.


[22] Glazebrook, "Light," p. 157.

[23] Glazebrook, "Light," p. 157.

[24] Galileo was severely censured and imprisoned for daring to maintain
that the earth moved round the sun, and revolved on its axis.

[25] For a full account of Animated Pictures the reader might
advantageously consult "The Romance of Modern Invention," pp. 166 foll.




Chapter XIV.

SOUND AND MUSICAL INSTRUMENTS.

     Nature of sound--The ear--Musical instruments--The vibration of
     strings--The sounding-board and the frame of a piano--The
     strings--The striking mechanism--The quality of a note.


Sound differs from light, heat, and electricity in that it can be
propagated through matter only. Sound-waves are matter-waves, not
ether-waves. This can be proved by placing an electric bell under the
bell-glass of an air-pump and exhausting all the air. Ether still
remains inside the glass, but if the bell be set in motion no sound is
audible. Admit air, and the clang of the gong is heard quite plainly.

Sound resembles light and heat, however, thus far, that it can be
concentrated by means of suitable lenses and curved surfaces. An _echo_
is a proof of its _reflection_ from a surface.

Before dealing with the various appliances used for producing
sound-waves of a definite character, let us examine that wonderful
natural apparatus


THE EAR,

through which we receive those sensations which we call sound.

[Illustration: FIG. 133.--Diagrammatic sketch of the parts of the ear.]

Fig. 133 is a purely diagrammatic section of the ear, showing the
various parts distorted and out of proportion. Beginning at the left, we
have the _outer ear_, the lobe, to gather in the sound-waves on to the
membrane of the tympanum, or drum, to which is attached the first of a
series of _ossicles_, or small bones. The last of these presses against
an opening in the _inner ear_, a cavity surrounded by the bones of the
head. Inside the inner ear is a watery fluid, P, called _perilymph_
("surrounding water"), immersed in which is a membranic envelope, M,
containing _endolymph_ ("inside water"), also full of fluid. Into this
fluid project E E E, the terminations of the _auditory nerve_, leading
to the brain.

When sound-waves strike the tympanum, they cause it to move inwards and
outwards in a series of rapid movements. The ossicles operated by the
tympanum press on the little opening O, covered by a membrane, and every
time they push it in they slightly squeeze the perilymph, which in turn
compresses the endolymph, which affects the nerve-ends, and telegraphs a
sensation of sound to the brain.

In Fig. 134 we have a more developed sketch, giving in fuller detail,
though still not in their actual proportions, the components of the ear.
The ossicles M, I, and S are respectively the _malleus_ (hammer),
_incus_ (anvil), and _stapes_ (stirrup). Each is attached by ligaments
to the walls of the middle ear. The tympanum moves the malleus, the
malleus the incus, and the incus the stapes, the last pressing into the
opening O of Fig. 133, which is scientifically known as the _fenestra
ovalis_, or oval window. As liquids are practically incompressible,
nature has made allowance for the squeezing in of the oval window
membrane, by providing a second opening, the round window, also covered
with a membrane. When the stapes pushes the oval membrane in, the round
membrane bulges out, its elasticity sufficing to put a certain pressure
on the perilymph (indicated by the dotted portion of the inner ear).

[Illustration: FIG. 134.--Diagrammatic section of the ear, showing the
various parts.]

The inner ear consists of two main parts, the _cochlea_--so called from
its resemblance in shape to a snail's shell--and the _semicircular
canals_. Each portion has its perilymph and endolymph, and contains a
number of the nerve-ends, which are, however, most numerous in the
cochlea. We do not know for certain what the functions of the canals and
the cochlea are; but it is probable that the former enables us to
distinguish between the _intensity_ or loudness of sounds and the
direction from which they come, while the latter enables us to determine
the _pitch_ of a note. In the cochlea are about 2,800 tiny nerve-ends,
called the _rods of Corti_. The normal ear has such a range as to give
about 33 rods to the semitone. The great scientist Helmholtz has
advanced the theory that these little rods are like tiny tuning-forks,
each responding to a note of a certain pitch; so that when a string of a
piano is sounded and the air vibrations are transmitted to the inner
ear, they affect only one of these rods and the part of the brain which
it serves, and we have the impression of one particular note. It has
been proved by experiment that a very sensitive ear can distinguish
between sounds varying in pitch by only 1/64th of a semitone, or but
half the range of any one Corti fibre. This difficulty Helmholtz gets
over by suggesting that in such an ear two adjacent fibres are affected,
but one more than the other.

A person who has a "good ear" for music is presumably one whose Corti
rods are very perfect. Unlucky people like the gentleman who could only
recognize one tune, and that because people took off their hats when it
commenced, are physically deficient. Their Corti rods cannot be properly
developed.

What applies to one single note applies also to the elements of a
musical chord. A dozen notes may sound simultaneously, but the ear is
able to assimilate each and blend it with its fellows; yet it requires a
very sensitive and well-trained ear to pick out any one part of a
harmony and concentrate the brain's attention on that part.

The ear has a much larger range than the eye. "While the former ranges
over eleven octaves, but little more than a single octave is possible to
the latter. The quickest vibrations which strike the eye, as light, have
only about twice the rapidity of the slowest; whereas the quickest
vibrations which strike the ear, as a musical sound, have more than two
thousand times the rapidity of the slowest."[26] To come to actual
figures, the ordinary ear is sensitive to vibrations ranging from 16 to
38,000 per second. The bottom and top notes of a piano make respectively
about 40 and 4,000 vibrations a second. Of course, some ears, like some
eyes, cannot comprehend the whole scale. The squeak of bats and the
chirrup of crickets are inaudible to some people; and dogs are able to
hear sounds far too shrill to affect the human auditory apparatus.

Not the least interesting part of this wonderful organ is the tympanic
membrane, which is provided with muscles for altering its tension
automatically. If we are "straining our ears" to catch a shrill sound,
we tighten the membrane; while if we are "getting ready" for a deep,
loud report like that of a gun, we allow the drum to slacken.

The _Eustachian tube_ (Fig. 134) communicates with the mouth. Its
function is probably to keep the air-pressure equal on both sides of the
drum. When one catches cold the tube is apt to become blocked by mucus,
causing unequal pressure and consequent partial deafness.

Before leaving this subject, it will be well to remind our more youthful
readers that the ear is delicately as well as wonderfully made, and must
be treated with respect. Sudden shouting into the ear, or a playful
blow, may have most serious effects, by bursting the tympanum or
injuring the arrangement of the tiny bones putting it in communication
with the inner ear.


MUSICAL INSTRUMENTS.

These are contrivances for producing sonorous shocks following each
other rapidly at regular intervals. Musical sounds are distinguished
from mere noises by their regularity. If we shake a number of nails in a
tin box, we get only a series of superimposed and chaotic sensations. On
the other hand, if we strike a tuning-fork, the air is agitated a
certain number of times a second, with a pleasant result which we call a
note.

We will begin our excursion into the region of musical instruments with
an examination of that very familiar piece of furniture,


THE PIANOFORTE,

which means literally the "soft-strong." By many children the piano is
regarded as a great nuisance, the swallower-up of time which could be
much more agreeably occupied, and is accordingly shown much less respect
than is given to a phonograph or a musical-box. Yet the modern piano is
a very clever piece of work, admirably adapted for the production of
sweet melody--if properly handled. The two forms of piano now generally
used are the _upright_, with vertical sound-board and wires, and the
_grand_, with horizontal sound-board.[27]


THE VIBRATION OF STRINGS.

As the pianoforte is a stringed instrument, some attention should be
given to the subject of the vibration of strings. A string in a state of
tension emits a note when plucked and allowed to vibrate freely. The
_pitch_ of the note depends on several conditions:--(1) The diameter of
the string; (2) the tension of the string; (3) the length of the string;
(4) the substance of the string. Taking them in order:--(1.) The number
of vibrations per second is inversely proportional to the diameter of
the string: thus, a string one-quarter of an inch in diameter would
vibrate only half as often in a given time as a string one-eighth of an
inch in diameter. (2.) The length remaining the same, the number of
vibrations is directly proportional to the _square root_ of the
_tension_: thus, a string strained by a 16-lb. weight would vibrate four
times as fast as it would if strained by a 1-lb. weight. (3.) The number
of vibrations is inversely proportional to the _length_ of the string:
thus, a one-foot string would vibrate twice as fast as a two-foot
string, strained to the same tension, and of equal diameter and weight.
(4.) Other things being equal, the rate of vibration is inversely
proportional to the square root of the _density_ of the substance: so
that a steel wire would vibrate more rapidly than a platinum wire of
equal diameter, length, and tension. These facts are important to
remember as the underlying principles of stringed instruments.

Now, if you hang a wire from a cord, and hang a heavy weight from the
wire, the wire will be in a state of high tension, and yield a distinct
note if struck. But the volume of sound will be very small, much too
small for a practical instrument. The surface of the string itself is so
limited that it sets up but feeble motions in the surrounding air. Now
hang the wire from a large board and strike it again. The volume of
sound has greatly increased, because the string has transmitted its
vibrations to the large surface of the board.

To get the full sound-value of the vibrations of a string, we evidently
ought to so mount the string that it may influence a large sounding
surface. In a violin this is effected by straining the strings over a
"bridge" resting on a hollow box made of perfectly elastic wood. Draw
the bow across a string. The loud sound heard proceeds not from the
string only, but also from the whole surface of the box.


THE SOUNDING-BOARD AND FRAME OF A PIANO.

A piano has its strings strained across a _frame_ of wood or steel, from
a row of hooks in the top of the frame to a row of tapering square-ended
pins in the bottom, the wires passing over sharp edges near both ends.
The tuner is able, on turning a pin, to tension its strings till it
gives any desired note. Readers may be interested to learn that the
average tension of a string is 275 lbs., so that the total strain on the
frame of a grand piano is anything between 20 and 30 _tons_.

To the back of the frame is attached the _sounding-board_, made of
spruce fir (the familiar Christmas tree). This is obtained from Central
and Eastern Europe, where it is carefully selected and prepared, as it
is essential that the timber should be sawn in such a way that the grain
of the wood runs in the proper direction.


THE STRINGS.

These are made of extremely strong steel wire of the best quality. If
you examine the wires of your piano, you will see that they vary in
thickness, the thinnest being at the treble end of the frame. It is
found impracticable to use wires of the same gauge and the same tension
throughout. The makers therefore use highly-tensioned thick wires for
the bass, and finer, shorter wires for the treble, taking advantage of
the three factors--weight, tension, and length--which we have noticed
above. The wires for the deepest notes are wrapped round with fine
copper wire to add to their weight without increasing their diameter at
the tuning-pins. There are about 600 yards (roughly one-third of a mile)
of wire in a grand piano.


THE STRIKING MECHANISM.

We now pass to the apparatus for putting the strings in a state of
vibration. The grand piano mechanism shown in Fig. 135 may be taken as
typical of the latest improvements. The essentials of an effective
mechanism are:--(1) That the blow delivered shall be sharp and certain;
(2) that the string shall be immediately "damped," or have its vibration
checked if required, so as not to interfere with the succeeding notes of
other strings; (3) that the hammer shall be able to repeat the blows in
quick succession. The _hammer_ has a head of mahogany covered with
felt, the thickness of which tapers gradually and regularly from an inch
and a quarter at the bass end to three-sixteenths of an inch at the
extreme treble notes. The entire eighty-five hammers for the piano are
covered all together in one piece, and then they are cut apart from
each other. The consistency of the covering is very important. If too
hard, it yields a harsh note, and must be reduced to the right degree by
pricking with a needle. In the diagram the felt is indicated by the
dotted part.

[Illustration: FIG. 135.--The striking mechanism of a "grand" piano.]

The _action carriage_ which operates the hammer is somewhat complicated.
When the key is depressed, the left end rises, and pushes up the whole
carriage, which is pivoted at one end. The hammer shank is raised by the
jack B pressing upon a knob, N, called the _notch_, attached to the
under side of the shank. When the jack has risen to a certain point, its
arm, B^1, catches against the button C and jerks it from under the
notch at the very moment when the hammer strikes, so that it may not be
blocked against the string. As it rebounds, the hammer is caught on the
_repetition lever_ R, which lifts it to allow of perfect repetition.

The _check_ catches the tail of the hammer head during its descent when
the key is raised, and prevents it coming back violently on the carriage
and rest. The tail is curved so as to wedge against the check without
jamming in any way. The moment the carriage begins to rise, the rear end
of the key lifts a lever connected with the _damper_ by a vertical
wire, and raises the damper of the string. If the key is held down, the
vibrations continue for a long time after the blow; but if released at
once, the damper stifles them as the hammer regains its seat. A bar, L,
passing along under all the _damper lifters_, is raised by depressing
the loud pedal. The _soft pedal_ slides the whole keyboard along such a
distance that the hammers strike two only out of the three strings
allotted to all except the bass notes, which have only one string
apiece, or two, according to their depth or length. In some pianos the
soft pedal presses a special damper against the strings; and a third
kind of device moves the hammers nearer the strings so that they deliver
a lighter blow. These two methods of damping are confined to upright
pianos.

A high-class piano is the result of very careful workmanship. The
mechanism of each note must be accurately regulated by its tiny screws
to a minute fraction of an inch. It must be ensured that every hammer
strikes its blow at exactly the right place on the string, since on this
depends the musical value of the note. The adjustment of the dampers
requires equal care, and the whole work calls for a sensitive ear
combined with skilled mechanical knowledge, so that the instrument may
have a light touch, strength, and certainty of action throughout the
whole keyboard.


THE QUALITY OF A NOTE.

If two strings, alike in all respects and equally tensioned, are
plucked, both will give the same note, but both will not necessarily
have the same quality of tone. The quality, or _timbre_, as musicians
call it, is influenced by the presence of _overtones_, or _harmonics_,
in combination with the _fundamental_, or deepest, tone of the string.
The fact is, that while a vibrating string vibrates as a whole, it also
vibrates in parts. There are, as it were, small waves superimposed on
the big fundamental waves. Points of least motion, called _nodes_, form
on the string, dividing it into two, three, four, five, etc., parts,
which may be further divided by subsidiary nodes. The string, considered
as halved by one node, gives the first overtone, or octave of the
fundamental. It may also vibrate as three parts, and give the second
overtone, or twelfth of the fundamental;[28] and as four parts, and give
the third overtone, the double octave.

Now, if a string be struck at a point corresponding to a node, the
overtones which require that point for a node will be killed, on account
of the excessive motion imparted to the string at that spot. Thus to hit
it at the middle kills the octave, the double octave, etc.; while to hit
it at a point one-third of the length from one end stifles the twelfth
and all its sub-multiples.

A fundamental note robbed of all its harmonics is hard to obtain, which
is not a matter for regret, as it is a most uninteresting sound. To get
a rich tone we must keep as many useful harmonics as possible, and
therefore a piano hammer is so placed as to strike the string at a point
which does not interfere with the best harmonics, but kills those which
are objectionable. Pianoforte makers have discovered by experiment that
the most pleasing tone is excited when the point against which the
hammer strikes is one-seventh to one-ninth of the length of the wire
from one end.

The nature of the material which does the actual striking is also of
importance. The harder the substance, and the sharper the blow, the more
prominent do the harmonics become; so that the worker has to regulate
carefully both the duration of the blow and the hardness of the hammer
covering.


[26] Tyndall, "On Sound," p. 75.

[27] A Broadwood "grand" is made up of 10,700 separate pieces, and in
its manufacture forty separate trades are concerned.

[28] Twelve notes higher up the scale.




Chapter XV.

WIND INSTRUMENTS.

     Longitudinal vibration--Columns of air--Resonance of columns of
     air--Length and tone--The open pipe--The overtones of an open
     pipe--Where overtones are used--The arrangement of the pipes and
     pedals--Separate sound-boards--Varieties of stops--Tuning pipes and
     reeds--The bellows--Electric and pneumatic actions--The largest
     organ in the world--Human reeds.


LONGITUDINAL VIBRATION.

In stringed instruments we are concerned only with the transverse
vibrations of a string--that is, its movements in a direction at right
angles to the axis of the string. A string can also vibrate
longitudinally--that is, in the direction of its axis--as may be proved
by drawing a piece of resined leather along a violin string. In this
case the harmonics "step up" at the same rate as when the movements were
transverse.

Let us substitute for a wire a stout bar of metal fixed at one end only.
The longitudinal vibrations of this rod contain overtones of a different
ratio. The first harmonic is not an octave, but a twelfth. While a
tensioned string is divided by nodes into two, three, four, five, six,
etc., parts, a rod fixed at one end only is capable of producing only
those harmonics which correspond to division into three, five, seven,
nine, etc., parts. Therefore a free-end rod and a wire of the same
fundamental note would not have the same _timbre_, or quality, owing to
the difference in the harmonics.


COLUMNS OF AIR.

In wind instruments we employ, instead of rods or wires, columns of air
as the vibrating medium. The note of the column depends on its length.
In the "penny whistle," flute, clarionet, and piccolo the length of the
column is altered by closing or opening apertures in the substance
encircling the column.


RESONANCE OF COLUMNS OF AIR.

Why does a tube closed at one end, such as the shank of a key, emit a
note when we blow across the open end? The act of blowing drives a thin
sheet of air against the edge of the tube and causes it to vibrate. The
vibrations are confused, some "pulses" occurring more frequently than
others. If we blew against the edge of a knife or a piece of wood, we
should hear nothing but a hiss. But when, as in the case which we are
considering, there is a partly-enclosed column of air close to the
pulses, this selects those pulses which correspond to its natural period
of vibration, and augments them to a sustained and very audible musical
sound.

[Illustration: FIG 136.--Showing how the harmonics of a "stopped" pipe
are formed.]

In Fig. 136, _1_ is a pipe, closed at the bottom and open at the top. A
tuning-fork of the same note as the pipe is struck and held over it so
that the prongs vibrate upwards and downwards. At the commencement of an
outward movement of the prongs the air in front of them is _compressed_.
This impulse, imparted to the air in the pipe, runs down the column,
strikes the bottom, and returns. Just as it reaches the top the prong is
beginning to move inwards, causing a _rarefaction_ of the air behind
it. This effect also travels down and back up the column of air in the
pipe, reaching the prong just as it arrives at the furthest point of the
inward motion. The process is repeated, and the column of air in the
pipe, striking on the surrounding atmosphere at regular intervals,
greatly increases the volume of sound. We must observe that if the
tuning-fork were of too high or too low a note for the column of air to
move in perfect sympathy with it, this increase of sound would not
result. Now, when we blow across the end, we present, as it were, a
number of vibrating tuning-forks to the pipe, which picks out those
air-pulses with which it sympathizes.


LENGTH AND TONE.

The rate of vibration is found to be inversely proportional to the
length of the pipe. Thus, the vibrations of a two-foot pipe are twice as
rapid as those of a four-foot pipe, and the note emitted by the former
is an octave higher than that of the latter. A one-foot pipe gives a
note an octave higher still. We are here speaking of the _fundamental_
tones of the pipes. With them, as in the case of strings, are associated
the _overtones_, or harmonics, which can be brought into prominence by
increasing the pressure of the blast at the top of the pipe. Blow very
hard on your key, and the note suddenly changes to one much shriller. It
is the twelfth of the fundamental, of which it has completely got the
upper hand.

We must now put on our thinking-caps and try to understand how this
comes about. First, let us note that the vibration of a body (in this
case a column of air) means a motion from a point of rest to a point of
rest, or from node to node. In the air-column in Fig. 136, _1_, there is
only one point of rest for an impulse--namely, at the bottom of the
pipe. So that to pass from node to node the impulse must pass up the
pipe and down again. The distance from node to node in a vibrating body
is called a _ventral segment_. Remember this term. Therefore the pipe
represents a semi-ventral segment when the fundamental note is sounding.

When the first overtone is sounded the column divides itself into two
vibrating parts. Where will the node between them be? We might naturally
say, "Half-way up." But this cannot be so; for if the node were so
situated, an impulse going down the pipe would only have to travel to
the bottom to find another node, while an impulse going up would have
to travel to the top and back again--that is, go twice as far. So the
node forms itself _one-third_ of the distance down the pipe. From B to A
(Fig. 136, _2_) and back is now equal to from B to C. When the second
overtone is blown (Fig. 136, _3_) a third node forms. The pipe is now
divided into _five_ semi-ventral segments. And with each succeeding
overtone another node and ventral segment are added.

The law of vibration of a column of air is that the number of vibrations
is directly proportional to the number of semi-ventral segments into
which the column of air inside the pipe is divided.[29] If the
fundamental tone gives 100 vibrations per second, the first overtone in
a closed pipe must give 300, and the second 500 vibrations.


THE OPEN PIPE.

A pipe open at both ends is capable of emitting a note. But we shall
find, if we experiment, that the note of a stopped pipe is an octave
lower than that of an open pipe of equal length. This is explained by
Fig. 137, _1_. The air-column in the pipe (of the same length as that in
Fig. 136) divides itself, when an end is blown across, into two equal
portions at the node B, the natural point to obtain equilibrium. A pulse
will pass from A or A^1 to B and back again in half the time required
to pass from A to B and back in Fig. 136, _1_; therefore the note is an
octave higher.

[Illustration: FIG. 137.--Showing how harmonics of an open pipe are
formed, B, B^1, and C are "nodes." The arrows indicate the distance
travelled by a sound impulse from a node to a node.]


THE OVERTONES OF AN OPEN PIPE.

The first overtone results when nodes form as in Fig. 137, _2_, at
points one-quarter of the length of the pipe from the ends, giving one
complete ventral segment and two semi-ventral segments. The vibrations
now are twice as rapid as before. The second overtone requires three
nodes, as in Fig. 137, _3_. The rate has now trebled. So that, while
the overtones of a closed pipe rise in the ratio 1, 3, 5, 7, etc.,
those of an open pipe rise in the proportion 1, 2, 3, 4, etc.


WHERE OVERTONES ARE USED.

In the flute, piccolo, and clarionet, as well as in the horn class of
instrument, the overtones are as important as the fundamental notes. By
artificially altering the length of the column of air, the fundamental
notes are also altered, while the harmonics of each fundamental are
produced at will by varying the blowing pressure; so that a continuous
chromatic, or semitonal, scale is possible throughout the compass of the
instrument.


THE ORGAN.

From the theory of acoustics[30] we pass to the practical application,
and concentrate our attention upon the grandest of all wind instruments,
the pipe organ. This mechanism has a separate pipe for every note,
properly proportioned. A section of an ordinary wooden pipe is given in
Fig. 138. Wind rushes up through the foot of the pipe into a little
chamber, closed by a block of wood or a plate except for a narrow slit,
which directs it against the sharp lip A, and causes a fluttering, the
proper pulse of which is converted by the air-column above into a
musical sound.

[Illustration: FIG. 138.--Section of an ordinary wooden "flue" pipe.]

In even the smallest organs more than one pipe is actuated by one key on
the keyboard, for not only do pipes of different shapes give different
qualities of tone, but it is found desirable to have ranks of pipes with
their bottom note of different pitches. The length of an open pipe is
measured from the edge of the lip to the top of the pipe; of a stopped
pipe, from the lip to the top and back again. When we speak of a 16 or 8
foot rank, or stop, we mean one of which the lowest note in the rank is
that produced by a 16 or 8 foot open pipe, or their stopped equivalents
(8 or 4 foot). In a big organ we find 32, 16, 8, 4, and 2 foot stops,
and some of these repeated a number of times in pipes of different shape
and construction.


THE ARRANGEMENT OF THE PIPES.

We will now study briefly the mechanism of a very simple single-keyboard
organ, with five ranks of pipes, or stops.

[Illustration: FIG. 139.--The table of a sound-board.]

It is necessary to arrange matters so that the pressing down of one key
may make all five of the pipes belonging to it speak, or only four,
three, two, or one, as we may desire. The pipes are mounted in rows on a
_sound-board_, which is built up in several layers. At the top is the
_upper board_; below it come the _sliders_, one for each stop; and
underneath that the _table_. In Fig. 139 we see part of the table from
below. Across the under side are fastened parallel bars with spaces
(shown black) left between them. Two other bars are fastened across the
ends, so that each groove is enclosed by wood at the top and on all
sides. The under side of the table has sheets of leather glued or
otherwise attached to it in such a manner that no air can leak from one
groove to the next. Upper board, sliders, and table are pierced with
rows of holes, to permit the passage of wind from the grooves to the
pipes. The grooves under the big pipes are wider than those under the
small pipes, as they have to pass more air. The bars between the grooves
also vary in width according to the weight of the pipes which they have
to carry. The sliders can be moved in and out a short distance in the
direction of the axis of the rows of pipes. There is one slider under
each row. When a slider is in, the holes in it do not correspond with
those in the table and upper board, so that no wind can get from the
grooves to the rank over that particular slider. Fig. 140 shows the
manner in which the sliders are operated by the little knobs (also
called stops) projecting from the casing of the organ within convenient
reach of the performer's hands. One stop is in, the other drawn out.

[Illustration: FIG. 140.]

In Fig. 141 we see the table, etc., in cross section, with a slider out,
putting the pipes of its rank in communication with the grooves. The
same diagram shows us in section the little triangular _pallets_ which
admit air from the _wind-chest_ to the grooves; and Fig. 142 gives us an
end section of table, sliders, and wind-chest, together with the rods,
etc., connecting the key to its pallet. When the key is depressed, the
_sticker_ (a slight wooden rod) is pushed up. This rocks a _backfall_,
or pivoted lever, to which is attached the _pulldown_, a wire
penetrating the bottom of the wind-chest to the pallet. As soon as the
pallet opens, wind rushes into the groove above through the aperture in
the leather bottom, and thence to any one of the pipes of which the
slider has been drawn out. (The sliders in Fig. 142 are solid black.) It
is evident that if the sound-board is sufficiently deep from back to
front, any number of rows of pipes may be placed on it.

[Illustration: FIG. 141.]


PEDALS.

The organ pedals are connected to the pallets by an action similar to
that of the keys. The pedal stops are generally of deep tone, 32-foot
and 16-foot, as they have to sustain the bass part of the musical
harmonies. By means of _couplers_ one or more of the keyboard stops may
be linked to the pedals.


SEPARATE SOUND-BOARDS.

The keyboard of a very large organ has as many as five _manuals_, or
rows of keys. Each manual operates what is practically a separate organ
mounted on its own sound-board.

[Illustration: FIG. 142.]

[Illustration: FIG. 143.--General section of a two-manual organ.]

The manuals are arranged in steps, each slightly overhanging that
below. Taken in order from the top, they are:--(1.) _Echo organ_, of
stops of small scale and very soft tone, enclosed in a "swell-box." (2.)
_Solo organ_, of stops imitating orchestral instruments. The wonderful
"vox humana" stop also belongs to this manual. (3.) _Swell organ_,
contained in a swell-box, the front and sides of which have shutters
which can be opened and closed by the pressure of the foot on a lever,
so as to regulate the amount of sound proceeding from the pipes inside.
(4.) _Great organ_, including pipes of powerful tone. (5.) _Choir
organ_, of soft, mellow stops, often enclosed in a swell-box. We may add
to these the _pedal organ_, which can be coupled to any but the echo
manual.


VARIETIES OF STOPS.

We have already remarked that the quality of a stop depends on the shape
and construction of the pipe. Some pipes are of wood, others of metal.
Some are rectangular, others circular. Some have parallel sides, others
taper or expand towards the top. Some are open, others stopped.

The two main classes into which organ pipes may be divided are:--(1.)
_Flue_ pipes, in which the wind is directed against a lip, as in Fig.
138. (2.) _Reed_ pipes--that is, pipes used in combination with a
simple device for admitting air into the bottom of the pipe in a series
of gusts. Fig. 144 shows a _striking_ reed, such as is found in the
ordinary motor horn. The elastic metal tongue when at rest stands a very
short distance away from the orifice in the reed. When wind is blown
through the reed the tongue is sucked against the reed, blocks the
current, and springs away again. A _free_ reed has a tongue which
vibrates in a slot without actually touching the sides. Harmonium and
concertina reeds are of this type. In the organ the reed admits air to a
pipe of the correct length to sympathize with the rate of the puffs of
air which the reed passes. Reed pipes expand towards the top.


TUNING PIPES AND REEDS.

[Illustration: FIG. 144.--A reed pipe.]

Pipes are tuned by adjusting their length. The plug at the top of a
stopped pipe is pulled out or pushed in a trifle to flatten or sharpen
the note respectively. An open pipe, if large, has a tongue cut in the
side at the top, which can be pressed inwards or outwards for the
purpose of correcting the tone. Small metal pipes are flattened by
contracting the tops inwards with a metal cone like a
candle-extinguisher placed over the top and tapped; and sharpened by
having the top splayed by a cone pushed in point downwards. Reeds of the
striking variety (see Fig. 144) have a tuning-wire pressing on the
tongue near the fixed end. The end of this wire projects through the
casing. By moving it, the length of the vibrating part of the tongue is
adjusted to correctness.


BELLOWS.

Different stops require different wind-pressures, ranging from 1/10 lb.
to 1 lb. to the square inch, the reeds taking the heaviest pressures.
There must therefore be as many sets of bellows and wind-chests as there
are different pressures wanted. A very large organ consumes immense
quantities of air when all the stops are out, and the pumping has to be
done by a powerful gas, water, or electric engine. Every bellows has a
reservoir (see Fig. 143) above it. The top of this is weighted to give
the pressure required. A valve in the top opens automatically as soon as
the reservoir has expanded to a certain fixed limit, so that there is no
possibility of bursting the leather sides.

[Illustration: FIG. 145.--The keyboard and part of the pneumatic
mechanism of the Hereford Cathedral organ. C, composition pedals for
pushing out groups of stops; P (at bottom), pedals; P P (at top), pipes
carrying compressed air; M, manuals (4); S S, stops.]


ELECTRIC AND PNEUMATIC ACTIONS.

We have mentioned in connection with railway signalling that the
signalman is sometimes relieved of the hard manual labour of moving
signals and points by the employment of electric and pneumatic
auxiliaries. The same is true of organs and organists. The touch of the
keys has been greatly lightened by making the keys open air-valves or
complete electric circuits which actuate the mechanism for pulling down
the pallets. The stops, pedals, and couplers also employ "power." Not
only are the performer's muscles spared a lot of heavy work when
compressed air and electricity aid him, but he is able to have the
_console_, or keyboard, far away from the pipes. "From the console, the
player, sitting with the singers, or in any desirable part of the choir
or chancel, would be able to command the working of the whole of the
largest organ situated afar at the western end of the nave; would draw
each stop in complete reliance on the sliders and the sound-board
fulfilling their office; ... and--marvel of it all--the player, using
the swell pedal in his ordinary manner, would obtain crescendo and
diminuendo with a more perfect effect than by the old way."[31]

In cathedrals it is no uncommon thing for the different sound-boards to
be placed in positions far apart, so that to the uninitiated there may
appear to be several independent organs scattered about. Yet all are
absolutely under the control of a man who is sitting away from them all,
but connected with them by a number of tubes or wires.

The largest organ in the world is that in the Town Hall, Sydney. It has
a hundred and twenty-six speaking stops, five manuals, fourteen
couplers, and forty-six combination studs. The pipes, about 8,000 in
number, range from the enormous 64-foot contra-trombone to some only a
fraction of an inch in length. The organ occupies a space 85 feet long
and 26 feet deep.


HUMAN REEDS.

The most wonderful of all musical reeds is found in the human throat, in
the anatomical part called the _larynx_, situated at the top of the
_trachea_, or windpipe.

Slip a piece of rubber tubing over the end of a pipe, allowing an inch
or so to project. Take the free part of the tube by two opposite points
between the first fingers and thumbs and pull it until the edges are
stretched tight. Now blow through it. The wind, forcing its way between
the two rubber edges, causes them and the air inside the tube to
vibrate, and a musical note results. The more you strain the rubber the
higher is the note.

The larynx works on this principle. The windpipe takes the place of the
glass pipe; the two vocal cords represent the rubber edges; and the
_arytenoid muscles_ stand instead of the hands. When contracted, these
muscles bring the edges of the cords nearer to one another, stretch the
cords, and shorten the cords. A person gifted with a "very good ear"
can, it has been calculated, adjust the length of the vocal cords to
1/17000th of an inch!

Simultaneously with the adjustment of the cords is effected the
adjustment of the length of the windpipe, so that the column of air in
it may be of the right length to vibrate in unison. Here again is seen a
wonderful provision of nature.

The resonance of the mouth cavity is also of great importance. By
altering the shape of the mouth the various harmonics of any fundamental
note produced by the larynx are rendered prominent, and so we get the
different vocal sounds. Helmholtz has shown that the fundamental tone of
any note is represented by the sound _oo_. If the mouth is adjusted to
bring out the octave of the fundamental, _o_ results. _a_ is produced by
accentuating the second harmonic, the twelfth; _ee_ by developing the
second and fourth harmonics; while for _ah_ the fifth and seventh must
be prominent.

When we whistle we transform the lips into a reed and the mouth into a
pipe. The tension of the lips and the shape of the mouth cavity decide
the note. The lips are also used as a reed for blowing the flute,
piccolo, and all the brass band instruments of the cornet order. In
blowing a coach-horn the various harmonics of the fundamental note are
brought out by altering the lip tension and the wind pressure. A cornet
is practically a coach-horn rolled up into a convenient shape and
furnished with three keys, the depression of which puts extra lengths of
tubing in connection with the main tube--in fact, makes it longer. One
key lowers the fundamental note of the horn half a tone; the second, a
full tone; the third, a tone and a half. If the first and third are
pressed down together, the note sinks two tones; if the second and
third, two and a half tones; and simultaneous depression of all three
gives a drop of three tones. The performer thus has seven possible
fundamental notes, and several harmonics of each of these at his
command; so that by a proper manipulation of the keys he can run up the
chromatic scale.

We should add that the cornet tube is an "open" pipe. So is that of the
flute. The clarionet is a "stopped" pipe.


[29] It is obvious that in Fig. 136, _2_, a pulse will pass from A to B
and back in one-third the time required for it to pass from A to B and
back in Fig. 136, _1_.

[30] The science of hearing; from the Greek verb, [Greek: akouein], "to
hear."

[31] "Organs and Tuning," p. 245.




Chapter XVI.

TALKING-MACHINES.

     The phonograph--The recorder--The reproducer--The gramophone--The
     making of records--Cylinder records--Gramophone records.


In the Patent Office Museum at South Kensington is a curious little
piece of machinery--a metal cylinder mounted on a long axle, which has
at one end a screw thread chased along it. The screw end rotates in a
socket with a thread of equal pitch cut in it. To the other end is
attached a handle. On an upright near the cylinder is mounted a sort of
drum. The membrane of the drum carries a needle, which, when the
membrane is agitated by the air-waves set up by human speech, digs into
a sheet of tinfoil wrapped round the cylinder, pressing it into a
helical groove turned on the cylinder from end to end. This construction
is the first phonograph ever made. Thomas Edison, the "wizard of the
West," devised it in 1876; and from this rude parent have descended the
beautiful machines which record and reproduce human speech and musical
sounds with startling accuracy.

[Illustration: FIG. 146.--The "governor" of a phonograph.]

We do not propose to trace here the development of the talking-machine;
nor will it be necessary to describe in detail its mechanism, which is
probably well known to most readers, or could be mastered in a very
short time on personal examination. We will content ourselves with
saying that the wax cylinder of the phonograph, or the ebonite disc of
the gramophone, is generally rotated by clockwork concealed in the body
of the machine. The speed of rotation has to be very carefully governed,
in order that the record may revolve under the reproducing point at a
uniform speed. The principle of the governor commonly used appears in
Fig. 146. The last pinion of the clockwork train is mounted on a shaft
carrying two triangular plates, A and C, to which are attached three
short lengths of flat steel spring with a heavy ball attached to the
centre of each. A is fixed; C moves up the shaft as the balls fly out,
and pulls with it the disc D, which rubs against the pad P (on the end
of a spring) and sets up sufficient friction to slow the clockwork. The
limit rate is regulated by screw S.


THE PHONOGRAPH.

Though the recording and reproducing apparatus of a phonograph gives
very wonderful results, its construction is quite simple. At the same
time, it must be borne in mind that an immense amount of experimenting
has been devoted to finding out the most suitable materials and forms
for the parts.

[Illustration: FIG. 147.--Section of an Edison Bell phonograph
recorder.]

The _recorder_ (Fig. 147) is a little circular box about one and a half
inches in diameter.[32] From the top a tube leads to the horn. The
bottom is a circular plate, C C, hinged at one side. This plate supports
a glass disc, D, about 1/150th of an inch thick, to which is attached
the cutting stylus--a tiny sapphire rod with a cup-shaped end having
very sharp edges. Sound-waves enter the box through the horn tube; but
instead of being allowed to fill the whole box, they are concentrated by
the shifting nozzle N on to the centre of the glass disc through the
hole in C C. You will notice that N has a ball end, and C C a socket to
fit N exactly, so that, though C C and N move up and down very rapidly,
they still make perfect contact. The disc is vibrated by the
sound-impulses, and drives the cutting point down into the surface of
the wax cylinder, turning below it in a clockwork direction. The only
dead weight pressing on S is that of N, C C, and the glass diaphragm.

[Illustration: FIG. 148.--Perspective view of a phonograph recorder.]

As the cylinder revolves, the recorder is shifted continuously along by
a leading screw having one hundred or more threads to the inch cut on
it, so that it traces a continuous helical groove from one end of the
wax cylinder to the other. This groove is really a series of very minute
indentations, not exceeding 1/1000th of an inch in depth.[33] Seen under
a microscope, the surface of the record is a succession of hills and
valleys, some much larger than others (Fig. 151, _a_). A loud sound
causes the stylus to give a vigorous dig, while low sounds scarcely move
it at all. The wonderful thing about this sound-recording is, that not
only are the fundamental tones of musical notes impressed, but also the
harmonics, which enable us to decide at once whether the record is one
of a cornet, violin, or banjo performance. Furthermore, if several
instruments are playing simultaneously near the recorder's horn, the
stylus catches all the different shades of tone of every note of a
chord. There are, so to speak, minor hills and valleys cut in the slopes
of the main hills and valleys.

[Illustration: FIG. 149.--Section of the reproducer of an Edison Bell
phonograph.]

[Illustration: FIG. 150.--Perspective view of a phonograph reproducer.]

The _reproducer_ (Fig. 149) is somewhat more complicated than the
recorder. As before, we have a circular box communicating with the horn
of the instrument. A thin glass disc forms a bottom to the box. It is
held in position between rubber rings, R R, by a screw collar, C. To the
centre is attached a little eye, from which hangs a link, L. Pivoted at
P from one edge of the box is a _floating weight_, having a circular
opening immediately under the eye. The link passes through this to the
left end of a tiny lever, which rocks on a pivot projecting from the
weight. To the right end of the lever is affixed a sapphire bar, or
stylus, with a ball end of a diameter equal to that of the cutting point
of the recorder. The floating weight presses the stylus against the
record, and also keeps the link between the rocking lever of the glass
diaphragm in a state of tension. Every blow given to the stylus is
therefore transmitted by the link to the diaphragm, which vibrates and
sends an air-impulse into the horn. As the impulses are given at the
same rate as those which agitated the diaphragm of the recorder, the
sounds which they represent are accurately reproduced, even to the
harmonics of a musical note.


THE GRAMOPHONE.

This effects the same purpose as the phonograph, but in a somewhat
different manner. The phonograph recorder digs vertically downwards into
the surface of the record, whereas the stylus of the gramophone wags
from side to side and describes a snaky course (Fig. 151_b_). It makes
no difference in talking-machines whether the reproducing stylus be
moved sideways or vertically by the record, provided that motion is
imparted by it to the diaphragm.

[Illustration: FIG. 151_a._]

[Illustration: FIG. 151_b._]

[Illustration: FIG. 151_c._--Section of a gramophone reproducer.]

In Fig. 151_c_ the construction of the gramophone reproducer is shown in
section. A is the cover which screws on to the bottom B, and confines
the diaphragm D between itself and a rubber ring. The portion B is
elongated into a tubular shape for connection with the horn, an arm of
which slides over the tube and presses against the rubber ring C to make
an air-tight joint. The needle-carrier N is attached at its upper end to
the centre of the diaphragm. At a point indicated by the white dot a pin
passes through it and the cover. The lower end is tubular to accommodate
the steel points, which have to be replaced after passing once over a
record. A screw, S, working in a socket projecting from the carrier,
holds the point fast. The record moves horizontally under the point in a
plane perpendicular to the page. The groove being zigzag, the needle
vibrates right and left, and rotating the carrier a minute fraction of
an inch on the pivot, shakes the glass diaphragm and sends waves of air
into the horn.

The gramophone is a reproducing instrument only. The records are made on
a special machine, fitted with a device for causing the recorder point
to describe a spiral course from the circumference to the centre of the
record disc. Some gramophone records have as many as 250 turns to the
inch. The total length of the tracing on a ten-inch "concert" record is
about 1,000 feet.


THE MAKING OF RECORDS.

For commercial purposes it would not pay to make every record separately
in a recording machine. The expense of employing good singers and
instrumentalists renders such a method impracticable. All the records we
buy are made from moulds, the preparation of which we will now briefly
describe.


CYLINDER, OR PHONOGRAPH RECORDS.

First of all, a wax record is made in the ordinary way on a recording
machine. After being tested and approved, it is hung vertically and
centrally from a rotating table pivoted on a vertical metal spike
passing up through the record. On one side of the table is a piece of
iron. On each side of the record, and a small distance away, rises a
brass rod enclosed in a glass tube. The top of the rods are hooked, so
that pieces of gold leaf may be suspended from them. A bell-glass is now
placed over the record, table, and rods, and the air is sucked out by a
pump. As soon as a good vacuum has been obtained, the current from the
secondary circuit of an induction coil is sent into the rods supporting
the gold leaves, which are volatilized by the current jumping from one
to the other. A magnet, whirled outside the bell-glass, draws round the
iron armature on the pivoted table, and consequently revolves the
record, on the surface of which a very thin coating of gold is
deposited. The record is next placed in an electroplating bath until a
copper shell one-sixteenth of an inch thick has formed all over the
outside. This is trued up on a lathe and encased in a brass tube. The
"master," or original wax record, is removed by cooling it till it
contracts sufficiently to fall out of the copper mould, on the inside
surface of which are reproduced, in relief, the indentations of the wax
"master."

Copies are made from the mould by immersing it in a tank of melted wax.
The cold metal chills the wax that touches it, so that the mould soon
has a thick waxen lining. The mould and copy are removed from the tank
and mounted on a lathe, which shapes and smooths the inside of the
record. The record is loosened from the mould by cooling. After
inspection for flaws, it is, if found satisfactory, packed in
cotton-wool and added to the saleable stock.

Gramophone master records are made on a circular disc of zinc, coated
over with a very thin film of acid-proof fat. When the disc is revolved
in the recording machine, the sharp stylus cuts through the fat and
exposes the zinc beneath. On immersion in a bath of chromic acid the
bared surfaces are bitten into, while the unexposed parts remain
unaffected. When the etching is considered complete, the plate is
carefully cleaned and tested. A negative copper copy is made from it by
electrotyping. This constitutes the mould. From it as many as 1,000
copies may be made on ebonite plates by combined pressure and heating.

[32] The Edison Bell phonograph is here referred to.

[33] Some of the sibilant or hissing sounds of the voice are computed to
be represented by depressions less than a millionth of an inch in depth.
Yet these are reproduced very clearly!




Chapter XVII.

WHY THE WIND BLOWS.

     Why the wind blows--Land and sea breezes--Light air and
     moisture--The barometer--The column barometer--The wheel
     barometer--A very simple barometer--The aneroid
     barometer--Barometers and weather--The diving-bell--The
     diving-dress--Air-pumps--Pneumatic tyres--The air-gun--The
     self-closing door-stop--The action of wind on oblique surfaces--The
     balloon--The flying-machine.


When a child's rubber ball gets slack through a slight leakage of air,
and loses some of its bounce, it is a common practice to hold it for a
few minutes in front of the fire till it becomes temporarily taut again.
Why does the heat have this effect on the ball? No more air has been
forced into the ball. After perusing the chapter on the steam-engine the
reader will be able to supply the answer. "Because the molecules of air
dash about more vigorously among one another when the air is heated, and
by striking the inside of the ball with greater force put it in a state
of greater tension."

If we heat an open jar there is no pressure developed, since the air
simply expands and flows out of the neck. But the air that remains in
the jar, being less in quantity than when it was not yet heated, weighs
less, though occupying the same space as before. If we took a very thin
bladder and filled it with hot air it would therefore float in colder
air, proving that heated air, as we should expect, _tends to rise_. The
fire-balloon employs this principle, the air inside the bag being kept
artificially warm by a fire burning in some vessel attached below the
open neck of the bag.

Now, the sun shines with different degrees of heating power at different
parts of the world. Where its effect is greatest the air there is
hottest. We will suppose, for the sake of argument, that, at a certain
moment, the air envelope all round the globe is of equal temperature.
Suddenly the sun shines out and heats the air at a point, A, till it is
many degrees warmer than the surrounding air. The heated air expands,
rises, and spreads out above the cold air. But, as a given depth of warm
air has less weight than an equal depth of cold air, the cold air at
once begins to rush towards B and squeeze the rest of the warm air out.
We may therefore picture the atmosphere as made up of a number of
colder currents passing along the surface of the earth to replace warm
currents rising and spreading over the upper surface of the cold air. A
similar circulation takes place in a vessel of heated water (see p. 17).


LAND AND SEA BREEZES.

A breeze which blows from the sea on to the land during the day often
reverses its direction during the evening. Why is this? The earth grows
hot or cold more rapidly than the sea. When the sun shines hotly, the
land warms quickly and heats the air over it, which becomes light, and
is displaced by the cooler air over the sea. When the sun sets, the
earth and the air over it lose their warmth quickly, while the sea
remains at practically the same temperature as before. So the balance is
changed, the heavier air now lying over the land. It therefore flows
seawards, and drives out the warmer air there.


LIGHT AIR AND MOISTURE.

Light, warm air absorbs moisture. As it cools, the moisture in it
condenses. Breathe on a plate, and you notice that a watery film forms
on it at once. The cold surface condenses the water suspended in the
warm breath. If you wish to dry a damp room you heat it. Moisture then
passes from the walls and objects in the room to the atmosphere.


THE BAROMETER.

This property of air is responsible for the changes in weather. Light,
moisture-laden air meets cold, dry air, and the sudden cooling forces it
to release its moisture, which falls as rain, or floats about as clouds.
If only we are able to detect the presence of warm air-strata above us,
we ought to be in a position to foretell the weather.

We can judge of the specific gravity of the air in our neighbourhood by
means of the barometer, which means "weight-measurer." The normal
air-pressure at sea-level on our bodies or any other objects is about 15
lbs. to the square inch--that is to say, if you could imprison and weigh
a column of air one inch square in section and of the height of the
world's atmospheric envelope, the scale would register 15 lbs. Many
years ago (1643) Torricelli, a pupil of Galileo, first calculated the
pressure by a very simple experiment. He took a long glass tube sealed
at one end, filled it with mercury, and, closing the open end with the
thumb, inverted the tube and plunged the open end below the surface of a
tank of mercury. On removing his thumb he found that the mercury sank in
the tube till the surface of the mercury in the tube was about 30 inches
in a vertical direction above the surface of the mercury in the tank.
Now, as the upper end was sealed, there must be a vacuum _above_ the
mercury. What supported the column? The atmosphere. So it was evident
that the downward pressure of the mercury exactly counterbalanced the
upward pressure of the air. As a mercury column 30 inches high and 1
inch square weighs 15 lbs., the air-pressure on a square inch obviously
is the same.

[Illustration: FIG. 152.--A Fortin barometer.]


FORTIN'S COLUMN BAROMETER

is a simple Torricellian tube, T, with the lower end submerged in a
little glass tank of mercury (Fig. 152). The bottom of this tank is made
of washleather. To obtain a "reading" the screw S, pressing on the
washleather, is adjusted until the mercury in the tank rises to the tip
of the little ivory point P. The reading is the figure of the scale on
the face of the case opposite which the surface of the column stands.

[Illustration: FIG. 153.]


THE WHEEL BAROMETER

also employs the mercury column (Fig. 153). The lower end of the tube is
turned up and expanded to form a tank, C. The pointer P, which travels
round a graduated dial, is mounted on a spindle carrying a pulley, over
which passes a string with a weight at each end. The heavier of the
weights rests on the top of the mercury. When the atmospheric pressure
falls, the mercury in C rises, lifting this weight, and the pointer
moves. This form of barometer is not so delicate or reliable as
Fortin's, or as the siphon barometer, which has a tube of the same shape
as the wheel instrument, but of the same diameter from end to end
except for a contraction at the bend. The reading of a siphon is the
distance between the two surfaces of the mercury.


A VERY SIMPLE BAROMETER

is made by knocking off the neck of a small bottle, filling the body
with water, and hanging it up by a string in the position shown (Fig.
154). When the atmospheric pressure falls, the water at the orifice
bulges outwards; when it rises, the water retreats till its surface is
slightly concave.

[Illustration: FIG. 154.]


THE ANEROID BAROMETER.

On account of their size and weight, and the comparative difficulty of
transporting them without derangement of the mercury column, column
barometers are not so generally used as the aneroid variety. Aneroid
means "without moisture," and in this particular connection signifies
that no liquid is used in the construction of the barometer.

Fig. 155 shows an aneroid in detail. The most noticeable feature is the
vacuum chamber, V C, a circular box which has a top and bottom of
corrugated but thin and elastic metal. Sections of the box are shown in
Figs. 156, 157. It is attached at the bottom to the base board of the
instrument by a screw (Fig. 156). From the top rises a pin, P, with a
transverse hole through it to accommodate the pin K E, which has a
triangular section, and stands on one edge.

[Illustration: FIG. 155.--An aneroid barometer.]

Returning to Fig. 155, we see that P projects through S, a powerful
spring of sheet-steel. To this is attached a long arm, C, the free end
of which moves a link rotating, through the pin E, a spindle mounted in
a frame, D. The spindle moves arm F. This pulls on a very minute chain
wound round the pointer spindle B, in opposition to a hairspring, H S. B
is mounted on arm H, which is quite independent of the rest of the
aneroid.

[Illustration: FIG. 156. FIG. 157. The vacuum chamber of an aneroid
barometer extended and compressed.]

The vacuum chamber is exhausted during manufacture and sealed. It would
naturally assume the shape of Fig. 157, but the spring S, acting against
the atmospheric pressure, pulls it out. As the pressure varies, so does
the spring rise or sink; and the slightest movement is transmitted
through the multiplying arms C, E, F, to the pointer.

A good aneroid is so delicate that it will register the difference in
pressure caused by raising it from the floor to the table, where it has
a couple of feet less of air-column resting upon it. An aneroid is
therefore a valuable help to mountaineers for determining their altitude
above sea-level.


BAROMETERS AND WEATHER.

We may now return to the consideration of forecasting the weather by
movements of the barometer. The first thing to keep in mind is, that the
instrument is essentially a _weight_ recorder. How is weather connected
with atmospheric weight?

In England the warm south-west wind generally brings wet weather, the
north and east winds fine weather; the reason for this being that the
first reaches us after passing over the Atlantic and picking up a
quantity of moisture, while the second and third have come overland and
deposited their moisture before reaching us.

A sinking of the barometer heralds the approach of heated air--that is,
moist air--which on meeting colder air sheds its moisture. So when the
mercury falls we expect rain. On the other hand, when the "glass" rises,
we know that colder air is coming, and as colder air comes from a dry
quarter we anticipate fine weather. It does not follow that the same
conditions are found in all parts of the world. In regions which have
the ocean to the east or the north, the winds blowing thence would be
the rainy winds, while south-westerly winds might bring hot and dry
weather.


THE DIVING-BELL.

Water is nearly 773 times as heavy as air. If we submerge a barometer a
very little way below the surface of a water tank, we shall at once
observe a rise of the mercury column. At a depth of 34 feet the pressure
on any submerged object is 15 lbs. to the square inch, in addition to
the atmospheric pressure of 15 lbs. per square inch--that is, there
would be a 30-lb. _absolute_ pressure. As a rule, when speaking of
hydraulic pressures, we start with the normal atmospheric pressure as
zero, and we will here observe the practice.

[Illustration: FIG. 158.--A diving bell.]

The diving-bell is used to enable people to work under water without
having recourse to the diving-dress. A sketch of an ordinary
diving-bell is given in Fig. 158. It may be described as a square iron
box without a bottom. At the top are links by which it is attached to a
lowering chain, and windows, protected by grids; also a nozzle for the
air-tube.

[Illustration: FIG. 159.]

A simple model bell (Fig. 159) is easily made out of a glass tumbler
which has had a tap fitted in a hole drilled through the bottom. We turn
off the tap and plunge the glass into a vessel of water. The water rises
a certain way up the interior, until the air within has been compressed
to a pressure equal to that of the water at the level of the surface
inside. The further the tumbler is lowered, the higher does the water
rise inside it.

Evidently men could not work in a diving-bell which is invaded thus by
water. It is imperative to keep the water at bay. This we can do by
attaching a tube to the tap (Fig. 160) and blowing into the tumbler till
the air-pressure exceeds that of the water, which is shown by bubbles
rising to the surface. The diving-bell therefore has attached to it a
hose through which air is forced by pumps from the atmosphere above, at
a pressure sufficient to keep the water out of the bell. This pumping of
air also maintains a fresh supply of oxygen for the workers.

[Illustration: FIG. 160.]

Inside the bell is tackle for grappling any object that has to be moved,
such as a heavy stone block. The diving-bell is used mostly for laying
submarine masonry. "The bell, slung either from a crane on the masonry
already built above sea-level, or from a specially fitted barge, comes
into action. The block is lowered by its own crane on to the bottom. The
bell descends upon it, and the crew seize it with tackle suspended
inside the bell. Instructions are sent up as to the direction in which
the bell should be moved with its burden, and as soon as the exact spot
has been reached the signal for lowering is given, and the stone settles
on to the cement laid ready for it."[34]

For many purposes it is necessary that the worker should have more
freedom of action than is possible when he is cooped up inside an iron
box. Hence the invention of the


DIVING-DRESS,

which consists of two main parts, the helmet and the dress proper. The
helmet (Fig. 161) is made of copper. A breastplate, B, shaped to fit the
shoulders, has at the neck a segmental screw bayonet-joint. The
headpiece is fitted with a corresponding screw, which can be attached or
removed by one-eighth of a turn. The neck edge of the dress, which is
made in one piece, legs, arms, body and all, is attached to the
breastplate by means of the plate P^1, screwed down tightly on it by
the wing-nuts N N, the bolts of which pass through the breastplate. Air
enters the helmet through a valve situated at the back, and is led
through tubes along the inside to the front. This valve closes
automatically if any accident cuts off the air supply, and encloses
sufficient air in the dress to allow the diver to regain the surface.
The outlet valve O V can be adjusted by the diver to maintain any
pressure. At the sides of the headpiece are two hooks, H, over which
pass the cords connecting the heavy lead weights of 40 lbs. each hanging
on the diver's breast and back. These weights are also attached to the
knobs K K. A pair of boots, having 17 lbs. of lead each in the soles,
complete the dress. Three glazed windows are placed in the headpiece,
that in the front, R W, being removable, so that the diver may gain free
access to the air when he is above water without being obliged to take
off the helmet.

[Illustration: FIG. 161.--A diver's helmet.]

By means of telephone wires built into the life-line (which passes
under the diver's arms and is used for lowering and hoisting) easy
communication is established between the diver and his attendants above.
The transmitter of the telephone is placed inside the helmet between the
front and a side window, the receiver and the button of an electric bell
in the crown. This last he can press by raising his head. The life-line
sometimes also includes the wires for an electric lamp (Fig. 162) used
by the diver at depths to which daylight cannot penetrate.

The pressure on a diver's body increases in the ratio of 4-1/3 lbs. per
square inch for every 10 feet that he descends. The ordinary working
limit is about 150 feet, though "old hands" are able to stand greater
pressures. The record is held by one James Hooper, who, when removing
the cargo of the _Cape Horn_ sunk off the South American coast, made
seven descents of 201 feet, one of which lasted for forty-two minutes.

[Illustration: FIG. 162.--Diver's electric lamp.]

A sketch is given (Fig. 163) of divers working below water with
pneumatic tools, fed from above with high-pressure air. Owing to his
buoyancy a diver has little depressing or pushing power, and he cannot
bore a hole in a post with an auger unless he is able to rest his back
against some firm object, or is roped to the post. Pneumatic chipping
tools merely require holding to their work, their weight offering
sufficient resistance to the very rapid blows which they make.

[Illustration: FIG. 163.--Divers at work below water with pneumatic
tools.]


AIR-PUMPS.

[Illustration: FIG. 164.]

[Illustration: FIG. 165.]

Mention having been made of the air-pump, we append diagrams (Figs. 164,
165) of the simplest form of air-pump, the cycle tyre inflator. The
piston is composed of two circular plates of smaller diameter than the
barrel, holding between them a cup leather. During the upstroke the cup
collapses inwards and allows air to pass by it. On the downstroke (Fig.
165) the edges of the cup expand against the barrel, preventing the
passage of air round the piston. A double-action air-pump requires a
long, well-fitting piston with a cup on each side of it, and the
addition of extra valves to the barrel, as the cups under these
circumstances cannot act as valves.


PNEUMATIC TYRES.

[Illustration: FIG. 166.]

[Illustration: FIG. 167.]

The action of the pneumatic tyre in reducing vibration and increasing
the speed of a vehicle is explained by Figs. 166, 167. When the tyre
encounters an obstacle, such as a large stone, it laps over it (Fig.
166), and while supporting the weight on the wheel, reduces the
deflection of the direction of movement. When an iron-tyred wheel meets
a similar obstacle it has to rise right over it, often jumping a
considerable distance into the air. The resultant motions of the wheel
are indicated in each case by an arrow. Every change of direction means
a loss of forward velocity, the loss increasing with the violence and
extent of the change. The pneumatic tyre also scores because, on account
of its elasticity, it gives a "kick off" against the obstacle, which
compensates for the resistance during compression.

[Illustration: FIG. 168.--Section of the mechanism of an air-gun.]


THE AIR-GUN.

This may be described as a valveless air-pump. Fig. 168 is a section of
a "Gem" air-gun, with the mechanism set ready for firing. In the stock
of the gun is the _cylinder_, in which an accurately fitting and hollow
_piston_ moves. A powerful helical spring, turned out of a solid bar of
steel, is compressed between the inside end of the piston and the upper
end of the butt. To set the gun, the _catch_ is pressed down so that its
hooked end disengages from the stock, and the barrel is bent downwards
on pivot P. This slides the lower end of the _compressing lever_ towards
the butt, and a projection on the guide B, working in a groove, takes
the piston with it. When the spring has been fully compressed, the
triangular tip of the rocking cam R engages with a groove in the
piston's head, and prevents recoil when the barrel is returned to its
original position. On pulling the trigger, the piston is released and
flies up the cylinder with great force, and the air in the cylinder is
compressed and driven through the bore of the barrel, blocked by the
leaden slug, to which the whole energy of the expanding spring is
transmitted through the elastic medium of the air.

There are several other good types of air-gun, all of which employ the
principles described above.


THE SELF-CLOSING DOOR-STOP

is another interesting pneumatic device. It consists of a cylinder with
an air-tight piston, and a piston rod working through a cover at one
end. The other end of the cylinder is pivoted to the door frame. When
the door is opened the piston compresses a spring in the cylinder, and
air is admitted past a cup leather on the piston to the upper part of
the cylinder. This air is confined by the cup leather when the door is
released, and escapes slowly through a leak, allowing the spring to
regain its shape slowly, and by the agency of the piston rod to close
the door.


THE ACTION OF WIND ON OBLIQUE SURFACES.

Why does a kite rise? Why does a boat sail across the wind? We can
supply an answer almost instinctively in both cases, "Because the wind
pushes the kite or sail aside." It will, however, be worth while to look
for a more scientific answer. The kite cannot travel in the direction of
the wind because it is confined by a string. But the face is so attached
to the string that it inclines at an angle to the direction of the wind.
Now, when a force meets an inclined surface which it cannot carry along
with it, but which is free to travel in another direction, the force may
be regarded as resolving itself into _two_ forces, coming from each side
of the original line. These are called the _component_ forces.

[Illustration: FIG. 169.]

To explain this we give a simple sketch of a kite in the act of flying
(Fig. 169). The wind is blowing in the direction of the solid arrow A.
The oblique surface of the kite resolves its force into the two
components indicated by the dotted arrows B and C. Of these C only has
lifting power to overcome the force of gravity. The kite assumes a
position in which force C and gravity counterbalance one another.

[Illustration: FIG. 170.]

A boat sailing across the wind is acted on in a similar manner (Fig.
170). The wind strikes the sail obliquely, and would thrust it to
leeward were it not for the opposition of the water. The force A is
resolved into forces B and C, of which C propels the boat on the line of
its axis. The boat can be made to sail even "up" the wind, her head
being brought round until a point is reached at which the force B on the
boat, masts, etc., overcomes the force C. The capability of a boat for
sailing up wind depends on her "lines" and the amount of surface she
offers to the wind.


THE BALLOON

is a pear-shaped bag--usually made of silk--filled with some gas lighter
than air. The tendency of a heavier medium to displace a lighter drives
the gas upwards, and with it the bag and the wicker-work car attached to
a network encasing the bag. The tapering neck at the lower end is open,
to permit the free escape of gas as the atmospheric pressure outside
diminishes with increasing elevation. At the top of the bag is a wooden
valve opening inwards, which can be drawn down by a rope passing up to
it through the neck whenever the aeronaut wishes to let gas escape for a
descent. He is able to cause a very rapid escape by pulling another cord
depending from a "ripping piece" near the top of the bag. In case of
emergency this is torn away bodily, leaving a large hole. The ballast
(usually sand) carried enables him to maintain a state of equilibrium
between the upward pull of the gas and the downward pull of gravity. To
sink he lets out gas, to rise he throws out ballast; and this process
can be repeated until the ballast is exhausted. The greatest height ever
attained by aeronauts is the 7-1/4 miles, or 37,000 feet, of Messrs.
Glaisher and Coxwell on September 5, 1862. The ascent nearly cost them
their lives, for at an elevation of about 30,000 feet they were partly
paralyzed by the rarefaction of the air, and had not Mr. Coxwell been
able to pull the valve rope with his teeth and cause a descent, both
would have died from want of air.

[Illustration: FIG. 171.]

The _flying-machine_, which scientific engineers have so long been
trying to produce, will probably be quite independent of balloons, and
will depend for its ascensive powers on the action of air on oblique
surfaces. Sir Hiram Maxim's experimental air-ship embodied the
principles shown by Fig. 171. On a deck was mounted an engine, E,
extremely powerful for its weight. This drove large propellers, S S.
Large aeroplanes, of canvas stretched over light frameworks, were set up
overhead, the forward end somewhat higher than the rear. The machine was
run on rails so arranged as to prevent it rising. Unfortunately an
accident happened at the first trial and destroyed the machine.

In actual flight it would be necessary to have a vertical rudder for
altering the horizontal direction, and a horizontal "tail" for steering
up or down. The principle of an aeroplane is that of the kite, with this
difference, that, instead of moving air striking a captive body, a
moving body is propelled against more or less stationary air. The
resolution of forces is shown by the arrows as before.

Up to the present time no practical flying-machine has appeared. But
experimenters are hard at work examining the conditions which must be
fulfilled to enable man to claim the "dominion of the air."

[34] The "Romance of Modern Mechanism," p. 243




Chapter XVIII.

HYDRAULIC MACHINERY.

     The siphon--The bucket pump--The force-pump--The most marvellous
     pump--The blood channels--The course of the blood--The hydraulic
     press--Household water-supply fittings--The ball-cock--The
     water-meter--Water-supply systems--The household filter--Gas
     traps--Water engines--The cream separator--The "hydro."


In the last chapter we saw that the pressure of the atmosphere is 15
lbs. to the square inch. Suppose that to a very long tube having a
sectional area of one square inch we fit an air-tight piston (Fig. 172),
and place the lower end of the tube in a vessel of water. On raising the
piston a vacuum would be created in the tube, did not the pressure of
the atmosphere force water up into the tube behind the piston. The water
would continue to rise until it reached a point 34 feet perpendicularly
above the level of the water in the vessel. The column would then weigh
15 lbs., and exactly counterbalance the atmospheric pressure; so that a
further raising of the piston would not raise the water any farther. At
sea-level, therefore, the _lifting_ power of a pump by suction is
limited to 34 feet. On the top of a lofty mountain, where the
air-pressure is less, the height of the column would be diminished--in
fact, be proportional to the pressure.

[Illustration: FIG. 172.]

[Illustration: FIG. 173.]


THE SIPHON

is an interesting application of the principle of suction. By its own
weight water may be made to lift water through a height not exceeding 34
feet. This is explained by Fig. 173. The siphon pipe, A B C D, is in the
first instance filled by suction. The weight of the water between A and
B counter-balances that between B and C. But the column C D hangs, as it
were, to the heels of B C, and draws it down. Or, to put it otherwise,
the column B D, being heavier than the column B A, draws it over the
topmost point of the siphon. Any parting between the columns, provided
that B A does not exceed 34 feet, is impossible, as the pressure of the
atmosphere on the mouth of B A is sufficient to prevent the formation of
a vacuum.


THE BUCKET PUMP.

We may now pass to the commonest form of pump used in houses, stables,
gardens, etc. (Fig. 174). The piston has a large hole through it, over
the top of which a valve is hinged. At the bottom of the barrel is a
second valve, also opening upwards, seated on the top of the supply
pipe. In sketch (_a_) the first upstroke is in progress. A vacuum forms
under the piston, or plunger, and water rises up the barrel to fill it.
The next diagram (_b_) shows the first downstroke. The plunger valve
now opens and allows water to rise above the piston, while the lower
closes under the pressure of the water above and the pull of that below.
During the second upstroke (_c_) the water above the piston is raised
until it overflows through the spout, while a fresh supply is being
sucked in below.

[Illustration: FIG. 174.]


THE FORCE-PUMP.

[Illustration: FIG. 175. Force-pump; suction stroke.]

[Illustration: FIG. 176. Force-pump; delivery stroke.]

For driving water to levels above that of the pump a somewhat different
arrangement is required. One type of force-pump is shown in Figs. 175,
176. The piston now is solid, and the upper valve is situated in the
delivery pipe. During an upstroke this closes, and the other opens; the
reverse happening during a downstroke. An air-chamber is generally
fitted to the delivery pipe when water is to be lifted to great heights
or under high pressure. At each delivery stroke the air in the chamber
is compressed, absorbing some of the shock given to the water in the
pipe by the water coming from the pump; and its expansion during the
next suction stroke forces the water gradually up the pipe. The
air-chamber is a very prominent feature of the fire-engine.

A _double-action_ force-pump is seen in Fig. 177, making an upward
stroke. Both sides of the piston are here utilized, and the piston rod
works through a water-tight stuffing-box. The action of the pump will be
easily understood from the diagram.

[Illustration: FIG. 177.]


THE MOST MARVELLOUS PUMP

known is the _heart_. We give in Fig. 178 a diagrammatic sketch of the
system of blood circulation in the human body, showing the heart, the
arteries, and the veins, big and little. The body is supposed to be
facing the reader, so that the left lung, etc., is to his right.

[Illustration: FIG. 178.--A diagrammatic representation of the
circulatory system of the blood.]

The heart, which forces the blood through the body, is a large muscle
(of about the size of the clenched fist) with four cavities. These are
respectively known as the right and left _auricles_, and the right and
left _ventricles_. They are arranged in two pairs, the auricle
uppermost, separated by a fleshy partition. Between each auricle and its
ventricle is a valve, which consists of strong membranous flaps, with
loose edges turned downwards. The left-side valve is the _mitral_ valve,
that between the right auricle and ventricle the _tricuspid_ valve. The
edges of the valves fall together when the heart contracts, and prevent
the passage of blood. Each ventricle has a second valve through which it
ejects the blood. (That of the right ventricle has been shown double for
the sake of convenience.)

The action of the heart is this:--The auricles and ventricles expand;
blood rushes into the auricles from the channels supplying them, and
distends them and the ventricles; the auricles contract and fill the
ventricles below quite full (there are no valves above the auricles, but
the force of contraction is not sufficient to return the blood to the
veins); the ventricles contract; the mitral and tricuspid valves close;
the valves leading to the arteries open; blood is forced out of the
ventricles.


THE BLOOD CHANNELS

are of two kinds--(1) The _arteries_, which lead the blood into the
circulatory system; (2) the _veins_, which lead the blood back to the
heart. The arteries divide up into branches, and these again divide into
smaller and smaller arteries. The smallest, termed _capillaries_ (Latin,
_capillus_, a hair), are minute tubes having an average diameter of
1/3000th of an inch. These permeate every part of the body. The
capillary arteries lead into the smallest veins, which unite to form
larger and larger veins, until what we may call the main streams are
reached. Through these the blood flows to the heart.

There are three main points of difference between arteries and veins. In
the first place, the larger arteries have thick elastic walls, and
maintain their shape even when empty. This elasticity performs the
function of the air-chamber of the force-pump. When the ventricles
contract, driving blood into the arteries, the walls of the latter
expand, and their contraction pushes the blood steadily forward without
shock. The capillaries have very thin walls, so that fluids pass through
them to and from the body, feeding it and taking out waste matter. The
veins are all thin-walled, and collapse when empty. Secondly, most veins
are furnished with valves, which prevent blood flowing the wrong way.
These are similar in principle to those of the heart. Arteries have no
valves. Thirdly, arteries are generally deeply set, while many of the
veins run near the surface of the body. Those on the front of the arm
are specially visible. Place your thumb on them and run it along towards
the wrist, and you will notice that the veins distend owing to the
closing of the valves just mentioned.

Arterial blood is _red_, and comes out from a cut in gulps, on account
of the contraction of the elastic walls. If you cut a vein, _blue_ blood
issues in a steady stream. The change of colour is caused by the loss of
oxygen during the passage of the blood through the capillaries, and the
absorption of carbon dioxide from the tissues.

The _lungs_ are two of the great purifiers of the blood. As it
circulates through them, it gives up the carbon dioxide which it has
absorbed, and receives pure oxygen in exchange. If the air of a room is
"foul," the blood does not get the proper amount of oxygen. For this
reason it is advisable for us to keep the windows of our rooms open as
much as possible both day and night. Fatigue is caused by the
accumulation of carbon dioxide and other impurities in the blood. When
we run, the heart pumps blood through the lungs faster than they can
purify it, and eventually our muscles become poisoned to such an extent
that we have to stop from sheer exhaustion.


THE COURSE OF THE BLOOD.

It takes rather less than a minute for a drop of blood to circulate from
the heart through the whole system and back to the heart.

We may briefly summarize the course of the circulation of the blood
thus:--It is expelled from the left ventricle into the _aorta_ and the
main arteries, whence it passes into the smaller arteries, and thence
into the capillaries of the brain, stomach, kidneys, etc. It here
imparts oxygen to the body, and takes in impurities. It then enters the
veins, and through them flows back to the right auricle; is driven into
the right ventricle; is expelled into the _pulmonary_ (lung)
_arteries_; enters the lungs, and is purified. It returns to the left
auricle through the _pulmonary veins_; enters the left auricle, passes
to left ventricle, and so on.

A healthy heart beats from 120 times per minute in a one-year-old infant
to 60 per minute in a very aged person. The normal rate for a
middle-aged adult is from 80 to 70 beats.

Heart disease signifies the failure of the heart valves to close
properly. Blood passes back when the heart contracts, and the
circulation is much enfeebled. By listening through a stethoscope the
doctor is able to tell whether the valves are in good order. A hissing
sound during the beat indicates a leakage past the valves; a thump, or
"clack," that they shut completely.


THE HYDRAULIC PRESS.

It is a characteristic of fluids and gases that if pressure be brought
to bear on any part of a mass of either class of bodies it is
transmitted equally and undiminished in all directions, and acts with
the same force on all equal surfaces, at right angles to those surfaces.
The great natural philosopher Pascal first formulated this remarkable
fact, of which a simple illustration is given in Fig. 179. Two
cylinders, A and B, having a bore of one and two inches respectively,
are connected by a pipe. Water is poured in, and pistons fitting the
cylinders accurately and of equal weight are inserted. On piston B is
placed a load of 10 lbs. To prevent A rising above the level of B, it
must be loaded proportionately. The area of piston A is four times that
of B, so that if we lay on it a 40-lb. weight, neither piston will move.
The walls of the cylinders and connecting pipe are also pressed outwards
in the ratio of 10 lbs. for every part of their interior surface which
has an area equal to that of piston B.

[Illustration: FIG. 179.]

[Illustration: FIG. 180.--The cylinder and ram of a hydraulic press.]

The hydraulic press is an application of this law. Cylinder B is
represented by a force pump of small bore, capable of delivering water
at very high pressures (up to 10 tons per square inch). In the place of
A we have a stout cylinder with a solid plunger, P (Fig. 180), carrying
the _table_ on which the object to be pressed is placed. Bramah, the
inventor of the hydraulic press, experienced great difficulty in
preventing the escape of water between the top of the cylinder and the
plunger. If a "gland" packing of the type found in steam-cylinders were
used, it failed to hold back the water unless it were screwed down so
tightly as to jam the plunger. He tried all kinds of expedients without
success; and his invention, excellent though it was in principle, seemed
doomed to failure, when his foreman, Henry Maudslay,[35] solved the
problem in a simple but most masterly manner. He had a recess turned in
the neck of the cylinder at the point formerly occupied by the
stuffing-box, and into this a leather collar of U-section (marked solid
black in Fig. 180) was placed with its open side downwards. When water
reached it, it forced the edges apart, one against the plunger, the
other against the walls of the recess, with a degree of tightness
proportionate to the pressure. On water being released from the cylinder
the collar collapsed, allowing the plunger to sink without friction.

The principle of the hydraulic press is employed in lifts; in machines
for bending, drilling, and riveting steel plates, or forcing wheels on
or off their axles; for advancing the "boring shield" of a tunnel; and
for other purposes too numerous to mention.


HOUSEHOLD WATER-SUPPLY FITTINGS.

Among these, the most used is the tap, or cock. When a house is served
by the town or district water supply, the fitting of proper taps on all
pipes connected with the supply is stipulated for by the water-works
authorities. The old-fashioned "plug" tap is unsuitable for controlling
high-pressure water on account of the suddenness with which it checks
the flow. Lest the reader should have doubts as to the nature of a plug
tap, we may add that it has a tapering cone of metal working in a
tapering socket. On the cone being turned till a hole through it is
brought into line with the channel of the tap, water passes. A quarter
turn closes the tap.

[Illustration: FIG. 181.--A screw-down water cock.]

Its place has been taken by the screw-down cock. A very common and
effective pattern is shown in Fig. 181. The valve V, with a facing of
rubber, leather, or some other sufficiently elastic substance, is
attached to a pin, C, which projects upwards into the spindle A of the
tap. This spindle has a screw thread on it engaging with a collar, B.
When the spindle is turned it rises or falls, allowing the valve to
leave its seating, V S, or forcing it down on to it. A packing P in the
neck of B prevents the passage of water round the spindle. To open or
close the tap completely is a matter of several turns, which cannot be
made fast enough to produce a "water-hammer" in the pipes by suddenly
arresting the flow. The reader will easily understand that if water
flowing at the rate of several miles an hour is abruptly checked, the
shock to the pipes carrying it must be very severe.


THE BALL-COCK

is used to feed a cistern automatically with water, and prevent the
water rising too far in the cistern (Fig. 182). Water enters the cistern
through a valve, which is opened and closed by a plug faced with rubber.
The lower extremity of the plug is flattened, and has a rectangular hole
cut in it. Through this passes a lever, L, attached at one end to a
hollow copper sphere, and pivoted at the other on the valve casing. This
casing is not quite circular in section, for two slots are cast in the
circumference to allow water to pass round the plug freely when the
valve is open. The buoyancy of the copper sphere is sufficient to force
the plug's face up towards its seating as the valve rises, and to cut
off the supply entirely when a certain level has been attained. If water
is drawn off, the sphere sinks, the valve opens, and the loss is made
good.

[Illustration: FIG. 182.--An automatic ball-valve.]


THE WATER-METER.

[Illustration: FIG. 183.]

Some consumers pay a sum quarterly for the privilege of a water supply,
and the water company allows them to use as much as they require.
Others, however, prefer to pay a fixed amount for every thousand gallons
used. In such cases, a water-meter is required to record the
consumption. We append a sectional diagram of Kennedy's patent
water-meter (Fig. 183), very widely used. At the bottom is the measuring
cylinder, fitted with a piston, (6), which is made to move perfectly
water-tight and free from friction by means of a cylindrical ring of
india-rubber, rolling between the body of the piston and the internal
surface of the cylinder. The piston rod (25), after passing through a
stuffing-box in the cylinder cover, is attached to a rack, (15), which
gears with a cog, (13), fixed on a shaft. As the piston moves up and
down, this cog is turned first in one direction, then in the other. To
this shaft is connected the index mechanism (to the right). The cock-key
(24) is so constructed that it can put either end of the measuring
cylinder in communication with the supply or delivery pipes, if given a
quarter turn (see Fig. 184). The weighted lever (14) moves loosely on
the pinion shaft through part of a circle. From the pinion project two
arms, one on each side of the lever. When the lever has been lifted by
one of these past the vertical position, it falls by its own weight on
to a buffer-box rest, (18). In doing so, it strikes a projection on the
duplex lever (19), which is joined to the cock-key, and gives the latter
a quarter turn.

In order to follow the working of the meter, we must keep an eye on
Figs. 183 and 184 simultaneously. Water is entering from A, the supply
pipe. It flows through the cock downwards through channel D into the
lower half of the cylinder. The piston rises, driving out the water
above it through C to the delivery pipe B. Just as the piston completes
its stroke the weight, raised by the rack and pinion, topples over, and
strikes the key-arm, which it sends down till stopped by the
buffer-box. The tap is then at right angles to the position shown in
Fig. 184, and water is directed from A down C into the top of the
cylinder, forcing the piston down, while the water admitted below during
the last stroke is forced up the passage D, and out by the outlet B.
Before the piston has arrived at the bottom of the cylinder, the lifter
will have lifted the weighted lever from the buffer-box, and raised it
to a vertical position; from there it will have fallen on the right-hand
key-arm, and have brought the cock-key to its former position, ready to
begin another upward stroke.

[Illustration: FIG. 184.]

The _index mechanism_ makes allowance for the fact that the bevel-wheel
on the pinion shaft has its direction reversed at the beginning of every
stroke of the piston. This bevel engages with two others mounted loosely
on the little shaft, on which is turned a screw thread to revolve the
index counter wheels. Each of these latter bevels actuates the shaft
through a ratchet; but while one turns the shaft when rotating in a
clockwise direction only, the other engages it when making an
anti-clockwise revolution. The result is that the shaft is always turned
in the same direction.


WATER-SUPPLY SYSTEMS.

The water for a town or a district supply is got either from wells or
from a river. In the former case it may be assumed to be free from
impurities. In the latter, there is need for removing all the
objectionable and dangerous matter which river water always contains in
a greater or less degree. This purification is accomplished by first
leading the water into large _settling tanks_, where the suspended
matter sinks to the bottom. The water is then drawn off into
_filtration beds_, made in the following manner. The bottom is covered
with a thick layer of concrete. On this are laid parallel rows of
bricks, the rows a small distance apart. Then come a layer of bricks or
tiles placed close together; a layer of coarse gravel; a layer of finer
gravel; and a thick layer of sand at the top. The sand arrests any solid
matter in the water as it percolates to the gravel and drains below.
Even the microbes,[36] of microscopic size, are arrested as soon as the
film of mud has formed on the top of the sand. Until this film is formed
the filter is not in its most efficient condition. Every now and then
the bed is drained, the surface mud and sand carefully drained off, and
fresh sand put in their place. A good filter bed should not pass more
than from two to three gallons per hour for every square foot of
surface, and it must therefore have a large area.

It is sometimes necessary to send the water through a succession of
beds, arranged in terraces, before it is sufficiently pure for drinking
purposes.


THE HOUSEHOLD FILTER.

When there is any doubt as to the wholesomeness of the water supply, a
small filter is often used. The microbe-stopper is usually either
charcoal, sand, asbestos, or baked clay of some kind. In Fig. 185 we
give a section of a Maignen filter. R is the reservoir for the filtered
water; A the filter case proper; D a conical perforated frame; B a
jacket of asbestos cloth secured top and bottom by asbestos cords to D;
C powdered carbon, between which and the asbestos is a layer of special
chemical filtering medium. A perforated cap, E, covers in the carbon and
prevents it being disturbed when water is poured in. The carbon arrests
the coarser forms of matter; the asbestos the finer. The asbestos jacket
is easily removed and cleansed by heating over a fire.

[Illustration: FIG. 185.]

The most useful form of household filter is one which can be attached to
a tap connected with the main. Such a filter is usually made of
porcelain or biscuit china. The Berkefeld filter has an outer case of
iron, and an interior hollow "candle" of porcelain from which a tube
passes through the lid of the filter to a storage tank for the filtered
water. The water from the main enters the outer case, and percolates
through the porcelain walls to the internal cavity and thence flows away
through the delivery pipe.

Whatever be the type of filter used it must be cleansed at proper
intervals. A foul filter is very dangerous to those who drink the water
from it. It has been proved by tests that, so far from purifying the
water, an inefficient and contaminated filter passes out water much more
highly charged with microbes than it was before it entered. We must not
therefore think that, because water has been filtered, it is necessarily
safe. The reverse is only too often the case.


GAS TRAPS.

Dangerous microbes can be breathed as well as drunk into the human
system. Every communication between house and drains should be most
carefully "trapped." The principle of a gas trap between, say, a kitchen
sink and the drain to carry off the water is given in Fig. 186. Enough
water always remains in the bend to rise above the level of the elbow,
effectually keeping back any gas that there may be in the pipe beyond
the bend.

[Illustration: FIG. 186.--A trap for foul air.]


WATER-ENGINES.

Before the invention of the steam-engine human industries were largely
dependent on the motive power of the wind and running water. But when
the infant nursed by Watt and Stephenson had grown into a giant, both of
these natural agents were deposed from the important position they once
held. Windmills in a state of decay crown many of our hilltops, and the
water-wheel which formerly brought wealth to the miller now rots in its
mountings at the end of the dam. Except for pumping and moving boats and
ships, wind-power finds its occupation gone. It is too uncertain in
quantity and quality to find a place in modern economics. Water-power,
on the other hand, has received a fresh lease of life through the
invention of machinery so scientifically designed as to use much more of
the water's energy than was possible with the old-fashioned wheel.

[Illustration: FIG. 187.--A Pelton wheel which develops 5,000
horse-power. Observe the shape of the double buckets.]

The _turbine_, of which we have already spoken in our third chapter, is
now the favourite hydraulic engine. Some water-turbines work on much the
same principle as the Parsons steam-turbine; others resemble the De
Laval. Among the latter the Pelton wheel takes the first place. By the
courtesy of the manufacturers we are able to give some interesting
details and illustrations of this device.

[Illustration: FIG. 188.--Pelton wheel mounted, with nozzle in
position.]

The wheel, which may be of any diameter from six inches to ten feet, has
buckets set at regular intervals round the circumference, sticking
outwards. Each bucket, as will be gathered from our illustration of an
enormous 5,000 h.p. wheel (Fig. 187), is composed of two cups. A nozzle
is so arranged as to direct water on the buckets just as they reach the
lowest point of a revolution (see Fig. 188). The water strikes the
bucket on the partition between the two cups, which turns it right and
left round the inside of the cups. The change of direction transfers the
energy of the water to the wheel.

[Illustration: FIG. 189.--Speed regulator for Pelton wheel.]

The speed of the wheel may be automatically regulated by a deflecting
nozzle (Fig. 189), which has a ball and socket joint to permit of its
being raised or lowered by a centrifugal governor, thus throwing the
stream on or off the buckets. The power of the wheel is consequently
increased or diminished to meet the change of load, and a constant speed
is maintained. When it is necessary to waste as little water as
possible, a concentric tapered needle may be fitted inside the nozzle.
When the nozzle is in its highest position the needle tip is withdrawn;
as the nozzle sinks the needle protrudes, gradually decreasing the
discharge area of the nozzle.

Pelton wheels are designed to run at all speeds and to use water of any
pressure. At Manitou, Colorado, is an installation of three wheels
operated by water which leaves the nozzle at the enormous pressure of
935 lbs. per square inch. It is interesting to note that jets of very
high-pressure water offer astonishing resistance to any attempt to
deflect their course. A three-inch jet of 500-lb. water cannot be cut
through by a blow from a crowbar.

In order to get sufficient pressure for working hydraulic machinery in
mines, factories, etc., water is often led for many miles in flumes, or
artificial channels, along the sides of valleys from the source of
supply to the point at which it is to be used. By the time that point is
reached the difference between the gradients of the flume and of the
valley bottom has produced a difference in height of some hundreds of
feet.

[Illustration: FIG. 190.--The Laxey water-wheel, Isle of Man. In the
top right-hand corner is a Pelton wheel of proportionate size required
to do the same amount of work with the same consumption of water at the
same pressure.]

The full-page illustration on p. 380 affords a striking testimony to
the wonderful progress made in engineering practice during the last
fifty years. The huge water-wheel which forms the bulk of the picture is
that at Laxey, in the Isle of Man. It is 72-1/2 feet in diameter, and is
supposed to develop 150 horse-power, which is transmitted several
hundreds of feet by means of wooden rods supported at regular intervals.
The power thus transmitted operates a system of pumps in a lead mine,
raising 250 gallons of water per minute, to an elevation of 1,200 feet.
The driving water is brought some distance to the wheel in an
underground conduit, and is carried up the masonry tower by pressure,
flowing over the top into the buckets on the circumference of the wheel.

The little cut in the upper corner represents a Pelton wheel drawn on
the same scale, which, given an equal supply of water at the same
pressure, would develop the same power as the Laxey monster. By the side
of the giant the other appears a mere toy.


THE CREAM SEPARATOR.

In 1864 Denmark went to war with Germany, and emerged from the short
struggle shorn of the provinces of Lauenburg, Holstein, and Schleswig.
The loss of the two last, the fairest and most fertile districts of the
kingdom, was indeed grievous. The Danish king now ruled only over a land
consisting largely of moor, marsh, and dunes, apparently worthless for
any purpose. But the Danes, with admirable courage, entered upon a
second struggle, this time with nature. They made roads and railways,
dug irrigation ditches, and planted forest trees; and so gradually
turned large tracts of what had been useless country into valuable
possessions. Agriculture being much depressed, owing to the low price of
corn, they next gave their attention to the improvement of dairy
farming. Labour-saving machinery of all kinds was introduced, none more
important than the device for separating the fatty from the watery
constituents of milk. It would not be too much to say that the separator
is largely responsible for the present prosperity of Denmark.

[Illustration: FIG. 191.--Section of a Cream Separator.]

How does it work? asks the reader. Centrifugal force[37] is the
governing principle. To explain its application we append a sectional
illustration (Fig. 191) of Messrs. Burmeister and Wain's hand-power
separator, which may be taken as generally representative of this class
of machines. Inside a circular casing is a cylindrical bowl, D, mounted
on a shaft which can be revolved 5,000 times a minute by means of the
cog-wheels and the screw thread chased on it near the bottom extremity.
Milk flows from the reservoir R (supported on a stout arm) through tap A
into a little distributer on the top of the separator, and from it drops
into the central tube C of the bowl. Falling to the bottom, it is flung
outwards by centrifugal force, finds an escape upwards through the holes
_a a_, and climbs up the perforated grid _e_, the surface of which is a
series of pyramidical excrescences, and finally reaches the inner
surface of the drum proper. The velocity of rotation is so tremendous
that the heavier portions of the milk--that is, the watery--crowd
towards the point furthest from the centre, and keep the lighter fatty
elements away from contact with the sides of the drum. In the diagram
the water is represented by small circles, the cream by small crosses.

As more milk enters the drum it forces upwards what is already there.
The cap of the drum has an inner jacket, F, which at the bottom _all but
touches_ the side of the drum. The distance between them is the merest
slit; but the cream is deflected up outside F into space E, and escapes
through a hole one-sixteenth of an inch in diameter perforating the
plate G. The cream is flung into space K and trickles out of spout B,
while the water flies into space H and trickles away through spout A.


THE "HYDRO.,"

used in laundries for wringing clothes by centrifugal force, has a solid
outer casing and an inner perforated cylindrical cage, revolved at high
speed by a vertical shaft. The wet clothes are placed in the cage, and
the machine is started. The water escapes through the perforations and
runs down the side of the casing to a drain. After a few minutes the
clothes are dry enough for ironing. So great is the centrifugal force
that they are consolidated against the sides of the cage, and care is
needed in their removal.

[35] Inventor of the lathe slide-rest.

[36] Living germs; some varieties the cause of disease.

[37] That is, centre-fleeing force. Water dropped on a spinning top
rushes towards the circumference and is shot off at right angles to a
line drawn from the point of parting to the centre of the top.




Chapter XIX.

HEATING AND LIGHTING.

     The hot-water supply--The tank system--The cylinder system--How a
     lamp works--Gas and gasworks--Automatic stoking--A gas
     governor--The gas meter--Incandescent gas lighting.


HOT-WATER SUPPLY.

A well-equipped house is nowadays expected to contain efficient
apparatus for supplying plenty of hot water at all hours of the day.
There is little romance about the kitchen boiler and the pipes which the
plumber and his satellites have sometimes to inspect and put right, but
the methods of securing a proper circulation of hot water through the
house are sufficiently important and interesting to be noticed in these
pages.

In houses of moderate size the kitchen range does the heating. The two
systems of storing and distributing the heated water most commonly used
are--(1) The _tank_ system; (2) the _cylinder_ system.


THE TANK SYSTEM

is shown diagrammatically in Fig. 192. The boiler is situated at the
back of the range, and when a "damper" is drawn the fire and hot gases
pass under it to a flue leading to the chimney. The almost boiling water
rises to the top of the boiler and thence finds its way up the _flow
pipe_ into the hot-water tank A, displacing the somewhat colder water
there, which descends through the _return pipe_ to the bottom of the
boiler.

Water is drawn off from the flow pipe. This pipe projects some distance
through the bottom of A, so that the hottest portion of the contents may
be drawn off first. A tank situated in the roof, and fed from the main
by a ball-cock valve, communicates with A through the siphon pipe S. The
bend in this pipe prevents the ascent of hot water, which cannot sink
through water colder than itself. From the top of A an _expansion pipe_
is led up and turned over the cold-water tank to discharge any steam
which may be generated in the boiler.

A hot-water radiator for warming the house may be connected to the flow
and return pipes as shown. Since it opens a "short circuit" for the
circulation, the water in the tank above will not be so well heated
while it is in action. If cocks are fitted to the radiator pipes, the
amount of heat thus deflected can be governed.

[Illustration: FIG. 192.--The "tank" system of hot-water supply.]

A disadvantage of the tank system is that the tank, if placed high
enough to supply all flows, is sometimes so far from the boiler that the
water loses much of its heat in the course of circulation. Also, if for
any reason the cold water fails, tank A may be entirely emptied,
circulation cease, and the water in the boiler and pipes boil away
rapidly.


THE CYLINDER SYSTEM

(Fig. 193) is open to neither of these objections. Instead of a
rectangular tank up aloft, we now have a large copper cylinder situated
in the kitchen near the range. The flow and return pipes are continuous,
and the cold supply enters the bottom of the cylinder through a pipe
with a siphon bend in it. As before, water is drawn off from the flow
pipe, and a radiator may be put in the circuit. Since there is no
draw-off point below the top of the cylinder, even if the cold supply
fails the cylinder will remain full, and the failure will be discovered
long before there is any danger of the water in it boiling away.

[Illustration: FIG. 193.--The "cylinder" system of hot-water supply.]

Boiler explosions are due to obstructions in the pipes. If the
expansion pipe and the cold-water supply pipe freeze, there is danger of
a slight accumulation of steam; and if one of the circulation pipes is
also blocked, steam must generate until "something has to go,"[38] which
is naturally the boiler. Assuming that the pipes are quite full to the
points of obstruction, the fracture would result from the expansion of
the water. Steam cannot generate unless there be a space above the
water. But the expanding water has stored up the heat which would have
raised steam, and the moment expansion begins after fracture this energy
is suddenly let loose. Steam forms instantaneously, augmenting the
effects of the explosion. From this it will be gathered that all pipes
should be properly protected against frost; especially near the roof.

Another cause of disaster is the _furring up_ of the pipes with the lime
deposited by hard water when heated. When hard water is used, the pipes
will sooner or later be blocked near the boiler; and as the deposit is
too hard to be scraped away, periodical renewals are unavoidable.


HOW A LAMP WORKS.

From heating we turn to lighting, and first to the ordinary paraffin
lamp. The two chief things to notice about this are the wick and the
chimney. The wick, being made of closely-woven cotton, draws up the oil
by what is known as _capillary attraction_. If you dip the ends of two
glass tubes, one half an inch, the other one-eighth of an inch in
diameter, into a vessel of water, you will notice that the water rises
higher in the smaller tube. Or get two clean glass plates and lay them
face to face, touching at one end, but kept slightly apart at the other
by some small object. If they are partly submerged perpendicularly, the
water will rise between the plates--furthest on the side at which the
two plates touch, and less and less as the other edge is approached. The
tendency of liquids to rise through porous bodies is a phenomenon for
which we cannot account.

Mineral oil contains a large proportion of carbon and hydrogen; it is
therefore termed hydro-carbon. When oil reaches the top of a lighted
wick, the liquid is heated until it turns into gas. The carbon and
hydrogen unite with the oxygen of the air. Some particles of the carbon
apparently do not combine at once, and as they pass through the fiery
zone of the flame are heated to such a temperature as to become highly
luminous. It is to produce these light-rays that we use a lamp, and to
burn our oil efficiently we must supply the flame with plenty of oxygen,
with more than it could naturally obtain. So we surround it with a
transparent chimney of special glass. The air inside the chimney is
heated, and rises; fresh air rushes in at the bottom, and is also heated
and replaced. As the air passes through, the flame seizes on the oxygen.
If the wick is turned up until the flame becomes smoky and flares, the
point has been passed at which the induced chimney draught can supply
sufficient oxygen to combine with the carbon of the vapour, and the
"free" carbon escapes as smoke.

The blower-plate used to draw up a fire (Fig. 194) performs exactly the
same function as the lamp chimney, but on a larger scale. The plate
prevents air passing straight up the chimney over the coals, and compels
it to find a way through the fire itself to replace the heated air
rising up the chimney.

[Illustration: FIG. 194.--Showing how a blower-plate draws up the
fire.]


GAS AND GASWORKS.

A lamp is an apparatus for converting hydro-carbon mineral oil into gas
and burning it efficiently. The gas-jet burns gases produced by driving
off hydro-carbon vapours from coal in apparatus specially designed for
the purpose. Gas-making is now, in spite of the competition of electric
lighting, so important an industry that we shall do well to glance at
the processes which it includes. Coal gas may be produced on a very
small scale as follows:--Fill a tin canister (the joints of which have
been made by folding the metal, not by soldering) with coal, clap on the
lid, and place it, lid downwards, in a bright fire, after punching a
hole in the bottom. Vapour soon begins to issue from the hole. This is
probably at first only steam, due to the coal being more or less damp.
But if a lighted match be presently applied the vapour takes fire,
showing that coal gas proper is coming off. The flame lasts for a long
time. When it dies the canister may be removed and the contents
examined. Most of the carbon remains in the form of _coke_. It is bulk
for bulk much lighter than coal, for the hydrogen, oxygen, and other
gases, and some of the carbon have been driven off by the heat. The coke
itself burns if placed in a fire, but without any smoke, such as issues
from coal.

[Illustration: FIG. 195.--Sketch of the apparatus used in the
manufacture of coal gas.]

Our home-made gas yields a smoky and unsatisfactory flame, owing to the
presence of certain impurities--ammonia, tar, sulphuretted hydrogen, and
carbon bisulphide. A gas factory must be equipped with means of getting
rid of these objectionable constituents. Turning to Fig. 195, which
displays very diagrammatically the main features of a gas plant, we
observe at the extreme right the _retorts_, which correspond to our
canister. These are usually long fire-brick tubes of D-section, the flat
side at the bottom. Under each is a furnace, the flames of which play on
the bottom, sides, and inner end of the retort. The outer end projecting
beyond the brickwork seating has an iron air-tight door for filling the
retort through, immediately behind which rises an iron exit pipe, A, for
the gases. Tar, which vaporizes at high temperatures, but liquefies at
ordinary atmospheric heat, must first be got rid of. This is effected by
passing the gas through the _hydraulic main_, a tubular vessel half full
of water running the whole length of the retorts. The end of pipe A
dips below the surface of the water, which condenses most of the tar and
steam. The partly-purified gas now passes through pipe B to the
_condensers_, a series of inverted U-pipes standing on an iron chest
with vertical cross divisions between the mouths of each U. These
divisions dip into water, so that the gas has to pass up one leg of a U,
down the other, up the first leg of the second pipe, and so on, till all
traces of the tar and other liquid constituents have condensed on the
inside of the pipe, from which they drop into the tank below.

The next stage is the passage of the _scrubber_, filled with coke over
which water perpetually flows. The ammonia gas is here absorbed. There
still remain the sulphuretted hydrogen and the carbon bisulphide, both
of which are extremely offensive to the nostrils. Slaked lime, laid on
trays in an air-tight compartment called the _lime purifier_, absorbs
most of the sulphurous elements of these; and the coal gas is then fit
for use. On leaving the purifiers it flows into the _gasometer_, or
gasholder, the huge cake-like form of which is a very familiar object in
the environs of towns. The gasometer is a cylindrical box with a domed
top, but no bottom, built of riveted steel plates. It stands in a
circular tank of water, so that it may rise and fall without any escape
of gas. The levity of the gas, in conjunction with weights attached to
the ends of chains working over pulleys on the framework surrounding the
holder, suffices to raise the holder.

[Illustration: FIG. 196.--The largest gasholder in the world: South
Metropolitan Gas Co., Greenwich Gas Works. Capacity, 12,158,600 cubic
feet.]

Some gasometers have an enormous capacity. The record is at present
held by that built for the South Metropolitan Gas Co., London, by
Messrs. Clayton & Son of Leeds. This monster (of which we append an
illustration, Fig. 196) is 300 feet in diameter and 180 feet high. When
fully extended it holds 12,158,600 cubic feet of gas. Owing to its
immense size, it is built on the telescopic principle in six "lifts," of
30 feet deep each. The sides of each lift, or ring, except the topmost,
have a section shaped somewhat like the letter N. Two of the members
form a deep, narrow cup to hold water, in which the "dip" member of the
ring above it rises and falls.

[Illustration: FIG. 197.--Drawing retorts. (_Photo by F. Marsh._)]


AUTOMATIC STOKING.

The labour of feeding the retorts with coal and removing the coke is
exceedingly severe. In the illustration on p. 400 (made from a very fine
photograph taken by Mr. F. Marsh of Clifton) we see a man engaged in
"drawing" the retorts through the iron doors at their outer ends.
Automatic machinery is now used in large gasworks for both operations.
One of the most ingenious stokers is the De Brouwer, shown at work in
Fig. 198. The machine is suspended from an overhead trolley running on
rails along the face of the retorts. Coal falls into a funnel at the top
of the telescopic pipe P from hoppers in the story above, which have
openings, H H, controlled by shutters. The coal as it falls is caught by
a rubber belt working round part of the circumference of the large
wheel W and a number of pulleys, and is shot into the mouth of the
retort. The operator is seen pulling the handle which opens the shutter
of the hopper above the feed-tube, and switching on the 4 h.p. electric
motor which drives the belt and moves the machine about. One of these
feeders will charge a retort 20 feet long in twenty-two seconds.

[Illustration: FIG. 198.--De Brouwer automatic retort charger.]


A GAS GOVERNOR.

Some readers may have noticed that late at night a gas-jet, which a few
hours before burned with a somewhat feeble flame when the tap was turned
fully on, now becomes more and more vigorous, and finally may flare up
with a hissing sound. This is because many of the burners fed by the
main supplying the house have been turned off, and consequently there is
a greater amount of gas available for the jets still burning, which
therefore feel an increased pressure. As a matter of fact, the pressure
of gas in the main is constantly varying, owing partly to the
irregularity of the delivery from the gasometer, and partly to the fact
that the number of burners in action is not the same for many minutes
together. It must also be remembered that houses near the gasometer end
of the main will receive their gas at a higher pressure than those at
the other end. The gas stored in the holders may be wanted for use in
the street lamps a few yards away, or for other lamps several miles
distant. It is therefore evident that if there be just enough pressure
to give a good supply to the nearest lamp, there will be too little a
short distance beyond it, and none at all at the extreme point; so that
it is necessary to put on enough pressure to overcome the friction on
all these miles of pipe, and give just enough gas at the extreme end. It
follows that at all intermediate points the pressure is excessive. Gas
of the average quality is burned to the greatest advantage, as regards
its light-giving properties, when its pressure is equal to that of a
column of water half an inch high, or about 1/50 lb. to the square inch.
With less it gives a smoky, flickering light, and with more the
combustion is also imperfect.

[Illustration: FIG. 199.]

Every house supply should therefore be fitted with a gas governor, to
keep the pressure constant. A governor frequently used, the Stott, is
shown in section in Fig. 199. Gas enters from the main on the right, and
passes into a circular elbow, D, which has top and bottom apertures
closed by the valves V V. Attached to the valve shaft is a large
inverted cup of metal, the tip of which is immersed in mercury. The
pressure at which the governor is to act is determined by the weights W,
with which the valve spindle is loaded at the top. As soon as this
pressure is exceeded, the gas in C C lifts the metal cup, and V V are
pressed against their seats, so cutting off the supply. Gas cannot
escape from C C, as it has not sufficient pressure to force its way
through the mercury under the lip of the cup. Immediately the pressure
in C C falls, owing to some of the gas being used up, the valves open
and admit more gas. When the fluctuations of pressure are slight, the
valves never close completely, but merely throttle the supply until the
pressure beyond them falls to its proper level--that is, they pass just
as much gas as the burners in use can consume at the pressure arranged
for.

Governors of much larger size, but working on much the same principle,
are fitted to the mains at the point where they leave the gasometers.
They are not, however, sensitive to local fluctuations in the pipes,
hence the necessity for separate governors in the house between the
meter and the burners.


THE GAS-METER

commonly used in houses acts on the principle shown in Fig. 200. The
air-tight casing is divided by horizontal and vertical divisions into
three gas-chambers, B, C, and D. Gas enters at A, and passes to the
valve chamber B. The slide-valves of this allow it to pass into C and D,
and also into the two circular leather bellows E, F, which are attached
to the central division G, but are quite independent of one another.

[Illustration: FIG. 200.--Sketch of the bellows and chambers of a "dry"
gas meter.]

We will suppose that in the illustration the valves are admitting gas to
chamber C and bellows F. The pressure in C presses the circular head of
E towards the division G, expelling the contents of the bellows through
an outlet pipe (not shown) to the burners in operation within the house.
Simultaneously the inflation of F forces the gas in chamber D also
through the outlet. The head-plates of the bellows are attached to rods
and levers (not shown) working the slide-valves in B. As soon as E is
fully in, and F fully expanded, the valves begin to open and put the
inlet pipe in communication with D and E, and allow the contents of F
and C to escape to the outlet. The movements of the valve mechanism
operate a train of counting wheels, visible through a glass window in
the side of the case. As the bellows have a definite capacity, every
stroke that they give means that a certain volume of gas has been
ejected either from them or from the chambers in which they move: this
is registered by the counter. The apparatus practically has two
double-action cylinders (of which the bellows ends are the pistons)
working on the same principle as the steam-cylinder (Fig. 21). The
valves have three ports--the central, or exhaust, leading to the outlet,
the outer ones from the inlet. The bellows are fed through channels in
the division G.


INCANDESCENT GAS LIGHTING.

The introduction of the electric arc lamp and the incandescent glow-lamp
seemed at one time to spell the doom of gas as an illuminating agent.
But the appearance in 1886 of the Welsbach _incandescent mantle_ for
gas-burners opened a prosperous era in the history of gas lighting.

The luminosity of a gas flame depends on the number of carbon particles
liberated within it, and the temperature to which these particles can be
heated as they pass through the intensely hot outside zone of the flame.
By enriching the gas in carbon more light is yielded, up to a certain
point, with a flame of a given temperature. To increase the heat of the
flame various devices were tried before the introduction of the
incandescent mantle, but they were found to be too short-lived to have
any commercial value. Inventors therefore sought for methods by which
the emission of light could be obtained from coal gas independently of
the incandescence of the carbon particles in the flame itself; and step
by step it was discovered that gas could be better employed merely as a
heating agent, to raise to incandescence substances having a higher
emissivity of light than carbon.

Dr. Auer von Welsbach found that the substances most suitable for
incandescent mantles were the oxides of certain rare metals, _thorium_,
and _cerium_. The mantle is made by dipping a cylinder of cotton net
into a solution of nitrate of thorium and cerium, containing 99 per
cent. of the former and 1 per cent. of the latter metal. When the fibres
are sufficiently soaked, the mantle is withdrawn, squeezed, and placed
on a mould to dry. It is next held over a Bunsen gas flame and the
cotton is burned away, while the nitrates are converted into oxides. The
mantle is now ready for use, but very brittle. So it has to undergo a
further dipping, in a solution of gun-cotton and alcohol, to render it
tough enough for packing. When it is required for use, it is suspended
over the burner by an asbestos thread woven across the top, a light is
applied to the bottom, and the collodion burned off, leaving nothing but
the heat-resisting oxides.

The burner used with a mantle is constructed on the Bunsen principle.
The gas is mixed, as it emerges from the jet, with sufficient air to
render its combustion perfect. All the carbon is burned, and the flame,
though almost invisible, is intensely hot. The mantle oxides convert the
heat energy of the flame into light energy. This is proved not only by
the intense whiteness of the mantle, but by the fact that the heat
issuing from the chimney of the burner is not nearly so great when the
mantle is in position as when it is absent.

The incandescent mantle is more extensively used every year. In Germany
90 per cent. of gas lighting is on the incandescent system, and in
England about 40 per cent. We may notice, as an interesting example of
the fluctuating fortunes of invention, that the once doomed gas-burner
has, thanks to Welsbach's mantle, in many instances replaced the
incandescent electric lamps that were to doom it.

[38] If, of course, there is no safety-valve in proper working order
included in the installation.




Chapter XX.

VARIOUS MECHANISMS.

     CLOCKS AND WATCHES:--A short history of timepieces--The
     construction of timepieces--The driving power--The
     escapement--Compensating pendulums--The spring balance--The
     cylinder escapement--The lever escapement--Compensated
     balance-wheels--Keyless winding mechanism for watches--The hour
     hand train. LOCKS:--The Chubb lock--The Yale lock. THE CYCLE:--The
     gearing of a cycle--The free wheel--The change-speed gear.
     AGRICULTURAL MACHINES:--The threshing-machine--Mowing-machines.
     SOME NATURAL PHENOMENA:--Why sun-heat varies in intensity--The
     tides--Why high tide varies daily.

CLOCKS AND WATCHES.


A SHORT HISTORY OF TIMEPIECES.

The oldest device for measuring time is the sun-dial. That of Ahaz
mentioned in the Second Book of Kings is the earliest dial of which we
have record. The obelisks of the Egyptians and the curious stone pillars
of the Druidic age also probably served as shadow-casters.

The clepsydra, or water-clock, also of great antiquity, was the first
contrivance for gauging the passage of the hours independently of the
motion of the earth. In its simplest form it was a measure into which
water fell drop by drop, hour levels being marked on the inside.
Subsequently a very simple mechanism was added to drive a pointer--a
float carrying a vertical rack, engaging with a cog on the pointer
spindle; or a string from the float passed over a pulley attached to the
pointer and rotated it as the float rose, after the manner of the wheel
barometer (Fig. 153). In 807 A.D. Charlemagne received from the King of
Persia a water-clock which struck the hours. It is thus described in
Gifford's "History of France":--"The dial was composed of twelve small
doors, which represented the division of the hours. Each door opened at
the hour it was intended to represent, and out of it came a small number
of little balls, which fell one by one, at equal distances of time, on a
brass drum. It might be told by the eye what hour it was by the number
of doors that were open, and by the ear by the number of balls that
fell. When it was twelve o'clock twelve horsemen in miniature issued
forth at the same time and shut all the doors."

Sand-glasses were introduced about 330 A.D. Except for special
purposes, such as timing sermons and boiling eggs, they have not been of
any practical value.

The clepsydra naturally suggested to the mechanical mind the idea of
driving a mechanism for registering time by the force of gravity acting
on some body other than water. The invention of the _weight-driven
clock_ is attributed, like a good many other things, to Archimedes, the
famous Sicilian mathematician of the third century B.C.; but no record
exists of any actual clock composed of wheels operated by a weight prior
to 1120 A.D. So we may take that year as opening the era of the clock as
we know it.

About 1500 Peter Hele of Nuremberg invented the _mainspring_ as a
substitute for the weight, and the _watch_ appeared soon afterwards
(1525 A.D.). The pendulum was first adopted for controlling the motion
of the wheels by Christian Huygens, a distinguished Dutch mechanician,
in 1659.

To Thomas Tompion, "the father of English watchmaking," is ascribed the
honour of first fitting a _hairspring_ to the escapement of a watch, in
or about the year 1660. He also introduced the _cylinder escapement_ now
so commonly used in cheap watches. Though many improvements have been
made since his time, Tompion manufactured clocks and watches which were
excellent timekeepers, and as a reward for the benefits conferred on his
fellows during his lifetime, he was, after death, granted the
exceptional honour of a resting-place in Westminster Abbey.


THE CONSTRUCTION OF TIMEPIECES.

A clock or watch contains three main elements:--(1) The source of power,
which may be a weight or a spring; (2) the train of wheels operated by
the driving force; (3) the agent for controlling the movements of the
train--this in large clocks is usually a pendulum, in small clocks and
watches a hairspring balance. To these may be added, in the case of
clocks, the apparatus for striking the hour.


THE DRIVING POWER.

_Weights_ are used only in large clocks, such as one finds in halls,
towers, and observatories. The great advantage of employing weights is
that a constant driving power is exerted. _Springs_ occupy much less
room than weights, and are indispensable for portable timepieces. The
employment of them caused trouble to early experimenters on account of
the decrease in power which necessarily accompanies the uncoiling of a
wound-up spring. Jacob Zech of Prague overcame the difficulty in 1525 by
the invention of the _fusee_, a kind of conical pulley interposed
between the barrel, or circular drum containing the mainspring, and the
train of wheels which the spring has to drive. The principle of the
"drum and fusee" action will be understood from Fig. 201. The mainspring
is a long steel ribbon fixed at one end to an arbor (the watchmaker's
name for a spindle or axle), round which it is tightly wound. The arbor
and spring are inserted in the barrel. The arbor is prevented from
turning by a ratchet, B, and click, and therefore the spring in its
effort to uncoil causes the barrel to rotate.

[Illustration: FIG. 201.]

A string of catgut (or a very fine chain) is connected at one end to
the circumference of the drum, and wound round it, the other end being
fixed to the larger end of the fusee, which is attached to the
driving-wheel of the watch or clock by the intervention of a ratchet and
click (not shown). To wind the spring the fusee is turned backward by
means of a key applied to the square end A of the fusee arbor, and this
draws the string from off the drum on to the fusee. The force of the
spring causes the fusee to rotate by pulling the string off it, coil by
coil, and so drives the train of wheels. But while the mainspring, when
fully wound, turns the fusee by uncoiling the string from the smallest
part of the fusee, it gets the advantage of the larger radius as its
energy becomes lessened.

The fusee is still used for marine chronometers, for some clocks that
have a mainspring and pendulum, and occasionally for watches. In the
latter it has been rendered unnecessary by the introduction of the
_going-barrel_ by Swiss watchmakers, who formed teeth on the edge of the
mainspring barrel to drive the train of wheels. This kind of drum is
called "going" because it drives the watch during the operation of
winding, which is performed by rotating the drum arbor to which the
inner end of the spring is attached. A ratchet prevents the arbor from
being turned backwards by the spring. The adoption of the going-barrel
has been made satisfactory by the improvements in the various escapement
actions.


THE ESCAPEMENT.

[Illustration: FIG. 202.]

The spring or weight transmits its power through a train of cogs to the
_escapement_, or device for regulating the rate at which the wheels are
to revolve. In clocks a _pendulum_ is generally used as the controlling
agent. Galileo, when a student at Pisa, noticed that certain hanging
lamps in the cathedral there swung on their cords at an equal rate; and
on investigation he discovered the principle that the shorter a pendulum
is the more quickly will it swing to and fro. As has already been
observed, Huygens first applied the principle to the governing of
clocks. In Fig. 202 we have a simple representation of the "dead-beat"
escapement commonly used in clocks. The escape-wheel is mounted on the
shaft of the last cog of the driving train, the pallet on a spindle
from which depends a split arm embracing the rod and the pendulum. We
must be careful to note that the pendulum _controls_ motion only; it
does not cause movement.

The escape-wheel revolves in a clockwise direction. The two pallets _a_
and _b_ are so designed that only one can rest on the teeth at one time.
In the sketch the sloping end of _b_ has just been forced upwards by the
pressure of a tooth. This swings the pallet and the pendulum. The
momentum of the latter causes _a_ to descend, and at the instant when
_b_ clears its tooth _a_ catches and holds another. The left-hand side
of _a_, called the _locking-face_, is part of a circle, so that the
escape-wheel is held motionless as long as it touches _a_: hence the
term, "dead beat"--that is, brought to a dead stop. As the pendulum
swings back, to the left, under the influence of gravity, _a_ is raised
and frees the tooth. The wheel jerks round, and another tooth is caught
by the locking-face of _b_. Again the pendulum swings to the right, and
the sloping end of _b_ is pushed up once more, giving the pendulum fresh
impetus. This process repeats itself as long as the driving power
lasts--for weeks, months, or years, as the case may be, and the
mechanism continues to be in good working order.


COMPENSATING PENDULUMS.

Metal expands when heated; therefore a steel pendulum which is of the
exact length to govern a clock correctly at a temperature of 60° would
become too long at 80°, and slow the clock, and too short at 40°, and
cause it to gain. In common clocks the pendulum rod is often made of
wood, which maintains an almost constant length at all ordinary
temperatures. But for very accurate clocks something more efficient is
required. Graham, the partner of Thomas Tompion, took advantage of the
fact that different kinds of metal have different ratios of expansion to
produce a _self-compensating_ pendulum on the principle illustrated by
Fig. 203. He used steel for the rod, and formed the _bob_, or weighted
end, of a glass jar containing mercury held in a stirrup; the mercury
being of such a height that, as the pendulum rod lengthened with a rise
of temperature, the mercury expanded _upwards_ sufficiently to keep the
distance between the point of suspension and the centre of gravity of
the bob always the same. With a fall of temperature the rod shortened,
while the mercury sank in the jar. This device has not been improved
upon, and is still used in observatories and other places where
timekeepers of extreme precision are required. The milled nut S in Fig.
203 is fitted at the end of the pendulum rod to permit the exact
adjustment of the pendulum's length.

For watches, chronometers, and small clocks


THE SPRING BALANCE

takes the place of the pendulum. We still have an escape-wheel with
teeth of a suitable shape to give impulses to the controlling agent.
There are two forms of spring escapement, but as both employ a
hairspring and balance-wheel we will glance at these before going
further.

[Illustration: FIG. 203.]

The _hairspring_ is made of very fine steel ribbon, tempered to extreme
elasticity, and shaped to a spiral. The inner end is attached to the
arbor of the _balance-wheel_, the outer end to a stud projecting from
the plate of the watch. When the balance-wheel, impelled by the
escapement, rotates, it winds up the spring. The energy thus stored
helps the wheel to revolve the other way during the locking of a tooth
of the escape-wheel. The time occupied by the winding and the unwinding
depends upon the length of the spring. The strength of the impulse makes
no difference. A strong impulse causes the spring to coil itself up more
than a weak impulse would; but inasmuch as more energy is stored the
process of unwinding is hastened. To put the matter very simply--a
strong impulse moves the balance-wheel further, but rotates it quickly;
a weak impulse moves it a shorter distance, but rotates it slowly. In
fact, the principle of the pendulum is also that of the hairspring; and
the duration of a vibration depends on the length of the rod in the one
case, and of the spring in the other.

Motion is transmitted to the balance by one of two methods. Either (1)
directly, by a cylinder escapement; or (2) indirectly, through a lever.

[Illustration: FIG. 204.--"Cylinder" watch escapement.]


THE CYLINDER ESCAPEMENT

is seen in Fig. 204. The escape-wheel has sharp teeth set on stalks.
(One tooth is removed to show the stalk.) The balance-wheel is mounted
on a small steel cylinder, with part of the circumference cut away at
the level of the teeth, so that if seen from above it would appear like
_a_ in our illustration. A tooth is just beginning to shove its point
under the nearer edge of the opening. As it is forced forwards, _b_ is
revolved in a clockwise direction, winding up the hairspring. When the
tooth has passed the nearer edge it flies forward, striking the inside
of the further wall of the cylinder, which holds it while the spring
uncoils. The tooth now pushes its way past the other edge, accelerating
the unwinding, and, as it escapes, the next tooth jumps forward and is
arrested by the outside of the cylinder. The balance now reverses its
motion, is helped by the tooth, is wound up, locks the tooth, and so on.


THE LEVER ESCAPEMENT

is somewhat more complicated. The escape-wheel teeth are locked and
unlocked by the pallets P P^1 projecting from a lever which moves on a
pivot (Fig. 205). The end of the lever is forked, and has a square notch
in it. On the arbor of the balance-wheel is a roller, or plate, R, which
carries a small pin, I. Two pins, B B, projecting from the plate of the
watch prevent the lever moving too far. We must further notice the
little pin C on the lever, and a notch in the edge of the roller.

[Illustration: FIG. 205.--"Lever" watch escapement.]

In the illustration a tooth has just passed under the "impulse face" _b_
of P^1. The lever has been moved upwards at the right end; and its
forked end has given an impulse to R, and through it to the
balance-wheel. The spring winds up. The pin C prevents the lever
dropping, because it no longer has the notch opposite to it, but presses
on the circumference of R. As the spring unwinds it strikes the lever at
the moment when the notch and C are opposite. The lever is knocked
downwards, and the tooth, which had been arrested by the locking-face
_a_ of pallet P, now presses on the impulse face _b_, forcing the left
end of the lever up. The impulse pin I receives a blow, assisting the
unwinding of the spring, and C again locks the lever. The same thing is
repeated in alternate directions over and over again.


COMPENSATING BALANCE-WHEELS.

The watchmaker has had to overcome the same difficulty as the clockmaker
with regard to the expansion of the metal in the controlling agent. When
a metal wheel is heated its spokes lengthen, and the rim recedes from
the centre. Now, let us suppose that we have two rods of equal weight,
one three feet long, the other six feet long. To an end of each we
fasten a 2-lb. weight. We shall find it much easier to wave the shorter
rod backwards and forwards quickly than the other. Why? Because the
weight of the longer rod has more leverage over the hand than has that
of the shorter rod. Similarly, if, while the mass of the rim of a wheel
remains constant, the length of the spokes varies, the effort needed to
rotate the wheel to and fro at a constant rate must vary also. Graham
got over the difficulty with a rod by means of the compensating
pendulum. Thomas Earnshaw mastered it in wheels by means of the
_compensating balance_, using the same principle--namely, the unequal
expansion of different metals. Any one who owns a compensated watch will
see, on stopping the tiny fly-wheel, that it has two spokes (Fig. 206),
each carrying an almost complete semicircle of rim attached to it. A
close examination shows that the rim is compounded of an outer strip of
brass welded to an inner lining of steel. The brass element expands more
with heat and contracts more with cold than steel; so that when the
spokes become elongated by a rise of temperature, the pieces bend
inwards at their free ends (Fig. 207); if the temperature falls, the
spokes are shortened, and the rim pieces bend outwards (Fig. 208).[39]
This ingenious contrivance keeps the leverage of the rim constant
within very fine limits. The screws S S are inserted in the rim to
balance it correctly, and very fine adjustment is made by means of the
four tiny weights W W. In ships' chronometers,[40] the rim pieces are
_sub_-compensated towards their free ends to counteract slight errors in
the primary compensation. So delicate is the compensation that a daily
loss or gain of only half a second is often the limit of error.

[Illustration: FIG. 206. FIG. 207. FIG. 208. A "compensating" watch
balance, at normal, super-normal, and sub-normal temperatures.]


KEYLESS WINDING MECHANISM FOR WATCHES.

The inconvenience attaching to a key-wound watch caused the Swiss
manufacturers to put on the market, in 1851, watches which dispensed
with a separate key. Those of our readers who carry keyless watches will
be interested to learn how the winding and setting of the hands is
effected by the little serrated knob enclosed inside the pendant ring.

There are two forms of "going-barrel" keyless mechanism--(1) The rocking
bar; (2) the shifting sleeve. The _rocking bar_ device is shown in Figs.
209, 210. The milled head M turns a cog, G, which is always in gear with
a cog, F. This cog gears with two others, A and B, mounted at each end
of the rocker R, which moves on pivot S. A spring, S P, attached to the
watch plate presses against a small stud on the rocking bar, and keeps A
normally in gear with C, mounted on the arbor of the mainspring.

[Illustration: FIG. 209.--The winding mechanism of a keyless watch.]

To wind the watch, M is turned so as to give F an anti-clockwise motion.
The teeth of F now press A downwards and keep it in gear with C while
the winding is done. A spring click (marked solid black) prevents the
spring uncoiling (Fig. 209). If F is turned in a clockwise direction it
lifts A and prevents it biting the teeth of C, and no strain is thrown
on C.

To set the hands, the little push-piece P is pressed inwards by the
thumb (Fig. 210) so as to depress the right-hand end of R and bring B
into gear with D, which in turn moves E, mounted on the end of the
minute-hand shaft. The hands can now be moved in either direction by
turning M. On releasing the push-piece the winding-wheels engage again.

The _shifting sleeve_ mechanism has a bevel pinion in the place of G
(Fig. 209) gearing with the mainspring cog. The shaft of the knob M is
round where it passes through the bevel and can turn freely inside it,
but is square below. On the square part is mounted a little sliding
clutch with teeth on the top corresponding with the other teeth on the
under side of the bevel-wheel, and teeth similar to those of G (Fig.
209) at the end. The clutch has a groove cut in the circumference, and
in this lies the end of a spring lever which can be depressed by the
push-piece. The mechanism much resembles on a small scale the motor car
changing gear (Fig. 49). Normally, the clutch is pushed up the square
part of the knob shaft by the spring so as to engage with the bevel and
the winding-wheels. On depressing the clutch by means of the push-piece
it gears with the minute-hand pinion, and lets go of the bevel.

[Illustration: FIG. 210.--The hand-setting mechanism in action.]

In one form of this mechanism the push-piece is dispensed with, and the
minute-wheel pinion is engaged by pulling the knob upwards.


THE HOUR-HAND TRAIN.

[Illustration: FIG. 211.--The hour-hand train of a clock.]

The teeth of the mainspring drum gear with a cog on the minute-hand
shaft, which also carries one of the cogs of the escapement train. The
shaft is permitted by the escapement to revolve once an hour. Fig. 211
shows diagrammatically how this is managed. The hour-hand shaft A (solid
black) can be moved round inside the cog B, driven by the mainspring
drum. It carries a cog, C. This gears with a cog, D, having three times
as many teeth. The cog E, united to D, drives cog F, having four times
as many teeth as E. To F is attached the collar G of the hour-hand. F
and G revolve outside the minute-hand shaft. On turning A, C turns D and
E, E turns F and the hour-hand, which revolves 1/3 of 1/4 = 1/12 as fast
as A.[41]

       *       *       *       *       *

LOCKS.

On these unfortunately necessary mechanisms a great deal of ingenuity
has been expended. With the advance of luxury and the increased worship
of wealth, it becomes more and more necessary to guard one's belongings
against the less scrupulous members of society.

[Illustration: FIG. 212.]

The simplest form of lock, such as is found in desks and very cheap
articles, works on the principle shown in Fig. 212. The bolt is split at
the rear, and the upper part bent upwards to form a spring. The under
edge has two notches cut in it, separated by a curved excrescence. The
key merely presses the bolt upwards against the spring, until the notch,
engaging with the frame, moves it backwards or forwards until the spring
drives the tail down into the other notch. This primitive device
affords, of course, very little security. An advance is seen in the

TUMBLER LOCK.

[Illustration: FIG. 213.]

The bolt now can move only in a horizontal direction. It has an opening
cut in it with two notches (Figs. 213, 214). Behind the bolt lies the
_tumbler_ T (indicated by the dotted line), pivoted at the angle on a
pin. From the face of the tumbler a stud, S, projects through the hole
in the bolt. This stud is forced into one or other of the notches by the
spring, S^1, which presses on the tail of the tumbler.

[Illustration: FIG. 214.]

In Fig. 213 the key is about to actuate the locking mechanism. The next
diagram (Fig. 214) shows how the key, as it enters the notch on the
lower side of the bolt to move it along, also raises the tumbler stud
clear of the projection between the two notches. By the time that the
bolt has been fully "shot," the key leaves the under notch and allows
the tumbler stud to fall into the rear locking-notch.

A lock of this type also can be picked very easily, as the picker has
merely to lift the tumbler and move the bolt along. Barron's lock,
patented in 1778, had two tumblers and two studs; and the opening in the
bolt had notches at the top as well as at the bottom (Fig. 215). This
made it necessary for both tumblers to be raised simultaneously to
exactly the right height. If either was not lifted sufficiently, a stud
could not clear its bottom notch; if either rose too far, it engaged an
upper notch. The chances therefore were greatly against a wrong key
turning the lock.

[Illustration: FIG. 215.--The bolt of a Barron lock.]

THE CHUBB LOCK

is an amplification of this principle. It usually has several tumblers
of the shape shown in Fig. 216. The lock stud in these locks projects
from the bolt itself, and the openings, or "gates," through which the
stud must pass as the lock moves, are cut in the tumblers. It will be
noticed that the forward notch of the tumbler has square serrations in
the edges. These engage with similar serrations in the bolt stud and
make it impossible to raise the tumbler if the bolt begins to move too
soon when a wrong key is inserted.

[Illustration: FIG. 216.--Tumbler of Chubb lock.]

Fig. 217 is a Chubb key with eight steps. That nearest the head (8)
operates a circular revolving curtain, which prevents the introduction
of picking tools when a key is inserted and partly turned, as the key
slot in the curtain is no longer opposite that in the lock. Step 1 moves
the bolt.

[Illustration: FIG. 217.--A Chubb key.]

In order to shoot the bolt the height of the key steps must be so
proportioned to the depth of their tumblers that all the gates in the
tumblers are simultaneously raised to the right level for the stud to
pass through them, as in Fig. 218. Here you will observe that the
tumbler D on the extreme right (lifted by step 2 of the key) has a stud,
D S, projecting from it over the other tumblers. This is called the
_detector tumbler_. If a false key or picking tool is inserted it is
certain to raise one of the tumblers too far. The detector is then
over-lifted by the stud D S, and a spring catch falls into a notch at
the rear. It is now impossible to pick the lock, as the detector can be
released only by the right key shooting the bolt a little further in the
locking direction, when a projection on the rear of the bolt lifts the
catch and allows the tumbler to fall. The detector also shows that the
lock has been tampered with, since even the right key cannot move the
bolt until the overlocking has been performed.

[Illustration: FIG. 218.--A Chubb key raising all the tumblers to the
correct height.]

Each tumbler step of a large Chubb key can be given one of thirty
different heights; the bolt step one of twenty. By merely transposing
the order of the steps in a six-step key it is possible to get 720
different combinations. By diminishing or increasing the heights the
possible combinations may be raised to the enormous total of 7,776,000!

[Illustration: FIG. 219.--Section of a Yale lock.]


THE YALE LOCK,

which comes from America, works on a quite different system. Its most
noticeable feature is that it permits the use of a very small key,
though the number of combinations possible is still enormous (several
millions). In our illustrations (Figs. 219, 220, 221) we show the
mechanism controlling the turning of the key. The keyhole is a narrow
twisted slot in the face of a cylinder, G (Fig. 219), which revolves
inside a larger fixed cylinder, F. As the key is pushed in, the notches
in its upper edge raise up the pins A^1, B^1, C^1, D^1, E^1,
until their tops exactly reach the surface of G, which can now be
revolved by the key in Fig. 220, and work the bolt through the medium of
the arm H. (The bolt itself is not shown.) If a wrong key is inserted,
either some of the lower pins will project upwards into the fixed
cylinder F (see Fig. 221), or some of the pins in F will sink into G. It
is then impossible to turn the key.

[Illustration: FIG. 220.--Yale key turning.]

There are other well-known locks, such as those invented by Bramah and
Hobbs. But as these do not lend themselves readily to illustration no
detailed account can be given. We might, however, notice the _time_
lock, which is set to a certain hour, and can be opened by the right key
or a number of keys in combination only when that hour is reached.
Another very interesting device is the _automatic combination_ lock.
This may have twenty or more keys, any one of which can lock it; but the
same one must be used to _un_lock it, as the key automatically sets the
mechanism in favour of itself. With such a lock it would be possible to
have a different key for every day in the month; and if any one key got
into wrong hands it would be useless unless it happened to be the one
which last locked the lock.

[Illustration: FIG. 221.--The wrong key inserted. The pins do not allow
the lock to be turned.]

       *       *       *       *       *

THE CYCLE.

There are a few features of this useful and in some ways wonderful
contrivance which should be noticed. First,


THE GEARING OF A CYCLE.

To a good many people the expression "geared to 70 inches," or 65, or
80, as the case may be, conveys nothing except the fact that the higher
the gear the faster one ought to be able to travel. Let us therefore
examine the meaning of such a phrase before going farther.

The safety cycle is always "geared up"--that is, one turn of the pedals
will turn the rear wheel more than once. To get the exact ratio of
turning speed we count the teeth on the big chain-wheel, and the teeth
on the small chain-wheel attached to the hub of the rear wheel, and
divide the former by the latter. To take an example:--The teeth are 75
and 30 in number respectively; the ratio of speed therefore = 75/30 =
5/2 = 2-1/2. One turn of the pedal turns the rear wheel 2-1/2 times. The
gear of the cycle is calculated by multiplying this result by the
diameter of the rear wheel in inches. Thus a 28-inch wheel would in this
case give a gear of 2-1/2 × 28 = 70 inches.

One turn of the pedals on a machine of this gear would propel the rider
as far as if he were on a high "ordinary" with the pedals attached
directly to a wheel 70 inches in diameter. The gearing is raised or
lowered by altering the number ratio of the teeth on the two
chain-wheels. If for the 30-tooth wheel we substituted one of 25 teeth
the gearing would be--

  75/25 × 28 inches = 84 inches.

A handy formula to remember is, gearing = T/_t_ × D, where T = teeth on
large chain-wheel; _t_ = teeth on small chain-wheel; and D = diameter of
driving-wheel in inches.

Two of the most important improvements recently added to the cycle
are--(1) The free wheel; (2) the change-speed gear.


THE FREE WHEEL

is a device for enabling the driving-wheel to overrun the pedals when
the rider ceases pedalling; it renders the driving-wheel "free" of the
driving gear. It is a ratchet specially suited for this kind of work.
From among the many patterns now marketed we select the Micrometer
free-wheel hub (Fig. 222), which is extremely simple. The
_ratchet-wheel_ R is attached to the hub of the driving-wheel. The small
chain-wheel (or "chain-ring," as it is often called) turns outside this,
on a number of balls running in a groove chased in the neck of the
ratchet. Between these two parts are the _pawls_, of half-moon shape.
The driving-wheel is assumed to be on the further side of the ratchet.
To propel the cycle the chain-ring is turned in a clockwise direction.
Three out of the six pawls at once engage with notches in the ratchet,
and are held tightly in place by the pressure of the chain-ring on their
rear ends. The other three are in a midway position.

[Illustration: FIG. 222.]

When the rider ceases to pedal, the chain-ring becomes stationary, but
the ratchet continues to revolve. The pawls offer no resistance to the
ratchet teeth, which push them up into the semicircular recesses in the
chain-ring. Each one rises as it passes over a tooth. It is obvious
that driving power cannot be transmitted again to the road wheel until
the chain-wheel is turned fast enough to overtake the ratchet.


THE CHANGE-SPEED GEAR.

A gain in speed means a loss in power, and _vice versâ_. By gearing-up a
cycle we are able to make the driving-wheel revolve faster than the
pedals, but at the expense of control over the driving-wheel. A
high-geared cycle is fast on the level, but a bad hill-climber. The
low-geared machine shows to disadvantage on the flat, but is a good
hill-climber. Similarly, the express engine must have large
driving-wheels, the goods engine small driving-wheels, to perform their
special functions properly.

In order to travel fast over level country, and yet be able to mount
hills without undue exertion, we must be able to do what the motorist
does--change gear. Two-speed and three-speed gears are now very commonly
fitted to cycles. They all work on the same principle, that of the
epicyclic train of cog-wheels, the mechanisms being so devised that the
hub turns more slowly than, at the same speed as, or faster than the
small chain-wheel,[42] according to the wish of the rider.

We do not propose to do more here than explain the principle of the
epicyclic train, which means "a wheel on (or running round) a wheel."
Lay a footrule on the table and roll a cylinder along it by the aid of a
second rule, parallel to the first, but resting on the cylinder. It will
be found that, while the cylinder advances six inches, the upper rule
advances twice that distance. In the absence of friction the work done
by the agent moving the upper rule is equal to that done in overcoming
the force which opposes the forward motion of the cylinder; and as the
distance through which the cylinder advances is only half that through
which the upper rule advances, it follows that the _force_ which must
act on the upper rule is only half as great as that overcome in moving
the cylinder. The carter makes use of this principle when he puts his
hand to the top of a wheel to help his cart over an obstacle.

[Illustration: FIG. 223.]

[Illustration: FIG. 224.]

[Illustration: FIG. 225.]

Now see how this principle is applied to the change-speed gear. The
lower rule is replaced by a cog-wheel, C (Fig. 223); the cylinder by a
cog, B, running round it; and the upper rule by a ring, A, with internal
teeth. We may suppose that A is the chain-ring, B a cog mounted on a pin
projecting from the hub, and C a cog attached to the fixed axle. It is
evident that B will not move so fast round C as A does. The amount by
which A will get ahead of B can be calculated easily. We begin with the
wheels in the position shown in Fig. 223. A point, I, on A is exactly
over the topmost point of C. For the sake of convenience we will first
assume that instead of B running round C, B is revolved on its axis for
one complete revolution in a clockwise direction, and that A and C move
as in Fig. 224. If B has 10 teeth, C 30, and A 40, A will have been
moved 10/40 = 1/4 of a revolution in a clockwise direction, and C 10/30
= 1/3 of a revolution in an anti-clockwise direction.

Now, coming back to what actually does happen, we shall be able to
understand how far A rotates round C relatively to the motion of B, when
C is fixed and B rolls (Fig. 225). B advances 1/3 of distance round C; A
advances 1/3 + 1/4 = 7/12 of distance round B. The fractions, if reduced
to a common denominator, are as 4:7, and this is equivalent to 40
(number of teeth on A): 40 + 30 (teeth on A + teeth on C.)

To leave the reader with a very clear idea we will summarize the matter
thus:--If T = number of teeth on A, _t_ = number of teeth on C, then
movement of A: movement of B:: T + _t_: T.

Here is a two-speed hub. Let us count the teeth. The chain-ring (= A)
has 64 internal teeth, and the central cog (= C) on the axle has 16
teeth. There are four cogs (= B) equally spaced, running on pins
projecting from the hub-shell between A and C. How much faster than B
does A run round C? Apply the formula:--Motion of A: motion of B:: 64 +
16: 64. That is, while A revolves once, B and the hub and the
driving-wheel will revolve only 64/80 = 4/5 of a turn. To use scientific
language, B revolves 20 per cent. slower than A.

This is the gearing we use for hill-climbing. On the level we want the
driving-wheel to turn as fast as, or faster than, the chain-ring. To
make it turn at the same rate, both A and C must revolve together. In
one well-known gear this is effected by sliding C along the spindle of
the wheel till it disengages itself from the spindle, and one end locks
with the plate which carries A. Since B is now being pulled round at the
bottom as well as the top, it cannot rotate on its own axis any longer,
and the whole train revolves _solidly_--that is, while A turns through a
circle B does the same.

To get an _increase_ of gearing, matters must be so arranged that the
drive is transmitted from the chain-wheel to B, and from A to the hub.
While B describes a circle, A and the driving-wheel turn through a
circle and a part of a circle--that is, the driving-wheel revolves
faster than the hub. Given the same number of teeth as before, the
proportional rates will be A = 80, B = 64, so that the gear _rises_ 25
per cent.

By means of proper mechanism the power is transmitted in a three-speed
gear either (1) from chain-wheel to A, A to B, B to wheel = _low_ gear;
or (2) from chain-wheel to A and C simultaneously = solid, normal, or
_middle_ gear; or (3) from chain-wheel to B, B to A, A to wheel = _high_
gear. In two-speed gears either 1 or 3 is omitted.

       *       *       *       *       *

AGRICULTURAL MACHINES.


THE THRESHING-MACHINE.

Bread would not be so cheap as it is were the flail still the only means
of separating the grain from the straw. What the cream separator has
done for the dairy industry (p. 384), the threshing-machine has done for
agriculture. A page or two ought therefore to be spared for this useful
invention.

[Illustration: FIG. 226.--Section of a threshing machine.]

In Fig. 226 a very complete fore-and-aft section of the machine is
given. After the bands of the sheaves have been cut, the latter are fed
into the mouth of the _drum_ A by the feeder, who stands in the
feeding-box on the top of the machine. The drum revolves at a very high
velocity, and is fitted with fluted beaters which act against a steel
concave, or breastwork, B, the grain being threshed out of the straw in
passing between the two. The breastwork is provided with open wires,
through which most of the threshed grain, cavings (short straws), and
chaff passes on to a sloping board. The straw is flung forward on to the
shakers C, which gradually move the straw towards the open end and throw
it off. Any grain, etc., that has escaped the drum falls through the
shakers on to D, and works backwards to the _caving riddles_, or moving
sieves, E. The _main blower_, by means of a revolving fan, N, sends air
along the channel X upwards through these riddles, blowing the short
straws away to the left. The grain, husks, and dust fall through E on to
G, over the end of which they fall on to the _chaff riddle_, H. A second
column of air from the blower drives the chaff away. The heavy grain,
seeds, dust, etc., fall on to I, J, and K in turn, and are shaken until
only the grain remains to pass along L to the elevator bottom, M. An
endless band with cups attached to it scoops up the grain, carries it
aloft, and shoots it into hopper P. It then goes through the shakers Q,
R, is dusted by the _back end blower_, S, and slides down T into the
open end of the rotary screen-drum U, which is mounted on the slope, so
that as it turns the grain travels gradually along it. The first half of
the screen has wires set closely together. All the small grain that
falls through this, called "thirds," passes into a hopper, and is
collected in a sack attached to the hopper mouth. The "seconds" fall
through the second half of the drum, more widely spaced, into their
sack; and the "firsts" fall out of the end and through a third spout.


MOWING-MACHINES.

[Illustration: FIG. 227.]

The ordinary _lawn--mower_ employs a revolving reel, built up of
spirally-arranged knives, the edges of which pass very close to a sharp
plate projecting from the frame of the mower. Each blade, as it turns,
works along the plate, giving a shearing cut to any grass that may be
caught between the two cutting edges. The action is that of a pair of
scissors (Fig. 227), one blade representing the fixed, the other the
moving knife. If you place a cylinder of wood in the scissors it will be
driven forward by the closing of the blades, and be marked by them as
it passes along the edges. The same thing happens with grass, which is
so soft that it is cut right through.

HAY-CUTTER.

The _hay-cutter_ is another adaptation of the same principle. A
cutter-bar is pulled rapidly backwards and forwards in a frame which
runs a few inches above the ground by a crank driven by the wheels
through gearing. To the front edge of the bar are attached by one side a
number of triangular knives. The frame carries an equal number of spikes
pointing forward horizontally. Through slots in these the cutter-bar
works, and its knives give a drawing cut to grass caught between them
and the sides of the spikes.

       *       *       *       *       *

SOME NATURAL PHENOMENA.


WHY SUN-HEAT VARIES IN INTENSITY.

The more squarely parallel heat-rays strike a surface the greater will
be the number that can affect that surface. This is evident from Figs.
228, 229, where A B is an equal distance in both cases. The nearer the
sun is to the horizon, the more obliquely do its rays strike the earth.
Hence midday is necessarily warmer than the evening, and the tropics,
where the sun stands overhead, are hotter than the temperate zones,
where, even in summer at midday, the rays fall more or less on the
slant.

[Illustration: FIG. 228.]

[Illustration: FIG. 229.]

The atmospheric envelope which encompasses the earth tends to increase
the effect of obliquity, since a slanting ray has to travel further
through it and is robbed of more heat than a vertical ray.


THE TIDES.

All bodies have an attraction for one another. The earth attracts the
moon, and the moon attracts the earth. Now, though the effect of this
attraction is not visible as regards the solid part of the globe, it is
strongly manifested by the water which covers a large portion of the
earth's surface. The moon attracts the water most powerfully at two
points, that nearest to it and that furthest away from it; as shown on
an exaggerated scale in Fig. 230. Since the earth and the water revolve
as one mass daily on their axis, every point on the circumference would
be daily nearest to and furthest from the moon at regular intervals, and
wherever there is ocean there would be two tides in that period, were
the moon stationary as regards the earth. (It should be clearly
understood that the tides are not great currents, but mere thickenings
of the watery envelope. The inrush of the tide is due to the temporary
rise of level.)

[Illustration: FIG. 230.]

[Illustration: FIG. 231.]


WHY HIGH TIDE VARIES DAILY.

The moon travels round the earth once in twenty-eight days. In Fig. 231
the point _a_ is nearest the moon at, say, twelve noon. At the end of
twenty-four hours it will have arrived at the same position by the
compass, but yet not be nearest to the moon, which has in that period
moved on 1/28th of a revolution round the earth.[43] Consequently high
tide will not occur till _a_ has reached position _b_ and overtaken the
moon, as it were, which takes about an hour on the average. This
explains why high tide occurs at intervals of more than twelve hours.

[Illustration: FIG. 232.--Relative positions of sun, moon, and earth at
"spring" tides.]

[Illustration: FIG. 233.--Relative positions of sun, moon, and earth at
"neap" tides.]


NEAP TIDES AND SPRING TIDES.

The sun, as well as the moon, attracts the ocean, but with less power,
owing to its being so much further away. At certain periods of the
month, sun, earth, and moon are all in line. Sun and moon then pull
together, and we get the highest, or _spring_ tides (Fig. 232). When sun
and moon pull at right angles to one another--namely, at the first and
third quarters--the excrescence caused by the moon is flattened (Fig.
233), and we get the lowest, or _neap_ tides.

[39] In both Figs. 207 and 208 the degree of expansion is very greatly
exaggerated.

[40] As the sun passes the meridian (twelve o'clock, noon) the
chronometer's reading is taken, and the longitude, or distance east or
west of Greenwich, is reckoned by the difference in time between local
noon and that of the chronometer.

[41] For much of the information given here about clocks and watches the
author is indebted to "The History of Watches," by Mr. J.F. Kendal.

[42] We shall here notice only those gears which are included in the hub
of the driving-wheel.

[43] The original position of the moon is indicated by the dotted
circle.




INDEX.

NOTE.--Figures in italics signify that an illustration of the thing
referred to appears on the page.


  Aberration, spherical, of lens, 243.

  Acoustics, 294.

  Achromatic lens, 243.

  Action carriage of piano, 283.

  Advancing the spark, 102.

  Air-gun, _342_.

  Air-pump for cycle tyres, _340_;
    for Westinghouse brake, 199.

  Alternating currents, 164;
    dynamo, 164.

  Amperage, 125.

  Angle of advance, 57, 58;
    incidence, 268;
    reflection, 268.

  Aorta, 360.

  Arc lamp, 182.

  Archimedes, 412.

  Armature, 162.

  Arteries, 358.

  Arterial blood, 359.

  Atmospheric pressure, 350.

  Auditory nerve, 272.

  Automatic brakes, 188;
    signalling, 228;
    stoker, 399.


  Backfall, 298.

  Balance-wheel, 419.

  Ball cock, 366, _367_.

  Balloon, fire, 323;
    gas, 347.

  Barometer, aneroid, 328, _329_;
    and weather, 331;
    Fortin's, _326_;
    meaning of, 325;
    simple, _328_;
    wheel, _327_.

  Beau de Rochas, 89.

  Bell, diving, _332_;
    electric, 119, _120_.

  Bellows of organ, 303.

  Bioscope, 266.

  Blades, turbine, _81_, 83.

  Block system, 201, 212.

  Blood, arterial, 359;
    circulation of, _356_, _357_, 360;
    venous, 359.

  Blower-plate, 393, _394_.

  Boat, sails of, 346.

  Boiler, Babcock and Wilcox, _21_, 22;
    explosions, 34, 391;
    fire-tube, 21;
    fittings, 31;
    Lancashire, 25, _26_;
    locomotive, _20_, 23;
    multitubular, 21;
    principle of, 15;
    stored energy in, 32;
    vertical, _25_;
    water supply to, 39;
    water-tube, 21.

  Brakes, hydraulic, 188;
    motor car, 110;
    railway, 187;
    vacuum, 189, _190_, _191_;
    Westinghouse, 194, _195_, _197_.

  Bramah, 363, 437.

  Breezes, land and sea, 324.

  Brushes of dynamo, 161, _172_.

  Bunsen burner, 409.

  Burning-glass, 232.


  Camera, the, 233;
    pinhole, _234_, _235_.

  Canals, semicircular, 273.

  Capillary attraction, 392;
    veins, 358.

  Carbon dioxide, 27, 359;
    monoxide, 27.

  Carburetter, 98, _99_.

  Cardan shaft, 93.

  _Carmania_, the, 83.

  Centrifugal force, 382.

  Change-speed gear, 105, 442.

  Chassis of motor car, 92.

  Circulation of water in a boiler, _17_, _18_, _19_;
    of water in a motor car, 95, _97_.

  Clarionet, 308.

  Clock, first weight-driven, 412;
    water, 410.

  Clutch of motor car, 105.

  Coal, as fuel, 15;
    gas, 394;
    gas making, 394;
    gas plant, _396_;
    gas, purification of, 397.

  Cochlea, 273.

  Coherer, 140.

  Coil, Ruhmkorff, 121.

  Coke, 395.

  Combinations in Chubb lock, 436;
    Yale lock, 436.

  Combustion, 26, 393;
    perfect, 28.

  Compensating gear, 107, _108_.

  Compound engines, 59;
    arrangement of, 61;
    invention of, 59.

  Compound locomotives, 62.

  Compound microscope, 261.

  Condenser, marine, 71, _72_;
    of Ruhmkorff coil, 123.

  Conduit, 176.

  Convex lens, image cast by, _236_.

  Conjugate foci, 262.

  Cornet, 308.

  Corti, rods of, 274.

  Coxwell, 348.

  Cream separator, 381, _383_.

  Current, reversal of electric, _130_, 131;
    transformation of, 124.

  Cushioning of steam, 55.

  Cycle, gearing of, 439.

  Cylinder, hydraulic press, _363_;
    steam, _49_.


  Danes, 382.

  Dead point, 47.

  De Brouwer stoker, 401.

  Detector in Chubb lock, 435.

  Diving-bell, _332_;
    simple, _333_, _334_.

  Diving-dress, 335.

  Direction of current in dynamo circuit, 163.

  Diver's feats, 338;
    helmet, _336_;
    lamp, _338_.

  Donkey-engines, 68.

  Doorstop, self-closing, 344.

  Double-cylinder engines, 47.

  Draught, forced, 28, _29_;
    induced, 29.

  Drum and fusee, _414_.

  Durability of motor-car engine, 96.

  D-valve, 67.

  Dynamo, alternating, 164, 174;
    brushes, _172_;
    compound, 174;
    continuous-current, 165;
    multipolar, 169;
    series wound, _173_;
    shunt wound, _173_;
    simple, 161, _162_.


  Ear, the, _271_, _273_;
    a good, 274, 307;
    sensitiveness of, 275.

  Eccentric, _52_, 53;
    setting of, 53.

  Edison, Thomas, 310.

  Edison-Bell phonograph, 310.

  Electricity, current, 115;
    forms of, 113;
    nature of, 112;
    static, 114.

  Electric bell, 119, _120_;
    signalling, 225;
    slot, 226.

  Electroplating, 185, _186_.

  Electro-magnets, 117.

  Endolymph, 272.

  Engines, compound, 59;
    donkey, 68;
    double-cylinder, 47;
    internal-combustion, 87, 95;
    reciprocating, 44.

  Escapement of timepieces, 416;
    cylinder, _420_;
    lever, 421, _422_.

  Ether, 270.

  Eustachian tube, 276.

  Eye, human, 246, _247_;
    self-accommodation of, 248.

  Expansive working of steam, 56.


  Faraday, Michael, 159.

  Field, magnetic, 159;
    magnets, 171;
    ring, 174.

  Filters, 374;
    Maignen, _373_;
    Berkefeld, 374.

  Filtration beds, 372.

  Flute, 308.

  Flying-machines, 348.

  Fly-wheel, use of, 48.

  Focus, meaning of, 237;
    principal, 238.

  Foci, conjugate, 262.

  Force, lines of, 116.

  Forces, component, 345.

  Free wheel, _440_.

  Furring-up of pipes, 391.

  Fusee, drum and, 414.


  Galileo, 259, 325, 416.

  Galilean telescope, _259_.

  Gas, coal, 394;
    governor, 402;
    meter, 405;
    traps, 374;
    works, 394.

  Gasometer, 397;
    largest, _398_, 399.

  Gauge, steam, 36, _38_;
    water, 35, _36_.

  Gear, compensating, 107, _108_.

  Gear-box of motor car, 105.

  Gearing of cycle, 439.

  Glaisher, 348.

  Gland, 50, 363.

  Glass, flint and crown, 242.

  Going-barrel for watches, 415.

  Gooch reversing gear, 65.

  Governors, speed, 67;
    of motor car, 103, _104_.

  Graham, 418.

  Gramophone, 317;
    records, 319, 321;
    reproducer, _318_.


  Hairspring, 412.

  Hay-cutter, 451.

  Heart, the, 355;
    disease, 361;
    rate of pulsation of, 361;
    size of, 357.

  Heat of sun, 451.

  Hele, Peter, 412.

  Helmet, diver's, _336_.

  Helmholtz, 274, 308.

  Hero of Alexandria, 74.

  Herschel, 261.

  Hertz, Dr., 138.

  Hertzian waves, 138.

  Hot-water supply, 386.

  Hour-hand train in timepieces, _429_.

  Household water supply, 364.

  Hughes type-printer, 134.

  Hydraulic press, 361, _362_.

  Hydro, 385.


  Ignition of charge in motor-car cylinder, 100, _101_.

  Image and object, relative positions of, 239;
    distortion of, 245.

  Incandescent gas mantle, 407;
    electric lamp, 179.

  Incus, 272.

  Index mechanism of water-meter, 37.

  Indicator of electric bell, 119.

  Induction coil, 121;
    uses of, 125.

  Injector, 39;
    Giffard's, _41_;
    principle of, 40;
    self-starting, 42.

  Interlocking of signals, 204, 222.

  Internal-combustion engine, 87.

  Iris of eye, 249;
    stop, 249.


  Kelvin, Lord, 158.

  Keyless winding mechanism, 425, _426_, 428.

  Kite, 345.


  Lamp, arc, 182;
    how it works, 392;
    incandescent, 179;
    manufacture of incandescent lamps, 180.

  Lap of slide-valve, _57_, 59.

  Larynx, 306.

  Laxey wheel, _380_, 381.

  Leads, 208.

  Lenses, 231;
    correction of for colour, 240, _241_;
    focus of, 236;
    rectilinear, _245_;
    spherical aberration in, 243.

  Levers, signal, colours of, 208.

  Limit of error in cylinder, 52.

  Light, electric, 179;
    nature of, 230;
    propagation of, 231.

  Li Hung Chang, 157.

  Lindsay, James Bowman, 145.

  Lines of force, 116, 162.

  "Linking up," 65.

  Locks, 430;
    Barron, 433;
    Bramah, 437;
    Chubb, 433, 434;
    Hobbs, 437;
    simplest, _431_;
    tumbler, _432_;
    Yale, _436_.

  Locking gear for signals, 205.

  Locomotive, electric, 178;
    advantages of, 179.

  Lungs, 359.


  Magic-lantern, 263, _264_.

  Magnet, 115;
    permanent, 115, 116;
    temporary, 115.

  Magnetism, 115.

  Magnetic needle, influence of current on, 129.

  Mainspring, invention of, 412.

  Malleus, 272.

  Marconi, 140, 146.

  Marine chronometers, 415;
    delicacy of, 425.

  Marine speed governor, 71.

  Marine turbine, advantages of, 84.

  Maudslay, Henry, 363.

  Maxim, Sir Hiram, 348.

  Micrometer free wheel, 441.

  Micro-photography, 265.

  Microscope, 254;
    compound, 261, _263_;
    in telescope, 257;
    simple, _254_.

  Mineral oil, 392.

  Mirror, parabolic, 261, _262_;
    plane, _267_.

  Morse, 132, 145;
    code, 128;
    inker, 142;
    sounder, 132.

  Motor car, the, 92;
    electric, 177.

  Mouth, 307.

  Mowing-machines, 450.

  Musical sounds, 277.


  Nerve, auditory, 272;
    optic, 246.

  Nodes on a string, 285;
    column of air, 291.

  Note, fundamental, 285;
    quality of, 285.

  Niagara Falls, power station at, 174.


  Organ, the, 294, _300_;
    bellows, 303;
    console, 305;
    echo, solo, swell, great, and choir, 301;
    electric and pneumatic, 305;
    largest in the world, 306;
    pedals, 298;
    pipes, 295;
    pipes, arrangement of, 295;
    sound-board, _296_;
    wind-chest, 297.

  Otto cycle, 91.

  Overtones, 285.


  Pallets of organ, 297.

  Parallel arrangement of electric lamps, 184.

  Paris, siege of, 265.

  Pedals of organ, 298.

  Pelton wheel, _377_.

  Pendulum, 412;
    compensating, 418, _419_.

  Perilymph, 272.

  Perry, Professor, 16.

  Petrol, 98.

  Phonograph, 310;
    governor, _311_;
    recorder, 312, _313_;
    records, making of, 319;
    reproducer, 315;
    tracings on record of, _317_.

  Pianoforte, 277;
    sounding-board, 280;
    striking mechanism, 281;
    strings, 281.

  Piccolo, 308.

  Pipes, closed, 289;
    flue, 301;
    open, 292;
    organ, 295;
    reed, 301, _302_;
    tuning, 302.

  Piston valve, 67.

  Pneumatic tyres, 341.

  Poldhu, signalling station at, 138.

  Points, railway, 208, _210_;
    and signals in combination, 211.

  Poles of a magnet, 115.

  Popoff, Professor A., 138, 145.

  Power, transmission of, 175.

  Preece, Sir William, 145.

  Primary winding of induction coil, 122.

  Pump, air, 340;
    bucket, 352, _353_;
    force, 354;
    most marvellous, 355;
    Westinghouse air, 199.


  Railway brakes, 187;
    signalling, 200.

  Rays, converging and diverging, _256_;
    heat, concentrated by lens, _232_;
    light, 232, 235, 236, 237.

  Records, master, 319, 320.

  Reciprocation, 51.

  Reed, human, 306;
    pipes, 301, _302_.

  Reflecting telescope, 260.

  Relays, telegraphic, 133, 141.

  Retina, 247.

  Retorts, 395.

  Reversing gear, 62;
    Allan, 65;
    Gooch, 65;
    radial, 66.

  Rocking bar mechanism for watches, 425.

  Rods of Corti, 274.

  Ruhmkorff coil, 121, _122_.


  Safety-valve, 32, _33_, 391.

  Sand-glasses, 411.

  Scissors, action of, _450_.

  Secondary winding of induction coil, 122.

  Series arrangement of electric lamps, 183.

  Series winding of dynamo, _173_.

  Shunt wound dynamo, _173_.

  Sight, long and short, 250.

  Signalling, automatic, 228;
    electric, 225;
    pneumatic, 225;
    power, 225.

  Signal levers, _206_.

  Signals, interlocking of, 204;
    position of, 202;
    railway, 200;
    single line, 215.

  Silencer on motor cars, 109.

  Siphon, _351_.

  Slide-valve, 49, 50, 51;
    setting of, 53.

  Sliders, 297.

  Sound, nature of, 270;
    board of organ, 296;
    board of piano, 280.

  Spagnoletti disc instrument, 212.

  Sparking-plug, _102_.

  Spectacles, use of, 249.

  Spectrum, colours of, 230.

  Speed governors, 67, _68_, _69_;
    Hartwell, 70;
    marine, 71.

  Speed of motor cars, 110.

  Spot, blind, in eye, 251;
    yellow, in eye, 251.

  Spring balance for watches, 419;
    compensating, 423, _424_.

  Stapes, 272.

  Steam, what it is, 13;
    energy of, 14;
    engines, 44;
    engines, reciprocating, _45_;
    expansive working of, 59, 81;
    gauge, 36;
    gauge, principle of, 37;
    turbine, 74;
    turbine, De Laval, 76, _77_;
    turbine, Hero's, 74;
    turbine, Parsons, 79, _80_;
    volume of, as compared with water, 15.

  Stephenson, George, 63, 375.

  Stop, in lens, 244;
    iris, 249;
    use of, 244.

  Sun-dial of Ahaz, 410.

  Syntonic transmission of wireless messages, 143.


  Talking-machines, 310.

  Tapper in wireless telegraphy receiver, 141.

  Tappet arm, 205.

  Telegraph, electric, 127;
    insulator, _133_;
    needle, _128_;
    recording, 133;
    sounder, 132.

  Telegraphy, high-speed, 135;
    wireless, 137.

  Telephone, 147;
    Bell, _148_;
    circuit, double-line, 155;
    circuit, general arrangement, _152_, 153;
    exchange, _154_, 155.

  Telephony, submarine, 157.

  Telescope, 257;
    Galilean, _259_;
    prismatic, _260_;
    reflecting, 260;
    terrestrial, _259_.

  Threshing-machine, 447, _448_.

  Thurston, Professor, 31.

  Tides, 452;
    high, 453;
    neap and spring, 455.

  Timbre, 285.

  Tompion, Thomas, 412.

  Torricelli, 325.

  Trachea, 306.

  Train staff signalling, 216;
    single, 216;
    and ticket, 217;
    electric, 218.

  Transformation of current, 124, 176.

  Transmission of power, 174, _175_.

  Transmitter, Edison telephone, 150;
    granular carbon, 150, _151_.

  Triple-valve, 196.

  Trolley arm, 176.

  Turbines, steam, 74.

  _Turbinia_, the, 79.

  Tympanum, 137, 271, 272.


  Universal joint, 93.


  Vacuum brake, 189, _190_, _191_.

  Vacuum chamber of aneroid barometer, _330_.

  Valve, piston, 67;
    safety, 32;
    of internal-combustion engine, 89.

  Valves of the heart, 357.

  Veins, 358;
    capillary, 358;
    pulmonary, 361.

  Ventral segments, 291.

  Ventricles, 357.

  Vibration of columns of air, 288, 289;
    of rods, 287;
    of strings, 278;
    of strings, conditions regulating, 278.

  _Viper_, the, 86.

  Virag, Pollak--high-speed telegraphy, 136.

  Vitreous humour, 246.

  Voltage, 121, 161.

  Vowel sounds, 308.


  Wasborough, Matthew, 51.

  Watches, first, 412.

  Water cock, _365_;
    engines, 375;
    gauge, 35, _36_;
    jacket, 19, 95;
    meter, _368_;
    supply, 371;
    turbines, 174, 376;
    wheels, 375.

  Watt, James, 51, 69, 375.

  Welsbach incandescent mantle, 407.

  Westinghouse air-brake, 194, _195_, _197_;
    George, 194.

  Wheatstone needle instrument, 128, 131;
    automatic transmitter, 135.

  Wind, why it blows, 323;
    action of on kites, 345;
    on sails, 346.

  Windmills, 375.

  Window, oval, in ear, 272;
    round, in ear, 272.

  Wireless telegraphy, 137;
    advance of, 145;
    receiver, 140, 141;
    syntonic, 143;
    transmitter, 138, _139_.


  Yale lock, _436_, _437_.

  Yellow spot, in eye, 251.


  Zech, Jacob, 414.

  Zeiss field-glasses, 260.


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END OF THE BOOK
=====================================================================
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NEW BOOK





The Project Gutenberg eBook of The book of wonders
    
This ebook is for the use of anyone anywhere in the United States and
most other parts of the world at no cost and with almost no restrictions
whatsoever. You may copy it, give it away or re-use it under the terms
of the Project Gutenberg License included with this ebook or online
at www.gutenberg.org. If you are not located in the United States,
you will have to check the laws of the country where you are located
before using this eBook.

Title: The book of wonders
        gives plain and simple answers to the thousands of everyday questions that are asked and which all should be able to, but cannot answer...

Editor: Rudolph J. Bodmer

Release date: April 24, 2025 [eBook #75948]

Language: English

Original publication: New York: Presbrey Syndicate, Inc, 1914

Credits: Charlene Taylor, Harry Lamé and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive/American Libraries.)


*** START OF THE PROJECT GUTENBERG EBOOK THE BOOK OF WONDERS ***



  Transcriber’s Notes

  Words, letters and phrases printed in boldface or italics in the
  source document have been transcribed between =equal signs= and
  _underscores_ respectively. Small capitals have been transcribed
  as ALL CAPITALS. Phrases between ~tildes~ represent side notes. ^o
  stands for a superscript o.

  More Transcriber’s Notes may be found at the end of this text.




  THE
  BOOK OF WONDERS


[Illustration: HOW MAN BURROWS UNDER THE WATER

This is a picture of a section of one of the world’s greatest tunnels,
showing how man has learned to construct great tubes of steel beneath
the surface of the water and land, in which to run the swiftly moving
trains which carry him rapidly from place to place.]




  THE
  BOOK OF WONDERS

  GIVES PLAIN AND SIMPLE ANSWERS TO THE
  THOUSANDS OF EVERYDAY QUESTIONS
  THAT ARE ASKED AND WHICH ALL SHOULD
  BE ABLE TO, BUT CANNOT ANSWER

  FULLY ILLUSTRATED WITH HUNDREDS OF EDUCATIONAL PICTURES
  WHICH STIMULATE THE MIND AND GIVE A
  BIRD’S EYE VIEW OF THE

  WONDERS OF NATURE
  and the
  WONDERS PRODUCED BY MAN

  Edited and Arranged by
  RUDOLPH J. BODMER


  Fully Indexed

  1915
  PRESBREY SYNDICATE, INC.
  456 Fourth Avenue
  NEW YORK




  Copyright, 1914
  BY
  PRESBREY SYNDICATE, Inc.




Introduction


No truly great book needs an explanation of its aim and purpose. A
great book just grows, as has this Book of Wonders.

It began with the attempt of a father to answer the natural questions
of the active mind of a growing boy. It developed into a nightly search
for plain, understandable answers to such questions as “What makes
it night?” “Where does the wind begin?” “Why is the sky blue?” “Why
does it hurt when I cut my finger?” “Why doesn’t it hurt when I cut my
hair?” “Why does wood float?” “Why does iron sink?” “Why doesn’t an
iron ship sink?” on through the maze of thousands of puzzling questions
which occur to the child’s mind. It has grown until the answers to
the mere questions cover practically the entire range of every-day
knowledge, and has been arranged in such a form that any child may now
find the answer to his own inquiries.

As the mind of the child matures, the questions naturally drift toward
the things which the genius of man has provided for his comfort and
pleasure. We have become so accustomed to the use and benefits of these
wonders produced by man that we generally leave out of our books the
stories of our great industries, and yet the mind of the child wonders
and inquires about them. We have so long worn clothes made of wool or
cotton, that we have forgotten the wonder there is in making a bolt
of cloth. Every industry has a fascinating story equal to that of the
silkworm, which moves its head sixty-five times a minute while spinning
his thousand yards of silk.

Can you tell What happens when we telephone? How a telegram gets
there? What makes an automobile go? How man learned to tell time? How
a moving-picture is made? How a camera takes a picture? How rope is
made? How the light gets into the electric bulb? How glass is made?
How the music gets into the piano? and hundreds of others that embrace
the captivating tales of how man has made use of the wonders of nature
and turned them to his advantage and comfort? The Book of Wonders does
this with illuminating pictures which stimulate the mind and give a
bird’s-eye view of each subject step by step.

Where shall such a book begin? Shall it begin with the Story of How
Man Learned to Light a Fire--he could not cook his food, see at night,
or keep warm without a fire; or should it begin with How Man Learned to
Shoot--he could not protect himself against the beasts of the forest,
and, therefore, could not move about, till the soil or obtain food to
cook until he knew how to shoot or destroy.

What was the vital thing for man to know before he could really become
civilized? Some means, of course, by which the things he learned--the
knowledge he had acquired--could be handed down to those who came after
him so that they might go on with the intelligence handed down to them.
This required some means of recording his knowledge. Man had to learn
to write. Without writing there could be no Book of Wonders, and the
book, then, begins naturally with the Story of Mow Man Learned to Write.

  THE EDITOR.

[Illustration: WRITING BY MEXICAN INDIANS THOUGHT TO BE MORE THAN TEN
THOUSAND YEARS OLD.]




How Man Learned to Write


It is a long time between the day of the cave-dwellers, with their
instruments of chipped stone, and the present day of the pen. Yet wide
apart as are these points of time, the trend of development can with
but few obstacles be traced.

The story of the pen is a natural sequence of ideas between the first
piece of rock scratched upon rock by prehistoric man, and the bit of
metal which now so smoothly records our thoughts.

There was a time in the unwritten history of man when necessity
prompted the invention of weapons, and the minds of these primitive men
were concentrated upon this point. But the arts of war did not take up
their entire time; some time must have been given to other pursuits.
As the mind developed, and as an aid to memory, we find them carving,
engraving, incising upon the rocks their hieroglyphics, which took the
form of figures of men, habitations, weapons, and the animals of their
period.

[Illustration: THE STYLUS]


How Did Writing First Come About?

An apparently difficult question to answer, since without writing there
can be no record of its origin, and without records no facts; yet the
deduction is so clear that the answer is simple. Somewhere far, far
back in the dawn of the world, back in the beginning of human history,
in the epoch which we have now named the Quaternary Period, man lived
in a dense wilderness surrounded by the wildest and most ferocious
beasts. His home was a cave, exposed to the dangers incidental to that
time and his surroundings, and he was of necessity compelled to look
about for means of defense. With this idea in mind, he found that by
striking one stone against another he knocked off chips, which chips
could be used as arrow-heads, spears and axes. Following along these
lines he discovered that by rubbing one of these chips against another
there was left a mark, which was the first imitation of writing; that
the sharper the edge of the chip, the deeper was the scratch, and
consequently the more distinct the mark.

[Illustration: EARLIEST WAYS OF WRITING

THE FIRST IMITATION OF WRITING]

Next it was discovered that certain stones, such as flint, serpentine
and chalcedony, marked more readily than others; that the elongated
chip was handled with more facility; that by rubbing one stone against
another the finest possible points and edges might be obtained. Thus in
the Age of Stone was the long, tapering instrument of stone, the first
pen, the Stylus, originated.

Then came the time, known as the Bronze Age, when men learned to
hammer metal into shapes, and metal having many advantages over stone,
the stylus of stone gave way to one of iron. So we find that in the
time of the Egyptians, about fourteen or fifteen centuries B.C., an
iron stylus was in use for marking on soapstone, limestone and waxed
surfaces. An improvement in this metal stylus was that the blunt end
was convex and smooth, the purpose of which was to erase and smooth
over irregularities. In some cases it was pointed with diamonds, which
gave it greater cutting properties. The iron stylus was also used by
the Egyptians of that period, as well as in later times, with a mallet,
after the manner of the modern chisel (which indeed it resembled) for
cutting out inscriptions on their monuments.

[Illustration: THE BRUSH]

~WRITING FLUIDS HELPED DEVELOPMENT~

In course of time a marking fluid was discovered, and this made
necessary a writing instrument which could spread characters on
parchment, tree-bark, etc. Thus it was found that by putting together
a small bunch of hairs, arranging them in the shape of an acute cone,
and fastening them together in some manner, an instrument could be
made which would carry fluid in its path, and thus make a mark of the
desired shape. The hair best adapted for the purpose was found to be
camel’s hair, while that of the badger and sable was also used. A tube
cut from a stalk of grass answered for a holder. The hairs were held
together by a piece of thread which was then drawn through the tube,
thus making the first writing instrument to be used in conjunction with
ink, the Brush.

[Illustration: HOW THE CHINESE IMPROVED METHODS]

Just when the Brush came into existence is not definitely known, but
with this instrument the great Chinese philosopher Confucius wrote his
marvelous philosophy. The Brush as a writing instrument is generally
associated with the Chinese, because the Chinese use this instrument
even to the present day, it being especially adapted to their letters
and mode of writing. We have now a pen (brush), as well as an ink, but
the material upon which the people of that age wrote, in lieu of paper,
was still very crude, parchment and tree-bark being most commonly used.

[Illustration: THE QUILL]

~THE EARLIEST FORMS OF PAPER~

Just as the discovery of an ink wrought a change from the Stylus to
the Brush, so the advent of papyrus, a paper made from the papyrus
plant, which was much finer and more economical than parchment, brought
with it a pen better adapted for this material. It was found that
the Reed, or Calamo, as it was called, which grew on the marshes on
the shores of Egypt, Armenia and the Persian Gulf, if cut into short
lengths and trimmed down to a point, made an admirable pen for this
newly discovered paper. This was the true ancient representative and
precursor of the modern pen. The use of the Reed can be traced to a
remote antiquity among the civilized nations of the East, where Reeds
are in use now as instruments for writing.

[Illustration: HOW THE MONKS DID THEIR WRITING]

The introduction of a finer paper rendered necessary a finer instrument
of writing, and the quill of the goose, swan, and, for very fine
writing, of the crow, was found to be well adapted. Immense flocks of
geese were raised, chiefly for their quills. The earliest specific
allusion to the quill occurs in the writings of St. Isadore de Seville,
seventh century, although it is believed to have been in use at an
earlier period. The quill was used for many centuries. Most of the
writing during its reign was done in the monasteries by the monks, and
in the eighteenth century, when quill-making became quite an art,
every monk and every teacher was expected to be proficient in the art
of making a pen from a quill. The preliminary process of preparing the
quills was first to sort them according to their quality, dry in the
hot sand, then clean them of the outer skin, and harden by dipping in
a boiling solution of alum and diluted nitric acid. During the last
century many efforts were made to improve the quill, its great defect
being speedy injury from use. Ruby points were fitted to the nib, but
this was found impracticable on account of the delicacy of the work.
Joseph Bramah devised, in 1809, a machine for cutting the quill into
separate nibs for use in holders, thus making several pens from one
quill and anticipating the form of the modern pen.

[Illustration: THE STEEL TUBE PEN]

[Illustration: THE FIRST STEEL PEN]

The quill held sway as writing instrument for many years, and with
it the greatest masterpieces in literature have been written. Many
attempts, however, had been made to supersede the quill by a pen not so
easily injured by use, but it was not until about 1780 that, after much
experimenting and numerous failures, Mr. Samuel Harrison introduced the
first metallic pen.

~THE INVENTION OF THE PEN~

This pen was made as follows:

A sheet of steel was rolled in the form of a tube. One end was cut and
trimmed to a point after the manner of the quill, the seam where both
edges of the tube met forming the slit of the pen. This was soon after
improved upon by cutting a rough blank out of a thin sheet of steel,
which blank was filed into form about the nib, rounded, and with a
sharp chisel marked inside where the slit was to be in the finished
pen. After tempering, the nib was ground and shaped to a point
suitable for fine or broad writing, as required.

[Illustration: THE MODERN STEEL PEN]

[Illustration: THE MODERN WRITING PEN]

Once started, the steel pen made rapid strides in improvement. Mr.
James Perry, in 1824, started in England the manufacture of pens on a
large scale, and to him as well as Gillott is due the many improvements
which followed.

Perry was the first to manufacture “slip” steel pens, up to this time
the pen and holder being one piece.

    “In times of yore, when each man cut his quill
    With little Perryian skill;
    What horrid, awkward, bungling tools of trade
    Appeared the writing instruments, home made!”

~THE MODERN WAY OF WRITING~

The steel pen of the present day has reached the pinnacle of
perfection, and the method of manufacture of this little but mighty
instrument of writing, though of extreme interest, is practically
unknown by the general public. To explain in detail the development
from the rough steel to the finished pen would needs make a book
in itself. And as it has been our intention to dwell, not upon the
manufacture of the pen, but to trace its history and development from
its most crude form, the Stylus, to the perfect and smooth-writing
steel pen of to-day, we will close our story with the well-worn epigram
of old, grim Cardinal Richelieu:

    “Beneath the rule of men entirely great,
    The Pen is mightier than the Sword!”


How a Steel Pen is Made

  In the picture on the following page, we see the various processes
  required in making a steel pen, together with a description of each
  process:

[Illustration: HOW A STEEL PEN IS MADE

  N^o. 1. ROLLED STEEL.

  N^o. 2. SCRAP.

  N^o. 3. BLANKS.

  N^o. 4. MARKING.

  N^o. 5. PIERCING.

  N^o. 6. ANNEALING.

  N^o. 7. RAISING.

  N^o. 8. HARDENING.

  N^o. 9. TEMPERING.

  N^o. 10. SCOURING.

  N^o. 11. GRINDING.

  N^o. 12. SLITTING.

  N^o. 13. No. 1. COLLEGE PEN No. 5. SCHOOL PEN.
  (FINISHED PENS.)
  COLORING AND VARNISHING.

  The pictures herewith printed are by the courtesy of the Spencerian
  Pen Company

  _Raw Material._--The sheet steel is cut into strips of a convenient
  length and width, and then rolled cold to the exact gauge necessary,
  according to the pen to be manufactured.

  _Cutting the Blank._--This is a mechanical operation, and is effected
  with the aid of a screw press, in which a pair of tools corresponding
  with the shape of the pen has been fixed. On pulling a lever the
  screw descends, driving the punch into the bed, which cuts a blank
  with a scissors-like action, from the strip of steel.

  _Marking the Name._--This is done by means of a punch fixed in
  the hammer of a stamp, worked by the foot. The blanks are rapidly
  introduced between guides fixed on the bed of the stamp, and as
  soon as the hammer has fallen the blank is thrown out and a new one
  introduced.

  _Piercing._--The tools for this operation are of a delicate
  character. The blanks are fed by hand, as above explained, and the
  hole punched by a screw press. This is a most important process; the
  pierce hole and slide slits determine the elasticity and regulate the
  flow of the ink on the pen.

  _Annealing or Softening._--The blanks are still moderately hard and
  before raising, it is necessary to soften them by heating to a dull
  red, and allowing them to gradually cool.

  _Raising._--The operator places one of the soft blanks on a die to
  which guides are affixed to keep it in position; then by moving the
  handle of the press, the screw descends, forcing a die which rounds
  the blank into the form of a pen.

  _Hardening._--The pen is now too soft, and is hardened by heating and
  the immersing in oil while hot, after which it is thoroughly cleansed
  from all grease.

  _Tempering._--The pens are now hard but very brittle, and in order
  to correct this defect they are placed in an iron cylinder, and kept
  revolving over a gas or charcoal fire until they acquire a proper
  temper.

  _Scouring._--After soaking in diluted sulphuric acid, the pens are
  placed in iron cylinders containing fine stone and water, or fine
  sand, and revolved for several hours. When taken from these cylinders
  they are bright and smooth.

  _Grinding._--This is a process performed by hand on a “bob,” or
  wooden wheel covered with leather and dressed with emory, revolving
  at high speed. A light touch on the emory wheel grinds off the
  surface between the pierce hole and the point, to obtain proper
  action and to assist the flow of ink.

  _Slitting._--This is a hand process performed with a press, the
  cutters being as sharp as razors. The pen is placed in position by
  means of guides, and must be cut with utmost precision from the
  pierce hole to the point, the point must be divided exactly in the
  middle, the least variation making the pen defective.

  _Coloring and Varnishing._--The pens having been polished to a bright
  silver color are placed in an iron cylinder and kept revolving over
  a gas or charcoal fire until the tint required is produced. They are
  then immersed in a bath of shellac varnish, and afterwards dried in
  an oven.

  _Examination._--Every steel pen passing through the factory is most
  carefully examined before being boxed, and should the least fault be
  found, it is at once rejected.]


Why Does a Pencil Write?

You can use a pencil to write with or to make marks, because the pencil
wears off if you are scratching it on a surface that is rough enough
to make it do so. Writing, you know, is only a way of making marks in
such a manner as to make them mean something. You cannot write with a
pencil on a pane of glass, because the glass is so smooth that when
you move the pencil over its surface, the pencil will not wear off. To
prove to yourself that the tip of the pencil constantly wears off when
you write, you have only to recall that when you write with it a pencil
keeps getting shorter and shorter. A slate-pencil will wear down short
by merely writing with it, but a lead-pencil must be sharpened--that
is, you must keep cutting away the wood in order to get at the lead
inside.


Why Can’t I Write on Paper With a Slate-pencil?

You cannot do so, because it takes something with a rougher surface
than paper to wear off the point of a slate-pencil. A slate is used to
write on with slate-pencils, because slate wears off the end of the
pencil easily, and also because you can rub out the writing on a slate
with water. Lead-pencils are used for writing on paper, but you must
have a rough surface on the paper to write on even with a lead-pencil.
Some kinds of papers have such a smooth surface that you cannot write
on them with a lead-pencil.


How Does a Pen Write?

Writing with a pen, however, is quite different from writing with any
kind of pencil, because in writing with ink we do not wear off the end
of the pen, but have the ink flow from the pen. For this purpose we
must have a surface that will absorb the ink from the pen, and draw
the ink down off the pen and make it flow. A slate has no power of
absorption and therefore cannot draw the ink. A piece of blotting paper
is the best kind of paper for absorbing ink, but it is too much so for
writing purposes. For writing with ink we need a comparatively hard
surfaced paper that has absorbent qualities, but not too absorbent.




How Does a Blotter Take Up the Ink of a Blot?


It is because the blotter has a very excellent ability to absorb some
liquids. The thinner the liquid the more easily the blotter will absorb
it. Ink is thin--being mostly water--the blotter is of a loose texture
and has a rough surface. This gives the blotter the ability to pick up
the ink, just as a sponge would do. A sponge has what is called the
power of capillary attraction and so has the blotter.




Where Does Chalk Come From?


Deposits of chalk are found on some shores of the sea. A piece of chalk
such as the teacher uses to illustrate something on the blackboard
at school consists of the remains of thousands of tiny creatures
that at one time lived in the sea. All of their bodies excepting the
chalk--called carbonate of lime in scientific language--has disappeared
and the chalk that was left was piled up where it fell at the bottom
of the ocean, each particle pressing against the other with the water
pressing over it all until it became almost solid. It took thousands of
years to make these chalk deposits of the thickness in which they are
found. Later on, through changes in the earth’s surface, the mountain
of chalk was raised until it stood out of the water and thus became
accessible to man and school teachers.




How Did Men Learn to Talk?


Talking and the words used came into being through the desire of men
to communicate with each other. Before words became known and used
man talked to those about him by the use of signs, gestures and other
movements of the body. Even to-day when men meet who cannot talk the
same language they will be seen trying to come to an understanding by
the use of signs and gestures and generally with fair results. The
need of more signs and gestures to express a constantly increasing
number of objects and thoughts led to the introduction of sounds or
combination of sounds made with the vocal cords to accompany certain
signs and gestures. In this way man eventually developed a very
considerable faculty for expressing himself. Sign by sign, gesture
by gesture and sound by sound language was slowly developed. A man
would be trying to explain something to another by sign or gesture
and to make it more clear would make a sound or combination of sounds
to put more expression into his efforts. Finally the other man would
understand what was meant and he would tell some one else, using the
same signs, gestures and sounds. Later on it would develop that to
express thus any certain thought, act or the name of a thing, all of
the people in the community would make this same combination of sounds,
signs and gestures to express the same thing. Finally the gestures
and signs would be dropped and it was found that people understood
perfectly what was meant when only the sound or combination of sounds
was produced. That made a word. All the other words were made in the
same way, one at a time, until we had enough words to express all the
ordinary things and the combination of words became a language. The
children learned the language by hearing their parents talk it, and
that is how men learned to talk.




How Did Shaking the Head Come to Mean “No”?


The origin of this method of indicating “No” is found in the result of
the mother’s efforts in the animal kingdom of trying to feed her young.
A mother animal would be trying to get her young to accept the food she
brought them and tried to put it in their mouths. Perhaps, however, the
young animal had had sufficient food or did not fancy the kind of food
offered. The natural thing to do under the circumstances would be to
close the mouth tight and shake the head from side to side to prevent
the mother from forcing the food into the mouth. Thus we get the closed
lips and the shaking the head from side to side to mean “No.” In other
words, that kind of a way of saying “No” came from an effort to say “I
don’t want any.”




How Did a Nod Come to Mean “Yes”?


The idea of nodding to mean “Yes” comes from the opposite of the action
which, as just described, indicates a “No.”

When the young animal was anxious to accept the offered food, it made
an effort to get at the food quickly. Hence, the pushing forward of the
head and the open mouth (always more or less opened when you nod to
indicate “Yes”) and an expression of gladness. You will notice if you
see anyone nod the head to indicate “Yes” that the lips are open rather
than closed, and that there is always a smile or an indication of a
smile to accompany it. In other words, the nod to mean “Yes” is only
another way of saying “I shall be pleased.”




Why Do We Count in Tens?


When man even in his uncivilized state found it necessary to count, the
only implements at hand were his fingers and toes, and as he had ten
toes and ten fingers, he naturally began counting in tens, and has been
doing so ever since.

When we to-day count on our fingers we confine ourselves to our fingers
leaving our toes stay in our shoes, where they naturally belong. But
the first men who counted used both fingers and toes, and so he was
able to count twenty before he had to begin over again, while little
children to-day, when they count with their fingers, must begin where
they started after they reach ten.




What Does Man Mean by Counting Himself?


The expression “counting himself” was originated by the first man who
counted. Such a man would count all of his fingers and toes and the
result would be twenty. Then, so that he would remember the number of
times he had counted himself, he made a mark some place each time he
reached twenty. The mark he made was a mere scratch in the dirt or on a
hoe or something else. To make a scratch you merely, of course, score
the surface of whatever you happen to be scratching on, and that is how
it happened that the word “score” in our language to-day means as a
term in counting, twenty.

There has been a great effort made to change our system of counting in
tens to one where you count in twelves. That would fit in very well
with our system of measuring which is based on the foot of twelve
inches, and of our calendar for recording the passage of time which has
twelve months. There are many arguments in favor of this change, among
the principal of which is the fact that it would make our problems of
division much easier, for our ten can be evenly divided by but two of
our single figures, two and five, whereas twelve can be evenly divided
by four of our single figures, viz., two, three, four and six. It is
believed that sooner or later the system of counting by twelve instead
of ten will be adopted by the entire world for counting everything. As
it is now we do part of our counting by one system and part of it by
another.




Where Did All the Names of People Originate?


There is no scientific plan by which people get their names. There is
not much except curious interest to be gleaned from the study of how
people got their names.

In the earliest days of the world, or at least as soon as men had
learned to speak by sounds, all known persons, places and groups of
human beings must have had names by which they could be spoken of or
to, and by which they were recognized. The study of these names and
of their survival in civilization enables us in certain instances to
tell what tribes inhabited certain parts of the earth now peopled
by descendants of an entirely different race and of another speech
altogether. We learn such things from the names of mountains and other
things, for instance, which still cling to them.

The story of personal names is very complex, but comes from very simple
beginnings. The oldest personal names were those which indicated a
group of people rather than individuals who may have been actually
related to each other or even bound together for reasons of protection
or other convenience. In the races of Asia, Africa, Australia and
America examination shows that groups of people who considered
themselves to be of the same relationship, attached to themselves the
name of some animal or other object, whether animate or inanimate, from
which they claimed to be descended. This animal or object was called
the “totem,” and thus the earliest and most widely spread class and
family names are totemistic. Such groups called themselves by names
from wolves, turtles, bears, suns, moons, birds, and other objects, and
these people wore badges with pictures of the animal or object from
which they took their names to identify them to other people.

When, then, we come to investigate the giving of personal names among
the tribes, we see that most uncivilized races gave a name to each
new-born infant derived from some object or incident. So a new-born
member of the “Sun” tribe would be named “Dawn,” and would be known
as “Dawn” of the “Sun” tribe; or perhaps a new-born son of the tribe
of “Wolf” would be called “Hungry,” and be known as “Hungry Wolf.” A
member of the “Cloud” tribe would be named “Morning,” because he was
born in the morning. He would always be known as “Morning Cloud.”

Later, as society became more established and paternity became
recognized, we find the totem name give way to a gentile name.
Among the Greeks and Romans the system was early adopted and proved
satisfactory. Thus we have Caius Julius Caesar. Caius indicates that
he is Roman; Julius is the gentile name given him and the Caesar a sort
of hereditary nickname. On the other hand, the early Greeks began the
system of introducing a local name instead of the gentile name. Thus
Thucydides (obtained from the grandfather), the son of Olorus, of the
Deme (township) of Halimusia.

~HOW DIFFERENT NAMES ORIGINATED~

This was all right and suited the purposes of the Greeks and Romans,
who had plenty of time to give full explanations in this way. But
in Europe, for instance, civilization demanded more speed, and the
increase of population demanded more names, so that nicknames and names
indicating personal descriptions and peculiarities came into use. Such
names as Long, Short, Small, Brown, White, Green and others of the
same kind came from this source, and as families grew these surnames
stuck to the family and parents gave their children Christian names
to further distinguish them as individuals. Other surnames such as
Fowler, Sadler, Smith, Farmer, etc., became attached to people because
of the occupations in which they were engaged, and yet other names
were derived from places. The owner of an extensive estate would be
designated by a Christian name which might be George (after his King)
and then to indicate his landownership, von (meaning of) Wood, making
the combination of George von Wood, meaning George, the owner of the
place called Wood. On the other hand, he might have working for him a
laborer who lived at the place and, if his name was Hiram, they would,
to indicate where he belonged, put the Wood after the Hiram; but, lest
there be confusion as to his class, they would put an At before the
Wood and make him Hiram Atwood, indicating his Christian name, where he
worked and the fact that he was not a landowner.

Many other names were invented in similar manner. When Adams became so
common that there would likely be confusion on account of there being
so many of them, a son of one of the Adams family would add to the name
the fact that he was a son by writing his name Adamson, and thus start
a new family name. Thus, in the same way also came Willson, Clarkson,
and other names of that kind.

For a long time the Jews had only one word for a name, such as Isaac,
Jacob, Moses, etc. They became so numerous that it was impossible to
distinguish them, and so a commission was named to give surnames to
all the Jews in addition to their other names. As the race was then,
as now, held in derision by the rulers of many nations into which the
tribe had become scattered, the people who had charge of the naming of
the Jews took advantage of the opportunity to make sport of them, and
gave them such names as

Rosenstock (Rose bush),

Rosenszweig (Rose twig),

Rosenbaum (Rose tree),

Blumenstock (Flower bush),

Blumenthal (Flower valley),

etc., etc.

Our Christian names are from similar sources, and while many of them
are well selected because of their beautiful meanings, there are many
of them which mean nothing as words as they were only invented for the
purpose of giving a new name to a new child.




Why Can You Blow Out a Candle?


When you light a candle it burns, because the lighted wick heats the
wax sufficiently to turn it into gases, which mix with the oxygen in
the air and produce fire in the form of light. You know it is not easy
to light a candle quickly. You must hold the lighted match to the wick
until the wax begins to melt and change to gases. As long as the wax
continues hot enough to melt and turn to gas the candle will burn until
all burned up; but if there is a break in the continuous process of
changing the wax to gas, the light will go out. Now, when you blow at
the lighted candle, you blow the gases which feed the flame away from
the lighted wick, and this makes a break in the continuous flow of gas
from the wax to taper, and the light goes out.

[Illustration]




The Story in a Photograph


How Does a Camera Take a Picture?

When we look upon the surface of a mirror we see the image of ourself
and our surroundings. The extent of the view depends upon the size of
the mirror and the distance we are standing from it.

If we hold the mirror close to our face we see only the face, or
perhaps but a portion of it, and the farther away we are the more
the mirror will reflect, only, of course, the various images will be
smaller. The mirror reflecting exactly what the eye sees, without doubt
had a great influence in inducing the experiments that resulted in the
process we call photography.

The taking of a photograph with a camera may in a way be compared
with the action of your eyes, when you gaze upon your reflection in a
mirror, or look at any object or view. Any object in a light strong
enough to render it visible will reflect rays of light from every point.

Now, the eye contains a lens very similar in form to that used in a
camera. This lens collects the rays of light reflected from the object
looked at and brings them to a focus in the back of the eye, forming an
image or picture of whatever we see, just as the mirror collects the
rays of light and reflects them back through the lens of the eye.

Certain nerves transmit the impression of the image so focused in the
back of the eye to the brain and we experience the sensation of sight.


What Is the Eye of the Camera?

The lens is the eye of the camera, and the process we call photography
is the method employed to make permanent the image the eye or lens of
the camera presents to a sensitive surface within the camera.

Fig. 1 shows a simple form of camera, it being merely a light tight box
with a lens fitted to the front, and a means for holding a sensitive
plate at the back, the plate being placed at just the right distance to
focus the rays of light admitted through the lens in exactly the same
manner as the rays of light pass through the lens of the eye and come
to a focus in the back part of the eye.

Now, if we could look inside the camera we would note that the image
was inverted, or upside down.

Fig. 2 will explain this.

The rays of light from “A” pass in a straight line through the lens
“B” until they are interrupted by “C,” upon which they strike, forming
an upside down image of the object “A.” But, you exclaim, “we do not
see things upside down.” No, we do not, because some mental process
readjusts this during the passing of the impression from the eye to our
brain.

Let us suppose we have our camera loaded with its sensitive plate or
film. We select some object or view we wish to photograph, uncover
the lens for an instant, and let the light impress the image upon the
sensitive surface of the plate or film. Now, how are we going to make
this image permanent?

If we were to examine the creamy yellow strip of film upon which the
picture was taken there would seemingly be no difference between its
present appearance and before the snapshot was made.

Now let us suppose that this strip of film is a little trundle bed, and
in it tucked securely away from the light are many hundreds of little
chaps called silver bromides, little roly-poly fellows lying just as
close together as possible, and protected by a coverlet of pure white
gelatine.

~HOW A PHOTOGRAPH IS DEVELOPED~

Until the sudden flash of light in their faces when the picture was
taken, they have been content to lie still and sleep soundly. Now
they are seized with a strange unrest, and each little atom is eager
to do his part in showing your picture to the world. Alone they are
powerless, but they have, all unbeknown to them, some powerful chemical
friends, who, organized and aided by the photographer, will bring
about their transformation. These chemicals, with the help of the
photographer, form themselves into a society called the developer.

The photographer takes just so many of the tiny feathery crystals of
pyro, just so many of the clear little atoms of sulphite of soda, and
just so many little crystals of carbonate of soda, and tumbles them
all into a beaker of clear cold water. Unaided by each other, any one
of these chemicals would be powerless to help their little bromide
of silver friends. The first of these chemicals to go to work is the
carbonate of soda.

He tiptoes softly over to the trundle bed and gently begins turning
back the gelatine covers over the little bromide of silver chaps, so
that Pyro can find them in the dark.

It is Pyro’s mission to transform the little silver bromides into
silver metal, but he is rather an impulsive chap, so he is accompanied
by sulphite of soda, who warns him not to be too rough, and whose sole
mission is to strain his eagerness to help his friends.

“Go slow now,” says Sulphite, “don’t frighten the little silver
bromides, or else you’ll make them cuddle up in heaps, and the picture
won’t be as nice as if you wake them up gently and each little bromide
stayed just where he belonged.”

After all the little silver bromides that the light shone on have been
transformed into metallic silver by the developer, another chemical
friend has to step in and carry away all the little bromides that were
not awakened by the flash of light.

This friend’s name is “Hypo,” and in a few minutes he has carried away
all the little bromides that are still sleeping, so that the trundle
bed with the now awakened and transformed silver bromides will, after
washing and drying, be called a negative, and ready to print your
pictures from.

If we take this negative, as it is called, and hold it up to the
light, we will see that everything is reversed, not only from right to
left, but also that whatever is white or light in color is dark in the
negative, and that what would correspond to the darker parts of our
picture are the lightest in the negative, and it is from these facts
that we give it the name negative.

Now, to get our picture as it should be, we must place this negative in
contact with a sheet of coated paper that is also sensitive to light.

So we place the negative and the sheet of sensitive paper in what is
called a printing frame, with the negative uppermost, so that the light
may shine through the negative, and impress the image upon the sheet of
sensitive paper. Now, it stands to reason that if the lightest parts of
our picture are the darkest in the negative that less light can pass
through such portions of the negative in a given time, so that with the
proper exposure to light the image upon the sheet of sensitive paper
will be a correct picture of whatever the lens saw.

[Illustration: The swiftest thing that the human race has ever put into
motion is the steel projectile of a twelve-inch gun. No human eye can
follow its flight. Released at a pressure of forty thousand pounds to
the square inch--in a heat at which diamonds melt and carbon boils--it
hurls through the air at the rate of twenty-five miles a minute, and
reaches the mark _ahead of its own sound_! (Pictures and story by
courtesy of McClure’s Magazine.)]


TWENTY-FIVE MILES A MINUTE

AN EXCLUSIVE STORY, ILLUSTRATED WITH A SERIES OF REMARKABLE PHOTOGRAPHS
TAKEN WITH THE FASTEST CAMERA IN THE WORLD

BY CLEVELAND MOFFETT

~HOW SHOOTING SHELLS ARE PHOTOGRAPHED~

One of the most progressive branches of our military service is the
Department of Coast Defenses, which, under the far-seeing guidance of
General E. M. Weaver, holds our shores and harbors in a state of alert
preparedness against foreign aggression. At Hampton Roads sits the
Coast Artillery Board, composed of officers and consulting engineers
to whom are referred all problems relating to coast artillery, and who
have the responsibility of testing all new instruments proposed for
artillery use. The purpose of this article is to describe one among
several notable achievements of the Hampton Roads Coast Artillery
School, this particular work having been done by Captain F. J. Behr of
the Coast Artillery Corps, who, after years of effort, has recently
developed a system that makes it possible to take pictures of the
swiftest moving bodies, the great steel projectiles of our biggest
guns--to seize them with the camera’s eye as they hurl through the air
at enormous velocities or at the very moment of their emergence from
the gun muzzles, and to preserve these images, never seen before, for
military study and comparison. Captain Behr was ably assisted in this
work by Engineer J. A. Wilson.

[Illustration: THE FASTEST CAMERA IN THE WORLD

  The big gun, equipped with the fastest camera shutter in the world,
  about to be fired and the shell photographed.

For years a young officer of the Coast Artillery has been trying to
devise a camera so incredibly swift that it will record every stage of
this lightning flight from the gun-barrel to the target. At last he has
succeeded. His photographs--some of them taken one hundred thousandth
of a second apart--have revealed remarkable and unsuspected facts to
the military world. The story of his invention had never before been
told.]


Reckoning in Millionths of a Second.

Some of the increments and decrements of time involved in the series of
photographs herewith published (several of them for the first time) are
as small as one ten-thousandth part of a second. And Captain Behr has
devised a method of taking photographs of projectiles as they arrive at
a steel target and penetrate the target, inch by inch, that involves
increments or decrements of time as small as the one hundred-thousandth
part of a second. To the uninitiated it seems incredible that such
infinitesimal divisions of time can be used in practical calculations;
but every trained physicist knows that in wireless work scientists of
to-day speak casually of experiments that take account of _two-tenths
or one-tenth of a millionth part of a second_!

[Illustration: THE PROJECTILE EMERGING FROM MORTAR

In this photograph--the first of a remarkable series showing five
stages of a moving projectile--the half-ton projectile seems to be
standing still, but really it is traveling at the rate of 900 miles an
hour. The gunners here work in concrete pits 34 feet high. Underneath
the mounts are the powder magazines. Each pit has four mortars usually
served by an entire Coast Artillery Company. The projectiles are the
same as those used in the twelve-inch guns, but less powder is required
because mortar projectiles are hurled high in the air, not straight at
a vessel, and deliver their destructive blows downward from a great
height.]

[Illustration: THE SMOKE RINGS WHICH APPEAR

This second photograph shows the projectile almost entirely out of the
mortar. Its sharp nose may be seen above the “gas-ring” forming at its
upper end. These “gas-rings,” or “smoke-rings,” come without warning,
and only occasionally, perhaps once in eight or ten shots. They rise
swiftly to the height of fifty or a hundred feet, growing larger
and larger, and giving forth a weird, shrieking sound like a second
projectile. Some insist that these “smoke-rings” are as hard as steel,
owing to the enormous compression of their composing gases, and the
story is told of a bird caught in the path of one of them and torn to
pieces.]

What happened to the projectile after it leaves the gun, or after
the discharge of the gun, and before the projectile has had time to
issue from the gun-barrel? What is the action at the muzzle of gases
generated? What shape do these gases assume as they leave the gun? What
causes the much-discussed “gas-rings” that sometimes form when a mortar
is fired, and oftener do not form? What phenomena attend the arrival
of the projectile at a solid steel target? Is the steel actually fused
by the heat of impact? Is it vaporized? Or what? These are some of
the questions that Captain Behr set himself to solve, or to help in
solving, as he worked out his methods of rapid photography. His aims
were strictly military, but his results make fascinating appeal to the
general imagination. Fancy doing anything in the one hundred-thousandth
part of a second!

[Illustration: THE PROJECTILE HIDDEN BY THE SMOKE CONE

In the third photograph the smoke-cone is almost perfect and gives the
famous “powder-puff” effect. It still hides the projectile, although
the latter is traveling at a velocity that would take it from New York
to Chicago in one hour. At night the “gas-rings” present a startling
and fascinating appearance, burning with a reddish orange glow, and
whirling with a complicated double motion, strange opalescent balls,
like rings of Saturn. A study of these photographs--the first record
ever made of the “gas-rings”--has led some experts to the conclusion
that the cause of the rings is defective ramming of the projectile.]

[Illustration: THE PROJECTILE EMERGING FROM SMOKE CONE

The fourth photograph shows the projectile emerging from the smoke-cone
about thirty feet above the muzzle of the mortar. The men who fire
these mortars from the mortar-pits never see the distant target or
vessel they are firing at, but point their mortars according to
directions transmitted to them (usually by telephone) from observers at
distant stations. And so great a degree of precision has been attained
that, on certain practice occasions at Hampton Roads, a record of nine
hits out of ten shots has been scored on a moving target five miles out
in the ocean. This picture shows the smoke-cone as first seen by the
human eye.]

Captain Behr’s general idea was to utilize some phenomena connected
with the discharge to actuate, by electrical connections, a mechanism
that would work a rapid shutter in a properly placed camera. The
phenomenon of concussion was tried first--the smash of air against a
little swinging door; but this was much too slow. The projectile was
hundreds of yards away before the camera had registered its picture.
And that chance was gone!

[Illustration: THE PROJECTILE HIGH IN THE AIR

In the fifth photograph the projectile is seen entirely clear of the
smoke-cone and well started on its long flight. Climbing into the sky
at this steep angle, it will reach a height of from three to six miles
before it begins to descend. There are harbors on our coasts guarded by
so many guns and mortars that if these were fired simultaneously they
could hurl against a given small area a converging rain of projectiles
aggregating more than fifty tons in their combined mass. A minute later
they could hurl another fifty tons against the same small area; and so
on as long as the ammunition lasted.]

In the next trial, several months later, Captain Behr arranged to
have the electrical connections made or broken by the movement of the
gun-carriage itself in recoiling; but the result was unsatisfactory.
Nor was he more fortunate at the succeeding target practice, when,
having placed the apparatus farther forward on the parapet, he had the
camera demolished by the force of the concussion and several blades of
the rapid shutter broken. He was satisfied, now, that his effort to
actuate the camera mechanism from the gun-carriage would never give the
requisite precision in results, and he saw that he must work with a
device functioning more reliably.

In the months that followed before the next target practice, the
Captain did some experimenting, and finally determined making the
projectile itself displace a length of piano-wire fixed across the
muzzle of the gun, and thus actuate the electrical system and operate
the shutter. In this way he eliminated troublesome variables of
recoil, elasticity of the carriage, etc., leaving to determine only
the time element of the electrical system to function. This result was
admirable, and, after taking several similar pictures, the captain
found that he could now operate with great precision--that is, he could
get the same phase of the discharge with almost identical shapes of
gas-cone and smoke-cloud, and he could get these every time.

In the fall of 1912 Captain Behr succeeded in obtaining a series of
extremely rapid photographs showing a twelve-inch mortar battery in
action. In taking these pictures the camera was placed on an elevation
about ten feet above the concrete floor and about sixty feet back of
the mortars. The electrical device for working the shutter was actuated
by the mortar itself in its recoil. These pictures were taken in about
one five-thousandth of a second--which is the more remarkable as the
last two were taken in the shade after 4.30 A.M. The first three were
taken about noon, in the sunshine, as the shadows show.

So great was the precision of the electrical device as to render
possible the photographic recording of these mortar projectiles,
moving at great velocities, in almost any desired position after the
discharge, say two feet away from the muzzle, or six feet away, or
twenty feet away, or right at the muzzle, as shown in the first mortar
picture, where the great projectile has been caught in its flight half
way out of the mortar.


Pictures Never Seen By the Human Eye.

~A CAMERA THAT IS FASTER THAN THE EYE~

It is interesting to note that of these five mortar pictures,
representing five phases of the firing, only the last two are ever
seen by the human eye. The far swifter camera, acting in about one
five-thousandth of a second, has caught all these phases as reproduced
here; but, to the ordinary observer standing by, the first visible
impression after firing is that of the smoke-cone as developed in
Number Four. The strange “powder-puff” effect shown in Number Three is
never seen; nor the earlier effects in Numbers One and Two. Nor is any
sound heard by an observer or by the gun crew until the third or fourth
phase has been reached. This is a matter of simple calculation.

Sound travels through the air very slowly as compared with light, and
in Numbers One, Two, and Three, although the crashing explosion has
taken place and the projectile is already started on its long journey,
the men (even the lanyard man, who is nearest), have heard nothing,
since the sound-waves have not yet had time to reach their ears. Nor
has the mortar itself had time to recoil, as it does presently, down
into the well in the floor of the pit.

The men aboard the towing vessels that drag the floating targets during
gun and mortar practice would seem to be in a dangerous position, since
the tow-line is not more than two hundred yards long for guns and
five hundred yards long for mortars, and a very slight error in aim
or adjustment might cause a deviation of several hundred yards when
the range is eight or ten thousand yards. As a matter of fact, such
errors do not occur, and a gun-pointer who would make a right or left
deviation from the target of ten yards, or at the most fifteen yards
at a distance of five miles, would be considered unfit for his job.
In one or two rare instances a towing vessel has been struck when a
projectile has fallen short and then ricochetted to the right, as it
invariably does owing to its rotation in that direction. The rifling of
the gun-barrel causes this rotation.

[Illustration: This shows one of Captain Behr’s earliest efforts to
photograph the projectile from a twelve-inch gun. The man on the
platform has been adjusting the electrical connections that actuate
the camera mechanism. The halo effect at the muzzle of the gun is due
to compressed air caused by the forward rush of the projectile. The
projectile has not yet emerged from the muzzle of the gun. On the right
is the place where the “Merrimac” and the “Monitor” had their famous
fight.]

Sometimes these great projectiles ricochet several times, and go
bounding over the water as a pebble skips along the surface of a
mill-pond, only there may be the distance of a mile or more between
these giant leaps.


The Projectile Travels Faster Than the Sound It Makes.

A strange phenomenon is witnessed by the observer on a towing vessel as
he looks, rather uneasily perhaps, toward the distant shore battery,
that seems to be firing straight at him. First there is a flash and
a puff of smoke; then nothing for a period of seconds, while the
projectile is on its way; then suddenly a great splash as the mass of
iron strikes the water. Up to this moment there has been no sound of
the discharge, no sound of the projectile, since it travels faster than
the sound-waves; but now, _after_ it has buried itself in the ocean, is
heard its own unmistakable voice, a low, buzzing _um-m-m-m_ approaching
from the shore. The projectile itself has arrived _before_ the sound
that it makes in transit, and the sound arrives afterward. Last of all
is heard the boom of the discharge.

[Illustration: A GUN THAT PHOTOGRAPHED ITS OWN SHOT

In this beautiful picture the hurling projectile was itself the
photographer: that is, in passing out of the gun-barrel, it broke a
length of piano-wire stretched across the muzzle and thus automatically
closed an electrical circuit that actuated the camera mechanism. And so
rapid was the shutter that the great shot hurled forth in the discharge
photographed here has not yet had time to issue from the smoke-cone,
where it is still hidden.]

Owing to the great velocity of gun projectiles, it is almost impossible
for an observer near the target to see them as they approach; but a
trained eye can discern the slower moving mortar projectiles as they
drop out of the sky, shrieking as they come, curving downward from a
height of four or five miles, half a ton falling from a height of four
or five miles.

[Illustration: EXPLODING A SUBMARINE MINE

This photograph illustrates another important form of coast
defense--the submarine mine. A target about 5 by 5 feet, with a red
flag at its apex, is towed across the mine-field, the mines being
exploded electrically from a shore station several miles away. The
methods of laying and exploding these mines are carefully kept secrets.
In this case a charge of five hundred pounds of the newest explosive
was used. Fragments of the shattered target and mine-buoy are seen at
the right of the picture. Tons of water are hurled into the air by
these explosions, and hundreds of fish are killed or stunned.]

It is difficult to realize what an enormous force is released when one
of these twelve-inch guns is discharged. The pressure inside of the
gun behind the projectile is between thirty-five and forty thousand
pounds to the square inch. No engine or machine made by man produces
anything like this pressure. The boiler pressure in steam-engines,
or in big turbines driven by superheated steam, does not exceed two
hundred or three hundred pounds to the square inch. The huge hydraulic
presses that would crumple up a steel girder do not exert a pressure
of more than one thousand pounds to the square inch. The only reason
a gun-barrel can resist this pressure (forty thousand pounds to the
square inch) is that it is built up in a series of concentric steel
hoops or tubes shrunk one over the other until there is a resistance
capacity of from seventy thousand to ninety thousand pounds to the
square inch. Even at rest, the barrels of these great guns are under
such enormous compression, from being thus squeezed within these outer
steel coverings, that, if the retaining steel jackets were suddenly
cut, the tubes would blow themselves into pieces from the violent
reaction of release.

Not only does this smokeless powder, burning inside these guns,
produce enormous pressure, but it generates inconceivably great heat.
Water boils at 100° Centigrade; iron melts at 1400°; platinum and
the most resistant metals at 2900°; while the hottest thing on earth
is the temperature of the electric arc, in which carbon boils. This
temperature is between 3000° and 4000° Centigrade, and is believed to
be the same as that of these great powder chambers when the gun is
fired. Thus a diamond, the hardest substance known, would melt in the
barrel of a twelve-inch gun at the moment of discharge. The consequence
is that at each discharge of a big gun a thin skin of metal inside
the barrel is literally fused, and this leads to rapid erosion of
the softened surfaces under the tearing pressure of gases generated.
The rifling is worn away; the band over the projectile becomes
loose-fitting; and soon the huge gun, that has cost such a great sum,
is rendered unfit for service. The life of a twelve-inch gun is only
450 rounds, that is, the gun would be worn out if fired every three
minutes for a single day. After that a new life may be given it by
boring out the inner tube and putting in a new steel lining.


A Secret for Which Foreign Governments Would Pay Millions.

A few words may be added about the formidable smokeless powder used in
these great guns. This powder, in spite of its terrible power, is of
innocent appearance, and a small stick of it may be held safely in the
hand while it burns with a vivid yellowish flame. There is no danger
of its exploding or detonating like gun-cotton, and yet it is made
from gun-cotton, treated by a colloiding process that is one of our
jealously guarded military secrets. There are foreign governments that
would give millions to know exactly how this powder is made and how it
is preserved for years without deterioration. The recent destruction of
two ships of the French navy was due, it is believed, to deterioration
of their smokeless powder.

[Illustration]




Why Do Some Eyes In a Picture Seem to Follow Us?


If a person’s picture is taken with the eyes of the person looking
directly into the lens or opening of the camera, then the eyes in
the picture will always be directly on and appear to follow whoever
is looking at it. This is also true of paintings. If a subject being
painted is posed so as to look directly at the painter, and the artist
paints the picture with the eyes so pointed, then the eyes of the
picture will follow you. When you are looking at a picture of a person
and the eyes do not follow you, you will know at once that he was not
looking at the camera or artist when the picture was being taken or
painted.

[Illustration]




Where Does a Light Go When It Goes Out?


~WHY YOU CAN BLOW OUT A CANDLE~

To understand the answer to this question fully you will first have to
learn what light is, and particularly that it is not the flame from
the gas jet or of the lamp or candle that is actually the light, but
that light consists of rays or waves in the ether, which is constantly
in all space and even in our bodies, coming from the something that
is burning. This in the instance above mentioned would be the gas
burning as it comes out of the gas jet, the oil in the lamp as it comes
up through the wick or the flame of the candle. We are apt to call
a lighted gas jet a lamp, or a candle, light, because it is steady.
Really, however, there is no such thing as keeping light in a room in
an actual sense, for rays of light travel from the substance which
produces them faster than anything else we know of in the world. The
first thing a light wave does when it is once created is to go some
place, and it does this at the rate of 186,000 miles per second. If it
cannot penetrate the walls of the room it is either reflected back in
the direction from which it came or transformed by the objects which it
strikes into some other kind of energy.

When you look at the rays coming from a gas jet, you do not see one ray
for more than, say the millionth part of a second, but because these
rays of light come so fast one after the other from the burning jet and
spread in all directions, they seem to be continuous.

So you see that the rays of light are going away as fast as they are
coming from the gas jet. They either go on as light or, as said above,
are changed into other forms of energy when they strike things they
cannot penetrate in the form of light, or rather one thing, which is
heat. A large part of it goes into the air in the room in the form of
heat, as you well know, now that it is called to your attention. Some
of it goes into the furniture and some of it is changed into another
form of heat, which, combining with the chemicals in other things it
mixes with, changes their appearance and usefulness. As, for instance,
the carpets and hangings in the room, the colors of which become faded
when exposed to light rays too much. The heat from the light rays is
responsible for the fading of colors in our garments as well.

When you “put out the light,” as we say, or turn off the gas, you cut
off the source of light. Really, then, our expression that “the light
goes out” is only true while the gas is lighted, for from the flaming
gas jet the light is going out all the time, whereas when the gas is
turned off no light is being produced, and when you turn off the gas
you do not turn out the light, but only that which makes light.




Why Does a Fire Go Out?


Fire will go out naturally when there is nothing left to burn, or it
will go out if it cannot secure enough oxygen out of the air to keep it
going. In the first case it dies what we might call a “natural death,”
and in the latter case the fire practically suffocates. The fire in
the open fireplace, if it has plenty of air, will burn up everything
burnable that it can reach. The stones of the fireplace or other parts
of a stove will not burn, because they have already been burned, and
you cannot burn anything a second time, if all of the oxygen in it was
burned out of it the first time.

Now, then, to burn up a thing, you must first start a fire under it,
and then keep a constant draft of air playing on it from beneath, or
the fire will die out. The more difficult a thing is to burn, the more
important it is that you have plenty of draft. If the ashes accumulate
under the fire the air cannot go through them in sufficient quantity
and the fire will go out. Other things which prevent the current of air
from going up through the fire will cause it to go out. That is why we
close the lower door of the furnace, to keep the fire from burning out.
When we shut off the draft of air from below, the fire in the furnace
burns slowly, i. e., it just hangs on, so to speak.




Why Does a Lamp Give a Better Light With the Chimney On?


When a lamp is burning without a chimney it generally smokes. That
is because the oil which is coming up through the wick is being only
partially burned. The carbon, which is about one-half of what the oil
contains, is not being burned at all, and goes off into the air in
little black specks with the gases which are thrown off. The reason
the carbon is not burned when the chimney is off is that there is not
sufficient oxygen from the air combining with it, as it is separated
from the oil in the partial combustion that is going on. To make the
carbon in the oil burn you must mix it with plenty of oxygen at a
certain temperature, and this can only be done by forcing sufficient
oxygen through the flame to bring the heat of the flame to the point
where the carbon will combine with it and burn. When you put the
chimney on the lamp you create a draft which forces more oxygen through
the flame, brings the heat up to the proper temperature and enables the
carbon to combine with it and burn. When you take the chimney off again
the heat goes down, when the draft is shut off and the lamp smokes
again.

The chimney also protects the flame of the lamp from drafts from the
sides and above, and helps to make a brighter light, because a steady
light is brighter than a flickering one.

The draft created by the chimney also forces the gases produced by the
burning oil up and away from the flame. Some of these gases have a
tendency to put out a light or a fire.




Does Light Weigh Anything?


To get at the answer to this question we must go back to the definition
of light. Light is a wave in the ether and contains no particles of
matter. It, therefore, does not weigh anything at all.

When men had studied light thoroughly, however, they came to the
conclusion that it must have the power of pressure, which, from the
standpoint of results, would amount to the same thing as having weight.
They reasoned that if you had a perfect balance and let sunlight shine
down on one of the sides of the balance, that side should go down under
the pressure of light. In their first experiments along this line men
failed to show that under such conditions the side of the balance on
which the light shone did go down, but by continuous experiments it was
proved finally that the light did exert a sufficient pressure to cause
the scales to go down, and in effect this is the same as having weight;
but this has been found to be a common property of rays of various
kinds, including heat, and we, therefore, do not speak of this quality
as weight, but as the power of radiating pressure.




Why Does a Stick Seem to Bend When Put in Water?


When light passes from one medium to another, as for example from glass
or water to air, or from air or glass to water, the rays of light
change their course, thus making them seem to be bent or broken. The
rays of light from the part of the stick in the water take a different
direction from the rays from the part which is out of the water, giving
the appearance of breaking or bending at the place where the air and
water meet. It is, of course, the light rays which are bent and not the
object itself.

This bending or changing of the path of light rays is called
refraction. If you place a coin in a glass of water so that it may be
viewed obliquely, you can apparently see two coins, a small one through
the surface of the water and another apparently magnified through the
side of the glass.

This is due only to the absolute principle that rays of light change
their direction in passing from one thing to another, and on this
principle of the rays of light our optical instruments, including the
microscope, the telescope, the camera and eyeglasses are based.




What Makes the Stars Twinkle?


I might tell you, just to show how clever I am, that stars do not
twinkle at all, and leave you with that for an answer. But since they
really do seem to twinkle, and that is what causes your question,
I will tell you. As we have already learned in our talks about the
stars and the sky in general, the stars are suns which are constantly
throwing off light, just as our sun gives us light, and when this light
strikes the air which surrounds the earth it meets many objects--little
particles of dust and other things always floating about in it. The
light comes to us in the form of rays from the stars and some of
these rays strike particles of various kinds in the air and are thus
interfered with. If you are looking at a lighted window some distance
away and there are a lot of boys and girls or men and women running
past the window, one after the other, rapidly, it will make the
light in the window appear to twinkle. The twinkling is due to the
interference which the rays of light encounter while traveling toward
the eye.




Why Does an Onion Make the Tears Come?


That is nature’s way of protecting the eyes from the smarting which the
onion would cause in your eyes if the tears did not come quickly and
overcome the bad effect so produced. Tears are provided for washing the
ball of your eyes. Every time you wink a little tear is released from
under the eyelid, and the wink spreads it all over the eyeball. This
washes down the front of the eyeball and cleanses it of all dust and
other things that fly at the eye from the air. Then the tear runs along
a little channel, much like a trough, at the lower part of the eye,
and out through a little hole in the eye, and in this case the tear is
really only an eye-wash. Many things, but more often sadness or injured
feelings, start the tears coming so fast from under the eyelid that the
little trough at the bottom and the hole in the corner of the eye are
too small to hold them or carry them off, so they roll over the edge of
the lower eyelid and down the face. These are what we call tears. Among
other things that will cause tear-glands to cause an over-supply of
eye-wash to come down, are onions. What they give off is very trying to
the eyes, and so, just as soon as the something which an onion throws
off hits the eyeball, the nerves of the eye telegraph the brain to turn
on the tears quickly, and they come in a little deluge and counteract
the bad effect of the onion.

[Illustration: SOME REMARKABLE PICTURES WITH A FAST CAMERA]

[Illustration]

[Illustration]

[Illustration]

[Illustration]

[Illustration: THE CAVE MAN OF PREHISTORIC TIMES WHO UNCONSCIOUSLY
INVENTED AMMUNITION]




The First Missile


~HOW MAN LEARNED TO SHOOT~

A naked savage found himself in the greatest danger. A wild beast,
hungry and fierce was about to attack him. Escape was impossible.
Retreat was cut off. He must fight for his life--but how?

Should he bite, scratch or kick? Should he strike with his fist? These
were the natural defences of his body, but what were they against the
teeth, the claws and the tremendous muscles of his enemy? Should he
wrench a dead branch from a tree and use it for a club? That would
bring him within striking distance to be torn to pieces before he could
deal a second blow.

There was but a moment in which to act. Swiftly he seized a jagged
fragment of rock from the ground and hurled it with all his force at
the blazing eyes before him; then another, and another, until the
beast, dazed and bleeding from the unexpected blows, fell back and gave
him a chance to escape. He knew that he had saved his life, but there
was something else which his dull brain failed to realize.

He had invented arms and ammunition!

In other words, he had needed to strike a harder blow than the blow of
his fist, at a greater distance than the length of his arm, and his
brain showed him how to do it. After all, what is a modern rifle but a
device which man has made with his brain permitting him to strike an
enormously hard blow at a wonderful distance? Firearms are really but a
more perfect form of stone-throwing, and this early Cave Man took the
first step that has led down the ages.

This strange story of a development has been taking place slowly
through thousands and thousands of years, so that today you are able to
take a swift shot at distant game instead of merely throwing stones.

[Illustration: THE SLING MAN IN ACTION

PRACTICE DEVELOPED SOME WONDERFUL MARKSMEN AMONG THE USERS OF THIS
PRIMITIVE WEAPON]

We do not know the name of the man who invented the sling. Possibly
he did not even have a name, but in some way he hit upon a scheme
for throwing stones farther, harder, and straighter than any of his
ancestors.

The men and women in the Cave Colony suddenly found that one
bright-eyed young fellow, with a little straighter forehead than the
others, was beating them all at hunting. During weeks he had been going
away mysteriously, for hours each day. Now, whenever he left the camp
he was sure to bring home game, while the other men would straggle back
for the most part empty-handed.

Was it witchcraft? They decided to investigate.

Accordingly, one morning several of them followed at a careful distance
as he sought the shore of a stream where water-fowl might be found.
Parting the leaves, they saw him pick up a pebble from the bank and
then to their surprise, take off his girdle of skin and place the stone
in its center, holding both ends with his right hand.

Stranger still, he whirled the girdle twice around his head, then
released one end so that the leather strip flew out and the stone shot
straight at a bird in the water.

The mystery was solved. They had seen the first slingman in action.

The new plan worked with great success, and a little practice made
expert marksmen. We know that most of the early races used it for
hunting and in war. We find it shown in pictures made many thousands of
years ago in ancient Egypt and Assyria. We find it in the Roman Army
where the slingman was called a “funditor.”

Surely, too, you remember the story of David and Goliath when the young
shepherd “prevailed over the Philistine with a sling and with a stone.”

Yet slings had their drawbacks. A stone slung might kill a bird or even
a man, but it was not very effective against big game.

What was wanted was a missile to pierce a thick hide.

Man had begun to make spears for use in a pinch, but would you like
to tackle a husky bear or a well-horned stag with only a spear for a
weapon?

No more did our undressed ancestors. The invention of the greatly
desired arm probably came about in a most curious way.

Long ages ago man had learned to make fire by patiently rubbing two
sticks together, or by twirling a round one between his hands with its
point resting upon a flat piece of wood.

[Illustration: THE “LONG BOW” IN SHERWOOD FOREST

ONE OF ROBIN HOOD’S FAMOUS BAND ENCOUNTERS A SAVAGE TUSKER AT CLOSE
RANGE]

In this way it could be made to smoke, and finally set fire to a tuft
of dried moss, from which he might get a flame for cooking. This was
such hard work that he bethought him to twist a string of sinew about
the upright spindle and cause it to twirl by pulling alternately at
the two string ends, as some savage races still do. From this it was
a simple step to fasten the ends of the two strings to a bent piece
of wood, another great advantage since now but one hand was needed to
twirl the spindle, and the other could hold it in place. This was the
“bow-drill” which also is used to this day.

But bent wood is apt to be springy. Suppose that while one were
bearing on pretty hard with a well-tightened string, in order to bring
fire quickly, the point of the spindle should slip from its block.
Naturally, it would fly away with some force if the position were just
right.

[Illustration: DEER STALKING WITH THE CROSSBOW

THIS COMPACT ARM WITH ITS SMALL BOLT AND GREAT POWER WAS POPULAR WITH
MANY SPORTSMEN]

There was one man who stopped short when he lost his spindle, for a
red-hot idea shot suddenly through his brain.

Once or twice he chuckled to himself softly. Thereupon he arose and
began to experiment. He chose a longer, springier piece of wood, bent
it into a bow, and strung it with a longer thong. He placed the end of
a straight stick against the thong, drew it strongly back, and released
it.

The shaft whizzed away with force enough to delight him, and lo, there
was the first Bow-and-Arrow!

Armed with his bow-and-arrow, man now was lord of creation. No longer
was it necessary for him to huddle with his fellows in some cave to
avoid being eaten by prowling beasts. Instead he went where he would
and boldly hunted the fiercest of them. In other words, his brain was
beginning to tell, for though his body was still no match for the lion
and the bear, he had thought out a way to conquer them.

Also he was better fed with a greater variety of game. And now, free
to come and go wherever he might find it, he was able to spread into
various lands and so to organize the tribes and nations which at last
gave us civilization and history.

A new weapon now came about through warfare. Man has been a savage
fighting animal through pretty much all his history, but while he tried
to kill the other fellow, he objected to being killed himself.

Therefore he took to wearing armor. During the Middle Ages he piled on
more and more, until at last one of the knights could hardly walk, and
it took a strong horse to carry him. When such a one fell, he went over
with a crash like a tin-peddler’s wagon, and had to be picked up again
by some of his men. Such armor would turn most of the arrows. Hence
invention got at work again and produced the Crossbow and its bolt. We
have already learned how the tough skin of animals brought about the
bow; now we see that man’s artificial iron skin caused the invention of
the crossbow.

What was the Crossbow? It was the first real hand-shooting machine. It
was another big step toward the day of the rifle. The idea was simple
enough. Wooden bows had already been made as strong as the strongest
man could pull, and they wished for still stronger ones--steel ones.
How could they pull them? At first they mounted them upon a wooden
frame and rested one end on the shoulder for a brace. Then they took to
pressing the other end against the ground, and using both hands. Next,
it was a bright idea to put a stirrup on this end, in order to hold it
with the foot.

Still they were not satisfied. “Stronger, stronger!” they clamored;
“give us bows which will kill the enemy farther away than he can shoot
at us! If we cannot set such bows with both arms let us try our backs!”
So they fastened “belt-claws” to their stout girdles and tugged the bow
strings into place with their back and leg muscles.




Who First Discovered the Power of Gunpowder?


Probably the Chinese, although all authorities do not agree. Strange,
is it not, that a race still using crossbows in its army should have
known of explosives long before the Christian Era, and perhaps as far
back as the time of Moses? Here is a passage from their ancient Gentoo
Code of Laws: “The magistrate shall not make war with any deceitful
machine, or with poisoned weapons, or with cannons or guns, or any kind
of firearms.” But China might as well have been Mars before the age of
travel. Our civilization had to work out the problem for itself.

It all began through playing with fire. It was desired to throw fire on
an enemy’s buildings, or his ships, and so destroy them.

Burning torches were thrown by machines, made of cords and springs,
over a city wall, and it became a great study to find the best burning
compound with which to cover these torches. One was needed which would
blaze with a great flame and was hard to put out.

Hence the early chemists made all possible mixtures of pitch, resin,
naphtha, sulphur, saltpeter, etc.; “Greek fire” was one of the most
famous.

Many of these were made in the monasteries. The monks were pretty much
the only people in those days with time for study, and two of these
shaven-headed scientists now had a chance to enter history. Roger Bacon
was the first. One night he was working his diabolical mixture in the
stone-walled laboratory, and watched, by the flickering lights, the
progress of a certain interesting combination for which he had used
pure instead of impure saltpeter.

Suddenly there was an explosion, shattering the chemical apparatus and
probably alarming the whole building. That explosion proved the new
combination was not fitted for use as a thrown fire; it also showed the
existence of terrible forces far beyond the power of all bow-springs,
even those made of steel.

Roger Bacon thus discovered what was practically gunpowder, as far
back as the thirteenth century, and left writings in which he
recorded mixing 11.2 parts of the saltpeter, 29.4 of charcoal, and
29 of sulphur. This was the formula developed as the result of his
investigations.

Berthold Schwartz, a monk of Freiburg, studied Bacon’s works and
carried on dangerous experiments of his own, so that he is ranked with
Bacon for the honor. He was also the first one to rouse the interest of
Europe in the great discovery.

[Illustration: THE “KENTUCKY RIFLE” WITH ITS FLINT-LOCK WAS ACCURATE
BUT MUST BE MUZZLE-CHARGED]

~THE FIRST REAL FIRE ARMS~

And then began the first crude, clumsy efforts at gunmaking. Firearms
were born.

Hand bombards and culverins were among the early types. Some of these
were so heavy that a forked support had to be driven into the ground,
and two men were needed, one to hold and aim, the other to prime and
fire.

Improvements kept coming, however. Guns were lightened and bettered in
shape. Somebody thought of putting a flash pan, for the powder, by the
side of the touch-hole, and now it was decided to fasten the slow-match
in a movable cock upon the barrel, and ignite it with a trigger. These
matches were fuses of some slow-burning fiber, like tow, which would
keep a spark for a considerable time. Formerly they had to be carried
separately, but the new arrangement was a great convenience and made
the match-lock. The cock, being curved like a snake, was called the
“serpentine.”

About the time sportsmen were through wondering at the convenience
of the match-lock, they began to realize its inconvenience. They
found that they burned up a great deal of fuse, and were hard to keep
lighted. Both statements were true, so inventors racked their brains
again for something better. They all knew you could bring sparks with
flint and steel, and that seemed an idea worth working on. A Nuremberg
inventor, in 1515, hit on the wheel-lock. In this a notched steel
wheel was wound up with a key like a clock. Flint or pyrite was held
against the jagged edge of the wheel by the pressure of the serpentine.
You pulled the trigger, then “whirr,” the wheel revolved, a stream of
sparks flew off into the flash-pan, and the gun was discharged.

[Illustration: WHEEL-LOCK RIFLE]

This gun worked beautifully, but it was expensive. Wealthy sportsmen
could afford them, and so for the first time firearms began to be used
for hunting. Some of these sixteenth and seventeenth century nabobs had
such guns of beautiful workmanship, so wrought and carved and inlaid,
that they must have cost a small fortune. You will find them in many
large museums to this day.

But now the robbers had their turn. There are two stories of the
invention of the flint-lock. Both deal with robbers, both have good
authority, and both may be true, for inventions sometimes are made
independently in different places.

One story runs that the flint-lock which was often styled “Lock à la
Miquelet,” from the Spanish word, “Miquelitos”--marauders--told its
origin in its name. The other is, that the flint-lock was invented in
Holland by gangs of thieves, whose principal business was to steal
poultry.

In either case the explanation is easy. The match-lock showed its fire
at night and wouldn’t do for thieves, the wheel-lock was too expensive,
so again necessity became the mother of a far-reaching invention.

Everybody knows what the flint-lock was like. You simply fastened a
flake of flint in the cock and snapped it against a steel plate. This
struck off sparks which fell into the flash-pan and fired the charge.

It was so practical that it became the form of gun for all uses; thus
gunmaking began to be a big industry. Invented early in the seventeenth
century, it was used by the hunters and soldiers of the next two
hundred years. Old people remember when flint-locks were plentiful
everywhere. In fact, they are still being manufactured and are sold
in some parts of Africa and the Orient. One factory in Birmingham,
England, is said to produce about twelve hundred weekly, and Belgium
shares in their manufacture. Some of the Arabs use them to this day in
the form of strange-looking guns with long, slender muzzles and very
light, curved stocks.

There were freak inventors in the flint-lock period just as there are
to-day. Some of them wrestled with the problem of repeating guns,
and put together a number of barrels, even seven in the case of one
carbine. Others tried revolving chambers, like our revolvers, and still
others, magazine stocks. Pistols came into use in many interesting
shapes, but these were too practical to be considered freaks.

~WHY WE CALL THEM PISTOLS~

Pistols, by the way, are named from the town of Pistola, Italy, where
they are said to have been invented and first used.

We must not forget that rifling was invented about the time that the
wheel-lock appeared, and had a great deal to do with the improvement
of shooting. Austrians claim its invention for Casper Zollner, of
Vienna, who cut straight grooves in the barrel’s bore. His gun is said
to have been used for the first time in 1498, but the Italians seem
to have still better warrant as these significant words appear in old
Latin Italian, under date of July 28th, 1476, in the inventory of the
fortress of Guastalla: “Also one iron gun made with a twist like a
snail shell.” The rifling made the bullet spin like a top as it flew
through the air, thus greatly improving its precision.

In the year 1807 the Rev. Alexander John Forsythe, LL.D., got his
patent papers for something far better than even the steady old flint.
He had invented the percussion system. In some form this has been used
ever since. Which is to say that when the hammer of your gun falls, it
doesn’t explode the powder, although it seems to. Instead it sets off a
tiny portion of a very sensitive chemical compound called the “primer,”
and the explosion of this “primer” makes the powder go off. Of course,
the two explosions come so swiftly that your ear hears only a single
bang.

Primers were tried in different forms called “detonators,” but the
familiar little copper cap was the most popular. No need to describe
them. Millions are still made to be used on old-fashioned nipple guns,
even in this day of fixed ammunition.

But now we come to another great development, the Breech-loader.

[Illustration: THE MODERN AUTOMATIC RIFLE

THE MODERN SPORTSMAN WITH HIS AUTOMATIC RIFLE IS PREPARED FOR ALL
EMERGENCIES]

Perhaps you have had to handle an old muzzle-loader. It was all right
so long as you knew of nothing better, but think of it now that you
have your beautiful breech-loader. Do you remember how sometimes you
overloaded, and the kick made your shoulder lame for a week? Or how,
when you were excited you shot away your ramrod? The gun fouled too,
and was hard to clean, the nipples broke off, the caps split, and the
breeches rusted so that you had to take them to a gunsmith. Yes, in
spite of the game it got, it was a lot of trouble, now you come to
think of it. How different it all is now!

[Illustration: ASSEMBLING REPEATING SHOTGUNS AND RIFLES]

Breech-loaders were hardly new. King Henry VIII of England, he of the
many wives, had a match-lock arquebus of this type dated 1537. Henry IV
of France even invented one for his army, and others worked a little
on the idea from time to time. But it wasn’t until fixed ammunition
came into use that the breech-loader really came to stay--and that
was only the other day. You remember that the Civil War began with
muzzle-loaders and ended with breech-loaders.

[Illustration: ASSEMBLING AUTO SHOTGUNS]

[Illustration: SOME OF THE SHOOTING TESTS]

Houiller, the French gunsmith, hit on the great idea of the cartridge.
If you were going to use powder, ball and percussion primer to get your
game, why not put them all into a neat, handy, gas-tight case?


THE FIRST AMERICAN MADE GUNS

~HOW THE FIRST AMERICAN GUN WAS MADE~

Two men, a smith and his son, both named Eliphalet Remington, in
1816, were working busily one day at their forge in beautiful Ilion
Gorge, when, so tradition says, the son asked his father for money to
buy a rifle, and met with a refusal. The request was natural for the
surrounding hills were full of game. The father must have had his own
reasons for refusing, but it started the manufacture of guns in America.

Eliphalet, Jr., closed his firm jaws tightly, and began collecting
scrap iron on his own account. This he welded skillfully into a
gun-barrel, walked fifteen miles to Utica to have it rifled, and
finally had a weapon of which he might well be proud.

[Illustration: TYPES OF CARTRIDGES]

In reality, it was such a very good gun that soon the neighbors ordered
others like it, and before long the Remington forge found itself hard
at work to meet the increasing demand. Several times each week the
stalwart young manufacturer packed a load of gun-barrels upon his back,
and tramped all the way to Utica where a gunsmith rifled and finished
them. At this time there were no real gun-factories in America,
although gunsmiths were located in most of the larger towns. All
gun-barrels were imported from England or Europe.


A VISIT TO A CARTRIDGE FACTORY

~HOW AMMUNITION IS MADE~

One of the first shocks you get when you start your visit through a
cartridge factory is the matter-of-fact way in which the operatives,
girls in many cases, handle the most terrible compounds. We stop, for
example, where they are making primers to go in the head of your loaded
shell, in order that it may not miss fire when the bunch of quail
whirrs suddenly into the air from the sheltering grasses. That grayish
pasty mass is wet fulminate of mercury. Suppose it should dry a trifle
too rapidly. It would be the last thing you ever did suppose, for there
is force enough in that double handful to blow its surroundings into
fragments. You edge away a little, and no wonder, but the girl who
handles it shows no fear as she deftly but carefully presses it into
moulds which separate it into the proper sizes for primers. She knows
that in its present moist condition it cannot explode.

[Illustration: INSPECTING METALLIC SHELLS]

[Illustration: EXAMINING PAPER SHELLS]

[Illustration: WEIGHING BULLETS]

Or, perhaps, we may be watching one of the many loading machines.
There is a certain suggestiveness in the way the machines are separated
by partitions. The man in charge takes a small carrier of powder from a
case in the outside wall and shuts the door, then carefully empties it
into the reservoir of his machine, and watches alertly while it packs
the proper portions into the waiting shells. He looks like a careful
man, and needs to be. You do not stand too close.

[Illustration: SHOOTING ROOM OF BALLISTICS DEPARTMENT]

[Illustration: CHRONOGRAPH FOR MEASURING]

The empty carrier then passes through a little door at the side of the
building, and drops into the yawning mouth of an automatic tube. In the
twinkling of an eye it appears in front of the operator in one of the
distributing stations, where it is refilled, and returned to its proper
loading machine, in order to keep the machine going at a perfectly
uniform rate; while at the same time it allows but a minimum amount
of powder to remain in the building at any moment. Each machine has
but just sufficient powder in its hopper to run until a new supply can
reach it. Greater precaution than this cannot be imagined, illustrating
as it does that no effort has been spared to protect the lives of the
operators.

[Illustration: PUTTING METAL HEADS ON PAPER SHOT SHELLS]

It is remarkable that, in an output of something like four million per
day, every cartridge is perfect.

Such things are not accidental. The secret is, inspection.

~TESTING MATERIALS AND PRODUCTS~

Let us see what that means. It means laboratory tests to start with.
Here are brought many samples of the body paper, wad paper, metals,
waterproofing mixture, fulminate of mercury, sulphur, chlorate of
potash, antimony sulphide, powder, wax, and other ingredients, and
even the operating materials such as coal, grease, oil, and soaps.
In the laboratory we see expert chemists and metallurgists with
their test-tubes, scales, Bunsen burners, retorts, tensile machines,
microscopes, and other scientific looking apparatus, busily hunting
for defects.

For example, one marker is examining a supply of cupro-nickel, such as
is used in jacketing certain bullets. A corner of each strip is first
bent over at right angles, then back in the other direction until it
is doubled, then straightened. It does not show the slightest sign of
breaking or cracking, in spite of the severe treatment, therefore it is
perfect. Let but the least flaw appear, and the shipment is rejected.

[Illustration: WHAT A SHOT TOWER LOOKS LIKE

  SHOT TOWER--TALLEST BUILDING IN CONNECTICUT]

[Illustration:

  LARGEST CARTRIDGE EQUALS MORE
  THAN 1,000,000 OF SMALLEST
  (HELD ON HAND)]

Two large iron cylinders descend in the center, coming down through the
ceiling from above; we are invited to look through an open port in one
of these.

We see nothing but the whitened opposite wall, against which a light
burns.

It appears absolutely empty, though within it is raining such a swift
shower of invisible metal that if we were to stretch our hands into the
apparently vacant space they would be torn from our arms.

A large water tank below is churned into foam with the impact of the
falling shot, and as we look downward we make out finally the haze of
motion. It is so interesting that we take the elevator and rise ten
stories to the source of the shower.

Here high in the air are the large caldrons where many pigs of lead,
with the proper alloy, are melted into a sort of metallic soup. This
is fed into small compartments containing sieves or screens, through
the meshes of which the shining drops appear and then plunge swiftly
downward.

But this only begins the process. Taken from the water tanks and
hoisted up again, the shot pellets, in a second journey down, through
complicated devices, are sorted, tumbled, polished, graded, coated with
graphite, and finally stored.

  The pictures shown in this story were prepared especially to
  illustrate this story of “How Man Learned to Shoot” by the
  Searchlight Library for the Remington Arms Company.

[Illustration: FORGING A MONSTER GUN

  Photo by Bethlehem Steel Co.

This photograph shows gun ingots after being “stripped” and “cored.”]

[Illustration:

  Photo by Bethlehem Steel Co.

This photograph shows a gun ingot in the process of being forged under
forging press.]

[Illustration:

  Photo by Bethlehem Steel Co.

This photograph shows a gun being fired at the Proving Grounds for
test.]




The Parts of a Big Gun


~THINGS TO KNOW ABOUT A BIG GUN~

Before going into a description of the manufacture of a big gun it
would be well to understand the following definitions:

The “breech” of a gun is its rear-end, or that end into which the
projectile and powder charge are loaded.

The “muzzle” of a gun is its forward end.

By “calibre” is meant the inside diameter of the gun in inches. A
5-inch gun is one of “minor calibre,” and one of 14-inches a gun of
“major calibre.”

The length of a gun is never expressed in inches or feet, but in the
_number of times_ that its calibre is divisible into its length; thus,
when we say a 12-inch 50-calibre gun, we mean a gun of 12 inches in
diameter, and 12 times 50, or 600 inches long.

The “bore” is the hole extending through the center of the gun, from
the rear face of the liner to its forward end.

The “powder chamber” is the rear part of the bore, and extends from the
face of the breech plug when closed to the point where the “rifling”
begins. The powder chamber is slightly larger in diameter than the rest
of the bore.

The “rifling” is the name given to the spiral grooves which are cut
into the surface of the bore of the gun, and give to the projectile its
rotary motion when the gun is fired.

With the advent of “iron-clads” and heavily armored fortresses, it
became necessary to increase the power of the guns in use, until to-day
a 14-inch gun of 45 calibres fires a projectile weighing 1400 pounds,
with an initial velocity of 2600 feet per second. An idea of this
initial velocity may be better obtained by comparison when you realize
that a train going sixty miles an hour is only traveling at the rate
of 88 feet per second. Now, in order to produce such wonderful power in
a gun, great pressure must be generated in the bore, and it was soon
found that a one-piece gun, whether cast or forged, could not withstand
such pressures.

To begin with, we may consider this one-piece gun, or any gun, as a
tube which must withstand a great pressure from within, so that when
a gun is designed care must be taken to see that the material from
which it is constructed is strong enough to withstand this pressure.
And not only must the gun be sufficiently strong, but it must not
be too heavy, so that you see you cannot go on forever increasing
the thickness of the walls of this tube. Besides, it is generally
acknowledged that a simple tube or cylinder cannot be made with walls
of sufficient thickness to withstand from within a _continued_ pressure
per square inch greater than the tenacity of a square-inch bar of the
same material; in other words, if the tensile strength of a metal is
only twelve tons per square inch, no gun of that metal, however thick
its walls, could withstand a pressure of twenty tons per square inch,
and the modern big guns are tested at that great a pressure. And if we
look further into this matter of pressures we find that when a gun is
fired the pressure exerts itself in two ways; it tends to burst the gun
longitudinally or down the middle, and it tends to pull the gun apart
in the direction of its length. Of course, some method of strengthening
this one-piece gun was sought after, with the result that to-day guns
are either “_built-up_” or “_wire-wound_.”

A “built-up” gun is one made of several layers, each layer being
separately constructed and then assembled together. The order of
assemblage differs somewhat with the different calibres, but the method
of assemblage is essentially the same, that is, the outside layers are
heated and shrunk on the inner ones. This question will be treated at
greater length later on.

A “wire-wound” gun is one in which the necessary additional strength
is obtained by winding wire around an inner tube of steel, each layer
being wound with a different tension of the wire; this type of gun
has found great favor with foreign manufacturers. In this country,
however, the “built-up” system is used almost exclusively, and so this
description will deal with the manufacture of a “built-up” gun.

[Illustration: HOW A BIG GUN WOULD LOOK IF YOU WERE TO CUT IT IN TWO

Sketch Showing Construction of a Modern “Built-up” Gun.

_A_, HOOP; _B_, HOOP; _C_, JACKET; _D_, TUBE; _E_, LINER; _F_, HOOP.]

A modern “built-up” gun is composed of a _liner_, a _tube_, a _jacket_
and _hoops_.

The _liner_ is in one piece and extends the entire length of the bore
and carries the “rifling” and the powder chamber.

The _tube_ is in one piece and envelops the liner for its entire
length. Formerly the _tube_ carried the “rifling” and powder chamber,
but due to the wearing out of the “rifling” with constant firing, a
liner was decided on, so that now when the “rifling” becomes worn, the
liner can be removed and a new one substituted.

The _jacket_ is usually in two pieces and is shrunk on the tube; it
extends the entire length, and its rear end is threaded in the inside
for the attachment of the “breech bushing.”

_Hoops_ are shrunk on over the jacket and in a big gun are sometimes as
many as six or seven in number.

The liner, tube, jacket and hoops are made of the finest quality of
open hearth steel, and the steel must conform to specifications set by
the government.

[Illustration:

  Photo by Bethlehem Steel Co.

This photograph shows a mould for a gun ingot under hydraulic press for
fluid compression.]

The chemical composition having been determined, the necessary elements
are weighed out and the whole charged into an open hearth furnace. When
the furnace is ready to be tapped the molten metal is run into a large
ladle, which in turn is taken by a crane to the casting pit, where the
mould is filled. The ingots for the large calibre guns run from 42-inch
to 48-inch in diameter, and after being poured they are immediately
run under a hydraulic press, where they are subjected to a pressure
of about six tons per square inch to drive out the gases, and then
lowered to about 1500 pounds pressure per square inch for a certain
length of time during the cooling. This pressure tends to make the
ingot solid, by expelling the gases, which would cause blow-holes, and
by preventing “piping” and “segregation.” When a metal cools, the top
and sides cool first, and this outer layer shrinks and pulls away from
the centre, with the result that a cavity or “pipe” would be formed,
but the hydraulic pressure forces fluid metal into this cavity and
so prevents the “pipe.” The cooling also causes the various elements
to solidify separately, and they tend to break away from the mass
and collect at the centre; this is called “segregation,” and is also
partially prevented by fluid compression. A solid ingot, however, is
obtained, and this is absolutely necessary.

After the ingot has cooled sufficiently it is “_stripped_,” that is,
it is removed from the mould, and then it is sent to the shop to have
the “discard,” or extra length, cut off. When the ingot is cast, an
extra amount of metal is poured into the mould to permit this discard,
the theory being that the poorer metal, together with gases and other
impurities, rise to the top. The government specifications require that
there shall be a 20% discard from the upper end and a 3% discard from
the lower end. The discard having been cut off, the ingot is “cored,”
that is, its centre is bored out, the diameter of the hole depending on
the size of the ingot.

[Illustration: TAKING THE BORE OF A BIG GUN

  Photo by Bethlehem Steel Co.

This photograph shows gun ingot in boring mill being cored.]

The ingot is now ready for the “forge,” and on its receipt in the forge
shop it is placed in a furnace to be heated; and here great care must
be exercised to prevent setting up any additional strains in the ingot.
When the ingot was cooling just after casting the metal tended to flow
from the centre; the interior is still in a condition of strain, and if
the cold ingot is now placed in a hot furnace, cracks are apt to form
in the centre, causing the forging to later break in service.

However, the ingot having been properly heated, it is ready for either
the forging hammer or the press. The present-day practice, though, is
to forge the ingot under a press forge, as the working of the metal
causes a certain flow, and as a certain amount of time is necessary
for this flow, the continued pressure and slow motion of the press
allows the molecules of the metal to adjust themselves more easily,
and a better and more homogeneous forged ingot is produced than if the
forging had been done with a hammer.

When forging a hollow ingot, a mandrel, merely a cylindrical steel
shaft, is placed through the hole in the ingot and the ingot forged
on the mandrel, thereby not only is the outside diameter of the ingot
decreased, but the length of the ingot is increased. The usual practice
is to continue the forging until the original thickness of the walls
of the ingot is decreased one-half and until the ingot is within two
inches of the required finished diameters. The ingot is now known as a
“forging,” and the lower end of each ingot as cast will be the breech
end of the forging that is made from it.

The next process is that of “annealing.” This consists in heating the
forging to a red heat and then allowing it to cool very slowly, and
is usually done by hauling the fires in the furnace after the correct
temperature has been attained and permitting both to cool off together.
This process is to relieve the strains set up in the metal during
forging, and further, it alters the molecular condition of the steel,
making a finer and more homogeneous forging.

[Illustration: HOW THE GUN TUBE IS TEMPERED

  Photo by Bethlehem Steel Co.

This photograph shows a gun tube ready to be lowered into oil bath for
“oil tempering.”]

After annealing, the forging is ready to go to the machine shop to
be rough bored and turned. The forging is set in a lathe, the breech
end being held by jaws on the face-plate and the muzzle end by a
“pot-centre,” a large iron ring having several radial arms screwed
through it. The lathe can now be turned and the forging centered by
screwing in or out on the jaws of the face-plate or the radial arms of
the “pot-centre.” When centered, several surfaces are turned on the
forging for “steady rests” and then all is in readiness for the turning
and boring.

In both operations of “turning” and “boring,” the work revolves while
the cutting tools are fed along. Turning is very simple and usually
several tools are cutting at the same time, but boring is a more
delicate operation, because the workman cannot see what he is doing.
And in boring, either a “hog bit” or a “packed bit” is used; a “hog
bit” is a half cylinder of cast iron fitted with one cutting tool and
used for rough cuts, while a “packed bit” is a full cylinder of wood
with metal framing and carrying two tools 180° apart and used for
finishing cuts.

The forging, having been rough machined, is now ready to receive its
heat treatment in order to give to the steel its required physical
characteristics. Every piece of steel used in gun manufacture must
conform to certain specifications as regard both its physical and
chemical characteristics. The chemical analysis was made at the time
the ingot was cast; now for the treatment of the forging, prior to the
physical test as to its tensile strength, elastic limit, elongation and
contraction.

The “tensile strength” of a metal is the unit-stress required to break
that metal into parts. If a round bar ten inches in cross-section area
will fracture under a strain of 120 tons, its tensile strength is 120 ÷
10 or 12 tons per square inch. Tensile strength is usually expressed in
pounds per square inch.

The “elastic limit” of a metal is the unit-stress required to first
produce a permanent deformation of the metal. If a bar of metal be
subjected to an increasing strain, up to a certain point that metal
will be perfectly elastic, resuming its normal shape when the strain
is removed; at the first permanent set or deformation, however,
the elastic limit of that metal has been reached. Elastic limit is
expressed in pounds per square inch.

By “elongation” is meant the increase in length in a bar when its
tensile strength is reached. If a bar 10 inches long after rupture
measures 11.8 inches, its elongation is 18%.

By “contraction” is meant the decrease in cross-section area in a bar
when its tensile strength is reached. If a bar 1 square inch in area
after rupture is only .75 of a square inch in area, its contraction is
25%.

These definitions being understood, a brief description of the heat
treatment can be taken up, because it is after this treatment that
standard bars are taken from the forgings to undergo the physical
tests. The first step consists in “tempering” or hardening the metal.
The piece to be tempered is placed in an upright position in a high
furnace and uniformly heated to the required temperature. It is then
lifted from the furnace through an opening in the top and carried by a
crane to an oil tank of suitable depth and plunged into the oil. This
rapid cooling or “tempering in oil” is facilitated by having the oil
tank surrounded by a water bath, so arranged that a supply of cold
water is constantly in circulation to carry the heat from the mass
as quickly as possible. This operation produces exceeding toughness,
increases the tensile strength and raises the elastic limit of the
metal.

Now the forging is again annealed, so as to relieve any strains set
up by tempering and to soften up the metal to the degree required by
the specifications. It also increases materially the elongation and
contraction. Great care must be exercised in the heat treatment, as the
acceptance or rejection of the forging depends upon whether or not the
test bars pass the required specifications.

The forging is now submitted for test and the test bars taken. In the
manufacture of a big gun, four test bars are taken from the breech
end and four from the muzzle end of each forging and these bars
sent to the physical laboratory. Quite an elaborate testing machine
is provided, and if the bars pass the required tests the forging is
accepted and is sent to the machine shop for finish-boring and turning.

~SEARCHING FOR POSSIBLE DEFECTS~

Frequently during finish-boring the work is examined to see that the
bit is running true, and great care must be exercised to prevent its
running out of alignment.

After finish-boring every forging is “bore-searched,” that is, the bore
is carefully examined for any cracks, flaws, streaks or discoloration.
A special instrument called a “bore-searcher” is used and consists of
a long wooden handle which has a mirror inclined at 45° at one end,
together with a light to illuminate the bore, and so shielded as to
obscure the light from the observer. (See sketch.)

[Illustration]

The bore is also inspected by the foreman after each boring, but the
final “bore-searching” is done by an inspector.

Now to measure accurately the inside diameters of long cylinders,
such as are used in gun work, a special measuring device called a
“star-gauge” is used. Its name is derived from the fact that it has
three measuring points set at 120° apart and two measurements are
taken, one [Illustration] and the other [Illustration], making a star
[Illustration]. Every forging is “star-gauged” after being finish-bored
and also the liner of the _gun_ after each assemblage operation.

~PUTTING THE PARTS OF A “BUILT-UP” GUN TOGETHER~

In preparation for the assembling of the different parts, the tube is
the forging to be finished. It is bored and turned to exact dimensions
and carefully “bore-searched” and “star-gauged.” With the data at hand
a sketch is made showing the external diameters of the liner under the
tube, due allowance being made for the shrinkage when assembling.

The liner is next bored to within .35 of an inch of the finished
diameter, and turned to the dimensions required by the sketch above.
This extra metal in the bore is left until the gun is completely
assembled and is removed in the finish-boring. The liner is then
carefully “bore-searched” and “star-gauged” and liner and tube are
ready for assembling.

The liner is now taken to the shrinking pit and carefully aligned in an
upright position with the breech end down.

The shrinking pit is merely a well of square section with room enough
to permit workmen to move freely about the gun when it is in position,
and equipped with a movable table at its bottom upon which the gun
rests. In the meantime the tube, with breech end down, is being heated
in a hot-air furnace. This furnace is a vertical cylinder built of
fire-brick and asbestos and so constructed that air which has been
passed in pipes over petroleum burners can enter at the bottom, pass
around and through the tube and out through the top to be reheated.
This service permits a uniform heat to be transmitted to the tube and
when the desired temperature has been attained the tube is lifted from
the furnace by a crane, carried to the shrinking pit and carefully
lowered over the liner. Great care must be exercised in this operation
to prevent the tube from sticking while being lowered into place.
Should it happen, the tube should be hoisted off at once, allowed to
cool, any roughing of the liner be smoothed off, the tube reheated and
a second trial made. When the tube is properly in place a cold spray
may be turned upon any particular section where it is desired the tube
should first grip the liner. The tube is then left to cool by itself,
but cold water is constantly circulating through the liner.

When the gun is sufficiently cool for handling purposes, it is hoisted
out of the shrinking pit and taken to the shop for careful measurement,
the liner being “star-gauged” to note the compression due to the
shrinking on of the tube.

The same procedure is followed in the case of the jackets and hoops,
until the entire gun is assembled. The gun is considered completely
“built-up” when the last hoop has been shrunk on and is now ready to be
finished.

The gun is now finish-bored, as .35 of an inch of metal was left in the
liner in the first boring. “Packed bits” are used and the greatest care
is exercised to keep the bit properly centered and running true. After
this step the gun is finish-turned and the powder chamber is bored.

Following this operation the gun is “bore-searched” for any defects
that may have shown up in the finish-boring and chambering, and then
carefully “star-gauged.” The gun is then ready to be “rifled.”

[Illustration: RIFLING A BIG GUN

  Photo by Bethlehem Steel Co.

This photograph shows a gun in the Rifling Machine in the process of
being rifled.]

The “rifling” of a gun consists in cutting spiral grooves in the
surface of the bore from the powder chamber to the muzzle end, and is
done from the muzzle end. Rifling is a very difficult operation, and
great care must be exercised that the cutting is uniform. The grooves
are separated by raised portions called “lands,” and after “rifling,”
these grooves and “lands” are carefully smoothed up to remove the rough
edges or burrs caused by the cutting tools of the “rifling” machine.

The necessary holes are now drilled for fitting the breech mechanism
and the breech block fitted. This operation usually takes some little
time, as quite a bit of hand work is necessary to insure a perfect fit.
The “yoke,” really another “hoop,” is now put on at the breech end and
the gun is complete.

The centre of gravity of gun and breech mechanism is now determined
by balancing on knife edges and the whole then weighed. The breech
mechanism is also weighed and the two weights marked on the rear faces
of the gun and breech mechanism.

The gun is now fitted in its “slide,” that part of the mount which
carries the trunnions and through which the gun recoils when it
is fired, and after it is adjusted, all is in readiness for the
“proof-firing” or testing of the gun.




What Is Motion?


There are practically but two things we see when we use our eyes.
One of them is matter, which is a term we apply to the things we
see, speaking of them as objects only, and the other is motion which
we observe some of the matter to possess. Some of the things we see
confuse us, if we bear in mind that everything is either matter or
motion. For instance, we see light and know it is not matter and are
confused until we understand that light is a movement of the ether
which surrounds us and is in and outside of everything. In the same way
we feel heat and may think it is matter thrown off by the fire, when it
is only another kind of motion of this same ether. When we understand
these things we see that motion is a very important and real part of
the world.

When a motion is started it will keep on going forever unless some
other force which is able to overcome the motion stops it. When a ball
is thrown in the air it would go on forever were it not for the law of
gravitation which pulls it to the earth and the friction of the air on
the ball as it goes through the air. When you stop a thrown ball you
sometimes realize that motion is a real thing because it stings your
hands. We do wonderful things with motion. Many things when you add
motion to them acquire qualities which they did not possess before. For
instance, an ordinary icicle thrown against a wooden door will break,
but if you put it into a gun and give it sufficient motion, it will go
right through the door. There is a story of how a man killed another
by using an icicle as a bullet. The icicle entered the man’s body and
killed him. Then, of course, the ice melted and no one could tell how
the man received his wound, for no trace of anything like a bullet
could be found. A piece of paper has no cutting qualities, but if you
arrange a circular or square piece of paper with a rod or stick through
the center and revolve it fast enough, you can cut many things while it
is whirling. The motion gives it the cutting qualities. You can take a
piece of strong rope and, by tying the ends together, making a circle
of it, you can make it roll down the street like a steel hoop if you
catch it just the right way and set it spinning fast enough before
starting it on its way. A steam engine has no power to pull the train
of cars until the wheels are set in motion. So we see that motion is a
very important thing in the world.

Motion is the cause of movements of all kinds, the power which takes
things from one place to another.




Is Perpetual Motion Possible?


Perpetual motion will never be possible unless some one discovers a
way to overcome the law of gravitation and also the certainty that
materials will eventually wear out. Many men have tried to make a
machine that would keep on moving forever without the application of
any power, the consumption of fuel within itself, the fall of weights
or the unwinding of a spring; such a machine would be absolutely
impossible, although many people have been fooled into investing money
in machines that appeared to have this power within themselves.




How Can an Explosion Break Windows That Are at a Distance?


An explosion is a sudden expansion of a substance like gunpowder or
some elastic fluid or other substance that has the power to explode
under certain conditions with force, and usually a loud report. Some
explosions are comparatively mild and accompanied by a very mild noise,
while others are very powerful and accompanied by a very loud noise.
When an explosion occurs, the air and everything surrounding the thing
that explodes is very much disturbed. The air surrounding the thing
that explodes is thrown back in air waves which are powerful in the
exact proportion in which the explosion is powerful. These air waves
can be so suddenly thrown back against the objects in the vicinity that
not only the windows in the buildings are broken, but often the entire
building blown away. The explosion acts in all directions at once
with equal force. A great hole may be torn in the earth beneath the
explosion. If there is anything over the explosion, that is blown away
unless its power of resistance is sufficient to withstand the power of
the explosion. Then, also, the air surrounding on all sides is forced
back against everything in its path.

Very often this air which is suddenly forced back by the power of the
explosion is thrown against houses at a distance. These houses may
be so strongly built as to be able to withstand the effect of the
explosion, but still certain parts of them, such as the windows and
the bricks of the chimney, may not be able to withstand this sudden
pressure of air against them and they are forced in. The wind from such
an explosion acts on the outside of the windows just the same as though
you stood on the outside with your hands against the windows and pushed
them in. Anything that is thrown against a window with more force than
the window glass can resist will break the window, and even slight
explosions may be so powerful as to throw the air back and away from
them with such force as to break windows at a great distance--even a
mile or more away.




Why Do Some Things Bend and Others Break?


When an outside force is applied to some objects, some of them will
bend and others break. It is due to the fact that in some things the
particles have the faculty of sticking together or hanging on to each
other, and it is very difficult to break them away from each other. In
such instances, as in the case of a wire, the article will bend when
we apply the power to it and it will not break, because the particles
which make up the wire have the faculty of hanging on to each other. A
piece of glass, however, can be broken right in two by the application
of no more force than was used to bend the wire, because the particles
which make up the glass haven’t the faculty to hang on to each other.
If you continue to bend a wire back and forth, however, at the same
point, it will finally break apart, because you eventually overcome the
ability of the particles in the wire to hang on to each other.

It all depends upon the hanging-on ability. Sometimes in undergoing
different processes an article which will ordinarily only bend will
become very brittle or breakable. A steel wire may bend but if you make
a steel wire very hard it becomes brittle. On the other hand, glass is
very brittle ordinarily, but if you make it very hot, you can bend it
into any shape you wish, and thus the glass-worker makes different
shapes to various dishes; lamp chimneys, bottles, etc., by heating
glass and then bending it. When it becomes cool again, it also becomes
brittle or breakable as before.




Why Does a Ball Bounce?


When you throw a ball against the floor in order to make it bounce the
ball gets out of shape as soon as it comes in contact with the floor.
As much of it as strikes the floor becomes perfectly flat, and because
the ball has a quality known as elasticity, which means the ability to
return to its proper shape, it returns to its shape immediately and in
doing so forces itself back into the air and that is the bounce.

Of course, the first thing we think of when we consider something
that bounces is a ball, and in most cases a rubber ball. We are more
familiar with the bouncing qualities of a rubber ball. Other balls,
like standard baseballs, are not so elastic as a rubber ball filled
with air, but a solid-rubber ball is more elastic and some golf balls
are much more elastic than a solid-rubber ball. The principle is the
same, when you drive a golf ball, excepting that when you bounce a ball
on the floor the floor does the flattening and when you drive a golf
ball, the golf club does the flattening. A baseball flies away from the
bat for the same reason. When you meet a fast-pitched ball squarely on
the nose with a good swing, it goes farther and faster than when you
hit a slow-pitched ball with an equal swing, because in the case of the
fast-pitched ball you flatten the ball out more, and it has so much
more to do to recover its proper shape that it bounces away from the
bat at much greater speed and goes much further unless caught than a
slow-pitched ball under the same circumstances.




What Makes a Ball Stop Bouncing?


A bouncing ball, when you first throw it against the wall bounces back
at you about as fast as you throw it, but if you do not catch it on the
rebound, it goes to the floor again, because the law of gravitation
which is the pulling power of the earth, pulls it down again. When it
strikes the floor it is again flattened to a certain extent and bounces
up again, but does not come back so high. It goes on striking the floor
and bouncing back into the air again each time a shorter distance,
until the force of gravity has actually overcome its tendency to bounce
back.

When you bounce a ball on the floor and it bounces up again, the motion
of the ball through the air is affected by the friction that the
contact with the air produces and this friction of the air overcomes
part of the bouncing ability in the ball also.




What Makes a Cold Glass Crack if We Put Hot Water Into It?


Hot water will not always cause a cold glass to crack, but is very apt
to, especially a thick glass. The very thin glasses will not crack. The
test tubes used by chemists are made of very thin glass, and will not
crack when hot liquids are poured into them.

When a glass cracks after you have poured a hot liquid into it, it does
so because, as soon as the hot liquid is put in, the particles of glass
which form the inside of the glass become heated and expand. They begin
to do this before the particles which form the outside of the glass
become heated, and in their efforts to expand the inside particles of
glass literally break away from the particles which form the outside,
causing the crack. The same thing happens if you put cold water into a
hot glass, excepting in this instance the inside particles of the glass
contract before the particles which form the outside of the glass have
had time to become cool and do likewise.




What Causes the Gurgle When I Pour Water from a Bottle?


The air trying to get in causes the gurgle. Air has one strong
characteristic which stands out above everything else. It wants to go
some place else all the time. When it learns of a place where there
is no air it wants to go there above all things, and goes at it with a
rush.

Now, when you turn a bottle full of water upside down, the water comes
out if the cork is out, of course, and as soon as the water starts out
the air strives to get in, and every time you hear a gurgle you know
the air is getting in. Every gurgle is a battle between the water and
the air. Sometimes the air comes and pushes the water back enough to
let it slide into the bottle; sometimes the water pushes the air back,
and thus they fight back and forth. The water always gets out and the
air always gets in. In doing so they make the gurgle.




Where Does the Part of a Stocking Go That Was Where the Hole Comes?


Perhaps this is a foolish question, but many boys and girls have been
puzzled for an answer to it. When you put your stockings on they have
no holes in the feet, and at night, when you take them off, there are
often quite large holes in them. The answer is the same as in the case
of the lead in the lead-pencil. The lead in the pencil wears away. You
can see it wear away because that is what makes the marks.

When a hole is coming into your stocking, the stocking on your foot
is being rubbed between your foot and something else (probably some
part of your shoe) and this constant rubbing will wear through the
yarns with which the stocking is knitted. Of course, the yarns in
the stocking are stretched somewhat when it is on your foot and the
rubbing finally cuts through the threads and releases the tension of
the threads of yarn, so that not always is as much stocking lost as
the size of the hole. But, if you were to look carefully at your foot
and inside your shoe, when you first take the stocking off and see the
hole, you would find little particles of yarn all about.




Why Do Coats Have Buttons On the Sleeves?


The practice of putting buttons on coat sleeves, which serve no useful
purpose at all and do not add to the beauty of the coat, is a relic of
very old days.

There was a time when people did not use handkerchiefs, and it was
common practice for men to wipe their noses on their sleeves. They had
coats also in those days, but they did not have buttons on the sleeves.
One of the old kings finally developed the idea of dressing his
soldiers in fancy uniforms and, as he sat in his palace and reviewed
his troops, he noticed many of them using the sleeves of their coats as
handkerchiefs. He immediately issued a decree that all sleeves should
have a row of buttons sewed on them, but at a point directly opposite
to where they are now on the sleeves. This was done to remind the
soldiers that the sleeves of their beautiful uniforms were not to be
used as handkerchiefs, and those who attempted to draw their sleeves in
front of the nose were quickly reminded of the decree by the buttons
which scratched them. And so the buttons really had a quite useful
purpose at one time, and so also all sleeves had buttons sewed on to
them at this place. Later on, however, when the unsightly practice had
been cured and people had learned to use handkerchiefs, the buttons
remained as a decoration, but their former purpose was lost sight of.
Then some tailor or leader of fashion had the buttons set on the under
side of the sleeves for a change, and it became the fashion to have
them there, and the tailors have been sewing them there ever since.




Why Has a Long Coat Buttons on the Back?


The buttons on the back of a long coat, i. e., one with skirts, had a
more sensible reason originally. At one time the skirts of such coats
were made very long, and when the wearer moved quickly the tails of
the coat flapped about the legs and interfered with progress. So an
ingenious gentleman had buttons sewed on to the back and buttonholes
made in the corner of his coat-tails. Then when he was in a hurry he
simply buttoned up his skirts and went his way comfortably.

[Illustration: TELEPHONE DISPLAY BOARD

Showing in outline the apparatus necessary to complete the simplest
kind of a telephone call--to a number in the same exchange]




The Story in the Telephone


~WHAT HAPPENS WHEN WE TELEPHONE~

Mrs. Smith, at “Subscriber’s Station No. 1,” desires to telephone
to Mrs. Jones at “Subscriber’s Station No. 2.” When she lifts her
receiver, the movement causes a tiny white light to appear instantly on
the switchboard at the Central Office. Directly beneath this light is
another and larger lamp, which glows in a way to attract the operator’s
attention immediately.

The operator inserts a “plug” in a little hole on the switchboard
called a “jack,” directly above the tiny light which appeared when Mrs.
Smith lifted the receiver. This connects her to Mrs. Smith’s line. Then
she pushes a listening key on the board, connecting her telephone set
to the line. “Number, please?” she calls.

Mrs. Smith gives the number; the operator repeats it to be sure there
is no mistake, places another “plug” in a “jack” corresponding to the
number of Mrs. Jones’ telephone and makes the connection.

Each subscriber’s telephone has a particular signal on the switchboard
to which it is connected by a pair of wires. Mrs. Smith’s wires run
from her instrument to the nearest “cable terminal,” a gathering point
for the wires of various telephones in her neighborhood. Here they form
part of a group of wires going to the Central Office. These groups,
called cables, are made up of from 50 to 600 pairs of wires, according
to the telephone needs of the district the “terminal” serves.

When the wires reach the Central Office they pass through the “cable
vault” to the “main distributing frame,” which is the Central Office
terminal of the cable.

When the wires come to this frame they are in numbered order in the
cable. Subscribers living next door to Mrs. Smith may have entirely
different call numbers and yet use consecutive wires. It is the task
of the main frame to redistribute these wires, so that they will be
arranged according to their call numbers and to make it possible to
connect Mrs. Smith’s line with the line of any other subscriber with
the least possible delay. This frame has two parts: the “vertical
side” and the “horizontal side.” Before the wires are redistributed
they are taken to pairs of springs equipped with devices for protecting
the lines against outside currents.

[Illustration: ASKING FOR A NUMBER]

After leaving the main frame they are taken to the “intermediate
distributing frame,” the central connecting point for various branches
of the lines going to the switchboard, signaling and other apparatus.
From the “horizontal side” of this frame, wires go to the switchboard,
where they terminate in little holes known as “multiple jacks.” They
also connect with the line and position message registers, where the
calls from each Line and the calls handled at each operator’s position
at the switchboard are recorded. The “multiple jacks” are additional
terminals placed at necessary intervals throughout the switchboard,
where they can be used by operators to make connections with any other
line on the board.

From the “vertical side” of the intermediate frame Mrs. Smith’s wires
reach the “line and cut-off relay,” an electrically controlled switch
which turns on the light signal that appears on the switchboard
when she lifts the receiver from the hook. This “line relay” also
extinguishes the light when the operator makes the connection, or when
Mrs. Smith returns the receiver to the hook.

[Illustration: A TYPICAL POLE LINE, WITH CROSS ARMS, IN THE COUNTRY]

The swift moving electric current that was set in motion when Mrs.
Smith began the call, instantaneously passes through all these devices
for safeguarding and protecting the subscriber’s telephone service. The
light announcing Mrs. Smith’s desire to make a call is called the “line
lamp,” and is flashing on the switchboard. Directly beneath it is the
“pilot lamp,” which glows whenever any “line lamp” lights. With the
“line lamp” is a “jack” or terminal, where connection can be made with
Mrs. Smith’s line. This is the “answering jack.”

[Illustration: THE CABLE VAULT INTO WHICH THE CABLES PASS WHEN THEY
ENTER THE EXCHANGE AND FROM WHICH THEY ARE LED UPWARD TO THE MAIN
DISTRIBUTING FRAME]

When the operator sees the flashing signal of Mrs. Smith’s “line lamp,”
she inserts one end of a pair of “connecting cords,” which are on
the board before her, in the “answering jack” for Mrs. Smith’s line.
These “connecting cords” are flexible conductors that put the wires
of subscribers in electrical connection. Then she pushes forward the
“operator’s key” directly in front of her and is connected with Mrs.
Smith’s line.

The operator ascertains the number wanted and places the other
“connecting cord” in the “jack” corresponding to Mrs. Jones’ line. If
she finds she cannot herself connect with Mrs. Jones’ “jack,” because
it is on another part of the board out of her reach, she makes a
connection with another operator who can reach Mrs. Jones’ line. The
second operator then makes the connection with Mrs. Jones’ “multiple
jack” and places her line in connection with Mrs. Smith’s line at the
first operator’s position. At the same time the first operator pushes
the operator’s key back, thus ringing Mrs. Jones’ bell.

“Supervisory lamps” on the board before her, connected with the
“connecting cords,” tell the operator when Mrs. Jones answers the
summons. They flash when the connection is made and one goes out just
as soon as Mrs. Jones takes the receiver from the hook to answer.
If one of these lamps flashes and dies out alternately it tells the
operator that either Mrs. Smith or Mrs. Jones is trying to attract her
attention and she connects herself and ascertains the party’s wishes.
When both subscribers “hang up,” both lights flash to indicate the
end of the conversation. The operator then disconnects the cords from
the subscribers’ “jacks” and presses the “message register” button
recording the call against Mrs. Smith.

[Illustration: ROUTINE OF A TELEPHONE CALL

The subscriber, after looking up in the directory the desired number,
takes the telephone off the hook, which causes a tiny electric light to
glow in front of the operator assigned to answer his calls. (In some
exchanges equipped with a magneto system, a drop is released by the
turning of a crank.)]

[Illustration: The arrow indicates the light as it appears on the
switchboard. Each operator can connect a caller with any subscriber
in that exchange, but she is assigned to answer the calls of only a
limited number of subscribers whose signals are these lights showing at
her particular position.]

[Illustration: She takes up a brass-tipped cord, inserts the tip,
or “plug,” into the hole, or “jack,” just above the light, at the
same time throwing a key with the other hand in order to switch her
transmitter line into direct communication with the caller, and says:
“Number?”]

[Illustration: The caller replies by giving the name of the exchange
and the number he wants, as for example, “Main 1268.” The operator
repeats the number, “One-two-six-eight,” pronouncing each digit with
clear articulation, to insure its correctness, and, if it be from a
subscriber in the Main Exchange, she--]

[Illustration: Takes up the cord which is the team mate, or “pair,” of
the one with which she answered the caller, locates the jack numbered
1268, and “tests” the line by tapping the tip of the plug for a moment
on the sleeve of the “jack” to ascertain if the line is “busy.” If no
click sounds in her ear she--]

[Illustration: Pushes in the plug and with her other hand operates a
key on the desk. The first action connects the line of the subscriber
called; the second rings his bell. When either party hangs up his
receiver, a light glows on the switchboard desk, showing the operator
that the conversation is ended.]

[Illustration: THE CENTRAL TERMINAL OF YOUR TELEPHONE

A MULTIPLE SWITCHBOARD]

[Illustration: THE BACK OF A MULTIPLE SWITCHBOARD]

[Illustration: THE BIRTHPLACE OF THE TELEPHONE, 109 COURT STREET, BOSTON

On the top floor of this building, in 1875, Prof. Bell carried on his
experiments and first succeeded in transmitting speech by electricity]


How the Telephone Came to Be.

It is hard to realize that there was once a time, not so very many
years ago, when the telephone was regarded as a scientific toy and
hardly anyone could be found willing to invest any money in the
development of the telephone business.

[Illustration: ALEXANDER GRAHAM BELL IN 1876]

[Illustration: THOMAS A. WATSON IN 1874]

The story of Professor Alexander Graham Bell’s wonderful invention is
full of romantic interest and the early days of its exploitation were
replete with dramatic incidents.

~THE MEN WHO MADE THE TELEPHONE~

Young Bell had come to America in 1870 in search of health, the family
settling at Brantford, Canada. He numbered among his forebears many
distinguished professional men. For three generations the Bells had
taught the laws of speech in the universities of Edinburgh, Dublin and
London. He himself was an accomplished elocutionist and an expert in
vocal physiology.

During the year spent in Canada in regaining his health, Bell taught
his father’s method of visible speech to a tribe of Mohawk Indians and
began to think about the “harmonic telegraph.”

In 1871 young Alexander Bell accepted an offer from the Boston Board
of Education to teach the “visible speech” method in a school for deaf
mutes in that city.

For two years he devoted himself to the work with great success. He was
appointed a professor in the Boston University and opened a school of
“Vocal Physiology” which was at once successful.

He might have continued his career as a teacher had it not been that
his active brain still clung to the “harmonic telegraph” idea and his
inventive genius demanded an outlet.

[Illustration: PROF. BELL’S VIBRATING REED]

So we find him in 1874 working out his idea of the “harmonic
telegraph,” the perfection of which meant a fortune to the young
inventor. That he never realized his goal was due to the fact that
while experimenting, he made a discovery which led to a far greater
invention and one that was fraught with more benefit to mankind than
the “harmonic telegraph” could ever have been.

It was while working with his faithful man Friday, Thomas A. Watson,
in the dingy little workrooms on Court Street, Boston, that Bell got
the inspiration which made him turn from the “harmonic telegraph” to
devote himself to the invention which was destined to make his name
famous--the speaking telephone.

~THE FIRST SOUND OVER A WIRE~

Mr. Watson has dramatically described the incident as follows:

“On the afternoon of June 2, 1875, we were hard at work on the same
old job, testing some modification of the instruments. Things were
badly out of tune that afternoon in that hot garret, not only the
instruments, but, I fancy, my enthusiasm and my temper, though Bell
was as energetic as ever. I had charge of the transmitters, as usual,
setting them squealing one after the other, while Bell was retuning
the receiver springs one by one, pressing them against his ear as I
have described. One of the transmitter springs I was attending to
stopped vibrating and I plucked it to start it again. It didn’t start
and I kept on plucking it, when suddenly I heard a shout from Bell in
the next room, and then out he came with a rush, demanding, ‘What did
you do then? Don’t change anything. Let me see!’ I showed him. It was
very simple. The make-and-break points of the transmitter spring I was
trying to start had become welded together, so that when I snapped the
spring the circuit had remained unbroken while that strip of magnetized
steel by its vibration over the pole of its magnet, was generating that
marvelous conception of Bell’s--a current of electricity that varied in
intensity precisely as the air was varying in density within hearing
distance of that spring. That undulatory current had passed through
the connecting wire to the distant receiver which, fortunately, was
a mechanism that could transform that current back into an extremely
faint echo of the sound of the vibrating spring that had generated it,
but what was still more fortunate, the right man had that mechanism
at his ear during that fleeting moment, and instantly recognized
the transcendent importance of that faint sound thus electrically
transmitted. The shout I heard and his excited rush into my room were
the result of that recognition. The speaking telephone was born at
that moment. Bell knew perfectly well that the mechanism that could
transmit all the complex vibrations of one sound could do the same for
any sound, even that of speech. That experiment showed him that the
complex apparatus he had thought would be needed to accomplish that
long-dreamed result was not at all necessary, for here was an extremely
simple mechanism operating in a perfectly obvious way, that could do
it perfectly. All the experimenting that followed that discovery, up
to the time the telephone was put into practical use, was largely a
matter of working out the details. We spent a few hours verifying the
discovery, repeating it with all the differently tuned springs we had,
and before we parted that night Bell gave me directions for making the
first electric speaking telephone. I was to mount a small drumhead
of gold-beater’s skin over one of the receivers, join the center of
the drumhead to the free end of the receiving spring and arrange a
mouthpiece over the drumhead to talk into. His idea was to force the
steel spring to follow the vocal vibrations and generate a current of
electricity that would vary in intensity as the air varies in density
during the utterance of speech sounds. I followed these directions and
had the instrument ready for its trial the very next day. I rushed it,
for Bell’s excitement and enthusiasm over the discovery had aroused
mine again, which had been sadly dampened during those last few weeks
by the meagre results of the harmonic experiments. I made every part of
that first telephone myself, but I didn’t realize while I was working
on it what a tremendously important piece of work I was doing.

[Illustration: WHAT THE FIRST TELEPHONE LOOKED LIKE

ALEXANDER GRAHAM BELL’S FIRST TELEPHONE]


The First Telephone Line.

“The two rooms in the attic were too near together for the test, as
our voices would be heard through the air, so I ran a wire especially
for the trial from one of the rooms in the attic down two flights to
the third floor where Williams’ main shop was, ending it near my work
bench at the back of the building. That was the first telephone line.
You can well imagine that both our hearts were beating above the normal
rate while we were getting ready for the trial of the new instrument
that evening. I got more satisfaction from the experiment than Mr. Bell
did, for shout my best I could not make him hear me, but I could hear
his voice and almost catch the words. I rushed upstairs and told him
what I had heard. It was enough to show him that he was on the right
track, and before he left that night he gave me directions for several
improvements in the telephones I was to have ready for the next trial.”

Then followed many heart-breaking months of experimenting and it was
not until the following March that the telephone was able to transmit
a complete, intelligible sentence.

[Illustration: TELEPHONE APPARATUS PATENTED IN 1876 BY PROF. BELL,
PHOTOGRAPHED FROM THE ORIGINAL INSTRUMENTS IN THE PATENT OFFICE AT
WASHINGTON]

On February 14, 1876, Professor Bell filed at Washington his
application for patents covering the telephone which he described as
“an improvement in telegraphy” and on March 3, of the same year, the
patent was allowed.

That was the year of the Centennial Exposition at Philadelphia and
Professor Bell had a working model of the telephone on exhibition.
Tucked away in an obscure corner it had attracted but little attention,
until on June 25th an incident occurred which had a tremendous effect
in giving to the new invention just the sort of publicity it needed.

Professor Bell himself describes the incident in the following
interesting manner:

“Mr. Hubbard and Mr. Saunders, who were financially interested in the
telephone, wanted this instrument to be exhibited at the Centennial
Exhibition. In those days--and I must say even up to the present time
I am afraid to say it is true--I was not very much alive to commercial
matters, not being a business man myself. I had a school for vocal
physiology in Boston. I was right in the midst of examinations.

“I went down to Philadelphia, growling all the time at this
interruption to my professional work, and I appeared in Philadelphia
on Sunday, the 25th. I was an unknown man and looked around upon the
celebrities who were judges there, and trotted around after the judges
at the exhibition while they examined this exhibit and that exhibit. My
exhibit came last. Before they got to that it was announced that the
judges were too tired to make any further examinations that day and
that the exhibit could be examined another day. That meant that the
telephone would not be seen, for I was not going to come back another
day. I was going right back to Boston.

~HOW AN EMPEROR SAVED THE TELEPHONE~

“And that was the way the matter stood--when suddenly there was one man
among the judges who happened to remember me by sight. That was no less
a person than His Majesty Dom Pedro, the Emperor of Brazil. I had shown
him what we had been doing in teaching speech to the deaf in Boston,
had taken him around to the City School for the Deaf and shown him the
means of teaching speech, and when he saw me there he remembered me
and came over and shook hands and said: ‘Mr. Bell, how are the deaf
mutes of Boston?’ I said they were very well and told him that the next
exhibit on the program was my exhibit. ‘Come along,’ he said, and he
took my arm and walked off with me--and, of course, where an Emperor
led the way the other judges followed. And the telephone exhibit was
saved.

[Illustration: THE FIRST TELEPHONE SWITCHBOARD USED. EIGHT SUBSCRIBERS.]


An Emperor Wonders.

“Well, I cannot tell very much about that exhibit, although it was
the pivotal point on which the whole telephone turned in those days.
If I had not had that exhibition there it is very doubtful what the
condition of the telephone would be today. But the Emperor of Brazil
was the first one to bring that situation about at that time. I went
off to my transmitting instrument in another part of the building, and
a little iron box receiver was placed at the ear of the Emperor. I told
him to hold it to his ear, and then I heard afterward what happened. I
was not present at that end of the line. I went to the other end and
was reciting, ‘To be or not to be, that is the question,’ and so on,
keeping up a continuous talk.”

“I heard afterward from my friend, Mr. William Hubbard, that the
Emperor held it up in a very indifferent way to his ear, and then
suddenly started and said, ‘My God! it speaks!’ And he put it down; and
then Sir William Thomson took it up and one after another in the crowd
took it up and listened. I was in another part of the building shouting
away to the membrane telephone that was the transmitter. Suddenly I
heard a noise of people stamping along very heavily, approaching, and
there was Dom Pedro, rushing along at a very un-Emperor-like gait,
followed by Sir William Thomson and a number of others, to see what I
was doing at the other end. They were very much interested. But I had
to go back to Boston and couldn’t wait any longer. I went that very
night.”

“Now, it so happened there, that, although the judges had heard speech
emitted by the steel disc armature of this receiving instrument, they
were not quite convinced that it was electrically produced. Some one
had whispered a suspicion that it was simply the case of the thread
telegraph, the lovers’ telegraph, as it was known in those days, and
that the sound had been mechanically transmitted along the line from
one instrument to the other. Of course, I did not know about it at that
time; but when the judges asked permission to remove the apparatus
from that location I said, ‘Certainly, do anything you like with it.’
But I could not remain to look after it; they had to look after it
themselves.”

“My friend, Mr. William Hubbard, who had kindly come up from Boston
to help me on this celebrated Sunday, June 25, said he would do his
best to help them out, although he was not an electrician. He knew
nothing whatever about the apparatus, beyond being in my laboratory
occasionally, knowing me well. But he undertook to remove this
apparatus and set up the line under the direction of the judges
themselves. So they had an opportunity finally of satisfying themselves
that speech had really been electrically reproduced.”

“Sir William Thomson’s announcement was made to the world in England,
before the British Association, and the world believed--and from that
time dates the popular interest in the telephone.”

In October, 1876, the first outdoor demonstration, in which
conversation was carried on over a private telegraph wire, borrowed for
the occasion, took place between Boston and Cambridge, a distance of
two miles.

In April, 1877, the first telephone line was installed between Boston
and Somerville.

A month later an enterprising Boston man put up a crude switchboard
in his office and connected up five banks, using the system for
telephoning in the day-time and as a protection against burglars at
night. This was the beginning of the exchange system, all previous
telephoning having been between two parties on the same circuit.

~NINE MILLION TELEPHONES IN U. S.~

Soon after exchanges sprang up in several cities, and by August of that
year there were 778 Bell telephones in use. From this modest beginning
the telephone has grown until on January 1, 1914, there were 13,500,000
telephones in the world, nearly 9,000,000, or over 64 per cent being in
the United States.

[Illustration: MODERN DISTRIBUTING FRAME

When the wires come to this frame they are in numbered order in the
cable. The main frame redistributes these wires so that they are
arranged according to their call numbers, making it possible to connect
any wire with any other wire anywhere that telephone service is
installed.]

[Illustration: HOW THE WIRES ARE PUT UNDERGROUND

Breaking Up the Asphalt Pavement. First Step in Laying an Underground
Cable.]

[Illustration: Laying Multiple Duct Tile Subway Through Which the
Cables Will Run.]

[Illustration: Feeding Cable Into Duct as It is Being Pulled Through
Subway from the Other End.]

[Illustration: A CABLE TROUBLE]

The use of the telephone instrument is common, but it affords no idea
of the magnitude of the mechanical equipment by which it is made
effective.

~UNSEEN FORCES BEHIND YOUR TELEPHONE~

To give you some conception of the great number of persons and the
enormous quantity of materials required to maintain an always-efficient
service, various comparisons are here presented.

[Illustration: TELEPHONES. Enough to string around Lake Erie--8,000,000,
which, with equipment, cost at the factory $45,000,000.]

[Illustration: WIRE. Enough to coil around the earth 621
times--15,460,000 miles of it, worth about $100,000,000, including
260,000 tons of copper, worth $88,000,000.]

[Illustration: LEAD AND TIN. Enough to load 6,600 coal cars--being
659,960,000 pounds, worth more than $37,000,000.]

[Illustration: CONDUITS. Enough to go five times through the earth from
pole to pole--225,778,000 feet, worth in the warehouse $9,000,000.]

[Illustration: POLES. Enough to build a stockade around
California--12,480,000 of them, worth in the lumber yard about
$40,000,000.]

[Illustration: SWITCHBOARDS. In a line would extend thirty-six
miles--55,000 of them, which cost, unassembled, $90,000,000.]

[Illustration: BUILDINGS. Sufficient to house a city of 150,000--more
than a thousand buildings, which, unfurnished, and without land, cost
$44,000,000.]

[Illustration: PEOPLE. Equal in numbers to the entire population of
Wyoming--150,000 employes, not including those of connecting companies.]

The poles are set all over this country, and strung with wires and
cables; the conduits are buried under the great cities; the telephones
are installed in separate homes and offices; the switchboards housed,
connected and supplemented with other machinery, and the whole system
kept in running order so that each subscriber may talk at any time,
anywhere.




Where Does Sound Come From?


Somebody or something causes every sound we hear. Sounds are the result
of disturbances in the air. Sound is produced by waves in the air. The
buzz of the bumble-bee is caused by the quick movement of his wings
in the air. The wings themselves do not make the sound, but their
motion causes waves or vibrations in the air which produce the sound
of buzzing. Every motion made by anybody or anything produces waves in
the air just like the waves you see in the water--a big movement makes
a big wave and a tiny movement a tiny wave. When you clap your hands
you make a disturbance in the air which causes a sound--the harder you
clap the louder the sound. You can hear this sound and anybody else
near can hear it. If there were no air about us, however, we would hear
no sound, even if we could live in such a condition of things, for it
is the air waves produced striking against the drum of our ears that
enable us to discern sounds. When we talk we make air waves also and
thus produce sound. If you were deaf, and talked, you could not hear
any sound, because even when there are air waves they must still strike
against a sounding board in order to be recognized as sound--and the
drum of our ear is our sounding board for hearing sounds.

When the air waves produced are regular we call the sound musical, and
when they are irregular we call it noise. Some people can make musical
sounds when they sing, while others cannot.

If you take a piece of thin wire and stretch it tightly, fastening it
at both ends, and then pull it with your finger and let go, you will
hear a musical sound, because the vibrations produced will be regular
and will continue for some time. If you shorten the distance on the
wire where it is fastened at both ends and pull it as before, the
sound produced will be in a higher key. If you take a guitar and snap
the big G string you will produce the bass note of G. If the other
G string (the smaller one) is in tune (if you watch the smaller one
closely while you strike the larger one) you will notice the smaller
one vibrate also. Sound waves of the same tone, although in different
octaves, produce the same sounds, although in different keys.

This is the principle on which the piano is made to produce music.
Inside the piano are wires of different lengths and the keys of the
piano are arranged to operate certain little hammers, each of which
strikes a certain wire. Every time you strike a piano key you cause one
of the little hammers to hit its wire--the wire then makes vibrations
which cause air waves. The air waves strike against the sounding board
which is located behind the wires, and being thrown back into the air,
strike against the drum of our ears, and we can hear the note.




Why Can We Make Sounds With Our Throats?


The sounds we make when we talk are produced in exactly the same way
with the exception of the little hammers. In our throats are two cords
which we call our vocal cords. When we talk we cause these cords to
vibrate and thus we make the sounds of our voices. The most wonderful
part of this voice of ours is that with only two vocal cords or wires,
we can produce practically all the notes that can be made with a piano,
which has a wire or cord for every note, excepting that we cannot make
so many at one time. The human throat is so wonderfully constructed
that we can lengthen or shorten our vocal cords at will and produce,
with two strings, in our throats as many notes as it takes the piano
many more strings to produce.




Why Does the Sound Stop When We Touch a Gong that Has Been Sounded?


When we touch the gong we stop the sound waves which the gong gives
off when it is struck. These sound waves continue after the gong has
been struck in continuous vibrations until something stops them. When
you touch the vibrating gong, you stop its vibrating. If you only
touch your finger to the vibrating gong you can feel the vibrations
which cause a little tickling sensation. Naturally when you stop these
vibrations you stop the air waves which the vibrations cause, and thus
also the sound of these air waves striking your ear are stopped and the
sound ceases.




How Can Sound Come Through a Thick Wall?


A sound will come through a thick or thin wall only if the wall is a
good conductor of sound. Some things are good conductors of sound and
others are not, just as some things are good conductors of electricity
and others are not. If a wall is built of materials all of which are
good conductors of sound, the sound will come through it no matter how
thick. Wood is an especially good conductor of sound. It is even better
than air. You can stand at one end of a long log and have another
person at the other end hold up his watch in the air, and you cannot
hear the watch tick, but if the watch is “going” as we say, and you ask
the person holding it to put the watch against his end of the log, and
you then put your ear to the other end, you can hear the watch ticking
almost as well as if you had it to your own ear. In like manner you can
hear the scratching of a pin at the other end of the log. When you put
your ear against a telegraph pole you can hear the hum of the wires
while you cannot hear it through the air. All sound is produced by
sound waves and many solids are better conductors of sound waves than
the air.

Sound waves, however, will sometimes not be heard as plainly through a
wall, because of the fact that the wall may be made of materials which
are not equally good conductors of sound. When a sound wave strikes a
poor conductor it loses some of its power and the sound, although it
may be heard through the wall, will be fainter.




What Is Meant by Deadening a Floor or a Wall?


By deadening a floor, for instance, we mean inserting between the
ceiling of the room below and the floor above, or in the instance of a
deadened wall, between the two sides of the wall, some substance like
felt, paper or other non-conductor of sound, which will prevent the
sound waves from passing through. This deadens them to the passing of
sound or makes them sound-proof.




What Makes the Sounds Like Waves in a Sea Shell?


The sounds we hear when we hold a sea shell to the ear are not really
the sound of the sea waves. We have come to imagine that they are
because they sound like the waves of the sea, and knowledge that the
shell originally came from the sea helps us to this conclusion very
easily.




What Are the Sounds We Hear in a Shell?


The sounds we hear in the sea shell are really air waves or sounds made
by air waves, because all sounds are produced by air waves.

The reason you can hear these sounds in a sea shell is because the
shell is so constructed that it forms a natural sounding box. The
wooden part of a guitar, zither or violin is a sounding box. They have
the faculty of picking up sounds and making them stronger. We call them
“resonators,” because they make sounds resound. The construction of a
sea shell makes an almost perfect resonator. A perfect resonator will
pick up sounds which the human ear cannot hear at all and magnify them
so that if you hold a resonator to the ear you can hear sounds you
could not otherwise hear. Ear trumpets for the deaf are built upon this
principle.

Sometimes when you, with your ear alone, think something is absolutely
quiet, you can pick up a sea shell and hear sounds in it. But the sea
shell will magnify any sound that reaches it.

It would be possible, of course, to take a sea shell to a place where
it would be absolutely quiet and then there would be no sounds.

There are such places, but very few of them. A room can be built which
is absolutely sound proof.

[Illustration: SIBERIAN LAMBS IN SOUTH DAKOTA]




The Story in a Suit of Clothes


Where Does Wool Come From?

We could not write the story of a suit of clothes without dealing
largely with the sheep, for it is only from the wool of the sheep
that the best, warmest and most lasting garment can be made. In order
that we may properly understand the development of the great wool and
clothing industry in America we must supply a brief history of our
sheep industry, for the sheep must always come before the clothing.


Who Brought the First Sheep to America?

The sheep is not a native of America, but it came here with the first
white men. History records that Columbus on his way to this country
stopped at the Canary Islands to take on stores. Among other things
he loaded a number of sheep, some of which were later landed on the
new continent. What became of this early importation history does not
record, but it is probable that most, if not all, of them perished from
the attack of wild animals or at the hands of the natives. However,
when settlers began pouring into the new world many of them brought
along their sheep, so that from the earliest colonial days the sheep
constituted our most numerous domestic animals. This, indeed, was
necessary, for if the colonist was to survive the rigor of our climate
he must have an abundant supply of woolen clothing. In those days
clothing materials were limited to wool, flax and the skins of animals,
and, as may be supposed, wools were in very great demand. England and
most European countries prohibited the exportation of wool, in order to
increase the demand for the clothing which she manufactured. However,
as our new colonist had ample time and but little money, he desired
to make his own clothing rather than send such funds as he had to the
mother country. Therefore, the new settler, as a matter of necessity,
was forced to increase the domestic supply of wools.


Who Started to Make Clothing from Wool in America?

Early records reveal that shortly after the year 1600 many of the
colonies passed laws for the purpose of encouraging the sheep industry.
In fact, some of them went so far as to prohibit the transportation
of sheep or wool from one colony to another. However, our new sheep
industry prospered, and well it should, for it had the backing of every
prominent patriot of the early days. Washington, Jefferson, Madison,
and Franklin all were enthusiastic advocates of sheep husbandry, for
they knew that unless a people had a large domestic supply of wool they
could not long remain independent or hope to gain independence from
foreign countries. In fact, at one time Washington owned as many as one
thousand sheep, and if he lived in the present day he would be regarded
as a sheep baron. Wool, next to food, is the most vital necessity of a
people, for when wars come wool becomes a contraband, and all foreign
supplies are shut off. Thus, in stimulating a domestic wool supply the
great wisdom of our early patriots was vindicated with the coming of
the Revolutionary War. When that great struggle came our foreign wool
supply was shut off, but on account of the foresight of these patriots
in encouraging home production, our colonists had a supply ample for
most of their needs.

We not only had the wool, but the housewife had learned the art of
manufacturing wool into clothing by means of the spinning wheel, so
that when our soldiers went forth in that great struggle, which was to
bring to us independence, they were clad in garments made of American
grown wool and manufactured by the good housewife during her hours of
leisure.

When affairs became tranquil, following the close of the Revolution,
settlement, which had largely been confined to the Atlantic coast,
pushed westward farther and farther into the wilderness. Each of
these settlers took with him his supply of sheep, for the purpose of
furnishing wool for clothing and meat for food. In the early days
wool was not grown for the purpose of sale, but to be used entirely
by the family of the producer. However, when settlement reached the
Mississippi River, conditions changed. Wool manufacturing had then been
established in the land, and it became customary to raise wool to sell
to these manufacturers, who had located along the Atlantic seaboard.


Why Does the Sheep Precede the Plow in Civilizing a Country?

In all countries the sheep has been the pioneer of civilization. They
have settled and developed practically all new lands. In fact, so
firmly established has been this rule that it seems almost necessary
that the sheep should precede the plow, and thus prepare land for
agriculture. The reason for this is that the sheep is a tractable
animal and depends on man to guide its every step. It can endure
hardships that would destroy other forms of animal life. However, the
maintenance of a sheep industry requires an abundance of labor, and in
this way settlement always follows the sheep. So has it been in foreign
countries, and so was it in this country.


Where Does Most of Our Wool Come From?

Sheep came into our western states early in the seventies, at a time
when these states were thinly settled, but following the sheep came the
labor incident to its care, and thus the railroads, stores, cities and
schoolhouses found their way into the land. Originally all of our sheep
industry was east of the Mississippi River. Then for a time it was east
of the Missouri River. To-day west of the Missouri River we have about
23,000,000 aged sheep, or more than one-half of the total in the United
States. In the pioneer days the western sheep skirmished on the range
for most of the food that it obtained. To-day conditions are different,
and, while the sheep is on the range for a short time each year, it
spends its summer in the National Forest, for which grazing a fee is
paid to the Federal Government. Its winters are spent largely around
the hay-stack of the farmer, and about fifty to sixty cents’ worth of
hay is fed to each sheep in the West each winter. With the coming of
spring the western sheep are divided into bands of about 1500, and each
two bands are placed in care of three caretakers, who care for and
protect the sheep either on the deeded land of the owner or on the land
rented from the Federal Government.

[Illustration: SHEEP COMING OUT OF FOREST]


How Much Wool Does America Produce Yearly?

So much for the history of our sheep. A few words now about wool. The
total wool crop of the United States is approximately 300,000,000
pounds per year. The value of this crop is around $60,000,000 annually.


How Do We Get the Wool Off the Sheep?

With the coming of spring our sheep are driven to large central plants,
where they are shorn by the use of machines driven by electricity or
steam power. One man shears about one hundred and fifty sheep per day.
For this he receives eight cents per head. When the wool is taken off
the sheep it is gathered up and carefully tied with string made of
paper. The tied fleece is then dropped into an elevator, and is carried
up about ten feet, where it is dropped into a large sack about three
feet in diameter and seven feet long. In this sack there is always a
wool tramper, who keeps tramping the fleeces down, so that about forty
fleeces are finally put into each sack, making the weight of the sack
approximately three hundred pounds. As these sacks are filled they are
carefully stored in a dry shed, and, when shearing is completed, are
hauled to the railroad station and shipped to the great wool centers of
Boston or Philadelphia. While the bulk of the wool in the United States
is produced west of the Missouri River, that territory manufactures
very little wool. So the western sheepman, who is thus forced to grow
his wool in the western states, pays about two cents a pound freight on
it back to the eastern market, where it is sold and later manufactured
into cloth. A part of this same clothing is then shipped west, to be
sold to the very man, in some instances, who produced the wool out of
which it is made.

American wool, taken as a whole, is the best wool grown in the world.
It is not as soft as some Australian wool, but all of it possesses
a greater strength than foreign wools, and it has long since been
determined that clothing made of American wool will give better service
than that made of foreign wool. Of the wool used in the United States
for the manufacturing of clothing we produce about 70 per cent and
import about 30 per cent.


How Much Does the Wool In a Suit of Clothes Cost?

It is customary for the person who buys clothing made of wool to
believe that the value of the wool in the cloth is what makes the
clothing seem expensive. However, if we take a man’s suit made of
medium-weight cloth, such as is worn in November, we find that it
requires about nine pounds of average wool to make the suit. For this
wool the sheepman receives an average of seventeen cents per pound, so
that out of the entire suit the man who produces the material out of
which the suit is made receives a total of $1.53. A suit such as is
here described would be of all wool and free from shoddy or any wool
substitute. It would be a suit that would be sold by the storekeeper
at $25.00, and if you had it made by the tailor he would charge you
$35.00. Yet the wool-grower furnished all the material out of which
the suit was made, and received as his share but $1.53. Thus it will
be clear to the person who buys clothing and reads these lines that no
longer can the blame for the high cost of clothing be laid at the door
of the wool-grower.

While the wool-using population of the world is increasing very
rapidly, the number of wool-producing sheep in the world is decreasing.
Ordinarily this would mean that a point would be reached where the
supply of wool would be totally inadequate to meet the needs of the
public. However, this unfortunate possibility is being averted by the
energy and thrift of the sheepmen in breeding sheep that produce more
and better wool than was the case in the past. The sheep which Columbus
brought to this country, and, in fact, all the sheep of the world in
that day, produced wool of very coarse, inferior quality, and but very
little of it. One hundred years ago our sheep did not average three
pounds of wool per head, but by careful breeding and better feeding we
have brought the average fleece up to slightly more than seven pounds.
Of course, some sheep produce decidedly more wool than this, but the
fact that in one hundred years we have more than doubled the amount of
wool that a sheep produces and increased its quality very materially
speaks well for the ingenuity and determination of our sheep producers.
Probably as time goes on the average fleece may be still further
increased, so that in the next twenty-five years it is not too much to
hope that our sheep will produce on an average of one pound more wool
than they now do.

Of course, as wool comes from the sheep, it naturally contains much
dirt. The sheep have run on the range or in the open pasture during
much of the year, and dust and dirt has settled into the wool. Then,
besides producing wool, the sheep excrete into the wool a fatty
substance known as wool fat. When the fleece is taken from the sheep
and sent to the market the first thing that the manufacturer does with
the fleece is to wash out all this foreign matter. The foreign matter
is of a considerable quantity, for 60 per cent of wool as it comes from
the sheep is dirt and grease, so that only 40 per cent of the sheep’s
fleece represents wool fibres.

This wool fibre is a very delicate affair, being made up of thousands
of little cells, one laid on top of the other. On the surface of the
fibre are a lot of scales arranged something like the scales on a fish.
In the process of manufacturing the scales on one fibre lock with
scales on another fibre, and in that way the fibres are held together
in the piece of cloth.

When wool is received at the factory it is in fleeces, and each fleece
contains different kinds of fibres--long and short--coarse and fine,
and it is necessary that these should be sorted into different kinds
or grades, as may be desired--perhaps six or eight different kinds,
according to the particular uses to which the different qualities are
to be put.

[Illustration:

  Copyright American Woolen Company

WOOL SORTING]

The fleece is spread out on a table, the center of which is covered
with wire netting, and through this netting part of the dust and other
matter from the wool falls while the sorting is going on. Sorters tear
with the hands the different parts of the fleece from each other and
separate them into piles, according to their different qualities.

All unwashed wool contains a fatty or greasy matter called yolk, which
is a secretion from the skin of the sheep. The effect of this yolk is
to prevent the fibres of the wool from matting, except at the ends,
where, of course, it collects dust, and, forming a sort of a coating,
really serves as a protection to the rest of the fleece while on the
sheep’s back.

After the wool is sorted it is next cleansed or scoured, in order to
remove all this yolk, dirt and foreign matter, and this is accomplished
by passing the wool, by means of automatic rakes, through a washing
machine, consisting of a set of three or four vats or bowls, which
contain a cleansing solution of warm, soapy water, until all the grease
and dirt have been removed.

Each bowl has its set of rollers, which squeezes out the water from
the wool before it passes into the next bowl. Having passed through
the last bowl and set of rollers the wool is carried on an apron made
of slats on chains, to the drying chamber, called the dryer, where is
taken out most of the moisture.

The wool is now blown through pipes or carried on trucks to the carding
room.

~DIFFERENCE IN WOOLENS AND WORSTEDS~

From this point the wool follows one of two different processes of
manufacture--that of making into worsteds or that of making into
woolens.

Speaking in a general way, worsted fabrics are made of yarns in which
the fibres all lie parallel, and woolens are made of yarns in which
the fibres cross or are mixed. Ordinarily, worsteds are made from long
staple wools, and woolens from short staple wools.

[Illustration:

  Copyright American Woolen Company

WOOL SCOURING]

By means of the comb the fibre is still further straightened out, the
short stock and noil, or nibs, are removed, and when the sliver comes
from the combs most of the fibres are parallel to each other. A number
of the slivers taken from the comb are then put through two further
operations of gilling, and wound into a large ball, which is called a
finished top.

The next process in the manufacture of worsteds is carding. In this
process the wool is passed between cylinders and rollers, from
which project the ends of many small wires. These cylinders revolve
in opposite directions. The result is the opening, separating and
straightening of the fibres; and the wool is delivered in soft strands,
which are taken off by the doffer comb and wound upon a wooden roll
into the shape of a large ball, known as a card-ball or card-sliver, or
put into a revolving can. The sliver from a number of these balls or
cans is now taken and put through what is known as the gilling machine,
which to a degree straightens the fibres.

From the gilling machine the wool comes off in soft strands. Four
strands are then taken to the balling machine, where is made a large
ball, ready for the combing. It takes eighteen of these balls to make a
set or fill up the comb.

The dyeing is done in three ways--in the top, in the thread or skein
after being spun, or in the piece after it is woven. If the wool is to
be stock dyed--that is, dyed in the top--it is sent to the dyehouse to
be dyed the shade required, and afterwards returned to be gilled and
recombed ready for the drawing.

[Illustration:

  Copyright American Woolen Company

WORSTED CARDING]

Up to this point there has been no twist given to the wool, nor any
appearance of a thread. The top, the soft untwisted end, is now run
through the drawing machine, the process sometimes consisting of nine
distinct operations, and is drawn and redrawn until reduced to the size
required for its special purpose; and the stock is then delivered to
the spinning room on spools, and is called roving.

[Illustration:

  Copyright American Woolen Company

GILLING AFTER CARDING]

[Illustration:

  Copyright American Woolen Company

COMBING]

In the spinning the process of drawing continues until the twisted
thread is reduced to the size required, which, either singly or twisted
together in two, three or four strands, is to be used for weaving.

The yarn is then very carefully inspected, and all imperfections which
would show in the finished goods are removed, and, if it is to be dyed
in the skein, the yarn is taken to a reel, where the skeins are made
ready for the dyehouse.

~HOW CLOTH IS MADE FROM WOOL~

The threads must now be prepared for the loom, in order that the actual
weaving may be done. The thread is used in two ways in weaving--as
warp, which is the thread which runs lengthwise of the cloth, and as
filling, or woof, which runs across the cloth from side to side.

[Illustration:

  Copyright American Woolen Company

GILLING AND MAKING TOP AFTER COMBING]

The warp threads--the threads which run lengthwise of the cloth--are
sized and wound upon large reels, and from these transferred to a large
wooden roll called the warp beam, which holds all the warp threads,
usually several thousands.

The filling threads are put on shuttle bobbins and placed in the
shuttles to be refilled by the operatives as required, and as the
weaving progresses.

The warp beam is then taken to the drawing-in room, where these several
thousand threads are drawn through wire heddles in a frame called the
harness, then drawn through a wire reed. The completed warp beam is now
ready for the loom.

The harnesses are placed in the loom, and by means of what is called
the “head-motion,” part of the threads are raised and part are lowered.
This allows the filling shuttles to pass above some threads and below
others, filling out the pattern required.

The cloth, having been made in such length as is desired, is taken from
the loom, and, by what is known as burling and mending, any knots or
threads woven in wrongly are removed, and any imperfections which have
been discovered through a careful examination are corrected.

The web or cloth is scoured or washed and the oil and any foreign
matter removed.

Undressed fabrics would now be fulled. This consists of running cloth
through a fulling machine, where, moistened with a specially prepared
soap, it is subjected to a great pressure and pounding, which aids in
giving the required finish.

There are different kinds of finishes which require different
treatments, and it would be impracticable for us to dwell in detail
upon this matter here.

If dyed in the piece, the web or cloth is taken to the dyehouse and
dyed. It is thoroughly rinsed, all moisture is extracted from it, and
it is dried.

After drying the cloth is run through a machine by which it is brushed
and sheared, the brushing lifting the long fibres, and the shearing
cutting them off at even length. The cloth is put through the press,
which irons it out, giving it the lustre or the finish that is desired.
It is examined again for further imperfections, and if such have
occurred they are corrected.

Measuring, weighing, rolling and tagging follow, and the cloth is
packed and ready for the market.

Woolens are made from short staple wools, known as clothing wools, and
in the finished woolens the fibres of the yarns cross or are mingled
together. In the case of woolens, after the scouring, it is frequently
necessary to remove burrs or other vegetable matter from the wool. To
accomplish this the wool is dipped in a bath of chloride of aluminum or
sulphuric acid solution, then the moisture is extracted and the wool
is put through a drier, where the temperature must be at least 212
degrees. This heat carbonizes the foreign substance, but has little
effect on the animal fibres of the wool.

[Illustration: FINISHING BOX

ENGLISH DRAWING

  Copyright American Woolen Company

GILLING

ENGLISH DRAWING

  Copyright American Woolen Company]

Next, an ingenious machine called the burr picker removes the burr.

Sometimes there is to be a blend of the wool with other stocks, and in
that case the several different wools are mixed together.

[Illustration: GILLING, FIRST OPERATION

ENGLISH DRAWING

  Copyright American Woolen Company

REDUCER

ENGLISH DRAWING

  Copyright American Woolen Company]

~HOW WOOLEN CLOTH IS DYED~

Dyeing of woolens is done in three ways--in the wool, in the thread
after it is spun, or in the piece after it is woven. If the wool is
to be “dyed in the wool” it is now conveyed to the dyehouse, dyed the
shade required, then returned to the mixing room.

During the process of scouring, when the yolk was removed, a large part
of the natural oil of the wool was also eliminated, and, in order to
restore this lubricant, the wool is sprinkled with an oil emulsion, and
the mixing picker thoroughly blends the wools.

From here the wool goes to the cardroom, and by means of the carding
machine the fibres are carded and drawn and delivered to the finisher
in a broad, flat sheet. By means of the condenser it is divided into
narrow bands, and the wool--free as yet from twist--comes out in soft
strands. These strands or threads are called roping.

[Illustration: MENDING ROOM

  Copyright American Woolen Company

BURLING RAISING KNOTS

  Copyright American Woolen Company

MENDING PERCHING

  Copyright American Woolen Company]

[Illustration: DRAWING IN WARP THREADS

  Copyright American Woolen Co.

  Copyright American Woolen Co.

  Copyright American Woolen Co.

WEAVING AND SCOURING]

Now comes the mule spinning. The roping passes through rolls by which
it is drawn and twisted to the size required, and wound on paper cop
tubes or bobbins. Such of the yarn as is to be used for warp is then
spooled from the bobbins to dresser spools. It is sized and wound upon
large reels: from these transferred to the warp beam, as in the case of
worsteds.

The processes of drawing-in, preparation for weaving, burling and
mending are practically the same as in the case of worsteds.

~HOW THE CLOTH IS MADE PERFECT~

The finishing processes of woolens, like the finishing processes of
worsteds, vary with different fabrics, some fabrics being scoured and
cleansed in the washers before fulling, others going to the fulling
mill without cleansing. After fulling, the cloth is again washed
and rinsed, and if necessary to remove any vegetable fibres it is
carbonized.

Napping or gigging raises the fibres to the nap desired. Gigging is
done by means of a wire napping machine or teasel gig, which raises
the ends of the fibres on the face of the cloth. The teasel is a
vegetable product about the shape of a pine cone, and it is interesting
to note that no mechanical contrivance has ever been invented to equal
it for the purpose.

[Illustration: SPINNING THE WOOL

  Copyright American Woolen Company

ENGLISH CAP SPINNING]

The napping which has been raised by the teasel is sheared or cut to a
proper length by machine. The cloth is pressed, and, if it is desired
to finish it with lustre, it is wound upon copper cylinders and steam
is forced through it at a high pressure.

[Illustration:

  Copyright American Woolen Company

RING TWISTING]

[Illustration:

  Copyright American Woolen Company

BEAMING--YARN INSPECTING]

[Illustration:

  Copyright American Woolen Company

WOOLEN MULE SPINNING]

[Illustration:

  Copyright American Woolen Company

FINISHER WOOLEN CARDING]

Next the cloth is dyed, if it is to be piece-dyed--that is, dyed in
the piece. If the cloth is a mixture, the wool was dyed immediately
after the scouring. In worsteds the dyeing is done either just after it
has been subjected to the first combing processes, or the yarn is dyed
in the skein or hank.

[Illustration:

  Copyright American Woolen Co.

PIECE DYEING

  Copyright American Woolen Co.

FULLING CLOTH

  Copyright American Woolen Company

FINISH PERCHING]

[Illustration:

  Copyright American Woolen Company

FINISHED CLOTH, READY FOR THE TAILOR]

In the dry finishing the cloth is finished with various kinds of
finishes desired, and it is steamed, brushed, sheared and pressed.
Another examination for any imperfections or defects follows; the cloth
is measured, packed and tagged and is ready for the market.

The difference between worsteds and woolens is principally that in the
threads or yarns from which worsteds are made the fibres of the wool
lie parallel, one to another, being made from combed wool, from which
the short fibres have been removed; and woolens are made from yarns in
which the fibres cross and are matted and intermixed. When finished
the effect of worsteds and woolens is materially different. Upon
examination it will be found that the worsted thread resembles a wire
in evenness, while the woolen thread is uneven and irregular.

A worsted fabric when finished has a clear, bright, well defined
pattern, seems close and firmly woven, and is of a pronounced dressy
effect; while woolen cloths are softer, they are more elastic, the
colors are more blended, the threads are not so easily distinguishable
and the general effect is duller.




Why Can’t We See in the Dark?


We cannot see in the dark because there is no light to see by. To
understand this we must first understand that when we see a thing, as
we generally say, we do not actually see the thing itself, but only the
light coming from it. But we have become so used to saying that we see
the thing itself that for all practical purposes we can accept that as
true, although it is not scientifically exact. Scientifically speaking,
we see that part of the sunlight or other light which is shining upon
it, which the object is able to reflect.

If there were no air about us we could not hear any sounds, no matter
how much disturbance people or things created, because it requires air
to cause the sound waves which produce sound, and air also to carry
the sound waves to our ears. In the same way, if there is no light
to produce light rays from any given object to our eyes, we can see
nothing. It requires light waves to produce the reflections of objects
to our eyes. Without light our eyes and their delicate organs are
useless. You cannot see yourself in a mirror when the quicksilver which
was once on the back of the glass has been removed, because there is
then nothing to reflect the light. We can only see things when there is
light enough about to reflect things to our eyes. When it is dark there
is no light, and that is the reason we cannot see anything in the dark.




Why Can Cats and Some Other Animals See in the Dark?


They cannot see in the real dark any more than human beings. These
animals can find their way in the dark and can see more than a human
being, because of one distinct difference in their eyes, which may for
them be considered an advantage. The pupils of their eyes can be made
much larger, and they can, therefore, let more light into their eyes
than people. The result is that when it is so dark that you cannot
see a thing and you decide it is really dark, the cat can still see,
because there is always a little more light left and she can open the
pupils of her eyes and make them larger, thus letting in more light,
and the little bit of light there is still left gets into her eyes and
she is able to see. But in a really dark room a cat could see no more
than you can. You see, our eyes open and shut more or less just like
those of the cat, according to the intensity of the light. When you go
out of the dark and shaded room into the bright sunlight and look at
the sun, you naturally squint your eyes without deliberately intending
to do so. This is nature’s way of preventing too much light getting
into your eyes at one time. Gradually the pupils of your eyes contract
and get smaller, until you can see, without squinting, anything in
the sunlight. If, then, you were to go right back into a dark or
shaded room, you would have to wait a moment or two before you could
see things distinctly in the room--until the pupils of your eyes had
dilated (become larger), so as to let in enough light to enable you to
see normally. The eye automatically enlarges and contracts the pupil of
the eye, to enable us to see distinctly in either light or less light
places.




Why Is It Difficult to Walk Straight with My Eyes Closed?


The reason we cannot do this always is because when we walk naturally
the steps taken by our right and left feet are not of equal length.
This difference in the length of the steps is due to the fact that our
legs are never exactly the same length. We think of them generally as
of the same length, but they are not, and this will be proven if you
measure them accurately. Now, then, the longer of the legs will always
take a longer step than the shorter one, and so, if our eyes are shut,
we walk in circles, unless we have something to guide us. When we
walk with our eyes open, we are able to overcome the tendency to walk
in circles, because our eyes help the brain to direct the legs on a
straight course. Another reason which affects the matter is that our
eyes are very necessary in keeping our bodies balanced on our feet, and
it is very difficult to learn to keep the body balanced with the eyes
closed. Now, when your eyes are closed and you attempt to walk in a
straight line your body balances from one side to the other, and this
fact, coupled with the first reason given, makes your course irregular.
But, say you, the man on the tight-rope has his eyes bandaged and he
walks a very straight line. Yes; but remember that he has a straight
tight-rope to guide him, and all he needs is to maintain his balance.
One can learn to walk in a straight line with the eyes closed, but it
takes a good deal of practice, as you will learn if you try.




Why Can’t We Sleep with Our Eyes Open?


We cannot sleep with our eyes open, because to be asleep involves
losing control of most of the functions of the body. When we sleep
the brain sleeps also. Perhaps it would be stated more clearly to say
that we cannot sleep while the part of the brain which controls our
activities is awake. There is a part of the brain which has the power
to open our eyes, i. e., lift the eyelids, and when that portion of the
brain ceases to exercise its power to keep the eyes open, they go shut.
Even when we are awake that part of our brain cannot keep our eyes
from winking, because there is another part of the brain which sees to
it that our eyes wink every so often. This is done for the purpose of
washing the eye-ball, and is the answer to another of your questions
which is given in another place in this book. When the engineer at the
electric light plant shuts off the power all the lights go out, and
when you go to sleep you automatically shut off the power that opens
your eyes, and the eyes are shut. The brain is asleep also, and if it
is not completely asleep, you are restless.




Why Do Our Eyes Sparkle When We Are Merry?


If you should watch very closely the eyes of a merry person when you
see them sparkle you would probably notice that the eyelids move up and
down more often under such conditions than ordinarily, and if you know
what moving the eyelids up and down in front of the pupil of the eye
does, you will have your answer.

Every time the eyelid comes down it releases a little tear, which
spreads over the eyeball and washes it clean and bright. It does this
every time the eyelid comes down. Now, there is something about being
merry which has the effect of making the eyelids dance up and down,
and thus, every time the lid comes down, the ball of the eye is washed
clean and bright, and gives it the appearance of sparkling, as we say.




Why Do We Laugh When Glad?


We laugh when glad because the things which make us laugh combine
together to rouse those parts of the body which are involved in a
good laugh to act in a certain harmony, and when this combination is
arranged in a certain way it produces a laugh. Certain things in the
world, whether they are funny, ludicrous, or other things that produce
the laughing effect, cause the brain to work certain muscles and
nerves in a combination that produces a laugh. The impression which
reaches the brain causes these muscles and nerves to act involuntarily
and the laugh comes. It works just like the keys of the piano. Some
combinations of notes produce sad sounds and other combinations produce
glad sounds, but the combination when once touched will always produce
the same sound. It is the impressions made on the brain which start the
proper combination, and it does this instantly. Just as a pin prick in
the arm will at once send a “hurt” message to the brain and cause the
brain to jerk the arm away, so a laugh-producing combination of sounds,
or things we see, or feel, sends an impression to the brain which at
once sends out the “laugh” order. Some things make some people laugh
while they do not affect others at all. That is because our brains are
not always the same in regard to recording impressions. Some things
impress some brains one way and others entirely in a different way or
not at all. You do not laugh so heartily the second time you hear a
funny story, because the impression the brain receives when the story
is told the second time is not so vivid.




Why Do I Laugh When Tickled?


Practically the same things happen when we are tickled, and explains
why you laugh when tickled. When some one tickles the bottom of your
feet or your ribs or another part of your body it produces, in most
cases, the same effect on the brain as the laugh-producing sound or
sight, and arouses the same combination of muscles and nerves to
activity. It is just like pushing the button of an electric bell. When
you push the button the contact produces the spark which sets the
machinery of the bell in motion and the bell rings and will continue
to ring as long as you keep your finger on the button, or until the
spark-producing power of the battery is gone. Then, as in the case
of the bell, you cease to laugh, because the spark that produced the
laugh combination is gone. That is why some things tickle some people
very much and do not affect others. Some are not so sensitive to the
laugh-producing combination as others. After the thing that tickles you
has been going on for some time you are not tickled into laughter any
more, because the impression on the brain ceases to be as strong.




Why Don’t I Laugh When I Tickle Myself?


Your mind tells you there is no need to laugh when you tickle yourself.
Your mind will not respond to the tickling sensation when it is aware
that the cause of the tickle is yourself. The reflex action of the mind
which causes laughter and squirming when some one else tickles you only
acts when it is not conscious of the cause.

The whole purpose of the sensitive organization of our skins is to
give us information and cause action which will enable us to protect
ourselves when any outside influence touches us. An injurious touch
causes shock and pain, and the harmless tickle arouses the laughing and
squirming sensation.




What Happens When We Laugh?


Laughter is what we call a reflex action. When something occurs to
make us laugh, whether it is something we see, or feel, or hear, it is
because certain sensory nerves receive an impression in one of three
ways, carry it to the nerve centre and the nerve centre then sends
the same impression along certain efferent nerves, which connect with
certain muscles or glands, and excite them to activity. The action is
practically the same as when you hold a light before a mirror. The
rays from the light strike the surface of the mirror and are reflected
back from the surface, lighting perhaps corners of the room, which the
direct rays from the light could not reach, all depending upon the
angle of reflection. Light will always reflect from a mirror that is
exposed to it.

Now, then, when you see, hear or feel anything that makes you laugh,
the sensory nerves have only to receive the impression to bring on
the explosion of laughter. Something touched the laugh nerves or the
laugh trigger that caused it to go off. You can prove that it is a
matter of impression entirely by noting that some people can listen
to a perfectly funny story, even when told by a clever performer, and
never crack a smile, while others burst into uncontrollable laughter,
and he who does not even smile may be listening even more intently than
the other--he may even be looking for a laugh. It all depends upon the
impression that is made upon the nerves. The muscles have the power
to express the state of gladness which is indicated by laughter when
certain impressions pass along the nerves which operate them, just as
they can be made to do other things when the proper cause for action is
shown them.




Why Do We Cry When Hurt?


We cry when we are hurt for the same reason that we laugh when we
are glad. The muscles and nerves, under the direction of the brain,
produce the cry just as the muscles and nerves produce laughter,
although they are probably, but not necessarily, a different set of
muscles and nerves.

When we are hurt in any part of our body or feelings the impression
does not affect us until it reaches the brain. Then instantly, of
course, the body and brain go to work to destroy the pain. The first
thing, of course, is to give a warning to other parts of the body that
there is a hurt, and our crying is a warning to other people that we
are hurt. That is probably the only good that crying does. It does not
remove the hurt--it only tells others of our troubles. We cry with the
lower part of the brain--the only portion of the brain which is active
in a little baby. This is why even a tiny baby can cry. Crying is the
only thing a baby can do to give warning of its distress or discomfort.
Later in life the upper part of the brain develops. This is the master
of the lower part. Therefore, we do not always cry when hurt as we grow
older, because the master brain sometimes tells the lower brain that to
cry will not help matters in the least, even though we are inclined to
cry. Sometimes the hurt or shock to older people is so great or sudden
that we cry out before the controlling part of the brain has had time
to get in its work of preventing the outcry, but we are able to stop
crying when the master brain again secures control.




Where Do Tears Come From?


Tears are not made only when we cry. They seem to come only when you
cry, because it is then that they spill over. A little part of you
is making tears all the time, and your eyes are constantly washing
themselves in them. You have often noticed how you wink every few
seconds? You have often tried to keep from winking--to see how long
you could keep from winking. Boys and girls often do that, and when
you keep from winking what seems a long time, you notice how your eyes
ache and feel very dry just before you have to let them wink, in spite
of how hard you try not to, and just when you think you are not going
to. I will tell you just what winking does for the eyes. All of the
time your eyes are open the front, or the part you see things with, is
exposed to the dust and dirt that fills the air at all times, although
we cannot always see the dust. The wind, too, is constantly making them
dry. But have you ever noticed that although you never wash the inside
of the front of the eye, or pupil, it is always clean? Well, it is
because your eye washes itself every time you wink. I will tell you how
this is done. Up above each eye, inside, of course, there is a little
gland called the tear-gland. This gland is busy all the time you are
awake making tears. As soon as the front of your eye becomes dry, or
if a particle of dust or anything else strikes it, the nerves you have
there tell the brain, and almost at once the eyelid comes down with a
tear inside of it, and so washes the front of your eye clean again. It
does its work perfectly and as often as necessary. There is always a
tear ready to be used in this way.




Where Do the Tears Go?


Let me show you. Look right down here at the inner corner of my eyelid,
where you will see a little hole. That is where the tears get out of
the eye, when they have washed your eyeball clean. Where do they go
then? Did you ever notice how soon after you cry you have to blow your
nose? The reason for that is that when the tears go through the little
hole they run down into the nose. This making of tears and winking
goes on all the time while you are awake, and after they wash your eye
off they go on out through this little hole. But when you cry you make
more tears come than you need, so many, in fact, that they cannot all
get away through this little hole, and as there is no place else for
them to go, and as there is no place to keep them inside the eye, they
simply spill themselves right over the edge of your lower eyelid and
run down your cheek.




Story in a Barrel of Cement


What Is Cement?

The dictionary tells us that cement is “any adhesive substance which
makes two bodies cohere.” Thus any material performing this function
may be called cement, such, for example, as the cement used in mending
broken china. Glue also is a form of cement. This story has to do with
Portland cement, which is a structural or building material used in
countless ways.


Why Is Cement Called Portland Cement?

After being wet with water it hardens into stone, and it was given the
name “Portland” because, when first manufactured in England, and mixed
with sand and stone, it resembled a celebrated building stone called
Portland, which was obtained from the Isle of Portland. Compared with
other American industries, the manufacture of Portland cement is of
recent origin. Formerly all Portland cement was brought from foreign
countries. After successful manufacture became established in this
country, however, the industry advanced with great rapidity. A few
years ago the entire United States did not use as much cement as is
now used in any one of our large cities. At the time these facts were
written (1914) the manufacturers were making more than 90 millions of
barrels a year.


What Is Cement Made Of?

Portland cement is composed chiefly of lime, alumina and silica. It
is manufactured from rocks, marl, clay and shale containing these
ingredients. If any one of them is lacking in the raw material as it
is taken from the earth, it is supplied during process of manufacture.
The greatest cement district in America is in Pennsylvania, and is
known as the “Lehigh District.” A rock containing proper constituents
for making Portland cement was found there in vast quantities, and for
a number of years the Lehigh District was the center of the industry.
In time it was found that certain clays, marls and shale could also be
manufactured into Portland cement, and thus mills have been erected
in all sections of the United States. One of the largest companies
in the United States found that cement could be manufactured from a
combination of blast-furnace slag and limestone, and this is now made
by the company in large quantities, the product being a true Portland
cement.


What Is Concrete?

Portland cement is the strongest and most lasting of all modern mortars
or binding materials. When mixed with sand and stone the resulting
mixture is called concrete. Being a plastic material when first mixed,
it cannot be used as we use brick or stone, but must be poured into
molds or forms, which hold it in place until it hardens into rock. It
may be cast in any form or shape, and thus it is useful for a vast
number of purposes. It will harden under water, and time and exposure
to the elements merely increase its strength. The most common form in
which it is used, one familiar to everybody, is in the construction
of sidewalks. It is used in all great engineering projects, such as
the building of dams, bridges, retaining walls, sewers, subways and
tunnels. Being fireproof, large quantities of it are used in buildings
and likewise on our farms, where it is extremely valuable as an
enduring and sanitary material.


What Is Cement Used For?

It has been said that concrete is a plastic material, meaning that
it is soft and pliable in the sense that clay or putty are plastic.
For this reason it is cast in forms or molds. Sometimes it is used in
the form of plain concrete, and on other occasions it is reinforced,
meaning that iron rods, steel bars or woven wire mesh are imbedded
in the concrete. When we speak of a “reinforced” concrete building,
imagine a huge wire bird cage encrusted within and without with
concrete. Place a block, beam or column of concrete upon the ground and
it will bear a tremendous load, meaning that it has great strength in
compression. On the other hand, if we were to place a long beam upon
supports at either end, leaving the greater length of it suspended and
without support, it would carry but a small load compared with concrete
in compression. Therefore, in making concrete beams or girders in a
building, strong steel bars are embedded in the concrete to take up
what are termed the tensile strains.

[Illustration: WHAT A CEMENT MILL LOOKS LIKE

This is a picture of a cement mill. Millions of dollars are invested in
these great mills, which are now located in practically all sections of
the country. Material is brought from the quarry to the mills, where it
passes through various stages, such as grinding, burning and bagging.
Expert chemists are employed to see that the cement is made exactly
right. It is a very scientific matter to make a thoroughly good cement.
There must be no guess work. Some mills are very large, the plant
comprising a number of buildings, and some companies operate several
mills in different localities. A single company supplied all of the
cement used in the Panama Canal, which great project required more than
six million barrels.]

[Illustration: This picture shows a quarry in the famous Lehigh cement
district. The giant steam shovel or excavator burrows into the hill
like some great animal, and when the bucket is full it is dumped into
the cars shown on the track, which convey the rock or the raw material
to the mill.]

[Illustration: WHERE THE MATERIAL IS OBTAINED

This is an illustration of a method of excavating and loading marl
and clay to be manufactured into Portland cement. The large bucket
suspended over the cars does not gouge into the hillside as shown in
the preceding picture, but descends like a huge steel hand, the metal
parts opening and closing like fingers. The long derrick elevates the
bucket and swings it over the train of cars.]

[Illustration: This is a view of a powerful rock crusher, which is
operated by the electric motor shown at the right. The cement rock is
brought from the quarry and dumped into the machine, from which it
issues in broken fragments, as shown in the illustration, this being
the first or preliminary crushing process.]

[Illustration: THE HUGE ROCK GRINDERS

This is a view of the electric motors operating the grinding machines
which reduce the raw material to a very fine powder. There are various
types of mills or grinders, to which the material comes after going
through the rock crusher. They grind it in preparation for the kilns.]

[Illustration: The kiln is a very important feature of the cement
plant. The finely ground raw material must be calcined or burned before
it becomes Portland cement. These kilns range from 60 to 240 feet in
length. They are slightly inclined and revolve upon rollers. The finely
ground material enters the kiln at the upper end and travels throughout
its length as the kiln slowly revolves. Powdered coal dust is fed into
the kiln at the lower end, where it is ignited and generates intense
heat. When the finely ground raw material comes into contact with the
heat, which reaches 2800 degrees F., it is transformed into what is
known as clinker, which issues from the lower end of the kiln and is
passed on to other machinery, which grinds it into impalpable powder or
Portland cement.]

[Illustration: HOW CONCRETE IS MIXED

This is an ingenious machine which bags and weighs the cement. The
bags are suspended as shown, and when filled and weighed by the
machine are placed in barrels and shipped to their destination. Every
device of this kind that will save time and labor cheapens the cost of
manufacture.]

[Illustration: In mixing cement, sand and stone together in order that
concrete may be obtained, it is customary to use, if the operation
is a large one, what are known as mechanical mixers. These are large
iron cylinders into which the three materials are put and water added.
The cylinder or iron drum revolves until the contents are thoroughly
mixed, when they issue from the mixer through a chute or spout. A mixer
of this type is shown on a succeeding page describing the making of a
concrete road. This picture shows mixing concrete by hand. The sand and
cement are first thoroughly mixed in the dry state and subsequently the
stone and water are added. Concrete should be thoroughly mixed in order
that every grain of sand may be entirely coated with cement, and then
these two combined make a rich mortar, which should surround entirely
every piece of stone.]

[Illustration: HOW CONCRETE BUILDINGS ARE MADE

This picture shows how concrete houses or walls are built through the
use of what are known as forms. In building a wall we have an inside
and outside form, as shown in the picture, between which the concrete
is placed. After it hardens the forms are removed. In some operations,
such as the construction of a large factory building or great bridge,
there is such a vast array of timber construction as to make the scene
quite impressive, especially when bridge arches of great span and
height are under construction.]

[Illustration: This is a view of an arch built of concrete during the
Jamestown Exposition. It is a striking illustration of how concrete
may be used for both ornamental and practical purposes. In no field
has concrete proved to be of more value and economy than in the
construction of bridges, whether large or small. Some of the largest
bridges in the world are built of concrete, and in many cases iron
bridges are incased in concrete to keep them from rusting.]

[Illustration: CONCRETE HOUSES CANNOT BURN

This is a curious example of concrete construction. It is a coal
pocket, from which locomotives are supplied with fuel. Railroad
companies have adopted it because of its great strength and durability.]

[Illustration: Just as mammoth structures are created with poured
concrete, so we may produce the most delicate and ornamental patterns.
These are usually cast in plaster molds and often in molds of wood or
iron. Where undercut work is required, such as in the sun-dial shown, a
wood or metal mold could not be removed without injury to the concrete,
and so sculptors have invented the pliable glue mold, which can be
easily removed and which will spring back to its original shape if
necessary to use it a second time.]

[Illustration: Concrete in dwelling construction means the elimination
of fire danger and also cost of painting and repairs. This picture
shows a solid concrete house, parts of which have been encrusted with
beautiful tiles. Concrete has been successfully used in all types of
dwellings, from the humble abode of the workingman to the palace of
the multimillionaire. An entire house may be made of concrete, even to
the roof and stairways, and where a dwelling is constructed of this
material throughout, it is proof against fire and decay.]

[Illustration: HOW THE FARMER USES CONCRETE

This is an interesting example of concrete construction. It is a
large water tower which will never warp, rust or decay. In this field
concrete has been of great service, whether reservoirs are constructed
in the form of towers or tanks. As already stated, water does not
affect the life or strength of concrete, except to improve it.]

[Illustration: This is a concrete silo. A silo made of concrete is
merely a huge stone jar in which green food for cattle is preserved.
The crop is gathered and placed in the silo, thus insuring abundance
of green and wholesome food throughout dry seasons and during the
winter. The contents of the silo is known as silage or ensilage, and is
merely corn fodder cut when green. Concrete silos are both storm- and
fire-proof.]

[Illustration: It is usual to consider concrete in connection with
great engineering enterprises, but nevertheless many millions of
barrels are used each year by the farmers of the United States. This
picture shows a clean, sanitary and durable concrete stable. In
buildings of this character concrete is rapidly supplanting wood, which
soon goes to decay, to say nothing of accumulation of filth.]

[Illustration: HOW CONCRETE ROADS ARE BUILT

MECHANICAL CEMENT MIXER]

[Illustration: A CONCRETE ROAD

Our two last pictures relate to an exceedingly important and rapidly
increasing use of cement. It is the construction of concrete roads.
The first picture shows a concrete road in course of construction.
The mechanical mixer referred to above is shown in this picture. It
is a self-propelling machine and mixes the concrete very rapidly. As
it comes from the mixer in a wet and mushy mass it is placed between
rigidly staked side forms, where it hardens into imperishable rock.
The road is brought to its shape by working to and fro a long plank
called a template, after which the surface of the road is troweled with
wooden floats, giving it a texture which prevents horses and cars from
slipping. The last picture shows a narrow concrete road in the state of
Maryland. Wherever these roads have been built they mean much to the
women and children of the community. They never grind up into mud or
dust, and are as pleasant to walk upon as the sidewalks of the city.
Children, especially, delight in them. In Wayne county, Mich., where
they have the most celebrated concrete roads in the world, the children
go to and from school on roller skates, and various games are played on
the concrete road.]




Why Don’t We Make Roads Perfectly Level?


Roads are made with a curving upper surface, i. e., higher in the
middle, in order that the rain will drain away from the road into the
gutters or ditches which you find at the sides. You see water has the
faculty of running only in one direction, and that is downward. If it
cannot go down on one side or the other, it will collect in puddles
and make the road impassable. For this reason we build our roads so
they are higher in the middle than at the sides--not much higher; only
about six inches or so--giving them just the gentle slope toward each
side that is necessary to allow the water to run off gradually, but
sufficiently sloping to keep the water from collecting in puddles in
the road. Thus after the dust has been settled by the first rain that
falls, most of the surplus rain that falls on the roads finally runs
into the ditches at the side of the road.




Why Are Some Roads Called Turnpikes?


Undoubtedly the name turnpike as applied to some roads arose from the
fact that pikes or gates were set across the roads by the keeper or
toll-collector. In addition to collecting tolls, it was a part of the
toll-keeper’s business to keep the road in repair. His wages and other
expenses for doing this were received from the tolls collected from the
people who used the road to ride on in carriages, wagons, etc. In the
early days the toll-collector was armed with a pike, a long-handled
weapon with a sharp iron head, which he used to prevent people who
travelled his road from going by without giving up their toll. Later on
a swinging gate was built across the road, which made it unnecessary to
use the pike, though the name was retained, for no one could pass while
the gate barred the way. When the passerby had paid his tolls, the
toll-collector opened the gate and let him pass. If he did not pay the
gate remained closed and the driver had to turn back or decide to pay.
Hence comes the name turnpike. In some parts of the country they call
these toll roads.




What Is Dust?


A large part of the dust we see in the roadway when the horses kick it
up, or when an automobile passes, is made up of the pulverized dirt of
the roadway. It becomes mixed with other things, such as the street
deposits of animals, particles of carbon, etc. Particles of this dust
get into our throats, and as there are many germs in it, they are very
liable to cause sickness, especially the colds from which we suffer.




What Becomes of the Dust?


The dust of the roadway is generally blown away by the wind, to come
down to earth again wherever the wind happens to carry it--on the
lawns, the doorsteps or back to the road, perhaps. In any event, the
rain which is certain to come sooner or later, washes this dust back
into the soil, or into the sewers. Part of it mixes with the soil. The
organic matter in dust helps to fertilize the soil, and is therefore
useful. Other parts of the dust are oxidized and consumed by the
air, through the heat of the sun. So you see the dust is continually
changing from one thing to another.




Are Stones Alive?


Real stones are not alive. They do not become stones until they have
been burned out--until they have become what is known as dead matter.
This is meant entirely in the sense that we commonly think of the
meaning of the word “alive,” which is to be able to breathe and grow.
Stones can neither breathe nor grow. They belong to the inanimate
kingdom of things on the earth. Particles of this dead matter, found in
stones, etc., are in many cases taken up by things that are actually
alive, and help to form the bodies of living things.

The most common thing to be found in rocks and stones is what is
called “silicon,” and we find this silicon in the straws of the wheat,
oats and corn, and in many other things, but not in a way that can be
detected except by chemical analysis. A great many of the things found
in stones are found in living things, but rocks and stones are not
alive in any sense.




What and Why Is Smoke?


Smoke is produced only when something which is being burned is burning
imperfectly. If we were to put anything burnable into the fire and
establish just the right amount of draft, and knew how to build our
fires properly, there would be no smoke and very little ashes.

In the case of the black coal smoke which we think of mostly when
we think of smoke at all, the black portion is principally little
unburned particles of coal which pass up the chimney with the gases
which are thrown off when the coal is being burned. These gases would
be invisible--they really are invisible--if it were not for the little
particles of coal which are drawn up the chimney with them. If you look
at the chimney from which a wood fire expels the gases you find the
smoke very light in color--showing that not so much unburned matter is
being thrown off. A charcoal fire makes no smoke, because the charcoal
has had the unburnable things taken out of it beforehand, and the
charcoal stove is almost perfect in construction from the standpoint of
combustion.

Of course, the thickness of the smoke from a coal fire is often
increased by the fact that there are unburnable things mixed in with
the coal, some of which also pass off through the chimney.




Why Can’t We Burn Stones?


We cannot burn anything that has already been burned, and a stone has
already been burned. To understand how this is we must first find out
what takes place when a thing is burned. When a thing is burning it
means merely that that particular thing is taking into its system all
of the oxygen of the air that it can combine with. When it has done
this it cannot be burned any more. Of course, in doing this the thing
originally burned changes its character. The elements in a candle when
lighted mix with the oxygen in the air and disappear in the form of
gases. The elements in coal mix when fired with oxygen and change into
ashes, gases and smoke. A stone, however, is the result of a burning
that has already taken place. The original element of most of the rocks
and stones we see was silicon, and when that combines with oxygen,
the result is some form of rock, which you may be able to break up or
throw, but which you cannot burn again.




What Is Fog?


The fog which we generally think of when we speak this word is the
fog at or on the sea or other body of water--the one that makes the
ships stand by and blow their fog horns. A fog of this kind is nothing
more nor less than a cloud, come right down to earth and spread out a
little more. People who have gone up into the air in balloons and other
airships through the clouds, say that the clouds are only fogs, and
that above them it is as clear as it is on a sunshiny day on the water
when there is no fog.

There is another kind of fog which settles down over the land,
especially in the cities. It is a damp mist which combines with the
smoke and other impurities in the air and forms a black and dirty cloud
about everything. This occurs when the upper air prevents the smoke
which rises from a city with all its people and fires in the furnaces
from passing up and away. The upper air acts like a blanket and keeps
the misty, smoky air down, until the wind comes along and blows it away.




What Becomes of the Smoke?


There are a number of things in smoke, and when we know what they are,
we will find a natural answer to this question. First, there are, of
course, the little unburned particles of fuel which get carried up
the chimney by its drawing power. These naturally fall to the ground
of their own weight, once they get beyond the drawing power of the
chimney and out of the current of air so formed. Some of the gases
are already quite burned out when they pass up the chimney. There is
a lot of carbonic acid gas which, of course, mixes with the air and
eventually becomes food for the plants. Then there are some gases which
are not entirely burned, and the air burns them still more until they,
too, become carbonic acid gas, or water which is also thrown off by a
burning fire.




Why Does an Apple Turn Brown When Cut?


The reason is that when you cut an apple, the exposure to the air of
the inside of the apple causes a chemical change to take place, due to
the effect the oxygen in the air has on what is scientifically known as
the enzymes in the apple, or what are commonly called the “ferments.”
When the peel is unbroken it protects the inside of the apple against
this action by the oxygen. The brown color happens to be due to the
chemical action. The action is similar to the action of the air on wet
or damp iron or steel, in which case we call it rust.




Why Does a Piece of Wood Float in Water?


A piece of wood will float in water because it is lighter than the
same amount of water. We do not mean that a piece of wood weighing one
pound, for instance, would weigh any more than a pound of water, of
course, but if you took the measurements of each you will find that
it took less bulk to make a pound of water than of wood. If you had a
piece of wood so shaped that it just filled a glass completely, and
then took another glass and filled it with water, you would find that
the glass containing the water weighed the most. Another name to give
to this difference would be to say that the water was more dense than
the wood. By the law of gravitation the denser thing will always go
to the bottom, and as wood is less dense than water, it will stay at
the top if put in water. The piece of wood has more air in it than the
water. If you could expel the air from the piece of wood and then put
it in water, it would sink.




Why Does Iron Sink In Water?


The explanation in regard to the piece of wood floating in water is the
beginning of the answer to this question. A piece of iron is heavier
than an equal bulk of water, and will therefore go to the bottom, as
will all things which are more dense than water. A piece of iron has no
air in it. The particles of a piece of iron are so close together that
there is no room for air in it and it will therefore sink in water. A
piece of wood from which all of the air had been expelled would also
sink.




Why Doesn’t an Iron Ship Sink?


This is a very natural question for you to ask right after you were
told why iron sinks in water. The explanation is that by making an
iron ship in the way we do, we fix it so that it holds a lot of air in
between the bottom and sides, making the combination of the two--the
iron ship and the air in it--lighter than the water on which it sails.
Men thought at one time that a ship would sink if made of iron, and
therefore built all of their ships of wood. Finally one inventor made a
ship of iron and it was one of the wonders of the world. When we found
that iron ships would float if they were built to retain sufficient air
to keep them from sinking, we made the hulls of most ships of iron for
a time. Now, however, the best ships are made of steel, which is even
better.

If you bore a hole in the bottom of a ship, the water will run in if
the ship is in the water, and the ship will sink, because the water
coming in drives out the air; and when the ship is full of water,
the water in it, with the ship itself, are heavier than the water on
which it sails, and the ship will go down. Filling a ship with water
makes the iron part of the ship just like a bar of iron, so far as its
sinking qualities are concerned.

Of course, an iron ship must be made long enough and broad enough so
that when it is completed there will be sufficient air contained within
the hull to make the combination lighter than water. Always, therefore,
when a ship is to be built, competent engineers must go over the plans
of the vessel and calculate the air capacity, so as to make sure she
will float.

Nowadays it would be difficult to sink a modern vessel by boring one
small hole in the bottom, because the bottom and sides are lined with
enclosed steel air-chambers, and a ship will keep afloat even if one
or a number of holes are made. The reason is, of course, that when you
bore a hole into one of these air-chambers the water rushing in will
fill that air-chamber with water, but as there is no connection from
the inside with the rest of the ship, the water can get no further.




Why Does a Poker Get Hot at Both Ends if Left in the Fire?


Both ends of the poker become heated because the poker is made of iron,
and iron is a particularly good conductor of heat. To understand this
we must look into the question of what a good conductor of heat is.
In this case the particles of iron, which combined form the poker,
are so close together that when those at the end of the poker which
is in the fire get hot, the particles at that end hand the heat on to
the particles next to them, and so on until the whole poker is hot.
The difference between a thing which is a good conductor of heat and
a thing which is not a good conductor, lies in the ability of the
different particles which compose it to hand the heat on to the others.
Did you ever notice that the handle of a solid silver spoon will
become hot if the spoon is left in hot coffee? Solid silver is a good
conductor of heat. A plated spoon is not a good conductor, however, and
will not become hot if left in the cup of hot coffee as a solid silver
spoon will.




Would a Wooden Spoon Get Hot?


A wooden spoon would not get hot, because wood is not a good conductor
of heat. The atoms which compose the wood have not the power to
transmit the heat to each other. This is strange, too, when we think
that a poker is a good conductor of heat, but will not burn, while
wood is not a good conductor, but will burn readily. Perhaps you have
already discovered this in connection with a wood fire. One end of a
stick of wood may be burning fiercely, and yet you can pick it up by
the other end and find it is not even warm. This proves to you that
wood is not a good conductor of heat, and explains why the handle of a
wooden spoon in a bowl of hot soup will not get hot while the handle of
a silver spoon will.




Why Does Iron Turn Red When Red Hot?


The answer is that the piece of iron has been heated to the point where
it gives off light of its own. The red you see is only one stage in
the development of iron to the point where it makes its own light. If
you heat it still more it will make a white light. You know that it
produces the light itself, because if you take a piece of iron into a
perfectly dark room and heat it to a white heat it will show better
than where there is other light. If you continue the process the iron
will melt and change in form. Therefore, the “red hot” name for a piece
of iron in that state is a perfect name. It is a warning that the iron
is coming to a point where if the heating process is continued, it will
change its form and in this state, when treated according to known
methods, the iron is turned into steel, which has many characteristics
that iron does not possess. Now, I can, of course, hear you ask why
doesn’t an iron kettle get red hot? and I can answer that easily. If
you treat the kettle the same way as you do the piece of iron, it
will get red hot. The difference is that you are thinking of an iron
kettle with water in it. As long as there is any water in the kettle,
that keeps it from getting hot. The water inside keeps the kettle from
becoming red hot. If you took a hollow rod of iron and filled it with
water, it would not become red hot as long as any water remained in the
hollow portion.




How Did the Sand Get on the Seashore?


The sand on the seashore is nothing more or less than ground-up
sandstone. In dealing with the inanimate things in the world we find
that a very important element of all of them has been given the name
silicon. When the crust of the earth, which is the part we call the
land and rocks, and includes the part under the sea, was a molten mass,
this silicon was burned, combining with the oxygen which surrounded
everything, and produced what is known as silica. Silica is the name
given to the thing which is left after you burn silicon. A very large
part of this silica was deposited in parts of the earth, and when the
crust of the earth cooled off it was sand. By pressure and contact with
other substances it became stuck together, just as you can take wet
sand at the seashore to-day and make bricks and houses and tunnels,
excepting that in the case we speak of it was something besides water
that pressed and stuck the little particles of sand together. They
stuck together more permanently. Then when the oceans were formed, as
shown in another part of this book, much of the sandstone was found to
be at the bottom and on the shores of the oceans. The action of the
water continually washing against the sandstone gradually broke the
sandstone up into the tiny particles of sand again, and this is what
makes the sand on the seashore.




What Makes a Soap Bubble?


A bubble is merely a hollow ball of water with air inside. The air
in coming up through the water in trying to rise out of the water is
caught in the water in such a way as to form the bubble, and since the
ability of the air inside of the bubble to rise is greater than that of
the water which forms the bubble, and which has a tendency to pull it
down, the bubble rises into the air. The water ball is very thin and
keeps running down to the bottom of the ball, where you see it form
into drops, and soon this makes the walls of the water bubble so thin
that the air bursts through the ball of water, and that is




What Makes the Bubble Explode?


Sometimes we blow soap bubbles. We mix soap in the water and that makes
the walls of the water ball which we produce a little tougher, and it
requires a great deal more effort for the air to escape from it, as the
soap keeps the water in the walls of the bubble from running down to
the bottom for quite some time, and, therefore, soap bubbles will often
travel in the air for some distance. The colors we see on soap bubbles
are produced by the rays of sunlight, which strike the bubble and
reflect them back to us in colors very similar to those of the rainbow.




Why Are Bubbles Round?


Bubbles are round because the air which forms the inside of the bubble
exerts an equal pressure in all directions. It presses equally against
all sides of the bubble at the same time.




The Story in a Yard of Silk


God’s Creation and Man’s Invention.

~WHERE DOES SILK COME FROM?~

Silk in its finished state is an ideal product. It is at once durable,
magnificent to the eye, tender to the touch, and its rustle is soft
music to the ear. Hence it is easy to understand why the silkworm,
from the earliest times, has been an object of much consideration and
concern from a commercial and industrial point of view. In this country
alone, we annually expend as much for silk goods as we do for public
education and thirty times as much as we do for foreign missions. Such
an indomitable producer of wealth is the silkworm, and a producer of
wealth it has been from an age as remote as when Joseph was down in old
Egypt, interpreting the dreams of King Pharaoh’s butler and baker and
later that of the King himself.

To-day we speak of twenty centuries, and our minds can hardly
comprehend such a lapse of time. What shall we think of the silkworm,
that for twice twenty centuries has furnished practically all the
raw material for the world’s silk supply? Because man’s ingenuity is
at present actively engaged in the attempt to displace it by cheaper
substitutes, the thought has come to us that, without going too
minutely into mechanical processes, a good opportunity is presented
to give some interesting information in regard to the silkworm as
the creation of the Divine Hand, in contrast to the silkworm as the
creation of man.

According to Chinese authority, the use of silk dates from 2650 B.C.,
and it is generally conceded that, in point of age, it stands midway
among the great textiles, wool and cotton having preceded it, while
flax, hemp and other fibrous plants followed shortly in its train.

The first patron of the silkworm was Hoang-Ti, Third Emperor of China,
and his Empress, Si-Ling-Chi, was the first practical silkworm breeder
and silk reeler. It is related of her that she was once walking in the
palace gardens when she discovered a strange and repulsive looking
worm. It was small, of a pale green color, and was feeding greedily on
a mulberry leaf. She interested the Emperor in this strange creature,
and, at the Emperor’s suggestion, took the fine silken web which the
worm finally spun, and was the first to successfully reel the new
filament and weave it into cloth. So beneficial to the nation was her
work considered that her gratified subjects bestowed upon her the
divine title of “Goddess of the Silkworms,” and to this day the Chinese
celebrate in her honor the “Con-Con Feast,” which takes place during
the season in which the silkworm eggs are hatched.

In accounting for the presence of silkworms in the garden of this
early empress, we can rightly conclude that certain parts of China
have always abounded in forests of mulberry trees, and that the worms
themselves had existed in great numbers in a wild state and attached
their cocoons to the trees for ages before any use was discovered
for their web. In fact, such wild silkworms not only abound in China
to-day, but have also been found in Southern and Eastern Asia,
inhabiting the jungles of India, Pegu, Siam and Cochin China, but the
cocoons of these worms are, naturally, of a very inferior quality, and
are only used for the crudest kind of work.

[Illustration:

  Illustration by courtesy The Brainerd & Armstrong Silk Co.

THE INTRODUCTION OF SILK INTO EUROPE

Pilgrims brought silkworm eggs in their staffs, together with the
branches of mulberry trees, from China to the Court of Justinian at
Byzantine, A.D. 555. The penalty for taking silkworm eggs out of China
was death.

The accompanying illustration is a reproduction of a mural painting
on rep in the Royal Textile Museum at Crefeld, Germany, one of the
great silk textile centers of the world. The artist shows the pilgrims
presenting the silkworm eggs and the mulberry branches to Justinian,
beside whom, just in the act of rising, is his famous queen Theodora.]

Silk culture from the time of Hoang-Ti became one of the cherished
secrets of China. The headquarters of the industry was in the Province
of Chen Tong, where was produced the silk for the royal family. In
time the silk and stuffs of China became articles of export to various
portions of Asia. Long journeys were made by caravans, occupying
two-thirds of a year in going from the cities of China to those of
Syria, but the price obtained there exceeded the expense of the
journey, and thus left a large margin of profit to the merchants. In
this manner, for one thousand years, the Chinese sent their silk to the
Persians who, without knowing how or from what it was made, carried it
to the Western nations.

So carefully did the Orientals guard their secret, that there is reason
to believe that Aristotle was the first person in the occidental world
to learn the true origin of the wrought silk from Persia. In commenting
on the silk which was brought from that country on the return of
Alexander’s victorious army, he described the silkworm as a “horned
insect,” passing through several transformations, which produced
“bomby-kia,” as he called the silk. But the classics must convince one
that Aristotle’s discovery did not at once become matter of current
knowledge. In fact, for five hundred years after Aristotle’s time the
common theory of the origin of silk among the Greeks and Romans was
that it was either “a fleece which grew upon a tree” (thus confounding
it with cotton), or a fibre obtained from the inner bark of a tree; and
some, deceived by the glossy and silky fibres of the seed vessels of
the plant that corresponds to our milk or silk weed, believed it to be
the product of some plant or flower. So Virgil, in speaking of silk,
says, “the Seres comb the delicate fleecings from the leaves.”

In the Sixth Century, A.D., all the raw silk was still being imported
from China by way of Persia, when the Emperor Justinian, having engaged
in war with Persia, found his supply of raw silk cut off and the
manufacturers in great distress. His foolish legislation did not help
the situation, and a crisis was averted only by two Nestorian monks,
who came from China with seed of the mulberry tree and a knowledge
of the Chinese method of rearing worms. No one, on pain of death,
was allowed to export the silkworm eggs from China, but Justinian
bribed the monks to return to that country, and in 555 they came
back, bringing with them a quantity of silkworm eggs concealed in
their pilgrim’s staffs. And here let us say that there has only once
since been an important importation of eggs from Asia. That was about
1860, when Dr. Pasteur was making a study of a germ disease which was
threatening the industry. Consequently, it can truly be said that
practically all the silkworms of the Western world are descended from
those brought in the eggs by the monks to Constantinople. Justinian
gave the control of the silk industry to his own treasurer. Weavers,
brought from Tyre and Berytus, were employed to manufacture the silk,
and the whole production was a monopoly of the emperor, he fixing its
prices. Under his management, the cost of silk became eight times as
great as before, and the Royal Purple was twenty-four times its former
price. But this monopoly was not of long duration and, at the death of
Justinian in 565, the monopoly ceased, and the spread of the industry
commenced in new and diverse directions.

While every detail of the growth of the industry has an unusual
interest, as showing how such an insignificant thing as a worm may
become a potent factor in Nature’s economy, the scope of this article
will hardly allow us to more than sketch some of the other more salient
points of the history of the silkworm.

About the year 910, the silkworms made their appearance in Cordova,
Spain, being brought there by the Moors. From Spain silk culture soon
extended to Greece and Italy.

~WHEN SILK CULTURE WAS INTRODUCED IN AMERICA~

Silk was introduced on this continent through the Spanish Conquest of
Mexico, and the first silkworm eggs sold for $60.00 an ounce.

A century later royal orders were issued requiring mulberry trees to
be planted in the Colony of Virginia, and a fine of twenty pounds of
tobacco was imposed for neglect, and fifty pounds of tobacco was given
as a bounty for every pound of reeled silk produced.

Silk culture spread rapidly in the other Colonies, and to-day the story
of the ineffectual attempts to profitably rear the silkworm in this
country is as voluminous as it is interesting. Suffice it to say, as
a sop to our inherent Yankee pride, that silk culture was introduced
into Connecticut as early as 1737, the first coat and stockings made
from New England silk being worn by Governor Law in 1747, and the first
silk dress by his daughter, in 1750. This State, for the eighty-four
years following, led all the others in the amount of raw silk produced.
In Connecticut also, was built the first silk mill to be erected on
this continent for the special purpose of manufacturing silk goods.
This building was constructed in 1810 by Rodney and Horatio Hanks, at
Mansfield, and is still standing as an heirloom which has come to us
from the infant days of the industry.

The silkworm has become domesticated, since, during the long centuries
in which it has been cultivated, it has acquired many useful
peculiarities. Man has striven to increase its silk producing power,
and in this he has succeeded, for, by comparing the cocoon of the
silkworm of to-day with its wild relations, the cocoon is found to be
much larger, even in proportion to the size of the worm that makes
it or the moth that issues from it. The moth’s loss of the power of
flight and the white color of the species are probably the results of
domestication.

[Illustration: JAPAN THE NATURAL HOME OF THE SILK WORM

GATHERING MULBERRY BRANCHES.[1]

This picture shows a grove of mulberry trees from which branches
are being gathered as food for the worms. This is often done by the
children.]

[Illustration: FEMALE MOTHS DEPOSITING EGGS.[1]

The moths are placed upon pieces of cardboard, upon which they deposit
their eggs.

The cards with the eggs are kept in a cool place until the season for
hatching arrives.]

[Illustration: PREPARING COCOONING BEDS.[1]

This picture shows two boys preparing a bed of twigs or branches upon
which the worms may spin their cocoons.]

  [1] Illustrations by courtesy The Brainerd & Armstrong Co.

[Illustration: HOW THE SILKWORMS ARE CARED FOR

HATCHING THE EGGS.

As the eggs hatch on the cards, the young worms are removed to other
cards or trays, where they are fed and cared for.]

[Illustration: REMOVING SILKWORMS FROM CARDS WHERE THEY WERE HATCHED.

Every few days the young worms are changed to new and clean cards.]

[Illustration: METHOD OF REELING RAW SILK.

The cocoons are soaked in hot water in the basins shown in the front
to loosen the gum. The silk threads then pass through the hands of the
operators and are reeled on swifts in the cabinet shown in the rear.

A more modern appliance for reeling the silk is shown on one of the
following pages.]

  The foregoing pages and pictures by courtesy of Brainerd & Armstrong
  Silk Company, from their book entitled, “Silk, the Real versus the
  Imitation.”

[Illustration: FULL GROWN LARVA--SHOWING POSITION IN MOLTING.[2]]

[Illustration: MALE MOTH.[2]]

[Illustration: FEMALE MOTH.[2]]

[Illustration: SIDE VIEW OF CHRYSALIS.[2]]

[Illustration: BOTTOM VIEW OF CHRYSALIS.[2]]

  [2] The cuts on this page and balance of cuts in the story of silk
  copyright by the Corticelli Silk Mills.

The silk moth exists in four states--egg, larva, chrysalis, and adult.
The egg of the moth is nearly round, slightly flattened, and closely
resembles a turnip seed. When first laid it is yellow, soon turning
a gray or slate color if impregnated. It has a small spot on one end
called the micropyle, and when the worm hatches, which in our climate
is about the first of June, it gnaws a hole through this spot. Black
in color, scarcely an eighth of an inch in length, covered with long
hair, with a shiny nose, and sixteen small legs, the baby worm is born,
leaving the shell of the egg white and transparent.

~THE SILKWORM—HOW HE DOES HIS WORK~

Small and tender leaves of the white mulberry or osage orange are fed
the young worm which simply pierces them and sucks the sap. Soon the
worm becomes large enough to eat the tender portions between the veins
of the leaf. In eating they hold the leaves by the six forward feet,
and then cut off semi-circular slices from the leaf’s edge by the
sharp upper portion of the mouth. The jaws move sidewise, and several
thousand worms eating make a noise like falling rain.

The worms are kept on trays made of matting, that are placed on racks
for convenience in handling. The leaves are placed beside the worms,
or upon a slatted or perforated tray placed above them, and those that
crawl off are retained, while the weak ones are removed with the old
leaves. The worms breathe through spiracles, small holes which look
like black spots, one row of nine down each side of the body. They have
no eyes, but are quite sensitive to a jar, and if you hit the rack
they stop eating and throw their heads to one side. They are velvety,
smooth, and cold to the touch, and the flesh is firm, almost hard. The
pulsation of the blood may be traced on the back of the worm, running
towards the head.

The worm has four molting seasons, at each of which it sheds its old
skin for a new one, since in the very rapid growth of the worm the old
skin cannot keep pace with the growth of the body. The periods between
these different molts are called “ages,” there being five, the first
extending from the time of hatching to the end of the first molt, and
the last from the end of the fourth molt to the transformation of the
insect into a chrysalis. The time between the four “molts” will be
found to vary, depending upon the species of worm.

[Illustration: HOW THE SILKWORMS ARE REARED.[2]]

When the worm molts it ceases eating, grows slightly lighter in color,
fastens itself firmly by the ten prolegs, and especially by the last
two, to some object, and holding up its head and the fore part of its
body remains in a torpid state for nearly two days.

By each successive molt the worm grows lighter, finally becoming a
slate or cream white color, and the hair, which was long at first,
gradually disappears. The gummy liquid which combines the two strands
hardens immediately on exposure to the air.

The worm works incessantly, forcing the silk out by the contraction
of its body. The thin, gauze-like network which soon surrounds it
gradually thickens, until, twenty-four hours after beginning to spin,
the worm is nearly hidden from view. However, the cocoon is not
completed for about three days.

~SIXTY-FIVE MOTIONS OF HIS HEAD A MINUTE~

The cocoon is tough, strong, and compact, composed of a firm,
continuous thread, which is, however, not wound in concentric circles,
but irregularly in short figure eight loops, first in one place and
then in another. In doing this the worm makes sixty-five elliptical
motions of his head a minute or a total of 300,000 in an average
cocoon. The motion of the worm’s head when starting the cocoon is very
rapid, and nine to twelve inches of silk flow from the spinneret in
a minute, but later the average would be about half this amount per
minute.

[Illustration: SILKWORM EATING.[2]]

[Illustration: SILKWORM—ONE OF THE WORLD’S GREATEST WORKERS

SILKWORM PREPARING TO FORM ITS COCOON.]

Having attained full growth, the worm is ready to spin its cocoon. It
loses its appetite, shrinks nearly an inch in length, grows nearly
transparent, often acquiring a pinkish hue, becomes restless, seeks
a quiet place or corner, and moves its head from side to side in an
effort to find objects on which to attach its guy lines within which
to build its cocoon. The silk is elaborated in a semi-fluid condition
in two long, convoluted vessels or glands between the prolegs and
head, one upon each side of the alimentary canal. As these vessels
approach the head they grow more slender, and finally unite within the
spinneret, a small double orifice below the mouth, from which the silk
issues in a glutinous state and apparently in a single thread.

[Illustration: COCOON BEGUN--SILKWORM CAN STILL BE SEEN.]

The color of the worm’s prolegs before spinning indicates the color the
cocoon will be. This varies in different species, and may be a silvery
white, cream, yellow, lemon, or green.

[Illustration: COMPLETED COCOON.]

~WHEN THE SILKWORM’S WORK IS DONE~

When the worm has finished spinning, it is one and a quarter inches
long. Two days later, by a final molt, its dried-up skin breaks at the
nose and is crowded back off the body, revealing the chrysalis, an oval
cone one inch in length. It is a light yellow in color, and immediately
after molting is soft to the touch. The ten prolegs of the worm have
disappeared, the four wings of the future moth are folded over the
breast, together with the six legs and two feelers, or antennæ. It soon
turns brown, and the skin hardens into a tough shell. Nature provides
the cocoon to protect the worm from the elements while it is being
transformed into a chrysalis, and thence into the moth.

[Illustration: MOTHS EMERGING FROM COCOONS.]

With no jaws, and confined within the narrow space of the cocoon, the
moth has some difficulty in escaping. After two or three weeks the
shell of the chrysalis bursts, and the moth ejects against the end of
the cocoon a strongly alkaline liquid which moistens and dissolves
the hard, gummy lining. Pushing aside some of the silken threads and
breaking others, with crimped and damp wings the moth emerges; and the
exit once effected, the wings soon expand and dry.

[Illustration: COCOONS FROM WHICH THE MOTHS HAVE EMERGED.]

The escape of the moth, however, breaks so many threads that the
cocoons are ruined for reeling, and consequently, when ten days old,
all those not intended for seed are placed in a steam heater to stifle
the chrysalis, and the silk may then be reeled at any future time.

The moths are cream white in color. They have no mouths, but do have
eyes, which is just the reverse of the case of the worm. From the time
it begins to spin until the moth dies, the insect takes no nourishment.
The six forward legs of the worm become the legs of the moth. Soon
after mating the eggs are laid.

The male has broader feelers than the female, is smaller in size, and
quite active. The female lays half her eggs, rests a few hours, and
then lays the remainder. Her two or three days’ life is spent within a
space occupying less than six inches in diameter.

One moth lays from three to four hundred eggs, depositing them over an
even surface. In some species a gummy liquid sticks the eggs to the
object upon which they are laid. In the large cocoon varieties there
are full thirty thousand eggs in a single ounce avoirdupois. It takes
from twenty-five hundred to three thousand cocoons to make a pound of
reeled silk. Do you wonder that, centuries ago, silk was valued at its
weight in gold?

Growers of silk in the United States, by working early and late every
day during the season, which lasts from six to eight weeks, could
scarcely average fifteen cents for a day’s labor of ten hours. Silk,
once regarded as a luxury, is now considered a necessity.

[Illustration: HOW THE COCOON IS UNWOUND

REELING THE SILK FROM COCOONS BY FOOT POWER, CALLED “RE-REEL” SILK.

The cocoons are first assorted, those of the same color being placed
by themselves, and those of fine and coarse texture likewise. The
outside loose silk is then removed, as this cannot be reeled, after
which the cocoons are plunged into warm water to soften the “gum” which
sticks the threads together. The operator brushes the cocoons with a
small broom, to the straws of which their fibers become attached, and
then carefully unwinds the loose silk until each cocoon shows but one
thread. These three operations are called “soaking,” “brushing,” and
“cleansing.”

Into one or two compartments in a basin of warm water below the reel
are placed four or more cocoons, according to the size of the thread
desired. The threads from the cocoons in each compartment are gathered
together and, after passing through two separate perforated agates a
few inches above the surface of the water, are brought together and
twisted around each other several times, then separated and passed
upward over the traverse guide-eyes to the reel. The traverse moves
to and fro horizontally, distributing the thread in a broad band over
the surface of the reel. The rapid crossing of the thread from side to
side of the skein in reeling facilitates handling and unwinding without
tangling, the natural gum of the silk sticking the threads to each
other on the arms of the reel, thus securing the traverse. Silk reeled
by hand or foot power is known as “Re-reel” silk, while silk reeled by
power machinery is called “Filature.”]

[Illustration: A FILATURE--REELING THE SILK FROM COCOONS BY POWER
MACHINERY.[2]]

[Illustration: DRYING SKEINS OF SILK.]

[Illustration: THE SILK IS WOUND ON SPOOLS

WINDING FRAMES--WINDING THE SILK ON BOBBINS.]

~WHERE MAN’S WORK ON THE SILK BEGINS~

The raw silk is first assorted, according to the size of the fiber, as
fine, medium, and coarse. The skeins are put into canvas bags and then
soaked over night in warm soapsuds. This is necessary to soften the
natural gum in the silk, which had stuck the threads together on the
arms of the reel. Following the soaking, the skeins are straightened
out and hung across poles in a steam-heated room, as shown in the
accompanying photograph. When the skeins are dry, they are ready for
the first process of manufacturing. The room we now step into is filled
with “winding frames,” each containing two long rows of “swifts,”
from which the silk is wound on to bobbins. The bobbins are large
spools about three inches long. The bobbins filled with silk, as wound
from the skeins, are next placed on pins of the “doubling frames”;
the thread from several bobbins, according to the size of the silk
desired, is passed upward through drop wires on to another bobbin.
Should one of the threads break, the “drop wire” falls, which action
stops the bobbin. By this ingenious device absolute uniformity in the
size of silk is secured. The “doubling frame” is shown in one of the
photographs herewith.

[Illustration: DOUBLING FRAMES--THE SILK THREAD IS MADE UNIFORM.]

The bobbins taken from the “doubling frame” are next placed on a
“spinner.” Driven by an endless belt at the rate of over six thousand
turns a minute, the bobbins revolve, the silk from them being drawn
upward on to another bobbin. This spins the several strands brought
together by the “doubling process” into one thread, the number of turns
depending on the kind of silk--Filo silk being spun quite slack, and
Machine Twist just the reverse.

[Illustration: SPINNING SILK.[2]]

[Illustration: TWISTING SILK.[2]]

A transferring machine combines two or three of these strands; two for
sewing silk and three for machine twist; and the bobbin next goes on
to the “twisting machine”--a machine that is similar to a “spinner,”
but the silk is twisted in the opposite direction from the spinning. To
stand before these machines and watch how rapidly and how accurately
they do the work assigned them is a revelation. No one realizes how
nicely the parts are adjusted. If but one tiny strand breaks that
part of the machinery is stopped by an automatic device which works
instantaneously. After twisting, the silk is stretched by an ingenious
machine called a “water-stretcher.” This smooths and consolidates the
constituent fibers, giving an evenness to the silk not to be obtained
by any other known process. The bobbins are placed in water and the
silk is wound on to the lower of the two copper rolls. From the lower
roll it passes upward to the upper roll, which turns faster than the
lower one, thereby stretching the silk. From the upper roll it passes
again on to a bobbin.

[Illustration: SILK THREADS READY FOR THE WEAVER

WATER STRETCHER--MAKING THE SILK THREAD SMOOTH.]

The dyeing process is a very important one, and upon its success
depends the permanency of the various colors.

Vast tubs, tanks, and kettles surround you on every side, and the
hissing steam seems to spring from all quarters. The “gum” of the silk
is first boiled out by immersion in strong soapsuds for about four
hours. The attendants, standing in heavy “clogs” (big shoes with wooden
soles two inches thick), turn the silk on the sticks at intervals
until the gum is removed. After the silk is dyed it is put into a
“steam finisher,” a device looking like a long, narrow box with a
cover opening on the side, set upright on top of an iron cylinder. The
hanks of silk are placed upon two pins in the steam chest, the cover
fastened, and the live steam rushes in around the silk. This brightens
the silk, giving it the lustrous, glossy appearance.

  The editors are indebted to the Corticelli Silk Mills, Florence,
  Mass., for this story of how silk is made, as well as for permission
  to use their splendid life-like copyrighted photographs of the
  silkworm. Many teachers will be glad to know that they can obtain
  from the Corticelli Silk Mills, at slight expense, specimen cocoons
  and other helps for object lesson teaching.




What Animal Can Leap the Greatest Distance?


The galago, or flying lemur. This singular animal is a native of
the Indian Archipelago. It is from 2 ft. to 3 ft. in length, and is
furnished with a sort of membrane on each side of its body connecting
its limbs with each other; this is extended and acts as a parachute
while taking its long leaps, which measure about 300 ft. in an inclined
plane. The kangaroo can leap with ease a distance of between 60 ft. and
70 ft. and can spring clean over a horse and take fences from 12 ft. to
14 ft. in height. The animals that can leap the greatest distance in
proportion to their size are the flea and the grasshopper, the former
being able to leap over an obstacle five hundred times its own height,
while the grasshopper can leap for a distance measuring 200 times its
own length. The springbok will clear from 30 ft. to 40 ft. at a single
bound. The flying squirrel, in leaping from tree to tree often clears
50 ft. in a leap. This animal also has a broad fold of skin or membrane
connecting its fore and hind legs. A steeplechase horse, called The
Chandler, is reported to have covered 39 ft. in a single leap at
Warwick some years ago. Some species of antelopes can make a leap 36
ft. in length and 10 ft. in height. A lion and a tiger each clear from
18 ft. to over 20 ft. at a bound while springing on their prey. A
salmon often leaps 15 ft. out of the water in ascending the falls of
rivers.




Why Do We Call Voting Balloting?


The term covers all forms of secret voting, as in early times such
votes were determined by balls of different colors deposited in the
same box, or balls of one color placed in various boxes. The Greeks
used shells (ostrakon), whence we derive the term ostracism. In 139
B.C. the Romans voted by tickets. The ballot was first used in America
in 1629, when the Salem Church thus chose a pastor. It was employed in
the Netherlands in the same year, but was not established in England
until 1872, although in Scotland it was used in cases of ostracism in
the 17th century. In 1634 the governor of Massachusetts was elected by
ballot, and the constitutions of Pennsylvania, New Jersey and North
Carolina adopted in 1776, made this method of voting obligatory. The
ballot progressed slowly in the Southern States, Kentucky retaining the
viva voce method until a comparatively recent date. In certain states,
the constitutions stipulate that the legislature shall vote viva voce,
i. e., cast their votes orally. Since 1875 all congressmen have been
elected by ballot. In 1888 the Australian ballot system, which requires
the names of all the candidates for the various offices to be placed
on one large sheet of paper, commonly known as a “blanket” ticket, was
adopted in Louisville, Ky., and some sections of Massachusetts. It is
now in very general use in this country. The voter, in the privacy of
an individual booth, indicates his preference by making a mark opposite
a party emblem or a candidate’s name. This system originated in 1851
with Francis S. Dutton, of South Australia, and Henry George, in a
pamphlet, “English Elections,” published in 1882, was the first to
advocate it in the United States. The first bill enacting it into a law
here was introduced in the Michigan legislature in 1887, but it did not
pass until 1889.




Why Do We Call a Cab a Hansom?


The term is applied usually to a public vehicle, known in England as
a “two-wheeler,” or “Hansom” (from the name of the inventor), and
drawn by one horse. In a hansom cab, the passenger or hirer of the
vehicle sits immediately in rear of the dashboard, the driver sitting
on an elevated perch behind, the reins being passed over the top. The
term cab is sometimes also applied to a four-seated, closed or open
carriage, drawn by one or two horses, the driver sitting in front. The
term is also applied to the covered part of a locomotive, in which the
engineer and fireman have their stations. The word cab is derived from
the cabriolet, a light one-horse carriage, with two seats and a calash
top. In London, England, the cab or hansom was called the “gondola” of
the British metropolis by Disraeli.




Where Did the Name Calico Come From?


A fabric of cotton cloth, the name being derived from the city of
Calicut, in Madras, where it was first manufactured, and in 1631
brought to England by the East India Company. Calico-printing, an
ancient Indian and Chinese art, has become a great industry in this
country and in Britain, as well as in Holland.




Who Made the First Postage Stamp?


The stick on postage stamps so generally used today was invented by
an Englishman James Chalmers in 1834. The English Government passed a
bill calling for uniform postage of One Penny in 1840 and furnished
envelopes bearing stamps printed on them. The people did not like them,
however, and the adhesive stamp invented by Chalmers was substituted.
The first stamps used in America were introduced in 1847. People have,
it seems, always preferred to lick their postage stamps.




How Many Languages Are There?


It is said that there are more than 3,400 languages, including
dialects, in the world. Most of them belong, of course, to savage
or uncivilized people. There are said to be more than 900 languages
used in Asia, almost 600 in Europe, 275 in Africa and more than 1,600
languages and dialects which are American.




What Is the Deepest Mine In the World?


The mine that goes farther down than any other in the world is the rock
salt mine near Berlin, Germany which is 4,175 feet. It is not, however,
straight down but somewhat slanting. The Calumet Copper Mine near Lake
Superior is at a depth in some places of 3,900 feet.

The deepest boring in the world is an artesian well at Potsdam,
Missouri, which is 5,500 feet deep or more than one mile straight down.




What Is Color?


~WHAT PRODUCES THE COLORS WE SEE?~

What is termed the color-sense is the power or ability to distinguish
kinds or varieties of light and their distinctive tints. We owe the
faculty of doing this to the structure of the eye and its elaborate
connecting nerve machinery. The eye in man is specially sensitive to
light, and the sensations we feel through it enables us to distinguish
the different colors. Over 1,000 monochromatic tints are said to
be distinguishable by the retina of the eye, though these numerous
tints are, in the main, merely blendings or combinations of the three
primary color-sensations, the sense of red, of green and of violet.
Each of these colors, it has been demonstrated, is produced by light
of a varying wave length, while white light is only light in which the
primary colors are combined in proper proportion. Colored light, on the
other hand, as Newton proved, may be produced from white light in one
of three ways: First, by refraction in a prism or lens, as observed in
the rainbow; second, by diffraction, as in the blue color of the sky,
or in the tints seen in mother-of-pearl; and third, by absorption,
as in the red color of a brick wall, or in the green of grass--the
white light which falls upon the wall being wholly absorbed, save by
the red, and all that falls upon the grass being absorbed except the
green. In art, color means that combination or modification of tints
which is specially suited to produce a particular or desired effect in
painting; in music, the term denotes a particular interpretation which
illustrates the physical analogy between sound and color.




Where Did the Term Dixie Originate?


The term was applied originally to New York City when slavery existed
there. According to a myth or legend, a person named Dixie owned a
tract of land on Manhattan Island and had a large number of slaves. As
Dixie’s slaves increased beyond the requirements of the plantation,
many were sent to distant parts. Naturally the deported negroes looked
upon their early home as a place of real and abiding happiness, as did
those from the “Ole Virginny” of later days. Hence “Dixie” became the
synonym for a locality where the negroes were happy and contented. In
the South, Dixie is taken to mean the Southern States. There the word
is supposed to have been derived from Mason and Dixon’s line, formerly
dividing the free states from the slave states. It is said to have
first come into use there when Texas joined the Union, and the negroes
sang of it as Dixie. It has been the theme of several popular songs,
notably that of Albert Pike, “Southrons, Hear Your Country Call”; that
of T. M. Cooley, “Away Down South where Grows the Cotton,” and that
of Dan Emmett, the refrain usually containing the word “Dixie” or the
words “Dixie’s Land.” During the Civil War, the tune of “Dixie” was to
the Southern people what “Yankee Doodle” had always been to the people
of the whole Union and what it continued, in war times, to be to the
Northern people, the comic national air. The tune is “catchy” to the
popular ear and it was played by the bands in the Union army during
the war as freely as by those on the other side. During the rejoicing
in Washington over the surrender of Lee at Appomattox, a band played
“Dixie” in front of the White House. President Lincoln began a short
speech, immediately afterward, with the remark, “That tune fairly
belongs to us now; we’ve captured it.”




How Big Is the Earth?


The third planet in order of distance from the sun, Mercury and Venus
being nearer to it. It is in shape a sphere slightly flattened at the
poles and bulged at the equator, hence it is called an oblate spheroid.
The equatorial diameter or axis measures 7,926 miles and 1.041 yds.,
and the polar diameter is 7,899 miles and 1.023 yds. The earth revolves
upon its axis, completing its diurnal or daily revolution in a sidereal
day, which is 3 minutes and 55.9 seconds shorter than a mean solar day.
It revolves around the sun in one sidereal year, which is 365 days, 6
hours, 9 minutes, and 9 seconds. Its orbit or path around the sun is an
ellipse, having the sun in one of the foci. The earth’s mean distance
from the sun is 93,000,000 miles. Its axis is inclined to the plane
of its orbit at an angle of 23° 27′ 12.68″. The circumference at the
equator measures 24,899 miles. The total surface is 196,900,278 sq.
miles, and the solid contents is 260,000,000,000 cubic miles. As we
descend into the earth the temperature rises at the rate of 1° Fahr.
for every 50 ft. At the depth of 10 or 12 miles the earth is red-hot,
and at a depth of 100 miles the temperature is such that at the surface
of the earth it would liquefy all solid matter in the earth.




What Causes Hail?


Hail is the name given to the small masses of ice which fall in
showers, and which are called hailstones. When a hailstone is examined
it is found usually to consist of a central nucleus of compact snow,
surrounded by successive layers of ice and snow. Hail falls chiefly in
Spring and Summer, and often accompanies a thunderstorm. Hailstones
are formed by the gradual rise and fall, through different degrees of
temperature (by the action of windstorms), and they then take on a
covering of ice or frozen snow, according as they are carried through a
region of rain or snow.

With regard to rain, it may be said, in popular language, that under
the influence of solar heat, water is constantly rising into the air by
evaporation from the surface of the sea, lakes, rivers, and the moist
surface of the ground. Of the vapors thus formed the greater part is
returned to the earth as rain. The moisture, originally invisible,
first makes its appearance as cloud, mist or fog; and under certain
atmospheric conditions the condensation proceeds still further until
the moisture falls to the earth as rain. Simply and briefly, then, rain
is caused by the cooling of the air charged with moisture.




Why Does a Human Being Have To Learn to Swim?


It is strange, isn’t it, that almost every animal, excepting man and
possibly the monkey, knows how to swim naturally; others such as birds,
horses, dogs, cows, elephants, can swim as soon as they can move about
alone.

The trouble with man in this connection is that his natural motion is
climbing. He has been a climber ever since he was developed from the
monkey, and when you throw him into the water before he has learned to
swim, he naturally starts to climb and as a climbing motion won’t do,
for swimming, the man will drown.

This climbing motion is as much of an instinct in man and monkeys as
the instinct in dogs which causes him to turn round once or twice
before he lies down just as his forefathers used to do ages ago when,
as wild dogs, they first had to trample the grass before they could lie
down comfortably.




Why Do I Get Cold in a Warm Room?


I suppose you mean the instances when you get cold while in a warm room
even when you are perfectly well. This will happen often when all of
the moisture in the room outside of what is in your body, is evaporated
by the heat in the room. The remedy is, of course, to keep a pan of
water some place in the room as the air has become too dry.

While heat is necessary to evaporate water, the process of evaporation
produces cold. The quicker the evaporation the sharper the cold feeling
produced. Now your body is continually evaporating the water from your
body which comes out in the form of perspiration through the pores of
the skin. This is one of nature’s ways of taking the impurities and
waste out of the body. You know, of course, don’t you, that more than
one-half the waste material which the body expels from the system comes
out through the pores of the skin rather than through the canals.

When the air in the room becomes too dry, the evaporation on the
outside of the body proceeds faster and makes you cold. By keeping
water in some vessel in the room you keep the air of the room from
becoming too dry.




Why Do They Call Them Wisdom Teeth?


The wisdom teeth are the two last molar teeth to grow. They come one
on each side of the jaw and arrive somewhere between the ages of
twenty and twenty-five years. The name is given them because it is
supposed that when a person has developed physically and mentally to
the point where he has secured these last two teeth he has also arrived
at the age of discretion. It does not necessarily mean that one who
has cut his wisdom teeth is wise, but that having lived long enough
to grow these, which complete the full set of teeth, the person has
passed sufficient actual years that, if he has done what he should to
fit himself for life, he should have come by that time at the age of
discretion or wisdom. As a matter of fact these teeth grow at about the
same age in people whether they are wise or not.




What Makes Freckles Come?


Freckles are generally caused by the exposure of unprotected parts of
the body to the sun, but this will not cause freckles on all people.
Only people with certain kinds of sensitive skins freckle. What happens
when freckles are produced in this way is this: The sunlight shining on
the face, neck or arms of anyone who has a tendency to freckle, has a
peculiar action on certain cells of the skin which produces a yellowish
brown coloring pigment, which remains for a time.

Then again the skins of some people are so peculiarly sensitive the
cells develop this kind of coloring matter in almost any kind of light
and such people are, so to speak, apt to be freckled for life.

[Illustration: First successful power-driven aeroplane. The Langley
monoplane with steam engine, which flew over the Potomac River in 1896.]




The Flying Boat


When Did Man First Try to Fly?

~HOW MAN LEARNED TO FLY~

Man’s desire to conquer the air is older than recorded history. When a
kite was flown for the first time the principle of aviation, or dynamic
flight, was uncovered. For centuries man has sought the mechanical
equivalents for the things that keep a kite flying steadily in the
air,--the power that lies in the cord that keeps a kite headed into the
wind; an equivalent for the wind’s own power; an equivalent for the
tail which controls the kite’s lateral and longitudinal balance.

Each separate part of the modern flying machine, or aeroplane, was
worked out long ago, with the exception of the gas engine light enough
and reliable enough to be used for this work. The present generation
knows dynamic flight as a commonplace thing, not because we are so much
more clever than previous generations in designing flying machines,
but because of the development of the modern gasoline or internal
combustion engine.


Who Invented Flying?

No one invented flying, nor did any one man invent all the separate
parts of the flying machine. They are the result of evolution,--of the
combined work and thought of hundreds of men, many of whose names are
unrecorded. To attempt to find the true beginning of the modern flying
machine would be as difficult as attempting to discover who planted
the seed of the tree from which one has gathered a rose. But the tree
from which all the flying machines, or aeroplanes, of today have sprung
undoubtedly is Dr. Samuel Pierpont Langley, third secretary of the
Smithsonian Institution.


Some of the Men Who Helped.

Taking the most conspicuous names of scientists who worked out various
details of the aeroplane during the past century we find that a century
ago Sir George Cayley built a machine on lines very similar to those
accepted today, and he went so far as to foretell the necessity of
developing the internal combustion engine before dynamic flight could
be a success. Mr. F. H. Wenham, in 1866, also built a flying machine
along conventional lines and tried to fly it with a steam engine, which
of course, proved too heavy.

[Illustration: One of Dr. Langley’s first models; a biplane with
flexible wing-tips and twin propellers. 1889.]

~EARLY TYPES OF FLYING MACHINES~

M. A. Penaud, a Frenchman, in experimenting with models, seems to have
been the first to discover the necessity of vertical and horizontal
rudders in maintaining balance. Mr. Horatio Phillips, an Englishman,
discovered, and patented, the use of curved instead of flat surfaces
for the planes. Otto and Gustav Lilienthal are said to have been the
first to attempt to balance aeroplanes by flexing or bending the wings.
Various others, including Messrs. Richard Harte, Boulton, Mouillard,
worked out ideas for balancing machines by the use of auxiliary planes
which could be set at different angles with regard to the line of
flight, thus forcing the machines to different positions by the force
of the air rushing against them.

Dr. Langley, trained in scientific investigation, conducted an
elaborate series of experiments covering many years and costing
thousands of dollars to test and prove the value of the claims of
the earlier investigators. Some things which he thought he was
the first to discover,--such as the effect of the vertical and
horizontal rudders,--he later found had already been proven by others.
Independently he covered the entire field of experiment and after
building hundreds of small models he succeeded, in 1896, in making a
machine weighing several pounds equipped with a very light steam engine
which flew safely as long as the fuel lasted. For his early experiments
Dr. Langley was afforded financial assistance by Mr. William Thaw of
Pittsburg. After the success of his small machines Dr. Langley was
asked to undertake the construction of a large, man-carrying machine,
and Congress voted him $50,000 to carry on the work. A large share of
this was spent on the development of a very light gasoline engine. The
machine finally was completed, but was twice broken through defective
launching apparatus. Congress and Dr. Langley were so ridiculed by the
public press that the machine was temporarily abandoned. Not, however,
until after Dr. Langley had successfully flown a steam driven machine
much larger than many of the racing aeroplanes of today.

But eight years after Dr. Langley’s death, which is said to have been
due to the heart-breaking disappointment he suffered in trying to
demonstrate the large machine, Glenn H. Curtiss, at the request of the
Smithsonian Institution, rebuilt the old Langley machine and succeeded
in making a flight with it at Hammondsport, N. Y., on May 28, 1914.

[Illustration: THE FIRST MAN-CARRYING AEROPLANE

First successful man-carrying aeroplane. Designed by Dr. Langley in
1898; flown by Glenn H. Curtiss at Hammondsport, N. Y., 1914.]

[Illustration: Front view of big Langley machine in 1914.]

While longer flights probably will be made with this machine none
will attain greater importance, because this first flight with it was
sufficient to establish for all time the fact that Dr. Langley built
the first man-carrying machine equipped with a gasoline engine and able
to fly and raise itself with its own power. This was considerably
more than was accomplished by other machines for some time after Dr.
Langley’s death. The Langley machine not only lifted the weight it was
designed to fly with, but also carried pontoon and other fittings,
added by Mr. Curtiss to make flight from the water possible, which
added 340 pounds to the original weight of the machine.

[Illustration: THE MACHINE WITH WHICH BLERIOT FLEW IN EUROPE

Copy of early Langley model with which Bleriot made first circular
flight in Europe.]

The connection between Dr. Langley’s work and present machines is now
very easy to trace, though not obvious until 1911, when the Smithsonian
Institution published memoirs written by Dr. Langley in 1897, and
some memoirs of Mr. Octave Chanute, a French engineer who resided in
Chicago, and who forms one of the main connecting links. The chain
is practically completed by notes left by the late Lieut. Thomas
Selfridge, U. S. A., America’s first martyr to aviation.

Dr. Langley’s knowledge is represented in modern aviation by three
distinct lines. The central and most direct line is through Dr.
Alexander Graham Bell, inventor of the telephone, to the Aerial
Experiment Association, and thence to Mr. Glenn H. Curtiss, and finds
its expression in what is known as the Curtiss type of machines.

Another line is that carried by a Mr. A. M. Herring to Mr. Chanute and
by him transmitted to Mr. Wilbur Wright, finding expression in the
Wright type of biplane.

The third line is that leading to the modern monoplane school; M.
Bleriot having first copied in toto the tandem monoplane form,
generally known as the Langley type, and later, with the development of
better gasoline engines, developing into the monoplane as known today.

With the exception of M. Bleriot it is doubtful if the others fully
realized the source of their inspiration,--not to call it information.

Dr. Bell was interested in Dr. Langley’s work for more than ten years
before Dr. Langley gave up. He observed many of the trials, and his
reports of the first successful flights are incorporated in the
official publications of the Smithsonian Institution. Dr. Bell began
some independent experiments, but following Dr. Langley’s death he
formed the Aerial Experiment Association, to carry on the work left by
Dr. Langley. The members of this organization were, Mr. Curtiss, at
that time the most successful builder of light motors; Lieut. Thomas
H. Selfridge, U. S. A.; Mr. J. A. D. McCurdy and Mr. F. W. Baldwin, two
young Canadian engineers. Mrs. Bell financed the project, furnishing
the sum of $35,000 for the experiments.

~WHAT TWO BROTHERS ACCOMPLISHED FOR FLYING~

The Wright Brothers, for Wilbur Wright was joined by his brother
Orville in the experiments, were the first to reap success from the
seeds of Dr. Langley’s sowing. Mr. Chanute had been experimenting
with a biplane form of motorless glider with little success, because
of lack of means for balancing the machines in the air, until he was
joined by a former employe of Dr. Langley. He appears to have imparted
to Mr. Chanute the secret of the stabilizing effect of the Penaud
tail, or combination of vertical and horizontal rudders. Thereafter
hundreds of successful gliding flights were made with the Chanute
biplane, though Chanute seems not to have grasped the full significance
of the rudders,--though it was well understood by Dr. Langley. To
the Chanute machine, as described to him, Mr. Wright added first the
idea of flexing or warping the wings, after the fashion set by the
Lilienthals. He found, however, as Dr. Langley had found years before,
that in attempting to correct lateral balance in this way caused the
aeroplane to swerve to such an extent that the fixed vertical rudder,
as originally employed, did not correct the upsetting tendency that was
developed. Mr. Wright then arranged his rudder in such a way that when
the wing was warped the rudder turned in a way to offset the swerve.
This combination was patented all over the world and has resulted in
much complicated litigation.

To this machine the Wright Brothers added a gasoline motor in December,
1903, and with it made numerous flights during 1904-5. Their claims
were not generally credited however until a later date for their
experiments had been conducted with considerable secrecy, and during
1906, 1907 and until late in 1908 they did no more flying.

In the meantime M. Bleriot had made a copy of one of the early Langley
tandem monoplane models and made some fairly successful flights with it
in Europe. Later, as gasoline motors developed in power for weight, he
reduced the rear surface until the modern monoplane evolved.

While Bleriot was working in Europe, Dr. Bell’s Aerial Experiment
Association in America was evolving still another type of machine, and
the members of the association made the first successful public flights
in America. Mr. Curtiss won the Scientific American Trophy for the
first time on July 4th, 1908, by a straightaway flight of more than a
kilometer. The balancing system employed by the A. E. A. differed from
that employed by the Wrights and by Bleriot in that small auxiliary
planes took the place of warping planes for righting the machine. This
they claimed to be a superior method, first, because it eliminated the
use of the rudder as being absolutely essential to the balance of the
machine; second, because it enabled them to make the main planes rigid
throughout, and consequently stronger than the flexible planes.

There are several other names that must be mentioned in connection
with the early history of successful flight; these are the Frenchmen,
Messrs. Henri Farman, Maurice Farman, the brothers Voisin, and Santos
Dumont. These produced some of the first notably successful aeroplanes
in Europe but seem to have discovered nothing which has had any marked
effect upon the later development of flying machines. M. Farman adopted
the auxiliary planes used by the A. E. A. and modified them to suit his
ideas.

~WONDERFUL RECORDS OF AEROPLANES~

Volumes could be, in fact, have been written about the exploits of
the first demonstrators of the practical heavier-than-air flying
machines,--of the crossing of the English Channel by Bleriot, of the
flights by Wilbur Wright at Rheims, France; of Mr. Curtiss’ winning of
the first Gordon Bennet International speed trophy and his flight down
the Hudson from Albany to New York; of Orville Wright’s flight at Fort
Meyer, and the death of Lieut. Selfridge who was flying with him. The
barest record of these interesting accomplishments would fill volumes.
Of the aeroplane proper it is enough to say here that since 1908 its
development has been too rapid for accurate recording. In strength, in
speed, in reliability, in size and carrying capacity, it has developed
at a remarkable rate. At this writing the speed record is about 130
miles per hour; the duration record is more than 24 hours, non-stop;
the distance record is some 1,300 miles in one day; the altitude record
some 26,000 feet. New records succeed the old ones with such rapidity
that probably before this can be printed all these present records will
have been greatly eclipsed.

[Illustration:

  AEROPLANE “RED WING” HAMMONDSPORT, N.Y.

  FIRST AMERICAN PUBLIC FLIGHT, MAR 12 1908]

[Illustration: The biplane in which G. H. Curtiss flew from Albany to
New York in 1910.]

Meantime the aeroplane has developed greatly in other directions. In
flying over land with the early types of machines many fatal accidents
occurred, particularly to the fliers who gave exhibitions everywhere
during 1909, 1910 and 1911. A majority of these accidents were
indirectly due to the fact that a very smooth surface is required for
landing a fragile machine running at high speed. The obvious expedient
was to develop machines capable of rising from and alighting upon the
water.

[Illustration: SOME FAMOUS FOREIGN MONOPLANES

A modern German monoplane.]

[Illustration: The machine in which Bleriot crossed the English Channel
in 1909. A modified Langley type.]

[Illustration: Rolland Garros and monoplane in which he flew across the
Mediterranean Sea in 1914.]

~THE WONDERFUL FLYING BOAT~

During the winter of 1910 and 1911 Mr. Curtiss, who had continued
independent experiments upon the disbandment of the Aerial Experiment
Association, succeeded in producing the first machine to safely leave
and return to the water. For the development and demonstration of
this type of flying machine he was awarded the Aero Club of America
Trophy, and when during 1912 he produced still another type of water
flying machine, the Curtiss Flying Boat, he was again awarded the Aero
Club Trophy and also voted a Langley Medal by the directors of the
Smithsonian Institution.

[Illustration: Different views of flying boat.]

Not until the development of the flying boat did the general public
begin to take a participative interest in aviation, but as soon as the
comparative safety of this type of machine became apparent the new
sport began to be taken up rapidly both in this country and in Europe.
The experiences of naval fliers and amateurs alike went to show that
water flying offered not only the fastest and most comfortable mode
of rapid travel, but also the safest, for during 1913 several hundred
thousand miles were flown by navy aviators and amateur enthusiasts in
Curtiss water flying machines without a single serious accident.

What aviation will mean to future generations,--even to this generation
in the course of a few years,--it would be foolhardy to try to guess.
Mr. Rodman Wanamaker already has agreed to furnish the financial
support for Mr. Curtiss’ attempt to build a machine to fly across the
Atlantic Ocean, from America to Europe. If the venture is successful it
is expected the crossing will be made in a fraction of the time taken
by the fastest Transatlantic liners. The discovery of new metals and
new manufacturing methods will certainly result in the development of
light motors that may be relied upon to run for days without stopping,
and automatically stable aeroplanes seem to be not far away. This will
result in overland flight as safe and sure as we now enjoy over water.

[Illustration: INSIDE OF A MODERN FLYING BOAT

Interior arrangement of modern flying boat, showing fuel tank and
instrument board.]

[Illustration: Six-passenger flying boat hull. This machine will fly
1,000 miles without stopping for fuel.]

[Illustration: FUN IN A FLYING BOAT

Flying at speed of a mile a minute.]

[Illustration: Monoplane flying boat, built for R. V. Morris.]

[Illustration: In a flying boat on pleasure bent.]

~GREATEST PRESENT VALUE OF AEROPLANE~

At present the greatest value of the aeroplane seems to be for
military reconnaissance and all the great powers are striving their
utmost to secure supremacy in the air. France, Germany, Russia and
England have to date spent millions in developing aeroplane fleets.
Only the government of the United States has failed as yet to
appreciate the military significance of the flying machine. If the
relative aeronautical strength of the world’s nations were represented
alphabetically the U. S. would naturally scarce have to change its
initial, U being slightly in advance of Z which would stand for
Zululand. But even with its modest equipment the navy fliers of the
United States proved the great worth of the aeroplane and the flying
boat, when during the recent trouble in Mexico the air scouts gathered
in a few minutes information that could only have been secured by days
of cavalry scouting before the advent of the flying machine. Indeed,
the name of Lieut. P. N. L. Bellinger, the most able of the naval
fliers at Vera Cruz, has figured more prominently in the despatches
from the front than that of any other officer connected with the
expedition.

Flying seems certain in the very near future to take its place as the
fastest, safest and most comfortable mode of conveyance. The flying
boat will render quickly accessible the vast country lying along the
great rivers of South America, Africa, and Australia; it will bridge
the great lakes and the oceans; bring near together the islands of the
Pacific and Indian oceans. It will make imperative, because of the
speed with which distances will be traversed, of a language common
to all peoples; and treble man’s life without extending his years by
making it possible to see and do three times as much in the same length
of time.

~TEN YEARS OF FLYING~

Ten years ago on that day, December 17, 1913, Wilbur and Orville Wright
made four flights on the coast of North Carolina near Roanoke Island,
a spot historic in America’s history as the site of the first English
settlement in the Western Hemisphere.

[Illustration: Flying over military post in Curtiss biplane.]

The first flight started from level ground against a 27-mile wind.
After a run of 40 feet on a monorail track, the machine lifted and
covered a distance of 120 feet over the ground in 12 seconds. It had
a speed through the air of a little over 45 feet per second, and the
flight, if made in calm air, would have covered a distance of over 540
feet.

Altogether four flights were made on the 17th. The first and third by
Orville Wright, the second and fourth by Wilbur Wright. The last flight
was the longest, covering a distance of 852 feet over the ground in 59
seconds. After the fourth flight, a gust of wind struck the machine
standing on the ground and rolled it over, injuring it to an extent
that made further flights with it impossible for that year.

[Illustration:

  1900

  1901

  1902

  1905
  1904

  1903]

The gliding experiments of Lilienthal in 1896 led the Wright Brothers
to become interested in flight. The next four years were spent in
reading and theorizing. In the Fall of 1900 practical experiments were
begun with a man-carrying glider. These experiments were carried on
from the sand hills near Kitty Hawk, North Carolina. The first glider
was without a tail, the lateral equilibrium and the right and left
steering were obtained by warping of the main surfaces. A flexible
forward elevator was used. This machine was flown as a kite with and
without operator, and several glides were made with it.

A second machine was designed of larger size, and many glides were
made with it in 1901. This machine was similar to the one of 1900 but
had slightly deeper curved surfaces. Experiments with this machine
demonstrated the inaccuracy of all the recognized tables of air
pressures, upon which its design had been based.

In 1902 a third glider was constructed, based upon tables of air
pressures made by the Wright Brothers themselves. The lateral control
was maintained by warping surfaces, and a vertical rear rudder operated
in conjunction with the surfaces. Nearly a thousand gliding flights
were made with this machine.

In 1903, the Wright Brothers designed a machine to be driven with a
motor. They also designed and built their own motor. This had four
horizontal cylinders, 4 in. by 4 in., and developed 12 h.p. Two
propellers, turning in opposite directions, were driven by chains from
the engine. After many delays the machine was finally ready and was
flown on the 17th of December, 1903, as related above.

In the Spring of 1904, power flights were continued near Dayton with a
machine similar to the one flown in 1903, but slightly heavier.

The first complete circle was accomplished on the 20th of September,
1904, in a flight covering a distance of about one mile. Altogether 105
flights were attempted during the year, the longest of which were two
of five minutes each, covering a distance of about three miles. All of
the flights were started from a monorail.

After September a derrick and a falling weight were used to assist in
launching the machine.

[Illustration:

  1908-9

  1910

  1910

  MODEL R, 1910]

~INTERESTING GOVERNMENTS IN FLYING MACHINES~

It was not till 1908 that the Wright Brothers found purchasers for
their invention. In that year they made a contract to furnish one
machine to the Signal Corps of the United States Army and to sell the
rights to their invention in France to a French company. In both cases
they agreed to carry a passenger in addition to the operator, fuel
sufficient for a flight of 100 miles, and to make a speed of 40 miles
an hour.

After making some preliminary practice flights at their old experiment
grounds near Kitty Hawk in May, 1908, Wilbur Wright went to France to
give demonstrations before the French Syndicate and Orville Wright to
Washington to deliver the machine to the United States Signal Corps.
The machines used by Wilbur Wright had been standing in bond in the
warehouse at Havre since August of the year before. Owing to damage
done to the machine in shipment, it was not ready for the official
demonstrations until late in the year.

Meanwhile Orville Wright in September, 1908, started demonstrations
of the machine contracted for by the United States Government. On the
9th he made two flights, one of 57 minutes, and the other one hour
and 2 minutes, world’s records. On the 10th and 11th, these records
were increased and on the 12th a flight of 1 hour and 15 minutes was
made. On the 17th, the tests were terminated by an accident in which
Lieutenant Selfridge met his death and Mr. Wright was severely injured,
so that he was not able to complete the tests until the following year.

Four days after the accident, on the 21st of September, Wilbur Wright
made a flight of 1 hour and 31 minutes at Le Mans, France, which record
he improved several times during the following months, and on the 31st
of December, won the Michelin Trophy by a flight, in which he remained
in the air 2 hours and 24 minutes.




Where Is the Wind When It Is Not Blowing?


The answer is, of course, that there isn’t any wind then. To understand
this perfectly we must study a little and find out what wind is. In
plain words it is nothing more than moving air.

If you make a hole in the bottom of a pail of water the water will run
out slowly. If you knock the whole bottom out of the pail filled with
water, the water will rush out before you know it.

That is about what happens to make the wind. The air is constantly
full of air currents, like the currents you can see in a river. Down
the middle of the river you may notice a softly-flowing current going
straight. Along the shores there will be little side currents going
in all directions, and you may find some little whirlpools. That is
exactly what we should see in the air if we could see air currents.




Where Does the Wind Begin?


The movement of these currents of air leaves many pockets of space
where there is no air, and when one of these is uncovered the air
rushes in and creates a wind in doing so. These air currents are
continually pressing against each other to get some place else. They
change their direction according to the pressure that is being applied
to them. Sometimes the pressure will be very light in one part of the
air, many miles away perhaps, and then the air in another part, which
is under great pressure, will rush with great force into the part where
the pressure is light, and thus form a big wind. When the pressure
stops the wind stops.

We have probably felt the wind which comes out of the valve of the
automobile tire when the cap is taken off to pump up the tire. It is a
real wind that comes out. The reason is that the air in the tube of the
tire is under great pressure, and when the opportunity is given to get
where the pressure is light it starts for that place with a rush and
comes out of the valve a real wind.




What Causes the Wind’s Whistle?


The whistle of the wind is caused very much like the whistle you make
with your mouth or the noise made by the steam escaping through the
spout of the kettle. You do not hear the wind whistle when you are
out in it. You can hear it when you are in the house and the wind is
blowing hard. When the wind blows against the house it tries to get
in through all the crevices, under the cracks of the doors, down the
chimneys, wherever it finds an opening. And whenever it starts through
an opening that is too small for it, it makes a noise like the steam
coming out of the spout of the kettle, provided the opening is of a
certain shape.

Not all the noises made by the wind, however, are made in this way. The
wind in blowing against things makes them vibrate like the strings of a
piano or violin, and when things vibrate, as we have already seen, they
produce sound waves, which, when they strike our ears, produce sounds
of various kinds. The wind even on ordinary days makes the telegraph
and telephone wires hum, as you can prove to yourself by placing your
ear against a telegraph or telephone pole, and whenever the wind makes
anything vibrate, a great many queer sounds are produced, which often
frighten us more than they should.




Why Does the Air Never Get Used Up?


Simply because it is constantly being replenished. The three gases,
oxygen, nitrogen and carbonic acid gas, which are found in the air
about us, are constantly being used up. All living animal creatures are
at all times taking oxygen out of the air to live on. Certain microbes
are using up quantities of the nitrogen all the time, and the plants
live on the carbonic acid gas. But while these different kinds of life
between them use up the air, they give back something also. The plants
give off oxygen. The bodies of the animals and plants when they die
decompose, and as they are full of nitrogen, that is given back to the
air in that way, and then all living creatures are always throwing off
carbonic acid gas through their lungs, and thus everything that is
taken out of the air is put back again. The plants live on carbonic
acid gas, and give us back oxygen. The living creatures live on oxygen
and give off carbonic acid gas, and when they die their bodies put
back in the air the nitrogen which the microbes take out, and so,
consumption and production are about equal all the time.




Why Can’t We See Air?


We cannot see air because it has no color and is perfectly transparent.
If at times it appears that there is color in the air it is not the
air you see, but some little particles of various substances in it.
Sometimes you think when you look off toward a range of mountains or
hills, for instance, that the air is blue. You know the grass and trees
on the mountains are green, so it cannot be they that have turned blue,
and so you think the air is blue. But it is only the sunlight reflected
to your eyes from the little particles of dirt and other substances
which fill the air at all times which makes the blue that you see, and
not the air.

Pure air is a mixture of gases without any color and is perfectly
transparent. Air is nearly entirely composed of a gas called
nitrogen--the remainder being oxygen with a little water and carbonic
acid gas, which latter is thrown off in breathing. This is, however,
but a very small percentage.

Air has been and still can be reduced to a liquid state, and with
the use of it in this form many seemingly wonderful things can be
done, which are interesting to look at, but have not as yet become
commercially practical.




Why Does Thunder Always Come After the Lightning?


This occurs simply because lightning or light travels so much more
quickly than sound. Light travels at the rate of 186,000 miles per
second, and sound travels only at the rate of 1090 feet per second when
the temperature is at 32 degrees. Now, the thunder and lightning come
at the same time and place in the air, but the light travels so much
faster that you see the lightning often quite some seconds before you
hear the thunder. In fact, you can tell quite accurately how far away
from you the flash of lightning and clap of thunder are by taking a
watch and noting the number of seconds which elapse between the flash
of the lightning and the time when you hear the roll of the thunder.
If as much as five seconds elapse you can figure that it was about a
mile away from you, since sound travels only about 1100 feet per second
and there are 5280 feet in a mile. When the thunder and lightning come
close together you may know that it is near by, and when they come at
the same time you may be sure it is very close. When, therefore, you
see the lightning and then have to wait several seconds for the noise
of the thunder, you may rest easy about the lightning hurting you,
because you know then it is too far away to harm you, and when it is so
close that the lightning and thunder come simultaneously, there is no
use being afraid, because if you were to be struck you would have been
struck at the same instant or before you would have had time to notice
that the lightning and thunder come together.




How Big Is the Sun?


It is very difficult to gain a clear idea of how very large the sun
really is. We know from the scientists who have measured it with their
accurate measuring instruments that it is 865,000 miles through it, and
that at its largest part it is 2,722,000 miles around. Now, you can
see why I said it is very difficult to get a clear conception of the
sun’s size. A mile is quite a long distance to walk on a hot day. Now,
the earth is 8000 miles through. If there were a tunnel right through
the earth, like the subway, and you started to walk it, it would take
you 83¹⁄₃ days if you walked day and night without stopping to rest or
eat, if you kept going at the rate of four miles every hour. This would
be a long, hot walk, for, of course, the inside of the earth is hot,
as we have already learned. It would take an automobile, going at the
rate of 40 miles an hour night and day, about nine days to make the
trip through such a subway from one side of the earth to the other.
That makes it look like a pretty big old earth, doesn’t it? But let us
see what would happen if we started to do the same thing on the sun.
The sun is 865,000 miles through. If you were to walk through a similar
tunnel on the sun at four miles per hour it would take you 20 years,
not counting the stops, and an automobile going 40 miles an hour day
and night would take two years and a half to make the trip one way.

The sun is ninety million miles from the earth and an automobile
travelling at the rate of forty miles per hour day and night on a
straight road, without stopping, would be 257 years in getting there.

When we stop to think of how big the bulk of the sun is it is
altogether beyond us. We have a general idea that our earth is a pretty
large affair as worlds go, and yet we cannot conceive how much the
bulk of the earth amounts to. Still, the sun is so large that it could
contain a million worlds like our own.




How Hot Is the Sun?


We think the sun is pretty hot in summer when the thermometer goes
up to 90 degrees in the shade or out. We begin to get sunburned long
before it reaches that high. But right on the sun’s surface it is
between 10,000 and 15,000 degrees hot. That is, of course, a degree
of heat which we cannot conceive. How much hotter still it is on the
inside of the sun we don’t as yet know. It must be awfully hot there.




Why Is It Warm in Summer?


It is warm in summer because at that season of the year the heat rays
of the sun strike our part of the earth through less air. The blanket
of air which surrounds the earth is very much in comparison as to
thickness like the peeling of an orange and surrounds the earth in
just the same way. If you stick a pin straight into an unpeeled orange
you only have to stick it in a little way before you reach the juicy
part of the orange, but if you stick the pin in at an angle the pin
will travel a much longer ways through pure peeling before it strikes
the juicy part. Now, then, in summer the rays of the sun come down
to us straight through the peeling of air, and less of the heat is
lost by contact with the air, and that makes it warmer in summer. The
explanation also accounts for your next question.




Why Is It Cold in Winter?


In winter the heat rays of the sun strike at our part of the earth at
the angle at which you stick the pin into the orange when you wish to
make it travel through the most peeling. In winter the rays strike
the earth at such an angle that a great deal of the heat is lost in
travelling through the air, because they have to come through so much
more of the air. Of course, the sun’s rays strike some part of the
earth straight down through the peeling of air at all times, and at the
equator this occurs all the year round, so it is always summer there,
while at the North and South Poles the rays always strike the earth at
the greatest possible angle, and it is always very cold winter there.
In between, when it is neither hot nor cold, we have spring and fall,
due to the fact that the rays come down at an angle, but not so great
an angle.




Why Have We Five Fingers on Each Hand and Five Toes on Each Foot?


All animals, it seems, from a study of nature were started with ten
fingers and ten toes, the fingers originally having been the toes of
the fore legs. In a good many cases the environment in which animals
have lived has caused a change in the formation of the ends of the
limbs as well as in the limbs themselves. The horse, for instance, has
developed into a one toe or one finger animal, while a cow is a two
finger animal. The hen has only three toes on each foot and a part of
another. But if we go back into the history and examine how the horses’
foot used to look we will find that he originally had five toes. The
same is true of the cow and also the hen. Something happened to cause
the change, for the rule of five fingers and five toes on the end of
each limb has been universal. If you examine a chicken in a shell just
before it is ready to come out, you can distinctly count five toes on
each foot and at the ends of the wings you will see five little points,
which under other conditions would develop into fingers, perhaps.
Some of these toes of the new-born chicken do not develop. It can be
accepted as a rule that creatures were intended in the original plan to
have five fingers on each hand and five toes on each foot, making our
count of tens, which is the world’s basis for counting, and has always
been.




Why Do We Have Finger Nails?


Finger nails and toe nails are only another phase of the development
of man from the animal that originally walked on four feet. Animals
that walk on all fours use the finger and toe coverings which in man
is the nail, to scratch in the ground, to attack enemies, and to climb
with, and our nails of the present day are what the development of man
into a civilized being has changed them to. At that, there are still
uses for finger nails and toe nails, or man in his changing to a higher
plane would have found a way to develop away from them. They are useful
to-day in making our fingers and toes firm at the end, and enable us
to pick up things more easily. The time may come when man will have
neither finger nails nor toe nails.




Why Are Our Fingers of Different Lengths?


There is no known reason why our fingers should be of different lengths
to-day; in fact, it is thought by some people that the hand would
be stronger if the fingers were all of the same length. Certainly,
however, the hands would not then be so beautiful, and it might not be
so useful. The human hand to-day is perhaps the most versatile thing
in the world. You can do more things with the hand than with any other
thing in the world. The probability is that the shape of the hand
to-day and the length of the fingers are the result of the different
things the human being has called upon the hand to do during man’s
development up to the present time.

We must go back to the time, however, when man walked on fours, for
that is probably the real explanation. Originally man’s fingers were
of different lengths because all four-footed animals had the same
peculiarities. The shape and length of the toes and their arrangement
were the ideal arrangement for giving the proper balance and support
to the body, and in moving about and in climbing produced the best toe
hold.




Why Does It Hurt When I Cut My Finger?


It hurts when you cut your finger, or, rather, where you cut it,
because the place you have cut is exposed to the oxygen in the air, and
as soon as it is so exposed a chemical action begins to take place,
just as when you cut an apple and lay it aside you come back and find
the cut surface all turned brown. If the apple could feel it would
hurt also, because the chemical action is much the same. The apple has
a skin which protects its inside from the oxygen in the air, and you
have also a skin which protects you from the oxygen as long as it is
unbroken.

What happens, of course, is this: When you cut your finger you sever
the tiny little veins and nerves which are in your finger. They are
spread all over your body like a net-work under the skin, close to the
surface in most places. The nerves when cut send a quick message to the
brain, with which they are connected, telling that they are damaged,
and the brain calls on the heart and other functions to get busy and
repair the damage along the line. There may be some hurt while this
process of repairing is going on, but the principal part of your hurt,
outside of what we call your feelings, is due to the fact that the
inside of you is thus exposed to the chemical action of the air. Then I
can hear you say next:




Why Don’t My Hair Hurt When It Is Being Cut?


It does not hurt to cut anything that has no nerves. There are no
nerves in the hair which the barber cuts. If he pulls out a hair it
hurts, because the root of the hair has nerves, which telegraph notice
of the damage to the brain. When a dentist takes out or kills the nerve
in your tooth you cannot have any more toothache in that tooth, because
there is no nerve there to send the message to the brain. You can cut
your finger nails without feeling pain, because they have no nerves at
the ends, but underneath, where they join the skin of the finger, there
are a great many nerves, and it hurts very much to bruise the nails at
that location.




Of What Use Is My Hair?


~WHY WE HAVE HAIR~

Your hair is a relic of the days when the entire body was covered with
hair, just like some animals to-day, to protect the body from the heat,
cold and wet. Man has, however, for so long a time worn clothes over
most of his body that the need of the hair to protect him from these
elements has all but disappeared, and so also has the hair, excepting
in such places as the top of the head and face and other exposed
parts. If you were to go out into the woods without clothes and live
a long time your body would probably again become covered with hairs.
The time is coming, however, it is believed, when human beings will
have no hair at all on their bodies. You have hair on your head, but
if you were to wear a hat or cap all the time you would soon be bald.
Hair is of no use to us to-day excepting to adorn our bodies and add
to our appearance. This it seems to do to-day, probably because we
are accustomed to seeing it, and will make no difference in our looks
relatively if the time comes when we have no hair at all.




Why Does My Hair Stand On End When I Am Frightened?


It does this under certain conditions, because there is a little
muscle down at the root of each hair that will make each hair stand
up straight when this muscle pulls a certain way. It is difficult to
say just how these muscles are caused to act in this way when we are
frightened. We know that when thoroughly frightened our hair will
sometimes stand straight up, and we know that it is this muscle at the
root of each hair that makes it possible, but why it is that a big
scare will make this muscle act this way we do not as yet know.




What Makes Some People Bald?


The chief cause of baldness is the lack of care of the hair. It is as
necessary for the roots of the hair to have a free circulation of
the blood and that the hair itself should have plenty of air as it is
necessary for the brain to have a good circulation. A great many men
become bald through wearing their hats most of the time. The hat pulled
down tight over the head presses against the scalp and interferes with
the circulation of the blood in the scalp. Then, also, many hats do
not have any means of ventilation, and that keeps the pure air away
from the hair. The hair then becomes sick and dies, just as flowers
wilt if you keep them away from the air. You will notice that women
do not become bald so easily. One reason is that even when the women
wear large hats, as they often do, there is plenty of room for the air
to circulate through the hair, even when the hat is on, and women’s
hats are not pulled down tightly on the scalp. Therefore, they do not
press on the arteries and veins in the scalp and interfere with the
circulation of the blood. Another reason why women do not become bald
is that the hair of women has long been their “crowning glory”; a man
likes to see a fine head of hair on a woman, and as women have long
tried to please men in every possible way, they take better care of
their hair than men do, because they like to have the men consider it
beautiful.




What Makes Some Things in the Same Room Colder than Others?


The objects in a room which has been kept at a given even temperature
of heat will be all the same temperature, because heat spreads from one
thing to another equally.

Still, if you put your hands on various objects in such a room some
of them will feel colder than others. You touch the tiling of the
fireplace and that will feel cool to you. On the other hand, the
upholstered furniture will feel quite warm. The piano keys feel cool,
while the wood of the piano and case is warm. The difference is due to
the fact that heat or cold will run through some objects more quickly
than through others. It will run through the tiling on the hearth
and the piano keys more quickly than through the upholstering on the
furniture or the wood of the piano case. When you touch a thing with
your finger you supply some of the heat of your body to the object
through your finger. If the object is the tiling on the hearth or
the keys of the piano the heat runs through it quickly and you get a
cold impression in your finger. On the other hand, if you touch the
upholstery on the furniture, through which the heat runs slowly, you
get a warm feeling for the very same reason. Thus, anything which
carries the heat away from our contact quickly we call a cold feeling
object, and if the object touched does not carry the heat away so
quickly we call it a warm feeling object.




Why Does the Hair Grow After the Body Stops Growing?


The hair on our bodies is one of the things that is continually wearing
or falling away, and since, like the skin, it is necessary to protect
certain portions of the body, the hair keeps on growing long after the
grown up period has arrived. The skin is a very necessary protection
of the whole body, but is constantly being worn away, and is all the
time being replaced. Your hair falls out when it is not healthy. Unless
proper care is given to it, it will fall out and not grow in again, and
then we become bald.




Will People All Be Bald Sometime?


There is a theory that before many years have passed human beings
will lose all of the hairs which now grow on different parts of their
bodies, due to the fact that we wear so much clothing and keep so much
of our bodies away from the sunlight. If that time comes we shall have
a hairless race of men and women.




THE STORY IN A LUMP OF SUGAR


[Illustration: PREPARING THE GROUND.--PLOWING AND HARROWING WITH A
CATERPILLAR ENGINE.

Sugar beets require deep plowing, ten to fourteen inches, or twice the
usual depth. When using horses, farmers are inclined not to plow deeply
enough to secure maximum results, and some of the factories have put
in power plows which turn six furrows and harrow the land at the same
time. They plow and harrow the land of beet farmers for $2.50 per acre,
which is about one-half of what it costs the farmers to plow equally
deep with horses. The traction engines also are used for hauling train
wagon loads of beets to the factory. In some localities farmers are
banding together and purchasing engines for plowing and hauling beets.
The outfit illustrated above costs about $4,500.]

[Illustration: DRILLING THE SEED.

Beets are drilled in rows, usually eighteen inches apart, 18 to 25
pounds of seed being drilled to each acre. Practically all the beet
seed used in America is grown in Europe, principally in Germany, but it
has been demonstrated that superior seed can be produced in the United
States. Sugar-beet seed growing requires five years of the utmost
skill, care and patience, from the planting of the original seed to
the maturing of the commercial crop which is sold to the trade. The
factories contract for their seed for three to five years in advance,
sell it to farmers at cost price, and deduct the amount from the
payment for beets.]

[Illustration: HOW THE BEETS ARE GROWN

BLOCKING AND THINNING.

When the beets are up and show the third leaf they should be “thinned.”
Unless thinned at the proper time the pulling up of the superfluous
beetlets injures the roots of the remaining ones. Scientific
experiments in Germany, where all other conditions were identical,
showed that one acre thinned at the proper time yielded 15 tons; the
next acre, thinned a week later, yielded 13¹⁄₂ tons; the third acre,
thinned still a week later, yielded 10¹⁄₂ tons; and the fourth acre,
thinned three weeks after the first, yielded 7¹⁄₂ tons.

The men in the foreground are “blocking” the beets, leaving a bunch of
them every eight inches. Those in the rear are “thinning,” or pulling
up the superfluous beetlets, leaving one in a place, eight inches
apart.]

[Illustration: READY FOR THE HARVEST.

This field of beets yielded 20 tons to the acre. Ex-Secretary of
Agriculture James Wilson is convinced that when American farmers become
expert in beet culture they will average to produce more than 20 tons
per acre because of the superiority of our soils. The ideal factory
beet weighs about two pounds, and a perfect “stand” of such beets, one
every eight inches, in rows eighteen inches apart, would yield 43¹⁄₃
tons per acre. The present average yield in the United States is about
10 tons per acre, while the hitherto “worn-out soils” of Germany yield
14 tons per acre, or 40% more than is secured from our “virgin soils.”]

[Illustration: HUGE BINS TO HOLD THE BEETS AT FACTORY

TOPPING THE BEETS.

After the beets are plowed out they are topped or cut off by hand and
the tops are fed to stock, for which purpose they are worth $3.00 per
acre. They are topped just below the crown and the factories require
that they be so topped as to remove any portion which grew above the
ground, as such portion of the beet contains but a small percentage of
sugar. The beet will grow in length, and, if as a result of shallow
plowing or coming in contact with a rock it cannot grow downward, it
will grow upward and out of the ground, thus necessitating a deeper
topping and consequent loss to the farmer.]

[Illustration: DUMPING CARS AT FACTORY WITH HYDRAULIC JACK.

Beets arriving at the factory by rail from receiving stations either
are stored in bins until needed or are floated directly to the beet
washers. If to be used at once, they are dumped, as shown above, and
slide directly into a cement flume filled with warm water, which has
been pumped to its upper end, and is flowing in the direction of the
beet end of the factory. In whatever manner they may be received, they
first are weighed, and as they are dumped, a basket is held under them
to catch a fair sample of both beets and the loose dirt, which the
car or wagon contains. These samples, properly tagged, are conveyed
to the beet laboratory, where they are washed, and trimmed if not
properly topped, and the difference in the weight of the sample beets
as received and their weight when washed is called the “tare.” Whatever
percentage this amounts to is applied to and deducted from the weight
of the car or wagon load. A sample of these beets then is tested by the
polariscope for its sugar content and its purity; farmers often being
paid a stipulated price per ton for a beet of a given sugar content and
25 to 33¹⁄₃ cents per ton additional for each extra degree of sugar
which they contain. The tare rooms and the beet-testing laboratories
are open to any one, and in some localities the farmers’ associations
employ experts to tare and analyze each sample of beets.]

[Illustration: MILLIONS OF BUSHELS OF BEETS

FACTORY BEET BINS FILLED TO CAPACITY.

As they arrive by rail from receiving stations, or by team, or traction
engines from the farm, beets are stored in bins or sheds, the capacity
of which ranges from 6000 to 35,000 tons per factory, depending upon
location and general climatic conditions.

The bins are V shaped, about 3 feet wide at the bottom, 20 to 30 feet
at the top, and they are 20 to 30 feet high. As beets are needed,
beginning at one end of the bin the loose three-foot planks at the
bottom are removed one at a time, and with hooks attached to long poles
the beets are rolled into the flume or cement channel below, in which
they are floated into the factory. This is not only to save labor,
but to loosen up the dirt which attaches to the beets, thus partially
washing them. The water which is used in the flumes is warm water from
the factory.]

[Illustration: TYPICAL AMERICAN BEET SUGAR FACTORY.

These factories cost from half a million to three million dollars.
They consume from 500 to 3,000 tons of beets per day, and during the
“campaign,” which usually lasts about three months, will produce from
12 to 75 million pounds of granulated sugar. There are 73 of these
factories, located in 16 States, from Ohio to California. During the
operating season they give employment to from 400 to 1000 men each.]

[Illustration: WASHING THE SUGAR BEETS

CHEMICAL LABORATORY.

In a beet-sugar factory each set of apparatus for performing a given
process is termed a “station.” In the chemical laboratory the juices
and products from each station are tested hourly to check up the
correctness of the work and to determine the losses of sugar in each
process in the factory.]

[Illustration: CIRCULAR DIFFUSION BATTERY.

After being floated in from the sheds the beets are elevated from the
flume to a washer, where they are given an additional washing before
being sliced. From the washer they are elevated and dropped into an
automatic scale of a capacity of 700 to 1500 pounds. From the scale
they pass to the slicers, where with triangular knives they are cut
into long, slender slices, which look something like “shoestring”
potatoes. These slices drop through the upright chute seen at the right
side of the picture, and are packed tightly into cylindrical vessels
holding from two to six tons each; the battery consisting of eight to
twelve vessels arranged either in a straight line or in circular form.
Warm water is run into these slices, and coaxes out the sugar as it
passes from one vessel to the succeeding ones. After passing through
the entire series of vessels the water has become rich in sugar, of
which it contains from 12 to 15 per cent, depending upon the richness
of the beets. It then is drawn off and is called diffusion juice or
raw juice. This is carefully measured into tanks and recorded. As this
juice is drawn off the vessel over which the water started is emptied
of the slices from the bottom, the exhaust slices containing in the
neighborhood of ¹⁄₄ to ¹⁄₃ per cent of sugar. These slices are carried
out from the factory in the form of pulp and fed to stock, as explained
later.]

[Illustration: HOW THE SUGAR IS TAKEN FROM THE BEET

CARBONATATION AND SULPHUR STATION.

Warm raw juice is drawn into the carbonatation tanks and treated with
about 10 per cent milk of lime--about like ordinary whitewash. This
lime throws out impurities, sterilizes the juice and removes coloring
matter. Carbonic acid gas from the lime kiln is forced through the
lime juice in the tank, throwing out the excess of lime, converting it
into a carbonate of lime or chalk. Tests are taken here by the station
operator to show when the process is finished.]

[Illustration: FILTER PRESSES.

From the carbonatation tanks the juice is pumped or forced through
filter presses consisting of iron frames so covered with cloth that the
juice passes through the cloth as a clear liquid, leaving the lime and
impurities precipitated by it, in the frame, in the form of a cake.
This cake, after washing, is dropped from the presses and conveyed out
of the factory. It contains from one to two per cent of its weight
in sugar, which constitutes one of the large losses of the process.
It also contains organic matter, phosphate and potash, besides the
carbonate of lime, which makes it an excellent fertilizer, all of which
is used in Europe on the farm, but so far to too small an extent in
America.]

[Illustration: EVAPORATING THE WATER FROM THE SUGAR

EVAPORATORS.

After a second, and sometimes a third carbonatation and filtration, the
juice is carried to the evaporators, commonly called the “effects,”
usually four (4) large air-tight vessels furnished with heating tubes
running from 3000 to 7000 square feet in each vessel. A partial vacuum
is maintained in these evaporators which makes the juice boil out at a
low temperature, thus preventing discoloration, and to a large degree
the destruction of sugar which will come about by high temperature.
There always is, however, some unavoidable loss of sugar in this
apparatus. The juice passes along copper pipes from first to last
vessel, becoming thicker as it does so. It comes into the first vessel
at 10% to 12% sugar and is pumped out of the last one so thick that it
contains about 50% of sugar.]

[Illustration: VACUUM PANS.

After a careful filtration, the juice that comes from the evaporators,
and is called thick juice, is pumped to large tanks high up in the
building, and from these is drawn into vacuum pans. These are large
cylindrical vessels from 10 to 15 feet in diameter and from 15 to 25
feet high, with conical top and bottom, built air-tight. Around the
inner circumference they are furnished with 4- to 6-inch copper coils,
which have a heating surface of 800 to 2000 square feet. Exhaust steam
is used in the evaporators, live steam in the pans, the juice in both
being boiled in a vacuum to prevent discoloration and reduce losses.

After considerable thickening by this evaporation, minute crystals
begin to form. When sufficient of these have formed, fresh juice is
drawn in and the crystals grow, the operator governing the size of
the crystals to suit the trade. If small crystals be desired, a large
quantity of juice is admitted at the outset, while if large crystals
are desired, a small quantity of juice first is admitted, and, as it
boils to crystals, fresh juice gradually is added to the pan, and the
crystals are built up to the desired size. The operator of this pan,
known as the “sugar boiler,” is one of the must important men in the
factory. The water furnished the condensers of these vacuum pans and
the evaporator goes to the beet sheds and is used for floating in the
beets. It amounts to from 3,000,000 to 8,000,000 gallons every 24
hours, depending upon the size of the factory, and must be very pure.]

[Illustration: HOW SUGAR IS GRANULATED

FRONT VIEW OF CENTRIFUGAL MACHINES.

The mass of crystals with syrup around them and containing about 8 per
cent to 10 per cent of water is let out of the vacuum pan into a large
open vessel called a mixer, beneath which are the centrifugal machines.
These are suspended brass drums perforated with holes and lined with a
fine screen. They are made to revolve about 1000 times to a minute, and
the crystal mass of sugar rises up the side like water in a whirling
bucket. The centrifugals force the syrup out through the screen holes,
leaving the white crystals of sugar in a thick layer on the inner
surface. These are washed with a spray of pure warm water and then are
ready for the dryer.]

[Illustration: SUGAR GRANULATOR OR DRYER.

The damp white crystals from the centrifugal machine are conveyed
to horizontal revolving drums about 25 feet long by 5 to 6 feet
in diameter. These drums are furnished with paddles on the inside
circumference, the paddles picking the sugar up and dropping it in
showers as the drum revolves. Warm dry air is drawn through and takes
the moisture out of the sugar, which now is ready to be put in bags or
barrels for the market.]

[Illustration: BY-PRODUCTS OF THE SUGAR BEET

CRYSTALLIZERS.

The syrup that was thrown off from the crystals in the centrifugal
machines is taken back to the vacuum pan, evaporated in the same
manner as previously described, and from the vacuum pan goes into the
crystallizers to carry the process of crystallization as far as it will
go. These contain from 1000 to 1600 cubic feet of the crystallized
mass which remains in them from 36 to 72 hours, during which time it
is kept in constant motion by a set of slowly revolving paddles, or
arms, to facilitate further crystallization. From the crystallizers it
goes to the centrifugal machines, where the syrup is separated from the
crystals as before. The crystals are remelted and go in with the thick
juice for white sugar. The syrup, still containing a large amount of
sugar, goes out to be sold as cattle feed or to an Osmose or Steffens
process, where a portion of the remaining sugar may be recovered. This
lost syrup constitutes the largest loss in the entire process. It
contains all the impurities of the beet juice not removed by the lime.
These impurities prevent more than one and one-half times their weight
of sugar from crystalizing, and make what is called molasses.]

[Illustration: A SEA OF BEET PULP.

For a century the high feeding value of sugar-beet pulp has been
recognized in Europe, but until a few years ago millions of tons of
this valuable by-product rotted about American beet-sugar factories, as
shown above, because American farmers could not be made to believe it
possessed sufficient value to pay for hauling it back to the farm.]

[Illustration: MACHINE THAT FILLS, WEIGHS AND SEWS THE BAGS OF SUGAR

SACKING ROOM.--SHOWING AUTOMATIC SCALES AND SEWING MACHINE.

After the moisture has been thoroughly removed in the granulators
or dryers, the sugar drops directly to the sacking room through
a chute, at the lower end of which the top of the double bag is
attached. The sugar flows directly into the sack, the flow being cut
off automatically with each 100 pounds, when an endless belt conveyor
passes the upright sack past the sewing machine at the proper speed and
the product is sealed ready for storage or shipment.

While it requires from 400 to 1000 men to man a factory, not a human
hand has touched either beets or product since the beets were topped in
the field, and at no stage of the operation could flies or vermin or
filth come in contact with the product, which from the beginning has
been subjected to continuous high temperatures.]

  Pictures herewith by courtesy of United States Beet Sugar Industry.




How Can We Smell Things?


You do not need to be told what organ of the body we use in exercising
the sense of smell. You can prove that easily to yourself by getting
the nose within range of a distasteful smell.

We do not use all of the nose to smell with, and the nose is useful to
us in other ways besides this. We use the nose a great deal in the act
of respiration or breathing, and it is also useful in helping us to
make sounds, form words, and, though you may not have known it, helps
our sense of taste.

We smell things by means of the olfactory nerves which are located
within the nose. The entire interior surface of the nose is covered
with a membrane. The ends of olfactory nerves, or the nerves which give
us the sensation of smell, are in this membrane, and the air, which is
filled with the odor of things we smell, passes over this membrane, and
thus the ends of the nerves feel the odor and cause sensation of smell
in the brain. The nerves of smell do not, however, go all through this
membrane.

There are other nerves in the nose, however, besides those which give
us the sensation of smell. These are also very sensitive and serve to
make the nose exercise other functions when the inside of the nose is
hurt or tickled. When a foreign substance, one of the many smaller
particles which are constantly floating in the air, gets into the
membrane in the nose, it irritates these nerves and often causes us
to sneeze, which is only nature’s effort to drive out this foreign
substance and clean out the nose. Smell is one of the lesser of the
five senses which we possess. It is one of what has been called the
chemical senses. The sense of smell does not act at any great distance.
This sense could be made of more value to us if we developed it. Some
people have a more highly developed sense of smell than others. The
lower animals have a much keener sense of smell than people. A great
many of them can follow a trail for miles merely by the smell of the
foot-prints, and it is said that a deer will note the presence of man
or any other animal that may subject him to danger even when miles
away, the odor being carried to him through the air.




How Do We Taste Things?


The sense of taste is closely associated with the sense of smell. In
fact we do a good deal of what we think is tasting by using our sense
of smell. A cold in the nose will sometimes destroy almost altogether
the taste of food, so that there is a very close connection between the
sense of taste and the sense of smell.

The sense of taste comes to us through the tongue, which is the
principal organ of taste. The remainder of our sense of taste lies in
the surface of the palate and in the throat. As in the case of the
other senses, the sensation of taste is given us through nerves, the
ends of which are all through those parts of the tongue, the palate
and the throat, which contribute to this sense. More nerves of taste
are located in the back part of the tongue than on the front, and it
is said that when you have to swallow a bad dose of medicine it won’t
taste so much if you put it on the front part of your tongue and then
swallow, because there are so few tasting nerves there. The extreme tip
of the tongue, however, is very thickly covered with the ends of the
taste nerves. In like manner one could have the front end of the tongue
cut off and still retain most of the sense of taste.

Now, in order to produce the sensation of taste, the substance to be
tasted must come in contact with something which mixes with it and
causes the sensation of taste. This is what happens when we taste
anything. The juices or liquids which are caused to flow when anything
is put into the mouth act on the substances which enter and give the
taste nerves a chance to taste them. Really the nerves of taste are so
placed in the mouth as to be regular guards or inspectors of what shall
go into the stomach. You can see how well they are arranged. In the tip
of the tongue quite a few of them; in the back part of the tongue a
great many nerves, for from there the food goes into the throat, which
delivers it to the stomach; then those in the palate and in the throat.
They are arranged so that the taste nerves have ample opportunity to
test what comes in and to give warning to the brain of what is being
sent to the stomach. Sometimes the things that come into the mouth
are so distasteful to the nerves of taste that they refuse to hand it
over to the stomach, but instead cause the distasteful substance to be
thrown out again immediately.

It is said that a good rule to follow in eating would be to swallow
only such things as are pleasing to the sense of taste. On this
principle many children would decide to eat nothing but candy, but do
you know, if you tried that, the continuous tasting of sweets by our
sense of taste nerves would cause them to repel further insertion of
candy after a while. You know that too much of a good thing is bad for
you, and that is what makes you feel badly when you have eaten too much
of one thing.




What Happens When We See?


~HOW WE SEE THINGS~

Of course, it is the eyes with which we see things. When we think of
the things with which we see, we think only of eyes, which give us our
sense of vision, but there are certain forms of animal life which have
no eyes but which have what are called eye spots or eye points, which
are sensitive to light and which are merely spots. These eye spots
may be located in any part of the body, and are often found in great
numbers on the same body. These rude eyes are, however, not real eyes.
They are, as has already been said, sensitive to light, but are found
only in some of the very low forms of animal life which live in the
water. A real eye is an organ in which the parts are so arranged that
optical images may be formed.

As animal life becomes developed to a higher scale, the parts which
contain the making of real eyes become more distinct although, of
course, the eyes themselves are not so highly developed as in man. One
of the first kinds of life which has eyes with a definite structural
character are the worms, snails, etc., though their sense of vision is
more or less dim.

When we come to the family of mollusks, however, low down in the scale
of life though they are, we find them to possess eyes which enable them
to see almost as well as animals which have a backbone, although this
kind of eyes is constructed in a very different manner than the eyes
of vertebrate animals referred to. As we ascend the scale of animal
life in the study of eyes, we come next to the crustaceous, which is an
important division of animal life that embraces the crabs and lobsters,
shrimps, crawfish, and insects such as sand-hoppers, beach-fleas,
wood-lice, fish-lice, barnacles. The eyes of such animals are quite
developed, but the number that each will have varies. Some have only a
single eye and others two, four, six or eight, but only certain kinds
of this class of life have more than two eyes. The spiders generally
have the most.

In vertebrates, which is the class of animal life to which we belong,
the number of eyes is almost always two and no more. The eyes are
formed in special sockets in the skull, which are called eye sockets
or orbits. This arrangement of placing them in a socket is of great
advantage because the eye is thus protected from chance of injury
except from one direction--the front. These animals have also eyelids,
eyebrows and eyelashes, which serve as a further protection to the eyes.

The principal parts of the eye are arranged in a globe-like ball called
the eyeball. This eyeball is movable in the socket under control of
various muscles. The eyeball is almost surrounded by a membrane which
is opaque in most parts, but very transparent at the front. This
transparent portion of the surrounding membrane is called the cornea,
and is quite hard. This is the outside coat of the eye. The second
coat of membrane consists of parts of various names and contains the
iris. The third coat is the retina, which is the end of the optic nerve
entering the eye full from behind and expanded into a membrane which
spreads out over the second coat.

The retina or optic nerve receives optical impressions focused upon it
by the crystalline lens. These impressions are carried along the optic
nerve to the brain, and the brain then receives the sensation of seeing
the image. The eyeball is hollow, and its three surrounding coats
form what is practically the same as the interior of a camera. The
crystalline lens of the eye acts the same as the lens in the camera.
This crystalline lens is suspended within the eyeball right in front of
the transparent opening in the front of the eyeball, and when the rays
of light strike this lens it focuses them on the retina, which is the
same as the film in your camera.




Why Can We Hear?


We can hear because nature has provided us with a very wonderful organ
called the ear and which catches the sound waves that come through the
air into the ear and make a part of the ear vibrate.

In man and mammals the ear is generally found on the outside of the
body, but the principal part of the ear is located within the skull.
What we call ears are only the funnel-shaped extensions on the outside
of the head which are not so very important so far as hearing is
concerned, because they only help the real ear to hear more easily. The
outside of the ear gathers in the sound waves and, because it is much
larger than the little hole which takes the sounds in to the real ear,
we can detect more sounds by having this funnel-shaped arrangement on
the outside.

The inside of the ear contains an eardrum or tympanum which is
separated from the outside part of the ear by a membrane. Behind this
eardrum is the real hearing part of the ear in a labyrinth containing
the nerves of hearing.

Now, when a sound wave strikes the membrane which hangs over the
opening before the eardrum, the membrane vibrates and transmits the
sound wave through the eardrum into the inner ear which contains the
ends of the nerves by which we hear. These nerves, on receiving the
sensation, transmit it to the brain which thus records the impression
of sounds.

As we descend the scale of animal life from the mammals downward, the
ear becomes a more and more simple organ. In the vertebrates which
are not mammals, there is no external ear at all, and we find great
simplifications of the ear the lower down in the scale we go.




What Is a Totem Pole For?


Before people had individual names, the savage people who lived in
clans or tribes referred to themselves in the name of some natural
object, usually an animal which they assumed as the name or emblem
of the clan or tribe. These names never applied to one individual
more than another, but only to the clan or tribe, so that everyone
in a tribe which had taken the “wolf” for its emblem was known as
“Wolf.” Later on they began to distinguish individuals by giving them
additional names characteristic of the individual, such as “Lonely
Wolf,” “Growling Wolf,” or other names. The name of this animal was
then the emblem of one tribe. They, therefore, placed this emblem upon
their bodies, their clothes, utensils, etc. Through this, these emblems
also became at times idols of worship and so they erected poles upon
which their emblems were engraved. The word totem is a North American
Indian word meaning “family token.” The tribes called themselves after
animals from which they believed themselves descended.




Where Does a Flower Get Its Perfume?


The perfume or smell of the flower comes from within the plant itself.
The perfume arises from an oil which the plant makes, and just as there
are many kinds of flowers, so almost every flower has a different
smell. Of course, flowers belonging to the same family or species are
likely to develop different smells. The oils produced are what are
known as the volatile oils, which means “flying oils,” because, if
extracted from the flower and placed in a bottle and the cork left out,
they will vanish into the air. Without this quality we could not, of
course, smell them at all.




Why Do Flowers Have Perfumes?


Man uses these oils to provide himself with perfumes, but the plant or
flower has another purpose than this. The perfume is not made for man’s
use, but for the use of the plant itself. In the plant and flower world
the smell of the plant which is in the flower is a part of the scheme
whereby plants reproduce themselves.

Every plant in order to reproduce itself must produce a seed. The
flowers are in most cases the advance agent of the coming seed. Each
flower produces within itself a little powder called the pollen, but as
plants are like people--also male and female--they are dependent upon
each other for the production of a perfect seed. Some of the pollen
from the male plant must be mixed with the pollen of the female plant
before a perfect seed results.




How Do Flowers Produce Seeds?


Naturally, the nearest male plant to a female plant may be quite some
distance off. How, then, is the pollen from the male plant to mix with
the pollen of the female plant? In some cases it is the wind which
blows the pollen powder from one to the other, and this thus leaves the
development of a perfect seed from a perfect flower open to chance. In
the case of perfumed flowers, however, which are mostly low-growing
plants, the wind cannot be depended upon. So nature gives to such
plants the power to make the perfumed oil and the busy bee does the
rest. The perfume being a flying oil rises up into the air and attracts
the bee. He is gathering honey and visits in turn all the flowers to
which he is attracted. He lights on a male flower and gathers in his
honey, and incidentally acquires on his legs, without intending to do
so, some of the pollen of the male flower. Then he flies about to the
next flower, and to others, and sooner or later he will come across a
female flower of the same kind as that from which he secured the pollen
on his legs. When he thus enters the female flower, the pollen on his
legs mixes with the pollen of the same kind of the female flower, and
quite unintentionally the bee helps thus to make the perfect seed. It
is not a part of a bee’s business to do this carrying. It only happens
that he does this in connection with his regular business of gathering
honey. It is a wonderful thing which may be noted here that the pollen
from a male of any flower will not mix with the pollen of the female of
any other kind of flower, but that the same kinds only have attractions
for each other. Flowers are given these attractive perfumes in order
that they may attract the bees and other insects in this way. The
plants or flowers which grow closest to the ground have generally the
strongest and most far-reaching smells. This is so that they will not
be overlooked.




Why Are Leaves Not All the Same Shape?


Leaves are of different shapes because they belong to different
families of plants or trees. They are a good deal like people in this
respect. Hardly two people in the world look exactly alike, but there
is a distinct family resemblance in members of the same family. It is
difficult to say just what happens inside the tree to determine the
shape of the leaf and that causes them to possess different shapes
from others. The shape of the leaf is a mark of identification of the
family to which the tree or plant belongs, just as you can tell from a
dog’s ears and from other characteristics what his breeding has been.
In the case of plants and trees however it is quite probable that the
shape and texture of the leaves has been developed as the result of
the conditions under which the plant grows. A plant or tree throws
off oxygen and takes in carbonic acid gas through the surface of the
leaves. To thrive and be healthy it must secure just the proper amount
of this food and as the quantity of food taken in depends upon the
amount of surface exposed through the leaves, each particular tree or
plant has developed in its own direction in this respect until this
feature of their structures has been adjusted properly to their needs.
It is a good deal like the radiation of heat in your home.




Why Are Some Radiators Longer Than Others?


When the plumber gets ready to put in the radiators in the home he
figures the cubic measurements of the room and then puts in a radiator,
the outside surface of whose pipes, is in the right proportion to throw
off sufficient heat to fill the room or heat all the air in the room.
It requires a certain number of square inches of radiator surface to
heat each cubic foot of air space and a good plumber can figure this
to a nicety. If he puts in a radiator however that has not sufficient
number of square inches on the outside of the pipes, the room will
not be heated properly. In the same way, the trees, require that
their leaves have a certain amount of square inches of surface space
in proportion to the size of the tree, to enable them to do what is
required of them and this is arranged by nature so that the trees grow
naturally, and no doubt the shape of the leaves has something to do
with this.




What Makes Roses Red?


All roses are not red. Some are white and others pink or of still
another color. The color of the rose, and in fact the color of all
flowers is due to the way they absorb and reflect the sunlight. In the
case of the red rose, the something in the plant that determines the
color, absorbs all the other colors in the sunlight and reflects the
pure red rays and that makes the color of the red rose. You cannot see
the color of any flower when it is perfectly dark. That is because they
have no color of their own, but only the colors which they reflect when
in the sunlight or some other light. The question of colors is more
fully explained in another part of the book.




Why Do Plants and Trees Grow Up Instead of Down?


As a matter of fact plants and trees do grow downward as well as up.
There is a part of each called the root whose business it is to grow
down and take certain things necessary to the life of the tree out of
the ground. But the part we see above the ground and which is the part
we generally think of only when we think of plants or trees.

The tree or plant, in order to grow properly, and eventually produce
flowers and perfect seeds, must have sunshine and carbonic acid gas,
and it is the business of the leaves and other parts above the ground
to get these out of the air for the good of the plant or tree. So they
start to grow toward the sun. It is easy to prove how a plant will turn
toward the light. Take notice of the plants in the flower pots at home.
Set one of them on the window sill inside the window where the sun can
shine on it and notice how quickly the leaves and branches will be bent
over against the window pane. Turn it completely around then so that
the plant leans away from the sunlight and watch it for a day or two.
Before long you will find that it has not only straightened itself
completely out but started to lean toward the window glass again so
as to get as near the sun as possible. Most plants, if kept where the
sunlight cannot touch them, will die. The sunlight is a necessary part
of their lives.




What Becomes of the Plants and Flowers in Winter?


A great many, in fact the large percentage of plants, live only during
one season. This kind of plant actually dies completely after, in the
natural course of growth and flowering, it has produced its seed which
is the method by which such plants are reproduced. Other plants only
appear to die in the winter. Parts of them, such as the leaves and
flowers actually die, but the roots and stalks of such plants do not
die in winter. The part that represents the life in them goes to sleep
and lies dormant until the light and warmth of summer bring forth the
leaves and flowers again.

The flowers, however, always die and the same flowers never appear
again but others just like them appear in their places.

Even in hot countries where there is no winter, the plants must go
through a period of rest or sleep, although this change is not so
marked in plants which grow in these hot countries.




How Can Some Plants Climb a Smooth Wall?


To get at the answer to this question, we should pick out one kind
of plant like the creeping ivy vine. If we examine same as it climbs
a brick wall, we find that it sends out little shoots which attach
themselves around the little rough places in the bricks of the wall
which, if examined under a microscope are quite large apparently--at
least they are large enough for the tiny creepers of the ivy to hold on
to. Of course, if there were only one little “shoot” to reach out and
take hold of the rough spots in the wall, the vine could not cling to
the wall, but the vine puts out a great many of these shoots--which it
would perhaps be best to call “clingers” and as each helps a little to
hold on, the great number all holding on together enable a quite heavy
vine to hang on to an apparently smooth wall.

Some vines have actually the ability to send out little suckers which
are made on the same principle as the boys’ sucker (a circular piece of
leather with string attached to the middle with which a boy can pick up
stones) and such plants can cling to and climb up an almost perfectly
smooth wall.




What Are the Thorns on Roses and Other Plants Good For?


The thorns of roses and other plants which have thorns originally grew
for the purpose of enabling the plants to fasten themselves on to
other things thus helping them to climb. Many plants with thorns are
permitted to grow now in places where they can use their thorns for
climbing but many others with thorns are cut down by the gardener to
make the plants shapely and to make them produce more flowers and less
branches, but they keep on growing their thorns just the same.




Do Plants Breathe?


Yes, indeed, plants do breathe. To breathe is just as important to the
life of a plant as it is to a boy or girl. Plants do not have lungs
like boys and girls and grown up people, but they find it necessary to
breathe. You know, of course, that fishes breathe, but they haven’t any
lungs either, even though they belong to the animal kingdom. Fishes
do not, however, breathe the air in the same form as we do because
they must use the air which they find in the water. That is why we say
fishes drown when on the land. They cannot breathe air in the form in
which we are able to use it any more than people can breathe the air in
the water.

Breathing, however, is necessary to all living things and the gas which
we take in when breathing is oxygen. There is oxygen in the water as
well as in the air. Things which live in the air take their oxygen out
of the air and things which live in the water get their oxygen out of
the water. For this purpose it is necessary for plants and animals that
live under the water to have a breathing apparatus especially adapted
for getting oxygen out of the water.




What Happens When Breathing Occurs?


The act of breathing consists really of two actions. Taking something
into the body and expelling something. Every living thing inhales and
expels in breathing. We take in oxygen and expel it again but when it
comes out it has added something to it and the combination or result is
carbonic acid gas--so we take in oxygen and expel carbonic acid gas.




How Do Plants Breathe?


The lungs of a plant, or what the plant breathes with corresponding to
our lungs, are located in the leaves of the plant. Under a magnifying
glass we can see the lungs of the leaf quite clearly. In addition to
this we know that plants breathe, because if we put them in a vacuum
where there is no air they die very quickly. The plant needs air or
it will suffocate just as any animal will suffocate under similar
conditions. Plants, however, do not make use of the oxygen as they
find it in the air. They live on the carbon which they find in the
air mixed with oxygen. What happens then is this. The plants take in
through their lungs in the leaves carbonic acid gas from which they
take the carbon and use it as food, and throw off the oxygen which
they cannot use. Human beings and other animals take the oxygen into
their lungs and use it and expel carbonic acid gas. The result is that
each kind of life is dependent upon the other. If it were not for the
plant life, men and other animals would find it difficult perhaps to
find sufficient oxygen in the air to keep them alive, and if it were
not for the carbonic acid gas which the animals throw off, plants and
other vegetable life would have great difficulty in finding sufficient
carbonic acid gas to go around.




Why Do Plants Need Sunlight?


Most plants, if placed where no light from the sun can reach them, will
die very quickly. To prove that a plant needs the sunlight we have
only to place it in a dark corner of the cellar and notice how soon it
dies. In fact if it were not for sunlight there would be no life on
earth at all. The plant or tree drinks in sunlight through the surface
of the leaves. In fact the ability to take in sunlight constitutes the
real life of the tree or plant. Leaves grow thin and flat in order
that as much surface as possible may be exposed to the sunlight. If
a leaf were curled up like a hoop only a part of the outside surface
would be exposed to the sunlight and the amount of life that a leaf
could supply to the rest of the tree would be much less. The leaf is so
constructed that when the sunlight strikes down upon its green surface,
it changes the carbonic acid gas which it drinks in, into its elements,
i.e., it takes out the carbon which goes into the body of the plant and
combining with other food and water supplied by the roots causes the
plant or tree to grow and then returns the oxygen part of the carbonic
acid gas to the air.




Why Does Milk Turn Sour?


The milk turns sour because a little microbe, known as the milk microbe
gets into it, and being very fond of the sugar which is in the milk,
turns this sugar into an acid.

If we could keep milk entirely away from the air after the cow is
milked, it would not turn sour, but as soon as it is exposed to the air
these microbes which are constantly in the air, drop into the milk.
They are alive, although invisible to the naked eye. If when they drop
into the milk it is warm enough for them to get in their work so to
speak, they fall upon the sugar in the milk and turn it into the acid.
Their attempt to sour the milk can be overcome by keeping the milk at a
low temperature in the refrigerator, but as soon as the milk is taken
out of the refrigerator and left out long enough to become warm, the
microbe begins to work and the milk cannot be made sweet again. If the
milk is boiled as soon or shortly after the cow is milked, the sugar in
the milk is changed in such a way that the microbe cannot feed upon it.

[Illustration: A PERSIAN RUG WEAVER AT WORK.[3]]

  [3] Pictures and descriptions by courtesy of Hartford Carpet Co.




The Story in a Rug


What Are Carpets and Rugs Made Of?

The choicest wool of the world is used in the manufacture of carpet.
In order to give satisfactory service carpet must be made of wool that
is of a tough quality and has a long fiber. Such wool is not produced
in America, and the markets of the distant lands that supply it are
practically exhausted to supply the American manufacturers. Most of the
wool used comes from Northern Russia, Siberia and China. It is shipped
in bales. When it arrives at the mill there is much to be done before
the wool is ready for any process of manufacturing.


How Long Have People Used Carpets?

The art of weaving stands foremost among the ancient industries. It
came into being in the sunrise lands of the East where color has
endless charm and variety and where figure is made to serve the purpose
of fact and fancy. The art of weaving rugs is older than Egyptian
civilization. Stone carvings made when Egypt was yet unborn were
reproduced in rugs.

At what period the loom was first used is impossible to tell. An
ancient Jewish legend claims that Naamah, daughter of Tubal-Cain, was
the inventor of the process of weaving threads into cloth. There are
other indications that the ancient Hebrews were the first weavers.
Mythology also tells of beautiful maidens weaving exquisite patterns
for the gods. Most of us are familiar with the story of Jason who set
sail on the Argo in search of the Golden Fleece, arrived at the kingdom
of Aeetes, won the hand of Medea, the daughter of Aeetes, who eloped
with him after he had secured the coveted fleece.

The first hands busy at the weaving craft undoubtedly were those of
women. Chaldean gossip, repeated in history relates that Sardanphulees,
an ancient Greek king, was often seen in woman’s garb carding purple
wool from which his wives wrought rugs for floor coverings for the
palace. Homer shows Helen of Troy setting the tale of her people’s
war in the woof of her web, and also tells with Virgil of rugs that
were laid under the thrones of kings or upon chariot horses. Ancient
Hindu hymns show that these people made their textile fabrics studies
of great beauty. The woman in the Proverbs of Solomon says: “I have
woven my bed with cords; I have covered it with painted tapestry from
Egypt.” One learns from the writings of Pliny of the large money value
of rugs in ancient times. He wrote at length of a vast rug displayed at
a banquet of Ptolemy Philadelphius, the value of which was placed at a
fabulous sum.

A later writer tells of the love of Cleopatra for rich rugs and
tapestries that were woven in her palace or in the countries to the
East. On the occasions of her meeting with Cæsar and Antony, the
Egyptian queen enveloped herself in a superb rug which she had woven
especially for the purpose of showing her renowned beauty to the best
advantage. Akhar, emperor of Hindostan, spread a knowledge of the art
of weaving throughout India.

The earlier phases of the art of weaving may be traced through the
land of the Pharaohs to Northern Africa, Southwestern Asia, and
finally into the dawn of the Aryan civilization. The loom has not been
materially changed, and it may be seen to-day as it was in the time
when the priests of Heliopolis decorated the shrines of their gods with
magnificent carpets and when Delilah wove the hair of Samson with her
web and fastened it with a wooden pin. The ancient weavers attained
high artistic standards in their fabrics. Pliny tells of Babylonian
couch covers that had all the beauty of paintings and sold for great
fortunes to the ancient Asiatic kings.

In all ages fine rugs have been used for religious purposes. Early
writings describe the use of rugs on the holy cars of pilgrimage to
Mecca, at the tomb of the prophet at Medinah and throughout the mosques
of the Orient. The abbot Egelric gave to the church at Croyland, before
the year 892, two large rugs to be laid before the high altar on great
festivals. At later periods rugs were used for similar purposes in the
cathedrals of Southern Europe.

The Oriental people ever have been devoted to symbols and naturally
wove them into their fabrics. Their textiles were made to reproduce
mythological stories in which the fauna and flora of a country figured
prominently. There was the symbolism of form, color and animal life,
of trees and flowers, of faith, and earthly and heavenly existence.
The symbols were made to illustrate the conflict between light and
darkness, the evolution of life, the decay of death and the immortality
that awaits the blessed in paradise.


What Do the Designs in Rugs Mean?

Since many of the figures of ancient rug-weaving are retained in modern
rug designs, the following list of meanings of ancient Oriental symbols
used in rug-weaving may be interesting as a key to the stories that are
said to appear in many rugs of Oriental design:

  Asp--intelligence
  Bat--duration
  Bee--immortality
  Beetle--earthly life
  Blossom--life
  Boat--serene spirit
  Butterfly--soil
  Crescent--celestial virgin
  Crocodile--deity
  Dove--love
  Eagle--creation
  Egg--life
  Feather--truth
  Goose--child
  Lizard--wisdom
  Palm tree--immortality
  Sail of vessel--breath
  Wheel--deity
  Lion--power
  Ass--humility
  Butterfly--beneficence of summer
  Jug--knowledge
  Ox--patience
  Hawk--power
  Lotus--the sun
  Pine-cone--fire
  Zigzag--water
  Leopard--fame
  Sword--force
  Serpent--desire
  Bird--spirit
  Owl--wisdom
  Pig--kindness

Such are the traditions that the makers of modern rugs must live up to.
The art of the centuries has been revealed in the rugs of many nations,
and the rug-maker of to-day must uphold the standards of an art that
undoubtedly takes rank with the great arts. Where a valuable painting
goes into the home of one millionaire, thousands of rugs made from
an original design of unquestioned art and beauty go into homes the
country over to give warmth, comfort and beauty, delighting housewives
and imparting a sense of coziness and elegance.

According to students of the art of weaving, the perfection of this
art was attained about the sixteenth century, after many centuries of
slow growth. Since then weaving as an art has been broadened and given
a wider scope by means of processes invented for a cheaper production
of rugs in all the beauty of their original designs. But there also has
developed a modern school of rug and carpet designing that in itself
represents no mean standard of art. Many of the less expensive grades
of American rugs and carpets, for example, are of designs created by
artists of this modern school of weaving designs whose work is of a
high degree of artistic excellence.

[Illustration: HOW OUR GRANDMOTHERS MADE RAG CARPETS

MAKING THE OLD RAG CARPET.]

A quarter of a century ago many homes had rugs woven by the housewives
with their spinning-wheels, or no floor coverings, except crude
cloths made of rags. These homes, of course, were those of families
in moderate circumstances, which to-day can have their attractive and
comfort-giving rugs of the less expensive grades of tapestry carpet,
Axminster or of the various other grades of carpet manufactured at a
range of prices within the financial reach of people of modest means.

It is only a step from the ancient weaving of rugs, with all the color,
glamor and romance that attached to rug-weaving in the ancient days, to
the manufacture of rugs in America to-day. There is no romance attached
to the making of rugs and carpets in America, except the romance of
industrial achievement; but the American rug-maker is as careful of the
quality and beauty of his product as was the ancient weaver, and the
best standards of ancient weaving have been realized in the manufacture
of rugs and carpets in America to-day.


Why Did the Ancients Make Rugs?

It is only a rug, several yards of woven threads, a design that few
can understand--a simple thing, to be sure; yet what a lot of history
and memories and traditions it carries! Merely a strip of carpet, with
strange figures, beautiful though meaningless, a product of modern
invention like many another, some may think. But the story of a rug may
go back through many centuries to ancient times of opulent splendor,
when wars were waged and kingdoms created and shattered for the beauty
of a woman; when gorgeous palaces were raised and great spectacles of
art were shown to inspire the world for thousands of years.

Only a rug, but a relic of a rich and glowing past! For in those
distant days of war and pageantry, an era more classic than our own,
history and romance were woven into the rug. The patterns and designs
told great stories of wars and loves that swept nations away and
created great new empires and related vivid accounts of intrigue and
tragedy that determined history and inspired the immortal works of
poets and dramatists. The rug in the ancient times was also used for
religious symbolism, and sacred doctrines were inscribed in the woven
figures.

Of all the arts none has been as close to the lives and history of the
peoples of the earth as the art of weaving. Songs and stories of these
peoples and their national achievements have been immortalized through
their woven fabrics. Generations have learned of the great deeds of
their forefathers through the historical accounts woven into rugs. And
in the days of the early Greeks, Hebrews and Egyptians and on through
the succeeding centuries until the middle ages the rug was used as a
symbolical part of state, religious and romantic ceremonies.


What Makes Some Rugs so Valuable?

The reason many rugs are valued at so high a price in money is largely
due to the skill of the artist or designer, just as a painting becomes
valuable because the artist who painted it has succeeded in producing a
remarkable result. The question of rarity also enters largely into the
value of rugs. The great artist weavers of the past who worked for love
of their art rather than for the money they might secure by disposing
of their masterpieces, are dead, and they have had no successors.
Then, also, the rug becomes valuable by reason of the amount of time
and labor put into it. Many valuable rugs take years to produce,
because the artist must do all his work by hand practically and tie his
different colored yarns together just so, or the pattern will not come
right. These knots may occur every inch or sometimes even less than an
inch, and there will be thousands of hand knots in one rug.

[Illustration: MAKING TURKISH RUGS.]

[Illustration: THE OLDER THEY ARE THE MORE HIGHLY PRIZED

The above is a typical Chinese rug, containing symbolical emblems.

This is an antique and is of a class that sells sometimes as high as
$5,000, its rarity of design, beauty in colors, and scarcity enhances
its value.]

[Illustration: This is an American machine-made interpretation of a
Chinese rug. The ground is a rich gold coloring, the figures being in
ecru, dark blue, terra cotta and light blue. It is a beautiful rug, and
one of the finest examples of loom-tufted goods ever produced.]

[Illustration: WHERE THE BEST PERSIAN RUGS ARE MADE

This antique Persian was made in the district of Kurdistan, in Western
Persia. The general effect is handsome, although the design is crude.
The ground is of a deep rich red, and top colors of dark blue and ecru.

The most valuable Persian rugs come from Kurdistan, Khurasan, Peraghan
and Karman. The most highly prized come from Kurdistan. The pattern
does not show a uniform ground of flowers or other objects, but
looks more like a field of wild flowers in the spring, which is very
appropriate as a design for anything that is to be walked upon. It
is astonishing what wonderful artistic ability is displayed by some
of the members of these wild nomadic Persian people. The carpets and
rugs are woven on a simple frame on which the warp is stretched. The
woof, or cross threads, consist of short threads woven into the warp
with the fingers and without the use of a shuttle. Then a sort of comb
is pressed against the loose row of cross threads to tighten it. The
weaver sits with the back of the rug towards him, so that he depends
entirely on his memory to produce a perfect pattern.]

[Illustration: This rug is an American copy of a typical Kurdistan. It
is marvellous how well the effect in colors and design are reproduced
in this domestic rug.]

[Illustration: HOW WE IMITATE POPULAR DESIGNS BY MACHINERY

This Tabriz reproduction has all the characteristics of the genuine rug
in both design and color. The ground is of a soft rose with figures
olives, ivory and deep blue.]

[Illustration: This is a copy of an old piece of a rug in the
Kensington Museum, London, which is 500 to 600 years old. The design is
very interesting on account of the symbolical figures which cover the
ground.]

[Illustration: WOOL-PICKING MACHINE.]




The Making of Carpets


How Are Modern Rugs and Carpets Made?

The best way to learn of this is for us to take a brief visit to one
of the largest carpet factories, where we will assume we have already
arrived.

There is a sharp whistle, then an outlet of steam, the clang of a bell
and a locomotive rolls around the curve of the spur-track into the
factory yard. Attached to it are several freight cars that only the
day before received their cargoes at the New York docks fresh from
steamships coming from foreign lands. Inside the yard, the engine comes
to a stop alongside a warehouse. Sturdy men unlock the doors of the
cars and begin pulling out bales of the imported wool.

This is the first step in the evolution of a rug. Between the arrival
of the rough wool at the warehouse and the placing in the stock room
of the finished rug, splendidly woven after an artistic design shown
in attractive colors, many interesting processes are followed. It is
sufficient to state that few people looking at rugs of the Saxony,
or Axminster or Tapestry type realize the high degree of mechanical
science and artistic perception that have been brought to bear in the
manufacture of these rugs.

After the arrival of the wool there are many steps to be taken until
the skeins of yarn receive their coloring treatment in the dye-house
and, at the bidding of the great machine, assemble themselves in the
beautiful designs that the artists have created. Though there are
many details of work in the development of a rug, they have been so
well mastered that the employes in charge of every stage of the rug’s
evolution give to their work a nicety of attention in little time that
careful training and scientific understanding alone can supply.

The travel-stained covers of the bales are removed. The heavy bulk is
broken and the tightly-compressed bales loosened. Then the wool is fed
into the washing-machine, and after that goes into the picking-machine.
The process of cleansing the wool is an elaborate one, for it is so
full of dirt and grease that several waters and several operations are
necessary to its final appearance in a white and fleecy condition.
After the last washing the wool is lifted to a drying-room, where the
heat from steam-coils is forced through it by means of blowers.

The wool now passes to the sorting-room, where the blends are carefully
made before it goes to the machine which tears the wool fibers apart,
and gets them in shape for the carding and combing processes. Next
the wool is blown into a spinning mill. The wool is now ready to be
converted into yarn. It passes through a picking-machine, which blends
the different grades of the raw material, selecting the strands as to
fiber and color. Then it is refined and purified.

[Illustration: CARDING MACHINE]

Through tubes the wool is forced to the carding-room by means of air
pressure. In passing through the cards it is carefully weighed to
secure evenness in the yarn. Leaving the carding machine, the wool
is taken to the floor above, where the big spools of yarn reach the
combing machine for the next process. This machine separates the long
from the short fibers. The strands of wool are still thick and must go
through another process before they are ready to be made into yarn.
They are finally united and given sufficient strength to stand the
weaving process. As the visitor sees the strands of yarn first appear
on the machine they resemble rolls of smoke.

[Illustration: DYEING THE YARN]

~HOW THE YARN FOR CARPETS IS DYED~

The yarn next appears on rows of spindles in the mule-room, six hundred
feet long, where the yarn is twisted and brought to its final stage.
The yarn now is ready for the dye-house. Here the atmosphere is very
dense. Clouds of steam rise from the many vats of boiling dyes. The
yarn receives the coloring for which it is intended, or is bleached
in an adjoining department, and then is transferred on poles to the
drying-room, after passing through a steaming process which sets the
color. Next it passes on an electric conveyor to the weave-shop.

Considerable skill is required in the weaving process. The assembling
of the yarns and matching of colors require expert attention. The
skeins of yarn are wound on spools, which are put in sets back of the
looms, each color or set representing one “frame” of color in the rug.
By the famous Jacquard motion of cards each color wanted in the surface
of the rug is pulled up in its proper place, the other frame color
laying in the back of the rug. The mechanical process is a remarkable
sight. As the pattern forms itself from the mechanical devices, the
onlooker is struck with the wonder of it.

[Illustration: HOW A CARPET IS WOVEN BY MACHINERY

WEAVING A RUG BY MACHINERY]

[Illustration: 10,000,000 YARDS OF CARPET PER YEAR FROM ONE FACTORY

This picture shows the plant of one of the largest carpet factories in
the United States at Thompsonville, Conn. From the looms of these mills
are annually produced ten-million yards of the twenty-five different
grades of carpet manufactured by this concern.

Imagine a strip of carpet across the United States at its widest
part, the Forty-second latitude--a strip of “Hartford Saxony”, say,
stretching from the Atlantic seaboard to the Pacific coast; and then
another carpet strip the length of the United States, where this
country is the longest--i. e., from the Northern boundary of the
state of Minnesota to the Southern boundary of the state of Texas;
then imagine one more strip stretching from Chicago to New Orleans,
and finally a connection between the two latter strips at about the
vicinity of St. Louis.

With a mental picture of this vast country thus stripped with carpet,
you wonder if there is that much carpet in the world. It seems
incredible that this great sweep of land could be measured with
carpet--and yet enough material comes every year from the looms of one
carpet factory alone in this country to strip the United States East
and West, and North and South as indicated above.]

The weave is now completed; the rug comes out. But it is rough and
has to be finished. It is passed through a machine that removes the
roughness of the face as a lawn-mower cuts away the top-grass. The ends
are finished, and the carpet is complete.

~SOME DESIGNS STAMPED ON YARN BEFORE WEAVING~

The pattern of tapestry carpet is obtained by printing the colors
to appear in the design on the yarn which forms the face before the
weaving is started, by means of large drums. After all rugs leave the
weave-shop a force of skilled women examine them carefully to make sure
that there are no defects. Every yard of the annual output of carpet
and rugs is inspected five times before it leaves the factory.

[Illustration: EXAMINING AND REPAIRING]

[Illustration: PACKING FOR SHIPMENT]




Why Do I Yawn?


When you yawn, you do so because you have not been breathing quite
properly and for some reason or other your blood supply has not been
getting sufficient oxygen through the air which has been taken into
your lungs. Nature’s way, in this instance, is to call for a big intake
of air all at one time, and since it is important at such times that a
large quantity of air should be supplied to the lungs at once, nature
has so arranged matters that certain muscles shall cause you to open
your mouth wide and take in as much air as you can at one time, and
also has arranged so that it is almost impossible to keep from yawning
when the demand for it is once made. The yawn is controlled by a part
of our nerve structure which looks after the breathing apparatus.

The satisfaction we feel after a wholesome yawn is due to the fact that
having replied to nature’s demand that we bring in more air, our blood
secures the oxygen which it needs and we feel the effect of better
blood in our arteries at once.

A peculiar thing about the process of yawning is that one person in
a room yawning will quite likely set all or nearly all the others to
yawning also. There seems to be no explanation of this excepting that
when a number of people are in one room and one of them begins to
yawn, the others do so, not because they perceive the first yawn so
much as the probable fact that the air in the room has become so poor
that there is not enough good air for all the people in it, breathing
normally, and many of them are forced to yawn at about the same time.




Where Do Living Things Come From?


This is a big subject, but a very interesting one. To understand it
fully we must begin at the very beginning of the world.

God made first of all the rocks, the mountains, the sun, the moon, the
stars, the soil, and put the water in the lakes, rivers and oceans.
This took a long time, but they had to be there before the living
things could begin to be.




What is Inorganic Matter?


This thing we have spoken of is called inorganic matter, which means
“without life,” and everything in the world which has no life is called
inorganic matter. These things do not die, and for that reason do not
have to be replaced. The form and appearance of inorganic matter and
its location is often changed by man or other causes, but even when man
burns the coal which he has dug up out of the ground in the furnace, no
part of it is destroyed. Some of it is turned into smoke and gas and
some of it is turned into ashes, while every other particle which went
to make up the coal originally is still in existence. It remains as
inorganic matter in some form or other.




Where Did Life Begin on Earth?


After the inorganic things had been made and the earth was ready for
life, the different kinds of living things which we find on the earth
began to exist. These are called organic objects, which means objects
“with life.” The first living things to appear were the bushes, the
grass, the garden vegetables, the flowers, trees, and all the kinds of
life which we ordinarily think of as growing things.

This division of living things makes up what we call the vegetable
kingdom, and in a general way of classing it is the kind of life
which cannot move about from place to place and which has not a sense
of feeling, or any of the other senses, seeing, hearing, tasting or
smelling.

After this division of life had been established the world was ready
for the other and more important form of life--the fishes, the birds,
cats, dogs, horses, cows, with others that we call domestic animals,
and also the lions, tigers, elephants and others which constitute the
division of wild animals.

This kind of life was given some or all of the five senses, but not
all classes of animal life possess all these senses. Some of the lower
forms of animal life, like the oysters, clams, in the fish family,
cannot see, hear, smell or taste. They can only feel; others are able
to do more of these things, and many have all of the five senses.




When Did Man Begin to Live?


Man was not created until all the other living things on earth had been
started, and he was given additional powers so that he might become the
ruler of all the other living things, principally because he was given
a brain with power to think, reason and originate.




Why Must Life Be Reproduced?


Life must be reproduced because living things die. They have power to
live only for a certain length of time. The other life in the world is
used to provide food for man, and if there were no way of reproducing
life it would not be long before man had eaten all the vegetables and
the animals too, and would himself then starve to death.

To avoid such a calamity God put into each living thing, both
vegetables and animals, a power to cause other things of the same kind
as itself to grow. This is called the power of reproduction. With this
power each kind of living thing can bring other specimens of the same
kind into the world and each kind of living thing can do this without
aid from any other kind of life.

The trees, the flowers, and other kinds of vegetable life would
reproduce themselves without the aid of man, as would also the fishes
and other kinds of animal life. Man, however, just to have things
conveniently at hand, uses his power over other life to cause his
vegetables to grow near where he lives, and keep the animals which he
wishes to use as food in some place where he doesn’t have to hunt for
them every time he wishes meat for his table. This, however, he does
only with the animals which he has domesticated or tamed. When he wants
meat from the animals which are still wild he must hunt for them as he
used to do.

Each kind of life has the power, however, to reproduce only its own
kind. If you plant a peach stone you will sooner or later have a peach
tree which will bear peaches, and these peaches from the young tree
will look and taste just like the peach whose pit or stone you planted.
There may be other kinds of fruit trees all about, and also trees which
do not bear fruit. All of the trees secure the food upon which they
live and grow from the same soil. Even the grass under your peach tree
eats the same things as your peach tree, but it remains always true
that things in the vegetable kingdom will grow only to be like the
thing from which it came.




Have Plants Fathers and Mothers?


The little trees grow up to be exactly like their fathers and mothers
(for they have fathers and mothers), which is something all living
things must have. These are not the same kind of fathers, or mothers
either, that a boy or girl has, exactly, but they are parents just the
same. So far as the trees, flowers and plants are concerned we call the
parents father and mother natures, which is a term used merely to keep
you from confusing vegetable life fathers and mothers with the regular
kind.

In the vegetable kingdom you cannot always see these father and mother
natures, which enable them to reproduce their kind of life, but
everything in the vegetable and also in the animal kingdom has them.




How Do Plants Reproduce Life?


In the spring we put seeds into the ground and later on plants grow up
where the seeds were planted, and later the flowers come. The seeds
contain the baby plants, which come to life, and after bursting the
covering of the seed, unfold and grow up into plants if placed in the
ground, where they can obtain the proper amount of warmth and moisture
to give them a start.




Why Do Plants Have Seeds?


To get at this subject in the best manner we must study first how
plants produce seeds and what happens. The power in a plant to make
another plant like it grow comes from the flower. Ordinarily we think
of the flowers as beautiful to look at and delightful to smell, but
the flowers do not grow for the mere purpose of being beautiful, but
are for a more useful purpose--to develop a seed which, when planted,
will produce another plant. The machinery for producing a perfect
seed is in the flower or blossom. Every flower has a definite plan of
construction. The leaves and colors vary, but the plan for a perfect
flower is always there. The petals which are generally colored are
called the _crown_. When you pluck off the petals you see a number
of green leaves at the bottom where the petals were attached. These
form what is called the _calyx_, and help to hold the petals in place.
Inside the flower are little stems which grow to the petals. These are
called _stamens_. Every one of these little stems is hollow, and if
you split one open you will discover a _fine powder_. This powder is
called _pollen_, and is the “father” nature of the plant. In the calyx,
the part we had left after we plucked off the petals, is the “mother”
nature of the plant. The main part of the mother nature is the stem of
the flower called the _ovary_, and this is where the seeds grow. These
seeds in the ovary, however, will not become perfect seeds unless some
of the pollen from the “father” nature of the plant touches them and
fertilizes them.

At the proper age of the flower some of this pollen powder passes into
the ovary and fertilizes the seeds and makes them good seeds. This is
only one kind of flower, however. In this kind the father and mother
natures are in the same flower. In other kinds of plants the father and
mother natures are found on different parts of the same plant.




Why Does an Ear of Corn Have Silk?


The corn plant is one of this kind. You know what it looks like--a tall
plant, generally six or seven feet high. The ears of corn grow out of
the side of the corn stalk. The ear is covered with husks and out of
the end of the ear hangs a bunch of brown silk threads which we term
corn silk. Up at the top of the plant you will see the tassel, but
you may not have known that this is the flower of the corn plant. The
tassel or flower in this case contains the “father nature” of the corn
plant, and the ear of corn contains the “mother nature.” The husks on
the outside of the ear of corn protect the grains of corn on the ear
inside and keep them tender. The ear of corn is really the ovary of
the corn plant, because that is where the seeds grow. You will guess,
of course, that the grains of corn on the ear are but seeds of the
plant. Were you to examine one of these ears of corn on the plant when
it had just started to form you would find no kernels on the cob, but
only little marks which indicated where the grains of corn are expected
to grow, but if you want to know, then, how many grains of corn were
expected to grow on the ear, you could easily tell by counting the
little silk threads which you see on the cob and which stick out over
the end. There will be a thread of silk for each grain of corn that is
expected to grow.

Every grain of corn must receive some of the pollen powder from the
tassel or father nature at the top of the corn plant or it will not
develop into a nice large, juicy kernel.




How Does the Pollen Touch the Grain of Corn?


Before the kernels of corn grow the tassel is in bloom. The wind blows
and shakes the pollen powder off of the tassel and the powder falls
on the ends of the silk which stick out of the little ear of corn to
be. Each thread of silk then carries a little of the powder down to
the spot on the ear where it is attached and thus the grain of corn
receives the fertilizing necessary to develop it into a ripe seed.
If you leave the ear of corn alone the kernel will eventually become
yellow and hard and can then be planted and will produce other corn
plants. Man, however, finds the ear of corn a delightful food, if taken
at a time when the seeds are fully grown but not yet ripened into
perfect seeds. At this stage the grains of corn would not grow up again
if planted, because they have not yet become perfect seeds.




Do Father and Mother Plants Always Live Together?


We come now to the kinds of plants on which the “father” and “mother”
natures are on different plants of the same kind. At times they will
grow side by side, at other times they will be in the same field, but
very often they grow at quite a distance from each other. In some
instances the nearest father tree will be even miles away from the
mother tree of the same kind. But in any event the pollen from the
father nature must reach the mother nature of the plant or tree before
a perfect seed can be produced. In cases of this kind the father nature
will be on one tree or plant and the ovary or mother nature on another.
The wind helps out nature in some of these cases by blowing the pollen
of the father plant to the ovary of the mother plant. In many other
instances the bees and insects help.




Why Do Flowers Have Smells?


Where the bees do this it is because the bee has been visiting the
flowers in his search for honey. They do not fly from flower to flower
for the purpose of uniting the mother and father natures of plants, but
they help the flowers incidentally while getting the honey for which
they are searching. In gathering his honey the busy bee will go all
over the father flower and get his legs all covered with pollen powder.
Sooner or later he comes to a mother flower of the same kind of plant
or tree from which he has father pollen on his legs, and, still bent on
gathering honey, he incidentally rubs the pollen powder on to the ovary
of the mother flower and the fertilization takes place. The wonderful
thing about this is that the father pollen of one kind of a plant will
not fertilize the mother nature of another kind of plant. To illustrate
this, if a bee carrying pollen on his legs from a walnut blossom visits
the mother blossom of a hickory tree the pollen of the walnut would not
affect the hickory blossom, but would still have the proper effect on
the first walnut mother blossom he visited.

This is how life in general is reproduced among the plants and trees.
Life in the vegetable kingdom has no sense of feeling or any of the
other senses, but this kind of life is still true to its own nature
and is a wise thing in the plan of creation, because, since all seed
will produce only plants like those from which the seed came, man can
control the growth of the vegetables and fruits he needs as food. He
knows when he plants corn that he will get corn in return, because
perfect seed never makes a mistake. It would mix things up terribly for
man if this were not so, because man might then plant one thing and
find another thing growing. It would be a sad thing to plant wheat and
find thistles growing.

In order that seeds may grow they must be planted under conditions that
suit the kind of vegetable life in the seed. Man has to study and learn
what these conditions are.

If a seed is planted too deeply the sun may not have a chance to warm
the ground to that depth, and if it is planted too near the surface it
may become too warm and be killed by the sun. When planted under the
proper conditions the seed soon begins to grow. It grows upward toward
the sun to get light and air, and it sends roots down into the ground
to get food and moisture.

The life in the vegetable kingdom is soon able to take care of itself.




How Are Fishes Born?


The next step in the study of the reproduction of life brings us to
the animal kingdom. The first thing we discover in this section is
that in the animal kingdom father and mother natures are almost always
separated. In plants and trees these parent natures are sometimes in
the same flower, often separated, but on the same plant, and in other
instances on different plants miles apart. What we must remember, then,
is that in the case of plants it is given more or less to the chance of
wind or other circumstances to bring the parent natures together.

In the animal kingdom there are a few cases where the mother and father
natures are found in the same living object, as in the oyster and
clam families, one of the lowest forms of animal life. These have but
one of the five senses--that of feeling. This class of animals--the
cold-blooded animals--includes the fishes, and in most members of this
class the father and mother natures are separated and in different
bodies. Step by step from now on we enter higher forms of animal life,
and through each step we find a greater difference between the father
and mother natures, and in the animal kingdom we speak of the father
and mother natures as “_male_ and _female_.” In the animal kingdom,
too, what we have previously called the seed is known as the _egg_.
Seeds and eggs are the same so far as their usefulness is concerned,
but we say eggs in the animal kingdom to distinguish from seeds in the
vegetable kingdom.

Fish have eggs, then, and it is from the eggs that little fish are born
into the world and grow to be of eatable size. You recognize the eggs
of the fish in the “roe,” which is eaten as food. Not all fish eggs are
used as food, however.

In the fish world the eggs are developed in the body of the female
fish. Each little round speck in a “shad roe” is one egg, and there
are many thousands in a single “roe.” Each egg will produce a little
fish, under favorable conditions. These eggs develop in the body of
the female fish in winter. In the spring, which is the time in which
most living things are born, and, therefore, the time for hatching out
fish eggs, all of the fish swim from the deep water where they live in
winter to the places where the water is shallow and warm, and in these
shallow waters the female fish expels the eggs from her body where the
sun can get at them and hatch them by warming them. After the female
fish has thus laid the eggs, the male fish swims over the eggs as they
lay in the water, and expels from his body over them a fluid which is
white in appearance and which fertilizes the fish eggs. If any of this
fluid fails to reach some of the eggs it is not possible for the sun to
bring them to life.

When the eggs are laid and fertilized the mother and father fishes swim
away and they never see their children or recognize them as such, even
if they meet them later in life. The parent fish do not act like other
fathers and mothers, and they do not need to, because as soon as a baby
fish is born he is able to find his own food and needs no help from
father or mother to teach him how to find it or enable him to grow into
a real fish.

Of course, many of the tiny fish are eaten by other fish and not all
the eggs which the mother fishes lay hatch into live fish, because, if
they did, the waters would be so crowded with fish that there would not
be any room for the water. A single female fish will lay millions of
eggs in a year, and if each egg developed into a fish there would be
far too many.

This order of animals, which includes turtles, frogs, etc., is the
cold-blooded class of animal life. They have only part of the five
senses. They all can feel and some of the fishes can see and hear, but
a great many of them, particularly those kinds which live on the bottom
of the ocean, cannot either see or hear, and some members of the fish
family cannot even swim.

The thing to remember about fishes in connection with the reproduction
of life is that the mother fish must select a place which is favorable
to deposit the eggs, but after that her responsibility ceases. The
father merely fertilizes the eggs, and then his responsibility ceases.
The little fish look out for themselves as soon as they are born and
never know what it is to have a father or mother to look after them.

When we study the next higher form of animal life we find that the
young ones have to be looked after, and that this becomes more
necessary as we ascend the scale of animal life until we reach man, the
most intelligent of all animals and yet the most helpless of all at
birth.




How Birds Are Taught to Fly.


The next step brings us to the birds. Before they can look after
themselves the little birds must learn how to search for food and the
kinds of food good for them. They have to learn the habits of their
kind of life. The higher you go in the study of animal life the greater
seem to be the dangers which surround the young animals and the longer
it takes to teach them how to look after themselves and what to do for
themselves.

The bird family includes not only the robins, larks, sparrows and
pigeons, but also the ducks, geese, and chickens, etc. We are all more
or less familiar with birds’ eggs, and if not we know what a hen’s egg
looks like. The eggs of the bird family are laid in nests, which is the
first sign of home building in the animal kingdom.

The birds are the first of the large class of warm-blooded animals.
The egg here represents again the reproductive power. The eggs, too,
form in the body of the female bird, but are laid in a nest which the
parent birds build together. Now this is the first step away from the
fish family. The fish looks for a suitable place to lay the eggs and
then goes off and leaves them. The birds, however, have to make a
nest in which to deposit the eggs. The fish, as you remember, depended
upon the warm sun shining on the shallow water to hatch out the eggs,
thus depending on an outside force to supply the necessary warmth. In
the bird family the mother bird must cover the eggs with her own body
and keep them warm until they hatch out. Then, too, the father and
mother birds feed the young until they are strong enough to fly and
find food for themselves, and so the mother and father birds look after
their babies until they are old enough to look after themselves. When
this time arrives the old birds cease to bother about the young ones
altogether. The fishes never act like parents after the baby fishes
are born, because the little fish are able to look after themselves
right away. The parent birds are a good deal like fathers and mothers
for a time, but only so long as it takes them to teach their little
bird children to look out for themselves. Then they forget the children
completely.

It requires but a few days and no parental care to hatch out a family
of baby fishes and no attention at all after birth. It requires several
weeks and much patience for the parent birds to hatch out their eggs,
and it involves care and attention for several weeks to teach baby
birds to take care of themselves.

This being a father or mother in the animal kingdom becomes a greater
responsibility in every step as we get closer to man, and when we reach
man we find him to be the most helpless offspring of all at birth, and
that it takes more time, care and attention to bring up a human child
to maturity than any other animal.




What Makes the Hollow Place at One End of a Boiled Egg?


This hollow place on the end of the boiled egg (sometimes it shows on
the side) is the air which is put inside of the egg when it is formed
so that the little chicken will have air to breathe from the time it
comes to life within the egg until it becomes strong enough to break
the shell and go out into the world. There is also food in the egg for
him. When you boil the egg this pocket of air within the shell, which
would have been used up by the chick if the egg had been set to hatch
instead of being cooked for breakfast, begins to fight for its space
and pushes the boiling egg back and forms the hollow place.

The purpose of the air in the egg is a good thing to remember when we
come to study the higher forms of animal life from the standpoint of
how they reproduce themselves.

The mammals are the next higher form of animals. The babies of this
class of animals must be fed for several weeks or months before they
are ready to come into the world.

A little chicken is ready to come out of the egg almost as soon as it
comes to life, and, therefore, needs only a little air and food before
it is strong enough to peck its way out, but the babies of mammals
begin to live months before they are ready to come into the world, and
they need a great deal of air and food during this time. This class
includes the dogs, horses, cows, cats and all other animals in the
Zoo and in the woods. The name mammals means the same as “mamma,” and
indicates an animal which must be fed from the body of a female mammal
even after it is born.

In this class the eggs are retained within the body of the female
animal instead of being laid in a nest or some other place, as in
animals of lower classes, after being fertilized by the male animal,
so that the baby animal may secure its food and air from within the
mother’s body after the life within the egg is begun.

The mother’s body supplies the necessary warmth to develop the life
of the little animal in the egg, just as the birds supplied this with
their bodies. In the bird class it only takes a few hours to give
the little bird sufficient strength to peek his way out, but in the
mammal class it is a long time before the baby animal is strong enough
to come out into the world, and even after it is born the babies of
mammals require a great deal of care and attention before they are able
to look out for themselves. During this period the animal secures all
of its food from the breast of the mother animal.

Another reason why the eggs of mammals are retained within the bodies
of the females is the need for protecting the young animals from
enemies. In the animal kingdom each kind of animal preys upon another
kind. They attack and devour each other and are constantly in danger.
If, then, mammals laid eggs in nests and sat upon them to hatch them
out, the mother animals sitting on the nests would be continually in
danger of attack from their enemies. They would either have to flee
and subject the nest and its contents to the danger of destruction or
else stay and fight, and perhaps be destroyed. But by carrying her egg
within her body the mother mammal is able to move about from place to
place and protect her baby.




Is Man an Animal?


Men, women and children belong to the “mammal” class of animals. The
offspring of the human family is the most helpless of all animals at
birth. The young of most kinds of mammals can stand on their legs
shortly after being born, but the human baby requires months before it
can stand up. A baby horse can also walk within a few hours, but human
children do not begin to walk until they are more than a year old.




Why Cannot Babies Walk as Soon as Born?


The human baby has a great many more things to learn than a horse baby
before it is safe for him to go about alone. It takes time for the
brain to develop, and if a baby could walk before the brain had even
partially developed it would only get into trouble.

This, then, is what we have learned about the reproduction of life
and the reasons for its being different in different classes of life.
First, we had the division of organic life into the vegetable and
animal kingdoms. Life in the vegetable kingdom has none of the five
senses, for plants cannot see, hear, feel, smell or taste. They cannot
move from place to place, but remain where they grow until destroyed
or removed. On the other hand, all animal life has at least one of
the five senses--feeling. The oysters and clams belong to this class.
Starting with this level of life in the animal kingdom we find that as
we go on up through the different classes we find each class able to
do things which make it superior to the class below it, until we reach
the human mammal, who can do most of all. And, further, that since each
class as we go up in the scale of life has greater ability to do things
than the class beneath it, so in each case the task of the parents
in preparing their offspring for their kind of life becomes greater,
and the period during which the offspring is learning becomes longer
and longer until we reach the human family, in which we find that
parents have the greatest responsibility, and the children are the most
helpless of all animals, but that in the final result man has a right,
on account of his superior qualities, to be the ruler of the other
creatures of the world.




What Are Ball Bearings?


Some years ago a gentleman in trying to find some way to reduce the
friction, which is constantly developed to a certain extent, even when
the axle is oiled, discovered that if between the axle and the inside
of the hub a circle of steel balls were arranged, so that the hub of
the wheel did not touch the axle at all, but rested on the little balls
which in their turn touched the axle, that a great deal of the friction
was eliminated. This proved to be a wonderful invention, and when this
combination is arranged and oiled, there is hardly any friction.




Why a Gasoline Engine Goes


[Illustration: FIG. 1.]

As you know, gasoline is a very inflammable fluid, and will explode if
placed too close to fire.

This explosive quality is the basic principle of the gasoline engine.
By admitting a small quantity of gasoline vapor into an enclosed
cylinder, and exploding it by means of an electric spark, repeating
this operation continuously, the engine is given a regular rotary
motion.

Look at Fig. 1. Starting from the gasoline tank, the fluid is fed
into the ‘carburetor’, which is a sort of atomizer. Here the gasoline
is mixed with air, and broken up into a very fine spray, in which
condition it will explode readily.

The engine will not start of itself. Its fly-wheel must first be turned
by hand, or by some other outside force, until the first explosion
takes place. After this its action is automatic.

As shown in Fig. 1, the fly-wheel is being turned, and is drawing the
piston down the cylinder, which in turn sucks gasoline vapor, (shown by
little arrows) through the ‘intake valve’. This ‘intake valve’, and the
‘exhaust valve’ on the opposite side of the cylinder, are opened and
closed at the proper time through the action of the gears shown in the
illustration.

Passing to Fig. 2, the fly-wheel in turning has drawn the piston to
its lowest point, and is now shown forcing it up the cylinder. This
compresses the gasoline vapor in the cylinder to a density at which its
explosion produces the greatest amount of power. The intake and exhaust
valves are both closed.

~WHAT CAUSES THE EXPLOSION IN A GAS ENGINE~

Fig. 3 shows the explosion. The cylinder has been filled with
compressed gas, and the piston has again started on its downward
travel. The spark plug, set in the top of the cylinder, makes a spark
every time an electrical current passes through it. A switch on the
engine permits the current to pass to the spark plug only when the
engine is at this position in its action. (Fig. 3.) The consequent
explosion drives the piston downward with great force, turning the
fly-wheel, which by its weight continues the rotary motion after the
downward impulse of the piston has been expended.

Fig. 4 shows the fly-wheel, still turning, forcing the piston up and
thus expelling the burned gases from the cylinder through the exhaust
valve, held open for this purpose. From this position the engine
goes again to that of Fig. 1, and through 2, 3, and 4, continuously,
exploding every second revolution, and giving a regular rotary motion
to the fly-wheel.

[Illustration: FIG. 2.]

[Illustration: FIG. 3.]

[Illustration: FIG. 4.]

The illustrations show a one-cylinder motor, but these engines can be
built with two or more cylinders, arranged to explode at different
times, thus giving very smooth action to the fly-wheel and main shaft.

Aeroplanes, almost all automobiles, various pumps and other machinery
are driven by gasoline engines. The rotary motion can readily be
transmitted by chains or gears to the propellor of an aeroplane or
motor boat, or the wheels of an automobile. It is only in the past few
years that the gasoline engine has reached its present high state of
perfection.

[Illustration: THE BEGINNING OF AN AUTOMOBILE

CRANKCASE SHOWING BEARINGS.

The heart of the automobile is the engine. It is built around the
crankcase, which is its foundation or base.]

[Illustration: CRANKCASE WITH CRANKSHAFT AND FLY-WHEEL ADDED.

The crankshaft serves the same purpose in an automobile as the pedals
do on a bicycle.

The fly-wheel on the end helps it to keep turning at an even speed.]

[Illustration: Gasoline vapor is exploded in the cylinders. This pushes
the piston down, and as the piston is connected to the crankshaft it
starts the crankshaft turning.

The piston and the rod that connect it to the crankshaft are just like
the feet and limbs of any one riding a bicycle.

Cylinders showing piston in place and connected to crankshaft.]

[Illustration: The gears or “cog-wheels” are for running the fan, the
pump and other parts.]

[Illustration: THE HEART OF THE AUTOMOBILE

Cylinder added to crankcase.

The cylinders are next bolted down to the crankcase, the pistons and
crankshaft having been connected, as shown in Fig. 3. A cover is placed
over the gears to keep them clean.]

[Illustration: An oil pan or reservoir is attached to the bottom of the
crankcase to hold oil for the engine.]

[Illustration: The carburetor furnishes the gasoline vapor for the
cylinders. It is connected to the engine by a crooked pipe called the
intake manifold.

After the gasoline has been exploded a valve opens and allows the
burned gases to escape through another pipe, called the exhaust
manifold.]

[Illustration: Oil is poured in the spout which is at the left of the
carburetor. It runs down into the reservoir and is pumped up through
the engine a little at a time.

Oil pump and filler added to motor.]

[Illustration: THE POWER PLANT OF AN AUTOMOBILE

The electric generator makes electricity to be used for starting the
engine and lighting the car.]

[Illustration: The magneto gives an electric spark, which explodes the
gasoline in the cylinders.

The water pump keeps water flowing around the cylinders to prevent them
from getting too hot. This water comes back to the pump through the
radiator at the front of the car. Wind blows through the radiator and
cools off the water. The tire pump on up-to-date cars is run by the
engine. It does not pump except when the gears, which are shown in the
picture, are pulled together.]

[Illustration: An electric motor starts the engine by turning the
fly-wheel. This makes it unnecessary to get out and crank the car by
hand.]

[Illustration: SECOND STAGE OF CONSTRUCTION

The transmission is added.

The transmission makes it possible to reverse the car. It also enables
the driver to go into high-speed gear when on level roads and low-speed
gear for starting and for pulling hills.]

[Illustration: Double-drop pressed steel frame.

The frame on which the car is built.]

[Illustration: Addition of semi-elliptic and three-fourths-elliptic
springs to frame.

Large springs are placed at the front and rear of the frame. They make
the car ride smoothly.]

[Illustration: Adding the front axle.]

[Illustration: READY FOR THE WHEELS

Showing addition of full-floating rear axle.]

[Illustration: Completed engine and transmission is next fastened to
the frame and connected to the rear axle by the drive shaft.]

[Illustration: Showing addition of gasoline tank and gas lead to
carburetor.]

[Illustration: Showing how steering gear is connected.]

[Illustration: WHAT THE COMPLETED CHASSIS LOOKS LIKE

Wheels are next added to chassis.]

[Illustration: Completed chassis with radiator added.

The water which keeps the engine from getting too hot is pumped around
the cylinders and then through the radiator. The wind blows through
the little openings in the radiator, and cools off the water. Then the
water is pumped around the cylinders again.]

[Illustration: The steps and fenders are next attached.]

[Illustration: THE MARVELLOUS GROWTH OF TWENTY YEARS

The finished car.]

[Illustration: GASOLINE AUTOMOBILE.

The first American-built automobile, now in Smithsonian Institute,
Washington, D. C., where this photograph was taken. The rude carriage
that was a curiosity twenty years ago and less--the vehicle that vied
with the two-headed calf and the wild man of Borneo at the county
fairs--was the beginning of the greatest transportation aid since the
birth of civilization. Because of it our standards of living have
become higher. It has broadened the horizon of all of us.

Built by Elwood Haynes, in Kokomo, Indiana, 1893-1894. Equipped with
one-horse-power engine. Successful trial trip made at speed of six
or seven miles an hour, July 4, 1894. Gift of Elwood Haynes, 1910.
262,135.]

[Illustration: When an automobile passed you twenty years ago.]

[Illustration: HOW AUTOMOBILES HAVE IMPROVED

LEFT SIDE VIEW

RIGHT SIDE VIEW

A new exhibit in the Smithsonian Institute, officially known as
“Exhibit Number 56,860,” is attracting a great deal of attention from
visitors to the National Museum. It consists of a complete Haynes
six-cylinder unit power plant, and has been given a position at the
side of the original Haynes “horseless carriage,” where the striking
contrast shows the remarkable improvement that has been made in motor
design and construction during the past twenty-two years.

The most important features of the power plant are shown clearly and
comprehensively by having sections cut away from the various parts, so
that the visitors to the Institute are enabled to see the mechanical
construction, and the relation of the component devices.

On the right side of the engine, the intake and exhaust manifolds
are shown in their natural position. A full vertical section of the
Stromberg carburetor gives a good idea of how the gasoline is mixed
with the air and supplied to the cylinders. The Leece-Neville generator
has its casing cut away to give a view of the windings and cores.
Numerous windows have been cut into the crankcase to disclose the
crankshaft construction and the oil reservoir. The transmission gears
are also shown in this manner.

Most of the electrical equipment is shown clearly on the left side of
the motor. Here an interesting feature is the full vertical section
of the American Simms high-tension dual magneto. A half section has
been removed from the rear cylinder, and the piston as well, to
give a glimpse of the interior construction. A large portion of the
Leece-Neville starting motor casing has been cut away. The cover-plate
on the switch controlling the starting motor has been replaced with a
glass cover to display the method of completing the circuit from the
battery to the motor. A skeleton selector switch is mounted at the rear
of the transmission case, instead of its usual position on the steering
wheel. The electric gear-shifting mechanism is made visible by using a
glass plate for the top cover-plate on the transmission.]




Why Does the Heart Beat When the Brain Is Asleep?


Under ordinary conditions the heart beats are controlled by certain
nerve cells which are located within the heart itself, and these cause
the heart to beat even while the brain is asleep. This explains why
the heart beats when the brain is asleep, and the fact that the brain
when asleep does not exercise its functions, shows how necessary this
arrangement and the control of ordinary heart beats is. If this were
not so, we should not be able to live while asleep. It is just like
the management of a great business in this sense. The general manager
of a great business has control of the entire works, but there are
occasions when he must be thinking of only one thing in connection with
the business, and so he must have his organization so complete, that
the parts which he cannot be thinking about at the time will do their
work just the same. So he surrounds himself with competent assistants,
who look after certain departments while he is busy or away or asleep,
and if anything goes wrong while he is away, he calls on special forces
to set things right. Now, the brain is the general manager of the whole
body and has these nerve cells in the heart as a sort of assistant
manager to look after the heart beats in ordinary conditions, and to
keep the heart going while he is asleep. But, by reason of his office
as general manager, the brain has a special way of sending orders to
the heart through special nerves which run from the brain down each
side of the neck to the heart. There are two pairs of these special
nerves. One pair, if set in motion, will make the heart beat faster,
and the other pair will make the heart beat more slowly.




Why Do Our Hearts Beat Faster When We Are Running?


When you start running, the brain knows at once that your legs and
other parts of the body will need more blood to keep them going, and
so the brain sends down orders through his special nerves which make
the heart beat faster, to get busy, and they do. Then when you stop
running, your heart is beating faster than necessary--there is really
an oversupply of blood being pumped through your system for the time
being, and that makes you uncomfortable, until the brain sends word
through the other set of nerves to the heart to slow down the heart
beat. It is better to stop running gradually, to give the heart a
chance to get back to its normal beat gradually also.




Why Do I Get Out of Breath When Running?


This is also caused by your brain in its efforts to keep up your supply
of good blood. We breathe to take air into the lungs, where the blood
which has once been through the arteries and comes back on its return
trip to the heart, is exposed to the air in the lungs, before going
back into the heart. The air which we take into our lungs purifies the
once used blood and makes it into good blood again. When you run the
heart pumps blood into your arteries faster to enable you to run. Thus
also, the arteries send much more blood back to the heart through the
veins, and this must be purified by the lungs before going back into
the heart. To attend to purifying this extra amount of spoiled blood
the lungs need more air, and thus you are made to breathe in more air
for the purpose. Unless you are in good training--your wind in good
condition as we say--it is almost impossible for you to supply the
lungs with enough air for the purpose, but whether you can do it or
not, the lungs call upon you for more air, and cause you to try to get
it, and that is what makes you get out of breath.




Why Does My Heart Beat Faster When I Am Scared?


The natural tendency of a scared creature is to run or fly. The effect
of being scared has the same effect on the brain that your starting
to run has. The brain is always as quick as you are, and knowing that
when you are scared your actual or natural inclination is to run, it is
merely getting you in shape so that you can move or run fast.




Why Does Cold Make Our Hands Blue?


Your hands appear blue when cold because the veins which are near the
surface are filled with impure blood which is purplish in color. Your
hands become cold because there is not sufficient circulation of warm
red blood going on to keep them warm. The blood in circulating through
your body sends warm red blood through the arteries, and this is
returned to the heart through the lungs by way of the veins. The veins
carry only used-up blood or what is left of the good red blood when the
arteries are through with it. Its color is a purplish blue.

When your hands are blue it means that circulation of good red blood
has practically stopped--the red blood is not flowing from the heart
through the arteries in sufficient quantity and there is no color in
the arteries, as the blood from the arteries has practically all gone
into the veins. The veins are full to purplish blue blood, and this
makes the hands look blue, because there are a great many veins in the
hands close to the surface.




Why Do I Get Red in the Face?


Now, when you rub your cold blue hands together, you start the
circulation going again, and that brings the red blood into the
arteries, giving you the healthy red color again. When you run hard to
get red in the face because you are causing an unusual amount of red
blood to flow through your whole body by your violent exercise. Some
people with an extraordinary amount of circulation are red in the face
all the time. This is because of the presence of a great deal of blood
in the arteries, or because the walls of their arteries are so much
thinner than others that the red blood shows through more easily.




Is Yawning Infectious?


Yawning is infectious to the extent that other habits are. The desire
to yawn which comes to us when we see some one else does so comes under
the heading of suggestion. The power of suggestion is greater than many
of us realize. We are great imitators of each other. When one of us is
downhearted, we are apt to become happy and glad simply by being with
other people who are happy and glad. If enough people one at a time
tell a perfectly well man that he looks sick, he will actually feel
ill, provided he does not suspect a game is being played on him. So a
good actor carries his audience with him. He can make them laugh or cry
almost at will, and if he yawns, his audience will begin yawning.

Often, however, there is no acting connected with the yawning of the
first person. Then the yawn is caused because the person is not sending
enough good air into the lungs for purifying the blood, and the yawn is
only nature’s way of making us take an exceptionally deep breath of air
in at one time. This lack of sufficient good air in the lungs may not
be due to the poor breathing, but to the amount of bad air in the room.
In such cases it is quite likely that other people in the room yawn
when one of them starts it because they all begin to feel the need of
more good air at about the same time.




What Makes Me Want to Stretch?


The necessity or desire to stretch comes to us because certain parts of
the body are not receiving the proper amount of blood circulation and
it is these parts that we stretch at such times. If you have ever been
to a ball game, you know, of course, that it has become customary for
the crowd, no matter how large, to stretch its legs and arms during the
last half of the seventh inning. In fact, that has come to be a fixture
at ball games and is universally known as the “stretch inning.” Now,
it is not so much the result of a desire to encourage the home team as
the natural following out of nature’s laws that originally started this
practice. The end of the seventh inning at a ball game generally means
that the crowd has been sitting quite still for the greater part of an
hour and a half, just long enough for the circulation to become poor
in parts of the body, and the custom of stretching at a ball game thus
comes from the necessity of getting a little more speed into the action
of the heart to increase the blood supply.

In other words, the stretching constitutes a mild form of exercise. You
will notice the ball players themselves do not stretch themselves in
the last half of the seventh inning. They are getting enough exercise
without that.

It is natural, however, for us to stretch as we wake up from sleep
after having lain quietly in one position for one or more hours. It is
nature’s way of causing the heart to work faster.




What Happens When I Stretch?


What happens is simply this. When you stretch your arms and legs, you
squeeze the arteries and veins which are a part of your arms and legs,
much as happens when you pull on a piece of rubber tubing. The tubing
becomes flat instead of perfectly round, and it is not so easy to send
water through a flat tube as through a round one. Just so with the
heart. It is the heart’s business to send blood through the arteries
at all times, and when you make them flat the heart’s job becomes just
a little harder, and it goes to work beating just a little faster to
overcome this extra difficulty. By that time you are through stretching
and the heart is busy pumping blood a little faster than ordinarily,
and that is what makes you feel so good after you have stretched.




Why Can We Think of Only One Thing at a Time?


If you are asking the question intelligently, you must know that to
think means to concentrate, and in that sense we can only think of one
thing at a time, because it takes all of that part of the brain which
is used for thinking for just one thing. To give close attention to any
one subject means to turn the entire brain force practically in one
direction. To let other things pass through the mind at the same time
may appear not to interfere with the one thought, but they do, and our
conclusions suffer accordingly.

You can be doing something with one part of your body, while engaged
in thinking of one thing, but only such things as are more or less
mechanical as the result of habit, such as walking, or moving the
arms--things which the parts have done so often that actual attention
by the brain is not absolutely essential. Take for instance, the fact
that a man in deep thought on one subject will sometimes walk up and
down the room or along the sidewalk. He can do this walking and still
think concentratedly, but if he stubs his toe on the leg of a chair or
on a rough place in the walk, his thought is broken, because the brain
immediately takes itself out of the thought and pays its attention to
the toe that was stubbed.




Why Do I Turn White When Scared?


Simply because, when you are scared or frightened, the blood almost
leaves your face entirely. Under normal conditions, the red blood which
is flowing through the arteries of your face, gives the face a reddish
tinge, and your face becomes white when you are frightened, because
then the blood leaves the face. It is quite singular, but when you are
really frightened, whatever the cause may be, the human system receives
such a shock that the heart just about stops beating all together. When
your heart stops beating of course the flow of the blood from the heart
stops and then there is no supply of fresh red blood coming through the
arteries under the skin of your face. Therefore you look white--the
color your face would be if no blood ever flowed through your arteries
and veins. Some people have faces so white they look as though they
were scared all the time. This is not because they have no blood
flowing through the veins and arteries in their faces, but because
their supply of blood is less than other peoples, and sometimes because
the walls of their arteries and veins are much thicker than the average
that the color of the blood does not show through. There are also many
people who have so much blood in their systems all the time, and the
walls of whose arteries are so thin, that they look at all times as
though they might be blushing.




What Makes Me Blush?


Anything that will make your heart send an extra supply of blood into
the arteries and veins which supply your face with blood, will make you
blush. Embarrassment will do this. So will anger generally, although
sometimes people get so angry that the blood is driven out of their
faces. In this case they are so angry that their heart has stopped
beating, practically.




What Occurs When We Think?


When we think the mind is acting on sensations; it is receiving, in
conjunction with memories of sensations it has previously received.
Sensations as they reach the mind arouse the mind to activity and, as
soon as the sensation is received, the mind begins to compare the new
sensation with sensations received at previous times, and by putting
things together reaches a conclusion.

When you are thinking you are really trying to call upon memory to
help you. You know the thought of one thing calls up another, and this
leads to something else. This association of ideas is the faculty which
enables us to think consecutively and accurately. It is the business of
the mind to receive the sensations that enter it and arrange them in
their proper places. That memory of past sensations is the important
part of thinking, is proven by the fact that when we have forgotten a
thing we are unable to think what it was.




Can Animals Think?


For this reason if animals have memory they should be able to think. It
is now believed that many animals have to a certain extent the power to
remember.

A dog will recognize his master even though he has not seen him for
years. We might think he does this by his highly developed power of
smell, but if his master has come from a direction opposite to that
from which the dog first sees him, he could not have tracked him by his
smell. A dog will recognize his master from quite a distance, so he
must have to a certain extent the ability to remember or the power of
association of ideas, which amounts to the same thing. Again, a horse
that once belonged to the fire department, even though now hitched to a
milk wagon, will have the impulse to run to the fire when he hears the
fire gong. And an old war horse will prick up his ears as he used to
when he hears the bugle call.




Why Do I Sneeze?


You sneeze sometimes when you look up at the sun or at a bright light.
There does not seem to be any real good explanation of why looking at a
bright light should make you sneeze. It is due to the connection there
is between the nerves of the eyes and the nose. You generally blink if
you look at a bright light suddenly, and the blinking process stirs the
nerves inside of the nose to make you sneeze.

You know, of course, that the start of the sneeze is inside of your
nose. The nose is, besides being the organ of smell, the channel
through which we take air into the lungs, when we breathe properly.
The nose is lined with membranes, back of which are a net of very
small nerves which are extremely sensitive. The membranes are placed
there to catch and hold the impure particles of matter which come into
the nose when we take in a breath of air, and sneezing is only one
effective way of cleaning out the nose. It is brought on only when some
particularly difficult job of nose-cleaning has to be done. Pepper up
the nose will make you sneeze quickly, because pepper produces a very
great irritation inside the nose, and the nose goes to work at once to
get rid of it in the quickest possible manner as soon as the pepper
comes in. Other things have the same effect. Sometimes a cold in the
head causes you to sneeze. The sneeze in that event is merely nature’s
effort to clean out the nose when other efforts have failed.

There are many suggestions for stopping a sneeze before it takes place,
after you feel it coming on, such as putting the finger on each side of
the nose, and many others. But a half sneeze does not remove the cause
of the sneeze, so it is much better to sneeze it out, and many people
enjoy the after effects of sneezing so much that they take snuff into
the nose to produce it.




What Happens When I Swallow?


The muscles of your throat act in the form of a ring when food passes
into your throat. The food does not drop directly into your stomach. In
other words, the action is not quite the same as when you drop a stone
out of the window. When you do the latter, the stone hits the sidewalk
or whatever is below at the time, with a smash. It would hardly do to
have our food drop into the stomach, so the muscles of the throat are
arranged to contract in rings which push or squeeze the food downward,
and the food is passed from one ring of muscles to the other. It is
just like pushing a ball down into the foot of a stocking that is
apparently too small for it to drop down. You put the ball in the top
of the stocking and then by making a ring of your fingers around the
stocking you can push the ball down. When you swallow, you start the
muscles of your throat to making these rings. The upper ring squeezes
the food on to the ring below it and so on down to the stomach.




What Makes the Lump Come In My Throat When I Cry?


The “lump” which comes up into your throat when you cry is caused
by a sort of paralysis of the rings of muscles in your throat. The
muscles of your throat can make these rings or waves upward also, but
it is more difficult upward than downward--probably because of lack
of practice, as we say. When you have put something into your stomach
that makes you sick and causes you to vomit, the throat muscles take
the matter from your stomach and bring it back to the mouth in the same
way, except, of course, that this action begins at the bottom.

Sometimes when you cry, or lose control of yourself in some other
way (you know, of course, that in crying you always lose control of
yourself, don’t you) practically the same effect is produced as when
you have something in your stomach that should come out. Crying, or the
thing that happens sometimes when we cry, makes the throat muscles act
just as if we were vomiting, and as the action is an unnatural one,
when the ring or wave reaches the top of the throat, we feel the lump
or ball as we call it. We feel the lump because the throat has been
made to go through the motion of eliminating something in an unnatural
way, just as your arm will hurt if you pretend to have a ball or a
stone in it, and in throwing the imaginary ball or stone, you put the
same force into your movements as you would if you had an actual ball
or stone in your hand and were seeing how far you could throw it.




Why Do We Stop Growing?


We eventually stop growing because certain of the cells of the body
lose their ability of increasing in size and producing other cells. It
is one of the marvels of the construction of the human body that this
is so and one of the wisest provisions also. At first the cells of the
body crave lots of food and increase in size, divide and then the parts
go on growing until they become of a certain size, when they again
divide and each part goes on growing, etc., and thus we grow. A growing
boy needs more fond than a mature man, because he needs some of it to
grow with, while the man only has to keep what growth he has going, i.
e., alive.

We say this limit of growth is a wise provision of nature because if
there were no limit to the size we might become, we would not know how
large to build houses, barns, etc., or else we would have to build them
so large to start with that we would be lost in them for a long time.
We would constantly be forced to change these things and there would
be no basis to reckon from. Dogs might be as big as elephants and then
they would be of no use to us, or of what use would a dog as big as an
elephant be to a boy of five years. You see it would not do at all to
have this rule changed.




Why Do We Grow Aged?


We age directly in accordance with the lives we lead. You can bend
a wire back and forth a number of times at the same point without
breaking it, but eventually it will break. Just so with the human body.
You can use each part of it for its own purposes a number of times, but
eventually the break will come. Or, you can fail to make a part of it
perform its regular functions, and it will die--the break will come.
The human body is the most wonderful machine in the world, but even it
will eventually wear out. Every time you move your arm, leg or some
other part of your body, you destroy some tissues. The body replenishes
and builds up those tissues again for a certain time. When you bend a
joint in your body, the body oils the joint naturally, but as you grow
older, or rather, as you use the different parts of your body more and
more, it brings nearer always the time, when the body cannot, of its
own accord, build up again the tissues you have destroyed. That is why
some people become very old at forty and others are still comparatively
young at seventy. It requires a great deal of care and attention and
the elimination of all abuse of the body to keep us young when we
are old. The use of drink, lack of sufficient sleep and other abuses
prevent the body from restoring the tissues which have been destroyed.
Worry and sorrow age us very rapidly, because these things affect the
nerves. If the nerves are not quiet we cannot get any rest and without
rest we grow old very rapidly.




What Causes Wrinkles?


Wrinkles come to us in several ways. An easy way to cause wrinkles is
to scowl and frown and get into the habit of doing this. When you scowl
or frown you pucker up the skin on your forehead into wrinkles and if
you continue the habit the skin on your forehead makes the wrinkles
permanent. You have given your skin the wrinkle habit. This acts just
the same way as your arm would, if you tied it up in a sling and held
it close to your side for a very long time--a number of weeks. When you
took the sling off you would find your arm useless--a dead arm. It had
developed the habit of doing nothing.

In old people, however, wrinkles come more naturally. There it is the
case of the skin not receiving the proper nourishment and attention to
keep the circulation of the blood right. When people become old they
are apt to lose the fat which has accumulated under their skins. If
they had taken just the right amount of exercise all of their lives and
kept their circulation perfect in all parts of the body, there would
have been no fat there. But when the fat accumulates, it makes the
skin grow larger, and then when the fat disappears and people get thin
again, the skin is too large and makes the wrinkles.




Does Thunder Sour Milk?


Milk will sour in any kind of warm and moist temperature and, because
just before and during a thunderstorm the air is generally quite warm
and moist, it is only natural that it should turn sour. It is wrong,
however, to say or think that thunder makes milk sour. Thunder is only
a noise and noise cannot do anything but make itself heard. The fact
that it is generally warm and moist, however, when it thunders, coupled
with the fact that these conditions of the air sour milk very rapidly,
have led people to connect the two in their minds and caused them to
fall into the error of believing that the thunder is responsible for
the change in the milk.




What Makes the Rings in the Water When I Throw a Stone Into It?


Every movement has a beginning. When a movement on the earth is once
started it keeps on going until something stops it. If nothing stops it
it will go on forever.

When you shout you start air waves going in every direction, which
keeps on going until stopped by something which has the power to break
up their waves.

When you throw a stone into the ocean you start a series of ripples
or waves which spread out in every direction and if you dropped your
stone into the exact middle of the ocean--half way from each side--in
a perfectly calm sea undisturbed by other forces, your ring of ripples
would go on getting larger until it landed on the beach or shore on
each side of the ocean at the exactly the same time and there the beach
or shore would stop it.

The original ring of ripples is caused by the fact that when you drop
a stone into the water it disturbs the water where it goes in and
the water moves away from the stone to the sides, and as the stone
goes down, over and up above it, and the whole body of the water is
disturbed in such a way that makes the ripple appear on the surface and
spread out in every direction. As the stone goes down into the water
further and further the disturbance is repeated and ring after ring
appears on the surface.

Of course there are many disturbances in the water at all times. Many
things may happen to break up your little ring of ripples before they
touch the sides of the ocean--a ship--a fish--the wind--or one of many
other things, and because this is true you would have difficulty in
sending the waves made by your little pebble across the ocean, but you
can take a dishpan from the kitchen and after filling it with water
drop pebbles into it as nearly the middle as possible, and you will see
the ripples or waves your pebble makes spread out from the point where
the pebble entered the water in all directions.




Why Are There Many Languages?


Different languages developed in different parts of the world
because there was no inter-communication between people in different
communities, and each was really developing a language for itself.
In doing so they developed their language without knowing that other
communities were working out the same problems for themselves. So
they first developed their own sign and gesture language and later
on their word or sound language and kept on using it. While they may
thus have developed the use of some of the same signs and sounds or
combination of sounds to express one thing perfectly understandable to
themselves, these sounds or combinations of sounds might mean something
entirely different to another community, where that particular sound or
combination of sounds may have been hit upon to mean something entirely
different.

Of course, not all languages were developed in this way. There are,
you know, a great many languages used in the world. Some of them are
offshoots of others, where part of a community moved to another part of
the world, taking their language with them, but developing it further
along new lines, and using new combinations of sounds for new words.
Then also, there are many words which mean the same thing in different
languages and are spoken with practically the same sounds. This is due
to the movement of people from one nation to another and bringing their
own words with them, so to speak. In many instances a stranger would
come to another nation, and use his own word for expressing a certain
thing and that would eventually be taken up and used as a better word,
and the old word dropped. It is strange that this should be true, but
this accounts for the fact that many words are the same in sound and
meaning in numerous languages.




What Makes a Match Light When We Strike It?


The match lights when we rub it along a rough substance, because the
rubbing produces sufficient heat on the end of the match to set fire
to the head, as we call it, which is made of chemicals that light more
easily than the stick of wood, which is the rest of the match. The fire
thus started is hot enough and burns long enough to set fire to the
wooden part of the match.

To explain this more fully, let me say this. Rub your finger quickly
along your coat sleeve or along the seat of your trousers, long a
favorite place for men to strike matches, pretending that your finger
is a match. You find the end of your finger becomes warm, don’t you?
Not warm enough to set your finger on fire, of course, but if you had
the same combination of chemicals on the end of your finger that there
is on the match, you would set the chemicals afire and this would burn
your finger, just as it sets fire to the wooden part of the match.

It took a great many years to discover the combination of chemicals of
which the head of the match is made. Before that discovery was made it
was far from easy to light the light in the evening as it is now. It
must have been a serious thing to let the fire go out in the furnace in
those days.




What Makes the Kettle Whistle?


The kettle whistles only when the water boils and the steam or gas
which is the form the water turns into when boiling is trying to
escape through the spout of the kettle. You see, when the water starts
boiling, the inside of the kettle is at once filled with steam and more
is coming out of the water all the time. This steam must get out some
way, so it rushes for the spout of the kettle, and because so much of
it is trying to get out of a comparatively small opening at once there
is quite a pressure and this results in making the whistle out of the
spout of the kettle. It is just the same process as when you whistle
yourself. To whistle you fill your mouth with air and force it out
through your lips, which you have closed excepting for a small opening,
by the pressure you can bring to bear with the roof and sides of your
mouth, and if you have learned to make your lips into the proper shape
and apply the pressure steadily you can sound a very long note and make
different notes by making the opening in your lips large or small. The
kettle spout has only one size of opening so the sound is practically
the same at all times though louder at sometimes than at others. This
is caused by the varying pressure at which the steam in the kettle is
being forced out.




What Makes the Water From a Fountain Shoot Into the Air?


The water from the fountain shoots into the air because water anywhere
will run down if given a chance. To produce a fountain you must have
a source of water supply for the fountain which is higher than the
openings of the fountain out of which the water shoots. The water comes
out of the holes in the fountain for the same reason that it comes out
of the faucet in the kitchen or bath room. In the latter case the water
comes from the waterworks reservoir in which the level of the water is
much higher than the opening in the faucet in your home. Being higher
the water in the reservoir is trying to get away through the pipes all
the time and all the pipes leading from the reservoir are full of this
water trying to get away. Just as soon as you turn the valve in the
faucet the water comes out and runs down into the bowl.

If you were to turn the opening of the faucet up instead of down as
it is, the water would shoot up instead of down. Not very much, it
is true, but it would act much like the water from the fountain. The
reason it does not shoot up high in the air like a fountain is because
the opening in the faucet is the same size as the opening in the
little pipe which leads the water from the street into the house. If
you would turn the opening of the faucet up and attach to it a pipe
which made the opening much smaller (the size of the opening in the
fountains), you would see the water shoot into the air just as it does
from the fountain. When you reduce the size of the opening you increase
the pressure of the water coming from the pipes in proportion to the
reduction you have made in the size of the opening.

Water from the fountain will not, however, shoot as high as the level
of the water in the reservoir because, as soon as it leaves the pipes,
it encounters the pressure of the air outside the pipes and the law of
gravitation which pulls all things toward the center of the earth.

It is not natural for water to shoot into the air as it does in a
fountain. The only way water can go naturally is down, and it only goes
up a little way from a fountain because of the pressure of the water in
the pipes behind the openings in the pipes in the fountain.




What Keeps a Balloon Up?


A balloon stays up in the air, because of the air in it, together with
the weight of the balloon, is less than an equal bulk of the air in
which it floats.

In former days of ballooning the balloons were filled with hot air and
were then found to rise and stay up until the air inside of the balloon
became of the same temperature as that in which it floated. When this
stage was reached, the balloon itself would fall because the material
of which it was made was denser than air.

Today balloonists fill their balloons with gas which is lighter than
air, even when as cool as the air in which they rise and are thus able
to stay up a long time.

You, of course, have seen many of the red, white and blue paper
balloons which are sent up on the Fourth of July. You will remember
that father, or whoever it is that is sending them up, lights the
oil-soaked knot of cloth that is attached to the balloon immediately
below the opening at the bottom. He first lights this and then holds
the balloon for a time with his hands.

Soon, however, you will remember that the balloon starts upward with
father still holding it. This is because the air inside the balloon
is becoming heated. You will notice also that at first he has to hold
out the sides of the top of the balloon with his hands or has some
one help him do this, but that even so the balloon does not stand out
round and full as it should. When the balloon starts to rise, however,
you will notice that it is round and full. This is because the air in
the balloon has become heated and is expanding. Soon the balloon is
tugging to get away and father lets go and it rises and sails away with
the wind. As long as the fire below it burns, and if the wind does not
upset it so as to make the paper part catch fire, the balloon will stay
up; but, when the fire burns out, the balloon will come down.

The balloon merely rises because the air inside, and held there by the
covering of the balloon, is warmer air and lighter than the air on the
outside.




Why Did People of Long Ago Live Longer Than We Do Now?


When reading of people who lived long years ago and especially when
reading about the length of their lives, we are told that in the old
days people lived longer than they do now. Some of the early historical
records speak of single individuals who lived hundreds of years. There
is great doubt as to whether these statements are founded on fact. In
thinking about this we must first take into consideration that these
records of long ages were recorded at a time when man had no accurate
ideas of the actual passage of long periods of time such as a year.
They did not have our calendar as a basis for figuring at all. Learned
men now tell us that the actual age of men who lived at the time these
records of great ages were recorded probably lived shorter lives
than we do now, and that what they record as a period of one year was
probably a much shorter period than one year.

It is true beyond the question of a doubt that the people of today live
longer on the average than people who lived ten, twenty or more years
ago.

In other words, the average period of life has increased steadily.
This is due to the fact that we have taken great care of our bodies;
have improved the conditions in which we live, and made them more
sanitary; have learned to fight and check and eradicate diseases, which
only a few years ago we could not prevent people dying of when they
once contracted them, and we know from the records which we keep that
actually people live longer on the average today than only a few years
ago, and it is safe to say that they live longer now on the average
than at any time in the world’s history.




Is There a Reason for Everything?


The world is so constructed that there must be a reason or cause for
everything. There are so many forces in the world that man has not yet
been able to locate the original cause of every one of them. Concerning
other things, he sees the effects without having any knowledge of the
forces which are their cause. Other things he has never even bothered
to inquire about, but simply takes them for granted. But every force,
which means, of course, everything in the world, must have had a
beginning and therefore something or a combination of things must have
caused it to begin, and the thing or things that caused it to be is the
reason for its being. Every little while someone makes a discovery of
some new force, and then we suddenly realize that this force has been
in existence all the time although not known to man, and we discover
through this the reason for many other things being as they are.

The other thing or side of the question is also true. We cannot have
a cause without an effect. You cannot do anything without causing
something to happen and producing an effect on one or more other
objects either animate or inanimate. You cannot move your hand without
creating some disturbance in the air. When you make a noise, low or
loud, you produce sound waves. When you burn a stick of wood, you
create smoke, ashes and gases of various kinds. You change the whole
nature of what was the piece of wood, and yet no particle of what made
the stick of wood is ever destroyed or lost, but appears in some other
thing in the air or on or in the earth.




What Makes an Echo?


An echo is caused when the waves of air which you create when you shout
are thrown back again when they are stopped by something they encounter
and are turned back without changing their shape. Any kind of a sound
wave will make an echo in this way.

You see, you can have no sound of any kind without sound waves. You
could not make a sound if there were no air. Now, when you shout, you
start a series of sound waves that go out from you in every direction
and they spread away from you in circles just like the rings of ripples
that are caused when you drop a stone into a pool of water. You can
prove this to yourself easily by having one, two, three or more of your
friends stand around you in a large circle. You can place them as far
away from you as your shout can be heard if you wish. When you shout,
each of your friends will hear the shout at the same time, provided, of
course, they are at equal distances from you.

Sometimes these sound waves as they go away from you in circles strike
objects that turn the waves back unbroken just as they came to them.
The waves will bounce back just like a rubber ball from a wall against
which it has been thrown and this is the echo. However, some things
that the sound waves strike break up these waves entirely and others
partially.

No doubt you have sometimes noticed when you shout you hear a distinct
echo and that at other times, standing in the same place, you cannot
hear any echo, although you shout in the same way. This is explained by
the fact that at times conditions of the air are such that no echo is
produced while at other times a perfect echo results.




What is a Whispering Gallery?


The possibilities of an echo have to be taken into account by the
architects and builders of all public buildings, such as theaters,
halls and churches, where anyone is to speak or entertain others.
Unless they are very careful the walls and ceilings may be so arranged
that when any one sings or speaks in the room, there is such an echo
that it interferes with the music or speaking. It sometimes happens
also that through some peculiarity in which the walls and ceiling of
a building are constructed there will be certain places in the room
where an echo can be heard, even a whisper, and which cannot be heard
in other parts of the room at all. This is likely to occur in rooms
where there is a dome-shaped ceiling. There will be certain spots in
the room hundreds of feet apart, where if you stand on one spot and
another person is on another definite spot clear across the room, the
tiniest whisper can be heard, while the people in between cannot hear
at all. This is called a whispering gallery. Of course, loud talking
would produce the same effect. A whispering gallery is a gallery with
an echo which can be heard from certain positions. There are a number
of famous whispering galleries of the world. In the room beneath the
great dome of our Capitol at Washington is an almost perfect whispering
gallery. There are quite a number of points at which you can stand and
hear the whispers across the room which is more than a hundred feet.
These whispering galleries come accidentally, of course. It would be
difficult to deliberately construct a building in such a way as to
produce a whispering gallery.




Why Do We Get a Bump Instead of a Dent When We Knock Our Heads?


When you knock your head against a sharp corner, or if some one hits
you on the head with anything with a sharp edge, you do receive a dent
in your head, but it does not last. In other words, the head has one of
the qualities of a rubber ball. You can press your finger against the
sides of the rubber ball and push it in, but when you take your finger
off the ball resumes its shape. Just so with your head--it resumes its
shape after a blow.

After doing this, however, a bump or lump is formed. I will endeavor to
tell you how the bump is formed or rather what causes it to form. You
cannot knock your head against anything that is harder than your head
without causing some injury to the parts which received the bump. Now,
what happens then is just what happens to any other part of your body
when it is injured whether as a result of a bump, a cut or a bee or
mosquito sting.

As soon as the injury occurs the brain starts the “repair crew” to
work. The result is that first a great supply of blood is rushed to the
injured part with the result that the blood vessels are filled up and
extended with blood. Certain parts of the blood cells find their way
through the walls of the blood vessels at the part of the injury and
other fluids from the body are piled up there, so to speak, to form a
congestion. This “piling up or congestion” distends the skin and raises
the bump. On the head where the layer of muscular structure is thinner
and where there is less space between the bones of the skull and the
outside skin, the bump will be larger and more noticeable, because a
good deal of blood and other fluids are piled up in a comparatively
small space, and so the skin gets pushed out further to accommodate
this great congestion, whereas in other parts of the body the bump may
be quite as large but not so noticeable.

[Illustration: HOW MEN GO DOWN TO THE BOTTOM OF THE SEA

PUTTING ON THE SUIT.

Socks, trousers and shirt in one, and a copper breastplate.]

[Illustration: PUTTING ON THE IRON-SOLED SHOES.

They are purposely made heavy, to help the diver sink.]




The Deep Sea Diver


What Does the Bottom of the Sea Look Like?

It looks very much like the land on which we live. There are mountains
and valleys, rocks and crags, trees and grass, just the same as we see
on land, except, of course, that there are no human beings to be seen.
Instead of birds flitting about the tree-tops, fish swim about them,
and where the squirrel and rabbit bound through the woods on land, the
great king crab and sea turtle drag their unwieldy forms on the ocean’s
bottom. Some of the scenes at the bottom of the sea are like fairyland,
and in tropical waters are often as beautiful and spectacular as those
we see in theatrical pantomimes. Delicately tinted sea-shells, great
trees of snow-white coral, sea foliage of every tint and shape, and
deep dark caverns, in which lurk the devil-fish and other odd looking
fish.


The Diver’s Outfit.

The armor of to-day consists of a rubber and canvas suit, socks,
trousers and shirt in one, a copper breastplate or collar, a copper
helmet, iron-soled shoes, and a belt of leaden weights to sink the
diver.

[Illustration: ADJUSTING THE TELEPHONE.

This enables the diver to talk at all times to those above him.]

[Illustration: PUTTING ON THE HELMET.

It is made of tinned copper, with three glass-covered openings, to
enable the diver to look out.]

[Illustration: TELEPHONING FROM THE BOTTOM OF THE OCEAN

TESTING THE TELEPHONE.

Every precaution is taken to see that everything is in order before the
diver goes down.]

[Illustration: THE FINAL TEST.

The least error in the adjustment may mean death to the diver.]

The helmet is made of tinned copper, with three circular glasses, one
in front and one on either side, with guards to protect them. The
front eye-piece is made to unscrew and enable the diver to receive
or give instructions without removing the helmet. One or more outlet
valves are placed at the back or side of the helmet to allow the
vitiated air to escape. These valves only open outwards by working
against a spiral spring, so that no water can enter. The inlet valve
is at the back of the helmet, and the air on entry is directed by
three channels running along the top of the helmet to points above the
eye-pieces, enabling the diver to always inhale fresh air. The helmet
is secured to the breastplate below by a segmental screw-bayonet joint,
securing attachment by one-eighth of a turn. The junction between the
water-proof dress and the breastplate is made watertight by means of
studs, brass plates and wing-nuts.

A life or signal-line and also a modern telephone enables the diver to
communicate at all times with those above him.

The cost of a complete diving outfit ranges from $750.00 to $1,000.00.
The weight of the armor and attachments worn by the diver is 256
pounds, divided as follows: Helmet and breastplate, 58 pounds; belt of
lead weights, 122 pounds; rubber suit, 19 pounds; iron-soled shoes, 27
pounds each.

The air which sustains the diver’s life below the surface is pumped
from above by a powerful pump, which must be kept constantly at work
while the diver is down. A stoppage of the pump a single instant while
the diver is in deep water would result almost in his instant death
from the pressure of the water outside.

The greatest depth reached by any diver was 204 feet, at which depth
there was a pressure of 88¹⁄₂ pounds per square inch on his body. The
area exposed of the average diver in armor is 720 inches, which would
have made the diver at that depth sustain a pressure of 66,960 pounds,
or over 33 tons.

The water pressure on a diver is as follows:

   20 feet         8¹⁄₂ lbs.
   30 feet        12³⁄₄ lbs.
   40 feet        17¹⁄₄ lbs.
   50 feet        21³⁄₄ lbs.
   60 feet        26¹⁄₄ lbs.
   70 feet        30¹⁄₂ lbs.
   80 feet        34³⁄₄ lbs.
   90 feet        39    lbs.
  100 feet        43¹⁄₂ lbs.
  120 feet        52¹⁄₄ lbs.
  130 feet        56¹⁄₂ lbs.
  140 feet        60³⁄₄ lbs.
  150 feet        65¹⁄₄ lbs.
  160 feet        69³⁄₄ lbs.
  170 feet        74    lbs.
  180 feet        78    lbs.
  190 feet        82¹⁄₄ lbs.
  204 feet        88¹⁄₂ lbs.

The dangers of diving are manifold, and so risky is the calling that
there are comparatively few divers in the United States. The cheapest
of them command $10.00 a day for four or five hours’ work, and many of
them get $50.00 and $60.00 for the same term of labor under water.

The greatest danger that besets the diver is the risk he runs every
time he dives of rupturing a blood-vessel by the excessively compressed
air he is compelled to breathe. He is also subject to attacks from
sharks, sword-fish, devil-fish, and other voracious monsters of
the ocean’s depths. To defend himself against them, he carries a
double-edged knife as sharp as a razor. It is the diver’s sole weapon
of defense.

Just how far back the art of submarine diving dates is a matter of
conjecture, but until the invention of the present armor and helmet,
in 1839, work and exploration under water was, at best, imperfect, and
could only be pursued in a very limited degree.


Feats of Divers.

~THE GREATEST DIVING FEAT~

Millions of dollars’ worth of property has been recovered from the
ocean’s depth by divers. One of the greatest achievements in this line
was by the famous English diver, Lambert, who recovered vast treasure
from the “Alfonso XII,” a Spanish mail steamer belonging to the Lopez
Line, which sank off Point Gando, Grand Canary, in 26¹⁄₂ fathoms of
water. The salvage party was dispatched by the underwriters in May,
1885, the vessel having £100,000 in specie on board. For nearly six
months the operations were persevered in before the divers could reach
the treasure-room beneath the three decks. Two divers lost their lives
in the vain attempt, the pressure of water being fatal. The diver
recovered £90,000 from the wreck, and got £4,500 for doing it.

One of the most difficult operations ever performed by a diver was the
recovering of the treasure sunk in the steamship “Malabar,” off Galle.
On this occasion the large iron plates, half an inch thick, had to be
cut away from the mail-room, and then the diver had to work through
nine feet of sand. The whole of the specie on board this vessel--upward
of $1,500,000--was saved, as much as $80,000 having been gotten out in
one day.

It is an interesting fact that from time to time expeditions have been
fitted out, and companies formed, with the sole intention of searching
for buried treasure beneath the sea. Again and again have expeditions
left New York or San Francisco in the certainty of recovering tons of
bullion sunk off the Brazilian coast, or lying undisturbed in the mud
of the Rio de la Plata.

[Illustration: The last look just before going down.]

[Illustration: Coming up after a successful trip.]

At the end of 1885, the large steamer Imbus, belonging to the P. & O.
Co., sank off Trincomalee, having on board a very valuable East-India
cargo, together with a large amount of specie. This was another case
of a fortune found in the sea, for a very large amount of treasure was
recovered.

Another wreck from which a large sum of gold coin and bullion was
recovered by divers, was that of the French ship “L’Orient.” She
is stated to have had on board specie to the value of no less than
$3,000,000, besides other treasure.

A parallel case to “L’Orient” is that of the “Lutine,” a warship of
thirty-two guns, wrecked off the coast of Holland. This vessel sailed
from the Yarmouth Roads with an immense quantity of treasure for the
Texel. In the course of the day it came on to blow a heavy gale; the
vessel was lost and went to pieces. Salvage operations by divers,
during eighteen months, resulted in the recovery of £400,000 in specie.

Humorous scenes do not play much of a part on the ocean’s bottom, and
the sublime and awe-inspiring are far more in evidence there than the
ludicrous, yet even beneath the waves there are laughable scenes at
times. A diver had been engaged to inspect a sunken vessel off the
coast of Cuba. Arriving on the scene he discovered a number of native
sponge-divers, who descend to considerable depths, diving down from
their canoes to the sunken vessel trying to pick up something of value.
They paid little attention to the arrival of the wrecking outfit, and
did not notice the diver descend, until suddenly what seemed to them to
be a horrible human-shaped monster, with an immense head of glistening
copper and three big, round, glassy eyes, came walking around the
vessel’s bow and made a big salaam to them. That was enough. They shot
surfaceward like sky-rockets, climbed frantically into their canoes and
hurriedly rowed away.




What Happens When Anything Explodes?


By explosives are meant substances that can be made to give off a large
quantity of gas in an exceedingly short time, and the shorter the time
required for the production of the gas the greater will be the violence
of the explosion. Many substances that ordinarily have no explosive
qualities may be made to act as explosives under certain circumstances.
Water, for example, has caused very destructive boiler explosions when
a quantity of it has been allowed to enter an empty boiler that had
become red hot. Particles of dust in the air have occasioned explosions
in saw mills, where the air always contains large quantities of dust.
A flame introduced into air that is heavily laden with dust may cause
a sudden burning of the particles near it, and from these the fire may
be conveyed so rapidly to the others that the heat will cause the air
to expand suddenly, and this, together with the formation of gases from
the burning, will cause an explosion.

It must not be thought, however, that fine sawdust or water would
ordinarily be classed as explosives. The term is generally applied only
to those substances that may be very easily caused to explode.

The oldest, and most widely known, explosive that we possess is
gunpowder, the invention of which is generally credited to the Chinese.
It is a mixture of potassium nitrate, or saltpeter, with powdered
charcoal and sulphur. The proportions in which these substances are
mixed vary in different kinds of powder, but they usually do not differ
much from the following:

  Sulphur        10 per cent.
  Charcoal       16 per cent.
  Saltpeter      74 per cent.

The explosive quality of gunpowder is due to the fact that it will burn
with great rapidity without contact with the air, and that in burning
it liberates large volumes of gas. When a spark is introduced into it,
the carbon, charcoal, and sulphur combine with a portion of the oxygen
contained in the saltpeter to form carbonic acid gas and sulphurous
acid gas, and at the same time the nitrogen contained in the saltpeter
is set free in the gaseous form. This action takes place very suddenly,
and the volume of gas set free is so much greater than that of the
powder that an explosion follows.

In the manufacture of gunpowder all that is absolutely necessary is to
mix the three ingredients thoroughly and in the proper proportions.
But to fit the powder for use in firing small arms and cannon it is
made into grains of various sizes, the small sizes being used for the
small arms with short barrels, and the large sizes for cannon. The
reason for this is that if the powder is made in very small grains it
all burns at once, and the explosion takes place so suddenly that an
exceedingly strong gun is required to withstand the explosion, while if
larger grains are employed the burning is slower and continues until
the projectile has traveled to the muzzle of the gun. In this way the
projectile is fired from the gun with as much force as if the explosion
had taken place at once, but there is less strain on the gun.




What Causes the Smoke When a Gun Goes Off?


Powder of this latter kind always produces a considerable quantity of
smoke when it is fired, because there is a quantity of fine particles
formed from the breaking up of the saltpeter and from some of the
charcoal which is not completely burned. This smoke forms a cloud that
takes some time to clear away, which is a very objectionable feature.
In order to get rid of it, efforts were made to produce a substance
that would explode without leaving any solid residue, and that could be
used in guns. These efforts were finally successful, and there are now
several brands of smokeless powder in use.




What is Smokeless Powder Made Of?


The most satisfactory forms of smokeless powder are all made from
guncotton or nitrocellulose. This substance, which is made by treating
cotton with a mixture of nitric and sulphuric acids, is a chemical
compound, not a mixture like gunpowder; and when it is exploded it is
all converted into gases, of which the chief ones are carbonic acid
gas, nitrogen, and water-vapor. To cause the explosion of guncotton it
is not necessary to burn it, but a mere shock or jar will cause it to
decompose with explosive violence. Of course, such a violent explosive
as this could not be used either in small arms or in cannon, but
guncotton can be converted into less explosive forms which are suitable
for use in guns, and the majority, of smokeless powders are made in
this way. The methods used in producing the smokeless powders are kept
secret by the various countries that use them.




What is Nitroglycerine?


Another very powerful explosive, which is closely related to guncotton,
is nitroglycerine. This compound is made by treating glycerine with the
same sort of acid mixture that is used in making guncotton. It explodes
in the same way that guncotton does and yields the same products. It is
an oily liquid of yellow color, and on account of its liquid form it is
difficult to handle and use. The difficulty in handling nitroglycerine
led to the plan of mixing it with a quantity of very fine sand called
infusorial earth. When mixed with this a solid mass called dynamite is
formed, which is easier to handle and more difficult to explode, but
which has almost as much explosive force as nitroglycerine.

A more powerful explosive than either nitroglycerine or guncotton is
obtained by mixing them together. When this is done the guncotton
swells up by absorbing the nitroglycerine and becomes a brownish,
jelly-like substance that is known as blasting gelatin. This is
generally considered the most powerful explosive obtainable.




What Makes Nitroglycerine and Guncotton Explode So Readily?


Let us now consider for the moment what it is that makes guncotton,
nitroglycerine, and blasting gelatin explode so readily. The
explanation is found in the presence in them of nitrogen. As you
remember from what you learned about air, nitrogen is an extremely
inactive element. It has no strong tendency to combine with other
elements, and when it does enter into combination with them the
compounds formed are almost always easily decomposed. In the compounds
that have just been described a shock causes a loosening of the bonds
that hold the nitrogen, and the whole compound goes to pieces just as
an arch falls when the keystone is removed.




What Is Silver?


Since the earliest time recorded in history, silver has been the
most used of the precious metals, both in the arts and as a medium
of exchange. Even in the prehistoric times silver mines were worked
and the metal was employed in the ornamental and useful arts. It was
not so early used as money, and when it began to be adopted for this
purpose, it was made into bars or rings and sold by weight. The first
regular coinage of either gold or silver was in Phrygia, or Lydia,
in Asia Minor. Silver was used in the arts by the Athenians, the
Phœnicians, the Vikings, the Aztecs, the Peruvians, and in fact by all
the civilized and semi-civilized nations of antiquity. It is found
in almost every part of the globe, usually in combination with other
metals. The mines in South America, Mexico, and the United States are
especially rich. Silver is sometimes found in huge nuggets. A mass
weighing 800 pounds was found in Peru, and it is claimed that one of
2,700 pounds was extracted in Mexico. The ratio of the value of silver
and gold has varied greatly. At the Christian era it was 9 to 1; 500
A.D. it was 18 to 1; but in 1100 A.D. it was only 8 to 1. In 1893
it was as high as 2,577 to 1. The subject has entered largely into
American politics as a disturbing element, and in 1896 the Democratic
party, in its national convention, declared for the free coinage of the
metals at 16 to 1. The Republican party adhered to the gold standard
and declared against the free coinage of silver. Each party reaffirmed
in 1900 this plank in its platform. In both years the Democrats were
defeated.




What Is Worry?


Worry is a feeling of fear, but is never of the present. It is always
about something that may happen or that has happened. It is generally
in the future, sometimes in the past, but never in the present.

An animal that knows neither future nor past cannot worry. Babies,
living only as they do in the present, cannot worry. All creatures,
excepting human beings, live only in the present and therefore they do
not worry, for such creatures cannot remember what happened in the past
or guess what is going to happen.

A human being after arriving at a certain age is given such powers
that his mind can go back to the past and cast itself forward into the
future as he thinks it will be, because he has imagination. As a matter
of fact we live less in the present than in the past or future.




Why Do We Worry?


We worry because we are able through a power called self-consciousness
to place ourselves through our minds for the time being. Either--back
somewhere in the past without carrying our physical bodies with us; for
if we could take our bodies with us, we would be in the present again,
and then worry is impossible; or, we use our imagination and project
the future entirely apart from our bodies, for we cannot project our
bodies into the future, and if we could we would again be in the
present. We worry over going to have an operation performed which may
or not be dangerous, but quite necessary. We may still think we worry
when the operation begins, but as soon as that occurs the time becomes
the present, and though we may fear, we cannot worry in the present.

[Illustration:

  _Back View of Shield_

  _Longitudinal Section through Shield & Tunnel_

  _Diagram showing method of tunnel construction by shield and
  compressed air._

  _Scale; ¹⁄₈ inch · 1 foot_

  _Jacobs & Davies Inc. 30 Church St. N.Y._

  _Oct. 15. 1910._

FIGURE 1.]




The Story in a Tunnel


How a Tunnel Is Dug Under Water.

Fig. 1. On the left is a cross section showing, in diagram, the back
view of a shield. The heavy black circle is the “tail” or “skin.”
The small circles within the tail are the hydraulic rams which at a
pressure of 5,000 pounds to the square inch force the shield forward.
The square compartments within the shield are the openings through
which the men pass to dig away the ground. In the middle of the shield
is shown the swinging “erector” which picks up the iron lining plates
and puts them in position.

The view on the right is a longitudinal section of the tunnel showing
the shield and the bulkhead wall across the tunnel with the air locks
built into it. The front of the shield ahead of the doors is made with
a sharp edge called the “cutting edge” and this makes it easier for the
shield to advance in case all the ground in front has not been removed.
This view shows how the tail overlaps the last portion of the iron
lining.

Some distance behind the shield comes the concrete bulkhead wall with
the air locks contained in it. There are two shown in the view. The
upper one is the emergency air lock, always kept ready so that in case
of an accident the men have a means of escape even though the lower
part of the tunnel is filled with rushing water or mud. The lower air
lock is for the passage of men and materials during ordinary working.
This view also shows that all the tunnel ahead of the bulkhead wall
is under compressed air while the finished tunnel behind the bulkhead
wall is under the ordinary or normal air pressure. When the tunnel is
finished the air locks and bulkhead walls are removed.

[Illustration: FRONT VIEW OF A DRIVING SHIELD

This shows the front of one of the shields used on the Pennsylvania
Railroad tunnels crossing the North River at New York. The cutting edge
is clearly seen and the various compartments, each with its door, which
divide up the front of the shield. These shields weighed about 200 tons
each.]


HOW TUNNELS ARE BUILT.

These notes describe very generally the way in which tunnels are built
through mud and gravel under parts of the sea or large rivers in such
a way that the men who build them are protected and as safe as the
carpenter who is building a house.

The way these tunnels are built is called the “shield” way because
the machine used is called a shield. It is given this name because it
shields the tunnel builders from the water and the mud which are ready
at every moment to overwhelm them and kill them.

The shield was invented in 1818 by a great Engineer, Marc Isambard
Brunel, who was a Frenchman living in England. The idea of the shield
came to him as he saw how the sea worm which attacks the wooden piles
of docks along the shore bores the holes it makes in the wood. The head
of this worm is very hard and can bite its way through the hardest
woods. As it goes through the wood its body makes a hard shelly coating
which lines the holes which its head has made and prevents the hole
from getting filled up. This is the general idea of a tunnel built by a
shield.

The first shield was used by Mr. Brunel to make a tunnel across the
Thames River at London, England. This is still the biggest tunnel
ever built by a shield, although not the longest, and is still
used by railroad trains. This tunnel was begun in 1825 and was
finished in 1843, and provides a history of almost unexampled and
not-to-be-excelled courage in attacking difficulties and skill in
defeating them.

Since the days of Brunel many great improvements have been made in the
shield and in the way of working it but the same idea is still there.

[Illustration: HOW THE SHIELD IS PUSHED FORWARD

This shows the rear end or tail end of one of the smaller shields, used
on the Hudson and Manhattan Railroad tunnels under the North or Hudson
River at New York. It shows the skin, the hydraulic jacks within the
skin and the piping and valves for working them. It also shows the
doors leading to the front or “face.” The erector is not shown, but the
circular hole in the middle shows where it would be attached.]

[Illustration: This shows one side of an air lock bulkhead wall with
the air lock in place. The boiler-like appearance of the lock is
clearly visible, as well as the door and the pressure gauge to tell the
air pressure inside the lock.]

[Illustration: This is a rear view of one of the Pennsylvania Tunnel
shields, taken after a length of tunnel had been completed. All the
details of construction are shown, but in this case the erector is
clearly seen also. The valves which control the erector and the rams
which push the shield forward are seen near the top of the shield. The
rods across the tunnel are turn-buckles used to keep the iron lining
from getting out of shape in the soft mud. These are removed later. The
floor and tracks in the bottom are temporary and are used for bringing
materials to and from the shield.]

After the days of Brunel’s shield another great help was given to
tunnel builders by the invention of the use of compressed air to hold
back the water which saturates the ground in which the tunnel is being
built.

~WHO INVENTED THE COMPRESSED AIR METHOD~

The first real invention of compressed air for this purpose was made
by Admiral Sir Thomas Cochrane who, in 1830, took out a patent for the
use of compressed air to expel the water from the ground in shafts and
tunnels and, by this means, to convert the ground from a condition of
quicksand to one of firmness. This patent covers all the essential
features of compressed air working.

As suggested above, the thing which compressed air does in a tunnel
is to push the water out from all the spaces which it fills in the
ground, so that the men who are digging away the ground for the tunnel
are working in firm dry ground instead of a mixture of earth and water
which will run into and fill the hole they dig as soon as it is dug.

Whenever a tunnel is being built below a body of water through ground
which is porous, or in other words through any ground except solid
rock or dense clay, the water fills every crevice and space in the
ground and is exerting a pressure of about half a pound per square inch
above the ordinary pressure of the air, (which is 15 pounds to the
square inch) for every foot of depth below the surface of the water;
so that supposing the tunnel is 40 feet below the water the water has
a pressure of nearly 20 pounds per square inch on every square inch
of the surface of the tunnel. This pressure causes the water to flow
violently into any hole or opening that is made in the ground, and,
unless the water is prevented from moving by some means or other, the
opening made would be very quickly filled with water and also with
ground as the rush of water will carry the sand, gravel or mud with it.

By Cochrane’s invention the whole tunnel is filled with air under
a pressure equal to the pressure of the water. This compressed air
therefore balances the pressure of the water and holds it back from
moving, and if the pressure of the air is made slightly greater than
that of the water the water is driven back from the tunnels for a short
distance so that when the tunnel is being dug the ground instead of
being wet is quite dry.

This explains the principles of the shield and compressed air way of
making a tunnel.

The following describes very shortly how these principles are put to
actual use.

Most tunnels which are built by shield and compressed air under rivers
or arms of the sea are lined with cast iron plates to protect the
railway or roadway which is in the tunnel.

The tunnel is a circular tube, or shell, and the plates have flanges
on all sides which are bolted together. This shell is put into place,
plate by plate, by means of the shield which not only protects the
workmen and the work under construction, but which helps to build the
iron shell. In fact it corresponds to the sea worm which bores through
the wood and lines the hole with a shell. In the case of the tunnel
the shell is made of iron. The shield itself consists of a steel tube
or cylinder slightly bigger in diameter than the tube or tunnel it
is intended to build. The front edge of this shield is made up of a
ring of sharp edged castings which form what is called the “cutting
edge.” Just behind the cutting edge is a bulkhead or wall of steel, in
which are openings which may be opened or closed at will. Behind this
bulkhead are placed a number of hydraulic jacks or presses arranged
around the shield and within it, so that by thrusting against the last
erected ring of iron lining the whole shield is pushed forward. The
rear end of the shield is a continuation of the cylinder which forms
the front end, and this part, called the “tail,” always overlaps the
last few feet of the built up iron shell.

[Illustration: This is a photograph of a model of the Pennsylvania
Tunnels to New York City, made for the Jamestown Tercentenary
Exposition of 1907. It is given because it illustrates, as no
photograph of actual work could do, the relationship between the
shield, the tunnel itself and the air lock. This view shows the rear
part of the shield on the extreme left, with the erector picking up an
iron plate. It shows a man bringing a car with two of the iron plates
up to the shield. Behind this man comes the bulkhead wall with the
emergency air lock in the top and the ordinary air lock for passing
in and out at the bottom. It also shows the upper platform to the
emergency lock along which the men can get to the emergency lock in
case of an accident.]

[Illustration: This is another view of the same model, but showing the
front view of the shield. The doors on the air locks are clearly shown.]

[Illustration: This is a photograph taken in one of the Pennsylvania
tunnels under the Hudson River. It shows the soft mud, through which
the tunnel is being built, flowing in a thick stream through one of
the doors of the shield. The mud under the Hudson, where these tunnels
are, is so soft that often the shield was pushed through the mud with
all the doors shut, so that no mud came into the tunnel and no digging
had to be done, but the shield pushed its way bodily through the mud,
the rings of iron lining being built up behind as usual. Generally,
however, a certain amount of mud was brought in and had to be removed.
This photograph shows how it looked.]

~HOW THE SHIELD CUTS THROUGH THE GROUND~

The diagram, Fig. 1, shows more clearly what is meant. From an
inspection of Figure 1 it is clear that, when the openings in the
shield bulkhead are closed, the tunnel is protected from an inrush
of either water or earth; the openings in the bulkhead may be so
regulated that control is maintained over the material passed through.
After a ring of iron lining has been erected within the tail of the
shield, the shield doors are opened and men go through them and dig
out enough earth for the shield to go ahead. The rams are then thrust
out thus pushing the shield ahead. Another ring of iron is built up
within the tail for which purpose an hydraulic swinging arm, called the
“erector,” is mounted on the shield face. This erector picks up the
plates and puts them into position, one by one, while the men bolt them
together. Excavation is then carried on again and the whole round of
work repeated, gaining every time the jacks are rammed or thrust out
a length equal to the length of one ring of iron lining. In carrying
out this work in ground charged with water the shield is assisted by
introducing compressed air as described before. To use the compressed
air thick bulkhead walls of masonry are built across the tunnel behind
the shield and into the space between the shield and the bulkhead wall
air is pumped, compressed to the same pressure as that of the water in
the ground, or in other words the pressure of the air in pounds per
square inch is about half the number of feet the tunnel is below the
water surface. This dries the ground and simplifies enormously the
difficulty of working in it. The diagram, (Fig. 1) shows a bulkhead
wall across the tunnel. In order to pass from the ordinary air outside
the bulkhead into the compressed air inside it, all the men and the
materials have to pass through the “air locks” which are built into
the wall. They are called air locks because they are like the locks on
a canal which raise the water from a lower to a higher level or lower
it from a higher to a lower level as the case may be. The difference
is that an air lock enables one to pass from air at a low pressure to
one of a higher, or vice versa. An air lock is made like a large boiler
with a door at each end. If we wish to enter the compressed air we
enter the lock from the outside. The door at the end has been tightly
closed to prevent the compressed air from rushing out. We close the
door behind us and are now tightly shut in the boiler-like lock. We now
open a valve and compressed air begins to flow quickly into the air
lock and the air gets hotter and hotter, due to the compression of the
air. Very likely an intense pain begins to make itself felt in the ears
but by swallowing hard and blowing the nose it may be relieved. It is
caused by the air pressure being greater on the outside of the ear drum
than on the inside. If the delicate ear passages are choked, because
of a cold or some such reason, it is unsafe to go further or the ear
drum may burst. When the pressure in the air lock has reached that in
the working chamber, the door leading to the shield may be opened and
we can pass to the working space and note the work going on. There is
no especial bodily sensation to be felt except a slight exhilaration
and it is curious to find that one cannot whistle. On leaving the
compressed air we enter the air lock by the door we left; a valve is
turned and the air begins to escape and the pressure in the air lock
begins to go down. As it does so the air becomes colder and colder
and the whole lock is filled with a wet fog due to the chilling by
expansion of the air. The air has to be allowed to escape very slowly,
as bubbles of air and gas otherwise form in the blood vessels and
tissues of the body giving rise to the very painful complaint known to
tunnel builders as “the bends,” and in very serious cases to paralysis
and even death. The higher the air pressure the more slowly must one
come out into the ordinary air.

[Illustration: MAKING THE JOINTS WATER TIGHT

This shows the erector building up the iron lining in one of the
Pennsylvania tunnels at New York. It shows clearly how the iron plates
are bolted together to make the rings of iron lining.]

[Illustration: The last, or closing, plate of each iron ring is called
the “key,” and is much shorter than the others. This photograph shows
the shield erector on one of the Pennsylvania tunnels picking up and
putting into place a key plate. This picture gives an idea of the mud
and dirt and wet in which the men who work in tunnels have to do their
work.]

[Illustration: Wherever possible, every space and crevice outside the
iron lining is filled with cement forced, in a liquid state, through
the iron lining by compressed air. This photograph shows the operation
of “grouting,” as it is called. The man at the left is in control of
the grouting. He has the hose, through which the grout is forced,
screwed to a pipe which passes through a hole made for the purpose in
the iron lining plates and called a “grout hole.” The two men in the
middle of the picture are attending to the “grouting machine” by which
the work is done. Water and cement are fed into the small boiler-like
tank, the tank closed and compressed air admitted thus blowing the
liquid cement through the hose and behind the iron lining. When no
more grout can be forced behind the iron lining all the space has been
filled. The man on the right is the engineers’ inspector taking note of
how much grouting is done, and seeing that the work is properly carried
out.]

[Illustration: This shows the process by which the iron lining is made
perfectly water-tight, so that, when the compressed air is taken off,
no water at all can get into the tunnel. Two operations are shown here.
One is called “grommetting the bolts,” the other is called “caulking
the joints.” The two men on the left, hanging on to the wrench, are
tightening up the bolts as tight as they can after having put on,
underneath the washers at the head and nut of each bolt, a ring of
spun yarn dipped in red lead and oil or tar or some such water-proof
material. A few of these “grommets” may be seen at the feet of the
third man from the left. The other four men are caulking the joints
between the iron plates by driving into the joints a mixture of sal
ammoniac and iron borings. This sets as hard as iron and if properly
done makes a perfectly water-tight joint.]

[Illustration: THE REMARKABLE ACCURACY OF ENGINEERING

Usually when crossing, with a tunnel, a wide river or estuary the
tunnel is started from each shore and the shields are pushed through
the ground until they meet somewhere about the middle of the river.
This shows two of the Pennsylvania tunnel shields which have met far
below the Hudson River. The white arrow shows where each shield ends.
The platform of one shield on which the man stands corresponds exactly
with the platform of the other shield. As may be imagined, it takes
very careful and skillful engineering and surveying work, both before
the work is begun and while it is being carried out, to enable tunnel
shields to meet like this. This part of the art of tunnelling would
take an article to itself.]

When the shield has been pushed across the entire length of the water
way which has to be tunnelled, and the whole of the iron tube or shell
is in place, a thick lining of concrete is placed inside the iron shell
to protect it and make the tunnel stronger. As an added safeguard
wherever the tunnel is in rock, gravel, strong clay or other ground
which is not so soft that it does not close tightly in on the outside
of the tube, liquid cement is forced by compressed air through holes
made in the iron plates for this purpose. This liquid cement enters
every pore or crevice in the surrounding ground and when it has set
hard it still further protects the iron with a coating of cement.
Pieces have been cut out of the iron lining of a tunnel built under the
river Thames at London, England, in 1869, which showed that the iron
at all places was as good as the day it was first put in forty years
before, and iron put in the lining of the Hudson River Tunnel about
1878 when removed after thirty years was in perfect condition.

[Illustration: SHIELD AT END OF JOURNEY

Sometimes, however, shields are not driven to meet one another, but end
their journey at some shaft or in some other tunnel previously built,
after having gone through thousands of feet of all kinds of ground,
from the hardest rock, which had to be blasted out foot by foot before
the shield could advance, through hard pan, gravel, boulders, piles,
rip-rap, made ground and mud so soft that it flows like melted butter.
Naturally, after an experience like this a shield does not look as
spick and span as when it started in life. This photograph shows one
of the shields of the Hudson and Manhattan Railroad in New York just
reaching the end of its journey, battered and bent but still in the
ring.]

[Illustration: This shows a piece of curved tunnel near Morton Street,
on the Hudson and Manhattan Railroad, and is given because of the clear
showing it gives of the iron lining. The track and floor are only the
temporary roads for use during construction.]

[Illustration: Sometimes it is necessary to make borings of the ground
below the tunnels. In some of these bore holes vast quantities of water
are found at a much higher pressure than the tunnel compressed air.
This picture shows a spouting bore hole in one of the Pennsylvania
tunnels during construction.]

[Illustration: The last thing to do before laying the track is to put
the concrete inside the iron lining. This picture shows this work going
on and the wooden forms or ribs for holding up the concrete while it is
setting.]

[Illustration: THE LAND END OF A GREAT TUNNEL UNDER THE HUDSON

This view is given to show how complicated an underground structure
may have to be made to take care of the requirements of traffic. This
view shows the three great reinforced concrete caissons sunk through
the earth at Jersey City in order to contain the switches and crossings
required to form the New Jersey connections of the uptown and downtown
tunnels of the Hudson and Manhattan Railroad.

These caissons were sunk under air pressure by excavating below them
just as though they were tunnels turned up on end. In sinking these
caissons the material passed through was water-logged made ground, and
the hulls of two sunken canal boats were encountered and had to be cut
into pieces small enough to be taken out through the locks.

The usual passenger rushing at high speed in the trains between Jersey
City and Newark and New York has little idea of the very complicated
structure necessary to allow of his doing so.

The information in this article was supplied by Jacobs & Davies, Inc.,
Consulting Engineers, 30 Church Street, New York, the Engineers for the
Pennsylvania Railroad, Hudson River Tunnels, the Hudson and Manhattan
Railroad, and many other tunnels in various parts of the world.

The illustrations were kindly supplied by the Pennsylvania Railroad and
the Hudson and Manhattan Railroad.]

~DANGERS OF TUNNEL BUILDING~

This account of tunnelling by shield and compressed air is very
short and gives no more than a bare statement of the principles and
chief methods of such work. Nothing has been said of the engineering
difficulties involved in the design of such work, nor of the delicate
surveying work necessary if one should hope to start two shields a
mile or two apart and have them meet as shown in Fig. 13 like two
great glass tumblers placed rim to rim after having travelled through
thousands of feet of every kind of ground. Nothing has been said of the
men who work on this most arduous form of subterranean navigation, how
they cheerfully face the dark and the water ever threatening above them
and the unseen but not less deadly ally, and yet foe, the compressed
air, with its dreaded result, the bends, or the men on the surface
who keep the air compressors running without pause or stop day in and
day out until the work is done so that their comrades below may work
in safety. Nothing has been said of the curious accidents that are
liable to occur as when the air pressure in the tunnel gets too high,
overbalances the water pressure and blows a hole through the river-bed
and forms a geyser in the river above. It gives no account of the
special difficulties which arise when special conditions are found;
for example, when the lower part of the tunnel is in rock and the
upper part is in soft material. In fact it is nothing more than a bare
outline but it hoped that some, who may not be clear in their minds as
to how tunnels are built, may learn some of the first principles of
this most romantic kind of work from this bald narrative.




Why Do My Teeth Chatter?


Your teeth chatter because when you are cold in a way that makes your
teeth chatter the little muscles which close the jaw act in a series of
quick little contractions which pull the jaw up, and then let it fall
by its own weight. This is repeated many times and, as the action is
quick, the chattering occurs. It is a peculiar thing that this occurs
in spite of the will or brain, when, as a matter of fact, these muscles
which operate the jaws are especially under the control of the brain.
The chattering is really a spasm caused by the cold, and all spasms act
independent of the will. Cold seems to act on the jaw muscles a good
deal like some poisons which cause spasms.




Where Did All the Water in the Oceans Come From?


No, it did not come from the rivers which empty themselves into the
oceans, because the oceans were there before the rivers existed. Part
of it comes from the rivers now, but only a little in comparison to all
the water there is in the ocean. I will try to tell you simply how all
the water got into the ocean.

There was a time when there was no water on the earth at all. That was
when the earth was red hot, just as it is to-day on the inside, and at
that time all the water we have to-day was up in the air in the form of
gases. Strange as it may seem to you, if you take two gases, one called
hydrogen and the other oxygen, and mix them the right way, they will
turn into water, and if you had the right kind of chemical apparatus
you could take water and turn it into these gases again. When, then,
the earth was still all red hot, all of our water was up in the air in
the form of these two gases. Then, later on, when the amount of heat on
the earth was just right to make these gases mix together, the water
came down out of the air in great quantities, and there was so much of
it that it completely covered the whole earth and no land was visible.
Later on, for various reasons, mountains were thrown up on the earth’s
surface by great earthquakes, and every time a mountain or a high place
was formed there had to be a hole or low place some place else, and the
water ran into these low places and stayed there, and that uncovered
more of the land, because there wasn’t enough water to fill all the
holes and cover the land too, and that is what makes our continents
and islands and all of the land we see. There is now about three times
as much earth covered with water as there is land. Of course, the sun
is always picking up water through what is called evaporation, which
means that it is taken into the air in the form of gases. Later it
comes down again in the form of rain and falls into the oceans or on
the land, where it sinks in, finally finding a stream or river, and
sooner or later gets back into the ocean again.




Why Don’t the Water in the Ocean Sink In?


This is due to the fact that there is a kind of substance at the
bottom of the ocean which the water cannot penetrate, in spite of the
tremendous pressure which the great body of deep water exerts. In all
places where the bottom of the ocean has a covering which water can
sink into it does so, but there are such a few places where this is
possible, by comparison, that the amount that gets out that way is not
noticeable. This water, if it can keep on going, will eventually reach
the inside of the earth, where it is red hot, and is turned into steam.




Where Does the Water in the Ocean Go at Low Tide?


To get to the answer of this you must know something about the tides.
The tide is caused by the pull of the moon on the waters in the ocean.
The moon revolves about the earth once each day and has the ability to
draw up the waters in the ocean toward it, as we have seen in our study
of the tides.

Now, when it is high tide in one place it is low tide in another. The
moon does not make more water, but only pulls it toward it from side to
side. When it is low tide where we are the water has simply moved as a
body toward the place where it is high tide.

The tides act a good deal like a see-saw, except that they move from
side to side instead of up and down. When one end of the see-saw goes
up the other end goes down, and when the “down” end comes up the other
end goes down. So the answer to your question really is that at low
tide the water which made it high tide a few hours before has gone to
some place where it is at that moment high tide.




Why Does the Ocean Look Blue at Times and at Other Times Green?


Sometimes when we look at the ocean from the pavilion or while on the
sand of our favorite bathing beach the water in the ocean looks very
beautifully blue, and on other days will look dark green from the same
point. Why is it? If you will stop to think that at night when there is
no moon or other light the water in the ocean looks black, I think you
will soon be on the right track to answer the question yourself.

When the sky is blue--the kind of blue we like to see in the sky when
we are at the beach--the water in the ocean is blue, because the sea
reflects the color of the sky, and when the sky is overcast and gray
the color reflected by the sea will be gray also.

But, say you, sometimes the water in the ocean is dark green, and yet
the sky is never green. Quite true, and I will try to tell you what
produces the green color. This happens sometimes where the water is
shallow, either near the shore or out further where there is a sandbar
or other shallow place. Sometimes at such points the sunlight strikes
the water at such an angle that the rays go clear to the bottom and are
reflected from that point--the bottom--to our eyes. In such a case the
light will be changed through a combination of the color of the bottom
at that point and the color of the sky itself at the time to make the
color green as it is reflected to our eyes from the bottom.




Why Does Water Run?


Water runs because it has not enough of anything in it to make it stick
together.

In school language we call this sticking-together-thing “cohesion.”
The principle of cohesion makes all the difference there is, so to
speak, between solids, liquids and gases. A brick, a stone, a stick
of wood, or a piece of iron and all other solid substances have a
certain amount of this property of cohesion, and the particles stick
together, enabling us to build buildings and other things which become
permanent structures. These solid substances are either naturally
cohesive or else man, as in the case of the brick, has brought together
certain things with little or no cohesion and made them stick together
permanently. In the case of the brick, he takes a quantity of clay,
which is cohesive only to a certain degree, bakes it in an oven and
it becomes hard enough--more cohesive--so that he can pile one on top
of the other and make a building. Then he puts sand, mixed with other
things--lime and water--between the bricks to hold the bricks together,
and makes a structure that will last. Two bricks have no natural
cohesion for each other and, therefore, they can only be held together
by something that has cohesion within itself and also for the bricks.
The lime, sand and water make mortar which is cohesive when properly
mixed, while in themselves neither lime nor sand have much cohesive
property, and water has none at all.

Liquids have little or no cohesion. Water has none, or very little.
Syrup has a good deal more, but will run over the edge of a piece of
bread and butter if you are not careful.

Gases have no cohesive properties at all and, therefore, fly all over
the place, through any opening they can find, either at the top of the
room or under the crack of the door. They are always trying to get to
some place else and will keep moving as long as not confined. Gases can
move in any direction.

Liquids, however, while they are inclined to be constantly on the move,
can only go in one direction--down hill, and they go down fast or slow
if there is a chance, in proportion to the amount of stick-together
properties they have. Liquids can never go up of their own accord,
excepting in the process of evaporation, and then only when changed
into gases. A lake of water will dry up completely by evaporation
unless fed by streams of water constantly flowing in, because
evaporation is constantly taking place wherever water is exposed to the
air.




What Makes the Water Boil?


What we call boiling in the water we see when water is put over a hot
fire long enough to make it boil, is the changing of the water from
what we generally regard it--a liquid--into gases. Water consists of
two gases--hydrogen and oxygen--in fact, two parts of hydrogen gas and
one part of oxygen gas when mixed will always make pure water. Now,
then, if liquid water is heated to a certain point or temperature it
turns into the two gases, oxygen and hydrogen, and comes to the top of
the water, which still remains in liquid form, in the form of a bubble
and explodes into the air--not a very loud explosion, but still an
explosion. The process of turning liquid water into gases is a gradual
one, and that is why the water does not all turn into one large bubble
at once and explode away. If you keep the fire going long enough, all
the water in the vessel will explode away into the air, a few bubbles
at a time. If you hold a cold plate over the vessel as the bubble
explodes you can catch some of these gases in the form of bubbles on
the under side of the plate, which are again liquid water. When the
water becomes hot enough it turns into bubbles and as bubbles rise
that is what makes the boiling you see. When the same gases then come
together again in a certain proportion under proper temperature they
turn into liquid water.




At What Point of Heat Does Water Boil?


The boiling point of water is the temperature at which it begins to
pass into the form of gases. This varies in different altitudes. At
the sea level the boiling point is at 212° Fahrenheit. On the top of
mountains, for instance, water would boil at a much lower temperature.
It would be possible to go high enough in a balloon so that the water
would fly from the pan in the form of gas without making the water hot.
Also, a mile below the level of the sea it would take many more degrees
of heat to make the water boil. It is said that high up in a balloon
you could not boil an egg hard in a pan of boiling water if you kept it
in the boiling water for an hour or more, whereas we know that an egg
will be hard-boiled if we keep it in boiling water down where we live
for more than five minutes.

The degree of heat at which water passes away into the form of gases
is regulated by the pressure of the air on the water and other things
about us. At the average level in the United States where people
live the pressure of the air on everything is fifteen pounds to the
square inch, and at this pressure water boils only after it reaches a
temperature of 212° Fahrenheit. As we go up the mountains the pressure
becomes less and less as we go up. At the top of Mount Blanc, which is
15,781 feet high, water boils at 185° Fahrenheit. If we took a balloon
from the top of the mountain we would come to a height where there was
no air pressure at all.




What Do We Mean by Fahrenheit?


The name Fahrenheit is used to distinguish the kind of scale most
commonly used on thermometers in Great Britain and the United States.
Gabriel Daniel Fahrenheit, a native of Dantzic, made the first
thermometer on which this scale was used, and it is named after him. In
this scale for thermometers the space between the freezing point and
the boiling point is divided into 180 degrees--the point for freezing
being marked 32 degrees and the boiling point 212 degrees.




Why Can’t We Swim as Easily in Fresh Water as in Salt Water?


Our bodies are heavier than fresh water, i. e., a bulk of fresh water
equal to the size of our body would weigh less than our body, so that
the first tendency is to sink to the bottom if we find ourselves in
fresh water. If man had not learned to swim that is what he would
always do, sink to the bottom; but having learned how to keep from
sinking, he is able to swim in fresh water. However, we find that an
amount of salt water equal to the bulk of a man in size is heavier than
an equal amount of fresh water, although such a bulk of ordinary salt
sea water will still weigh less than the man. A man will sink in salt
water also if he has not learned to swim or float, but he can keep up
with less effort in salt water, and also swim in it more easily. In
a nutshell, then, the answer to this question is that salt water is
heavier than fresh water. You can make salt water so full of salt that
it becomes heavier than a man. Great Salt Lake in Utah is so salty that
one cannot sink in it for this reason. You could drown yourself in it,
of course, by keeping your head under water, but whether in shallow
water or deep water you would not sink in Great Salt Lake.




Why Do We Say Some Water Is Hard and Other Water Soft?


What we call hard water contains certain salts which soft water does
not contain. This salt in hard water is lime or some other salts which
the water has picked up out of the ground as it passed through either
coming up or going down. On the other hand, we can guess after having
been told this much that if we can find any water that has not passed
through the ground, and, therefore, not had a chance to pick up any
salts, we will have soft water. From that point it is easy to guess,
then, that rain water must be soft water, and so it is. The water in
the cisterns, which is rain water, is soft water, and the kind we get
out of the wells is hard water.

We do not like to wash either our faces or our clothes in hard water,
especially when it is necessary to use soap, because when we use soap
with hard water the soap undergoes chemical change which prevents its
dissolving in the water. Therefore, you cannot easily do a good job
of washing in hard water. On the other hand it is easy to dissolve
the soap in pure rain water or soft water and that is the kind we,
therefore, prefer for washing.




How Does Water Put a Fire Out?


This is at first a puzzling question, because back in your mind is the
thought that since hydrogen and oxygen are necessary to make a fire
burn, it seems strange that water, which is composed of oxygen and
hydrogen, will also put it out.

A burning fire throws off heat, but if too much of the heat is taken
from the fire suddenly the temperature of the fire is sent down so far
below the point at which the oxygen of the air will combine with it
that the fire cannot burn. We speak commonly as though water thrown on
a fire drowns it. That is practically what happens. Scientifically what
happens is that the water thrown upon the fire absorbs so much of the
heat to itself that the temperature of the fire is reduced below the
point where oxygen will combine with the carbon in the burning material
and the fire goes out.

To answer the unasked part of your question at the same time I will
say that hydrogen and oxygen when combined as water will put the fire
out rather than make it burn, more because when these gases take the
form of water they are already once burned, and you know that anything,
substance or gas, which has already been burned cannot be burned again.
It required great heat to make oxygen and hydrogen combine and form
water, and it also takes great heat to separate them again. So they are
really burned once before they become water.




Where Does the Rain Go?


Eventually almost all of the rain that falls runs into the rivers
and lakes and later finds its way into the ocean, where it is again
taken up into the air by the sun’s rays. But many other things happen
to parts of the rain which do not find their way into the ocean. In
the paved street, of course, where the water cannot sink in, it flows
into the gutter and thence into the sewer and on down to the river or
wherever it is that the sewers are emptied. You see, it depends very
much on what the earth’s surface is covered with at the place where
the rain falls. When it strikes where there is vegetation a great deal
of it stays in the soil at a depth of comparatively few feet. If it is
soil where trees and other plants grow a great deal of it is sucked up
from the ground by this vegetation and given back into the air through
the leaves and flowers. Some of the rain keeps sinking on down into the
earth until it strikes some substance like rock or clay, through which
it cannot sink, and then it follows along this until it finds something
it can get through and collects in a pool and forms an underground
lake, and may cause a spring to flow. Then there are also worms and
other forms of animal life in the earth which use up some of the water.
But it all gets back into the air eventually to come down some time
again in the form of rain.




Why Does Rain Make the Air Fresh?


The main answer to this question must be that the rain in coming down
through the air drives the dust and other impurities which are in the
air before it, and so cleans the air and makes it absolutely clean.
In addition to this it is now stated that since very often rain is
produced by electrical changes in the air, and that these electrical
changes produce a gas called ozone, which has a delightfully fresh
smell, it is this ozone that makes us say the air has become fresh.

The air above our cities is almost constantly filled with smoke,
containing various poisonous gases, and these are driven away by the
falling rain.

Then, too, there is always a greater or less accumulation of dirt,
garbage and other things in the cities which give off offensive smells
constantly, but which we do not notice always because we become used to
them. When the rain comes down it washes the streets and destroys these
smells, and that makes the air fresh and delightful to take into the
lungs.

In the country the air is more nearly pure all the time, because the
things which spoil the air in the city are not present.




Is a Train Harder to Stop Than to Start?


The answer is yes. It is harder to stop a train than to start it, or
rather it takes more power. The speed of a train depends upon the
motive power. When a train is stopped and you wish to start it, you
must apply enough motive power to start it going. There must be enough
power to move the weight of the train and overcome the friction of the
wheels on the track. It is, of course, easier to move a thing that
weighs less than a heavier one. If you throw a ball ten feet into the
air, it will perhaps not sting your hand when you catch it on its
return; but, if you throw it one hundred feet into the air, it will
sting your hands when you catch it. Besides, it will come down faster
the last ten feet of the way than the ball which you threw only ten
feet into the air. This is because when movement is applied to anything
you add power to it. The ball which comes down from one hundred feet
in the air acquires more power in falling and it takes more power to
stop it. A train in motion has not only the power of the weight of the
train behind it, but also the additional weight which the movement of
the train has given it. Therefore, it takes more power to stop it than
to start it. To stop a train you must apply the same amount of power as
is in the moving train because the power to stop any moving thing must
always be at least as great as the power which is moving it.




What Makes the Knots In Boards?


We find knots in the boards which we notice in a lumber pile or in any
other place where boards happen to be, because the smaller limbs which
grow away from the larger limbs of trees grow from the inside as well
as the outside of the tree.

When you see a knot in a board it means that before the tree was cut
down and the log sawed up into boards, a limb was growing out from the
inside of the tree at the spot where the knot occurs.

You will also find that the wood in the knot is harder generally than
the rest of the board. This is because more strength is required at the
base of a limb and in the part of the limb which grew inside the tree
than in other parts, for the limb must be strong enough to support not
only the limb itself, but also the smaller limbs which grow out of it.




How Many Stars Are There?


Man may never know how many stars there are. The best we can do is
to figure on the number that can be seen with the largest telescopes
which have been invented, for, of course, you know there must be many
millions of them which to us are invisible. We have counted the stars
so far as we can see them; or, rather, so far as we can photograph
them. Astronomers have found that a photographic plate exposed to the
stars will show more of them than can be seen by the naked eye. This
is because the materials on a photographic plate are more sensitive
to the light of the stars than the human eye. By this method man has
been able in a way to count the stars he can see. It adds up to more
than a hundred million of them. Astronomers found this out by taking
photographs of the heavens at night, devoting one picture to each
section, until the entire heavens had been covered, and then counting
them.

[Illustration: WHERE PAINT COMES FROM

MAKING LEAD BUCKLES--THE FIRST STEP IN PAINT MAKING.]




The Story in a Can of Paint


Paint such as is most frequently used is the material used for painting
buildings, such as houses, barns, stores, and many others which we need
not mention here. This paint is used on these buildings mostly for two
very important reasons--one being to beautify the buildings, the other
being to protect them from the ravages of the weather, much in the same
way that your clothes protect you from the weather.

Paint such as we mention here may be regarded as the most simple
and useful form. You have no doubt frequently seen the painter-man
spreading paint on some building, or perchance, you have seen your
father doing it, and have noticed that paint is a fluid substance
looking something like cream, which is applied to the surface to be
painted with a suitable brush and is brushed out smoothly. After the
first coat is dry, other coats are put on in the same way until enough
paint has been put on to thoroughly hide the unevenness of the lumber
and making it of a uniform color.

This paint is made by simply mixing together dry powder, which is
usually called pigment, with a thin, yellowish liquid which is called
linseed oil. In the earlier days, the painter-man mixed this paint
himself whenever he desired to use it. In these more modern times, he
usually buys this paint already prepared.

Perhaps a little history of the preparation of the package of a can of
paint which he buys may be interesting to you.

Let us imagine that the can of paint is white. In this case, the
pigment which is used is a white powder and is made of either metallic
lead or metallic zinc. The preparation of this fine white powder is
very interesting and requires considerable time to perfect.

Let us consider the pigment known as white lead first. This is produced
by causing metallic lead, which is of a bluish-gray color and very
heavy, to change from its original form by a process which is known
as “corrosion.” This corrosion is brought about by first taking the
metallic lead, which at this stage exists in large pieces known as
“pigs.” These pigs of lead are melted in a furnace and then molded into
small, thin shapes which are buckles.

[Illustration: HOW WHITE LEAD IS MADE

FILLING THE STACK WITH LEAD BUCKLES.]

[Illustration: LEAD BEING TAKEN OUT OF THE STACKS.

The next step is to take an earthenware vessel, which resembles an
ordinary stone crock, and first pour into it a small quantity of acetic
acid, which is about the same as table vinegar. Then the crock or pot
is filled up with the lead buckles.

Where this white lead is made in a large way many thousands of these
pots are placed in a building, the sides of which are walled up tight,
the spaces between the crocks being filled in with tan bark. After
the floor has been covered with a layer of these crocks, the layer is
covered with boards, in order to provide a foundation for setting in
the next layer of crocks and tan bark. The layer of boards also serves
as a floor to keep the tan bark from falling into the open crocks on
the tier below. This procedure is followed with tier after tier until
the building is completely filled.

Corrosion of the metallic lead in the pots now begins, because the tan
bark generates some heat, becoming finally quite warm. This heat causes
the acetic acid or vinegar to throw off vapor or steam, which attacks
the metallic lead, causing it to decompose or corrode. This process
goes on for many weeks (sometimes as much as fifteen or sixteen weeks),
until those buckles of metallic lead have become a mass of white powder
and nearly all trace of the original metallic lead has disappeared.]

[Illustration: A LEAD BUCKLE AFTER CORROSION.]

[Illustration: A LEAD BUCKLE BEFORE CORROSION.]

[Illustration: HOW OXIDE OF ZINC IS OBTAINED

WASHING THE LEAD. SCREENS COVERED WITH CLOTH REMOVE ALL FOREIGN MATTER.

After these many weeks have passed, the pots containing the white
powder of carbonate of lead, as it is called, is taken out of the
building where corrosion took place, and the white deposit is put
through an elaborate system of refining, which is called “washing,”
and, in fact, is really washed in water, and is then dried in very
large copper pans. After being dried it is in the form of large white
cakes, resembling pieces of chalk. These cakes are then passed through
a mill, which grinds them to very fine powder, which is packed in
barrels ready to be shipped and used by the paint-maker.]

[Illustration: FURNACE WHERE THE SULPHUR IS ROASTED OUT OF THE ORE.

Now that we have followed through the process of making the white-lead
powder, or pigment, let us take a little time to study the preparation
of the other white powder, known to the paint trade as “oxide of zinc.”
This is prepared in a manner quite different from that of the white
lead.

First the ore which is mined from the earth containing the metallic
zinc is carefully selected by expert workmen and placed in a special
kind of furnace, being mixed with hard coal, such as we use in our
heating stoves.]

[Illustration: A ZINC SMELTER--THE MEN KEEP THEIR MOUTHS COVERED SO AS
NOT TO INHALE THE VAPOR, WHICH IS POISONOUS

The burning of the coal causes an intensely high temperature, sometimes
being several thousand degrees. This causes the zinc ore to be consumed
as it were or to pass into a form of vapor. This vapor is carried
through huge pipes which are several feet in diameter and extend for
a long distance. While these vapors are passing through these pipes
it becomes cooled. After becoming cooled it takes on the form of very
fine white powder, coming from the pipes in much the same way that
snow falls from the sky in the winter. This is collected and placed in
barrels, after which it is ready for the paint-maker without further
preparation.]

~WHERE LINSEED OIL COMES FROM~

Since we have followed the preparation of the two important white
pigments used in making our can of paint, it is now important that
we devote a little thought to the liquid which is to be used. This
is called “Linseed Oil.” Linseed oil is of a golden yellow color,
resembling the appearance of thin syrup which we sometimes have on the
table. This oil is taken from the seed of the flax plant. It might
better be called “Flaxseed Oil,” yet it is not commonly known by that
name, but is nearly always referred to as “Linseed Oil.” Flax is grown
in many parts of the world, the most important places being the United
States of America, Dominion of Canada, Ireland, India and the Argentine
Republic. In the United States, the seed is sown early in spring, much
the same as is done with other crops, and ripens and is harvested early
in the fall of the year. The harvesting and separation of the seed from
the plant or straw is done very much in the same way that other crops,
such as wheat and oats, are harvested. The seed is then taken to market
and is ready for the extraction of the oil, which is done by men who
are known as “oil crushers.”

[Illustration: PRESSING OIL OUT OF FLAXSEED.]

[Illustration: REMOVING OIL CAKE FROM PRESS.]

The oil is extracted from the seed by a very simple process. Usually
the seeds are heated by steaming them, after which they pass through
a mill, being ground to a coarse mass, which is then placed in very
powerful machines called “Hydraulic Oil Presses,” which squeeze the oil
from the seed, leaving the remainder in the form of large cakes which
are then ground to a mealy-like powder which is used as food for cattle
and is very much prized.

The oil which has been extracted by this process is put into large
tanks where it is clarified and is then ready for the paint-maker.
This oil is often referred to as “Vegetable Oil” and it has one very
peculiar and very important characteristic which makes it useful and
necessary for use in paint. This property is that of drying or becoming
solid, losing all tendency to stickiness after it has been spread out
thinly and exposed to the air for a short time.

[Illustration: WHERE LEAD IS GROUND IN OIL.]

[Illustration: WHERE PAINTS ARE MIXED.]

Now that we have given attention to the preparation of the most
important things used in the making of our can of paint, let us look a
little to the manner in which they are put together, and the result.

The oil is necessary in making paint in order to make it fluid, so that
the paint may be brushed on to the wood or other surface, and also so
that the pigment or powdered material which has been put into the paint
will have something to hold it to the surface. The oil or other liquid
which may be used is usually called “Binder” by the paint man because
it binds the pigment in the paint and to the surface on which it has
been spread or applied.

In a large paint factory, the two white pigments, lead and zinc, are
mixed with linseed oil in large machines known as “Mixers” into a
smooth paste which is then run through other machines called “Mills,”
where the paste is ground very fine into large tubes where the paint
is finished by mixing in enough more oil to make it of the proper
thickness or consistency for brushing. In this state it can be used,
but would not be entirely satisfactory because it would dry very
slowly. For that reason, the paint-maker adds in a small amount of what
is known as “Drier,” which causes the paint to dry much more rapidly
after it is spread out on any surface.

The paint-maker may also add in a small amount of thin liquid called
“Turpentine,” which also aids in the drying and the working of the
paint. Turpentine is a very thin liquid which looks like water, and it
is derived from the sap of one species of pine which grows abundantly
in the southern portion of the United States. The sap is taken from the
tree by tapping the tree or making an incision called a box, at certain
seasons. After the sap is collected it is put through a heating process
called “distilling,” which separates the water-white liquid, called
turpentine, leaving a large mass of heavy material which is commonly
known as “Rosin.” This turpentine is very useful to the paint-maker and
the painter. It is also used for many other purposes.

~WHAT MAKES THE DIFFERENT COLORS OF PAINT~

The paint which we have described is the most simple kind and is white.
There are many other kinds of paint used, being of many different
colors. All of these different kinds require different treatment and
preparation and would require many large books to explain even in a
brief way.

The white paint which we have described may be colored or tinted to
many different hues by adding suitable color pigments. These color
pigments are of many kinds and are derived from many different
sources. The vegetable kingdom is represented as well as the mineral
and animal kingdoms. The linseed oil which we have already mentioned,
is derived from the vegetable kingdom. This also applies to some few
of the pigments. A very important instance which we might mention
is a beautiful rich brown called “Vandyke Brown.” This is made from
decayed vegetation which is found in swampy districts. There are many
pigments derived from the mineral kingdom. White lead and zinc oxide
have already been described as useful. Among colored pigments coming
from this kingdom, we might mention yellow ochre, sienna, umber, cobalt
blue, and many others.

The animal kingdom supplies quite a number, one of which is a beautiful
red known as “Carmine.” This is taken from a small insect or fly which
is found in certain tropical climates. The production of carmine is
very expensive and the product is highly prized.

Another important development of the animal world is what is called
“Bone Black.” This is made by taking ordinary animal bones, putting
them into a suitable furnace and burning them, which really produces
bone charcoal, which is refined by powdering and washing, and finally
produces a beautiful black, such as used for painting fine coaches and
carriages.




Why Does a Dog Turn Round and Round Before He Lies Down?


Away back in the history of the animal kingdom, when the ancestors of
our domestic dog were wild, they slept in the woods or open. When they
were ready to lie down, they first had to trample the grass about them
flat to make a place to lie down. This became a habit and one of the
instincts of the animal which has been transmitted to the dogs of today
who keep it up. It is an inherited habit quite useless to the dogs of
to-day.




How Is Light Produced?


You already learned that a substance called ether is found in all
substances, filling the spaces between the molecules. When the
molecules are made to vibrate, the ether naturally also vibrates. As
soon as the vibrations become sufficiently rapid, they produce the
sensation of light. These vibrations also produce heat. In heated
bodies the molecules are always found to be in vibration, and a body
may become so hot that it gives off light. We notice this when iron
becomes red hot. Heat and light are found together in bodies in many
instances. In fact, most of the light we have comes from bodies which
are hot. The sun is so hot, that it is surrounded by the gases of many
substances that exist as solids on earth.

We have some bodies which produce light which is not accompanied by
much heat. The glow-worm, or firefly, seems to make light with little
or no heat; but we do not yet know how this is done. Almost all
sources of artificial light require that heat be produced before light
obtained. Only such vibrations of the ether which are sufficiently
rapid produce enough light to enable us to see. For this reason,
a piece of red hot iron, which is made luminous by heat and whose
particles vibrate less rapidly produce little light.




What Makes Rays of Light?


Whenever the ether is made to vibrate rapidly enough at any point,
the vibrations go in straight lines from the source of light in all
directions. A single line of vibrating particles in the ether, is known
as a ray. A number of rays, that issue from one point, are said to form
a pencil. A pencil of light may be produced by holding near a candle a
screen, with a hole in it. Sometimes rays of light are brought together
in a point, as may be done by means of a burning glass, and one of
these bundles of rays is known as a convergent pencil.

A bundle of rays that lie parallel to each other forms a beam. The rays
that come to us from the sun are practically parallel and are called
sunbeams.




Why Does a Nail Get Hot When I Hammer It?


When we are in the sunshine, or standing before a fire, we feel hot;
when we take snow or ice in our hands, they feel cold. The thing which
produces these sensations is called heat. When we feel heat, it is
because heat is absorbed by our bodies, and when we feel cold, it is
being thrown off by them.

To answer this question, we must see how heat may be produced. If we
draw a cord rapidly through our fingers, they feel hot, and if we rub
a coin briskly with a cloth or our hands, it becomes warm; if we take
a nail and hammer it on a hard substance, it becomes too warm for us
to hold. In these instances heat is produced by retarding or checking
the motion of a body. When we draw a cord through our fingers, it moves
less easily; we retard its motion by gripping it and this is what makes
the heat we feel. When we strike the nail with a hammer, the motion of
the hammer is checked by the nail, and the faster we pound with the
hammer, the hotter the nail becomes. From these experiments we learn
that whenever the motion of a substance is checked, or retarded, heat
is generated, and the substance made hot.

In explaining this method of producing heat, it was at one time thought
that all bodies contained a substance which produced the heat and that,
when rubbed or hammered, this substance was thrown off. About the
end of the 18th century, however, it was shown by Benjamin Thompson
(Count Rumford), that substances when rubbed give off heat. From this
we learned that heat is not a substance, because the quantity of
any substance, present in a body, cannot be limitless. If it were a
substance which produced the heat, the supply would sooner or later be
exhausted, and rubbing could no longer produce heat.

Heat produced by rubbing, or by striking substances together, is
caused as follows: If two substances are struck upon each other,
the whole of those substances are checked, but the molecules of the
substances are made to vibrate very rapidly, and these vibrations
produce the heat we feel.




How Do We Obtain Heat?


We get most of our heat from the sun. If the heat from the sun did
not reach us, no living thing would exist on the earth. No plants or
animals could live; the oceans and rivers would be solid ice.

Another important source of heat, is chemical action. Chemical action
is what causes fire. Even when it does not cause fire, it produces a
great deal of heat. When we breathe to keep our bodies warm, it is
a chemical action that occurs. Fire is the most important form of
chemical action, as a source of heat.




Why Does a Glow-Worm Glow?


A glow-worm is a kind of beetle which may be found in the yards and
hedges in the summer time. The name applies only to the female of
the species which is wingless and whose body resembles that of a
caterpillar somewhat and emits a shining green light from the end of
the abdomen. The male of this species has wings but does not show any
light as does the female and resembles an ordinary beetle. The male
flies about in the evenings looking for the female and she makes her
light glow in order that the male may find her. Glow-worms are found
mostly in England. There are, however, some members of the same species
of beetle common to the United States. We speak of them as fireflies
or lightning bugs. The female of these also is the only one carrying a
light, although unlike the glow-worm she has wings and can fly.




Why Do They Call It Pin Money?


This expression originally came from the allowance which a husband gave
his wife to purchase pins. At one time pins were dreadfully expensive
so that only wealthy people could afford them and they were saved
so carefully that in those days you could not have looked along the
pavement and found a pin which you happened to be in need of as you can
and often do today.

By a curious law the manufacturers of pins were only allowed to sell
them on January 1st and 2nd each year and so when those days came
around the women whose husbands could afford it, secured pin money from
them and went out and got their pins.

Pins have become so very cheap in these days that we are rather
careless with them, but the expression has continued to live although
today when used, it means any allowance of money which a husband gives
a wife for her personal expenses.

Pins were known and used as long ago as 1347 A. D. They were introduced
into England in 1540. In 1824 an American named Might invented a
machine for making pins which enabled them to be manufactured cheaply.
About 1,500 tons of iron and brass are made into pins every year in the
United States.




Why Do People Shake Hands With the Right Hand?


In the days of very long ago when all men were prepared to fight at any
and all times because one could not know whether another approaching
was a friend or an enemy, all men went armed. This was before the day
of guns when the sword was the great weapon of defense.

Upon occasion when one man approached another, each had to decide
whether the other came on a peaceful mission or not.

People in those days were mostly right handed as they are now and when
fighting carried their swords in their right hands.

If, then, a man wished to speak with a stranger or, as might easily
be necessary, to one who may even be known to be unfriendly, he put
out his right hand upon approaching to show that he had no deadly or
dangerous weapon in it. The other man could see this and knew from the
extended open hand that no harm was intended and that the approach was
peaceful. If, then, he was willing to meet the other, he also extended
his right arm with the hand open to show him who was approaching that
his fighting hand was empty also; and when they met each would grasp
the hand of the other so that neither one could change his mind and
assume a fighting attitude without the other having an equal warning.




How Did the Custom of Clinking Glasses When Drinking Originate?


In the days of the Roman gladiators, before a duel with swords, it
became the custom of each of the participants to drink a glass of wine
before fighting. Just before the fighting commenced two glasses of wine
were brought and the gladiators drank. These two glasses of wine were
provided by the friends of either one or the other of the gladiators.
To guard against treachery, through some over zealous friend of the
fighters furnishing poisoned wine was necessary. So before drinking and
to show there was no treachery, the gladiators came close together and
poured wine from one glass into the other back and forth until the wine
in the glasses was thoroughly mixed. If the wine in one glass then had
been poisoned, the poisoned wine would thus be in both glasses, and if
there had been any treachery, both gladiators would be poisoned if they
drank. The wine was poured from one glass to the other to show that
there was no treachery.

This custom continued in use for a long time until the idea of
drinking before a fight was abandoned. The custom, however, of showing
friendliness in this way while drinking continued for a long time.
Later it became a mere custom, however, to show a friendly spirit
toward the one who was drinking with you, and when the danger of
poisoned wine was past, the actual act of pouring the wine from one
glass to another was changed to merely touching the glasses together.
Thus today we have the friendly custom of touching glasses together
long after the necessity of guarding against treachery while drinking
has passed.




Why Cannot Fishes Live In the Air?


It is a curious thing isn’t it that if a boy falls into the water, he
will drown if he cannot swim or someone does not help him out, and that
if a fish falls out of the water onto the land, he will drown also,
even though he knows how to swim, better than anything else he does. A
boy cannot secure the air which he needs to live on if he is under the
water, because there is not enough air for him there and a fish cannot
secure enough air for him to live on when he is on land where the air
is plentiful, because, the boy takes his air from the air itself and
the fish gets his air out of the water.

To live by breathing the air we find on or above the land, it is
necessary to have lungs and fishes do not have lungs. In the case of
the boy under the water he would have to have gills to enable him to
make use of the air which is in the water to live by and he has no
gills.

A fish can only live a little while out of the water, but even so he
can live longer out of the water than a boy can under the water.

Lest you read sometime of the flying fish and think they must be able
to live out of the water, I will tell you before you ask the question
that the flying fish never stays out of the water for more than a few
seconds at a time. His flying leaps amount to little more than long
leaps from wave to wave. He swims along very fast in the water, coming
right up to the surface and out into the air and the speed at which he
has been swimming regulates the distance he will go when he shoots into
the air, as he has no means of propelling himself through the air, but
only into it. He has, however, wing-like fins, which he spreads out
when in the air and which enables him to glide through the air and thus
remain in the air longer.




What Makes a Fish Move in Swimming?


This is a puzzling question, I am sure. Of course, you at once cause
several other questions as soon as you ask this one such as the
following: Does the water in front of him move out of the way and then
close in behind him? If so, where does it go in the meantime? Does the
fish move the water forward or up or down or what does he do?

The answer is, of course, in the movements of the fish’s tail. The fish
in swimming is surrounded with water, top, bottom and all sides of him.
The pressure of the water on the fish is the same at all points so that
any motion made by him would have a tendency to make him move. As a
matter of fact the tail in moving from side to side creates a current
in the water from the head to the tail, or rather would produce an
actual current if the fish remained perfectly still. Instead of making
an actual current of water, the body of the fish is moved forward.

As to whether the water ahead of him opens up first and then the water
behind him is a more difficult question to answer. To the appearance it
would seem as if the water moved at both ends and sides at once, but
according to scientific theory, the water at the head of the fish is
displaced first.




Why Are Birds’ Eggs of Different Colors?


This is a wise provision of nature to help the mother birds hide her
eggs away from the eyes of her enemies. In the animal kingdom every
kind of life is the natural prey of some other kind of animal. A bird
will have enemies which try to catch her as food. A bird cannot fight
back, so must fly away when danger threatens, in order to save her
life. This means that she must leave the eggs in the nest for the
time being. At certain times she must also leave her nest and search
for food for herself. In order that the eggs so left alone may have a
better chance of not being discovered, nature has arranged matters so
that the eggs take the color very much of the surroundings in which
they are laid. Eggs of some birds are spotted or look like pebbles,
because the mother bird lays them in the sand. Some of them are green,
almost the color of the materials from which the bird builds the nest,
and so the colors have a real, and to the birds, a valuable purpose.




Why Does a Hen Cackle After Laying an Egg?


The hen cackles because she is glad. She is glad because she has just
accomplished something, which she was put on earth to do. If you study
the life on the earth carefully with this in mind, you will discover
that all kinds of life give expression in some form of gladness, when
they have performed the things they are on earth for. It’s the hen’s
way of expressing herself and letting the chicken world know. The dog
wags his tail when he is pleased; boys and girls jump up and down when
they are pleased, whether they have been doing anything commendable or
not. No doubt also the actual laying of the egg causes some discomfort
to the hen and the corresponding feeling of gladness would come
naturally after the discomfort disappeared.




Why Will Water Run Off a Duck’s Back?


The reason that water runs of a duck’s back, is that the feathers of
ducks are oily and, as water and oil will not mix, the water runs off
instead of soaking in. The feathers on a duck are so thick on the body
of the duck, top and bottom, that even if it were not for the oil which
is on the feathers the water would have some difficulty in soaking
through the feathers. But the main reason why the feathers on a duck’s
back cause water striking them to run off is that the duck has an oil
gland which is constantly producing grease or oil and which the duck
uses in giving his feathers a thin coating of oil to make them slick
with oil and when any water strikes the duck it runs off. Other birds
which live in the water a great deal have this oil gland for the same
reason.




THE STORY IN A STEEL RAIL


[Illustration: A Blast Furnace.

Molten iron is brought from the blast furnaces to the open-hearth
furnaces, and dumped into a receptacle called a mixer, the capacity of
which ranges from 400 tons to 1000 tons, depending upon the number of
furnaces to be served.]

[Illustration: One-thousand-ton Mixer.]

  Pictures in this story by courtesy of Bethlehem Steel Co.

[Illustration: INSIDE OF OPEN HEARTH FURNACE

Charging Side of an Open-hearth Furnace.

An open-hearth furnace consists of a long, shallow hearth, suitably
enclosed in fire-brick, and bound together with steel binding. The
furnace is heated by burning gas and air, which have previously been
preheated, so that a temperature is obtained in the furnace ranging
from 2900 to 3050 degrees Fahrenheit.]

[Illustration: Pouring Side of an Open-Hearth Furnace.

The open-hearth process consists of the purification of iron by
oxidizing out the impurities and burning out the carbon of the iron
until a tough and ductile steel is produced, which can be made of any
desired composition by the addition of the necessary quantities of
alloys just previous to tapping and pouring. The impurities in the iron
are oxidized by the slag lying on top of the metal, and the burning
out of the carbon, which is a very slow operation, is hastened by the
addition of iron ore, the oxygen of which combines with the carbon of
the iron and passes off is a gas going up the stack.

When an open-hearth furnace is ready for a charge, a variable amount
of scrap, say 30 per cent of the total weight of material used for
the heat, is charged into the furnace. With this scrap is charged
sufficient lime or limestone to make the slag, as well as some iron ore
to assist in reducing the carbon of the iron. In about two or three
hours the required amount of molten iron is brought from the mixer in
ladles, and poured into the furnace on top of the scrap, lime and ore.]


[Illustration: MOLTEN STEEL BEING POURED LIKE WATER

Molten Steel Being Poured Into Ladle.

When the scrap has all been melted, a test is taken to determine the
amount of carbon remaining in the bath. Iron ore is added from time
to time until the carbon in the bath has been reduced to the desired
point, and the metal is sufficiently hot to pour. At this point
“recarburizers” (consisting of Ferro-Manganese, Ferro-Silicon, and
pig-iron, or coal) are added to get the required composition. The tap
hole at the back of the furnace is opened, and the steel is allowed to
run out into a ladle, the slag coming last and forming a blanket over
the steel in the ladle.]

[Illustration: Crane Carrying Ingot and Soaking Pit Furnaces.

The ladle is picked up by an electric crane and carried over cast-iron
moulds, which are set on cars, the steel being poured into the moulds,
resulting in steel ingots. A sufficient amount of time is allowed for
the steel to become chilled or set, when the cars are pushed under an
electric stripper, where the moulds are removed from the ingots. After
the ingots leave the stripper they are taken to the scales and weighed,
and after weighing are put into the soaking pits. The pits get their
name from the part they play in the heating of the steel for rolling.
When the steel ingot is stripped the outside of the ingot is cool
enough to hold the inside, which is still in a liquid state, and the
steel is put into the soaking pits to allow the inside to settle into a
solid mass, after which the ingot is reheated for rolling. The length
of time in the soaking pits depends upon the size of the ingot, as the
larger the ingot, the greater length of time is required to set.

When the steel is ready for rolling it is taken from the pits by
overhead electric cranes, and placed into a dump buggy at the end of a
roller line, which leads to the blooming mill. The dump buggy derives
its name from the fact that when the ingot is placed into same in
an upright position, the buggy, in order to place the ingot into a
horizontal position on the roller line, dumps over, in the same way as
if one were to rock too far forward in a rocking-chair, the dump buggy
operating on the same principle.]

[Illustration: GETTING READY TO MAKE A RAIL

Blooming Mill and Engine.

The ingot travels down the movable-roller line to the blooming-mill
rolls, which roll it down from a piece 19 inches by 23 inches to what
is known as an 8 inch by 8 inch bloom, which is the size usually used
in the manufacture of rails. The blooming mill derives its name from
the fact that after an ingot is rolled in same it is no longer called
an ingot, but a bloom.

After leaving the blooming mill the bloom travels along another roller
line to the shears, where it is cut into two or three pieces, the
number of pieces depending on the size of the rail which is to be
rolled. The blooms are then lifted over the roller line at the shears
by a transfer crane, and placed on a traveling roller line which
connects with the rear of the reheating furnace. This furnace is about
35 feet long, and is so constructed that when the bloom is pushed in
at the rear of the furnace, another bloom drops from the front or
discharge end of the furnace.]

[Illustration: THE INGOT BECOMES A RAIL

The Ingot Becomes a Rail.

The bloom dropping out, being sufficiently hot to roll into rails,
travels along another roller line to the roughing or first set of
rolls. Here the bloom is given five passes in the rolls, and is then
transferred to the strand or second set of rolls, where it receives
five additional passes; after this operation it is transferred to
the finishing or third set of rolls, in which it is given one pass.
The bloom has now been converted into a rail, and the rail travels
on another roller line to the hot saw, where it is cut into 33-foot
lengths, this being the standard length in this country for all rails.
The rails when hot are cut by the hot saw to lengths of about 33 feet
6¹⁄₂ inches, the allowance of inches being made for shrinkage in
cooling. It is difficult to believe that steel shrinks to this extent,
but this is a fact, and while the rails are cooling on the hotbeds
they have the appearance of being animated, as they move first one way
and then the other. After the rails are on the hotbed a sufficient
length of time to cool, they are taken from the hotbed and placed
on a traveling roller line, which takes them to an endless chain
conveyor. The statement that rails are put on hotbeds for cooling seems
paradoxical, but the hotbeds are so called because the rails are placed
on them while hot, and are left there until they have cooled.

The endless-chain conveyor places the rails on another bed, from
which they are picked up by an electric crane and distributed to the
straightening presses, where all burrs (which have been caused by the
hot-sawing operation) are removed before the rails are straightened.
After straightening they are transferred to drill presses, where they
have holes drilled into them for the accommodation of the splice bar,
after which they are placed on the loading docks.]

[Illustration: After being carefully examined by the railroad
company’s inspectors they are picked up from the loading docks by
electric magnets attached to a crane, and are placed in cars ready for
shipment.]




Who Made the First Felt Hat?


The felt hat is as old as Homer. The Greeks made them in skull-caps,
conical, truncated, narrow- or broad-brimmed. The Phrygian bonnet was
an elevated cap without a brim, the apex turned over in front. It is
known as the “cap of liberty.” An ancient figure of Liberty in the
times of Antonius Livius, A.D. 115, holds the cap in the right hand.
The Persians wore soft caps; plumed hats were the headdress of the
Syrian corps of Xerxes; the broad-brim was worn by the Macedonian
kings. Castor means a beaver. The Armenian captive wore a plug hat.
The merchants of the fourteenth century wore a Flanders beaver.
Charles VII, in 1469, wore a felt hat lined with red, and plumed.
The English men and women in 1510 wore close woolen or knitted caps;
two centuries ago hats were worn in the house. Pepys, in his diary,
wrote: “September, 1664, got a severe cold because I took off my hat at
dinner”; and again, in January, 1665, he got another cold by sitting
too long with his head bare, to allow his wife’s maid to comb his hair
and wash his ears; and Lord Clarendon, in his essay, speaking of the
decay of respect due the aged, says “that in his younger days he never
kept his hat on before those older than himself, except at dinner.”
In the thirteenth century Pope Innocent IV allowed the cardinals the
use of the scarlet cloth hat. The hats now in use are the cloth hat,
leather hat, paper hat, silk hat, opera hat, spring-brim hat, and straw
hat.




What Is the Hottest Spot on Earth?


The hottest regions on earth is said to be along the Persian Gulf,
where little or no rain falls. At Bahrein the arid shore has no fresh
water, yet a comparatively numerous population contrive to live there,
thanks to the copious springs which break forth from the bottom of the
sea. The fresh water is got by diving. The diver, sitting in his boat,
winds a great goat-skin bag around his left arm, the hand grasping
its mouth; then he takes in his right hand a heavy stone, to which is
attached a strong line, and thus equipped he plunges in, and quickly
reaches the bottom. Instantly opening the bag over the strong jet of
fresh water, he springs up the ascending current, at the same time
closing the bag, and is helped aboard. The stone is then hauled up, and
the diver, after taking breath, plunges in again. The source of the
copious submarine springs is thought to be in the green hills of Osman,
some 500 or 600 miles distant.




Where Do We Get Ivory?


Ivory is a hard substance, not unlike bone, of which the teeth of
most mammals chiefly consist, the dentine or tooth-substance which in
transverse sections shows lines of different color running in circular
arcs. It is used extensively for industrial purposes and is derived
from the elephant, walrus, hippopotamus, narwhal, and some other
animals. The ivory of the tusks of the African elephant is held in the
highest estimation by manufacturers; the tusks vary in size, ranging
from a few ounces in weight to 170 pounds. Holtzapffel states that
he saw fossil tusks on the banks of rivers of Northern Siberia which
weighed 186 pounds each. Ivory is simply tooth-substance of exceptional
hardness, toughness, and elasticity, due to the firmness and regularity
of the dentinal tubules which radiate from the axial pulp-cavity to the
periphery of the tooth.




How Did Trial by Jury Originate?


~WHY JURIES HAVE TWELVE MEN~

A jury consists of a certain number of men selected according to law
and sworn to inquire into and determine facts concerning a cause or
an accusation submitted to them, and to declare the truth according
to the evidence. The custom of trying accused persons before a jury,
as practised in this country and England, is the natural outgrowth of
rudimentary forms of trial in vogue among our Anglo-Saxon ancestors.
The present system of trial by jury is the result of a gradual growth
under the English Common Law. There is no special reason why twelve is
the usual number chosen for a complete jury except the necessity for
limiting the number. In a grand jury the number according to law must
not be less than twelve nor more than twenty-three, and twelve votes
are necessary to find an indictment. The ancient Romans also had a form
of trial before a presiding judge and a body of judices. The right of
trial by jury is guaranteed by the United States Constitution in all
criminal cases, and in civil cases where the amount in dispute exceeds
$20. A petit or trial jury consists of twelve men, selected by lot
from among the citizens residing within the jurisdiction of the court.
Their duty is to determine questions of fact in accordance with the
weight of testimony presented and report their finding to the presiding
judge. An impartial jury is assured by drawing by lot and then giving
the accused, in a criminal case, the right to dismiss a certain number
without reason and certain others for good cause. Each of the jurymen
must meet certain legal requirements as to capacity in general and
fitness for the particular case upon which he is to sit, and must take
an oath to decide without prejudice and according to the testimony.
A coroner’s jury or jury of inquest is usually composed of from six
to fifteen persons, summoned to inquire into the cause of sudden or
unexplained deaths.




Can Animals Foretell the Weather?


Certain movements on the part of the animal creation before a change of
weather appear to indicate a reasoning faculty. Such seems to be the
case with the common garden spider, which, on the approach of rainy or
windy weather, will be found to shorten and strengthen the guys of his
web, lengthening the same when the storm is over. There is a popular
superstition that it is unlucky for an angler to meet a single magpie,
but two of the birds together are a good omen. The reason is that the
birds foretell the coming of cold or stormy weather, and at such times,
instead of searching for food for their young in pairs, one will always
remain on the nest. Sea-gulls predict storms by assembling on the land,
as they know that the rain will bring earthworms and larvæ to the
surface. This, however, is merely a search for food, and is due to the
same instinct which teaches the swallow to fly high in fine weather,
and skim along the ground when foul is coming. They simply follow
the flies and gnats, which remain in the warm strata of the air. The
different tribes of wading birds always migrate before rain, likewise
to hunt for food. Many birds foretell rain by warning cries and uneasy
actions, and swine will carry hay and straw to hiding-places, oxen will
lick themselves the wrong way of the hair, sheep will bleat and skip
about, hogs turned out in the woods will come grunting and squealing,
colts will rub their backs against the ground, crows will gather in
crowds, crickets will sing more loudly, flies come into the house,
frogs croak and change color to a dingier hue, dogs eat grass, and
rooks soar like hawks. It is probable that many of these actions are
due to actual uneasiness, similar to that which all who are troubled
with corns or rheumatism experience before a storm, and are caused
both by the variation in barometric pressure and the changes in the
electrical condition of the atmosphere.




Nearest Approach Ever Made to Perpetual Motion in Mechanics.


An inventor has patented a double electric battery which seems to
come exceedingly near to perpetual motion. Instead of using the zinc
battery, he professes to have hit upon a solution which makes a battery
seven times as powerful as the zinc battery, with absolutely no waste
of material. The power of the battery grows gradually less in a few
hours of use, but returns to its original unit when allowed to rest a
few hours. He has two batteries so arranged that the power is shifted
from one to the other every three hours. A little machine has been
running for some years in the patent office at New York. Certain parts
of the mechanism are constructed of different expansive capacities, and
the machine is worked by the expansion and contraction of these under
the usual variations of temperature. In the Bodleian Library at Oxford
there is an apparatus which has chimed two little bells continuously
for forty years, by the energy of an apparently inexhaustible
“dry-pile” of very low electrical energy. A church clock in Brussels is
wound up by atmospheric expansion induced by the heat of the sun. As
long as the sun shines this clock will go till its works wear out. Mr.
D. L. Goff, a wealthy American, has in his hall an old-fashioned clock,
which, so long as the house is occupied, never runs down. Whenever the
front door is opened or closed, the winding arrangements of the clock,
which are connected with the door by a rod with gearing attachments,
are given a turn, so that the persons leaving and entering the house
keep the clock constantly wound up.




Do Plants Breathe?


Plants, like animals, breathe the air; plants breathe through their
leaves and stems just as animals do by means of their respiratory
organs. When a young plant is analyzed it is found to consist chiefly
of water, which is all removed from the soil; there is about 75 per
cent or more of this fluid present, and the rest is solid material.
Of this latter by far the most abundant constituent is carbon, almost
every atom of which is removed from the atmosphere by the vital
action of minute bodies contained in the green leaves. The carbon is
taken into the plant as carbonic acid gas. Plants also absorb oxygen,
hydrogen, and nitrogen from the atmosphere in different quantities
through their leaves, and also by means of their roots. These new
products stored are in turn used in building up the different organs
of the plant. Plants give off used-up moisture through their leaves,
just as animals perspire through the pores of their skins. Calculations
have been made as to the amount of water thus perspired by plants. The
sunflower, only 3¹⁄₂ ft. high, with 5,616 square inches of surface
exposed to the air, gives off as much moisture as a man.




What Depth of Snow Is Equivalent to an Inch of Rain?


Newly fallen snow having a depth of about 11¹⁄₃ inches is equivalent to
one inch of rain. A cubic foot of newly fallen snow weighs 5¹⁄₂ pounds
and a cubic foot of fresh or rain water weighs 62¹⁄₂ pounds or 1,000
ounces. An inch of rain means a gallon of water spread over every two
square feet, or about a hundred tons to every acre. The density of
snow naturally varies a good deal according to the speed with which
it falls. Temperature, also, has much to do with its bulk. In cold,
crisp weather, when the thermometer registers several degrees of frost,
snow comes down light and dry; but in moist, cold weather, when the
temperature is only just below thirty-two degrees, the snow falls in
large, partially thawed flakes, and occupies much less space where it
falls than that which reaches the earth during the prevalence of a
greater degree of cold.




How Are the Stars Counted?


Stars are counted by means of the telescope and photography. The
Astronomer-Royal for Ireland, Sir Robert S. Ball, in one of his
lectures mentioned a photograph which had been obtained by Mr. Isaac
Roberts representing a small part of the constellation of the Swan.
The picture is about as large as the page of a copy-book, and it
is so crowded with stars that it would puzzle most people to count
them; but they have been counted by a patient person, and the number
is about 16,000. Many of these stars are too faint ever to be seen
in the greatest of telescopes yet erected. Attempts are now being
made to obtain a number of similar photographs which shall cover
the whole extent of the heavens. The task is indeed an immense one.
Assuming the plates used to be the same size as that above mentioned,
it would require at least 10,000 of them to represent the entire
sky. The counting of stars by the telescope was first reduced to a
system by the Herschels, who introduced “star-gauges,” which were
simply a calculation by averages. A telescope of 18 in. aperture, 20
ft. focus, and a magnifying power of 180, giving a field of view 15
in. in diameter, was used for the purpose. The process consisted in
directing this instrument to a part of the sky and counting the stars
in the field. This, repeated hundreds of times, gave a fair idea of the
average number of stars in a circle of 15 in. diameter in all parts of
the sky. From this as a basis it is possible to reckon the number of
stars in any known area.




How Is the Volume of Sound Measured?


Sound arises from vibrations giving a wave-like motion to the
surrounding atmosphere, the wave gradually enlarging as it leaves the
source of disturbance, while at the same time the motion of the air
particles becomes less and less. The simplest method of determining the
number of vibrations of a sound is by means of Savart’s apparatus. This
consists of two wheels--a toothed or cog-wheel and a driving-wheel.
They are so adjusted that the cog-wheel is made to revolve with great
rapidity, its teeth hitting upon a card fixed near it. The number of
revolutions is indicated by a counter attached to the axis of the
cog-wheel. Suppose that sound is traveling in the air at the rate
of 1,000 ft. per second, and that Savart’s wheel is giving a sound
produced by 200 taps on the card per second, it follows that in 1,000
ft. there will be 200 waves or vibrations, and if there be 200 waves in
1,000 ft. each wave or vibration must be 5 ft. in length. The velocity
of sound through air varies with the temperature of the latter, but is
usually reckoned at 1,130 ft. per second.




At What Rate Does Thought Travel?


Thought travels 111 feet per second, or about a mile and a quarter per
minute. Elaborate experiments have been made by Professors Heimholtz,
Hersch, and Donders, to ascertain the facts on this question, the
result of which was that they found the process of thought varied in
rapidity in different individuals, children and old persons thinking
more slowly than people of middle age, and ignorant people more slowly
than the educated. It takes about two-fifths of a second to call
to mind the country in which a well-known town is situated, or the
language in which a familiar author wrote. We can think of the name
of the next month in half the time we need to think of the name of
the last month. It takes on the average one-third of a second to add
numbers containing one digit and half a second to multiply them. Those
used to reckoning can add two to three in less time than others; those
familiar with literature can remember more quickly than others that
Shakespeare wrote “Hamlet.” It takes longer to mention a month when a
season has been given than to say to what season a month belongs. The
time taken up in choosing a motion, the “will time,” can be measured as
well as the time taken up in perceiving. If it is not known which of
two colored lights is to be presented, and you offer to lift your right
hand if it be red and your left if it be blue, about one-thirteenth of
a second is necessary to initiate the correct motion.




What Is the Largest Tree In the World?


In San Francisco, encircled by a circus tent of ample dimensions, is a
section of the largest tree in the world--exceeding the diameter of the
famous tree of Calaveras by five feet. This monster of the vegetable
kingdom was discovered in 1874, on Tule River, Tulare County, about
seventy-five miles from Visalia. At some remote period its top had
been broken off by the elements, or some unknown forces, yet when it
was discovered it had an elevation of 240 feet. The trunk of the tree
was 111 feet in circumference, with a diameter of 35 feet 4 inches.
The section on exhibition is hollowed out, leaving about a foot of
bark and several inches of the wood. The interior is 100 feet in
circumference and 30 feet in diameter, and it has a seating capacity
of about 200. It was cut off from the tree about twelve feet above the
base, and required the labor of four men for nine days to chop it down.
In the center of the tree, and extending through its whole length,
was a rotten core about two feet in diameter, partially filled with a
soggy, decayed vegetation that had fallen into it from the top. In the
center of this cavity was found the trunk of a little tree of the same
species, having perfect bark on it, and showing regular growth. It was
of uniform diameter, an inch and a half all the way; and when the tree
fell and split open, this curious stem was traced for nearly 100 feet.
The rings in this monarch of the forest show its age to have been 4,840
years.




Where Did the Term Yankees Originate?


This is a word said to be a corruption of Yengees, the Indian
pronunciation of English, or of the French “Anglais,” when referring
to the English Colonists. It was first applied to the New Englanders
by the British soldiers as a term of reproach, later by the English to
Americans generally, and still later to the people of the North by the
Southerners.




How Far Does the Air Extend?


It is, perhaps, generally known that enveloping the earth is a layer
of air fifty or more miles in thickness. Just how thick this layer is
we do not know, but we do know that it extends many miles from the
earth. You may assure yourselves of this in a very simple manner by
watching the shooting stars that may be seen on any clear night. These
are nothing but masses of rocks that give off light only when they
have been made red-hot by friction with the air in their rapid flight.
The fact that we often see these stars while they are still many miles
from the earth proves to us that the air through which they are passing
extends to that height.




What Makes Us Feel Hungry?


Hunger is a peculiar craving which we are accustomed to say comes
from the stomach. It is the business of the stomach to change such
food as we take into it in such a way that the rest of the organs of
the body which we have for the purpose can make blood out of it. When
you feel the sensation of hunger, it means that the blood-producing
system is calling on the stomach to furnish more blood-making material.
The stomach prepares the food for blood production by mixing with it
certain juices which the stomach is able to supply. As soon as the
stomach is then called upon to supply more blood-making material, it
goes to work on what is in the stomach and begins mixing things. If,
however, there is nothing in the stomach, the craving which we call
hunger is produced. It is, therefore, then not altogether the stomach
which makes us hungry, but the parts of our body which actually turn
the food into blood after the stomach has prepared it.

To prove this it is only necessary to say that the sensation of hunger
will stop if food which is easily absorbed and, therefore, does not
need the preparation which the stomach generally gives, is introduced
into the system through other parts of the body, as, for instance, by
injecting it into the large intestine, which is a part of the body, the
food passes through after it leaves the stomach ordinarily.




What Makes Us Thirsty?


Thirst is a sensation of dryness and heat which is generally
communicated to us through the tongue and throat. The sensation of
thirst can be artificially produced by passing a current of air
over the membranes which cover the tongue and throat, but thirst is
naturally due to a shortage of water in the body. The human body
requires a great deal of water to keep it in condition, and when the
supply becomes low a warning is given to us by making the membranes of
the tongue and throat dry.

In connection with thirst, however, as in the case of hunger, where
the warning is given by the stomach, thirst will be appeased by the
introduction of water, either into the blood, the stomach or the large
intestine, without having touched either the tongue or throat, which
proves that it is not our tongue or throat that is thirsty, but the
body itself.




What Is Pain and Why Does It Hurt?


Pain is the result of an injury to some part of our bodies, or a
disturbed condition--a change from the normal condition. Pain is caused
by nerves in the body. The network of nerves coming in big nerves from
the back bone or spinal chord branches out in all directions, and near
the surface of the skin they spread out like the tiny twigs of a tree,
covering every point of the body. Some parts of our bodies are more
sensitive than others. That is because the nerves are then nearer the
surface or else there are more nerves in that part. The heel is perhaps
the least sensitive part of the body, as the nerves do not lie so near
the surface there.

Pain is not a thing which you can make a picture of or describe in
words. Pain is a sensation of the brain caused by a disturbance of
conditions in some part of the body. If you cut your finger, you cut
certain veins or arteries and also the tiny nerves in the finger.
The nerves immediately let the brain know that they are injured, and
the brain sets to work to have the damage repaired. But there is a
congestion right where the cut is. The veins being cut, the blood which
would ordinarily flow through them back to the heart, pours out into
the cut and the inside of your finger is thus exposed to the oxygen of
the air, and the action of the air on the exposed part helps to make
the pain. It is not your finger, however, that hurts. It is the shock
that your brain gets when you cut your finger that hurts.

A pain in your stomach is a pain caused by something else than a cut.
If the stomach could always digest everything or any amount of stuff
you put in it, you would not have a stomach pain. But sometimes you
put things into your stomach through your mouth, of course, that the
stomach cannot handle. Or, it may be a combination of a number of
things that cause this unusual condition in your stomach. The stomach
makes a special effort to get rid of this troublesome substance and
generally succeeds eventually, but while the fight is going on, it
pains or hurts you.

Pain is the result of a disturbance of the nerves. It is just the
opposite of gladness. We sometimes are so glad we feel good all over.
Pain is just the opposite. You can prove that pain is not a real thing
but only a sensation. Perhaps you have had toothache. You go to the
dentist and he kills the nerve or takes it out. After that you cannot
have the toothache in that tooth again, because there is no nerve there
to telegraph to the brain, even though the cause of the hurt still
exists. You cannot feel pain unless the brain knows about the injury.




What Is the Horizon?


Of course you know what the horizon is. It is easiest to see the
horizon at sea when out of sight of land. There, when you look in
any direction from the ship to the place where the sea and the sky
meet you see a line which, if you follow with your eye as you turn
completely around, makes a perfect circle. It looks as though it marked
the boundary of the earth. On land it is not easy to see as much of
the horizon at one time, because of buildings and trees and hills in
the woods and elsewhere, but if the land were perfectly smooth like
the sea and there were no trees or buildings or hills in the way, you
could see just as perfect a circle on land as on sea. This proves that
the horizon is a movable circle. On land it is where the earth and sky
appear to meet, and on water it is where sky and water appear to meet.




How Far Away Is the Horizon?


The actual distance of the horizon away from us depends altogether upon
the height above the sea level from which we are looking as far as we
can. The horizon is always as far away as we can see. At the seashore,
where we are practically on a level with the water, we cannot see so
far as when we are up on a bluff or hill overlooking the sea. The
higher we go up straight from a given point the greater the distance
we can see up to a certain point and the farther away the horizon will
appear. The height of the person looking, of course, figures in this,
because when you are at sea level it is only your feet really that are
at sea level (if you are standing up straight) and the distance of the
horizon is measured from the eye of the person looking. A boy or girl
of ten would be, say, a little over four feet high, and the eyes of
such a person would be about four feet above the level of the sea. At
that height the horizon would be about two and a half miles away. If
the eyes are six feet above sea level the distance of the horizon will
be about three miles, so that practically every one sees a different
horizon, that is, one that appears at a different distance. A hundred
feet above the level of the sea the horizon will be more than thirteen
miles away, while at 1000 feet altitude it would be 42 miles away, and
if you could go a mile into the air the horizon would appear 96 miles
from where you are. The higher you go the farther away the circle which
apparently marks the joining of the earth and sky appears.




Why Can We See Farther When We Are Up High?


Remember that the earth is round and you will probably be able to
answer the question yourself. This one, like most questions boys and
girls ask, only requires a little thought. The earth, of course, as we
have learned long ago, is a globe. When you look out on the land or the
sea from a high place you can see more of the earth’s round surface
before the curve of the earth’s surface takes things beyond the range
of vision. If you are on a bluff 100 feet high at the seashore and
looking toward a point where a ship is coming toward shore, you will be
able to see the ship much sooner than if you were at the sea level. In
exact words, you actually see more of the earth’s surface the higher
up you are, because, as you go up your position in relation to the
curvature of the earth’s surface changes.




What Makes Lobsters Turn Red?


When a lobster is taken out of the lobster trap with which the
fisherman traps him, he is green, but when he comes to the table as a
choice morsel of food his shell is red. We know that he has been boiled
and we know that he goes into the boiling water green and comes out
red. This change in the color of the shell of the lobster is the result
of the effect of boiling water on the coloring material in the shell.
When the lobster is put in the boiling water the process of boiling
produces a chemical change in the color material in the lobster’s
shell. There is no particular reason why the lobster should turn red,
excepting that that is the effect boiling water has on the coloring
matter in the shell.




Why Do We Have to Die?


Death must come to all things that have life. All matter in the world
is either living (animate) or dead (inanimate). Inanimate things do not
change. They remain always the same. We can change the form and size of
inanimate things, and particles of them even help to make up the bodies
of the living things, but what they are made of always remains what it
was.

Death is one of the things that must occur if we are to continue to
have more life. The whole plan of living things includes the ability to
reproduce themselves. Every kind of life has the power to produce life
like itself and this process of reproduction is continuous. If there
were no death, then the world would soon be crowded with living things
to the point where there would be neither room nor food.

[Illustration: WHERE WINDOW GLASS COMES FROM]

  Pictures herewith by courtesy of Pittsburgh Plate Glass Co.




Making Plate Glass


What Is the Difference Between Plate Glass and Window Glass?

How is plate glass made? These questions are asked very frequently. The
two products are wholly unlike each other; and we wish to show wherein
lies the difference. We shall tell how plate glass is made; and we hope
to make it clear that great care, time and expense are involved in its
manufacture.

The raw materials may be said to be virtually the same in plate glass
as in window glass; the main difference being that in plate glass
greater care is exercised in selecting and purifying the ingredients.
Window glass is made with a blow-pipe. The work requires skill on the
part of the operator; but the process is quite simple and rapid. And
the result is, naturally, a comparatively ordinary and indifferent
product. On the other hand, the superb quality of plate glass is owing
to the elaborate method of producing it.

Commercial plate glass was first made in France somewhat more than two
hundred years ago; although glass in one form or another has been in
use for many centuries. Apparently glass was known in Egypt fully four
thousand years ago.

[Illustration: MINING SILICA]

The materials used are silica (white sand), carbonate of soda (soda
ash), and lime. Other materials, as arsenic and charcoal, are used in
small proportions, but the main ingredients are the first three named.

Probably it is little imagined that in the production of plate glass,
mining is involved in two or more forms (namely silica and coal), also
the quarrying of limestone, the chemical manufacture of soda ash on
a large scale, the reduction and treatment of fire clay to its right
consistency, an elaborate and expensive system of pot making; and the
melting, casting, rolling, annealing, grinding and polishing of the
glass.

In special uses, as in beveled plates and mirrors, two more elaborate
processes must be added--beveling and silvering--all of which are
performed under the direction of experts aided by a large amount of
labor and expensive machinery.

Pots of fire clay take so important a part in the successful
manufacture of plate glass that the subject deserves especial notice.
The different clays after being mined are exposed to the weather for
some time to bring about disintegration.

~THE CLAY MUST BE TRAMPLED WITH BARE FEET~

At the proper stage finely sifted raw clay is mixed with coarse, burned
clay and water. This reduces liability of shrinkage and cracking. It
is then “pugged,” or kneaded in a mill; kept a long time (sometimes
a year) in storage bins to ripen; and afterwards goes through the
laborious process of “treading.” Nothing has thus far been found in
machinery by which the right kind of plasticity can be developed as
does this primitive treading by the bare feet of men. The clay must be
treaded, not once or twice, but many times. The building of pots is a
slow, tedious and time-killing affair; but this is most essential.

~HOW MELTING POTS ARE MADE~

Without extreme care, some elements used in the making of the pots
might be fused into glass while undergoing the intense heat of the
furnace; or they might break in the handling. The average pot must hold
about a ton of molten glass, and the average furnace heat necessary is
about 3,000° Fahrenheit. The work is not continuous. Each workman has
several pots in hand at a time, and passes from one to another adding
only a few inches a day to each pot, so that a proper interval for
seasoning be given. After completion, comes the proper drying out of
the pots; and this is another feature in which the greatest scientific
care is required. No pot may be used until it has been left to season
for at least three months, and even a year is desirable. And after all
this trouble, the pot has but 25 days of usefulness. The pots form one
of the heavy items of expense in plate glass manufacture; and upon
their safety great things depend.

[Illustration: POT MAKING.]

[Illustration: MIXING THE CLAY.

TRAMPLING THE CLAY.]

[Illustration: SKIMMING THE POT.]

[Illustration: CASTING PLATE GLASS.]

~HOW THE HUGE PLATES OF GLASS ARE CAST~

The pot, having been first brought to the necessary high temperature,
is filled heaping full with its mixed “batch” of ground silica, soda,
lime, etc. Melting reduces the bulk so much that the pot is filled
three times before it contains a sufficient charge of metal. When the
proper molten stage is reached the pot is lifted out of the furnace
by a crane; is first carefully skimmed to remove surface impurities,
and then carried overhead by an electric tramway to the casting table.
This is a large, massive, flat table of iron, having as an attachment
a heavy iron roller which covers the full width, and arranged so as
to roll the entire length of the table. The sides of the table are
fitted with adjustable strips which permit the producing of plates of
different thicknesses. The pasty, or half-fluid glass metal is now
poured upon the table from the melting pot, and the roller quickly
passes over it, leaving a layer of uniform thickness. The heavy roller
is now moved out of the way, and then by means of a stowing tool the
red hot plate is shoved into an annealing oven. All of these stages
of the work have to be performed with remarkable speed, and by men of
long training and experience. The plates remain for several days in
the annealing oven, where the temperature is gradually reduced from an
intense heat at first, until at the end of the required period it is
no hotter than an ordinary room.

[Illustration: PREPARING THE GRINDING TABLE.]

When the plate is taken from the annealing oven it has a rough, opaque,
almost undulating appearance on the surfaces. It is only the surface,
however, for within it is as clear as crystal. First, it is submitted
for careful inspection, so that bubbles or other defects may be marked
for cutting out. It then goes to the cutter who takes off the rough
edges and squares it into the right dimensions; and thence to the
grinding room.

[Illustration: HOW THE GLASS PLATES ARE GROUND

GRINDING THE PLATES]

The grinding table is a large flat revolving platform made of iron,
twenty-five feet or more in diameter. The plate must be carried from
the annealing oven to the grinding machines, and thence to the racks,
by men skilled in the art. Twenty men are required to carry the larger
plates of glass, ten on each side, using leather straps and stepping
together in perfect time. The lock-step is absolutely essential to
prevent accident. The grinding table is prepared by being flooded with
plaster of Paris and water; then the glass is carefully lowered, and a
number of men mount upon the plate and tramp it into place until it is
set. After this, greater security is obtained by pegging with prepared
wooden pins; and then the table is set in motion. The grinding is done
by revolving runners. Sharp sand is fed upon the table, and a stream of
water constantly flows over it. After the first cutting by the sand,
emery is used in a similar manner.

The plates are inspected after leaving the grinding room, and if any
scratches or defects of any kind are found they are marked. Some of
these can be rubbed down by hand. There are also, not infrequently,
nicks and fractures found at this stage; and in such case the plate
must again be cut and squared. Afterward comes the polishing, which
is done on another special table. The polishing material is rouge, or
iron peroxide, applied with water, and the rubbing is done by blocks
of felt. Reciprocating machinery is so arranged that every part of the
plate is brought underneath the rubbing surface.

The grinding and polishing has taken away from the original plate half
of its thickness, sometimes more. There is no saving of the material;
it has all been washed away. When to this waste is added the fact that
fully half of the original weight of lime and soda has been released
by the heat of the furnace, escaping into the atmosphere in fumes and
acids, one may begin to understand something of the cost of converting
the rough materials of sand, limestone and soda into beautiful plate
glass.

~HOW MIRRORS ARE MADE~

In preparing plate glass for mirrors great care must be exercised in
the selection of the plates. This selection bears reference not only to
surface defects, but to the quality in general; defects which cannot
ordinarily be seen are magnified many fold after the glass has received
a covering of silver.

[Illustration: BEVELING PLATES]

In the process of beveling, the plate passes through the hands of
skilled workmen of five different divisions, namely: roughers,
emeriers, smoothers, white-wheelers and buffers; and different abrasive
materials are used in the order indicated by the titles. These
materials are sand, emery, natural sandstone imported from England,
pumice and rouge.

The roughing mill is a circular cast-iron disk about 28 inches in
diameter, constructed so that the face or top of the mill revolves upon
a horizontal plane at a speed of about 250 revolutions per minute. The
sand is conveyed to the mill from above through a hopper simultaneously
with a stream of water which is played upon the sand to carry it to
the mill. The rougher places the edge of the plate upon the rapidly
revolving mill, and the cutting of the bevel is done by the passage
of the sand between the mill and the plate of glass. A bevel of any
desired width may be produced. Pattern plates containing incurves,
mitres, etc., require a practiced eye and great skill upon the part of
the operator.

When the plate leaves the rougher’s hands the surface of the bevel has
been ground so deep by the coarse sand that polishing at this stage is
impossible. Consequently, in order to produce a surface fine enough
to render it susceptible of a high and brilliant polish it must go
through the various treatments we have mentioned. The emerier uses a
fine grade of emery on a mill similar in construction to a roughing
mill, which takes away considerable of the coarse surface given by the
first cutting. Then it goes to the smoother, who reduces the roughness
slowly by using a fine sandstone from England; then it goes to the
white-wheeler who operates an upright poplar-wood wheel using powdered
pumice stone as an abrasive; and then, as a last stage it reaches the
buffer, whose method of operation is shown in the illustration. The
buffer brings a high polish to the bevel by the use of rouge applied to
thick felt which covers his wheel.

[Illustration: SILVERING MIRROR PLATES.]

[Illustration: The two photographs here are of the same building taken
under contrasting conditions. The first picture was taken through a
window glazed with common window glass. It is an extreme example, to
be sure, but of a sort not infrequently seen. The second view shows
the same building taken through a window of polished, flawless plate
glass. An observing person can see this startling contrast any day as
he walks along a residence street. At intervals a front window will
be seen which gives a twisted, distorted reflection of the houses or
trees on the opposite side: this is window glass. The other kind--the
window that gives a sharp brilliant reflection--is _plate glass_. It
is practically impossible to obtain superior reflecting quality from
window glass. It can only be had from surfaces which have been ground
and polished.]

The plate, after leaving the beveling room, is again carefully examined
for surface defects. These defects may consist of scratches caused
inadvertently by permitting the surface of the plate to come into
contact with the abrasive material. These scratches are removed by hand
polishing, which must be skillfully done; otherwise the reflection will
become distorted through over-polishing in a given area or spot. The
plate is then taken to a wash table where the surface to be silvered
is thoroughly washed with distilled water; after which it is taken
to a table that is covered with blankets, and which is heated to a
temperature of from 90° to 110°. The blanketing is to protect the plate
from being scratched, and also to catch all of the silver waste. The
silvering solution is nitrate of silver liquefied by a certain formula,
and is poured over the plate; the fluid having an appearance which to
the ordinary observer looks like nothing other than pure distilled
water. Within a few minutes the silver, aided by a reactory, added
prior to pouring, begins to precipitate upon the glass; the liquids
remaining above, and thus preventing air and impurities from coming
into contact with the silver. Such contact would produce oxidation.
After the silver is precipitated the plate is thoroughly dried,
shellacked and painted; after which it is ready for commercial use.

Until about 25 years ago, practically all mirrors were silvered with
mercury. There have been two reasons for discouraging the use of
mercury for silvering; one being its injuriousness to the health of
the workmen. In some European countries stringent laws were enacted,
stipulating that men should work only a certain number of hours.

Other hygienic stipulations, added to the fact that the use of mercury
was already very expensive, have tended to replace that process by the
use of nitrate of silver.




Why Is the Sky Blue?


This question puzzled every one who thought of it for a long time.
Even astronomers, the men who make a business of studying the skies,
and other learned men, puzzled their brains about it and searched for
the answer long ago, until finally, as always happens when a lot of
people study a subject, Professor John Tyndall, a noted scientist of
the last century, discovered the answer. The explanation follows: All
the light we have is sunlight, which is pure white light. This white
light is made up of rays of light of different colors. These rays are
red, orange, yellow, green, blue, indigo and violet. It takes all of
these different rays of light to make our white sunlight, and when
you separate sunlight into its original rays you always produce the
rays of light in the above colors and in the same order. This is only
true, however, when the sunlight is passed through an object which does
not absorb any of its rays. This is the arrangement of the different
colors of light found in the rainbow. The rainbow is formed by sunlight
passing into raindrops or vapor in such a way as to divide the sunlight
into the different colored rays of light. When the rainbow is formed
none of the rays are absorbed by raindrops or vapor through which the
sunlight passes. Some of these rays of light are known as short rays
and others as long rays. But when sunlight meets other things besides
those which make a pure rainbow, these other objects have the ability
to absorb some of the rays of colored light, and they throw off the
remainder. When these rays have been thrown off those which have been
absorbed make many different combinations, and thus are produced all of
the different colors we know, the various tints and shades of color,
according to composition and size.

Now, then, to get back to the color of the sky, which is blue as we
know. The sky or air which surrounds the earth is filled with countless
tiny specks of what we may call dust--particles of solid things hanging
or floating in the air. These specks are of just the size and quality
that they catch and absorb part of the rays of light which form our
sunlight and throw off the rest of the rays, and the part which has
been absorbed forms the combination of color which makes our sky so
beautifully blue. Sometimes you notice, of course, that the sky is a
lighter or darker blue than at other times. This difference is due
to the kind and condition of tiny specks in the air at the time, and
to the direction or angle at which the sunlight strikes these tiny
particles. This fact brings up a question which you have not asked, but
which would come naturally as the result of your first.




What Makes the Colors of the Sunset?


The direction of the sun’s rays when they meet these large and small
particles in the air has a great deal to do with the combination of
colors that result as these objects absorb part of the rays and throw
off others. The sky is the most beautiful blue when the sun is high in
the sky. But when the sun is setting the light has a greater distance
to travel through the belt of air which surrounds the earth than
when it is high up over our heads. You know that if you stick a pin
straight down into an orange it won’t go in very far before it is clear
through the peel, but if you stick the pin into an orange along the
edge it will go through a great deal more of the peel than the other
way. That is the way it is with the sunset colors. The peel of the
orange is a good representation of the belt of air which surrounds the
earth. At sunset the light instead of coming straight down through the
belt of air, thus meeting the eye through the shortest possible amount
of air, strikes the air on a slant, and, therefore, travels through
a great deal more air and closer to the earth to reach it, with the
results that it meets a great many more of these little specks, besides
all the smoke and other things that hang in the air near the ground,
and we thus get many more colors, because some of the things in the air
absorb some of the rays and others absorb very different rays when the
light comes in this slanting way, and that is what makes the different
colors in the sunset. For this reason sunsets are often richer and more
beautiful in color when the air is not so pure, but has much dirt and
other matter floating about in it.




Are There Two Sides to the Rainbow?


No, there is only one side to the rainbow. The rainbow is made by
reflection of the rays of sunlight through drops of water in the air,
but you can never see a rainbow unless you are between it and the sun.
You could never see a rainbow if you were looking at the sun, and so
if you are looking at a rainbow you can be certain that anyone on
the other side of it could not see it, because they would have to be
looking right at the sun. The rainbow is always opposite to the sun and
there can never be two sides to it.




Do the Ends of the Rainbow Rest on Land?


The ends of the rainbow do not rest on anything. You see, the rainbow
is only the reflection of the sun’s rays thrown back to us by the
inside of the back of the raindrops, which are still in the sky after
the rain. Of course, if any of the drops of water touched the ground
they would cease to be raindrops and, therefore, could not reflect the
rays of the sunlight. So, what we think of as the ends of the rainbow
do not really exist at all. The rainbow is only a reflection of the
rays of sunlight from countless drops of water in the air, which the
sun’s rays must strike at a certain angle in order to reflect back the
light so we can see it. Where the sun’s rays do not strike the drops of
water at the right angle no light is reflected, and there is the end of
the rainbow.




What Causes the Different Colors of the Rainbow?


The colors of the rainbow, which are always the same, and are shown in
this order--red, orange, yellow, green, blue and violet--are sunlight
broken up into its original colors. It takes all of these colors in the
proportions in which they are mixed in the rainbow to make the pure
sunlight. These are known as the prismatic colors. As shown in another
answer to one of your puzzling questions, the rainbow is caused by the
rays of the sun passing into drops of water in the air and reflected
back to us with one part of the drop of water acting on it in such a
way as to break up the pure sunlight into these prismatic colors. When
a rainbow appears at a time when there is a great deal of sunlight, you
will generally see two rainbows. The inner rainbow is formed by the
rays of the sun that enter the upper part of the falling raindrops, and
the outer rainbow is formed by the rays that enter the under part of
the raindrops. In the inner or primary bow, as it is called, the colors
beginning at the outside ring of color are red, orange, yellow, green,
blue and violet, and being exactly reversed in the outer or secondary
bow. The secondary bow is also fainter. You may sometimes see smaller
rainbows, even if it has not been raining, when looking at a fountain
or waterfall. These are caused in exactly the same way.




What Makes the Hills Look Blue Sometimes?


This is due to the fact that when the hills look blue you are looking
at them at a distance, and there is a long stretch of air between you
and the hills. This air is filled with countless particles of dust
and other things, and what you see is not really blue hills, but the
reflection of the sun’s rays from the little particles in the air
striking your eye. The color is due to the angle at which the light
from the sun strikes these particles, and is reflected back to your eye
and partially due to the character of the particles in the air.




Do the Stars Really Shoot Down?


The answer is “No.” We have come to use the expression “shooting stars”
commonly, but we should probably be more correct if we said “shooting
rocks,” for the things we refer to commonly as “shooting stars” are
more like rocks than anything else. If any of the real stars were to
fall into the air surrounding the earth we should all be burned up by
the great heat developed long before it actually hit the earth, which
it would undoubtedly destroy.

The things that fall and leave a streak of light are really only
pebbles, stones, rocks or pieces of iron and other substances that fall
from some place into the earth’s air belt. When they strike the air
at the speed at which they are falling the friction of the air makes
a heat that causes them to become luminous, and by far the greater
part of them is burned up before they get very near the earth. We call
them meteorites. Sometimes, though rarely, one will manage to strike
the earth, coming at such great speed and being so large that the air
has not been able to burn it up completely, and it will strike the
earth and sink deep down into the soil. In most museums can be seen
such meteorites that have been dug up after striking the earth. These
are constantly falling into the air surrounding the earth, but in the
day-time their light is not strong enough to be seen while the sun is
shining.




Will the Sky Ever Fall Down?


No, the sky can never fall down, because it is not made of the kind of
things that fall. We have become used to thinking of it as the roof
of the earth, a great dome-shaped roof, because in our little way of
looking at things we compared the earth and what is above it with the
houses in which we live. The sky is just space in which the heavenly
bodies revolve in their orbits. We cannot really ever see sky. We see
only the sun’s light reflected by the air belt which surrounds the
earth. In this air belt are the clouds which do come closer to the
land at times than at others, and this is apt to aid in giving us an
incorrect impression of this.




What Is the Milky Way?


The “Galaxy,” or “Milky Way,” as it is popularly called, is a luminous
circle extending completely around the heavens. It is produced by
myriads of stars, as can be seen when you look at it through a
telescope. It divides into two great branches at one point, which
travel for some distance separately and then reunite. It has also
several branches. At one point it spreads out very widely into a
fanlike shape.




Why Do They Call It the Milky Way?


The stars in the group are so numerous that they present to the naked
eye a whiteness like a stream of milk. To produce this effect there are
not hundreds of stars, nor thousands of them, but actually millions of
them.

When you stop to think that each one of these stars in the Milky Way
is a sun like our own--some of them smaller, of course, but many of
them much larger--you begin to realize how impossible it is for man to
form any real idea of the magnitude and wonders of the earth. Here in
the Milky Way are so many suns like our own sun that they together as
we look at them form the particles of a path which makes the circle of
the heavens, and yet are so far away that to the naked eye each of them
looks to us like only one of countless drops of milk in a very large
stream of milk that goes around the whole sky.




Why Don’t the Stars Shine in the Day-time?


The stars do shine in the day-time. If you will go down into a deep
well or the open shaft of a deep mine and look up at the sky, of which
you can see a circular patch at the top of the well, you will be able
to see the stars in the day-time. The moon also shines in the day-time,
on some part of the earth. At certain times during the month you can
notice that the moon rises before the sun sets, and sometimes in the
morning you can still see the moon in the sky after the sun is up.
Usually you cannot see either the moon or the stars in the day-time,
because the light from the sun is so bright and strong that the light
of the stars and moon are lost in the brightness of the sun’s rays.
When the moon is visible before the sun sets or after the sun has risen
it is because the light of the sun is not so bright and strong at the
beginning or close of daylight. If you are fortunate enough some time
to witness a total eclipse of the sun you will be able to see the stars
in day-time without having to go down into a deep well or mine shaft.




How Far Does Space Reach?


Space surrounds all earths, planets, suns, and extends for an infinite
distance beyond each of them in all directions. It is impossible to
measure in terms of human knowledge how far space extends. It is one
of the things beyond the comprehension of the human mind, and for that
reason man can never know in miles or the number of millions of miles
how far it extends. Man has been able to measure the distance from
the earth of some of the stars, and some of the nearest of them are
millions of miles from the earth. Most of them are hundreds and even
thousands of million miles away, and when we stop to think that space
extends at least as far on the other sides of the stars as it does on
this side, and even beyond that, we can readily understand that it is
not only impossible to measure space, but also impossible to give in
words any conception of what its limits might be.

There is one word--infinite--which we are forced to use in speaking of
the extent of space. Infinite means “without end,” unbounded, and so
man has come to use the word “infinite” in describing the extent of
space, and that is as near as any one can describe it.




What Does Horse Power Mean?


The term “horse power” is used in describing the amount of power
produced by an engine or motor. When man made the first engines he
needed some term to use in describing the amount of power his engine
could develop. Up to that time man had used the horse for turning the
wheels of his machinery and the horse to him naturally represented the
most powerful animal working for man. When engines came into use they
replaced the horses because they were capable of developing many times
the power of the horse. In finding an expression which would accurately
convey to the mind of another the power of a particular engine, it
was natural to say that this engine would do the work of five, ten or
more horses, and as this described it accurately and in a way that was
entirely clear, it became customary to describe the power of an engine
as so many times the power of one horse.

To-day we still cling to the term “horse power” in describing the
strength of the engine, although the horse-power unit used to-day is
greater than the power of an average horse. To speak of an engine of
one horse power to-day means an engine that has the power to lift
30,000 pounds one foot in one minute.

[Illustration: WHERE OUR COAL COMES FROM

A COAL BREAKER.

Coal is brought in mine cars from several mine shafts and slopes,
dumped onto a conveyor that runs on the inclined framework shown at
the right of the picture. At the top it is broken in rolls, sorted and
sized as it slides through the different screens, pickers, etc., and is
finally delivered into railroad cars.]




The Story in a Lump of Coal


How Did the Coal Get Into the Coal Mines?

The heavy black mineral called coal, which we burn in our stoves
and furnaces, and use to heat the boilers of our engines was formed
from trees and plants of various sorts. Most of the coal was formed
thousands of years ago at a time when the atmosphere that envelopes the
earth contained a much larger proportion of carbonic acid gas than it
does now, and the climate of all regions of the earth was much warmer
than it now is. This period was known as the carboniferous age, that
is, the coal-making age, and its atmospheric conditions, favored the
growth of plants, so that the earth was covered with great forests,
of trees, giant ferns, and other plants, many of which are no longer
found on the earth. In the warm, moist, and carbon-laden atmosphere of
that period the growth of all kinds of plants was rapid and luxuriant,
and as fast as old trees fell and partially decayed, others grew up in
their places. In this way, thick layers of vegetable matter were formed
over the soil in which the plants grew. In many places, where these
beds were formed, the surface of the earth became depressed and the
water of the sea flowed over the beds of vegetable matter.

Sediment of various kinds was deposited over the vegetable matter, and
in the course of centuries the sediment was transformed into rock.

After the formation of the covering of sediment, the decay of the
vegetable matter was checked, but a slow change of another kind was
brought about by the pressure of the sedimentary deposits and the heat
to which the plant remains were subjected. The hydrogen and oxygen
which constituted the greater part of the plant substance was driven
off and the carbon left behind. This change took place very gradually,
through periods so long that we can only guess at their duration, but
we know that many beds of coal were formed from layers of vegetable
matter that were covered up many thousand years ago.

[Illustration: MINE WORKERS THAT NEVER SEE DAYLIGHT

Underground stable constructed of concrete and iron, with natural rock
roof to avoid danger of fire. Mules are only taken to surface when
mines are idle.]

The coal first formed and submitted longest to pressure is known as
hard coal, or anthracite. It is pure black, or has a bluish metallic
luster. Its specific gravity is 1.46; which is about the same as that
of hard wood. Anthracite contains from 90 to 94 per cent. of carbon,
the remainder being composed of hydrogen, oxygen, and ash.

[Illustration: The Mules and their drivers.--An important part of the
haulage system. Mules are kept in stables on surface at this mine and
driven in every day through slope or drift.]

Hard coal may be called the ideal fuel and is especially adapted to
domestic heating purposes. It burns without smoke and produces great
heat. There is no soot deposit upon the walls of chimneys, and in good
stoves or furnaces the small amount of gas given off by it is consumed.
Anthracite is the least abundant of all the varieties of coal and is
much more costly than the other varieties. For this reason it is not
much used in manufacturing.

[Illustration: HOW THE SLATE PICKERS WORK

Boy slate pickers. Coal slides down the chutes. Boys pick out the slate
and rock and throw into chute alongside.]

[Illustration: Spiral slate pickers do work of many boys. Coal and rock
start together at the top in the small inner spiral. The coal being
lighter slides faster, and in going around is carried over the edge
into the outer spiral, while the rock continues in the bottom.]

The coal formed later is very different in composition and is called
bituminous or soft coal. Its name is derived from the fact that it
contains a soft substance called bitumen, which oozes out of the coal
when heat is applied to it. Soft coal contains from 75 to 85 per cent.
of carbon, some traces of sulphur, and a larger percentage of oxygen
and hydrogen than anthracite. When soft coal is heated in a closed
vessel or retort, the hydrogen and oxygen, in combination with some
carbon, are driven off.

[Illustration: HOW A COAL MINE LOOKS INSIDE

Shaft gate. One of the two cages in the shaft has just brought the men
to the surface; the other is at the bottom. Safety gate resting on top
of cage covers top of shaft when cage is down, as shown at right.]

[Illustration: Section showing Anthracite Seams. Coal is shown black;
rock and dirt lighter; shaft tunnels and workings, white. Upper part of
“Mammoth” seam is stripped and quarried.]

[Illustration: Lignite mine in Texas. Loaded mine cars ready to go to
surface.]

[Illustration: HOW THE MINERS LOOSEN THE COAL

Undercutting with pick. The man lying on his side cuts under the coal.
A light charge of powder exploded in a drill hole near the roof breaks
the coal down in large pieces.]

Soft coal is black, and upon smooth surfaces it is glossy. It lacks the
bluish luster sometimes seen in hard coal and is much softer and more
easily broken. When handled it blackens the hands more than hard coal
does. In this kind of coal are frequently seen the outlines of leaves
and stems of plants that enter into its formation. Occasionally, trunks
of trees with roots extending down into the clay below the bed of coal
have been found.

[Illustration: Undercutting in seam. A compressed air driven machine
undercuts deeper and faster than the man with a pick.]

Soft coal has a specific gravity of 1.27. It burns with a yellow flame
which is larger than the flame from hard coal, but it does not emit so
high a degree of heat. Combustion, generally imperfect, gives rise to
offensive gases and to black smoke that concentrates in the air and
falls to the ground as soot, which blackens buildings, and, in winter,
noticeably discolors the snow.

The formation of lignite has been observed in the timbers of some
old mines in Europe. In some of these mines wooden pillars have been
supporting the rocks above for four hundred years or longer, and in
that time the pressure of the rocks and other influences acting upon
the wood of the pillars have caused it to become transformed into a
brown substance resembling lignite. This fact tends to confirm the
theory of coal formation stated at the beginning of this article. The
proportion of carbon in lignite is never above 70 per cent., and the
ash indicates the presence of considerable earthy matter. It is chiefly
used in those forms of manufacture where a hot fire is not required. In
Europe it is used, to some extent, in heating the houses of the poorer
classes.

Peat is regarded as the latest of the coal formations. In it, the
change in the vegetable matter has not extended beyond merely covering
it, and subjecting it to slight pressure.

Peat is formed in marshy soils where there is a considerable growth
of plants that are constantly undergoing partial decay and becoming
covered by water. It consists of the roots and stems of the plants
matted together and mingled with some earthy material. When freshly
dug out of the bog or marsh in which it was formed there is always a
quantity of water in it, the amount being greatest in the peat found
nearest the surface and least in that at the bottom of the bed, where
the peat is not very different in appearance from lignite.

Peat is used for fuel where wood is scarce and coal is high in price.
Recent experiments in saturating peat with petroleum, have shown that
in this way a form of fuel may be produced for which considerable value
is claimed. Its manufacture is confined to Southern Russia, where peat
is plentiful and petroleum is cheap.


Why Does Firedamp Explode in a Safety Lamp Without Producing an
Explosion of the Gas With Which the Lamp Is Surrounded?

The passing of the flame from the lamp to the outside air is prevented
by the gauze. This splits the burning gas into little streamlets (784
to each square inch of gauze), which are cooled below the point of
ignition, that is, are extinguished by coming in contact with the metal
of the gauze, so that the flame does not pass outside the lamp. In some
cases the explosion may be so great as to force the flame through the
gauze and thus ignite the gas outside.


Are There Any Conditions Under Which it Would Not Be Safe to Use a
Safety Lamp?

~THE DANGERS TO THE MINERS~

The underground conditions affecting the safety of the lamp are
exposure in air-currents of high velocity by reason of which the flame
may be blown through or against the gauze, or exposure for too great
a time to mixtures of air and gas which will burn within the lamp and
thus heat the gauze. The dangerous velocity of air-currents begins at
about 500 feet a minute, but varies with the type of lamp, some being
much less sensitive to air-currents of high velocity than others. Other
conditions under which the lamp is not safe concern the lamp itself or
the one using it. The lamp is dangerous in the hands of inexperienced
persons or when the gauze is dirty or broken. If the gauze is dirty,
that portion absorbs the heat and may become hot enough to ignite the
outside gas; naturally any holes in the gauze will pass the flame.

The safety lamp when left too long in air containing much explosive gas
may cause an explosion, and it is extinguished by certain unbreathable
gases. The electric lamp burns safely regardless of the atmosphere,
but gives no warning of poisonous or explosive gases. It is often used
by rescue men wearing oxygen helmets to enter mines full of poisonous
gases after explosions.

[Illustration: THE LAMP WHICH SAVES MANY LIVES

The safety lamp. The sheet iron bonnet or covering of the upper part
protects the gauze within from strong currents of air, while the glass
permits the light to be diffused. The above is a modern lamp similar to
a bonnetted Clanny lamp.]

The safety lamp is dangerous when there is a hole in the gauze that
will permit the passage of flame to the outside, or when the gauze
is dirty, so that any particular spot may be overheated, or when the
velocity of the air is so great that the flame is blown through the
gauze, or (generally) when in the hands of an inexperienced person. The
unbonneted Davy lamp is not safe where the velocity of the air exceeds
360 feet per minute. The velocity with which the air strikes a lamp
carried against it is increased by the amount equal to the rate at
which the fireboss travels. If he walks at the rate of, say, 4 miles an
hour or 352 feet a minute (on the gangways he will usually have to move
faster than this to make his rounds on time) he will create by his own
motion (and in still air) a velocity practically the same as that at
which the unbonneted Davy is considered unsafe.

[Illustration: Open oil lamp commonly worn on hat. Wick is inverted in
spout.]

[Illustration: Acetylene or carbide lamp for cap or hand.]


History of the Safety Lamp.

The safety lamp, the miner’s faithful and indispensable companion at
his dangerous work, has been, heretofore, considered as the invention
of the famous English scientist, Humphrey Davy, though the name of
George Stephenson, of locomotive fame, has also been mentioned in
this connection. Both came out with their inventions about the same
time, but neither of them is the real inventor of the safety lamp; for
there was, as proven by Wilhelm Nieman, a safety lamp in existence two
years before Davy’s invention became known. It was not inferior to the
latter, but rather surpassed it in illuminating power. Previous to
this, all the precaution employed for the prevention of the threatening
dangers of firedamp had been quite incomplete. One tried to thoroughly
ventilate the mines by fastening a burning torch to a large pole, which
was pushed ahead and exploded the gases. This was extremely dangerous
work which, in the Middle Ages, was generally done by a criminal,
in order that he might atone for his crimes, or by a penitent for
the benefit of mankind. The attempt to substitute for the open light
phosphorescent substances, encased in glass, was not much of a success.
An improvement was the so-called steel mill, invented about 1750 by
Carlyle Spedding, manager of a mine. This steel mill consisted of a
steel wheel which was put into rapid motion by means of a crank. By
pressing a firestone against the fast revolving wheel, an incessant
shower of sparks was produced giving a fairly good and absolutely safe
illumination. However, the running expenses of his apparatus, which
necessitated the continual services of one man, were very high; for
instance, the expenditure for light in a coal mine near Newcastle in
the year 1816 amounted to about $200 per week. Nevertheless, the steel
mill was very much appreciated and in use for a long time, only to be
slowly supplanted by the safety lamp.

[Illustration: ELECTRIC CAP LAMP AND BATTERY.

The safety lamp when left too long in air containing much explosive gas
may cause an explosion, and it is extinguished by certain unbreathable
gases. The electric lamp burns safely regardless of the atmosphere,
but gives no warning of poisonous or explosive gases. It is often used
by rescue men wearing oxygen helmets to enter mines full of poisonous
gases after explosions.]

~THE MAN WHO INVENTED THE SAFETY LAMP~

At the beginning of the nineteenth century the existing coal mines
were worked to the limit and the catastrophies, caused by firedamp,
increased in an alarming manner. In fact the distress was so great that
in 1812 a society for the prevention of mine disasters was formed at
Sutherland, and the origin of the safety lamp can be traced back to
the efforts and labors of this organization. Dr. William Reid Clanny,
a retired ship’s surgeon, was probably the first to undertake the task
(in the year 1808), which he successfully finished with energy and
skill. He concentrated his efforts at first on the separation of the
flames from the surrounding atmosphere, but he did not succeed till the
latter part of 1812, when he constructed a lamp that seemed to meet
all requirements. The report of this invention was submitted to the
Royal Society of London, May 20, 1813, and was printed in the minutes
of that academy. The casing of this original safety lamp was closed
at the top and bottom by two open water tanks; the air was pumped in
by means of bellows and, passing in and out, had to go through both
these reservoirs which acted as valves, so to speak. The lamp proved to
be absolutely safe and was successfully introduced by the management
of Herrington Mill pit mine. The clumsy parts of this apparatus were
eliminated by its inventor by various improvements. The so-called steam
safety lamp was completed in December, 1815, and installed in several
mines. In the meanwhile, two competitors made their appearance. George
Stephenson had finished his lamp October 21, 1815, and Davy published
his first experiments November 9, 1815, in the Transactions of the
Royal Society of London. Clanny’s lamp, nevertheless, stood the test in
the face of this competition, through its much superior illuminating
power, and more particularly as it still continued to burn when the
Davy and Stephenson lamps had gone out. To Clanny, therefore, belongs
the distinction, in the history of invention, of having constructed the
first reliable safety lamp.




What Is a Metal?


The oldest known metals in the world are gold and silver, copper, iron,
tin and lead. They are to-day still the most useful and widely-used
metals. Some of the properties by which we distinguish metals are the
following: They are solid and not transparent; they have luster and
are heavy. Mercury is an exception to the rule; it is a liquid, though
yet a metal, and there is another, sodium, which is solid, though very
light.




What Is the Most Valuable Metal?


If you were guessing you would naturally say that gold is, of course,
the most valuable of the metals. But you would be wrong. The proper
answer to this is iron. We do not mean the pound for pound value, for
you could get much more for a pound of gold than for a pound of iron.
We mean in useful value--iron is in that sense the most valuable metal
known to man. This is true because iron is of such great service to man
in so many ways, and it is very fortunate that there is such a great
amount of it available for man’s purposes. Iron is not generally found
in a pure state in the mines. It is generally found compounded with
carbon and other substances, and we obtain pure iron by burning these
other substances out of the compound.

Iron is put upon the market in three forms, which differ very much in
their properties. First, there is cast-iron. Iron in this form is hard,
easily fusible and quite brittle, as you will know if you ever broke a
lid on the kitchen range. In the form of cast-iron it cannot be forged
or welded.

Next comes wrought-iron, which is quite soft, can be hammered out flat
or drawn out in the form of a wire and can be welded, but fusible only
at a high temperature. Third comes steel, the most wonderful thing we
produce with iron. It is also malleable, which means that it is capable
of being hammered out flat and can easily be welded, and this is the
great property of steel--it acquires when tempered a very high degree
of hardness, so that a sharp edge can be put on it, and when in that
shape it will easily cut wrought-iron. Ordinarily we make wrought-iron
and steel from iron that has been changed from its original state to
cast-iron.

The term cast-iron is generally given to iron which has been melted and
cast in any form desired for use. Stoves are made in this way. The iron
is melted and then poured into a mold; while the product out of which
wrought-iron and steel are made is technically cast-iron, the term
pig-iron is used in speaking of iron which is cast for this purpose.

The process by which pig-iron is changed into wrought-iron is called
_puddling_. The object of puddling, which is done in what is called a
reverberatory furnace (which is a furnace that reflects or drives back
the flame or heat) is to remove the carbon which is in the pig-iron.
This is done partly by the action of the oxygen of the air at high
temperature and partly by the action of the cinder formed by the
burning furnace. When this has been done the iron is made into balls of
a size convenient for handling. These are “shingled” by squeezing or
hammering and passed between rolls by which the iron is made to assume
any desired form.

Now we come to steel, the most wonderful product or form in which we
take advantage of the value of iron. Steel was formerly made from
wrought-iron, so that you first had to get cast-iron, from which
you made wrought-iron, and eventually got steel by changing the
wrought-iron. Now we make steel direct from pig-iron. This is known as
the Bessemer process.

The most noticeable feature in the chemical composition of the
different grades of iron and steel is found in the percentages of
carbon they contain. Pig-iron contains the most carbon; steel the next
lowest, and wrought-iron the least.

Iron has been known to men from early historical times. The smelting
of iron ores is not any indication of advanced civilization either.
Savage tribes in many parts of the world practiced the art of smelting,
even before they could have learned it from people who had become
civilized.




Why Is Gold Called Precious?


Gold is called one of the precious metals because of its beautiful
color, its luster, and the fact that it does not rust or tarnish when
exposed to the air. It is the most ductile (can be stretched out into
the thinnest wire), and is also the most malleable (can be hammered
out into the thinnest sheet). It can be hammered into leaves so thin
that light will pass through them. Pure gold is so soft that it cannot
be used in that form in making gold coins or in making jewelry. Other
substances, generally copper, are added to it to make the gold coins
and jewelry hard. Sometimes silver is also added to the gold with
copper. The gold coins of the United States are made of nine parts of
gold to one of copper. The coins of France are the same, while the
coins of England are made of eleven parts of gold to one of copper.
The gold used for jewels and watch-cases varies from eight or nine to
eighteen carats fine.

Another reason why gold is called a precious metal is that it is very
difficult to dissolve it. None of the acids alone will dissolve gold,
and only two of them when mixed together will do so. These are nitric
acid and hydrochloric acid. When these two acids are mixed and gold put
into the mixture the gold will disappear.




What Do We Mean By 18-Carat Fine?


We often hear people in speaking of their watches say, “It is an
18-carat case.” Others speak of 14-carat watches or 22-carat or
solid-gold rings.

When you see the marks on a watch-case or the inside of a gold ring
they read 18 K or 14 K, or whatever number of carats the maker wishes
to indicate. A piece of gold jewelry marked 18 K or 18 carats means
that it is three-fourths pure gold. In arranging this basis of marking
things made of gold, absolutely pure gold is called 24 carats. Then if
two, six or ten twenty-fourths of alloy has been added, the amount of
the alloy is deducted from twenty-four, and the result is either 22, 18
or 14 carats fine, and so on. On ordinary articles made by jewelers the
amount of pure gold used is seldom over 18 carats, or three-fourths.
Weddings rings (and these are considered solid gold) are generally made
22 carats fine, that is, there are only two twenty-fourth parts of
alloy in them.




Why Does Silver Tarnish?


Silver is a remarkably white metal, which is associated with gold as
one of the precious metals. It is harder than gold and will not rust,
although it will tarnish, which gold will not, when exposed to certain
kinds of air.

The silver tarnishes when it is exposed to any kind of air that has
sulphur mixed in it. It ranks below gold as a precious metal for use in
making ornaments and is not so costly, because there is a great deal
more of it to be found in the world.

While silver is somewhat harder than gold, it is still not sufficiently
hard to use pure for making coins, so, as in the case of the gold
coins, it is mixed with something else--copper--to harden it. Otherwise
our dimes and quarters would wear out too rapidly. Our silver coins are
made of nine parts of silver to one of copper. The coins of France are
in the same proportion, while the silver coins of England are made of
92¹⁄₂ parts of silver to 7¹⁄₂ parts of copper. German silver coins are
made of three parts of silver and one of copper.




Why Do We Use Copper Telegraph Wires?


One of the characteristics which distinguishes copper is its color--a
peculiar red. It stands next to gold and silver in ductility and
malleability, and comes next to iron and steel in tenacity--which
means the ability of its tiny particles to hang on to each other.
That is why copper wire bends instead of breaking when you twist
it. But that is not the only reason, although an important part of
the reason, why we use copper for telegraph wires. Copper is an
extremely good conductor of electricity when it is pure. So are gold
and silver, but we cannot afford to buy gold and silver wires for the
telegraph, telephone and other wires, and if we used such wires the
cost of the equipment would be so great that we could not afford to
have telephones in our homes. But there is a great deal of copper in
the world and it is very cheap, and so it makes an ideal element for
use in things through which electricity is to pass. When you compound
it with other substances it loses some of its conductivity. Copper
is used extensively in many ways in the world. This book is printed,
for instance, from copper electrotype plates. The whole business of
electrotyping is based on the use of copper.




Why Is Lead So Heavy?


Lead is a white metal and is noted for its softness and durability. It
has a luster when freshly cut, but becomes dull quite soon after the
freshly-cut surface is exposed to the air. Lead is the softest metal in
general use. It can be cut with an ordinary knife. It can be rolled out
into thin sheets, but cannot be drawn out into wire.

Lead is a very dense metal, that is, its particles are very compact
and there is no room for air to circulate in between these particles.
A piece of wood is lighter than a piece of lead of exactly equal bulk,
because the little particles which make up the piece of wood are not
very close together, and there is a lot of air in the ordinary piece of
wood, while this is not true of the lead.

A great deal of lead is used in making pipes for plumbing. This is
because lead pipe is comparatively cheap, although you might not think
so when you think of the general conclusions we have been brought to
form about plumbers and everything connected with them. Lead pipe is
easily bent in any direction also, and is particularly good for use in
plumbing for that reason.

Another wide use of lead is in making paints--white lead being the base
used in making oil paints. The process of making white lead for paint
is quite interesting and pictures of it are shown in “The Story In a
Can of Paint” in another part of “The Book of Wonders.”




Why Are Cooking Utensils Made of Tin?


Tin is the least important of the six useful metals. It is also
inferior in many ways to the others in this group of elements, but is
tougher than lead and will make a better wire, though not a really good
one. It has a whiteness and a luster that are not tarnished by ordinary
temperature and is cheap. That is why it is used in making cooking
utensils, pans, etc., and for roofs. But the pans, roofs, etc., are not
pure tin. They are thin sheets of iron coated with tin. Pure tin would
not be strong enough for these purposes, so a sheet of iron is first
taken to supply the strength and then covered with tin to improve the
appearance of the tin pans and keep them from rusting rapidly.




What Is Gravitation?


Gravitation is the result of the attraction which every body, no matter
what its size, has for every other body. It is a strange force and
difficult to explain in plain words. It is what keeps the heavenly
bodies in their paths. Every one of the planets is held in its path
by gravitation and every object on each of the planets is kept on the
planet by gravitation. We can come nearer understanding gravitation by
studying the effect of the attraction of gravitation on our own earth
and the objects on it. When you throw a ball or a stone into the air
it is the attraction of gravitation that causes it to come back. If
this were not so the stone would go on up and up and would keep on
going forever. If it were not for this wonderful force you could jump
into the air and just keep on going up with nothing to bring you back.
The reason you do not pull the earth toward you is because the body or
mass with the greater bulk has always the greater pulling power.

This is a wonderful force. It cannot be produced nor can it be
destroyed or lessened. It just is. It acts between all pairs of
bodies. If other bodies come between any pair of bodies the attraction
of gravity between the two outside bodies is neither lessened or
increased, and yet each of the outside bodies will have an independent
attraction or pull on the body which is in between.

No particle of time is spent by the transmission of the force of
gravity from one body to another, no matter how far apart they may be.
The only effect that distance has on the attraction of gravitation is
to lessen its force. Any body which is being pulled through gravity
toward another body would fall toward the center of the attracting body
if all the force of attraction from all other bodies were removed.




What Is Specific Gravity?


Specific gravity is the ratio of weight of a given bulk of any
substance to that of a standard substance. The substances taken as
the standard for solids and liquids is water, and air or hydrogen for
gases. Since the weights of different bodies are in proportion to their
masses, it follows that the specific gravity of any body is the same
as its density, and we now generally use the term “density” instead of
specific gravity.

To find, for instance, the specific gravity of a given bulk of silver,
we must take an equal bulk of water and weigh it. Then we also weigh
the silver. We find that the silver weighs ten and a half times as much
as the water, and so the specific gravity of silver is 10.5. If you
will bear in mind that water is the standard used for measuring the
specific gravity of solids and liquids, and that air or hydrogen are
used as standards for the gases, you will always know what the figures
after the words specific gravity mean.




Why Do We See Stars When Hit On the Eye?


We do not really see stars, of course, when we are hit on the eye or
when we fall in such a way as to bump the front of our heads. What we
do see, or think we see, is light.

To understand this we must go back to the explanation of the five
senses--sight, hearing, feeling, tasting and touching. Now, each of
these senses has a special set of nerves through which the sensations
received by each of the senses is communicated to the brain and, as
a rule, these special nerves receive no sensations excepting those
which occur in their own particular field of usefulness. The eye then
has nerves of vision; the nose, nerves of smell; the ear, nerves of
hearing; the mouth, nerves of taste, and the entire body nerves of
touch. As we have seen then, these special nerves are susceptible of
receiving impressions or sensations only in their particular field.
But, if you should be able to rouse the nerves of smell in an entirely
artificial way and give them a sensation, they might easily act very
much as though they smelled something. We find this often in the nerves
of touch when we think we feel something when we do not.

Now, when some one hits you in the eye, the nerves of vision are
disturbed in such a way as to produce upon the brain the sensation of
seeing light. In other words, you cannot affect the eye nerves without
causing the sensation of light, and that is just what happens when some
one hits you in the eye.

[Illustration: “ARGONAUT, JUNIOR.”

Experimental Boat, 1894.]

[Illustration: “ARGONAUT THE FIRST.”

Built 1896-1897.]




The Story in a Submarine Boat


How Can a Ship Sail Under Water?

Up to a few years ago the stories we could tell about the ships that
sail beneath the water were the creations of the minds of writers of
fiction, like the author of “Twenty Thousand Leagues Under the Sea,”
but to-day we can read of many actual trips beneath the water by the
brave men who man our submarines. We never dreamed that the great story
of Jules Verne would be realized in the little but very destructive
ships of war which can be seen to-day in the naval ports of the nations
of the world.

We might have had these submarines long ago but for the fact that the
men who were trying to invent them would not give up the secrets which
they had discovered. Many men in different parts of the world worked on
this problem and each discovered one or more things which were valuable
in working out a solution, and if they had all gotten together and
compared notes between them they could have produced a submarine boat
almost as good as those we have to-day.


How Does the Submarine Get Down Under the Surface?

The first essential in a vessel to enable it to navigate below the
surface of the water is that it be made sufficiently strong to
withstand the surrounding pressure of water, which increases at the
rate of .43 of a pound for each foot of submergence.

A boat navigating at a depth of 100 feet would therefore have 43 pounds
pressure per square inch of surface, or 6192 pounds for every square
foot of surface. It will readily be seen, therefore, that the first
essential is great strength. Therefore, the submarine boats are usually
built circular in cross section with steel plating riveted to heavy
framing, as that is the best form to resist external pressure. These
boats are built for surface navigation as well, therefore they have a
certain amount of buoyancy when navigating on the surface, the same as
an ordinary surface vessel. When it is desired to submerge the vessel
this buoyancy must be destroyed, so that the vessel will sink under the
surface.

Now, the submerged displacement of a submarine vessel is its total
volume, and, theoretically, a vessel may be put in equilibrium with the
water which it displaces by admitting water ballast into compartments
contained within the hull of the vessel, therefore, if a vessel whose
total displacement submerged was 100 tons, the vessel and contents must
weigh also 100 tons. If it weighed one ounce more than 100 tons it
would sink to the bottom. If it weighed one ounce less than 100 tons it
would float on the surface with a buoyancy of one ounce. If it weighed
exactly 100 tons it would be in what submarine designers specify as
being “in perfect equilibrium.”

It is possible to give a vessel a slight negative buoyancy to cause
her to sink to, say, a depth of 50 feet and then pump out sufficient
water to give her a perfect equilibrium, and thus cause her to remain
at a fixed depth while at rest. In practice, however, this is seldom
done. Most submarine boats navigate under the water with a positive
buoyancy of from 200 to 1000 pounds and are either steered at the depth
desired by a horizontal rudder placed in the stern of the vessel, or
are held to the depth by hydroplanes, which hydroplanes correspond to
the fins of a fish. They are flat, plane surfaces, extending out from
either side of the vessel, and when the vessel has headway, if the
forward ends of these planes are inclined downward, the resistance of
the water acting upon the planes is sufficient to overcome the reserve
of buoyancy and holds the vessel to the desired depth. If the vessel’s
propeller is stopped, the boat, having positive buoyancy, will come to
the surface.

By manipulating either the stern rudders or the hydroplanes, the vessel
may be readily caused to either come nearer to the surface or go to
a greater depth, as the change of angle will give a greater or less
downpull to overcome the reserve of buoyancy.

The above description applies to navigating a vessel when between the
surface of the water and the bottom.

Another type of vessel which is used for searching the bottom in
locating wrecks, obtaining pearls, sponges, or shellfish, is provided
with wheels. In this type of vessel the boat is given a slight negative
buoyancy, sufficient to keep it on the bottom, and it is then propelled
over the water bed on wheels, the same as an automobile is propelled
about the streets. This type of vessel is also provided with a diver’s
compartment, which is a compartment with a door opening outward from
the bottom. If the operators in the boat wish to inspect the bottom,
they go into this compartment and turn compressed air into the
compartment until the air pressure equals the water pressure outside
of the boat; i. e., if they were submerged at a depth of 100 feet they
would introduce an air pressure of 43 pounds per square inch into the
diving compartment. The door could then be opened and no water could
come into the compartment, as the diving compartment would be virtually
a diving bell. Divers can then readily leave the boat by putting on a
diving suit and stepping out upon the bottom.

[Illustration: ONE OF THE FIRST PRACTICAL SUBMARINES

“PROTECTOR.” BUILT 1901-1902, BRIDGEPORT, CONN.

This was the pioneer Submarine Torpedo Boat of the level-keel type, and
was built in Bridgeport in 1901-1902. It was shipped to St. Petersburg,
Russia, during the Russian-Japanese war. From St. Petersburg it was
shipped to Vladivostok, 6000 miles across Siberia, special cars being
built for its transport.]

[Illustration: This picture illustrates the same vessel, also at full
speed under engines, with the conning-tower entirely awash and with
the sighting-hood and the Omniscope alone above water. Notwithstanding
the limited areas exposed above the surface, still observation could
be had well-nigh continuously either through the dead-lights in the
sighting-hood or by means of the Omniscope.

In neither condition is it necessary to have recourse to electrical
propulsion--the boats can still be safely and speedily driven as here
shown under their engines.]

[Illustration: THE INSIDE OF A SUBMARINE

THE “G-1” RECENTLY DELIVERED TO THE UNITED STATES GOVERNMENT.

The largest, fastest submarine in the United States and the most
powerfully armed submarine torpedo boat in the world.

In addition to the usual fixed torpedo tubes arranged in the bow of the
vessel, which requires the vessel herself to be trained, the (seal)
“G-1” carries four torpedo tubes on her deck which may be trained while
the vessel is submerged, in the same manner as a deck gun on a surface
vessel is trained, and thus fired to either broadside, which gives many
technical advantages.]

[Illustration: The above view gives a general idea of the interior
of a submarine torpedo boat and the method of operation when running
entirely submerged with periscope only above the surface.

The commanding officer is at the periscope in the conning tower
directing the course of the submarine through the periscope, which
is a tube arranged with lenses and prisms which gives a view of the
horizon and everything above the surface of the water, the same as if
the observer in the submarine was himself above water. The steersman is
shown just forward of the commanding officer and steers the vessel by
compass under the direction of the commanding officer, the same as when
navigating above the surface. In the larger type boats the steersman
also has a periscope which enables him to see what is going on above
the surface. Below decks two of the crew are shown loading a torpedo
into the torpedo tube; each torpedo is charged with gun-cotton and
will run under its own power over a mile and will explode on striking
the enemy. The crew live in the compartment aft of the torpedo room.
Aft of this is the engine room, in which are located powerful internal
combustion engines for running on the surface and electric motors for
running submerged. The electric motors are driven by storage batteries
located under the living quarters. Wheels are shown housed in the keel,
which may be lowered for navigating on the bottom in shallow water.
A diving compartment in the bow permits divers to leave the vessel
when on the bottom, to search for and cut or repair cables or to plant
mines.]

[Illustration: A SUBMARINE SAILING CLOSE TO THE SURFACE

A submarine running partly submerged with the conning tower hatch
open, showing the remarkable steadiness of this type of boat in
a semi-submerged condition, a thing no other craft could safely
accomplish.]

[Illustration: Another submarine running entirely submerged, periscope
only showing. The flag is attached to top of periscope to show her
position in maneuvers when periscope goes entirely under water.]

[Illustration: A PHOTOGRAPH TAKEN WITH THE PERISCOPE UNIVERSAL LENS.]


AN ALL-SEEING EYE FOR THE SUBMARINE

Vision under water is limited to but a few yards at best, and hence
a submarine boat, when submerged, would be as blind as a ship in a
dense fog and would have to grope its way along guided only by chart
and compass, were it not for a device known as a periscope, that
reaches upward and projects out of the water, enabling the steersman
to view his surroundings from the surface. Of course the height of the
periscope limits the depth at which the craft may be safely sailed. Nor
can the periscope tube be extended indefinitely, because the submarine
must be capable of diving under a vessel when occasion demands. But
when operating just under the surface, where it can see without being
seen, the craft is in far greater danger of collision than vessels
on the surface, because it must depend upon its own alertness and
agility to keep out of the way of other boats. The latter can hardly be
expected to notice the inconspicuous periscope tube projecting from the
water in time to turn their great bulks out of the danger course.

The foregoing article describes the type of periscope now in common
use on submarines and one of the engravings on this page clearly
illustrates the principles of the instrument. A serious defect of this
type of instrument is that the field of vision is too limited. The man
at the wheel is able to see under normal conditions only that which
lies immediately before the boat. It is true that he can turn the
periscope about so as to look in other directions, but this, of course,
involves considerable inconvenience. On at least two occasions has a
submarine boat been run down by a vessel coming up behind it.

[Illustration]

~SEEING IN ALL DIRECTIONS AT ONCE~

As long as the submarine has but a single eye it would seem quite
essential to make this eye all-seeing; and since the two lamentable
accidents just referred to, an inventor in England has devised a
periscope which provides a view in all directions at the same time.
This has been attempted before, but it has been found very difficult
to obtain an annular lens mirror which would project the image down
the periscope tube without distortion. The accompanying illustrations
show how this difficulty has now been overcome. While we will not
attempt to enter into a mathematical explanation of the precise form
of the mirror lens, it will suffice to state that it is an annular
prism. The prism is a zonal section of a sphere with a conoidal central
opening and a slightly concave base. All the surfaces, however, are
generated by arcs of circles owing to the mechanical inconvenience
of producing truly hyperboloidal surfaces. The lens mirror is shown
in section at _A_ in Fig. 1. The arrows indicate roughly the course
of the rays into the lens and their reflection from the surface _B_,
which is preferably silvered. The tube is provided with two objectives
_C_ and _D_ (Fig. 3) between which a condenser _E_ is interposed at
the image plane of the lens _C_. At the bottom of the periscope tube
the rays are reflected by means of a prism _F_ into the eyepiece. Two
eyepieces are employed. One of lower power, _G_, is a Kelner eyepiece,
the purpose of which is to permit inspection of the whole image, while
a high-powered eccentrically placed Huyghenian eyepiece, _H_, enables
one to inspect portions of the image. The two eyepieces are mounted in
a rectilinear chamber, _I_, which may be rotated about the prism at
the end of the periscope, thus bringing one or other of the eyepieces
into active position. The plan view, Fig. 4, shows in full lines the
high-powered eyepiece in operative position, while the dotted lines
indicate the parts moved about to bring the low-powered eyepiece into
use. A small catch, _J_, shown in Fig. 2, serves to hold the chamber in
either of these two positions. The high-powered eyepiece is mounted on
a plate, _K_, which may be rotated to bring the eyepiece into position
for inspecting any desired portions of the annular image. The parts
are so arranged that when the eyepiece is in its uppermost position,
as indicated by full lines in Fig. 2, the observer can see that which
is directly in front of the submarine, and when the eyepiece is in its
low position, as indicated by dotted lines, he sees objects to the
rear of the submarine. With the eyepiece at the right or at the left
he sees objects at the right or left, respectively, of the submarine.
The high-powered eyepiece is slightly inclined, so that the image may
be viewed normally and to equal advantage in all parts. Mounted above
a plain unsilvered portion of the mirror is a scale of degrees which
appears just outside of the annular image. A scale is also engraved on
the plate _K_ with a fixed pointer on the chamber, making it possible
to locate the position of any object and rotate the plate _K_ so as
to bring the eyepiece _H_ on it. The scale also makes it possible to
locate the object with respect to the boat.

[Illustration: HOW WE LOOK THROUGH A PERISCOPE

THE PERISCOPE TOP.]

[Illustration: PERISCOPE IN GENERAL USE.]

[Illustration: THE UNIVERSAL OBSERVATION LENS.]

This improved periscope is applicable not only to submarine boats but
for other purposes as well, such as photographic land surface work, in
which the entire surroundings may be recorded in a single photograph.
The accompanying photograph, taken through a periscope of this type,
shows the advantages of this arrangement and gives an idea of its value
to the submarine observer when using the low-powered eyepiece. Of
course, by using the other eyepiece any particular part of the view may
be enlarged and examined in detail.

[Illustration: INSIDE OF A MINE-PLANTING SUBMARINE

MINE-PLANTING SUBMERSIBLE.

A Lake type vessel designed for planting contact mines. In naval
warfare it is sometimes of advantage to plant mines, either to defend
harbors, or in some cases the mines are planted in the course of the
approaching enemy. This is a vessel designed for that purpose. The
enemy is seen approaching, and the mine-planting submarine runs in
ahead of them in a submerged condition and drops a number of contact
mines on their course; the enemy strikes the mine and is blown up. A
number of vessels were blown up by contact mines of this type in the
Russian-Japanese war.]


Accidents and Their Causes.

The accidents which submarine vessels must guard against are as
follows: collision, foundering, explosions and asphyxiation. The
first danger is, however, no greater than those to which vessels that
run entirely on the surface of the water are exposed. The eye of the
submarine places the commander on a practical level with the commander
of other vessels, so that if a collision occurs it is due to the same
lack of watchfulness which causes collisions on the surface of the
water.

The submarine boat is less liable to founder than an ordinary vessel,
because she is built to withstand a greater pressure of water than
other kinds of vessels. Of course, if a submarine springs a leak, she
is in grave danger of sinking to the bottom, and there is less chance
of the crew being rescued from a submarine, because no one but those on
board know of the danger if the boat is under the water.


How Explosions May Occur.

In submarine vessels explosions may occur either through a collection
of gases from the batteries or by reason of leaks in the pipes or
tanks of the fuel supply system, or through the bursting of the air
flasks belonging to the boat, or the air reservoirs in the automobile
torpedoes. The greatest danger is from explosive gases and have been
the cause of all explosions in modern submarine craft, and the greatest
danger in this connection is the liability of a leak in the gasolene
pipes or tanks. This gas is a heavy gas and so goes to the bottom of
the vessel, where it is not so easily detected as a gas which rises.
There is no certain way of guarding against leaks of gasolene. A leak
may occur at any time in a pipe or tank of gasolene through some cause
or other no matter how carefully inspected, and the gas from this is
so active that it will go through the tiniest hole imaginable--even
through a hole which water will not penetrate. The crew of a submarine
is always subject to this danger unless the tanks are built outside the
hull of the ship.


How the Air May Become Poisoned.

There is a constant danger of asphyxiation to the men in the submarine.
A very small leakage of gas or the exhaust from an internal combustion
engine may make the air so impure that those aboard will be overcome. A
great deal of care must be taken to keep the air pure and to warn the
crew at the first sign of danger from this.

When submarines first came into practical use, it was found a good idea
to take a number of little white mice down with the vessel to warn all
if the air began to become impure. As soon as this occurred, the mice
became distressed and squealed as loudly as they could, thus warning
those aboard the ship of danger. The mice felt the impurity of the air
quicker than the men, not because they had any special gift to discover
when the air was bad, but because they breathe much more quickly than
man--take shorter and many more breaths.

Now, however, a chemical device has been invented which is affected in
such a way as to ring a loud bell, if the air in the vessel becomes
impure to such an extent that there is any danger.

Breathing the same air over and over may fill the vessel with carbonic
acid gas. There should be no great danger from this, however, as
submarines are now built sufficiently large to provide enough actually
pure air for each man aboard for forty-eight hours, and it is hardly
conceivable that a submarine need be submerged more than half that
length of time under any conditions.

Of course, then, too, there is the danger of accident due to
carelessness or ignorance. In other words, it is just as difficult to
make a fool-proof submarine as a fool-proof anything else. Wherever
anything is constantly dependent upon the continuous careful attention
of human beings, there is constant danger of accident, whether it be on
board a submarine, a railroad train, steamship or in connection with
anything else.

[Illustration: A SUBMARINE UNDER THE ICE

UNDER-ICE SUBMARINE TORPEDO BOAT.

Submarine designed to navigate submerged under the ice, in ice-bound
countries. Vessels of this type could enter harbors and destroy the
enemy’s shipping at will. A vessel of this type would also be of value
in transporting mails, passengers and cargoes between ice-bound ports
where navigation by surface vessels is closed for several months in the
year.]


Story of How the Submarine Has Been Developed.

It is only within the past twenty years that man has been able to
successfully navigate under the surface of the water.

~WHO MADE THE FIRST SUBMARINE BOAT?~

It has been a dream of inventors and engineers for the past three
hundred years.

During the reign of King James I. a crude submarine vessel was built of
wood, and was designed to be propelled by oars extending out through
holes in the side of the vessel, the water being prevented from coming
in through the openings by goat skins tied about the oars and nailed
to the sides of the boat, which made a water-tight joint, but at the
same time gave flexibility to the oars, so that by feathering them on
the return stroke they could be manipulated to give head motion. Very
little, if any, success could have attended this effort.

Nearly a hundred years later a man by the name of Day built a submarine
and made a wager that he could descend to 100 yards and remain there
24 hours. He built a boat and submerged it in a place where there was
a depth of 100 yards. He succeeded in remaining the 24 hours, and
according to latest advices is still there, as he never returned to the
surface.

There is very little information as to the construction of these early
craft. The first really serious attempt at submarine navigation was
made by a Connecticut man, a Dr. David Bushnell, who lived at Saybrook
during the Revolutionary War. He built a small submarine vessel which
he called the “American Turtle,” and with it he expected to destroy the
British fleet, anchored off New York during its occupation by General
Washington and the Continental Army.

Thatcher’s Military Journal gives a description of this vessel and
describes an attempt to sink the British frigate “Eagle” of 64 guns
by attaching a torpedo to the bottom of the ship by means of a screw
manipulated from the interior of this submarine vessel.

A sergeant who operated the “Turtle” succeeded in getting under the
British vessel, but the screw which was to hold the torpedo in place
came in contact with an iron scrap, refused to enter, and the implement
of destruction floated down stream, where its clockwork mechanism
finally caused it to explode, throwing a column of water high in the
air and creating consternation among the shipping in the harbor.
Skippers were so badly frightened that they slipped their cables and
went down to Sandy Hook. General Washington complimented Dr. Bushnell
on having so nearly accomplished the destruction of the frigate.

If the performance of Bushnell’s “Turtle” was such as described, it
seems strange that our new government did not immediately take up
his ideas and make an appropriation for further experiments in the
same line. When the attack was made on the “Eagle,” Dr. Bushnell’s
brother, who was to have manned the craft, was sick, and a sergeant who
undertook the task was not sufficiently acquainted with the operation
to succeed in attaching the torpedo to the bottom of the frigate. Had
he succeeded the “Eagle” would undoubtedly have been destroyed and the
event would have added the name of another “hero” to history and might
then have changed the entire art of naval warfare. Instead of Bushnell
being encouraged in his plans, however, they were bitterly opposed by
the naval authorities. His treatment was such as finally to compel him
to leave the country, but he returned after some years of wandering,
and under an assumed name, settled in Georgia, where he spent his
remaining days practicing his profession.

Robert Fulton, the man whose genius made steam navigation a success,
was the next to turn his attention to submarine boats, and submarine
warfare by submerged mines. A large part of his life was devoted to
the solution of this problem. He went to France with his project and
interested Napoleon Bonaparte, who became his patron and who was the
means of securing sufficient funds to build a boat which was called
the “Nautilus.” With this vessel Fulton made numerous descents, and
it is reported that he covered 500 yards in a submerged run of seven
minutes.

~HOW SUBMARINES WERE DEVELOPED~

In the spring of 1801 he took the “Nautilus” to Brest, and experimented
with her for some time. He and three companions descended in the harbor
to a depth of 25 feet and remained one hour, but he found the hull
would not stand the pressure of a greater depth. They were in total
darkness during the whole time, but afterward he fitted his craft with
a glass window 1¹⁄₂ inches in diameter, through which he could see to
count the minutes on his watch. He also discovered during his trials
that the mariner’s compass pointed equally as true under water as above
it. His experiments led him to believe that he could build a submarine
vessel with which he could swim under the surface and destroy any
man-of-war afloat. When he came before the French Admiralty, however,
he was met with blunt refusal, one bluff old French admiral saying:
“Thank God, France still fights her battles on the surface, not beneath
it,” a sentiment which apparently has changed since those days, as
France now has a large fleet of submarines. After several years of
unsuccessful efforts in France to get his plans adopted, Fulton finally
went over to England and interested William Pitt, then chancellor,
in his schemes. He built a boat there, and succeeded in attaching a
torpedo beneath a condemned brig provided for the purpose, blowing her
up in the presence of an immense throng. Pitt induced Fulton to sell
his boat to the English government and not bring it to the attention of
any other nation, thus recognizing the fact that if this type of vessel
should be made entirely successful, England would lose her supremacy as
the “Mistress of the Seas.”

Fulton consented to do so, but would not pledge himself regarding his
own country, stating that if his country should become engaged in war,
no pledge could be given that would prevent him from offering his
services in any way which would be for its benefit.

The English Government paid him $75,000 for this concession. Fulton
then returned to New York and built the “Clermont” and other
steamboats, but did not entirely give up his ideas of submarine
navigation, and at the time of his death was at work on plans for a
much larger boat.

Fulton had a true conception of the result of submarine warfare, and in
a letter he says: “Gunpowder has within the last three hundred years
totally changed the art of war, and all my reflections have led me to
believe that this application of it will, in a few years, put a stop
to maritime wars, give that liberty on the seas which has been long
and anxiously desired by every good man, and secure to Americans that
liberty of commerce, tranquillity, and independence which will enable
citizens to apply their mental and corporeal facilities to useful and
humane pursuits, to the improvement of our country and the happiness of
the whole people.”

After Fulton’s death spasmodic attempts were made by various inventors
looking to the solving of the difficult problem, but no very serious
efforts were put forth until the period of the Civil War, and then a
number of submarine boats were built by the Confederates. These boats
were commonly called “Davids,” and it was one of them that sank the
United States steamship “Housatonic” in Charleston Harbor on the night
of the 17th of February, 1864. This submarine vessel drowned four
different crews, a total of thirty men, during her brief career. At the
time she sank the “Housatonic” her attack was anticipated, and sharp
lookout was kept at all times; but, notwithstanding their vigilance,
she succeeded in getting sufficiently close to plant a torpedo on the
end of a spar, and sink this fine, new ship of 1400 tons displacement.

It will be seen from the above description that these vessels, while
able to go under water, were not controllable.

After the Civil War several other inventors took up the problem of
trying to design a submarine vessel that could be controlled as to
maintenance of depth and direction under water.

In Europe, Gustave Zede, Goubet and Drzwiezki, and in this country Mr.
Baker and Mr. John P. Holland, built experimental vessels.

In 1877 Mr. Holland built a small boat which was called the “Fenian
Ram.” It is stated that this vessel was built with capital furnished by
the “Clan-na-Gael,” with the idea of using it against the British fleet
in an attempt to free Ireland.

While some slight success was met with by these inventors, it was not
until about 1897 that any real progress was made.

~THE FIRST SUCCESSFUL SUBMARINE WITH HYDROPLANES~

In 1893, Simon Lake, an American inventor, submitted plans to the
United States Naval authorities at Washington for a submarine boat that
would navigate between the surface and the bottom by the use of what
he called “hydroplanes,” which were designed to cause the vessel to
submerge on an even keel. Mr. Lake’s design of vessel was also provided
with wheels to enable it to navigate on the water bed. It was also
provided with a diving compartment to enable the crew to don diving
suits and leave the vessel, in working on wrecks, cutting cables,
planting mines, etc.

In 1904 and 1905 he built a small vessel to demonstrate his principles
and succeeded in successfully navigating the vessel on the bottom
of New York Bay. He then built a larger vessel of about 50 tons
displacement for further experimental purposes. This vessel was called
the “Argonaut,” and was built in Baltimore in 1906 and 1907. This boat
was successful from the start and covered thousands of miles in the
Chesapeake Bay and along the Atlantic Coast, New York Bay and Long
Island Sound, and was the first successful submarine boat to navigate
in the open sea and on the water bed of the ocean.

Mr. Holland had, in 1894, received a contract for a submarine vessel
for the United States Navy, and her construction was started in 1895.
This vessel was called the “Plunger.” This was the first official
recognition given to a submarine boat in the United States.

The Government of France had also given an order for a submarine boat
which was under construction at this period.

The “Plunger” was never submerged, her construction covering a period
of several years, and she was finally abandoned. Mr. Holland had,
however, in the meantime prepared the designs of another vessel which
he called “The Holland.” This vessel was accepted by the United States
Government in 1900, and a number of other vessels of this type were
built. These vessels were known as submarines of the diving type. They
were controlled by means of a horizontal and vertical rudder placed at
the stern of the vessel and the boat was, by means of these rudders,
inclined down by the bow, and driven under the water by the force of
their screw propeller.

England also built a number of submarines of the diving type.

In 1901 Mr. Lake brought out a larger vessel of his type, which was
controlled by hydroplanes, which vessel was sold to the Russian
Government, was shipped across the Atlantic to Kronstadt, and from
there by rail to Vladivostok, and was in commission off Vladivostok
just before the close of the Russian-Japanese War.

Mr. Lake then received orders from the Russian and other Governments
for a number of additional boats of the even keel type, to be
controlled by hydroplanes.

Mr. Lake’s principles of control have been now generally adopted by all
Governments, as providing the safest and most reliable means of control
of the vessel when navigating under the surface.

The United States Government has recently adopted this type to be
built in their Navy Yards, and most other builders have adopted the
hydroplanes as the means of maintaining depth when running beneath the
surface.

[Illustration: CLEARING A CHANNEL OF BUOYANT MINES

This is one of the services to which submarine boats of this type lend
themselves with peculiar fitness. It is possible for them to carry on
this work with deliberation and to success, under the very guns and
searchlights of a vigilant foe, without the slightest danger of being
detected.

This would be accomplished preferably by the co-operation of two boats.
They would take opposite sides in the channel, with a connecting rope
extending out through the diving compartment. It is obvious that as
they move along the rope will sweep the whole mine-field and gather in
the connecting cables. This would be indicated at once to the operators
in the diving compartment by the load upon the sweeping line. A grapple
may then be attached to the rope and sent out of one boat and hauled
into the other, and thus drag the mine so near that a diver could go
out and destroy its electrical connections or cut it adrift. Should
the latter operation be the aim, the grapple may be so fashioned as
to accomplish this without the diver leaving the compartment. This
latter method is one strongly recommended by some of the most prominent
military authorities on submarine defense.]

[Illustration: This picture indicates the manner in which the boats
have traveled many miles over all kinds of bottom. In the present
instance the boat is shown systematically searching the bottom with
her diving door open and strong lights being used to facilitate a more
perfect examination.

There is no trim or equilibrium to maintain. When the propelling
machinery stops the boat comes to rest. A cyclometer attached to
these wheels gives a fairly reliable reading of the distance traveled
under normal circumstances. As the currents do not carry her out of
her course, and as her gauges give an absolute record of changing
depths, it is possible to so navigate upon the bottom with remarkable
precision. In shallow waters this method has many advantages.]

[Illustration: A MACHINE WHICH MAKES THE DIVER’S TASK EASY

SHOWING TUBE HANDLING CARGO IN SUNKEN SHIP.]


Recovering Cargo or Submerged Objects Without the Aid of Divers.

The operating tube is here shown within the body of a hulk and
co-operating with the lifting derrick on the surface craft in the
removal of the submerged cargo. A grab-dredge bucket of well-known
construction is used, the jaws of which, when being lowered by one
rope, open, and when strain is brought on the lifting rope, the
jaws close. The working end of the tube is placed in the immediate
neighborhood of the cargo to be lifted and, as the grab is being
lowered from the boat above, the operator in the compartment controls
the grab by means of the guide line shown attached to the small derrick
boom, and leads it directly over the cargo to be lifted. The grab is
then dropped and the signal sent to the vessel above to hoist. The
moment the lifting line tautens the bucket grasps a load and fills
itself with material in the manner common to this type of dredge. This
method of directing intelligently and deliberately the dredge bucket
may be applied as well to the removal of rock or any other obstruction
or to any of those various services of kindred character familiar
to submarine engineers. The great and prime advantage of the system
is the fact that no divers are required, and the work is under the
perfect control of an operator subject only to atmospheric pressure. In
consequence, therefore, the only limit to the effective operating of
this apparatus is the length of the tube, and, as has been said, this
can be made long enough to reach depths denied to the diver simply by
interposing additional sections.

[Illustration: LIFE ABOARD A SUBMARINE

LIVING QUARTERS ABOARD A SUBMARINE.]




Where Do Sponges Come From?


Until within comparatively recent years, the sponge was regarded as
a plant; it is now known to belong to the animal kingdom, and to the
order spongida of the class of rhizopoda. Sponge is an elastic, porous
substance, formed of interlaced horny fibers, which produce by their
numerous inosculations, a rude sort of network, with meshes or pores
of unequal sizes, and usually of a square or angulated shape. Besides
these pores there are some circular holes of large size scattered
over the surface of most sponges, which lead into sinuous canals that
permeate their interior in every direction. The oscula, canals, and
pores, communicate freely together. The characteristic property of the
sponge is the facility with which it absorbs a large quantity of any
fluid, more especially of water, which is retained amid the meshes
until forced out again by a sufficient degree of compression, when the
sponge returns to its former bulk. From this peculiarity, combined with
its pleasant softness, arises the value of the sponge for the purposes
to which it is applied. In domestic economy and in surgical practice,
there is no other product that can be satisfactorily substituted for it.

Sponge is an aquatic production, indigenous to almost every sea and
shore. It is abundant and varied between the tropics, but becomes
less so in temperate latitudes and continues to diminish in quantity,
variety, and size, as it is traced into European and colder seas, until
it almost disappears in the vicinity of the polar circles. Some sponges
are known to be hermaphrodite, but that the individual at one period
produces chiefly male elements, and later, chiefly female elements.
Fertilization takes place in the body of the mother, and the egg here
undergoes its early development. The embryo eventually bursts the
maternal tissue and, passing into one of the canals, is caught by the
current sweeping through the canal system and is discharged into the
surrounding water through one of the large apertures on the surface
of the sponge. In the Bahama Islands and along the coast of Florida,
the breeding time of many sponges covers the period from mid-summer on
through early Autumn.

There is propagation sometimes by ciliated gemmules, yellowish and
oval, arising from the sarcode mass, and carried out by the currents.
These are mostly formed in the spring, and after swimming freely about
for a time, become fixed and grow. In its natural state, the sponge
is a very different looking object from the article of commerce. The
entire surface is covered with a thin, slimy skin, usually of a dark
color, and perforated to correspond with the apertures of the canals.
The sponge of commerce is in reality only the home or the skeleton of
the sponge.

There are a few sponges that inhabit ponds and sluggish rivers; the
others are marine. Of these, many of the calcareous and siliceous kinds
inhabit the shores between tide-marks, preferring a site near the low
ebb, where, nevertheless, they are daily alternately submerged, and
left exposed to the atmosphere. The figured sponges with a fibrous
texture, to whatever genus they belong, are denizens of deeper water,
and are never left uncovered. They grow usually in groups, on rock
shells, shellfish, corallines, and seaweeds, and either have no power
of selection, or the quality of the site is indifferent to them.




How Do Sponges Grow?


In their growth, some sponges assume a determinate figure or at least
one whose variations are confined within certain limits. The greater
number are irregular and variable, their shape depending in a great
measure upon the peculiarities of their state, to which they easily
accommodate themselves. They will incrust a shell, or a crab, a rock,
or seaweed, following every projection and sinuosity. The offshoots
will spring up with a more luxuriant growth in the deeper sheltered
places until the original shape of the foundation they grow upon is
lost to sight.

Sponges are unmoving and inirritable. They never remain rooted to the
places of the germination, and are incapable either of contracting or
dilating themselves or even of moving any fiber or portion of their
mass. The functions which distinguish them as living beings are few,
and faintly imaged.




How Do Sponges Eat?


Although sponges lack the power of motion possessed by most animals,
being nearly always attached, in one position or another, to some
object, the study of their habits in captivity brings out many of their
animal characteristics in a striking manner. Small specimens taken
from the sea and placed in dishes of salt water may be kept alive for
several hours if well cared for; and by using finely powdered coloring
matter, such as carmine or indigo, the manner of their feeding may be
readily observed. Sponges are more active in fresh sea water than in
stale; they cannot be kept alive out of water and soon die if exposed
to the air. Being unable to go in search of food, as a natural result,
they can grow only in places where there is always an abundance of
food suited to their wants. The great sponging grounds of the world
are wholly confined within waters having a relatively high temperature
during the entire year. The Old World sponges grow principally in
the Mediterranean and the Red seas; the New World sponges are found
about the Bahamas, southern and western Florida, and parts of the West
Indies. The finest sponges come from the East, but one of the American
species, the so-called “sheep’s wool,” stands high in favor.

The commercial sponges are separated into six species, three of which
are European and three American. They are all referred to a single
genus called spongia, and though having much in common as regards
structure, their texture varies to such an extent as to make them of
very unequal value for domestic purposes.

The Old World species may be arranged as follows, in order of their
grade of excellence, beginning with the best quality: The Turkey cup
sponge, Levant toilet sponge, the horse, honey comb, or bath sponge,
and the Zimoca sponge. The American species include the sheep’s wool
sponge, the yellow glove, violet, and grass, sponges. A very close
relationship exists between the species of the two continents.

All known regions in which useful specimens abound contribute to the
world’s supply. The trade is extensive. The demands upon the fisheries
are great. In the Mediterranean, the fishing is carried on in some
places at a depth of forty fathoms. Divers, naked, or in armor, go down
to the bottom and tear off the sponges from their places of growth. In
some places drag dredges are employed.




How Are Sponges Caught?


In the past quarter-century the sponge-fishery of the Florida coast has
grown remarkably. Its headquarters is at Key West and several hundred
sailing vessels are engaged in the industry. The fishing appliances
consist of a small boat, a long hook, and a waterglass. The hook is
in reality a three-pronged spear attached to a pole thirty-five feet
long. In searching for sponge the fishers row about in the small
boat. By holding the glass on the surface of the water the bottom is
plainly seen and small objects are readily discerned. When a sponge is
sighted the pole with the hook attached is shot down and the product
deftly gathered. The boat-load is brought to the deck of the schooner,
allowed to remain there a few hours, and then is carried down into the
hold. On Friday nights, the fishing generally ends for the week, and
the vessel sails for some spot on the neighboring coast where there
are established crawls, or places for curing the catch. These crawls
are about 8 x 10 feet square, their purpose being to hold the sponges
while maceration and decomposition take place. The resulting refuse is
carried off by the tide.

The fishermen go away for another catch and the sponges are left in the
crawls until the end of the following week when a new cargo is brought
in. The returning fishermen beat the decomposed sponges with clubs,
removing the impurities. The water is squeezed out, then the sponges
are allowed to dry on the ground.

After drying, the hold of the large vessel is loaded to the utmost
with the product and the voyage to Key West is made. Buyers from New
York look over the sponges, and make offers for entire cargoes. The
fishermen dispose of their goods rapidly and sail away for more. The
buyers store the sponges in some dry building, and cause them to be
bleached by lime. A popular manner of bleaching is to wash the sponges
thoroughly in water, and then to immerse them in diluted hydrochloric
acid to dissolve any of the calcareous substance. Having again been
washed they are placed in another bath of dilute hydrochloric acid to
which six per cent. of hyposulphite of soda, dissolved in a little warm
water, has been added. In this bath the sponges remain for twenty-four
hours, or until the bleaching process is completed. After bleaching,
the sponges are pressed until their bulk is greatly reduced; they are
then baled, and shipped to New York, which is the distributing point
for the entire Florida product.

Sponges are by far the most important fishery products of Florida,
representing about one-third of the annual value of the fishing
industry. In 1899, the yield was over 350,000 pounds of sponges of
which the first value was nearly $400,000.




Why Does Yeast Make Bread Rise?


There is a lot of sugar in the dough from which bread is made. Sugar
contains three things--carbon, hydrogen and oxygen. When sugar is
fermented it amounts practically to burning it. To make good bread
from the dough it is necessary to ferment the sugar which is in the
ingredients from which it is made. Yeast, which is a simple living
plant, has the power to ferment sugar. When sugar ferments, two things
are produced. One thing is the formation of carbonic acid gas. A great
deal of this carbonic acid gas is caught in the dough in the form of
large or small bubbles and some of it escapes into the air. The other
part tries to escape into the air also but cannot, and causes the dough
to rise, which makes the bread light, as we say. The holes you see in
the bread after it is baked are the little pockets where the carbonic
acid gas was retained in the dough. These bubbles of gas all through
the dough act like a lot of little balloons and lift the dough up with
themselves as they try to get to the top and escape into the air.




What Is Yeast?


Yeast is a living plant that is used for the purpose of causing
fermentation. The yeast we use in baking bread is an artificial
yeast--really a dough made of flour and a little common yeast and made
into small cakes and dried. If kept free from moisture it retains the
power of causing fermentation for some time. The flour and other matter
in a cake of yeast are only used to keep the yeast in a form where it
can be preserved. It is necessary to add water to start fermentation
and that is why we add hot water when we stir in the yeast for a baking.




Is a Moth Attracted By a Light?


It seems to be a strange contradiction of the nature of living things
that a moth should fly deliberately into a light or dash itself to
death against the glass surrounding a strong light. This is contrary
to the usual law of nature which gives the living thing an instinct to
protect itself against enemies.

For a long time we thought that moths did not deliberately burn
themselves up by flying right into a light, but our naturalists
have proven that not only moths but certain birds, bees, flies and
butterflies, burn themselves up by flying into the flame of a light or
fire.

[Illustration: HOW MAN LEARNED TO MAKE A FIRE

SAWING

This was probably man’s first method of producing fire. By rubbing two
sticks together in this way sufficient heat was produced to set fire to
easily burnable material such as dried grass, etc.]

[Illustration: DRILLING

An improvement came when man learned that by twirling a dry stick in
a hole in another piece of dry wood the fire could be started more
quickly.]




How Man Discovered Fire


Fire was probably one of man’s first, if not the first, great
discoveries, and has been one of his greatest servants as well as
one of his greatest dangers. We do not know who discovered fire, or
what nation first used it. It is, however, one of the signs that
distinguishes man from the other animals. Not any of the lower animals
was acquainted with the use of fire, while probably the earliest races
of mankind seem to have been acquainted with it.

Mythology tells us wonderful stories of the origin of fire: according
to these tales it was stolen from the sun, or the gods, and given to
man; and Pandora, the first woman, was sent down to earth to punish man
for his theft.

The most popular of these stories is the legend of Prometheus.
According to this legend, fire, in the early days, was under the
exclusive control of the gods. Prometheus, brother of Atlas, the god
who supported the world on his shoulders, determined that the use of
fire should be given to the people. He decided by some means to send
a spark of fire to the earth, believing that one spark caught by man
would start a burning flame that would never go out.

With this idea in mind, Prometheus visited Zeus, the great ruler, to
carry out his purpose, for Zeus controlled fire. While Zeus was not
looking, Prometheus “stole some brands of fire from the hearth, which
he hid in the stalk of a fennel and sent it down to the earth.” Through
this Prometheus gave to man his first knowledge of fire.

But while this story of fire may or may not be true, the use of fire
rests entirely with man and his ingenuity. Through his ingenuity man
was able to subject fire to his will; making it perform certain of his
labors; and to a certain extent making it his servant; although it
always did and always will get beyond his control at times.

Our ancestors were not satisfied with preserving the fire which the
gods gave them; they tried and succeeded in producing it. One day one
of them discovered that by rubbing two sticks together rapidly, the
friction would create a fire. It was a most useful discovery. Before
long the whole of mankind had learned this trick; others improved on
this crude method until step by step men learned that by striking two
pieces of flint or other hard mineral together, quicker action was
obtained.

[Illustration: DRILLING WITH BOW STRING

Man’s ingenuity soon taught him that if he tied one end of a string to
something and wrapped it around his drilling stick, one end of which
was in a hole as in the first drilling picture, he could increase the
rapidity of making fire.]

[Illustration: DRILLING WITH HELP

With some other to hold the drilling stick while he operated the string
he was able to produce fire more quickly than he had ever done before.]

All kinds of methods were devised to increase knowledge of producing
fire. The early Greeks found out how to catch the rays of the sun on a
burning-glass and produce fire; the Romans achieved the same results
through the use of mirrors.

[Illustration: PLOWING

This is another method man used for rubbing two pieces of wood
together. In following this plan he usually used one stick of bamboo
and rubbed it back and forth in a slot he had made in another piece of
bamboo.]

[Illustration: FLINT AND PYRITES

In some places it was discovered that if you struck a piece of hard
stone, like flint, against another, a spark was produced which could be
caught on a bunch of dry grass or moss and so start a fire.]

In about A.D. 900, an Arab, named Bechel, discovered phosphorus, but it
took almost 800 years more for Haukwitz to learn that when phosphorus
was brought into friction with sulphur, fire would result. In another
hundred years the world was benefited by the invention of the friction
match--and since that time about one-half the people have been carrying
matches about with them, able thus to start a fire easily any time.

~FIRE A MARK OF CIVILIZATION~

Fire and man’s knowledge of it have had much to do with man’s progress
in civilization. Before man had fire, his life and movements were much
like those of other animals. When man had learned to make a fire he was
free to move and live anywhere and, therefore, people began to cover
more territory.

[Illustration: THE FLINT AND STEEL METHOD OF MAKING FIRE

THE INTRODUCTION OF THE FLINT AND STEEL METHOD

Because fire was so important to him, man kept on trying to make this
task easier. He finally contrived a tinder box when iron and steel
became known. The tinder box is where he kept his flint and the piece
of steel which he struck upon the flint. He also kept in the box pieces
of cloth or paper on which he caught the sparks so produced.]

[Illustration: PISTOL TINDER BOX

This is a picture of a tinder box in the form of a pistol. It enabled
man to produce sparks in greater numbers and more rapidly.]

[Illustration: PRODUCING SPARK WITH FLINT AND STEEL

This shows the method for striking the piece of steel against the flint
to make the sparks fall on the cloth or paper in the box.]

[Illustration: A COMPLETE TINDER BOX SET

This picture shows a very complete tinder box set used by the wealthy
people in the old days. A man carried this outfit with him just as
today he carries matches.]

[Illustration: This tinder box set is very neat and compact. It is said
still to be used among the Himalayan tribes where it was discovered.]

[Illustration: THE FIRST MATCHES

THE OXYMURIATE MATCH

This match, the first, was introduced in 1505. It was a slip of wood
tipped with a chemical mixture. To light it it was necessary to stick
its head into a bottle containing acid.]

[Illustration: PROMETHEAN MATCH

This was a paper cigarette dipped in a mixture of sugar and potash.
Rolled within the paper was a tiny glass bulb filled with sulphuric
acid. To light the match you pressed the bulb with pincers hard enough
to break the bulb. This released the acid which set fire to the paper.]


What Would We Do Without Matches?

If one were to ask the man in the street what invention of the
nineteenth century is his most constant and invaluable ally he might be
mystified for the moment, but the undoubted answer would surely come
in the single word “Matches.” These familiar objects, apart from their
luxurious use by smokers, are the indispensable servants of mankind
from the moment of rising in the morning till the household is wrapped
in sleep, and it is to them we turn when disturbed in the hours of
darkness.

[Illustration: FIRST LUCIFER MATCH

Invented by John Walker in 1827. It consisted of a stick of wood tipped
with sulphur and then with a chlorate mixture. To ignite it the match
was drawn rapidly through a folded piece of sandpaper.]

[Illustration: MODERN SAFETY MATCH

The first practical match was made less than a century ago.]

No doubt “familiarity breeds contempt,” and it is difficult to imagine
how man would fare, bereft of his box of matches. It might help the
world to realize how much it owes to the inventors of the Lucifer
Match, were it possible to cut off the supply of these magic fire
producers for only one brief day. It requires no very vivid imagination
to picture the consternation and confusion that such a step would
produce, and there is a grim humor in wondering how the primitive
methods of obtaining a light would serve the public convenience in
these days of strenuous hustle.

Seeing that fire has been employed by man since prehistoric days, one
would expect that easy means of obtaining it would have been devised
in the early ages. We find, however, that until the beginning of the
nineteenth century nothing in the nature of a match was available, and
the crudest methods were still in use. We know from Virgil that in the
reign of the Emperor Titus fire was obtained by rubbing decayed wood
with a roll of sulphur between two stones, but it is not till Saxon
times that we have evidence of the use of the tinder box with its flint
and steel. That this latter was still regarded as something remarkable,
as late as the fifteenth century, is proved by its representation in
the collar of the Order of the Golden Fleece, which was founded in
1429. Burning glasses had, of course, been employed from the most
primitive times, but one can imagine the despair of an early Briton who
had to wait for a sunny day before he could boil his kettle.

Incredible as it may seem, it was not a time well within the memory
of many people living to-day that matches in anything approaching
the form now familiar were offered to the public. The way for their
manufacture had been prepared by two discoveries; one by a German who
isolated phosphorus in 1669; the other by a Frenchman who produced
chlorate of potash in 1786. From this latter date the production of
fire was much facilitated, and a few years before Queen Victoria came
to the throne, John Walker--a chemist of Stockton-on-Tees--produced the
first friction matches of which there is any certain record. These,
called “Congreves,” were sold in boxes of fifty for 2/6, and their
success soon led others to experiment in match manufacture, so that
improvements were rapidly invented and factories sprang up in all parts
of the country.

It would be a difficult task to compute accurately the value to the
human race of the introduction to general use of this little article.
At the present writing, in America the consumption of matches amounts
to over a billion of matches a day.


How Matches Are Made.

To-day matches are in such demand that the ingenuity of man has devised
a machine which makes complete matches without the help of the human
hand.

At the very start of operations a man feeds blocks of wood into the
jaws of the machine, and thenceforth the mechanical monster does its
own work. Seizing the block from the man’s hand, the machine grips it
between rollers and forces it against rows of keen-edged cutters, which
are so arranged that there is little or no waste. Each of these cutters
(and there are usually forty-eight in a machine) severs a piece of wood
of exact size and shape. At the same moment a plate rises from beneath,
which thrusts these little pieces of wood into a moving flexible
cast-iron band, or rather into small holes in this band, from which the
embryo matches project like bristles. This traveling band is about 700
feet in length, and follows a serpentine course in its journey, which
occupies about an hour from start to finish, the speed being regulated
according to temperature so that the matches may be quite dry when they
reach the boxes.

When the band arrives at the finishing point, a steel bar punches out
the matches stuck in its surface and they fall into the inside boxes
placed ready to catch them. These boxes are kept continually shaking,
to that no spaces are left and the matches fill them completely. As the
inside boxes fill, a steel arm presses them forward into their covers,
and they are passed along a trough in dozens, quickly wrapped in paper
and sealed by a machine. Quick-fingered girls then wrap twelve of these
dozen packages and we have the gross packages of boxes so familiar in
the stores. It will be seen, that in spite of the marvellous machines
which do so much, there is still plenty of work for human hands.


How Match Boxes Are Made.

The machines for making the wooden box which contain the matches are
in themselves wonderful. First, a section of the trunk of an aspen
tree, about 30 inches in length, is made to revolve in what is known
as a peeling machine. After a few revolutions the rough outer surface
is removed, and thin rolls of smooth-surfaced wood are peeled off
or veneered. The machine at the same time scores the wood ready for
folding by the boxmaking machine. Cut into skillets, i. e., into pieces
of the size required for box covers or insides, the ends are next
dipped in pink dye to cover the edge of the wood which is not covered
by the label. The skillets then go to the box machines, which fold and
label them, and after half an hour in a cleverly devised drying chamber
they are ready for use. In one room alone sixty machines are labelling
and folding the skillets to the number of several thousand gross a day.
To see these machines take a strip of wood, push it forward to receive
the pasted label, fold it, fasten the joint, wipe off the superfluous
paste, and, finally, toss the finished “outside” into a receiving
basket, is as fascinating an example of mechanical ingenuity as the
industrial world can afford.


Are Matches Poisonous?

A non-poisonous “strike anywhere” safety match, made from selected,
clear, strong cork pine is now made in this country, and is the first
satisfactory non-poisonous match. It is also the first match to be
endorsed by the country’s recognized leaders and authorities in fire
prevention and the conservation of human life and property.

The Hughes-Esch Anti-White Phosphorus Match Bill, which became a
law during the administration of President Taft, was drafted by the
attorneys of the American Association of Labor Legislation, and is
the most drastic that our National Constitution will permit. It would
be unconstitutional to absolutely prohibit the manufacture of white
phosphorus matches, but the Hughes-Esch bill obtains the same result,
viz.: absolute prohibition by means of excessive taxation. No match
manufacturer in these days of keen competition can afford to pay a tax
of ten cents on each box of white phosphorus matches made, and place
his factory under government surveillance, for this tax of ten cents is
over three times as much as his present selling price to the wholesale
trade.

As soon as man learned to make fire and light, he began to appreciate
how much more comfortable he could be if he could keep his lights
burning and to have his light independent of his fire, because it was
at times very uncomfortable to sit by a fire on a hot night simply
because he wished to use the light which it made. The first schemes
devised for lighting purposes merely were the camp-fire torch and the
rushlight. With these as a basis, man was enabled to fashion more
convenient forms of lighting. He invented the candle and the lamp, and
grown “enlightened,” boxed his light in iron and in other metals.




Did Candles Come Before Lamps?


The candle is in appearance a primitive affair, yet there is little
doubt that its predecessor was the lamp. Those old Egyptian tombs,
which have unlocked many mysteries, held lamps, and through them
evidence of ancient burial customs. Lamps played a part in the solemn
feasts of the Egyptians, who on such occasions placed them before their
houses, burning them throughout the night. Herodotus, in one of his
numerous references to Xerxes, alludes to the hour of lamp-lighting,
and evidences abound regarding the use of lamps among the ancient
Greeks. Lamps, indeed, are pictured upon some of their oldest vases,
indicating the symbolic significance which attached to them.

[Illustration: A French watch tower of the fifteenth century in time
of siege. The tower is lighted by means of beacons and is protected by
dogs. Ruins of such a tower can still be seen at Godesberger on the
Rhine.]




What Were the Earliest Lamps?


It is probable that the earliest lamps were nothing more than
convenient vessels, filled with oil and fired by means of rushes. Among
the Romans pine splinters, the torch and the flambeau, supplied light
until the fifth century before Christ, and even when the Roman began to
use the lamp, it was by no means common, finding a place only in the
homes of the rich, or on special festival days.

The custom of burning funeral lights beside the dead before interment
is a very old one. Gregory, interpreting its significance for the
Christian, says that departed souls, having walked here as the children
of light, now walk with God in the light of the living. The Roman,
Pliny, refers to the use of the pith of brittle rushes in making
funeral lights and watch-candles, which were probably the ancient
prototype of the old rushlight of England. Again, in speaking of flax,
Pliny states that the part of the reed that is nearest to the outer
skin is called tow, and is good for nothing but to make lamp-matches or
candlewicks.




What Were the Lamps of the Wise and Foolish Maidens Made Of?


When lamps had come into general favor, better attention was given
to their form and construction. The first seem to have been made of
baked clay, moulded by hand into elongated vessels to contain the oil,
and provided at one end with a lip to admit the wick. These are the
lamps which artists have pictured in the hands of the wise and foolish
virgins, though in the opinion of some scholars they were merely rods
of porcelain and iron, covered with cloth and steeped in oil. Another
early type, which was less common, presents a simple disc with an
aperture in the centre for the oil, and a hole for the wick, at one or
both of the sides.

Under the Empire, when the light of the lamp had become general, the
better ones were made of bronze, ornamented with heads, animals, and
other decorations, attached to the handles, while as life in Rome
partook more of luxury and extravagance, gold, silver, or Corinthian
brass were the materials, the designs being more elaborate and
complicated. Many and beautiful examples of these ancient lamps have
been unearthed from the ruins of Herculaneum and Pompeii.




When Were Street Lamps First Used?


Dark must have been the lives of those people who, until comparatively
recent times, lived, in the absence of sunlight, by the feeble,
uncertain light of the primitive illuminants borne by these lamps. And
as for street lighting--that was a luxury but seldom indulged in, and
then, not for public benefit, but to enhance the glory of a potentate,
or grace the obsequies of some great man. Even Rome, at the height of
her luxury and beauty, rarely exhibited more than one or two lanterns
in her streets. These were suspended over the baths and places of
public resort. Occasionally, however, the streets were illuminated
during festivals and other public occasions, while the Forum was
sometimes lighted for a midnight exhibition. With these glittering
exceptions, and that memorable one when, to satisfy the homicidal
impulses of a bad emperor, the bodies of Christians were made living
torches, Rome was a city of darkness.

[Illustration: THE FIRST STREET LIGHT IN AMERICA

The first street light in America. Early in 1795 several large cressets
were placed on the corners of Boston’s most frequented street.
Pine-knots were placed in these fire baskets by the night watchman.]




When Were Candles Introduced?


Historical records indicate the prevalent use of candles in the
earliest days of Rome, but these candles were of the simplest
sort--mere string or rope which had been smeared with pitch or wax.
In the early Christian centuries it was the custom to dip rushes in
pitch and coat them with wax, a method of candle-making that was long
continued, for it was not until the fourteenth century that dipped
tallow candles were introduced. In the Middle Ages wax candles provided
the usual means of illumination, and these were made, not by common
craftsmen, but by monks, or by the servants of the rich. Until the
fifteenth century their use was confined to churches, monasteries and
the houses of nobles, but the demand for them had become so great that
the chandlers of London obtained an act of incorporation. As late as
the eighteenth century the candles were made by dipping the wicks
into melted wax or tallow, but about this time an ingenious Frenchman
conceived the idea of casting them in metal moulds.

[Illustration: A part of the “Amende Honorable” of Jacques Coeur before
Charles VII of France.]

[Illustration: A pagan votive lamp of bronze, now in the museum at
Naples.]

It is only within a modern period that the state or city has assumed
responsibility in the matter of public lighting, which for the most
part had been left to the good will and public spirit of citizens.
But in England a proclamation was issued to the effect that every
individual should place a candle in each of the lower windows of his
house, and keep it burning from nightfall until midnight.

[Illustration: THE FIRST OIL LANTERN

The first “Réverbère”--oil lantern--with a metal reflector, used
to light the streets of Paris. It was invented by Bourgeois de
Châteaublanc in 1765, and used until the introduction of gas.]

Paris was the first city to improve upon this method of street
lighting, and in 1658 huge, vase-like contrivances, filled with resin
and pitch, were set up in the principal thoroughfares. The improvement
proving, as may readily be seen, both dangerous and expensive, the
falct, so-called, were replaced by the lantern. This was at first
simply a rude frame, covered with horn or leather, within which a
candle burned. For more than one hundred years this was the extent of
the illumination which the authorities could provide. But of course
it was understood that no honest man would venture abroad without his
torch or flambeau, and as London, Berlin, Vienna, and all leading
cities of Europe, were in like case, the darkness of Paris could be
borne.

[Illustration: Argand got his first suggestion for his burner--invented
in 1780--from this style of alcohol lamp, then in general use
throughout France.]

But progress had been made, and early in the eighteenth century the
Corporation of London entered into contract with a certain individual
to set up public lights, giving him permission to exact a sum of six
shillings from every householder whose actual rent exceeded ten pounds.
In the middle of the same century the Lord Mayor and Common Council
applied to Parliament for power to light the streets of London better.
From the granting of this permission dates improvement in public
lighting.




Where Did the Word “Gas” Originate?


A Belgium chemist, Van Helmont, coined the word “gas” in the first half
of the seventeenth century. The Dutch word “geest,” signifying “ghost,”
suggested the term to him, and his superstitious neighbors hounded him
into obscurity for talking of ghosts.

[Illustration: Hanging lamp from Nushagak in Southern Alaska. It is
suspended from the framework of the tent by cords. Oils and fats from
northern animals give a clear and steady light, and Eskimo lamps are
frequently praised by travelers.]

[Illustration: WHAT THE BIG TANK NEAR THE GASWORKS IS FOR

SIX MILLION CUBIC FOOT GAS HOLDER.

Almost every boy and girl has seen the big tank near the gas works, and
most of them have wondered what was in it and what it is for. This big
tank is a “holder” in which the gas is stored after it is manufactured.

The giant holders are reservoirs from which gas is constantly being
taken and the quantity on storage constantly replenished, as the
ordinary gas plant never ceases manufacturing its product.

There is little or no danger of an interruption of the supply by reason
of accident, as gas plants are always equipped with duplicate apparatus
for emergencies.]


When Illuminating Gas Was Discovered.

The first practical demonstration of the value of gas made from
coal for lighting was made by a Scotchman--Robert Murdock--who in
1797, after some years of experimenting, fitted up an apparatus in
the workshop of Boulton and Watt, in Birmingham, England, which
successfully lighted a portion of that establishment. The advantages
of this kind of lighting were so apparent that its use was rapidly
extended, although in many instances the people were afraid of it. For
a time this kind of lighting was confined to street lights. One of the
first great structures to be lighted by gas was Westminster Bridge in
London, and great crowds gathered to watch the burning jets nightly. It
was difficult to remove from the minds of the people the belief that
the gas-pipes were filled with fire and the jets were only openings
through which the flame in the pipes escaped. People sometimes touched
the pipes expecting to find them hot, and when the pipes were put in
buildings they made sure that they were placed several feet from the
walls lest the fire in them set fire to the buildings.

The use of illuminating gas for lighting private houses developed quite
slowly because of this fear of the fire in the gas-pipes. This was not
entirely unwarranted, however, because at first the plumbers did not
know, as they do now, how to prevent leakage of gas from the pipes.
The methods of joining the pipes were oftentimes imperfect and, not
realizing the dangers which would follow leaks, causing explosions, the
workmen were often careless in installing the pipes.

The first American house in which gas was used for lighting was the
home of David Mellville at Newport, R. I. Baltimore, Maryland, was the
first American city to use gas for lighting. It was introduced there in
1817.


How Does Gas Get Into the Gas Jet?

If you hold a cool drinking glass over a burning gas jet for a moment,
a film of moisture will form on the inside of the glass and remain
until the tumbler becomes warm, and then disappear. Now, then, you will
remember that water is a mixture of oxygen and hydrogen, and that when
hydrogen is burned in the air, water is formed. It is also true that
whenever water is formed by burning anything, hydrogen is present in
it. You see, therefore, that the gas used for lighting purposes must
contain hydrogen.

Let us now learn something more about what gas is made of. Wet a piece
of glass with a little fresh lime water and hold this over the lighted
gas jet. In a few moments a change takes place in the water. The water
turns somewhat milky. This indicates the presence of carbonic acid gas,
and the formation of carbonic acid gas, when burning is going on, means
the presence of carbon.

From these two experiments we gather that the gas in the jet contains
hydrogen and carbon. All kinds of illuminating gas contain these two
substances. Sometimes there are small quantities of other substances
present, but the value of gas for lighting depends on hydrogen and
carbon.

We have already learned about hydrogen, but it would be well to
re-learn about carbon.

Carbon is an element, and an extremely important one, for a large part
of the composition of every living thing is carbon. It is found in
more compounds than any other element. Almost pure carbon can easily
be obtained by heating a piece of wood, in a covered utensil, until it
is turned into charcoal. Charcoal, which is black, is composed almost
entirely of carbon. It is a very interesting product in all ways; in
connection with gas we are particularly interested in the fact that
carbon will burn when heated in the air or in oxygen.

Charcoal is very much like hard coal, both being formed in practically
the same way. Ages of years ago many large forests of trees were buried
under a layer of soil and rocks, during changes that occurred in the
earth’s surface, and the hot inside earth slowly heated the wood, until
almost nothing was left but the carbon.

[Illustration: WHERE THE GAS IS TAKEN FROM THE COAL

GENERATOR HOUSE AND 175-FT. STACK.

In the process of gas making, coal is placed in the generator and
heated to an incandescent state, then from the top or bottom steam is
admitted and forced through the heated coal, producing a crude water
gas which is passed on to the carbureter. In this shell enriching oil
is produced, but as the oil and the water gas do not effectually unite,
they are passed on to the superheater, where, as its name implies, they
are subjected to a high temperature which thoroughly gasifies them into
a permanent gas.]

[Illustration: AN INTERIOR VIEW OF GENERATOR HOUSE.]

* Pictures on Gas Manufacture by courtesy of the Consolidated Gas,
Electric Light and Power Co. of Baltimore.

[Illustration: ILLUMINATING GAS MUST BE SCRUBBED

SHAVING SCRUBBERS.

After passing into the scrubbers the gas is cooled, passed into the
scrubbers, and by contact with wooden slat trays, made up like screens;
a large portion of the tar is removed from the gas, the tar passing off
to large receptacles.]

Soft coal was formed in much the same manner, but the process was not
so completely finished. Mixed with the carbon in soft coal we find
quite a good deal of other substances, of which hydrogen forms the
principal part. This is what makes soft coal valuable in the making of
illuminating gas.

When soft coal is heated in a closed receptacle a gas is formed which
will burn. To show this we have only to take an ordinary clay pipe,
put a little piece of coal in the bowl, close the top with wet clay,
and put the bowl part of the pipe in the fire. When it is quite hot, a
gas will be found coming out of the stem of the pipe, which will, when
lighted, burn.


The Story In a Gas Jet.

~HOW ILLUMINATING GAS IS MADE~

Soft coal is heated in large tubes of fire clay called retorts, and the
gas that is formed is then collected in a large tank and sent through
pipes to our homes after being purified. The part of the coal that is
left consists largely of carbon and is what we call coke.

While the gas that comes directly from coal will burn if lighted, it is
not a desirable gas to burn in our homes, because it contains a number
of substances that should be eliminated before it is used for lighting.


How the Gas Is Purified.

From the clay retorts the gas passes through horizontal pipes
containing water. This cools it and takes out of it most of the tar
and water vapor that are driven off with the gas when formed. These
substances settle in the water. The gas then goes through a series
of curved pipes, which are air cooled. These pipes constitute what
is known as an atmospheric condenser. From these the gas goes into
a series of receptacles containing wooden slat trays, made up like
screens. These receptacles are called the scrubbers, and they take out
of the gas the last traces of tar and some of the other compounds found
present. The removal of the sulphur is very important, for burning
sulphur gives off a gas which is not only extremely impure to breathe,
but also injurious to the health.

From the scrubbers the gas goes on through pipes to the purifiers--boxes
which contain wood shavings coated with iron rust upon which the sulphur
is deposited by chemical action. At the same time the lime absorbs a
small quantity of carbonic acid gas, which is formed with the other
gases. From the purifiers the gas passes into the great iron tanks, in
which it is stored until needed.

The gas in the tanks consists chiefly of hydrogen, a number of
compounds of hydrogen and carbon, and a small amount of a compound
of carbon and oxygen containing less oxygen than carbonic acid gas,
known as carbon monoxide. The hydrogen and carbon monoxide burn with
a very pale flame, which gives but little light and much heat. The
light-giving quality of the gas is found in the compounds of carbon and
hydrogen. When these burn, the particles of carbon are heated white hot
and glow very brightly, making a luminous flame.

There are, of course, some impurities in the purified gas. These are
compounds containing sulphur and ammonia. The quantities of these
substances, however, are so small that they are harmless; but the
compounds taken out in the process of purifying the gas are saved, as
considerable use is made of them. The water used for washing the gas is
heavily charged with ammonia and is, in fact, the chief source of the
ammonia sold by druggists.

[Illustration: HOW THE IMPURITIES ARE TAKEN FROM THE GAS

PURIFYING BOXES.

The principal impurity to be removed is sulphur, and this is
accomplished by passing the gas through large iron rectangular boxes
filled with wood shavings coated with iron rust upon which the sulphur
is deposited by chemical action.]

[Illustration: STATION METER HOUSE, SHOWING CONSTRUCTION OF TWO NEW
13-FT. METERS.]

[Illustration: HOW THE METER MEASURES THE GAS

Fig 1

Fig 3

Fig. 2.

Fig 4

Gas first enters inlet pipe _A_ (Fig. 3) passing along _A1_ into
covered valve chamber _B_ up through orifice _O_. It then passes down
through two of the valve ports at the same time, ports _C_ and _D1_
(Fig. 2). Before _C1_ (Fig. 3) has gotten to its extreme opening, the
valve on the opposite side has moved to allow gas to pass down port
_D_. On every quarter turn of tangent _P_, one port is opening to
receive gas which passes down through the valve ports into the chambers
below (see arrows on Fig. 2), which shows the gas passing into chamber
_F_. The pressure being greater on the outside of the diaphragm, forces
the diaphragm inward and expels the gas from the inside of _D2_ through
_D_ and passes over the cross-bar into the fork channel (see Fig.
1). On the other side gas is passing down through port _D1_ (Fig. 2)
entering diaphragm _D3_, the pressure being greater on the inside of
_D3_ therefore forces the diaphragm outward and expels the gas from
the outside of diaphragm _D3_; out through port _C1_ into fork channel
same as shown in (Fig. 1). All exhaust gas from the chambers below
is checked from entering the chamber _B_ by the slide valve _G_ and
_G1_ (Fig. 2). Instead of passing into chamber _B_ it passes over the
cross-bars between _D1E1_ and _C1E1_ into the fork channels, then to
outlet pipe _N_ (Fig. 3) to house pipe.

NOTE: All gas registered must pass through outlet _N_.]

In addition to coal gas made in the way just described, there is
another form of illuminating gas, in the manufacture of which coal is
indirectly employed. This gas, known as water gas, because it is formed
by the decomposition of water, is produced by passing steam over red
hot carbon, in the form of hard coal or coke. When this is done, the
hydrogen in the steam is set free and the oxygen combines chemically
with the carbon, to form the carbon monoxide, that was mentioned as
being present, in small proportions, in ordinary coal gas. This carbon
monoxide is poisonous, if much of it is breathed, and as it has no
odor it is difficult to detect when escaping. A number of deaths have
resulted from water gas for this reason, and in some states the laws
forbid its use for lighting purposes.

When water gas is used it must be enriched with some other substances
before it will yield much light. You have already learned that neither
hydrogen nor carbon monoxide burns with a bright flame, and you will
see that water gas must have something added to it to fit it for
lighting purposes. The substance usually added is the vapor of some
light, volatile oil, like gasoline. This vapor is composed of compounds
of carbon and hydrogen, and when it is mixed with the water gas it
forms a gas that yields a very satisfactory light; and that may be
produced more cheaply than common coal gas.

There remains one more form of illuminating gas which has been the
subject of much discussion in recent years, namely, acetylene. This is
a compound of carbon and hydrogen, in which there is twelve times as
much carbon as hydrogen. It has not been discovered recently, for it
was known early in the nineteenth century, but its possible use for
lighting purposes was not considered then.

Attention was directed to it a few years ago by the discovery of a
substance called calcium carbide. This is a compound of carbon and the
metal calcium, formed by heating to a very high temperature a mixture
of coal and lime. It has the peculiar property of decomposing, when
treated with water. The calcium present combines with the oxygen and
half the hydrogen of the water, to form common slacked lime or calcium
hydrate, while the carbon and the remainder of the hydrogen combine to
form acetylene gas.

The gas formed in this way needs no purifications before burning; it
can be produced in small generators, and the production can be checked
at any time. When burned in the proper form of burner it yields the
brightest of all gas flames. For these reasons it is adapted for use in
small villages and for lighting single houses. It is also frequently
used in magic lanterns, where a strong and steady light is necessary.
But the cost of producing acetylene in large quantities is greater than
that of coal gas, and it seems extremely unlikely that it will ever be
much used for lighting large cities and towns.




How the Light Gets Into the Electric Light Bulb.


The incandescent lamp was invented in 1879 and the patents were granted
to Thomas A. Edison. There were, however, a number of electrical men
who were working on the idea at this time who deserve a great deal of
credit for developing the lamp.

The incandescent lamp, which is used chiefly for house lighting,
consists of a glass bulb from which the air has been exhausted by
pumps and chemical processes--in which there is a thin filament of
tungsten metal wound on what is called an arbor (as shown in Fig. 4).
This filament opposes high resistance to the passage of the current
of electricity, and, consequently, is heated to incandescence when
a current passes through it. The removal of the air from the bulb
prevents the tungsten metal from burning up, as it would do if oxygen
were present.

The filaments of the first lamps were made of vegetable fibre. The next
development was the cellulose process, which is still used in carbon
and metallized lamps, although a number of processes are used now which
improve the filament considerably.

The discovery that tungsten metal could be used in incandescent lamps
was made in 1906. The first tungsten lamp manufactured in America was
made in 1907.

[Illustration: THE DEVELOPMENT OF INCANDESCENT LAMPS

Edison’s first lamp with a filament of bamboo fibre.]

[Illustration: The carbon lamp--the oldest form of incandescent lamp.]

[Illustration: Standard Mazda lamp--the highest development of the
incandescent lamp.]

[Illustration: The Tantalum lamp developed just before the Mazda lamp.]

[Illustration: Improved Mazda lamp for lighting large areas--the most
efficient lamp ever made.]

The filaments of the first tungsten lamps were composed of two or
three short pieces of wire. In 1910, however, a lamp with a continuous
tungsten filament was invented which increased the strength of the lamp
wonderfully.

Mazda is a trade name given to all metal filament lamps made by the
prominent American lamp manufacturers.

The reason that the Mazda lamp is so much more efficient than the
carbon filament lamp is because the tungsten filament can be burned at
a much higher temperature than the present carbon filament, without
seriously blackening the bulb.




How Does an Arc Light Burn?


In the arc light a current of electricity is made to leap across from
the tip of one rod of carbon to the tip of another that is held a short
distance from the first. In passing across the current does not follow
a straight path, but makes a curve, or arc, whence comes the name “arc
light.”

In this form of light the carbons are not enclosed in a space from
which air is excluded, consequently there is some destruction of the
carbon. The light is due to the fact that the air between the tips of
the carbon rods opposes a high degree of resistance to the current, so
that the rods become intensely hot at their tips. The high degree of
heat causes a slow burning of the carbon at the tips, and the small
particles that burn are heated white hot before they are consumed, thus
producing light.

In order to keep the light from an arc light uniform in strength, it is
necessary to keep the tips of the carbon rods always the same distance
apart. This is practically impossible, and, as a result, the arc light
does not produce light that is well adapted for reading or for other
purposes that require constant use of the eyes. The light produced by
the arc light is very powerful, however, and for that reason it is much
used for street lighting.




What Are X-Rays?


It was discovered by Professor Conrad Roentgen in 1895, that if a
current of electricity be passed through a certain form of glass
bulb, from which most of the air has been exhausted, a disturbance
is produced in the ether that bears some resemblance to light waves.
For want of a better name to give to a disturbance which was not well
understood, Roentgen called his discovery the X-Ray, but it is now
frequently called in his honor the Roentgen ray. The nature of this
disturbance is not yet known, but as it does not affect the eye it
is not light. These rays are produced with a glass vacuum tube and a
battery from which a current of electricity is sent through the tube.
The wires of the battery are connected with two electrodes, one of
which consists of a concave disk of aluminum, and the latter of a
flat disk of platinum. The X-rays are discharged in straight lines as
shown in the figure. The most striking properties of the X-ray is its
power to penetrate many substances that are impermeable to light. All
vegetable substances, and the flesh of animals, are penetrated by it
very readily. Glass, metals, bones, and mineral substances generally
are opaque to it. Consequently, when a limb, or even the body of an
animal, is exposed to X-rays they pass through the fleshy parts,
but are stopped by the bones. Certain substances have the property
of glowing, or becoming fluorescent, when exposed to the X-ray, and
when screens of paper are coated with these substances they form a
convenient means of detecting the presence of X-rays. By holding the
hand between a tube that is giving off X-rays and a screen of this
kind, the bones of the hand will be outlined in shadow on the screen,
and the rest of the surface will glow with a greenish light. If a
bullet or other piece of metal has become imbedded in the body, it may
easily be located, if it is not in a bone, and the extent of an injury
to a bone or a joint may be plainly shown. For this reason the X-ray is
now widely used by surgeons.




How Man Learned to Fight Fire.


When you see the modern fire engine racing through the streets, gongs
ringing, with the firemen hanging on and the police clearing the track,
you should remember that it has taken man a long time to learn as much
as he has about fighting fire.

No sooner did man learn to make fire than he found it necessary to
learn how to put it out.

The first fire apparatus of record is found in Rome. The Gauls burned
the city in 390 B. C., each citizen was ordered to keep in his house a
“machine for extinguishing fire.” This consisted of a syringe.

The first record of an actual machine for putting out fire is by Hero
of Alexandria. This contrivance, a “siphon used in conflagrations,” was
used in Egypt about a hundred and fifty years before Christ.

The first record of what we would call a fire department is also found
in Rome. A disastrous fire, occurring in the reign of Augustus called
his attention to the benefit of a regular fire brigade would bring. So
he organized a fire department. It consisted of seven companies of a
thousand men each.

The first real fire engines were used in 1633 at a big fire on London
Bridge. The first fire hose was invented by the two Van der Heydes in
1672. One of the earliest engines used consisted of a tank drawn by two
horses, which threw a stream an inch in diameter to a height of eighty
feet. An improved engine was invented in 1721 by Newsham, of London,
and the first engine used in the United States was made by Newsham. The
first steam fire engine was invented by John Braithwaite, of London, in
1829.

Fire alarms came into use in medieval times. It was the custom, in many
of the towns to have a watchman stationed on a high building whose duty
it was to look for fires. As soon as he saw one, he gave warning by
blowing a horn, firing a gun, or ringing a bell.

The first London fire department consisted of ten men of each ward.

The first municipal American fire department was created in Boston in
1678. The fire engine was a hand pump bought in England.

The first leather fire hose was made in America in 1808 in
Philadelphia. Rubber hose was first made in England at about 1820.




How Did Man Learn to Cook His Food?


The primitive man lived on raw food--raw flesh, roots, fruits and nuts.
There must have been a time when he lived thus because there was a time
when he had no fires and no knowledge of how to make a fire. There are
no records, however, to show when man learned that cooked food was best.

It must have come about almost simultaneously with his knowledge of
fire, for the art of cooking goes back to the first knowledge of fire.
We do not know either how man learned to make a fire. The earliest
nations of which we have any record seem to have been acquainted with
fire and certain methods for producing it. Not only one but all early
nations seem to have been possessed of this knowledge. Occasionally
travellers have reported that people have been found who were
unacquainted with either fire or cooking, but investigation has always
proven these reports unauthentic. Cookery has always been found in
practice where people knew about fire.

It is strange how man has lost track of the beginning of his knowledge
of fire and cookery, because fire represents the beginning of man’s
culture and cookery goes hand in hand with it.

There are many legendary accounts of how man learned the value of
cooked food, all of which are based upon the accidental burning or
roasting of animals or birds. Perhaps, therefore, Charles Lamb’s “Roast
Pig” story, which we read with much laughter in our school readers, was
quite accurate from a historical standpoint. According to the story
a man’s house burned and he cried more over the fate of his pet pig
than about the loss of his house. He kept his pig in the house you will
remember and as soon as the fire died away he rushed into the debris
to look for his pet pig, hoping still to rescue him. He found him in a
corner and made haste to pick him up and carry him into the open air.
But the poor pig had been roasted to a turn and was still hot. The
man’s fingers went right into the well done roast pig and were burned.
With a cry he withdrew his fingers and put them into his mouth to blow
on them and thus he secured his first taste of roast pig, which he
found so much to his taste that he repeated the operation of licking
his fingers.

While this is but a story, it is quite likely historically correct as
to this discovery of the value of cooked food to some of the early
nations. No doubt Fire and Cookery were developed together.

When man had learned to make fire, he found that it often got beyond
his control. Here and there he would set the woods on fire quite
without intention perhaps, but with damaging results. He would watch
the conflagration and, when it was passed, he would find the baked
bodies of deer or other animals which had been overcome by the fire
and learned that baked meats were good to the taste and more easily
digestible than raw meats.




Why Does a Sponge Hold Water?


A sponge will hold water because it has, on account of the plan on
which it is grown the power of capillary attraction. The sponge is made
up of little hair like tubes. If you take a glass tube, open at both
ends and immerse one end in a vessel of water, you will find that the
water will rise in the tube to a level higher than the surface of the
water in the vessel. The smaller the hole through the glass tube, the
higher the water will rise. This is caused by the cohesion of the water
against the inside surface of the hole in the tube and causes a pull
upward. The water is pulled up into the tube because the surface of the
tube has a greater cohesive attraction for the water than for the air
which was in it and the air is forced out partly. Some liquids, such
as mercury will not rise in the same way, but is depressed in a glass
tube, since it cannot adhere to glass. Mercury however will run or rise
in a tin tube, just as water in a glass tube, because it adheres to the
tin.

Now a sponge is merely a lot of capillary tubes which have the same
power of pulling up the water as the glass tube. The tubes in a sponge
are so fine that the water will rise to the entire length of the tubes.
In addition, this adhesive quality of water to the inside of the tubes
in the sponge is so strong, that the sponge can be taken entirely out
of the water and the water will remain in it.




Why Is the Right Hand Stronger Than the Left?


The right hand is stronger than the left only in case you are
right-handed. If you have the habit of being left-handed, your left
hand becomes stronger. If you are truly ambidextrous, your strength
will be the same in both hands.

We get our strength by moving the various parts of the body, i. e., by
using them. When a little baby stretches his arms and legs and kicks,
he is only exercising naturally, making the blood circulate.

You can prove that the fact that your right hand is stronger than your
left because of the greater use or exercise you give it, by tying your
right arm close to your side and keeping it in that condition without
using it for several weeks. When you remove the bands which held it
tight, you will find your arm has lost its strength and that now your
left hand is stronger. If, however, you are left-handed and tie that
hand down for the same length of time, your right hand would be the
stronger. This shows that the strength we have in our arms and legs,
and other parts of the body, is developed by using them and giving them
rational exercise. Of course, it is possible to over-use a part of
the body, but you will notice that nature always gives us a warning by
making us tired before we come to the point where further use of that
particular part of the body would cause injury.




Why Do My Muscles Get Sore When I Play Ball In the Spring?


They do this because you have probably not been exercising the
particular muscles which you employ in throwing a ball enough in the
winter to keep you in good condition. Muscles which have been developed
through use or work need more work to keep them in condition. In a
sense certain of the muscles which you employ in playing ball have
been treated during the winter very much as if you had tied them down,
as we suggested you might do with your arm. You have not been using
them--they have not been doing enough work, and they begin to lose
their strength when for any period they have not been used enough. The
soreness that you feel is the natural condition that arises when you
begin to use a muscle that has been idle for some time.




Why Does a Barber’s Pole Have Stripes?


In early years the barber not only cut hair and shaved people, but he
was also a surgeon. He was a surgeon to the extent that he bled people.
In early times our knowledge of surgery was practically limited to
blood letting. A great many of the ailments were attributed to too much
blood in the body, and when anything got wrong with a man or woman, the
first thing they thought of was to reduce the amount of blood in the
body by taking some of it out.

The town barber was the man who did this for people and his pole
represented the sign of his business.

The round ball at the top which was generally gilded represents the
barbering end of the business. It stood for the brass basin which the
barber used to prepare lather for shaving customers.

The pole itself represents the staff which people who were having blood
taken out of their bodies held during the operation. The two spiral
ribbons, one red and one white, which are painted spirally on the pole,
represented the bandages. The white one stood for the bandage which was
put on before the blood was taken out and the red one the bandage which
was used for binding up the wound when the operation was completed.




How Was the Flag Made?


The design of our flag was outlined in a congressional resolution
passed on June 14, 1777, which stated “that the flag of the thirteen
United States be thirteen alternate stripes red and white; that the
union be thirteen stars, white in a blue field, representing the new
constellation.” After Vermont and Kentucky had been admitted to the
Union, Congress made a decree in 1794 that after May 1, 1795, “the flag
of the United States be fifteen stripes alternate red and white and
that the Union be fifteen stars white on a blue field.” This made the
stars and stripes again equal and it was the plan to add a new stripe
and a new star for each new state admitted to the Union. Very soon,
however, it was realized that the flag would be too large if we kept on
adding one stripe for each new state admitted to the Union, so on April
4, 1818, Congress passed a resolution reducing the number of stripes to
thirteen once more to represent the original colonies, and to add only
a new star to the field when a new state was admitted to the Union. At
this time there were twenty states in the Union. Since that time none
of the flags of the United States have more than thirteen stripes while
a new star has been added for each state until now we have forty-eight
stars, representing the forty-eight states.




Why Are Some Guns Called Gatling Guns?


A gatling gun is a kind of gun invented by Richard Jordan Gatling
in 1861 and 1862 and so it receives its name from its inventor. The
original gatling gun had ten parallel barrels and was capable of firing
1,000 shots per minute when operated by hand power. It was discharged
by turning a crank and would shoot in proportion to the rapidity with
which the crank was turned. It was at first not a huge success but has
from time to time been improved so that the crank is now turned by
electric power and about fifteen hundred shots per minute can be fired
with it.




How Did Hobson’s Choice Originate?


As used today, this expression means a choice with only one thing to
choose. Tobias Hobson was a livery stable keeper at Cambridge, England,
during the reign of King Charles I. He kept a stable of forty horses
which he hired out by the hour or day, and was famous in his day so far
as a livery stable keeper could be.

When you went to Hobson to hire a horse, you had the privilege of
looking over all the horses in the stable to decide which one you would
like to drive, but he always made you take the one in the stall nearest
the door. In this way all the horses in the stable were worked in turn
and while you might pretend to choose your own horse, you really had no
choice--you had to take the one nearest the door or none. As soon as a
horse was hired, the other horses in the stable were moved up, each one
to the stall next towards the door so there was always a horse in the
stall nearest the door.




Why Do They Call It a Honeymoon?


The word Honeymoon which is commonly used to describe the first
few weeks after marriage, has always meant the first month or moon
after marriage, but does not have any reference to the month or moon
excepting as that describes a certain period of time.

The word originated in an old custom quite common among newly married
couples among the ancient Teutons of drinking a kind of wine made from
honey during the first thirty days after being married.

In these days newly married couples generally take a trip away from
home for a short or longer period after their wedding day and this is
called the honeymoon whether it is but a few days or three months or
more. The custom of drinking wine made from honey has been abandoned so
that the word is now used in an entirely different sense than formerly.




Why Is a Horseshoe Said to Bring Good Luck?


The luck of the horseshoe comes from three lucky things always
connected with horseshoes. These consist of the following facts: It is
the shape of a crescent; it is a portion of a horse; it is made of iron.

Each of these has from time immemorial been considered lucky. Anything
in the shape of a crescent was always considered a thing to bring luck.
From the earliest times, too, at least since the world knew something
of the qualities of iron, iron has been regarded as a thing to give
protection and incidentally that would involve good luck. And lastly
the horse, since the days of English mythology, has been regarded as
a luck animal. When, then, we had a combination of the three--the
crescent, the iron and the horse in one object, it became a true lucky
sign in the eyes of the people.




Some Wonders of the Human Body.


There are said to be more than two million little openings in the skins
of our bodies to serve as outlets for an equal number of sweat glands.
The body contains more than two hundred bones. It is said that as much
blood as is in the entire body passes through the heart every minute,
i.e., all the blood in the body goes in and out of the heart once every
minute. The lung capacity of the average person is about 325 cubic
inches.

With every breath you inhale about two-thirds of a pint of fresh air
and exhale an equal amount if you breathe normally.

The stomach of the average adult person has a capacity of about five
pints and manufactures about nine pounds of gastric juice daily.

There are over five hundred muscles in the body all of which should be
exercised daily to keep you in the best condition. The average adult
human heart weighs from eight to twelve ounces and it beats about
100,000 times every twenty-four hours. The perspiration system in the
body has only very small ducts or pipes, but there are about nine miles
of them. The average person takes about one ton of food and drink each
year. We breathe about eighteen times a minute, which amounts to about
3,000 cubic feet an hour.




Where Did the Expression “Kick the Bucket” Originate?


The expression originally came from the method used in stringing a
hog after killing it. The pig after being slaughtered was hung by the
hind legs. A piece of bent wood was passed in behind the tendons of
each of the hind legs and the pig hung up by this stick of wood much
like we hang up clothes with a clothes hanger today. The piece of wood
was called a bucket. The “bucket” part of the expression does not,
therefore, refer to a bucket at all but to this bent piece of wood. All
are not agreed on this explanation, however, as it does not explain
where the “kick” comes in. Many investigators hold to the belief that
a man named Bolsover was the first to “kick the bucket” literally and
that the expression came from the manner of his death. He stood on a
pail or bucket while arranging to hang himself by tying a rope around
his neck and to a beam which he could not reach without standing on the
bucket. When ready he kicked the bucket out from under his feet and
so succeeded in carrying out his own wishes and in so doing coined a
famous expression which still means “to die.”




How Did the Word “News” Originate?


The word “News” which was created to describe what newspapers are
supposed to print, came from the four letters which have for ages
been used as abbreviations of the directions of the compass. In this
N stands for North, E for East, S for South and W for West, and in
illustrating the points of the compass the following diagram has long
been used:

     N
     |
  W--+--E
     |
     S

The earliest newspapers always printed this sign on the front pages of
their papers in every issue. This was done to indicate that the paper
printed all the happenings from four quarters of the globe.

Later on some enterprising newspaper man who may have forgotten the
original significance of the letter in the diagram, arranged the
letters N. E. W. S. in a straight line at the head of the paper and
that is how what we read in the papers came to be known as news.

Almost one-half the whole number of newspapers published in the world
are published in the United States and Canada.




Who Made the First Umbrella?


No one knows who made the first umbrella but we know that Jonas Hanway
of London was the first man to carry one over his head to keep off the
rain.

Umbrellas seem to have been known as far back as the days of Ninevah
and Persepolis, for representations of them appear frequently in the
sculptures of those early days. The women of ancient Rome and Greece
carried them but the men never did.

Mr. Hanway is said to be the first man who walked in the streets of
London with an open umbrella over his head to keep off the rain. He is
said to have used it for thirty years before they came into general use
for this purpose.

[Illustration: HOW MAN LEARNED TO TELL TIME

The first picture shows what was probably man’s first method of telling
time. The principle was the same as that of the sun-dial. It provides
to-day an accurate method of telling time.

Of course, man in the early days needed to find some other means of
noting the passing of time at night, for then the sun cast no shadow
for him. His ingenuity taught him to make a candle which was light and
dark in alternate rings, and as each section burned he made a mark to
record the passing of a certain length of time. Before candles were
invented he used a rope in which he tied knots at equal spaces apart
and which he burned as shown in the third picture.]




The Story in a Time Piece


What Is Time?

Time, as a separate entity, has not yet been defined in language.
Definitions will be found to be merely explanations of the sense in
which we use the word in matters of practical life. No human being can
tell how long a minute is; only that it is longer than a second and
shorter than an hour. In some sense we can think of a longer or shorter
period of time, but this is merely comparative. The difference between
50 and 75 steps a minute in marching is clear to us, but note that we
introduce motion and space before we can get a conception of time as a
succession of events, but time, in itself, remains elusive.

In time measures we strive for a uniform motion of something and this
implies equal spaces in equal times; so we here assume just what we
cannot explain, for space is as difficult to define as time. Time
cannot be “squared” or used as a multiplier or divisor. Only numbers
can be so used; so when we speak of “the square of the time” we mean
some number which we have arbitrarily assumed to represent it. This
becomes plain when we state that in calculations relating to pendulums,
for example, we may use seconds and inches--minutes and feet--or
seconds and meters--and the answer will come out right in the units
which we have assumed. Still more, numbers themselves have no meaning
till they are applied to something, and here we are applying them to
time, space and motion; so we are trying to explain three abstractions
by a fourth! But, happily, the results of these assumptions and
calculations are borne out in practical human life, and we are not
compelled to settle the deep question as to whether fundamental
knowledge is possible to the human mind.


What Was Man’s First Division of Time?

Evidently, man began by considering the day as a unit and did not
include the night in his time-keeping for a long period. “And the
evening and the morning were the first day,” Gen. i, 5; “Evening and
morning and at noonday,” Ps. lv, 17, divides the day (“sun up”) in two
parts. “Fourth part of a day,” Neh. ix, 3, shows another advance. Then
comes, “are there not twelve hours in a day,” John xi, 9. The “eleventh
hour,” Matt. xx, 1 to 12, shows clearly that sunset was 12 o’clock. A
most remarkable feature of this 12-hour day, in the New Testament, is
that the writers generally speak of the third, sixth and ninth hours,
Acts ii, 15; iii, 1; x, 9. This is extremely interesting, as it shows
that the writers still thought in quarter days (Neh. ix, 3) and had
not yet acquired the 12-hour conception given to them by the Romans.
They thought in quarter days even when using the 12-hour numerals!
Note, further, that references are to “hours”; so it is evident that
in New Testament times they did not need smaller subdivisions. “About
the third hour” shows the mental attitude. That they had no conception
of our minutes, seconds and fifth-seconds becomes quite plain when
we notice that they jumped down from the hour to nowhere, in such
expressions as “in an instant--in the twinkling of an eye.”

Before this the night had been divided into three watches (Judges vii,
19). Poetry to this day uses the “hours” and the “watches” as symbols.

This twelve hours of daylight gave very variable hours in latitudes
some distance from the equator, being long in summer and short in
winter. The amount of human ingenuity expended on time measures so as
to divide the time from sunrise to sunset into twelve equal parts is
almost beyond belief. In Constantinople, to-day, this is used, but in a
rather imperfect manner, for the clocks are modern and run twenty-four
hours uniformly; so the best they can do is to set them to mark twelve
at sunset. This necessitates setting to the varying length of the days,
so that the clocks appear to be sometimes more and sometimes less
than six hours ahead of ours. A clock on the tower at the Sultan’s
private mosque gives the impression of being out of order and about six
hours ahead, but it is running correctly to their system. Hotels in
Constantinople often show two clocks, one of them to our twelve o’clock
noon system. Evidently the Jewish method of ending a day at sunset is
the same and explains the command, “let not the sun go down upon thy
wrath,” which we might read, “do not carry your anger over to another
day.”

This simple line of steps in dividing the day and night is taken
principally from the Bible because every one can easily look up the
passages quoted and many more, while quotations from books not in
general use would not be so clear.


How Did Man Begin to Measure Time?

Now, as to the methods of measuring time, we must use circumstantial
evidence for the prehistoric period. The rising and the going down of
the sun--the lengthening shadows, etc., must come first, and we are on
safe ground here, for savages still use primitive methods like setting
up a stick and marking its shadow so that a party trailing behind can
estimate the distance the leaders are ahead by the changed position of
the shadow. Men notice their shortening and lengthening shadows to this
day. When the shadow of a man shortens more and more slowly till it
appears to be fixed, the observer knows it is noon, and when it shows
the least observable lengthening then it is just past noon. Now, it is
a remarkable fact that this crude method of determining noon is just
the same as “taking the sun” to determine noon at sea. Noon is the time
at which the sun reaches his highest point on any given day.

[Illustration: The Sun-dial is only an improvement on the stick which
cast a shadow which enabled man to tell the time of day at any hour.
The shadow moves around the dial, falling on the numbers on the circle.]


How Is the Time Calculated at Sea?

At sea this is determined generally by a sextant, which simply measures
the angle between the horizon and the sun. The instrument is applied a
little before noon and the observer sees the sun creeping upward slower
and slower till a little tremor or hesitation appears, indicating that
the sun has reached his height--noon. Oh! you wish to know if the
observer is likely to make a mistake? Yes, and when accurate local time
is important, several officers on a large ship will take the meridian
passage at the same time and average their readings, so as to reduce
the “personal error.” All of which is merely a greater degree of
accuracy than that of the man who observes his shadow.

The gradual development of the primitive shadow methods culminated in
the modern sun-dial. The “dial of Ahas” (Isa. xxxviii, 8), on which
the sun went back ten “degrees,” is often referred to, but in one of
the revised editions of the Bible the sun went back ten “steps.” This
becomes extremely interesting when we find that in India there still
remains an immense dial built with steps instead of hour lines.

In a restored flower garden, within one of the large houses in the
ruins of Pompeii, may be seen a sun-dial of the Armillary type,
presumably in its original position. It looks as if the plane of the
equator and the position of the earth’s axis must have been known to
the maker.

Both these dials were in use before the beginning of our era and were
covered by the great eruption of Vesuvius in 79 A.D., which destroyed
Pompeii and Herculaneum.

~THREE GREAT STEPS IN MEASURING TIME~

Modern sun-dials differ only in being more accurately made and a few
“curiosity” dials added. The necessity for time during the night, as
man’s life became a little more complicated, necessitated the invention
of time machines. The “clepsydra,” or water-clock, was probably the
first. A French writer has dug up some old records putting it back
to Hoang-ti 2679 B.C., but it appears to have been certainly in use
in China in 1100 B.C., so we will be satisfied with that date. In
presenting a subject to the young student it is sometimes advisable to
use round numbers to give a simple comprehension and then leave him to
find the overlapping of dates and methods as he advances. Keeping this
in mind, the following table may be used to give an elementary hint of
the three great steps in time measuring.

Shadow time, 2000 to 1000 B.C.

Dials and water-clocks, 1000 B.C. to 1000 A.D.

Clocks and watches, 1000 to 2000 A.D.

Gear-wheel clocks and watches have here been pushed forward to 2000
A.D., as they may last to that time, but no doubt we will supersede
them. At the present time science is just about ready to say that a
time measurer consisting of wheels and pinions--a driving power and a
regulator in the form of a pendulum or balance, is a clumsy contrivance
and that we ought to do better very soon.

It is remarkable how few are aware that the simplest form of sun-dial
is the best, and that, as a regulator of our present clocks, it is
good within one or two minutes. No one need be without a “noon-mark”
sun-dial; that is, every one may have the best of all dials. Take a
post or any straight object standing “plumb,” or best of all the corner
of a building. In the case of the post, or tree trunk, a stone (shown
in solid black) may be set in the ground; but for the building a line
may often be cut across a flagstone of the footpath. Many methods may
be employed to get this noon mark, which is simply a north and south
line: Viewing the pole star, using a compass (if the local variation
is known) or the old method of finding the time at which the shadow of
a pole is shortest. But the best practical way in this day is to use a
watch set to local time and make the mark at 12 o’clock.

[Illustration:

  Drawing by James Arthur.

A form of Sun-dial that is as good to-day as any dial for determining
noon.]

On four days of the year the sun is right and your mark may be set at
12 on these days, but you may use an almanac and look in the column
marked “mean time at noon” or “sun on meridian.” For example, suppose
on the bright day when you are ready to place your noon mark you read
in this column 11.50, then when your watch shows 11.50 make your noon
mark to the shadow and it will be right for all time to come. Owing
to the fact that there are not an even number of days in a year, it
follows that on any given yearly date at noon the earth is not at the
same place in its elliptical orbit, and the correction of this by the
leap years causes the equation table to vary in periods of four years.
The centennial leap years cause another variation of 400 years, etc.,
but these variations are less than the error in reading a dial.


How Did Men Tell Time When the Sun Cast No Shadows?

[Illustration:

  Photo by James Arthur.

WATER CLOCKS FOR TELLING TIME

This picture shows the hour-glass or sand-glass. It is really a type of
water-clock, being based on the same principle. The upper glass bulb
was filled with sand and this sand fell through a little hole between
the two bulbs. When the sand had all gone through, the glass was turned
upside down and the operation repeated.

TIME-BOY OF INDIA.--WATER-CLOCK.

The Water-clock consisted of a large vessel filled with water, on the
surface of which was placed a smaller vessel, really a gong, with a
hole in the bottom. The water gradually filled the smaller vessel, and
it sank. The Time-boy sat beside the Water-clock and as soon as the
vessel sank he fished it out, emptied it, struck the gong one or more
times and set it on the water again.]

During the night and also in cloudy weather the sun-dial was useless,
and we read that the priests of the temples and monks of more modern
times “went out to observe the stars” to make a guess at the time
of night. The most prominent type after the shadow devices was the
“water-clock” or “clepsydra,” but many other methods were used, such as
candles, oil lamps, and in comparatively late times, the sand-glass.
The fundamental principle of all water-clocks is the escape of water
from a vessel through a small hole. It is evident that such a vessel
would empty itself each time it is filled in very nearly the same
time. The reverse of this has been used, as shown in the picture of
the Time-boy of India. He sat in front of a large vessel of water and
floated a bronze cup having a small hole in its bottom in this large
vessel, and as the water ran in through the hole the cup sank. The boy
then fished it up and struck one or more blows on it as a gong. This he
continued and a rude division of time was obtained--while the boy kept
awake!

[Illustration: Drawing from description by James Arthur.

The “Hon-woo-et-low,” Canton, China. Copper jars dropping water.]

The most interesting of all water-clocks was undoubtedly the “copper
jars dropping water,” in Canton, China, where it can still be seen.
Referring to the picture herewith and reading the four Chinese
characters downwards the translation is “Canton City.” To the left and
still downwards, “Hon-woo-et-low,” which is, “Copper jars dropping
water.” Educated Chinamen inform me that it is over 3000 years old.
The little open building or tower in which it stands is higher than
surrounding buildings. It is, therefore, reasonably safe to state that
the Chinese had a weather and time station over 1000 years before our
era.

[Illustration:

  Photo by James Arthur.

TOWER OF THE WINDS.

This tower is located at Athens, Greece. It was built about 50 B.C.
It is octagonal in shape and had at one time sun-dials on each of its
eight sides. On top was a bronze weather vane from which it derived its
name.]

~A PRIMITIVE TWELVE-HOUR CLOCK~

It is a 12-hour clock, consisting of four copper jars partially built
in masonry forming a stair-like structure. Commencing at the top jar
each one drops into the next downward until the water reaches the solid
bottom jar. In this lowest one a float, “the bamboo stick,” is placed
and indicates the height of the water, and thus in a rude way gives the
time. It is said to be set morning and evening by dipping the water
from jar 4 to jar 1, so it runs 12 hours of our time. What are the
uses of jars 2 and 3, since the water simply enters them and drips out
again? No information could be obtained, but I venture an explanation
and hope the reader can do better, as we are all of a family and
there is no jealousy. When the top jar is filled for a 12-hour run
it would drip out too fast during the first six hours and too slow
during the second six hours, on account of the varying “head” of water.
Now, the spigot of jar 2 could be set so that it would gain water
during the first six hours, and lose during the second six hours, and
thus equalize a little by splitting the error of jar 1 in two parts.
Similarly, these two errors of jar 2 could be again split by jar 3
making four small variations in lowest jar, instead of one large error
in the flow of jar 1. This could be extended to a greater number of
jars, another jar making eight smaller errors.

The best thing the young student could do at this point would be to
grasp the remarkable fact that the clock is not an old machine, since
is covers only the comparatively short period from 1364 to the present
day. Compared with the period of man’s history and inventions it is
of yesterday. Strictly speaking, as we use the word clock, its age
from De Vick to the modern astronomical is only about 540 years. If we
take the year 1660, we find that it represents the center of modern
improvements in clocks, a few years before and after that date includes
the pendulum, the anchor and dead beat escapements, the minute and
second hands, the circular balance and the hair spring, along with
minor improvements. Since the end of that period, which we may make
1700, no fundamental invention has been added to clocks and watches.
This becomes impressive when we remember that the last 200 years have
produced more inventions than all previous known history--but only
minor improvements in clocks! The application of electricity for
winding, driving, or regulating clocks is not fundamental, for the
time-keeping is done by the master clock with its pendulum and wheels,
just as by any grandfather’s clock 200 years old. This broad survey of
time measuring does not permit us to go into minute mechanical details.

[Illustration: THE FIRST MODERN CLOCK

  Drawing by James Arthur.

Modern clocks commence with De Vick’s of 1364, which is the first
unquestioned clock consisting of toothed wheels and containing the
fundamental features of our present clocks. References are often quoted
back to about 1000 A.D., but the words translated “clocks” were used
for bells and dials at that date; so we are forced to consider the De
Vick clock as the first till more evidence is obtained. It has been
pointed out, however, that this clock could hardly have been invented
all at once; and therefore it is probable that many inventions leading
up to it have been lost to history. That part of a clock which does the
ticking is called the “escapement,” and the oldest form known is the
“Verge.”]

~EARLIEST CLOCKS HAD NO DIALS OR HANDS~

Scattered references in old writings make it reasonably certain that
from about 1000 A.D. to 1300 A.D. bells were struck by machines
regulated with this verge escapement, thus showing that the striking
part of a clock is older than the clock itself. It seems strange to us
to say that many of the earlier clocks were strikers only, and had no
dials or hands, just as if you turned the face of your clock to the
wall and depended on the striking for the time.

[Illustration:

  Photo by James Arthur.

ENGLISH BLACKSMITH’S CLOCK.]

A good idea of the old church clocks may be obtained from the picture
herewith. Tradition has followed it down as the “English Blacksmith’s
Clock.” It has the very earliest application of the pendulum. The
pendulum is less than 3 inches long and is hung on the verge, or pallet
axle, and beats 222 per minute. This clock may be safely put at 250
years old, and contains nothing invented since that date. Wheels are
cast brass and all teeth laboriously filed out by hand. Pinions are
solid with the axles, or “staffs,” and also filed out by hand. It is
put together, generally by mortise, tenon and cotter, but it has four
original screws all made by hand with the file. How did he thread the
holes for these screws? Probably made a tap by hand as he made the
screws. But the most remarkable feature is the fact that no lathe was
used in forming any part--all staffs, pinions and pivots being filed by
hand. This is simply extraordinary when it is pointed out that a little
dead center lathe is the simplest machine in the world, and he could
have made one in less than a day and saved himself weeks of hard labor.
It is probable that he had great skill in hand work and that learning
to use a lathe would have been a great and tedious effort for him. So
we have a complete striking clock made by a man so poor that he had
only his anvil, hammer and file. The weights are hung on cords as thick
as an ordinary lead-pencil and pass over pulleys having spikes set
around them to prevent the cords from slipping. The weights descend 7
feet in 12 hours, so they must be pulled up--not wound up--twice a day.
The single hour hand is a work of art and is cut through like lace.
Public clocks may still be seen in Europe with only one hand. Many have
been puzzled by finding that old, rudely made clocks often have fine
dials, but this is not remarkable when we state that art and engraving
had reached a high level before the days of clocks.

[Illustration: THE LARGEST CLOCK IN THE WORLD

  Courtesy of Colgate and Company.

THE HANDS OF THE LARGEST CLOCK IN THE WORLD--ON THE ROOF OF THE COLGATE
FACTORY.

This big clock faces the giant office buildings of down-town New York.
Its dial is 38 feet in diameter and can be read easily at a distance
of three miles, so that passengers on the incoming liners pick out the
clock as one of their first sights of New York.

The next largest clock (on the Metropolitan Tower) is 26¹⁄₂ feet in
diameter; the Westminster clock of London, 22¹⁄₂ feet.

The great clock weighs approximately 6 tons. The minute hand, 20 feet
long, travels at its point 23 inches every minute; more than one-half
mile each day.

The bed of this clock is 4 feet in length, the wheels and gears being
made of bronze and pinions of hardened steel. The time train occupies
about one-third of the bedplate, and has a main time wheel measuring
18¹⁄₃ inches in diameter. This train is equipped with Dennison’s double
three-legged gravity escapement, which was invented by Sir Edmund
Becket, chiefly for use on the famous Westminster clock, installed
in the Parliament Buildings, in London, England. The use of this
escapement is most advantageous for a gigantic clock of this kind as it
allows the impulse given the pendulum rod to be always constant, and
therefore does not permit any change of power or driving force of the
clock to affect its time-keeping qualities.

It requires about 600 pounds of cast-iron to propel this time train,
and the clock is arranged to run eight days without winding. The
gravity arms of the escapement are fastened at a point very near the
suspension spring, and the arms are fitted with bronze roller beat pins.

The dial contains 1134 square feet, or about one thirty-fifth of an
acre. The numerals consist of heavy black strokes, 5 feet 6 inches
long and 30 inches wide at the outer end, tapering to a point at the
inner end. The circumference of the dial is approximately 120 feet. The
distance from center to center of numerals is 10 feet, and the minute
spaces are 2 feet.

The background on dial is painted white, and in the daytime the black
numerals show up distinctly. At night the numerals, or hour marks,
are designated by a row of incandescent bulbs placed in a trough 5
inches wide and 5 inches deep. The hands at night are outlined with
incandescent electric lights, there being 27 lamps on the hour hand and
42 lamps on the minute hand.]

[Illustration: THE MACHINERY WHICH RUNS A BIG CLOCK]

This picture shows the machinery necessary to operate a large modern
tower clock.

The mechanism is held in place and confined entirely within a cast-iron
structure which is firmly bolted to the floor. The wheels are composed
of bronze, the pinions of steel (hardened) and the gears are machine
cut. At the front of the clock is a small dial which enables one to
tell exactly the position of the hands on the outside dials, and there
is also a second hand to permit of very close regulation and adjustment.

Three ways are provided for the regulation. First by a knurled screw
at the top of bed frame. Second by a revolving disc at the bottom of
the pendulum ball. Very often by either of these two methods it is
impossible to bring the clock to fractional seconds, and in order to
permit of a nicety of adjustment there is a cup fitted at the top of
the ball so that by inserting or taking out lead pellets, the rating
can be brought to absolute time.

[Illustration: THE CLOCK IN INDEPENDENCE HALL

INDEPENDENCE HALL, PHILADELPHIA]

[Illustration: NEW YORK CITY HALL]




Where Does the Day Begin?


To understand this subject we must first appreciate that a day as we
think of it is a division of time made by man for the purpose of his
own reckoning. So far as the beginning of day is concerned, it begins
at a different place in the world every hour; yes, every minute and
every second in the day. As, however, the distance in feet where the
day begins from one minute to another is so short that we can hardly
notice it in such short measurements of time, we will look at the
answer to the question from hour to hour. When you understand the
subject from that point you can yourself see that the day actually
begins at a different point of the earth every minute and every second
of time.




How Much of the Earth Does the Sun Shine on at One Time?


The sun is shining on some part of the earth all the time and the
shining of the sun makes the difference between day and night. Wherever
the sun is shining it is day-time, and where the sun is not shining it
is night-time.

To illustrate we will make use of an ordinary orange and a lighted gas
jet. Let us take a long hat-pin and stick it through the orange from
stem to stem. Now hold the orange by the ends of the hat-pin up before
the lighted gas jet. You will notice that one-half of the orange is
lighted, while the other half is dark. Of course, it is the half of the
orange away from the light that is dark. Now, revolve the orange slowly
on the hat-pin axis toward the light. When you have turned the orange
half way round the part that was formerly dark is now lighted up and
the other part is now dark.

Now examine closely and you will see that just one-half of the orange
is lighted at one time and the other half is dark. You revolve the
orange in front of the light slowly and a portion of the surface of the
orange is always coming into the light, while a corresponding portion
of it on the opposite side is constantly going into the dark. In other
words, whatever the speed at which you revolve the orange toward the
light, one-half of it is always light and the other half is always dark.

This is exactly what happens in the relation of the earth to the sun
every day. One-half of the earth, which is continually revolving on
its axis, is facing the sun, and is, therefore, in the daylight, while
the other half of the earth’s surface is in darkness, because the
light from the sun does not strike any portion of it. If the earth
did not revolve one-half of it would always be in day-time, while the
other half would be continually having night-time. As the earth is
always moving or revolving the half where it is day-time is constantly
changing, so that the day is beginning on one-half of the earth’s
surface every second of the day. Actually, of course, then, if you live
on the east side of town day begins with you a little sooner than with
your chum who lives on the west side of town. We have come to measure
the beginning of day as sunrise and the beginning of night as sunset,
wherever we happen to be.

For convenience in setting clocks and in measuring time we do not take
into consideration these very slight differences in the rising and
setting of the sun, but set our clocks all alike in different parts
of the same town or city to avoid confusion. In fact, in order to
overcome the difficulties and confusions arising in reckoning the time
of the clock in different localities, and still keep the beginning of
what we call day-time constant with the hands of the clock, we have
agreed upon what we call standard time. We agreed upon this system
of fixing standard time because the actual sun time by which people
set their clocks up to a few years ago led to so many mistakes in
catching trains, keeping engagements and other misunderstandings where
the question of time was involved. Then when this system of standard
time was adopted the confusion became even worse, and the mistakes and
misses more numerous, because some people insisted on setting their
clocks to standard time and others insisted on sticking to the old sun
time schedule. So you could never tell by looking at the clock what
time it really was unless they put a sign on the clock saying what kind
of time they were going by. Finally, however, most of the people came
to appreciate that it would be a good idea to use one uniform system of
setting the clocks and of having them in harmony in a sense with the
other clocks in the world, and the adoption of the standard time plan
became universal. To make this system practical and effective, certain
points about equally distant from each other were selected, at which
point




Where Is the Hour Changed?


the hour would change for all points within that zone. Under this
system all timepieces in any one zone point to the same hour. So the
clock time changes only as you go east or west. All points on a north
and south line have the same time as the zone in which it is located.

For convenience in adjusting the time in America the country was
divided into four east and west zones. The first zone takes in
everything on a straight north and south line east of Pittsburg, and is
called Eastern time. The second zone extends from Pittsburg to Chicago,
and is called Central time; the third zone extends from Chicago to
Denver, and is called Mountain time; while the fourth zone extends
from Denver to the Pacific Ocean. These selections were made because
the sun actually rises about one hour later in Pittsburg than in New
York; one hour later in Chicago than in Pittsburg; one hour later in
Denver than in Chicago, and one hour later on the Pacific Coast than in
Denver. Under this plan when it is nine o’clock in New York it is only
eight o’clock at Pittsburg and all points in the Central zone; seven
o’clock in all points in the Mountain zone; six o’clock in Denver and
five o’clock in San Francisco. As you keep travelling westward you drop
one hour of the clock time in every zone, and as under this system the
earth’s east to west distance is divided into twenty-four such zones,
if you went west entirely around the world you would lose a whole day
of clock time.

If, however, you went around the world from west to east in the same
manner you would gain a whole day.




Where Does the Day Change?


This system of agreeing on fixed places where the hour changes made it
necessary to also fix a point where for the purposes of the calendar
the day also changes. This imaginary north and south line is fixed
upon at 180 degrees west longitude, which would cut the Pacific Ocean
in two. This line makes it possible for a person to travel all day
before approaching this line and then find himself after crossing it
travelling all the next day with the same name for the day of the week.
Thus he could spend all of Sunday travelling toward the International
Day Line, as this is called, and after crossing it spend another
Sunday, which would be the next day, going away from it. This would
give him the novel experience of having two Sundays on successive days.
The same thing would happen if he were travelling to the Day Line on
Monday, Tuesday, Wednesday, Thursday, Friday or Saturday. He would live
through two succeeding days of the same name in the same week, one
right after the other. This would be in going westward.

If you were traveling eastward and crossed the International Day Line
on Sunday at midnight you would lose a day completely out of the week,
for when you woke up the next morning it would be Tuesday.




Why Do We Cook the Things We Eat?


We have several reasons for doing this. The first and most important
reason to us is that the application of heat to food makes it more
easy to digest. Other reasons are that when cooked our food is more
palatable; the process of cooking kills all microbes, which, if taken
into our bodies alive, would give us diseases, and also it is easier
for us to chew food that has been cooked.

[Illustration: WONDERS PERFORMED BY ELECTRIC LIFT MAGNET

This picture shows the construction of a successful electric lift
magnet. This device, by means of magnetic attraction, fastens itself
to practically all kinds of iron and steel without the aid of slings,
cables or chains.]




The Story in a Magnet


What Makes an Electro Magnet Lift Things?

The working parts of an electric lift magnet are as follows:

_A Shell._--This is a steel casting heavily ribbed on the top for
strength, and also to assist in radiating the heating effect from the
coil.

It is usually made circular in shape, the outside rim forming one pole,
while the lug in the center forms the other. The coil fits in between
these poles, thus making a magnet similar to the ordinary horseshoe
type.

_A Bottom Plate._--The under side of the magnet is closed by a very
tough and hard non-magnetic steel plate, in order to protect the coil.

As well as being non-magnetic, this plate also has sufficient strength
to resist the severe wear to which a magnet is necessarily subjected.

_A Terminal Box._--A one-piece heavily-constructed steel casting bolted
to the top of the shell, containing and protecting the brass sockets
into which the wires from the coil terminate, forms the Terminal Box.

The sockets are made to receive plugs placed on the end of the
conductor wire, by which the magnet is connected with the generator.

_A Coil._--This consists of a round insulated wire which is passed,
while being wound, through a cement-like substance, heavily coating
each individual strand.

A low voltage of current is then passed through the coil, a sufficient
length of time, to thoroughly dry out and bake the coating. This
renders the magnet absolutely fireproof, eliminating all danger of
short circuiting of the coil.

When finished it is well taped to protect the outside wire from
becoming chafed.

The coil is made slightly smaller than the inside dimensions of the
shell and the remaining space is filled with an impregnating compound,
which hardens to the consistency of pitch.

This renders the coil thoroughly waterproof; also forms a cushion to
prevent injury from the severe jars and shocks, received when dropping
a magnet on its load.

_A Controller._--The rapidity with which it is necessary to turn
current on and off while operating a magnet, creates what is called a
“back kick.” Unless this is dissipated quickly it is very destructive
to the coil.

A special controller dissipates this back kick through a set of
resistance coils placed in the controller. By means of an automatic
arrangement, connection with these coils is made instantly upon
breaking the current between the magnet and generator.

A system of control used prevents undue heating of the coil. This
enables the magnet to lift as large a load after a long steady run as
at the start.




What Is a Lodestone?


A lodestone is a variety of the mineral named magnetite which is a
natural magnet. The name magnet comes from the name of the mineral
magnetite and this in turn derived its name from the fact that it was
first discovered in Magnesia. The word magnet really means the “Stone
of Magnesia.”

A lodestone is one of the mysteries of nature. Its properties can
more nearly be understood if we examine an artificial magnet, which
is generally made in the form of either a straight bar or a shoe.
An artificial magnet is made of iron. If you drop a bar magnet into
a box of iron filings, the filings attach themselves to the bar. If
you examine it closely you observe that most of the filings attach
themselves to the ends of the bar. Therefore we call the ends of the
bar the poles of the magnet.

If you suspend a magnetic needle at its center of gravity so that it
is absolutely free to turn, you will soon find one end of the needle
pointing north and the other south of course. The end which is pointed
toward the north is called the north pole and the other the south pole.
If you have a horse-shoe magnet, you can demonstrate this for yourself.
Rub the end of your magnet over a sewing needle and oil the needle so
that when you lay it on the surface of a glass of water it will float.
Then look at it closely. You will see the needle slowly turn until
finally it becomes quite still. If you have a compass at hand so that
you know surely which is north and which is south, you will find one
end of the needle pointing north and the other south. You can then
place the end of your magnet against the outside of the glass and draw
the needle toward your magnet. Your horse-shoe magnet has its north and
south poles close together.

If you have a bar magnet and the end of the needle with the eye in it
is pointing north, you can drive the needle on the surface of the water
away from you by touching the outside of the glass opposite that end of
the needle with the north pole of your magnet. On the other hand, if
you reverse the experiment and place the south pole of your magnet to
the side of the glass, the needle will come toward the magnet. In other
words then the like poles of a magnet repel each other and the unlike
poles attract each other.

Another interesting way to show this is to take two lodestones or two
magnets and let a lot of iron filings attach themselves to the ends
of them. Then when you have done this, point the two north poles of
the magnets or lodestones at each other close together. You will be
intensely interested in seeing how quickly the mysterious something
that is in the magnets makes the filings on the two ends of the magnet
try to get away from each other. On the other hand when you put a north
and south pole together, they form a union of the iron filings.

Another strange thing about a magnet is that if you break it in two,
each half will be a complete magnet in itself with a north and south
pole also, and this is true no matter how many times you break it
into pieces. From this we learn that each tiny particle or molecule
throughout the bar is a magnet by itself.

[Illustration: WHAT A LODESTONE IS

This is a picture of a complete electro magnet. The magnet is attached
to the arm of a crane by the loop in the center and when the magnet
then comes in contact with any kind of iron or steel it lifts it as
soon as the current is turned on. By making the electric current
stronger, greater weight can be lifted. Many tons of material can be
lifted at one time. An electro magnet will do the work of many men at
much less cost.]

[Illustration: In this picture we see the magnet lifting a great weight
of miscellaneous pieces of scrap iron. As many as twenty tons can be
lifted and transferred from one place to another at one time.]

Some things can be magnetized while others cannot. Many substances have
not the property of magnetizing other substances when they have once
been attracted by a magnet. These are called magnetic substances. They
remain magnetized only as long as they are in touch with the magnet;
other substances when once magnetized become permanent magnets. Steel
and lodestone have this faculty. A compass needle is an artificial
magnet which becomes a permanent magnet when rubbed with a magnet.




What Is Electricity?


If you pass a hard rubber comb through your hair, in frosty weather, a
crackling sound is produced, and the individual hairs show a tendency
to stick to the comb. After being drawn through your hair a few times,
you may notice that the comb has become charged with electricity. This
electricity is produced by friction. Not only rubber but many other
substances become electrified by friction, such as a bar of sealing
wax rubbed with flannel, or a glass rod rubbed with silk, will show
the same qualities, and these simple experiments teach us many of the
fundamental facts about electricity.

Some simple experiments will be found instructive and interesting. Rub
with flannel a stick of sealing wax until it is electrified and then
bring it close to a pith ball which should be hung by a silk thread.
The pith ball will at once be attracted to the sealing wax, and, if
brought quite close, the ball will adhere to the wax for a few moments,
and then fly away from it. The ball will now be repelled by the sealing
wax instead of being drawn toward it. Now take a glass rod, rub it with
a silk cloth after drying it thoroughly. When the pith ball is brought
close to the glass rod it also will at first be attracted toward the
glass and, if brought in contact with the glass, the pith ball will
adhere as before. It will also then fly away in the same way it did
from the sealing wax. Repeat these experiments with the sealing wax now
and you will find the ball will be attached, as it was at first, but if
it touches the wax it will again adhere for a moment and then fly away.
By using the sealing wax and glass rod alternately and bringing them
into contact with the pith ball, you discover that when it is attracted
by one, it is repelled by the other, and that, after it has been in
contact with either for a few moments it is no longer attracted by it.

We learn thus that the electricity in the glass and the sealing wax
are not the same. To distinguish the two kinds of attraction, we say
the glass is charged with positive, or vitreous electricity, while the
charge on the sealing wax is called negative, or resinous electricity.

When the pith ball was touched with the sealing wax, it became filled
with negative electricity, and was then no longer attracted by the
wax, but was repelled by it and attracted by the glass rod; but when
the ball had been filled with positive electricity, it was repelled by
the glass and attracted by the wax. We conclude from these facts that
bodies filled with the same kind of electricity repel each other, while
bodies filled with opposite kinds of electricity attract each other.

When two substances are charged, as we say, with electricity of
opposite kinds and are brought into contact, and left so for some time,
the two charges disappear, one appearing to neutralize the other. From
this, we conclude, and rightly, that any substance not electrified,
contains equal amounts both positive and negative electricity. When,
therefore, we rub a piece of glass with silk, we are not creating
electricity, but only separating the different kinds. The positive
electricity adheres to the glass, and the negative remains behind,
on the silk. In the same manner, when we electrify sealing wax with
flannel the negative kind remains in the sealing wax and the flannel
becomes charged with the positive. Whenever a body is electrified by
friction, both kinds of electricity are produced; it is impossible to
produce one kind without the other.

[Illustration: WHAT ELECTRICITY IS

Magnets are particularly valuable in lifting raw material in a steel
mill. The red-hot pig-iron, from which steel is made, can be handled
easily in this way, whereas it would be impossible to handle same by
hand. Sometimes great quantities of iron are broken up by the magnet. A
weight of many tons is lifted by the magnet and allowed to fall on the
material to be broken up. The weight falls as soon as the current is
turned off.]

[Illustration:

  Weight of wheel, 8160 lbs.

Pieces of machinery which cannot be lifted by men on account of their
great weight and shape are handled easily.]

You must rub the entire glass rod or bar of sealing wax to electrify
the whole of it. If only a part of the glass rod or sealing wax is
rubbed, only that part becomes electrified, as may be shown by trying
to attract a pith ball with the part that has not been rubbed.

~WHAT GOOD AND BAD CONDUCTORS OF ELECTRICITY ARE~

If, however, the charged part of the sealing wax is brought into
contact with a metal rod resting on, say, a drinking glass, the rod
becomes charged, not only where it is brought into contact, but all
over its surface. Substances over which electricity flows readily
are called conductors of electricity. All metals are of this kind.
Things like glass and sealing wax over which electricity does not flow
readily, are called non-conductors, or insulators. Water, the human
body, and the earth are good conductors and rubber, porcelain, most
resins, and dry air are non-conductors.

You have already learned that substances charged with opposite kinds of
electricity attract each other, and substances charged with the same
kind repel each other. We will try to discover why substances charged
with either kind of electricity attract small light objects, such as
pith balls, when these latter are not charged with electricity. As we
have discovered, all substances which have remained undisturbed have
both kinds of electricity present in them, in equal amounts. Now, when
an uncharged body is brought near a charged body, the two kinds of
electricity in the uncharged body have a tendency to separate. The kind
opposite in character, to that on the charged body, is attracted toward
the charged body, and the other kind is repelled. Thus, if our bar of
sealing wax, charged with, let us say, negative electricity, is brought
near a pith ball, the positive electricity in the ball is attracted
to the side nearest the scaling wax, and the negative electricity
is repelled to the farther side. As the positive electricity on the
pith is nearer to the scaling wax than the negative, its attraction
for the negative charge, on the sealing wax, is stronger than the
repulsion between the negative electricities of the two objects, and
consequently, the ball is attracted to the sealing wax. If the charged
sealing wax is brought near a good conductor, which is supported on
some non-conducting substance, such as glass, silk, or rubber, over
which electricity will not flow, a much more complete separation of the
two kinds of electricity occurs on the conductor than on the pith ball.
If the charged sealing wax is brought near one end of a metal rod so
placed, the charge of negative electricity upon the sealing wax will
attract the positive electricity on the metal, to that end, and will
repel the negative electricity to the other end. When a pith ball, hung
by the silk thread, is brought close to either end of the metal rod,
when the charged sealing wax is near the other end, the pith ball will
be attracted toward the rod; but will not be attracted if placed close
to the middle of the rod. This proves that the metal rod is electrified
only in the parts nearest to and farthest away from the charged body.
The two kinds of electricity neutralize each other at the parts in
between.

If now we take two conductors and place them end to end, we have
for all practical purposes, a single conductor. It has the decided
advantage, however, of being easily separated into two parts. When an
electrified substance is brought close to one end of such a conductor,
a charge of one kind is attracted to the near portion of the conductor,
and a charge of the opposite kind is repelled to the farther part. By
separating the two parts of the conductor, we learn that one of the
ends, which have been in contact, is charged with positive and the
other with negative electricity.

This act of separating the two kinds of electricity upon a conductor by
means of a charge upon another body which is not permitted to come into
contact with the conductor, is called induction, and two charges of
electricity produced in this way are known as induced charges.

There are other ways in which a charge of electricity may be induced
upon a conductor. One end of the conductor may be connected with the
earth by means of some good conducting material, and the charged
substance brought close to the other end. A charge, opposite in
character to the initial charge, is attracted to the end of the
conductor that is near the charged body, and the electricity of the
opposite kind is repelled, through the conductor to the earth. By
securing the connection with the earth, while the charged body is
near the conductor, a charge is obtained upon the conductor, that is
opposite in character to the initial charge. This method of charging
conductors, by induction, is practically the same as the one first
described, for the earth is a conductor of electricity, and corresponds
to the more distant part of the two-piece conductor.

An instrument, known as the electrophorus, is especially designed for
the production of electric charges by induction in the manner just
described. This instrument consists of a brass plate, on an insulating
handle of glass, and a disk of sealing wax, fitted into a brass dish,
whose edges rise somewhat higher than the surface of the wax. In using
the electrophorus the brass dish, or sole, is placed upon some support
that will conduct electricity, and the sealing wax disk is then rubbed
vigorously with a piece of flannel, or catskin, which electrifies the
sealing wax, with negative electricity. The brass plate is then taken
by the glass handle and brought close to the charged sealing wax. The
charge of negative electricity on the wax attracts a charge of positive
electricity to the under surface of the plate and repels a negative
charge to its upper surface. If the charged plate is now brought into
contact with the edge of the brass dish the negative charge, on the
back of the plate, flows away, through the legs of the dish, to the
earth, but the positive charge remains on the under surface, where
it is bound, by the attraction of the negative charge on the disk of
sealing wax. If the brass plate is now removed, it will be found to be
charged with positive electricity.

The negative charge upon the sealing wax is not reduced or diminished
by its action in charging the brass plate, and it is possible to charge
the plate an indefinite number of times by means of one charge on the
sealing wax.

The charges of electricity, produced in any of the ways that have been
described, are necessarily small, and the disturbance produced, when
they are destroyed by bringing oppositely charged conductors together,
is very slight, merely a little snapping noise and, perhaps, a small
spark, that seems to leap from the positively charged conductor to
the negatively charged one, when they come very close together. By
the use of electrical machines of various kinds, in some of which
the electricity is produced by friction, and in others by induction,
conductors may be charged with much larger quantities of electricity,
and the disturbance produced by their discharge is greatly increased.
The noise produced is louder and the spark much brighter, and leaps
from one conductor to the other, while they are much farther apart.
It is possible to produce still larger charges of electricity upon
conductors if they are arranged so as to form what are called
condensers.




What Is a Leyden Jar?


One of the commonest forms of condenser is the Leyden jar, which is so
named because it was invented at Leyden, in Holland. This is a glass
jar, upon the outside of which is fastened a coating of tinfoil, that
covers the bottom of the jar and extends two-thirds of the way up
the sides. Inside the jar there is a similar coating of tinfoil, and
through the top of the jar, which is usually made of wood, extends a
metal rod. On the upper end of the rod, there is a metal ball, and, at
the lower end, is attached a chain which runs down to the bottom of the
jar and rests upon the inner tinfoil coating.

In using the Leyden jar, the ball on the metal rod that runs through
the top of the jar is connected with an electrical machine, and the jar
is supported upon some conducting material, through which electricity
may be conveyed from the outer coating of tinfoil to the earth. If the
inner coating of tinfoil is now charged with positive electricity, by
means of the electrical machine, it induces, upon the outer coating
of foil, a charge of negative electricity, which is bound by the
attraction of the positive charge on the inside of the jar. At the
same time, the positive electricity, on the outer coating of foil, is
repelled, through the conducting support, to the earth.

The charge that can be communicated to the coating of the foil, inside
the Leyden jar, is greatly increased by the presence of a charge of the
opposite kind of electricity, on the coating on the outside of the jar.
Each of these charges attracts the other, through the glass of the jar,
and serves to bind or hold it. If either coating of foil is removed,
the charge on the other coating tends to fly off the tinfoil, and will
immediately do so, if a conductor is brought near. It is because the
negative effects of the initial charge, inside the jar, and of the
induced charge outside the jar, make it possible to communicate, to
each coating of foil, a larger charge than it could otherwise be made
to receive, that a Leyden jar is called a condenser.

When a Leyden jar is disconnected from the electrical machine, two
opposite charges of electricity are present on it, one inside and the
other on the outside. If the two coats of tinfoil are now connected, by
means of a condenser, they will at once neutralize each other, and the
jar will be discharged. A jar may be discharged, by simply taking hold
of the tinfoil on the outside of the jar, with one hand, and touching
the metal rod, running through the top of the jar, with the other.
If you do this, there will be a sudden flow of electricity through
your body, your muscles will give a sudden jerk, and you will feel a
peculiar tingling sensation. In other words, you will have received a
shock.

It is not necessary, for the hand that does not grasp the jar, actually
to touch the rod that runs through the top. If the hand is brought
toward the rod, rather slowly, you will see a spark leap across the
space between the rod and your hand, while your hand is still some
distance from the rod. The greater the distance, across which the spark
leaps, the brighter will be the spark, and the stronger the shock
produced. This distance is sometimes spoken of as the length of the
spark, and it indicates the size of the charges on the tinfoil coatings
of the jar.




Who Discovered Electricity?


It may seem difficult to believe, that the tiny spark and weak snapping
noise that are produced when a Leyden jar is discharged, are, in many
respects, the same as lightning and thunder, but it is nevertheless
true. This was proved by Benjamin Franklin, about the middle of the
18th century, in the following way. One afternoon, when a thunder
shower was approaching, he sent up a kite, to the string of which he
fastened a large metal key; and to the key, a ribbon of non-conducting
silk, which he held in his hand. When the rain had been falling long
enough to wet the string thoroughly, it become a good conductor of
electricity, and Franklin found that the key had become charged with
electricity transmitted from the clouds, along the wet kite string.
The non-conducting silk ribbon, that formed the continuation of the
kite string, from the key to his hand, was employed to prevent him from
receiving shocks from the passage of the electricity, through his body,
to the earth.

Up to this point, your attention has been directed in charges of
electricity. You have been told how they may be produced, what some of
their leading properties are, and what effects they produce, when they
are discharged. The subject that will now be explained to you is that
of electric currents.




What Is an Electric Current?


By an electric current, is meant a flow of electricity along a
conductor. The flow of electricity, through your body, when you receive
an electric shock, is a current, but it lasts only for an instant, and
it is difficult to learn much about its nature. By the use of various
devices, it is possible to produce currents, that will continue as long
as we want them, so that we are enabled to study their properties quite
thoroughly.

One of the oldest and simplest forms of apparatus, for producing
electric currents, is that which is known as the voltaic cell. This
form of apparatus may very easily be constructed. Pour some water into
a glass jar, and add a little sulphuric acid. Now place in the water a
strip of clean zinc and one of clean copper. Do not let the strips of
metal touch in the water, but connect them outside the water by means
of a piece of wire. When this has been done, a current of electricity
will be sent up along the wire and through the water between the two
strips of zinc and copper. This current is said to flow along the wire
from the copper, which is called the positive pole of the cell, to the
zinc, which is called the negative pole. In the liquid in the cell
(i.e., the jar), the current travels from the zinc to the copper, thus
completing what is called the electric circuit. Whenever the circuit it
broken, that is, whenever there is a gap made in the wire connecting
the poles, or anything else is done to destroy the completeness
of the path, along which the current travels, the current ceases;
consequently, when it is desirable to stop the current, all that is
necessary is to cut the wire connecting the two strips of copper and
zinc.

The production of a current of electricity, by means of an apparatus of
this sort, depends upon the chemical action of the acid in the water
upon the strip of zinc. As long as the acid continues to act upon
the zinc, the current is produced, and when the acid ceases to act
upon the zinc, the current ceases to flow. If the zinc is clean, the
chemical action of the acid ceases, whenever the circuit is broken, and
consequently, when the cell is not being used to produce a current,
the zinc is not destroyed by the acid. But if the zinc is not clean,
small electric currents are set up, within the liquid, between the
zinc and the impurities on its surface, and around the points where
these impurities lie the acid acts upon the zinc and dissolves it. This
action of the acid upon the zinc, when the circuit is broken, is known
as local action, and it is very desirable to prevent it, as far as
possible. For this purpose the zinc is often rubbed with mercury, which
soaks into the zinc and forms a film on its surface, upon which the
impurities float. This treatment of the zinc is known as amalgamation,
and it serves to prevent almost all the local action, due to impurities
of the zinc.

Many other substances, besides zinc and copper, have been found capable
of yielding an electric current, when placed in a suitable liquid, and
many other fluids, besides water that contains a little sulphuric acid,
have been employed to act upon the zinc and copper, or the substances
used in their stead. Numerous cells of different kinds have, therefore,
been devised, but, in all of them, the current is produced by chemical
action. Most of them contain a liquid of some sort, which is called the
exciting fluid, and two solid substances, which are called the elements
of the cell. One of these elements is always much more susceptible to
the chemical action of the exciting fluid, than the other, and this one
is known as the positive element. The other element, upon which the
exciting fluid may have no action, is called the negative element. In
cells in which the elements are zinc and copper, the zinc is always the
positive element. This may seem strange to you, for you have already
learned that the zinc is the negative pole of the cell, but, to avoid
confusion, you must fix well in your mind the fact that the zinc is
not the positive element of a voltaic cell, but its negative pole,
and that the copper, which forms the negative element is the positive
pole of the cell. The currents produced by the various forms of voltaic
cells, vary considerably in strength, but none of them are very strong.
In order to obtain a stronger current, a number of cells must be used
together. Such a collection of cells forms a voltaic battery, and in
some instances, as many as fifty thousand cells have been used in a
single battery.

We have already learned in our study of water that it may be separated
into its elementary gases by sending an electric current through it.
The effect is a chemical one. Water, however, is not the only substance
that is decomposed by electricity; almost all chemical compounds may be
decomposed by the passage of a current through them, provided a current
of sufficient strength is used.

Another effect of the current is its heating effect. It has been found
that the passage of an electric current, through any body, is always
productive of a certain amount of heat. The amount of heat produced
depends upon the strength of the current of electricity, and the
resistance to its passage that is offered by the body through which it
travels. This amount is increased by increasing either the strength of
the current or the resistance of the conductor along which it travels.
We have already learned, that some substances allow electricity to
pass over them very readily, and are therefore called conductors,
while substances through which electricity does not flow readily are
known as non-conductors. No substance is a perfect non-conductor, for
electricity can be made to pass through any substance, if the current
is sufficiently powerful. Neither is any substance a perfect conductor,
for all substances offer some resistance to the passage of an electric
current. Those substances that are ordinarily considered good
conductors offer varying degrees of resistance to electric currents.
For example, a copper wire offers less resistance than an iron wire of
the same length and diameter.

The resistance of a body depends not only upon its material, but also
upon its length and size. In conductors of the same material, the
resistance is directly proportional to the length of the conductor,
and inversely proportional to the square of its diameter. This is not
surprising, for an electric current bears a strong resemblance to a
current of water, in many of its properties, and you know that it is
harder to force water through long, narrow pipes, than through short,
wide ones.

From what has been stated about resistance, you may see, that a current
will produce more heat, in passing through a long fine wire, than
through a shorter and thicker one, and that, of two conductors of the
same length and size, but of different material, one may be heated much
more by a current than will another.

~HOW MAGNETS ARE MADE~

A third effect of the electric current, which has not previously been
mentioned is its magnetizing effect. It is upon this, that some of the
most important effects of electricity depend.

By coiling a wire around a bar of iron or steel, and then sending an
electric current through it, the piece of iron, or steel, is made to
show magnetic properties. By this is meant, as you doubtless know, that
the iron will now attract other pieces of iron, or steel, to it. The
strength of this attraction depends upon the strength of the current,
and upon the number of turns of wire around the bar. By increasing
either the strength of the current, or the number of turns in the
coil of wire, around the bar of iron, the strength of its magnetic
attraction is increased. When the current is stopped, the magnetic
properties of the iron disappear almost completely. A magnet, that
depends upon a current of electricity for its magnetic power, is called
an electro-magnet.

Besides electro-magnets there are others, which are called permanent
magnets. Electro-magnets are composed of soft iron, the softer the
better, and, as soon as the current of electricity ceases to flow
around them, their magnetic properties disappear. Permanent magnets,
on the contrary, are made of steel, and their magnetism is independent
of the action of a current of electricity. No coil of wire is wound
around them, and no current is employed to maintain their magnetic
properties. A piece of steel may be made to become a permanent magnet,
by passing a current of electricity, for a considerable time, through
a coil of wire wound around it, or by allowing a piece of steel to
remain for some time in contact with a strong magnet. When a current of
electricity passes through a coil of wire, wound around a bar of steel,
it takes longer to magnetize the steel than it would to magnetize iron,
but, when the current ceases, the magnetism does not all disappear from
the steel. A portion of it remains, and the steel becomes permanently
magnetic.

If a thin bar of steel is magnetized, and is then suspended by its
middle, so that it can spring freely, it will be found that one end
tends to point toward the north, and the other toward the south.
Whenever the bar is swung out of this position, it swings back to it,
and if the north end is turned entirely around to the south, it does
not remain, but swings back to its former position. This shows that
there is a difference in the magnetism at the two ends of the magnet.
To indicate this difference, the north-seeking end of a magnet is
called the positive pole of the magnet, and the south-seeking end is
known as the negative pole.

By suspending two bar magnets, in the manner described, it can be shown
that the positive and negative poles of the magnets act like positive
and negative charges of electricity. Poles of the same kind repel, and
poles of opposite kinds attract, each other.

Permanent magnets are usually made in two forms, either straight
or horseshoe shaped. A compass needle, as has been shown, is an
example of a straight magnet. The horseshoe variety, which has a
little bar of iron, called the keeper, laid across the poles is a
common toy. Electro-magnets are seldom seen, except in electrical
instruments or machinery. The pictures shown on the following pages
give us a bird’s-eye view of some of the wonders performed by these
electro-magnets. Tons and tons of material are picked up and held
securely by one of these magnets as easily as you can hold on to an
apple.




Why Does a Bee Have a Sting?


The bee’s sting is given him as a weapon of defence. Primarily it is
for the sole purpose of enabling him to help defend the hive from his
enemies. Sometimes when he is attacked away from the hive he uses his
sting to defend himself. When he does so, he injects a little quantity
of poison through the sting and that is what causes the inflammation.




How Does a Honey Bee Live?


The bee lives in swarms of from 10,000 to 50,000 in one house. In the
wild state the house or hive is located in a hollow tree generally.
These swarms contain three classes of bees, the perfect females or
queen bees, the males or drones, and the imperfectly developed females,
or working bees. In each hive or swarm there is only one perfect female
or queen whose sole mission is to propagate the species. The queen is
much larger than the other bees. When she dies a young working bee
three days old is selected as the new queen. Her cell is enlarged by
breaking down the partitions, her food is changed to “royal jelly
or paste” and she grows into a queen bee. The queen lays 2,000 eggs
per day. The drones do not work and after performing their duty as
males are killed by the working bees. The female bees do the work of
gathering the honey. They collect the honey from the flowers, they
build the wax cells, and feed the young bees. When a colony becomes
overstocked, a new colony is sent out to establish a new hive under the
direction of a queen bee.




THE BEGINNING OF A STEAMSHIP


[Illustration: Probably no form of construction is so interesting to
everyone as the construction of a huge steamer, a wonderful “city”
afloat, with its thousands of passengers, its thousand officers and
crew, the tremendous stores of provisions and water, and the precision
with which the great ship plows its way from one shore to the other.

This picture shows the first work in building a modern steamer, laying
the keel and center plate, upon which the massive hull is constructed.
The rivets are driven by hydraulic power, noiselessly but firmly. In
the new “Britannic”--largest of all British steamers and the newest
(1915) modern leviathan--over 270 tons of rivets--nearly three million
in all--were required to give staunchness to the steel-plated hull. The
cellular double bottom is constructed between the bottom and top of the
center plate.]

[Illustration: A LONGER VIEW OF THE ABOVE OPERATION.]

[Illustration: THE CRADLE OF A STEAMSHIP CALLED A “GANTRY”

VIEW NEAR THE BOW.

The “ribs” of the “Britannic,” showing the deck divisions, in outline.
The huge “gantry” or cradle of steel, in which “Britannic” was built,
cost $1,000,000.]

[Illustration: THE DOUBLE BOTTOM OF MODERN STEAMSHIPS

THE “BRITANNIC” OF THE WHITE STAR LINE. VIEW OF THE DOUBLE BOTTOM
PLATED.]

[Illustration: THE HUGE STEEL SKELETON OF THE “BRITANNIC” BEFORE THE
PLATES WERE PLACED ON IT.

The plates are seen piled in the foreground. The largest of them are 36
feet long and weigh 4¹⁄₄ tons each.]

[Illustration: THE SHIP READY TO LAUNCH

NOT A “SKYSCRAPER,” BUT A FLOATING HOTEL IN PROCESS OF CONSTRUCTION.

THE HULL ITSELF IS 64′ 3″ DEEP, AND FROM THE KEEL TO THE TOP OF THE
FUNNELS IS 175 FEET. THE NAVIGATING BRIDGE IS 104′ 6″ ABOVE THE KEEL.]

[Illustration:

  WHITE STAR
  ROYAL MAIL STEAMER
  “BRITANNIC”

READY TO LAUNCH.

The “Britannic” on the ways at Belfast (Harland & Wolff’s). The largest
gantries ever constructed to hold a ship.]

[Illustration: THE MACHINERY USED IN LAUNCHING A SHIP

FORWARD LAUNCHING GEAR (HYDRAULIC).

The ship went from the ways into the water in 62 seconds and was
stopped in twice her own length.]

[Illustration: THE HUGE HULL LEFT THE WAYS EASILY AND CREATED ONLY A
SMALL SPLASH.]

[Illustration: A CLOSE VIEW OF A SHIP’S RUDDER

“BRITANNIC” HELD UP JUST AFTER THE LAUNCH.]

[Illustration: “BRITANNIC.” THE 100-TON RUDDER. THE (CENTER) TURBINE
PROPELLER SHAFT AND ONE OF THE “WING” PROPELLER SHAFTS.]

[Illustration: WHAT A SHIP’S PROPELLER LOOKS LIKE

THE COMPLETED SHIP

The center (the turbine) propeller, 16′ 6″ in diameter, cast of one
solid piece of manganese bronze, 22 tons in weight. The “Britannic”
like “Olympic,” is propelled by two sets of reciprocating engines, the
exhaust steam from these being reused in the low-pressure turbine,
effecting great economy in coal. The two “wing” propellers are 23′ 6″
in diameter and weigh 38 tons each.]

[Illustration: WHAT A SHIP’S TURBINE LOOKS LIKE

The turbine motor, 130 tons in weight (Parsons type). The steam plays
upon the blades with such power that they develop 16,000 horse-power
and revolve the propeller (turbine) 165 times a minute. The motor is 12
feet in diameter, 13′ 8″ long, the blades (numbering thousands) ranging
from 18 to 25¹⁄₂ inches in length.]

[Illustration: THE IMMENSE TURBINE MOTOR FULLY ENCASED--WEIGHT 420
TONS.]

[Illustration: HOW A FUNNEL APPEARS BEFORE IT IS IN PLACE

One of the four immense funnels--without the outer casing. Each is 125
feet above the hull of the ship and measures 24′ 6″ by 19′ 0″.]

[Illustration: WHAT A GREAT STEAMSHIP WOULD LOOK LIKE IF SPLIT END TO
END]

This view will give some idea of the interior arrangement of the
huge White Star Line triple-screw steamer “Britannic.” Many features
undreamed of a dozen years ago have been introduced in the passenger
quarters of this ship. As many decks are necessary to provide the
required space for state-rooms, public apartments, promenades, etc.,
several passenger elevators have been installed, which are a great
convenience for those who find the use of stairs irksome. There is
a fully equipped Gymnasium, a children’s Play Room for the younger
passengers, a Squash Racquet Court, a Swimming Pool with sea-water, and
the Turkish Bath establishment.

There are accommodations for over 2500 passengers as well as a crew of
950. The view shows how the ship is divided into numerous water-tight
compartments, so that should several of these sections become flooded
the rest of the ship would remain intact.

The lifeboats, of which there are sufficient to carry all on board, are
handled by a new device, by means of which the boats can be launched,
when filled, with greater ease and safety than hitherto. Each of the
great davits can handle several boats and they are long enough to carry
the boats clear of the side of the ship, should any accident cause her
to list to one side.

The “Britannic” is nearly 900 feet in length, and with her gross
tonnage of 50,000 is the largest British steamer in the world.




What Is Water Made Of?


Every kind of substance in the world is made up of tiny portions, each
of which is distinctly just what the whole mass is, but which are so
small you cannot see them. A pile of sand, or a cupful of sugar or salt
consists of a great many small grains. A cup of water too is made up of
what we would call small grains of water, or what we would call grains
of water if we could think of them in the same way as we do sugar or
salt or sand. These particles are so small that they could not be seen
separately, even if the particles did not have the ability to stick so
close together that we could not distinguish them even if they were
large enough to be seen.

The word used in describing these tiny particles in any substance,
water, sugar, sand, salt or anything else is molecule.




What Is a Molecule?


The word molecule means “smallest mass,” which indicates the very
smallest division that can be made of any substance without destroying
its identity. Every substance is made up of molecules, and in many
cases the molecules of one substance will mix with those of another
substance, while in other cases they will not. When you dissolve sugar
in water or melt lead or change water into steam, the physical body of
the substance is changed, but the molecules remain as they were. They
are only changed in so far as their relations to each other and to
those of another substance are concerned.




How Do We Know a Thing Is Solid, Liquid or Gas?


The relations of the molecules in any substance to each other is what
determines whether a substance is a solid, a liquid or a gas. A gas is
a substance in which the molecules are constantly moving rapidly about
among each other, but always in straight lines. A liquid substance is
one in which the molecules are also constantly moving about but which
do not move in straight lines. Solids are substances in which the
molecules stick together in one position by the power of cohesion which
they have. Cohesion means the power of sticking together.




How Big Is a Molecule?


We do not as yet know all there is to be learned about molecules. We
know through the wonders of chemistry that small as a molecule is, it
is still made up of smaller particles called atoms. An atom is the
smallest division of anything that can be imagined. We have found by
chemistry that even a molecule is capable of being divided, i.e., it
is made up of still smaller particles, but molecules are small enough.
An eminent scientist, Sir William Thomson, has given us probably the
nearest approach to a correct way of saying something of the size of a
molecule. “If a drop of water were magnified to the size of the earth,
the molecules would each occupy spaces greater than those filled by
small shot and smaller than those occupied by cricket balls.”

To get at what water is made of we must separate it through chemistry
into its parts or atoms. When we do this we find that a molecule of
water is made of three atoms or parts. Two of these are exactly alike
and consist of a gas called hydrogen, and the other part is another
gas called oxygen, concerning which gases we have already learned
much in the answers to other questions in this book. In other words,
when we separate water, which is a liquid, into its parts, we change
the relations of the molecules in the water which move in irregular
lines, into parts which move in straight lines and, when the molecules
of a substance, as we have already seen, move in straight lines, the
substance becomes a gas. On the other hand, when you freeze water, it
becomes a solid (ice), and in doing that you fix the molecules in the
water so that they stick to each other.

Men thought for a long time that water was an element like oxygen and
hydrogen, i. e., that its molecules could not be separated in its
parts and was, therefore, considered one of the things which could not
be divided up, but this was due to the fact that it requires a great
amount of power to break up the molecules of water.




What Is an Element?


An element is any substance whose molecules cannot be broken up and
made to form other substances. You can take one or more elements and
make a compound, which is what water is. A compound is a substance in
which the molecules are made up of at least two kinds of elements or
elementary substances.

~THE DIFFERENCE BETWEEN ELEMENTS AND COMPOUNDS~

The things we find in the world are known as either compounds or
elements. An element, as we have already learned, is something in
which the molecules cannot be broken up. A compound is, therefore, a
substance in which the molecules are made of molecules of one or more
elements and is either gas, liquid or solid, according to the relations
which these molecules have to each other. We have so far discovered
less than eighty real elements in the world, although since we find
a new one every little while, there are probably many more as yet
undiscovered.

Not all elements are gases, of course. Solids like copper, gold,
iron, lead and a number of others are elements. Among liquids we have
mercury, and of the gases we find hydrogen, nitrogen and oxygen,
which are the three wonderful gases about which we are about to learn
something, and these three are also the world’s most important gases.
Ammonia is an element, but, while we think of it as a liquid, the real
ammonia is really a gas. Our household ammonia is really a compound of
ammonia with something else.




What Is Hydrogen Gas?


Hydrogen is one of the elementary substances in the form of a gas. It
has no color or taste or odor, so we can neither see, smell nor taste
it. It is the lightest substance known to the world. We have by the aid
of chemistry been able to catch and retain it in sufficient quantities
to weigh it and have found it to be lighter than anything else in
the world. It is soluble in water and some other liquids, but only
slightly so. It refracts light very strongly and will absorb in a very
remarkable manner with some metals when they are heated. It burns with
a beautiful blue flame and very great heat. When burned it combines
with oxygen in the air and forms water. Hydrogen is not poisonous but,
if inhaled, it prevents the blood from securing oxygen, and so the
inhaling of hydrogen will cause death. Hydrogen is not found free in
the air except in small quantities like oxygen and nitrogen and is,
therefore, secured by separating compounds by known methods. It can be
secured by the action which diluted sulphuric acid has on zinc or iron,
by passing steam through a red-hot tube filled with iron trimmings, by
passing an electric current through water and in other ways. Hydrogen
is absolutely necessary to every form of animal or vegetable structure.
It is found in all acids.




What Is Oxygen?


Oxygen was discovered in 1774. It is an elementary substance in
the form of a gas which is found free in the air. It is colorless,
tasteless and odorless and, like hydrogen, cannot therefore be seen,
tasted or smelled. It is soluble in water and combines very readily
with most of the elements. In most cases when oxygen combines with
other things the process of combining is so rapid that light and
heat are produced--this combination is called combustion. Where the
process of combining with other substances acts slowly the heat and
light produced at one time are not enough to be noticed. Where metals
tarnish or rust or animal or vegetable substances decay, the same
thing chemically is taking place as when you light a fire and produce
light or heat--you are making the oxygen combine with the substance
in the material which is burning. When iron is rusting or vegetables
decaying, the action is so slow that no heat or light is produced, but
the result is the same if some outside force does not stop the action.
The fire will burn until everything burnable which it can reach is
burned out, and in the case of the piece of iron rusting, the action
will go on slowly until the whole piece of iron is destroyed--or burned
out. Like hydrogen, no vegetable or animal life can live without oxygen
continually given it. Oxygen will destroy life and will sustain it.

All of our body heat and muscular energy are produced by slow
combustion going on in all parts of the body, of oxygen carried in
the blood after it enters the lungs. In sunlight oxygen is exhaled by
growing plants.

Oxygen is the most widely distributed and abundant element in nature.
It amounts to about one-fifth of the volume of the air belt of the
earth; about ninety per cent of all the weight of water is oxygen. The
rocks of the earth contain about fifty per cent of oxygen and it is
found in most animal and vegetable products and in acids.




What Is Nitrogen?


Nitrogen is the third of the world’s wonderful and important gases.
It is also without color, taste or smell. It will not burn or help
other substances to burn and it will not combine easily with any other
element. It will unite at a very high degree of heat with magnesium,
silica, and other metals. About 7.7 per cent of the weight of the air
is nitrogen, so that it is a very important part of the air we breathe
and it is absolutely necessary in making all animal and vegetable
tissues. When united with hydrogen, it produces ammonia, and with
oxygen one of the most important acids--nitric acid. It is found free
in the air and is thus easily secured. Nitrogen, while very important
to all kinds of life, is known as the quiet gas. It stays quietly by
itself unless forced to combine under great power with other things,
and, even under those conditions, will combine rarely. We find a good
deal of nitrogen in the blood but, while we need the nitrogen which is
found in the blood, it does nothing particularly to the blood or the
rest of the body. The nitrogen which the body uses is valuable to the
body only when found in a compound. This nitrogen which the body needs
is secured through vegetable products such as the wheat from which our
bread is made, and which are said to secure their nitrogen through
the aid of microbes which are able to force the nitrogen of the air
into a compound. Some day perhaps we shall know all there is to know
about nitrogen, which is the least known of these three wonderful and
necessary gases.




Why Are Some Things Transparent and Others Not?


Transparency is produced by the way rays of light go through substances
or not. When light strikes a substance that is almost perfectly
transparent, it means that the rays of light go through it almost
exactly as they come in. We think quickly of glass when we think of
something readily transparent. Water is almost equally as transparent.
When the sunlight is shining on one side of a pane of ordinary window
glass, it causes every thing on that side of the window to reflect the
light which strikes it in all directions. When these rays of light
strike the window pane, they go right through and that is how we are
able to see the trees and grass and everything else through a clear
window pane. The same reason applies also to the water.

Some kinds of window glass (the frosted kind) we cannot see
through--they are not transparent. The surface of a frosted window pane
is so made that when the light rays strike it the rays are twisted and
broken, and do not come through as they entered the glass.

Sometimes the water is almost perfectly transparent. When water is
perfectly clear, it is quite transparent. When you look at or into
water that is not transparent, you will know that there are particles
of solid matter floating about in it which twist and mix the light
rays. If the water is not too deep you can see the bottom sometimes
even when there are some particles of solid substances floating about
in it, but the deeper the water the more of these solid particles there
are generally in it, so that it is impossible in most waters to see the
bottom if the water is deep. In some places, however, the water is so
free from floating particles that the bottom of the ocean can be seen
at quite considerable depths.




Why Is the Sea Water Salt?


All water that comes into the oceans by way of the rivers and other
streams contains salt. The amount is so very small for a given quantity
of water that it cannot be tasted. But all this river water is poured
into the oceans eventually at some point. After it reaches the oceans,
the water is evaporated by the action of the sun. When the sun picks up
the water in the form of moisture, it does not take up any of the solid
substances which the water contained as it came in from the rivers, and
while there is about as much water in the ocean all the time and about
as much also in the air in the form of moisture also, the ocean never
gets fuller; the solid substances from the river waters keep piling
up in the ocean and float about in the water there. The salt which is
in the river water has been left behind by the sun when it evaporated
the water in the ocean for so long that the amount of salt has become
very noticeable. The moisture which the sun takes into the air from
the ocean is eventually turned back to the earth again in the form of
rain. This process of evaporation and precipitation in the form of rain
is going on all the time. When the water which is in the form of rain
strikes the earth, it is pure water. It sinks into the ground and on
the way picks up some salt, finds its way into a river sooner or later,
and then evidently gets back into the ocean. All this time it has been
carrying the tiny bit of salt which it picked up in going through the
ground. But when it reaches the ocean again and is taken up by the
sun, it leaves its salt behind and so the salt from countless drops of
water is constantly being left in the ocean as it goes up into the air.
This has been going on for countless ages and the amount of salt has
been increasing in the ocean all the time, so that the sea is becoming
saltier and saltier.




Why Does Salt Make Me Thirsty?


The blood in our body contains about the same proportion of salt as the
water in the ocean normally. When the supply is normal we do not feel
that we have too much salt in our systems, but when you take salt into
your mouth the percentage of salt in the body is increased, and the
being thirsty, or the desire to drink water afterwards is caused by the
demand of the human system that the salt be diluted. The system calls
for water or something to drink in order that it may counteract the too
great percentage of salt in the system. Other things also, when taken
into the body in too great a proportion, cause us to become thirsty.
Thirst is merely nature’s demand for more water on account of the
necessity of reducing the percentage of some substance like salt, or
merely a necessity for having more water in the body.




What Are Diamonds Made Of?


We learned the definition of an element in our study of water and
other substances. Many things which were at one time thought by our
wisest men to be elements were later found to be compounds of other
substances. Water is one of these which we have learned is really not
an element at all, but compounded from two gaseous elements, hydrogen
and oxygen.

One of the most important elements in the world is the one out of
which diamonds are formed. Not because diamonds are so valuable, but
because the element referred to, carbon, is found in every tissue of
every living thing, both animal and mineral. This carbon is one of the
most useful of all elements, but is found in and used by living things
always in combination with some other substance. Carbon is combustible,
forming carbonic acid gas, from which the earth’s vegetation secures
its necessary carbon, which is very great in amount.

When heat is made to act in certain ways on the tissues of animal and
vegetable life we get charcoal, lampblack and coke. Carbon will combine
with more other substances than any of the other known elements. Its
wonders lie in the fact that under various treatments it produces
altogether different looking things, although remaining as pure carbon.
Our diamonds, for instance, are pure carbon, but our lead pencils,
that is, the part we write with, are also pure carbon, and the coal
we burn is carbon also. It would be hard to say which of these three
forms of pure carbon is most valuable to the world. A great many rich
people might say diamonds, while the poor people would surely say
coal, especially if you asked them in winter, while the people who
write books, and newspaper reporters, would probably say lead-pencils.
However, it would be better to choose diamonds, for if you have them
you can always trade them for coal or lead-pencils. A very small
diamond will buy quite a lot of either coal or lead-pencils. Carbon is
one of the solid elements which are not metals. A great many of the
important elements in the group of solids are metals.




What Causes Dimples?


A dimple is a dent or depression in the skin on a part of the body
where the flesh is soft. The fibers which lay in the tissue under the
outside skin help to hold the skin firm. These fibers which are, of
course, small run in all directions and are of different lengths. Now
and then these fibers will just happen to grow short in one spot or the
other and pull the skin in, forming a little depression, but producing
a very pleasing effect.




Why Does the Dark Cause Fear?


Fear is an instinct. We are by nature afraid of the things we do not
know all about. That is why knowledge is so valuable; when we know
about a thing we are sure of our ground. When we are where it is light
we can see what is there; when it is dark our imagination becomes
active and because we do not know for certain what is there in the dark
before us, we imagine things.

Fear of the dark, however, cannot be said to be entirely natural. It
comes naturally only when we have come to the age when we begin to
imagine things. Animals have no imaginative powers and they do not fear
the dark. Some people say that the fear of the dark is bred in us,
but little babies do not fear the dark. If they are properly trained
they will go to sleep in the dark and will prefer the dark. As they
grow older children begin to fear the dark, but that is because their
imagination is coming to life and because parents so often make the
mistake at this stage of training their children of either encouraging
the feeling of fear that darkness brings for the convenient means of
punishment it provides through threatening to put the light out, or
because they do not take the pains to show that there is no reason for
fear.

Most children who fear the darkness are really taught to do so
permanently by parents or servants. When a boy or girl first begins to
imagine things in the dark, many parents run quickly to the child and
say, “Don’t be afraid” or “There is nothing to be afraid of,” and in
doing this they perhaps mention the word “fear” for the first time.
Repetition of this will always cause the child to associate the word
“fear” with “darkness.” As a matter of fact when the boy or girl first
shows fear of the darkness, parents should go to them and quiet their
fears, but talk about anything else but fear and direct the child’s
mind away from any thought of fear.

[Illustration: ANCIENT EGYPTIAN ROPE.]




The Story in a Coil of Rope


How many have ever given a thought to the question of where rope comes
from and how it is made, or realize what a variety of uses it is put
to, and how dependent we are upon it in many of the everyday affairs
of life? But let us suppose for a moment that the world were suddenly
deprived of its supply of this very commonplace material, and of its
smaller relatives, cords and twine. We should then begin to realize
the importance of a seemingly unimportant thing, and to appreciate the
difficulty in getting along without it.

Ancient civilized peoples had their ropes and cordage, made from
such materials as were available in their respective countries. The
Egyptians are said to have made rope from leather thongs, and our
illustration will be found interesting in this connection. This is from
a sculpture taken from a tomb in Thebes of the time of the Pharaoh of
the Exodus.

[Illustration: EGYPTIANS MAKING ROPE.]

While this scene is said by the best authority to represent the
preparation of leather cords for use in lacing sandals, it has been
supposed by some to be a representation of rope making. In any event
the process is undoubtedly the same as that used in making rope.

The scene is depicted with the true Egyptian faculty for showing
details, making words almost unnecessary to an understanding of their
pictorial records. We see the raw material in the shape of the hide,
and also two well-made coils of the finished product. One of the
workmen is cutting a strand from a hide by revolving it and cutting as
it turns. Any one who has not tried it will be surprised to see what a
good, even string can be cut from a piece of leather in this way.

Another man is arranging and paying out the thongs to a third, who is
evidently walking backward in time-honored fashion, twisting as he goes.

Coming down to more recent times we find that rope-making had been
going on for centuries with probably very little change, up to the time
of the introduction of machinery and the establishment of the factory
system.

[Illustration: HACKLING.]

~HOW ROPE WAS LONG MADE BY HAND~

In the early days to which we have referred, all the yarn for
rope-making was spun by hand in the time-honored way. We are able to
represent to our readers by the photographs shown, this now almost lost
art. The material shown in the pictures is American hemp, which because
the earlier machines were not adapted to working this softer fiber,
continued to be spun by hand long after manila was spun chiefly on
machines.

[Illustration: NATIVE PHILIPINO SCRAPING THE FIBER FROM THE LEAF STOCK.]

The hemp was first hackled, as is also shown by our photograph, the
hackle or “hechel” being simply a board having long, sharp steel teeth
set into it. This combed out the tow or short, matted fiber, leaving
the clean, straight hemp. This “strike” of hemp the spinner wrapped
about his waist, bringing the ends around his back and tucking them
into his belt, thus keeping the material in place without knot or
twist, and allowing the fibers to pay out freely.

[Illustration: DRYING THE FIBER.]

[Illustration: SCENE IN AN EGYPTIAN KITCHEN SHOWING USE OF A LARGE ROPE
TO SUPPORT A SORT OF HANGING SHELF.]

The workman in our picture is Johnny Moores, an old-time expert
hand-spinner, who can walk off backward from the wheel with his wad of
hemp, spinning with each hand a thread as fine and even as can be asked
for. In the photograph, in order to show the process more clearly, one
large yarn is being spun.

[Illustration: AN OLD FASHIONED ROPE WALK

HAND SPINNING.]

The large wheel, usually turned by a boy, is used to convey power to
the “whirls,” or small spindles carrying hooks upon which the fiber
is fastened. These whirls, revolving, give the twist to the yarn as
the spinner deftly pays out the fiber, regulating it with skillful
fingers to preserve the uniformity and proper size of the yarn. As he
goes backward down the long walk through the “squares of sunlight on
the floor” he throws the trailing yarns over the “stakes” placed at
intervals along the walk for the purpose.

The spinning “grounds” were usually arranged with wheels at either
end, so that spinners reaching the farther end, could go back to their
starting point spinning another set of yarns.

Then in the case of small ropes, the strands could be made by attaching
two or more yarns to the “whirl” and twisting them together, reversing
the motion to give the strands a twist opposite to that given the
yarns. These strands were twisted together, again reversing the motion,
making a rope. Thus it will be seen that, reduced to its lowest terms,
rope-making consists simply of a series of twisting processes. The
twisting of the yarns into the strand is known as “forming” or putting
in the “foreturn.” The final process is “laying,” “closing” or putting
in the “after turn.” Horse-power was used in old times for forming and
laying rope which was too large to be made by hand.

How all this work is now done in a modern rope factory by ingeniously
devised machinery we shall now see.

The opening room where the fiber is made ready for the preparation
machinery is a reminder of the days when all rope-making processes
were hand work. The bales are first opened up--in the case of Manila
this means cutting the straw matting put on to protect the fiber in
shipment. Then the hanks which are packed in various ways--sometimes
doubled, sometimes twisted--are taken out and straightened and the band
at the end of the hank removed.

No machinery has yet been perfected for doing the work just described
but the first of the preparation processes, a short step beyond, tells
quite a different story. Here the hanks of such fibers as require a
special cleaning treatment are placed on fast working hackling machines
which comb away most of the snarls, loose tow and dirt.

At this point hard fibers--Manila, Sisal and New Zealand--are usually
oiled to soften them and to make them more workable for the operations
that follow. The oil, furthermore, acts as a preservative. It is a
matter of importance to the buyer, however, that the fiber should not
be too heavily oiled, for that merely increases the weight and cost of
the rope without improving its quality.

The wonder of modernism in rope-making is nowhere more striking than
in the preparation room. To pass from one end, where the raw hemp is
received just as it left the hands of the native Filipino laborer with
his crude methods, down through the long rows of machines to the draw
frames from which the sliver is delivered in a form that can be likened
to a stream of molten metal, is to cover decades of inventive genius
and mechanical development.

The mechanism performs its work so accurately that at first glance the
man feeding the fiber into the machine and all the other men, busy
about their various duties, would appear to be playing very minor parts
in modern rope making. In reality, expert workmanship and watchfulness
are very important factors. Good rope depends no more upon scientific
machine processes than upon ceaseless attention to the little details,
and this is especially true in the preparation room.

Before taking up the distinctly modern machines so largely used now
in the final processes of rope-making--the forming of strands, laying
of common ropes and closing of cable-laid goods--we will describe the
rope-walk where much of this work is still best carried on.

[Illustration: HUGE BALES OF RAW ROPE MATERIAL

MANILA HEMP IN WAREHOUSE.]

For making tarred goods in all but the smaller sizes the walk has
certain advantages not afforded by newer methods. It also provides
efficient equipment for turning out the largest ropes, which would
otherwise require special machinery.

[Illustration: A MODERN ROPE WALK

INTERIOR OF ROPE WALK, PLYMOUTH CORDAGE CO.]

The long alleys or grounds where the work takes place are usually laid
out in pairs, one for forming, the other for laying and closing. Each
ground has a track to accommodate the machines used and an endless
band-rope which conveys the power.

[Illustration: NEAR VIEW OF MACHINE IN ROPE WALK.]

~HOW ROPE IS FORMED AND TWISTED~

At the head of the forming ground stand frames holding the bobbins of
yarn. The yarns for each strand first pass through a plate perforated
in concentric circles. This arrangement gives each yarn the correct
angle of delivery into a tube where the whole mass gets a certain
amount of compression.

As the top truck is forced ahead by the twisting process, the ropemaker
by means of greater or less leverage on the “tails”--the loose ropes
shown in our picture--preserves a correct lay in the rope. The stakes
on which the strands rest are removed one by one to allow the top truck
to pass, and then replaced to support the rope until the laying is
finished and the reeling in of the rope begun.

The closing process on cable-laid goods is like the laying except
that the twist is reversed. The work now being with three complete
ropes--frequently very large--a heavier top truck is necessary, and
this must often be ballasted, as shown in our illustration, to keep
down the vibration which would otherwise tend to lift the truck off the
track.

[Illustration: NEAR VIEW OF MACHINE IN ROPE WALK.]

Modern rope-making ingenuity reaches its high-water mark in the
compound laying-machine where the two operations of forming the strands
and laying them into a rope are combined. Up to a certain point this
method is more economical than that in which the forming and laying are
unconnected. Fewer machines are required for a given output--hence,
less floor space and fewer workmen. The time-saving element also enters
in.

[Illustration: PREPARING THE FIBER IN ROPE MAKING

OPENING BALES OF MANILA FIBER FOR PREPARATION.]

[Illustration: PREPARATION ROOM.

Here the fiber is carefully cleaned and combed by a series of fine
tooth machinery through which it passes.]

[Illustration: COUNTLESS SLIVERS STREAM FROM THE ROPE MACHINE

FORMATION OF SLIVER--FIRST BREAKER.

The hanks of fiber are fed by hand into this machine several at a
time, where it is grasped by steel pins fitted to a slowly revolving
endless chain. A second set of pins moving more rapidly draws out the
individual fibers and combs them into a continuous form.

The operations which follow are very similar. A number of “ropings”
are allowed to feed together into a first slowly revolving set of pins
and are drawn out again by a high speed set into a smaller sliver, the
pins becoming finer on each succeeding machine until the draw frame is
reached. Here the fiber is pulled from a single set of pins between two
rapidly moving leather belts called aprons. On all of these machines
the fiber passes between rollers as it goes onto and leaves the pins
and the sliver is given its cylindrical form by being drawn through a
circular opening.

A finished sliver must conform to the special size desired for
spinning.]

[Illustration: SPREADER.]

[Illustration: SECOND BREAKER.]

[Illustration: DRAW FRAME.]

[Illustration: A ROPE MACHINE THAT IS ALMOST HUMAN

FOUR-STRAND COMPOUND LAYING-MACHINE.]

The compound laying machine must, however, be stopped each time that
the supply of yarn on any bobbin is so low as to call for a fresh one.
This would occur so frequently in the case of the larger ropes as to
offset the advantages just mentioned, hence the machine is used on a
limited range of sizes only.

As can be seen in the picture, the machine contains a vertical
shaft with upper and lower projecting arms which support the
bobbin-flyers--four in number in this particular case. The bobbins
within each flyer turn on separate spindles, allowing the yarns to pass
up through small guide plates and thence into a tube.

Each flyer is geared to revolve on its own axis, thus twisting its set
of yarns into a compact strand. At the same time all the flyers revolve
with the main shaft in an opposite direction and form a rope out of the
strands as the latter come together in a central tube still higher up.

The rope is drawn through this tube by a series of pulleys which exert
a steady pull and so keep the proper twist in the rope. From these
pulleys the finished product is delivered onto a separately-driven
coiling reel, an automatic device registering meanwhile on a dial the
number of fathoms run.

The small reel, seen near the head of the main shaft, holds the small
heart rope which is fed into the center of certain four-strand ropes to
act as a bed for the strands.

Pure Manila rope is the very best and the most satisfactory for all
around use. The character of good Manila fiber is such as to impart to
a properly made rope such necessary factors as strength, pliability,
and wearing qualities.

Regular 3-strand Manila rope is universally used for all general
purposes.

For certain special uses, however, and particularly where the rope is
to be used for any kind of sheave work, a 4-strand type of construction
will be found the most suitable, as such a rope presents a much firmer,
rounder, and greater wearing surface than the ordinary 3-strand. There
are many different types of 4-strand rope.

The picture shown on this page represents a coil of 4-strand Manila
called “Best Fall.” This rope is made of carefully selected fiber;
is 4-strand with heart, and is harder twisted than ordinary goods.
Best Fall is adapted for heavy hoisting work, as on coal and grain
elevators, cargo and quarry hoists and for pile-driver hammer lines.

~AN AVERAGE COIL OF ROPE--1200 FEET~

The standard length coil of rope is 1,200 feet, although extra long
lengths are every day made for such purposes as oil-well drilling, the
transmission of power, etc., etc.

[Illustration: SECTION, CROSS SECTION AND COIL, FOUR AND THREE-FOURTH
INCHES CIRCUMFERENCE. SECTION AND CROSS SECTION ONE-HALF ACTUAL]

[Illustration: DIFFERENT KINDS OF KNOTS

KNOTS.

From Knight’s American Mechanical Dictionary.

   1. Simple over hand knot.
   2. Slip-knot, seized.
   3. Single bow-knot.
   4. Square or reef knot.
   5. Square or bow-knot.
   6. Weaver’s knot.
   7. German or figure-of-8 knot.
   8. Two half-hitches, or artificer’s knot.
   9. Double artificer’s knot.
  10. Simple galley-knot.
  11. Capstan or prolonge knot.
  12. Bowline-knot.
  13. Rolling-hitch.
  14. Clove-hitch.
  15. Blackwall-hitch.
  16. Timber-hitch.
  17. Bowline on a bight.
  18. Running-bowline.
  19. Catspaw.
  20. Double running-knot.
  21. Double-knot.
  22. Sixfold-knot.
  23. Boat-knot.
  24. Lark’s head.
  25. Lark’s head.
  26. Simple boat-knot.
  27. Loop-knot.
  28. Double Flemish knot.
  29. Running knot, checked.
  30. Croned running-knot.
  31. Lashing-knot.
  32. Rosette.
  33. Chain-knot.
  34. Double chain-knot.
  35. Double running-knot with check-knot.
  36. Double twist-knot.
  37. Builder’s knot.
  38. Double Flemish knot.
  39. English knot.
  40. Shortening knot.
  41. Shortening knot.
  42. Sheep-shank.
  43. Dog-shank.
  44. Mooring-knot.
  45. Mooring-knot.
  46. Mooring-knot.
  47. Pig-tail, worked on the end of a rope.
  48. Shroud-knot.
  49. Sailor’s bend.
  50. A granny’s knot.
  51. A weaver’s knot.]

[Illustration: HOW TO SPLICE A ROPE

ENGLISH SPLICE.

For transmission rope.

The successive operations for splicing a 1³⁄₄-inch rope by this method
are as follows:

1. Tie a piece of twine (9 and 10, figure 6) around the rope to be
spliced, about six feet from each end. Then unlay the strands of each
end back to the twine.

2. Butt the ropes together, and twist each corresponding pair of
strands loosely, to keep them from being tangled, as shown (_a_) figure
6.

3. The twine 10 is now cut, and the strand 8 unlaid, and strand 7
carefully laid in its place for a distance of four and a half feet from
the junction.

4. The strand 6 is next unlaid about one and a half feet, and strand 5
laid in its place.

5. The ends of the cores are now cut off so they just meet.

6. Unlay strand 1 four and a half feet, laying strand 2 in its place.

7. Unlay strand 3 one and a half feet, laying in strand 4.

8. Cut all the strands off to a length of about twenty inches, for
convenience in manipulation. The rope now assumes the form shown in
_b_, with the meeting-points of the strands three feet apart.

Each pair of strands is now successively subjected to the following
operations:

9. From the point of meeting of the strands 8 and 7, unlay each one
three turns; split both the strands 8 and 7 in halves, as far back as
they are now unlaid, and “whip” the end of each half strand with a
small piece of twine.

10. The half of the strand 7 is now laid in three turns, and the half
of 8 also laid in three turns.

The half strands now meet and are tied in a simple knot, 11 (_c_)
making the rope at this point its original size.

11. The rope is now opened with a marlin-spike, and the half strand of
7 worked around the half strand of 8 by passing the end of the half
strand through the rope, as shown, drawn taut, and again worked around
this half strand until it reaches the half strand 13 that was not laid
in. This half strand 13 is now split, and the half strand 7 drawn
through the opening thus made, and then tucked under the two adjacent
strands as shown in _d_.

12. The other half of the strand 8 is now wound around the other half
strand 7 in the same way. After each pair of strands has been treated
in this manner, the ends are cut off at 12, leaving them about four
inches long. After a few days’ wear they will all draw into the body of
the rope or wear off, so that the locality of the splice can scarcely
be detected.]




Why Do We Go to Sleep?


First, of course, we sleep to rest our body and brain. During our
waking hours many, if not all, parts of our bodies are active all the
time, and with every movement we exhaust or spend some of our strength.
Take the case of your arm, for instance. You may be able to move it
up and down fifty or a hundred or more times without getting tired,
according to how strong you are, but sooner or later you will not be
able to move it any more--it is tired--the life has all gone out of it
and it needs rest, in order that it may become strong again. Every time
you move your arm you destroy certain parts of its tissues, which can
only be replaced during rest. Every activity of your body has the same
experience, and the constant work of the brain in directing the various
movements and activities of the body, tires it out too. As soon as this
condition occurs, the brain tells the other parts of the body that it
is time to rest, and even if we try to keep awake and go on with our
work or play, or whatever it is we are doing, we find sooner or later
that it is impossible. If we persist we fall asleep wherever we happen
to be. It is not necessary for all parts of the body to be tired before
we sleep. One part alone may be so affected by what it has been doing
that it alone causes us to fall asleep. Sometimes the eyes become so
tired, while we are looking at the pictures in a book or reading, for
instance, that we fall off to sleep quickly. It is perhaps easier to
bring on sleep by making the eyes tired than in any other way. That
is why so many people read themselves to sleep. It is such a gradual
passing into unconsciousness that you can hardly ever tell where you
left off reading. It is said that when we are awake our bodies are
continually planning for the time when we shall need sleep and are
continually making some little germ which is carried to the brain as
soon as made, and when there are a sufficient number of these little
germs piled up in the brain, we go to sleep. The process of sleeping
then destroys these germs, and when they are destroyed we again wake up.




Why Do We Wake Up in the Morning?


To answer this we must go back to the answer to the question, “What
makes us go to sleep?” We go to sleep in order to secure the rest which
our body and brain need to build up the parts which have been destroyed
during our active work or play.

We wake up naturally when we have had sufficient rest. We wake up
naturally, however, only when the destroyed parts of the body have
been replaced. Other things may waken us--a noise of any kind, loud
or slight, a startling dream or a moving thing that disturbs our
sleep--according to how fully we are asleep. It is said that sometimes
only parts of the body are asleep; that we are not always all asleep
when we appear to sleep, and that we dream because some part of the
body is awake or active. This is probably true. Now then, when all of
anyone of us is sleepy, we go into what is called a deep sleep and
at such times only something out of the ordinary would awaken us.
Gradually, however, various parts of the body become rested and they
are said to wake up, and finally when all of us is rested, we naturally
wake up all over. If you are healthy and sleep naturally, in a place
where you cannot be disturbed by noises or movements of others, you
should be “wide awake” when your eyes open and be ready to get up at
once. If you feel like turning over for another snooze, when it is time
to get up, you did not go to bed as early as you should have done,
or else some part of you did not get the required amount of sleep it
should have had.




Where Are We When Asleep?


We are just where we lie. It seems to us, of course, because of our
dreams when we are asleep that we are away off some place else. Often
when we wake up we wonder for a minute or two where we are, as
everything seems so strange to us, and it takes a minute or so for us
to remember that we are in our own bed, if that is where we went to
sleep. This is because of the dreams we have while asleep. In past
times the uncivilized savages in various parts of the earth believed
that when any of them went to sleep that the real person so asleep
actually went away, leaving the body behind; in other words, that
the soul went traveling. They thought this because it was the only
explanation they could think of for the dreams they had, since almost
invariably the dream was about some other place.




Why Does It Seem When We Have Slept All Night That We Have Been Asleep
Only a Minute?


This is because all our ideas of passage of time are based on our
conscious periods. When we are asleep we are unconscious. It is the
same as if time did not pass, and when we wake up the tendency is to
start in where we left off. We have learned by experience that when
we go to sleep at night and wake up in the morning that much time has
passed and this unconscious knowledge keeps us from thinking always
that we have been asleep but a minute. But if you drop asleep in the
day time, no matter how long you sleep, you wake up thinking that
you have been asleep only a minute, and sometimes it is difficult to
convince yourself that you have been asleep at all. Sometimes after
being asleep for hours, your first waking thought is a continuation of
what your mind was on when you went to sleep. The reason for this, as
stated above, is that we cannot keep track of passing time when we are
asleep, because we are perfectly unconscious.




Why Should We Not Sleep With the Moon Shining On Us?


There is no harm in letting the moon shine on us while we are asleep.
This is one of the queer superstitions that has developed in the world.
A great many people think that something terrible will happen if the
moon is allowed to shine into the room where they are asleep. Not so
many believe this as used to do so, thanks to the more enlightened
condition of things in the world.

To prove to yourself that no harm can come to you through the moon
shining into your bedroom or upon you as you are asleep, you have only
to remember that a great many men and very many more animals sleep out
under the sky every night and that the moon must shine on them while
they are asleep. As a matter of fact, people who sleep out under the
open sky are generally in possession of more rugged health than people
who sleep in beds in closed rooms. So it is rather better to let the
moon shine on you while asleep than not.

This belief probably started with some one who had trouble in going to
sleep with the moon shining on him, because the light of the moon might
have a tendency to keep him awake. It is easier to go to sleep in a
dark room than in one that is lighted, because when there is no light
there is less about you to keep you awake.




What Makes Us Dream?


Dreams originate in the brain. The brain has many parts and some parts
of it may be asleep while others are not. If all parts of the brain
are actually asleep, it is said there can be no dreams. We have dreams
about things which seem very natural while we are having them, and
which we know would be impossible if we were wholly awake, because
those parts of the brain which control the other parts are probably
asleep while the dream is taking place, and it is then that we have
those fantastic and highly imaginative dreams, for the brain is not
under control in every sense.

We used to believe that dreams have no purpose, just as now we know
that they have no meaning. But it has been discovered that dreams
have a purpose in that they protect our sleep. You see, every dream
is started by some disturbance or excitement of the body or mind.
Something may be pressing or touching us while we sleep, or a strange
sound may start a dream, or perhaps it is some uncomfortable position
in which we are lying or trouble in the stomach on account of eating
something we should not. Whatever it may be, those things wake up some
part of the brain, because if all parts of the brain were asleep, we
could not feel or hear anything. Any such disturbance or excitement
would naturally excite the whole brain and wake us up completely if it
were not for dreams. The dream takes care of this and enables the rest
of the body and brain to sleep while one or more parts of the brain are
disturbed and even perhaps awake. We may perhaps have become uncovered
in some way. This would produce a cold feeling and might wake a part
of the brain and cause a dream about skating or some other winter
amusement or experience, or even perhaps one about falling through the
ice, and still we might not be uncovered so much that it would make any
great difference. The dream comes and we go on with our sleep without
waking up, whereas if it were not for the dream we would awaken. In
other words, dreams are just another wise provision of nature which
enables us to go right on and get the rest we need, even if our
digestion is out of order, or some part of our brain is disturbed
through something we read about, or were told of, or we thought of
while still awake.




Why Do We Know We Have Dreamed When We Wake Up?


Because we remember some of our dreams. Sometimes we do not remember
the dreams we dreamed. This is just like what happens when we are
awake. We remember some things and forget others.

Dreams are a sort of safety valve in our sleep. We dream because not
all of our brain is asleep at the time and it is a wise provision of
nature that permits the waking part of the brain to go on working
without disturbing the sleep of the other parts of the brain. If a
large part of the brain is awake and engaged in making the dream,
we are very apt to remember the dream; but when we dream and cannot
remember what the dream was, it is because only a very small portion of
the brain was awake and making a dream.




What Causes Nightmare?


A nightmare is a dream of what we might call a vigorous kind. A
nightmare is caused by a feeling of intense fear, horror, anxiety
or the inability to escape from some great danger. A nightmare is
the result of either an irregular flow of blood to the brain or by a
stomach that is not in proper condition.

The name for this kind of a dream comes from the words night and mare.
The latter word in one of its several meanings indicates an incubus or
evil vision, and a dream of an evil vision involving fear or horror
came to be termed a mare. Since they occurred generally at night, since
most people sleep at night, they became known as nightmares. Nightmares
are more common to children than grown-up people because children are
more apt to have an uneven flow of blood to the brain and also are more
apt to eat the things which put the stomach in a state of unrest which
causes nightmares. Grown-up people are more likely to have learned to
avoid the abuses of the stomach which are apt to produce nightmares.




What Are Ghosts?


The idea of ghosts is the result of a mistake of the brain or an
attempt to account for something of which we see the results, but have
no actual knowledge. There are no ghosts. There are many forces at work
in the world of which we know nothing as yet. Many of the wonderful
things that occur in the world are as yet mysteries to the mind of
man. Every little while man discovers one of these new forces, and
then he is able to understand many things plainly which were up to
then surrounded with mystery and in the minds of superstitious people
attributed to spirits or ghosts. Long before we understood as much as
we do now of the workings of electricity (and they say we know only a
little of its wonders as yet) many of the natural wonders produced by
electricity were attributed to ghosts.

Most of the marvelous tales of the wonders performed by and visits from
ghosts are the result of disturbances of the brain in the people who
think they see the ghosts and the results of their work.

A creature without imagination does not pretend to see or believe in
ghosts. Man is the only animal which possesses the ability to imagine
things and so the ghosts we hear about are the creatures of the
disturbed brains of men. Generally in the ghost stories we hear of,
the ghost is described as wearing clothes--usually white. A bed sheet
thrown over the foot of the bed may appear to a half-awake person as
the outline of the figure of a ghost and to one of a highly imaginative
temperament without the courage of investigation, become forever a real
ghost. Usually what is supposed to be a ghost is only a creation of
the mind--a vision such as we can develop during a dream--oftentimes,
however, what you look at when you think you see a ghost is an actual
something such as the sheet referred to, but which takes the form of
the ghost in the brain of the person who is looking at it through eyes
that really see it, but out of a brain that for the moment at least is
far off its balance.




Why Do Girls Like Dolls?


Girls like dolls because they come into the world for the purpose of
becoming mothers and the love which they display for dolls is the
mother instinct which begins to show itself early in life. To the
little girl the doll is a make-believe child. It satisfies her as long
as there are no real babies to take its place, but any little girl will
drop her dollie if she is given an opportunity to play at dolls with a
real live baby instead. This is a very interesting fact in connection
with the human race. Boys sometimes play with dolls, but not so often,
and any kind of a boy will give up playing with a doll as soon as a
toy engine or some other boy’s toy appears for him. A boy has certain
mannish instincts which a girl has not. We have many other instincts
besides the instinct of parenthood and each of them has its origin in
some certain kind of feeling which is born within us and is capable of
development along interesting lines.




What Makes the Works of a Watch Go?


A watch like any other machine which we have, only goes when power is
applied in some form or another. In the case of a watch it is a spring.
A spring is an elastic body, such as a strip of steel, as in the case
of the watch, coiled spirally which, when bent or forced out of its
natural state, has the power of recovering its shape again by virtue of
its elastic power. The natural state of a watch spring is to be open
flat and spread out to its full length. When you wind a watch you coil
this spring, i.e., you bend it out of its natural shape. As soon as you
stop winding the spring begins to uncoil itself, trying to get back to
its natural shape, and in doing so makes the wheels of the watch which
operate the hands go round. The spring then, or rather its elasticity,
which always makes an effort to get back to its natural state, is the
power which makes the watch go. Men who make watches arrange the spring
and the other machinery in the watch in such a way that it will uncoil
itself only at a certain rate of speed. Sooner or later the spring
loses its elasticity and then its power to make the watch go.




What Makes a Hot Box?


When you put oil on the axle, however, the oil fills up the hollows
between the little irregular bumps on both the axle and the hub, and
makes them both smooth--almost perfectly so. This reduces the friction
and keeps the axle and hub from becoming hot and expanding. The less
friction that is developed, the more easily the wheel will turn.

[Illustration]




The Story in a Moving Picture


How Are Moving Pictures Made?

To begin at the beginning, we must start with the negative stock,
or film on which the pictures are taken. This material is very much
like the films you buy for the ordinary snap-shot camera, slightly
heavier and of more durable quality, to stand the wear and tear of
passing through the picture camera and the projecting machine used in
exhibition. This film is 1³⁄₈ inches wide and comes in rolls of 200
feet in length. This negative stock has to be carefully perforated,
making the holes necessary to conduct the film by aid of sprockets
through the camera and the projectoscope. To still further understand
this explanation, see illustrations of the negative stock. Having
prepared the film in the dark room, we can load the camera in the dark
room and proceed to take the picture.

In taking an industrial or travelogue picture, after the camera is
in readiness, is not so much of an undertaking as taking a picture
of a drama or comedy, wherein a plot and players are concerned. The
travelogue or industrial pictures are simply photography, with the
additional manipulation of panoraming or turning the camera, which
requires an expert knowledge, acquired from experience and years of
study. There is a distinction and a big difference between the ordinary
photographer and the moving picture photographer, who is generally
known as a “camera-man.” A photographer, therefore, though of vast
experience, cannot step into a “camera-man’s” place and expect to “make
good.” The latter has to depend entirely upon his special experience
and judgment as to light and distance, focusing and general physical
conditions of the moving-picture camera, which is affected by static
and other electrical peculiarities of the atmosphere, to be avoided
by him. These, and many other points, are convincing evidence that
the moving-picture camera is entirely different from an ordinary
photographic camera. A moving-picture camera and tripod weigh from
fifty to one hundred pounds. There are two styles of cameras, one
which takes a single film and one which takes two films at once,
and each lens of the double camera must be equally well focused and
every feature to be depicted must be brought within the focus, which
generally occupies a radius of 8 feet in width by 10 feet in height.

[Illustration: SCENES FROM “OFFICER KATE.”]

[Illustration: RAW NEGATIVE STOCK. PERFORATED NEGATIVE STOCK.

Exact size of a Motion Picture Film]

When it comes to taking a photo-play, a drama or comedy, different
conditions of a varied nature have to be contended with. To proceed
intelligently in taking a photo-play, a scenario or manuscript is
essential. It must be prefaced with a well-written synopsis of the
story involved, cast of characters, scenes to be enacted and a list of
properties required in the scenes. The director, or producer, of the
play, being furnished with such a guide, proceeds to select the actors
and actresses (called players) suitable for the parts and the filling
of the cast. This being accomplished, he insists that each one of the
players read the scenario in order to be familiar with his or her
part and understand the whole play before going into the picture. The
director instructs them as to the costumes fitting the parts and then
confers with the costumer concerning the furnishing of proper dress
for each one of the players. The director is ready to go on with the
performance of the play, and tells his cast to appear for rehearsal
at a set hour. At that time he puts them through a thorough course of
training or rehearsal, to “get over” and register the meaning of each
thought which is to be expressed by their actions. Sometimes a scene is
rehearsed four to six hours before it is photographed. A one-reel play
is generally 1000 feet in length, and it is very important that the
director, if he has twenty scenes, for instance, to introduce within
that 1000 feet, to time the scenes to the length of his film; that is,
if he has twenty scenes within one thousand feet, each of the twenty
scenes must not average more than one minute each. If one should happen
to be more than one minute, then he has to condense another scene less
than one minute, in order to bring all within the twenty minutes or
1000 feet.

[Illustration: STAGING A MOTION PICTURE IN A STUDIO

REHEARSING SCENE IN STUDIO]


The Size of Each Picture on the Film.

So you can see from this that it needs very careful rehearsal and nice
calculation to bring a well-acted and convincing play within so short
a time, to tell the whole story intelligently. Having done all this,
the director is ready to have the “camera-man” do his part of the
work. He draws his lines within the range of the camera, which do not
exceed eight or ten feet in the foreground. This is another point to be
considered on the part of the director, because all the action has to
be carried out within the eight feet of space, which is really confined
to that much stage width. Here again is where the camera-man has to
watch very carefully, not only the workings of his camera, but the
players; always alert that they are in the picture, and assisting the
director by his observations. The size of each picture as taken on the
film is ³⁄₄ by 1 inch. It is magnified ten thousand times its actual
size when we see it on the screen in a place of exhibition. A full reel
of 1000 feet shows 16,000 photographs on the screen during the twenty
minutes it consumes in its showing. The future of moving pictures is
no longer a matter of speculation. The business is an established
one, and its further developments are only matters of time. The
possibilities and uses of the animated art are unlimited. Already it
is felt in educational, religious, scientific, and industrial affairs.
Their influence in matters of sanitation and all civic improvements,
construction and mechanics, is invaluable. As a medium of wholesome
entertainment and solid instruction it is unsurpassed.

These are merely suggestions of a few phases of its utility and it is
only a natural conclusion that it will be so far-reaching in its uplift
that it will surpass the expectations of the most sanguine.

[Illustration: THE DEVELOPING ROOM.]

To develop, tint and clear the films, large tanks of wood or soapstone
are used. The films, which are wound upon the wooden frames, or racks,
are dipped into these vats, filled with the necessary chemicals and
liquids. The films being wound on frames enables the developers to
examine them without handling them. The tinting is done by similar
methods to give the necessary tint, coloring in red, sepia, blue, green
or yellow, imparting to them the effect of night, sunlight or evening,
whichever the case may be. The films are finally cleared, to wash them
clear of any extraneous chemicals or matter which might streak or
scratch the films, and avoid any objectionable matter that might mar
their appearance when shown on the screen or in the process of handling.

~EACH PICTURE IS FIRST EXHIBITED AT THE STUDIO~

As soon as convenient after a film is finished it is taken to the
exhibition rooms, at the studio, where it is thrown onto the screen. It
is reviewed first by the heads of the departments and the directors,
and later by players and all those interested in it. The projectoscopes
or moving-picture machines are run by motor, presided over by licensed
operators, who are kept on the job continually.

These exhibition rooms are called, in the parlance of the studios,
“knocklodeums,” for here is where everything is criticised. Players’
acting and fitness are judged by their appearance and conduct on the
screen and decision given as to their qualifications. The quality of
the photography, developing and the picture as a finished production is
here determined by the heads of the concern.

[Illustration: DRYING ROOM.]

~THE BOARD OF CENSORS PASSES ON EVERY PICTURE~

Every picture before it is released for exhibition must be passed upon
by the Board of Censors. It is run upon the screen and thoroughly
inspected, criticised, and every point involved thoroughly weighed
as to its effect upon the mind of the general public. If, in their
estimation, it is found objectionable in any particular, the
objectionable parts are eliminated, and if considered entirely harmful,
in its sentiments or influence, the picture is condemned. The majority
rules in the board’s judgment, although it is by no means infallible in
its decision. This board is composed of about sixty persons, who are
appointed by the government for their general qualifications, their
interest in the general welfare of the public, keenness as to morals
and uplift of the people at large. They do not receive salaries; their
services are _pro bono publico_.

[Illustration: TAKING A MILITARY SCENE OUTDOORS.]




THE STORY IN “PIGS IS PIGS”


[Illustration: “PIGS IS PIGS.”]

[Illustration:

  VITAGRAPH FAMOUS AUTHORS’ SERIES BY ELLIS PARKER BUTLER.

  _You Have Seen Pigs, but Never Such Pigs as These. Two of Them Become
  Eight Hundred Pigs so Rapidly, They Set Bunny Daffy and Almost Ruin
  the Express Business._

  _Director_--GEORGE D. BAKER. _Author_--ELLIS PARKER BUTLER.

  CAST.

  _Flannery, an Express Agent_                  JOHN BUNNY
  _Mr. Morehouse_                         ETIENNE GIRARDOT
  _Clerk in Complaint Dept._          COURTLAND VAN DEUSEN
  _Head of Claims Dept._                      WILLIAM SHEA
  _Mr. Morgan, Head of Tariff Dept._       ALBERT ROCCARDI
  _President of Company_                    ANDERS RANDOLF
  _Prof. Gordon_                            GEORGE STEVENS

After a strenuous argument with Flannery, the local Express Agent,
Mr. Morehouse refuses to pay the 30c charges on each of two guinea
pigs shipped him, claiming they are pets and subject to the 25c rate.
Flannery replies, “Pigs is pigs and I’m blame sure them animals is
pigs, not pets, and the rule says, ‘30c each.’” Mr. Morehouse writes
many times to the Express Company, claiming guinea-pigs are not common
pigs, and each time is referred to a different department. Flannery
receives a note from the Tariff Department inquiring as to condition
of consignment, to which he replies, “There are eight now! All good
eaters. Paid out two dollars for cabbage so far.” The matter finally
reaches the President, who writes a friend, a Zoological Professor.
Unfortunately that gentleman is in South Africa, causing a delay of
many months, during which time the pigs increase to 160. At last word
is received from the learned man proving that guinea-pigs are not
common pigs. Flannery is then ordered to collect 25c each for two
guinea-pigs and deliver the entire lot to consignee. There are now 800
and Flannery is horrified to find Morehouse has moved to parts unknown.
He is about to give up in despair when the company orders him to
forward the entire collection to the Main Office, to be disposed of as
unclaimed property, in accordance with the general rule.]

[Illustration: BUNNY FEEDING THE PIGS.]

[Illustration]


Who Made the First Moving Pictures?

~THE FIRST MOVING PICTURE CAMERA~

The first device which produced the motion-picture effect was nothing
but a scientific toy. The idea is almost as old as pictures themselves.
This toy we speak of was called a zoetrope. It consisted of a whirling
cylinder having many slits in the outside through which you could see
by looking into the cylinder a picture opposite each slit. The pictures
were drawn by hand and the artist aimed to place the pictures within
the cylinder in such order that each succeeding one would represent the
next successive motion of any moving object in making a movement as
near as he could draw it; when the cylinder was whirled with the slits
on a level with the eye, the effect produced was of a continuous moving
picture.

A great many devices were produced as a result of this toy for
presenting the effect of pictures so arranged, but until photography
was invented no way was found for making the pictures to be viewed
except such as were drawn by artists. But when photography was
developed it was possible to get actual successive photographs.
The greatest difficulty was found in taking photographs in such
quick succession that all of the motions in the moving object were
taken without any skipping. This difficulty was for the first time
successfully overcome by Muybridge in 1877. He arranged a row of
twenty-four cameras with string trigger shutters, the string of each
shutter being stretched across a race track. A moving horse approaching
down the track broke the strings as he came to them, thus operating
each of the cameras in turn in quick succession and securing a series
of pictures of the moving horse within a very short time. There were
twenty-four pictures to this film when reproduced in the devices then
known for projecting pictures, and this method required one camera for
each section of the picture produced. Of course, the length of the
series was thus limited greatly.

About ten years later Le Prince arranged what he called a multiple
camera. This was as a matter of fact a battery of sixteen automatically
reloading cameras in which strips of film were used. Each of the
sixteen cameras took a picture in turn and then automatically brought
another strip of the film into position, so that camera number one took
the seventeenth picture, the twenty-third, the forty-ninth, etc., and
each of the other cameras took their various pictures in turn. With
this camera a film of any required length could be produced.

The Le Prince camera was therefore the real parent from which
the modern motion-picture camera sprang. The first really modern
motion-picture camera was built in a single case with a battery of
sixteen separate lenses and sixteen shutters. These were operated by
turning a crank. The pictures were taken on four strips of film. When
the crank was turned the exposure was made to each of the sixteen
lenses in succession, and when the series was completed the films
were cut apart and pasted together in a single strip of film, the
pictures themselves being arranged in the proper order. The principal
development of this camera, as found in the present method of making
motion pictures, is the invention of the flexible film negatives; the
transparent support for the print which permits the pictures to be
projected in enlarged form upon a screen; and the system of holes in
the margin of the film by which the film is held in perfect alignment
for projecting the pictures.

But a few years ago, then, the motion picture was a child’s toy. To-day
it forms the basis for not only a very large and profitable business
for many people, but a source of amusement and education to millions
of people at reasonable prices. To-day the motion-picture business is
regarded as one of the world’s greatest industries.

No corner of the world is so far remote but the motion-picture man
finds his way there, either as an exhibitor or as a producer. Nothing
happens in the world to-day but the motion-picture man with his
camera is on the job if it is a happening that can be preserved in
motion pictures and worthy of that. The dethronement of kings and the
inaugurations of presidents are all alike to him. If there is a war, he
is found in all parts of the field, and is the first to see the parade
when there is a peace jubilee. Disasters, horrors, heroes and criminals
pass before his lens and he gives us a moving panorama of everything
that is interesting, in nature, in real life, and in fiction.


Taking Motion Pictures a Simple Operation.

Motion-picture photography is mechanically simple and the projection of
the pictures on the screen was made possible by the improvement in dry
plates which made instantaneous photography successful, together with
the invention of the process of using celluloid films for negatives.
Motion pictures consist of a series of photographs made rapidly and
then projected rapidly on the screen. In this way one picture follows
another so quickly that the change from one picture to another is
not noticed and the movements and actions of the persons or things
photographed are reproduced in a life-like manner.


Is the Hand Quicker Than the Eye?

There is no question that the hand can be moved so quickly that the
eye cannot detect the movement. This is proved by the motion picture
when projected on the screen. In moving pictures the quickness of
the machine deceives the eye and the transition from one picture to
another is done so rapidly that the change is not seen and the apparent
movement is continuous and unbroken.

The film made by the motion picture is a “negative” in which the colors
are reversed, the blacks being white and the whites black, exactly as
in still photography. The film used in the projection machine is a
“positive,” in which the lights and shadows have their proper values.
The principle and process is exactly the same as in making lantern
slides and window transparencies.


Does the Film Move Continuously?

In making the negative for the motion picture the film does not move
forward regularly, but it goes by jumps. It is absolutely still at the
moment of exposure. The same is true in projecting the picture on the
screen. In most projection machines the film is stationary three times
as long as it is in motion, though in some machines the proportion is
one in six. In the taking of the picture, the film is really stationary
one-half of the time. As pictures are usually projected at the rate
of fourteen or sixteen to the second, this means that each separate
picture appears on the screen three-fourths of one-sixteenth of a
second, or three-sixty-fourths of a second, and


How Are Freak Pictures Made?

Freak pictures are usually the result of clever manipulation of the
camera or the film. Articles or individuals can be made to instantly
disappear by stopping the camera while the article is removed or the
person walks off the stage, the other characters holding their pose
until the camera is again put in motion. In some films in which a
person is thrown from a height or is apparently crushed under a steam
roller the effect is gained by the live person walking away after the
camera is stopped and a dummy substituted to undergo the death penalty.

By projecting the picture at a faster rate than it was taken,
excruciatingly comic scenes are sometimes devised. An automobile going
ten miles an hour, by speeding up the projection machine, may be made
to apparently move at a hundred miles an hour, and by increasing in
the same way the apparent speed of persons dodging the demoniac auto
exceedingly ludicrous effects are had.

By mechanical means in combining two or more negatives into one
positive a man can be shown fencing with himself or even cutting his
own head off.

  Pictures by courtesy of the Vitagraph Company.

[Illustration: HOW RUBBER TIRES ARE MADE

WASH ROOM.[4]]

  [4] These and the following Pictures by courtesy of the Goodyear Tire
  and Rubber Co.




The Story in a Ball of Rubber


How Crude Rubber Is Treated.

_Washing._--When the crude rubber arrives at the factory of the rubber
manufacturer, it is generally stored in bins in dark and fairly cool
store-rooms, where it is kept until ready to be used. The rubber passes
directly from the storage bins to the wash-room, where it is cut up
into small pieces, put into large vats of warmed water and allowed
to soak, in order to soften it sufficiently to be broken down in the
machines. It is then fed into a cracker, a machine consisting of two
rolls with projections on their surfaces shaped like little pyramids,
the two rolls revolving with a differential, one going considerably
faster than the other, and being adjustable, so that they can work
close together or with some distance between them. The rubber is fed
between these rolls and broken down into a coarse, spongy mass. Water
flows on to the rubber during the process, bringing down sand, dirt,
bark, and the many other foreign materials which come mixed with the
rubber. The rubber is put through this machine a number of times, until
it is worked into a uniform condition. Some of the rubbers, like the
Ceylons and Paras, will sheet out into a coarse sheet by being put
through this machine; others, like the majority of the African rubbers,
will fall apart and come down in chunks and have to be fed into the
machine with a shovel.

[Illustration: PREPARING CRUDE RUBBER FOR MAKING TIRES

CALENDER ROOM.]

After the rubber is broken down sufficiently in the cracker, it is
next put through a washing machine, which is built very similar to
the cracking machine, except that the rolls are grooved or rifled, so
that their action is not so severe on the rubber. A large quantity of
water is kept constantly running over this machine while the rubber
is being put through, and the rolls work very close together, so that
the rubber is finely ground and run out into a thin and comparatively
smooth sheet, allowing the water flowing between the rolls to take out
practically all of the foreign matter that remains. The rubber is run
through this machine a number of times until the experienced inspectors
in charge are satisfied that it is thoroughly washed. Some types of
rubber, such as Manicoba, which have large quantities of sand in them,
are washed in a special form of washing machine known as the beater
washer. This is an endless, oval-shaped trough with a fast-revolving
paddle-wheel. In this machine the rubber is submerged in water, after
being broken down in the cracker, and the sand is literally knocked out
of it by the paddle-wheel. The sand drops to the bottom of the machine,
where if is drained off, while the rubber floats to the top and is
there gathered and then put through a regular washing machine for the
final sheeting out.

_Drying._--From the wash-room the rubber goes to the dry-room. Before
the rubber can be used in any articles of commercial value, it must
be thoroughly dried, as any moisture in the stock would turn to steam
during the vulcanizing process and cause blisters or blow-holes to form
in the goods. There are two ways in which rubber is usually dried.
The method mostly used, and which is generally practiced with all the
better grades of gums, is to hang the washed strips on horizontal
poles and space them in aisles, so that air can freely circulate all
around the surface of the rubber, the dry-room being kept at a constant
temperature. To properly dry the rubbers by this method takes from four
to six weeks. The other method of drying is by means of a vacuum-drier.
Low-grade rubbers which have a comparatively large percentage of
resin in their composition cannot bear their own weight when hung on
horizontal poles, but drop off and stick in piles on the floor. Hence,
these rubbers have to be dried in a peculiar manner. They are laid in
trays which are placed into a large air-tight receptacle. The air is
then withdrawn from this receptacle and the interior heated by means of
steam coils. This allows the water to be evaporated off from the rubber
at a considerably lower temperature than that at which water boils
under atmospheric pressure, and at such a low temperature, and in such
a short time, that the rubber is not affected. By this process these
rubbers can be dried in a few hours.

_Mixing._--After the rubber has been thoroughly dried, it is ready to
be mixed in proper proportions with the various ingredients which are
used in rubber compounding, to give the desired quality of rubbers for
the various products for which they are intended. In order that rubber
shall vulcanize, it is necessary to mix with it a certain proportion
of sulphur, vulcanizing, or curing, as it is sometimes called, being
merely the changing of a physical mixture of rubber and sulphur into
a chemical compound of these ingredients, by the application of heat.
Besides sulphur, some of the more important ingredients used in
compounding rubber are:

_Zinc oxide._--This toughens the rubber and increases its wearing
properties and tensile strength.

_Barium sulphate._--This stiffens the rubber and adds weight, so
reducing the cost.

_Lithopones._--This whitens the stock and makes it soft, and is used
extensively in druggists’ sundries.

_Antimony sulphide._--This makes the stock red and is a preservative
against oxidation.

_Litharge._--This has the same action as antimony sulphide, but makes
the stock black.

_White lead._--This hastens the cure and is extensively used in gray
and black stocks, and is a good filler or weight adder.

_Magnesia oxide and carbonate._--These are used as fillers for white
stocks.

_Oxide of iron._--Used for coloring red and yellow stocks.

_Lime_ (unslacked).--This hastens vulcanization and chemically removes
any water left in the rubber.

_Whiting._--This is used only as a cheap filler to increase quantity
and lower cost.

_Aluminum silicate._--This is used chiefly as a filler.

There are also used in compounding what are known as the various
substitutes. These are chiefly linseed oil products and mineral
hydrocarbons which are more or less elastic, and act somewhat as a flux.


Why Don’t We Use Pure Rubber?

There seems to be a general impression that the various ingredients
which are mixed with rubber are put into the compounds merely to
cheapen the product and to lower the grade of the material. This
is true in many cases, such as the general line of molded goods,
rubber heels, bicycle grips, automobile bumpers, etc., but in many
cases, such as tires, packing, belting, etc., these ingredients are
added to toughen the gum, increase its wearing qualities, to make it
indestructible when subjected to heat, or to make it soft and yielding
so that it can be forced into fabric, etc.

~PROCESS NECESSARY TO MAKING RUBBER GOODS~

In the general process of manufacture the sheeted rubber is sent
directly from the dry-room to the compound-room, where the various
ingredients are weighed out into proper proportions along with the
rubber to make up a batch, and placed in receptacles ready to be mixed.
The batch is then sent into the mill-room to be mixed into a uniform
pasty mass, which is the characteristic uncured, or so-called green,
rubber compound. The mixing is done in the mill. This is a very heavy
machine, constructed similarly to a cracker and a washer except that
it is much larger and heavier, and the rolls are perfectly smooth and
run closer together. No water at all is used on the batch during the
mixing. There are steam and cold water connections to the mills which
are connected with hollow spaces inside the rolls, so that the latter
can be kept at any temperature desired. The general process of mixing
is as follows:

First the rubber portion of the batch is thrown into the mill and
is worked and warmed up until it takes on a very sticky and plastic
consistency. When it has arrived at a certain stage of plasticity,
the various compounds in the batch, which are always in the form of
very fine powders, are thrown in the mill, being worked by the rolls
into the rubber. The compounds are generally thrown on, a small amount
at a time, until they are all taken up by the rubber. The batch is
then allowed to go through and through the mill, over and over again,
until the mixture is absolutely uniform throughout the whole mass. The
consistency of the rubber, during this operation, is such that the
batch can be made endless around one of the rolls of the mill, so that
it is constantly feeding itself between the rolls.

After the batch is properly mixed, it is cut off the rolls in sheets
and rolled up and sent to the green-stock store-room. In this
store-room the compounded, uncured gums are kept in different bins,
according to the nature of the compound, and are there allowed to
season a certain length of time, after which they are delivered to the
various departments of the factory in which they are going to be used.

Another form in which rubber is used is the so-called Rubber-Cement.
Rubber or any of its compounds are readily soluble in naphtha. In this
process, the compounds, after being milled, are chewed up and washed
in specially constructed cement-mills and there mixed with a certain
proportion of naphtha which gives a thick solution.

_Spreading and calendering._--Rubber which is used for the general
line of molded goods, solid tires, some kinds of tubing, etc., goes
directly to the various departments from the green-stock store-room,
while rubber used for boots and shoes, waterproof fabrics, many of
the druggists’ sundries, belting, pneumatic tires, inner tubes, etc.,
has to be sheeted out, and some of it forced into fabric before it
goes to the various departments. This sheeting-out of the gum, as well
as applying the rubber to fabrics, is done generally by two methods;
either by spreading a solution of the rubber and naphtha onto the
fabric, or by calendering the rubber between heavy rolls in a rubber
calender.

In the spreading process, a machine called a spreader is used. The
fabric to which the rubber is to be applied is mounted in a roll at
one end of the spreader and from the roll passes through a trough of
rubber-cement, and then up over a so-called doctor roll, and under a
knife edge, which allows only enough cement to pass through to fill the
pores of the fabric. From this knife the cemented fabric passes over
a steam drying chest and is then rolled up with a roll of liner cloth
to prevent its sticking together. Fabric treated in this manner must
be put through the spreader a number of times before it has sufficient
rubber on it to be used in the products for which it is intended.

For calendering rubber, a machine called a rubber calender is used.
This machine is made with three and sometimes four heavy rolls, which
are capable of very fine adjustment. The rubber from the green-stock
store-room is first warmed up on a small mixing mill and is then fed
between the rolls of the calender, coming through in a thin sheet of
required thickness, and is wound up in a liner cloth and sent directly
to the departments, where it is used for inner tubes, druggists’
sundries, etc., where only rubber and no fabric is used. Where the
rubber is to be applied to fabric, the fabric is put through the
calender rolls with the rubber, and the rubber is literally ground into
the fabric. Fabric treated in this manner is known to the trade as
friction, and is generally used in the manufacture of pneumatic tires,
belting, hose, etc. For boots, shoes, and other special work, calenders
are used which are equipped with rolls engraved with the shapes of the
soles and other parts of the articles in question, so that the sheet
of rubber coming from the machine has imprinted on it the shapes and
thickness of the articles for which it is intended.

After passing through such of the above processes as are required
the rubber is ready to be made up into the various articles known to
the rubber trade, such as boots and shoes, mackintoshes, waterproof
fabrics, for balloons, aeroplanes, tentings, etc., mechanical goods,
such as rubber heels, horseshoe pads, packing, tiling, automobile and
other bumpers, artificial fish bait, etc., druggists’ sundries, such as
nursing-bottles, nipples, syringes, bulbs, hot-water bottles, tubing,
etc. tobacco pouches, rubber belting, golf and other balls, insulated
wire, fire and garden hose, inner tubes, tires, and the many other
commodities into the manufacture of which rubber enters.

[Illustration: TRADING ROOM]


How Are Automobile Tires Made?

From the calender room of the rubber factory the stock is received
in the automobile tire department, in the form of large rolls of
rubber-coated fabric, and in rolls of sheeted rubber of various
thicknesses and widths. The rubber-coated fabric is first cut into
strips of proper widths so that the edges will extend from bead to
bead over the crown of the tire. These strips are always cut on the
bias, generally at a 45-degree angle, with the edge of the roll, and
were formerly all cut on a cutting-table, a table about 50 feet long
and 6 feet wide, covered with sheet metal. The cutting was done by two
men, each having a knife and each cutting half-way across the cloth
along the edge of a straight-edge so arranged as to be always set at 45
degrees with the edge of the table. This method of cutting is gradually
being put aside by the use of the bias cutter, an extremely up-to-date
machine having jaws which ride up to the end of the fabric and pull
it for a certain distance under a knife set at a 45-degree angle, the
knife being set to cut just when the jaws have arrived at the limit of
their motion. The action is repeated so that the machine cuts about
eighty strips a minute. These strips are fed onto a series of belts
which carry them to where they are placed, by boys, into a book having
a leaf of common cloth between each strip of gum fabric, to prevent the
strips from sticking together.

[Illustration: CURING ROOM--SOLID TIRES.]

[Illustration: MAKING A PNEUMATIC TIRE

CURING ROOM, FIRST CURE--PNEUMATICS.]

[Illustration: SPREADER ROOM.]

The majority of automobile tires to-day are machine built, but there
are still a great many built by hand and this is the process we shall
describe first. In this process the books of fabric are laid up and
spliced into proper lengths to go around the tire and allow a proper
lapping for the splices. The proper number of these laid-up pieces,
or plies, as they are called, are placed together with cotton cloth
between and taken to the tire builder. The tire builder mounts the
core, upon which the tire is to be built, on the building stand,
generally cementing it so that the first ply of fabric will stick in
place. The first ply is then stretched onto the core and spliced,
rolled down with a hand roller onto the sides of the core, and trimmed
with a knife at the base. The following plies are put on and rolled
down in the same manner, the beads being put in at the proper time,
according to the size and the number of plies to be used. After all the
plies have been put onto the core the so-called cover rubber is put on.
This cover rubber is generally a sheet of rubber about one-sixteenth of
an inch thick or more, and of the same compound as the rubber on the
fabric.

[Illustration: HOW THE TREAD OF A TIRE IS MADE

TREAD LAYING ROOM.]

In the case of the machine-built tire, the result is the same, but the
stock is handled as follows: After the rubber-coated fabric has been
cut on the bias cutter, the strips are spliced and rolled up in rolls
on a spindle which is placed in the so-called tire-building machine.
The tire core is mounted on a stand attached to the machine, so that it
can be revolved by power, and the fabric is drawn onto the core from
the spindle under a certain definite tension. The tire-machines roll
the fabric down by power, and the beads are put into place before the
tire and core are removed from the machine. Thereafter the process is
the same as in the case of the hand-built tires.

After the cover rubber is in place the tire is ready to have the tread
applied. The tread is made up independently of the tire by laying up
narrow strips of rubber, in different widths, in such a way that the
center of the tread is thicker than the edges. In the case of the
so-called single-cure tires, which are wholly vulcanized at one time,
this tread is applied to the tire directly after the cover, a strip of
fabric called the breaker-strip generally being placed underneath, and
the building of the tire so completed.

In the general method of curing, the tire is allowed to remain on
the core, and is either bolted up in a mold and put into an ordinary
heater, or it is laid in a mold and put into a heater press, where the
hydraulic pressure keeps the two halves of the mold forced together
during the vulcanizing process. After the vulcanizing is completed, the
tire is removed from the mold, the inside is painted with a French
talc mixture, the tire inspected and cleaned, and so made ready for the
market. In some methods of curing, instead of the tire being put in a
mold, it is put into a so-called toe-mold, which is virtually a pair of
side flanges only reaching up as high as the edges of the tread on the
side of the tire. After the flanges are fastened into place, the whole
is cross-wrapped, the cross-wrapping coming in direct contact with
the tread. The tire in this condition is then put into the heater and
vulcanized, giving the so-called wrapped tread tire. Still another form
of curing is to inflate a kind of canvas inner tube inside the tire and
place the whole in a mold. This is known as the air-bag mold process.

[Illustration: PNEUMATIC-TIRE ROOM--SHOWING TIRE-BUILDING MACHINES.]


How Are Inner Tubes Made?

Inner tubes for pneumatic tires may be classed under three headings,
according to the methods used in their manufacture, viz., seamed tubes,
rolled tubes, and tube-machine tubes. By far the greater number of
tubes come under the first two headings. For seamed tubes, the rubber
is taken from the calender in the form of sheets from one-sixteenth to
three-sixteenths of an inch in thickness. These sheets are cut into
strips of proper length and just wide enough to make a tube of proper
cross-section diameter when the two long edges are folded over and
fastened together with rubber cement. These two long edges are cut on a
bevel so that they make a good lap seam. The tube is then pulled over a
mandrel of proper size and a thin piece of wet cloth rolled around it,
and then it is spirally cross-wrapped with a long, narrow piece of wet
duck for its entire length. The whole is then put into a regular heater
and the tube vulcanized. After vulcanizing the wrapping is removed and
the tube stripped from the mandrel, turning the tube inside out, so
that the smooth side which is vulcanized next to the mandrel appears
outside, and the rough side showing the marks of the cross-wrapping is
inside. The valve hole is then punched in the tube, the valve inserted
and the open ends of the tube buffed down to a feather edge. The tube
in this state passes to the splicers, who cement the buffed ends and
splice them together, placing one open end within the other, making a
lapped seam around the tube about 2¹⁄₂ inches long. The cement used
in splicing is generally cured by an acid which chemically vulcanizes
the rubber without the application of heat. The tube is thus finished
and ready for the market. Rolled tubes are made from very thin sheet
rubber by rolling same over a mandrel of proper size, until the
required number of layers of thin rubber have been rolled on to give
the tube the desired thickness. The tube is then wrapped, cured and
spliced, in exactly the same manner as a seamed tube.


What Is Rubber?

Crude rubber is a vegetable product gathered from certain species of
trees, shrubs, vines and roots. Its characteristic peculiarities were
early recognized by the natives of the tropical countries in which it
is found. Records of the earliest travelers in these countries show
that the natives had used various articles, such as receptacles, ties,
clubs, etc., made from rubber, but it was not until about 1735 that
rubber was first introduced into Europe. In civilization rubber was
first used for pencil erasers and in waterproof cloth, and finally in
cements. Vulcanizing, or the curing of rubber, was not discovered until
1844, and thereafter the development of the rubber industry was very
rapid, especially in Great Britain.

[Illustration: WRAPPING ROOM--PNEUMATICS.]

There are many kinds and grades of rubber, and to-day these can be
divided into two chief classes, wild and cultivated.

[Illustration: PNEUMATIC-TIRE ROOM, SHOWING TIRE FINISHING.]

[Illustration: HOW THE CRUDE RUBBER IS SECURED

Gathering Rubber in South America.]

[Illustration: 1. Tapping Axe. 2. Tin Cup to Catch the Rubber Milk. 3.
The Beginning of a Rubber “Biscuit.” 4. A Palm Nut.]

[Illustration: Making Balls of Crude Rubber.]

[Illustration: Tapping the Trees in Japan.]

[Illustration: How the Rubber Looks when it comes to Market.]

[Illustration: Carrying Balls of Crude Rubber to Native Market.]

Pictures herewith by courtesy of The B. F. Goodrich Company, Ltd.


What Is Wild Rubber?

~WHERE RUBBER COMES FROM~

The first class, or wild rubbers, are collected from trees which have
grown wild and where no cultivation processes whatsoever have been
used. These rubber-producing trees, shrubs, etc., are found mostly in
Northern South America, Central America, Mexico, Central Africa and
Borneo.

The finest rubber in the world is Fine Para, and is gathered in the
Amazon regions of South America. This rubber has been gathered in
practically the same way for over a century. The natives go out into
the forests and, selecting a rubber tree, cut “V”-shaped grooves in the
bark with a special knife made for the purpose, these grooves being
cut in herring-bone fashion diagonally around the tree, with one main
groove cut vertically down the center like the main vein in a leaf.
The latex, or milk-like liquid, of the tree, from which the rubber is
taken, flows from these veins and down the center vein into a little
cup which the natives place to receive it. After the little cups are
filled they are gathered and brought into the rubber camp, and there
the latex is coagulated by means of smoke. This is done by the use of
a paddle which is alternately dipped into a bowl of the latex and then
revolved in the smoke from a wood or palm-nut fire. This smoke seems to
have a preservative effect on the rubber as well as drying it out and
causing it to harden on the paddle, each successive layer of the latex
causing the size of the rubber ball or biscuit to increase. When a
biscuit of sufficient size has been thus coagulated it is removed from
the paddle and is ready for shipment to countries where rubber products
are manufactured.

Para rubber is sold in three grades. Fine Para, which is the more
carefully coagulated or smoked rubber; Medium Para, which is rubber
gathered and smoked in the same way as Fine, but which has had
insufficient smoking, and, therefore, more subject to deterioration due
to oxidation, etc.; and Coarse Para, which is rubber gathered from the
drippings from the rubber trees after the cups have been removed. This
latter grade has generally a large percentage of bark and other foreign
substances mixed with it, and is subject to even more deterioration
than is Medium Para, as it is oftentimes not smoked at all.

Another important grade of rubber coming from South America is Caucho.
This tree grows similar to the Para trees and the rubber is gathered
in a similar manner, but is cured by adding to the latex some alkaline
solution and allowing the whole to dry out in the sun. The value of
this rubber can be greatly improved by better methods of coagulation.

From Central America and Mexico comes the Castilloa rubber. This
rubber is gathered from trees in a very similar manner to Para, and is
coagulated by being mixed with juices which are obtained by grinding
up a certain plant which grows in the Castilloa districts. After being
mixed with this plant juice, the Castilloa is spread out in sheets on
bull hides, where it is allowed to dry in the sun, after which the
rubber is rolled up and is ready for shipment. Castilloa is gathered
mostly from wild trees, but in Mexico it has recently been cultivated
to some extent.

From Mexico we also get Guayule. This rubber is obtained from a certain
species of shrub, the shrub being cut down and fed into a grinding or
pebble mill where the branches are crushed and ground and mixed with
water, and the rubber, which is contained in little particles all
through the wood, is worked out, being taken from the pebble mills in
chunks as large as a man’s fist.

From Central Africa and from Borneo come the so-called African gums,
such as Congo, Soudan, Massai, Lapori, Manicoba, Pontianic, etc. Some
of these rubbers are gathered from trees, but most of them from vines
and roots, and the methods of coagulation are varied. Practically all
of them are dried out in the sun. These rubbers are all of lower grade
than the Para rubbers of South America.

[Illustration: BAGS OF CACAO BEANS.]




The Story in a Stick of Chocolate


Where Does Chocolate Come From?

Perhaps no other one thing is so well known to boys and girls the world
over as chocolate. Yet there was a time, and not so many years ago, as
we figure time in history, when there were no cakes of chocolate, or
chocolate candies to be had in the candy shops, no chocolate flavored
soda water or chocolate cake. To-day quite a panic would be started if
the world’s supply of chocolate were cut off.

Chocolate is obtained from cacao, which is the seed of the cacao tree.
It is quite often called cocoa, although this is not quite a correct
way of spelling the word. The cacao tree grows to a height of sixteen
or eighteen feet when cultivated, but to a greater height when found
growing wild. The cacao pod grows out from the trunk of the tree as
shown in the picture, and is, when ripe, from seven to ten inches
long and from three to five inches in diameter, giving it the form
of an ellipse. When you cut one of these pods open, you find five
compartments or cells, in each of which is a row of from five to ten
seeds, which are imbedded in a soft pulp, which is pinkish in color.
Each pod then contains from twenty-five to fifty seeds, which are what
we call “cocoa beans.”

The cacao tree was discovered for us by Christopher Columbus, so that
we have good reason to remember him aside from his great discovery of
America. The discovery of either of these would be fame enough for any
one man, and it would be difficult for some boys and girls to say just
which of the two was Columbus’ greater discovery.

Columbus found the cacao tree flourishing both in a wild and in a
cultivated state upon one of his voyages to Mexico. The Indians of
Peru and Mexico were very fond of it in its native state. They did not
know the joy of eating a chocolate cream, but they had discovered the
qualities of the cacao bean as a food and had learned to cultivate it
long before Columbus came to Mexico.

Columbus took some of the cacao beans back with him to Spain and to
this day cacao is much more extensively used by the Spaniards than by
any other nation. The first record of its introduction into England is
found in an announcement in the _Public Advertiser_ of June 16, 1657,
to the effect that:

“In Bishopgate Street, in Queen’s Head Alley, at a Frenchman’s house,
is an excellent West Indian drink called chocolate, to be sold where
you may have it ready at any time and also unmade, at reasonable rates.”

Of course, by the time America became settled the people brought their
taste for chocolates with them.

[Illustration: VIEW OF COCOA BEANS IN BAG AND COCOA-GRINDING MILL.]


What is the Difference Between Cacao and Chocolate?

When the cacao seeds are roasted and separated from the husks which
surround them, they are called cocoa-nibs. Cocoa consists of these nibs
alone, whether they are ground or unground, dried and powdered, or of
the crude paste dried in flakes.

Chocolate is made from the cocoa-nibs. These nibs are ground into an
oily paste and mixed with sugar and vanilla, cinnamon, cloves, or other
flavoring substances. Chocolate is only a product made from cocoa-nibs,
but it is the most important product.

[Illustration: CACAO CRACKING MILL AND SHELL SEPARATOR.]

[Illustration: COCOA CRACKING AND SHELL SEPARATOR.

  WHERE THE SHELLS ARE SEPARATED FROM THE BEAN.]

[Illustration: COCOA MILL.]


What Are Cocoa Shells?

There are other products which are obtained from the cacao seed. One is
called Broma--which is the dry powder of the seeds, after the oil has
been taken out.

Cocoa shells are the husks which surround the cocoa bean. These are
ground up into a fine powder and sold for making a kind of cocoa for
drinking, although the flavor is to a great extent missing and it is,
of course, not nearly so nourishing as a drink of real cocoa.

[Illustration: COCOA ROASTER.

  MILL IN WHICH THE BEANS ARE ROASTED.]


What is Cocoa Butter?

The oil from the cacao seeds, when separated from the seeds, is what we
call cocoa butter. It has a pleasant odor and chocolate-like taste. It
is used in making soap, ointments, etc.

[Illustration: HOW CACAO BEANS GROW

COCOA TREE WITH FRUIT KNOWN AS COCOA PODS, WHICH CONTAIN THE COCOA
BEANS.]


How is Cacao Gathered?

When the cacao pods ripen on the tropical plantations, where the
climate is such that they can be grown successfully, the native laborer
cuts off the ripened pods as we see him doing in the picture showing
the pods on the tree. He does this with a scissors-like arrangement of
knives on a long pole.

As he cuts off the pods he lays them on the ground and leaves them to
dry for twenty-four hours. The next day they are cut open, the seeds
taken out and carried to the place where they are cured or sweated.

In the process of curing or sweating, the acid which is found with the
seeds is poured off. The beans are then placed in a sweating box. This
part of the process is for the purpose of making the beans ferment and
is the most important part of preparing the beans for market, as the
quality and the flavor of the beans and, therefore, their value in the
market, depends largely upon the ability of whoever does it in curing
or fermenting.

Sometimes the curing is done by placing the seeds in trenches or holes
in the ground and covering them with earth or clay. This is called
the clay-curing process. The time required in curing the cacao beans
varies, but on the average requires two days. When cured they are
dried by exposure to the sun and packed ready for shipping. At this
time beans of fine quality are found to have a warm reddish color. The
quality or grades of beans are determined by the color at this stage.

[Illustration: CHOCOLATE MILL.]


How Chocolate is Made.

When the cacao beans arrive at the chocolate factory they are put
through various processes to develop their aroma, palatability and
digestibility.

~PROCESSES IN CHOCOLATE MAKING~

The seeds are first roasted. In roasting the substance which develops
the aroma is formed. The roasting is accomplished in revolving
cylinders, much like the revolving peanut roasters, only much larger.
After roasting the seeds are transferred to crushing and winnowing
machines. The crushing machines break the husks or “shells,” and the
winnowing machine by the action of a fan separates the shells from the
actual kernel or bean. The beans are now called cocoa-nibs. These nibs
are now in turn winnowed, but in smaller quantities at a time, during
which process the imperfect pieces are removed with other foreign
substances. Cacao beans in this form constitute the purest and simplest
form of cacao in which it is sold. The objection to their use in this
form is that it is necessary to boil them for a much longer time, in
order to disintegrate them, than when they are ground up in the form of
meal. For that reason the nibs are generally ground before marketing as
cacao or cocoa.

Another form in which the pure seeds are prepared is the flaked
cocoa. This is accomplished by grinding up the nibs into a paste.
This grinding is done in a revolving cylinder machine in which a drum
revolves. In this process the heat developed by the friction in the
machine is sufficient to liquefy the oil in the beans and form the
paste. The oil then solidifies again in the paste when it becomes cool.

[Illustration: CHOCOLATE FINISHER.]

What we know as cakes of chocolate are made from the cocoa-nibs by
heating the mixture of the cacao, sugar and such flavoring extracts as
vanilla, until an even paste is secured. This paste is passed several
times between heavy rollers to get a thorough mixture and finally
poured into molds and allowed to cool. When cool it can be taken from
the molds in firm cakes and wrapped for the market. This is the way
Milk Chocolate is made. The difference in the taste and consistency of
milk chocolate depends upon how many different things the chocolate
maker adds to the pure cocoa-nibs to produce this mixture. Often
substances such as starchy materials are added to make the cakes more
firm. They add nothing to the quality of the chocolate.

[Illustration: CHOCOLATE MIXER.]

~HOW CHOCOLATE CANDIES ARE MADE~

Chocolate-covered bonbons, chocolate drops, and the many different
kinds of toothsome confections are prepared in the American candy
factories, as we all well know. The chocolate covering of this
confectionery is generally put on by dipping the inside of the choice
morsel in a pan of liquid chocolate paste and then placing the bits in
tins to allow them to cool and harden.

[Illustration: CHOCOLATE MIXING AND HEATING MACHINE.]

A great many of the choicest bits of confectionery are now produced by
machines entirely. These machines are almost human, apparently, as we
see them make a perfect chocolate bonbon which is delivered to a candy
box all wrapped for packing. These wonderful machines thus give us
candy which has not been touched by the hands of any one prior to the
time we thrust our own fingers in the brightly-decorated box and take
our pick of the assortment it offers.

[Illustration: WHERE THE INDIVIDUAL PIECES OF CONFECTION ARE WRAPPED.]

[Illustration: THE TALLEST BUILDING IN THE WORLD

WOOLWORTH BUILDING, NEW YORK CITY.

This building, the tallest in the world, is equipped with 26 gearless
traction elevators.

Two of the elevators run from the first to the fifty-first floor with
actual travels of 679 feet 9¹⁄₂ inches and 679 feet 10¹⁄₄ inches,
respectively. There is also a shuttle elevator which runs from the
fifty-first to the fifty-fourth floor.

Total height of building from curb to base of flagstaff, 792 feet.]

[Illustration: HOW AN ELEVATOR GOES UP AND DOWN

COMPLETE GEARLESS TRACTION ELEVATOR INSTALLATION.]




How Does an Elevator Go Up and Down?


Ordinarily, when we think of an elevator we think merely of the cage or
car in which we ride up or down. But the car is really only the part
which makes the elevator of service to man, and from the standpoint of
the machinery, is a relatively unimportant part of the equipment.

There are two principal types of elevators used to-day; the hydraulic,
which is worked by water under pressure, and the electric, which is
worked by electricity through an electric motor. The latter type,
because of the tendency towards the general use of electricity in
recent years, has largely superseded the hydraulic, and, as when you
think of elevators you probably have in mind those you have seen in
some huge skyscraper, we shall look at one of these.


What are the Principal Parts of an Elevator?

The most advanced type of elevator to-day is called a Gearless Traction
Elevator. In this elevator the principal parts are a motor, a grooved
wheel on the motor shaft called a driving sheave and a brake, all
mounted on one cast-iron bed-plate; a number of cables of equal length
which pass over the driving sheave and thence around another grooved
wheel called an idler sheave, located just below the driving sheave,
and to one end of which is attached the car or cage, and to the other
end a weight called a counterweight; also a controller which governs
the flow of electric current into the motor and thereby the speed,
starts and stops of the elevator car. Although the controller, motor,
brake and sheaves are usually placed way at the top of the building out
of our sight, they are really very important parts of the elevator.

The cage or car in which we ride is held in place by tracks built
upright in the elevator shaft, and the counterweight at one side of the
shaft travels up and down along two separate upright tracks. When the
car goes up the counterweight on the other end of the cables goes down
an equal distance. The counterweight is used to balance the load of the
car and to make it easier for the motor to move the car.

Electricity is the power that makes the car go up or down. The operator
in the car moves a master switch--in one direction if he wishes to go
up, in the other direction if he wishes to go down. This master switch
sets the electro-magnetic switches of the controller at the top of the
hatchway into action, electrically, and the controller in turn allows
the electric current to flow into the motor. The motor then begins
to revolve, gradually at first, and then faster, turning the driving
sheave with which it is directly connected. As this driving sheave
revolves, the cables passing over it are set in motion, and the car and
counterweight to which they are attached begin to move.


Why Does Not the Car Fall?

[Illustration: THE PRINCIPAL PARTS OF AN ELEVATOR]

Of course, the question of safety is a very important one in any
elevator, and you wonder what would happen if the cables broke. You
think of this especially when you are going up in one of the big
skyscrapers--where the elevators sometimes travel to a height of 700
feet. It can be truthfully said that on every modern elevator there
are safety devices which should make it practically impossible to have
a serious accident, due to the fall of the car. Every elevator is
equipped with wedging or clamping devices which automatically grip the
rails in case the car goes too fast either up or down. These gripping
devices can be adjusted to work at any speed that is desired above the
regular speed. It is not at all probable that all the cables will break
at once, because there are usually six of these, and any one of them is
strong enough to hold the car if the others break; but even if they all
should break the gripping devices on the rails will operate and hold
the car safely, just as soon as it starts down at great speed.

Suppose that the car should descend at full speed, but not sufficiently
fast to work the rail-gripping devices, it would be brought to a
gradual rest at the bottom of the hatchway, because of the oil-cushion
buffer against which it would strike. This is a remarkable invention,
with a plunger working in oil in such a way that a car striking it
at full speed will come to rest so gradually that there is scarcely
any shock. You have perhaps seen a clever juggler on the stage throw
an ordinary hen’s egg high into the air and catch it in a china dish
without cracking it He does it by putting the dish under the falling
egg just at the right moment, and bringing the dish down with the egg
at just the right speed, so that eventually he has the egg in the dish
without cracking it. The trick is in calculating the rate of speed of
the falling egg accurately and adjusting the insertion of the dish
under the falling egg to a nicety. The oil-cushion buffer in the modern
elevator works in very much the same way.

[Illustration: GENERAL ARRANGEMENT OF ROPING FOR GEARLESS TRACTION
ELEVATOR INSTALLATION.]

If it were not for the genius which has made possible these new types
of elevators we could not have the high buildings. The elevators in the
Woolworth Building are the latest type in modern elevator construction.
In this one building alone there are 29 elevators, and when you are
told that the electric elevators in the United States installed by
a single company represent a total of 525,000 horse-power, you will
have some idea of the power required to operate elevators all over the
country.




Does Air Weigh Anything?


Air is very light, so light that it seems to have no weight at all;
but, if you will think a minute you will see that it must have some
weight, because birds fly in it and balloons can be made to float
through it. It has been found that one hundred cubic inches of air
at the sea level weighs, under ordinary conditions, about thirty-one
grains. This seems a very small weight, but when we remember the
thickness of the atmospheric envelope over the earth we see that it
must press quite heavily upon the earth’s surface. There is a very
simple instrument called a barometer, which is used for measuring the
amount of this pressure. The name means pressure-measure.

Another striking feature of air is its elasticity, and this explains
something that is noticed by all mountain climbers. On a high mountain,
it is difficult to get enough air to the lungs, though one breathes
rapidly and deeply. The reason is, that the air at the foot of the
mountain is compressed by the weight of that above it, and consequently
the lungs can hold more of it than of the air on the mountain top,
which has less weight resting upon it and is, therefore, not so much
compressed. On account of the ease with which it is compressed, we find
that more than half of all the envelope of air that surrounds the earth
is within three miles of the surface.

When air is chemically analyzed it is found to consist of a number of
substances mingled together, but not chemically united. These include
nitrogen, oxygen, argon, carbonic acid gas, water vapor, ozone, nitric
acid, ammonia, and dust.

Oxygen is the most important of these constituents, for it is the part
that is necessary to support life. Yet, notwithstanding its importance,
it forms only about one-fifth of the entire bulk of the atmosphere.

Oxygen is a very interesting substance and many striking experiments
may be performed with it. If a lighted candle is thrust into a vessel
filled with oxygen, it burns very much more rapidly and brilliantly
than in air. A piece of wood with a mere spark on it bursts into flame
and burns brightly when thrust into oxygen, and some things that will
not burn at all in air, can be made to burn very rapidly in oxygen. For
example, if a piece of clock spring be dipped in melted sulphur and
then put into a jar of oxygen, after the sulphur has been set on fire,
the steel spring will take fire and burn fiercely. The heat produced is
so great that drops of molten steel form at the end of the spring, and
falling on the bottom of the jar, melt the surface of the glass where
they strike.

The other two substances found in pure air, nitrogen and argon, are
very much alike. They make up the remaining four-fifths of the air, and
are very different from oxygen in nearly every respect.

Nitrogen and argon resemble oxygen in being colorless, odorless, and
tasteless gases; and they are of nearly the same weight as oxygen,
argon being a little heavier and nitrogen a little lighter; but here
the similarity ends. Oxygen is what we call a very active substance.
As we have seen, it causes things to burn very much more rapidly in it
than in air. Nitrogen and argon, on the contrary, put out fire. If a
lighted candle is put into a jar of nitrogen or argon its flame will be
extinguished as quickly as if put into water.

We must now consider the impurities found in air. Of these the most
important is carbonic acid gas, or, as it is frequently called, carbon
dioxide. It is always produced when wood or coal is burned, and
is, of course, constantly being poured out of chimneys. It is also
produced in our lungs and we give off some of it when we breathe. It
is colorless, like the gases found in pure air, has no odor or taste,
and is considerably heavier than oxygen or nitrogen. In its other
properties it is much more like nitrogen than oxygen, for when a
candle is put into it the flame is extinguished at once. To find out
whether air contains carbonic acid gas, it is only necessary to force
it through a little lime water, in a glass vessel, and watch what
change takes place in the water. Fresh lime water is as clear as pure
water; but after forcing air containing carbonic acid through it, it
becomes turbid and milky. If the turbid water is allowed to stand for
a time, a white powder will settle to the bottom, and if we examine
this powder, we find it to be very much the same thing as chalk. While
it is true that air generally contains only a very small portion of
carbonic acid gas, there are some places in which it is present in such
large quantities as to render the air unfit for breathing. The air at
the bottom of deep mines and old wells often has an unusually large
proportion of this gas, which, because of its great weight, accumulates
at the bottom, and remains confined there. The presence of a dangerous
quantity of the gas in such places may be detected by lowering a candle
into it.




Why Does the Scenery Appear to Move When We Are Riding in a Train?


When you sit in a moving train looking out of the window it appears
as though the fields, the telegraph poles and everything else outside
were moving, instead of you. This is because our only ideas of motion
are arrived at by comparison, and the fact that neither you nor the
seats of the car or any other part of the inside of the car is changing
its position, leads you to the delusion that the things outside the
car are moving and not you. If you were to pull down all the curtains
and the train were making no noise at all, you would not think that
anything was moving. It would appear as though you were motionless just
as everything in the car appears so. When you turn then to the window,
and lift the curtain you carry in the back of your mind the idea of
being at rest and that is what makes it appear as though the fields and
everything outside were moving in an opposite direction.

This is particularly noticeable when you are in a train in a station
with another train on the next track. There is a sense of motion if one
of the trains only is moving and you feel that it is the other train,
because you are surrounded by objects in the car which are at rest,
and when you look out at the other train with this half consciousness
of rest in your mind, it appears as though the other train were moving
when as a matter of fact it is your train. If the delusion happens to
be turned the other way, it will appear as though you are moving and
the other is still. It depends upon what cause the impression starts
with.




Why Don’t the Scenery Appear to Move When I am in a Street Car?


If you are in a street car in the country and moving along fast you
will receive the same impression, especially in a closed car, because
you are looking out of one hole or one window. In an open car you
do not receive the same impression because your range of vision is
broader. You can and do, although perhaps unconsciously, look out on
both sides and the impression your mind gets through the eyes is not
the same. If you were to pull down all the storm curtains in a moving
open street car, and then look out of one little crack, you would think
the outside was moving. But if you stop to remember that you are moving
and not the things outside the car, then the impression vanishes. In
the city, of course, your brain is so thoroughly impressed with the
fact that houses and pavements do not move, and the cars move so much
more slowly, that it is difficult to make yourself believe otherwise.
The impression is more difficult always when you are moving through
or past objects with which you are perfectly familiar. It is all, of
course, a question of impressions.




Why Does the Moon Travel With Us When We Walk or Ride?


The moon does not really travel with us. It only seems to do so. The
moon is so far away that when we walk a block or two or a hundred, we
cannot notice any relative difference in the relative positions of the
moon and ourselves. When a thing is close at hand we can notice every
change in our position toward it, but when it is far away the change of
our position toward it is so slight that it is hardly perceptible. A
very good way to illustrate this is to ask you to recall the last time
you were in a railroad train looking out at the scenery in the country.
The telegraph poles rush past you so fast you cannot count them. The
cows in the pasture beside the railroad do not seem to go by so fast.
You can count them easily. The tree farther over in the next field does
not appear to be moving but slightly, while the church steeple which
you can see far in the distance, does not go out of sight for a long
time--in fact, seems almost to be moving along with you. The moon is
just like the church steeple in this case, except that it is so much
farther away that it seems to travel right with you. It is all due to
the fact as stated at the beginning of this answer, that the relative
positions of yourself and the moon are only slightly changed as you
move from place to place, so slight in fact as to appear imperceptible.




Is There a Man in the Moon?


The markings which we see on the face of the moon when it is full can
by a stretch of the imagination be said to form the face of a man. On
some nights this face appears to be quite distinct. If, however, we
look at the moon through a telescope, we see distinctly that it is
not the face of a man. Through a very large telescope we can see very
plainly that the marks are mountains and craters of extinct volcanoes.
It just happens that these marks on the moon, aided by the reflections
of the light from the sun, which gives the moon all the light it has,
make a combination that looks like a face.




Does the Air Surrounding the Earth Move With It?


This is one of the old puzzling questions which many a high-school
student has had to struggle with to the great amusement of the teacher
who asks for the information and such other scholars who have already
had the experience of trying to solve it.

To get at the right answer you have merely to ask one other question.
If the air does not revolve with the earth, why can’t I go up in
a balloon at New York, and stay up long enough for the earth to
revolve on its axis beneath me, and come down again when the city of
San Francisco appears under the balloon, which should be in about
four hours? If that were possible, travel would be both rapid and
comfortable, for then we could sit quietly in a balloon while the earth
traveling beneath us would get all the bumps.

No, the atmosphere surrounding the earth moves right along with the
earth on its axis. If it were not so, the earth would probably burn
up--at least no living thing could remain on it--since the friction of
the surface of the air against the surface of the earth would develop
such a heat that nothing could live in it.




Why Does Oiling the Axle Make the Wheel Turn More Easily?


If you look at what appears to be a perfectly smooth axle on a bicycle
or motor car through a powerful magnifying glass, you will find that
the surface of the axle is not smooth at all, as you may have thought,
but covered with what appear to be quite large bumps or irregularities
in the surface. If you were to examine the inside of the hub of the
wheel in the same way, you would find that it also is like that. Now,
when you attempt to turn a wheel on the axle without oil, these little
irregularities or bumps grind against each other, producing what we
call friction. As friction develops heat, the metal of the axle and the
hub expand and the wheel gets stuck.




What Made the Mountains?


There is no question but that at one time the surface of the earth was
smooth, i. e., there were no big hills and no deep valleys. That was
before the mountains were made. The earth was a hot molten mass that
began to cool off from the outside inward. It is still a hot molten
mass inside today. The outside crust became cooler and cooler and the
crust became deeper and deeper all the time. Then when there would be
an eruption of the red-hot mass inside, the earth’s crust would be
bulged out in some places and sucked in in others and would stay that
way. The bulged out place became a range of mountains and the sucked
in place became a valley. This process went on happening over and over
again until the crust of the earth became firmly set. Volcanos caused
some of these eruptions, as also did earthquakes. There are today
gradual changes occurring which to a certain extent change the outside
surface of the earth, and it is possible that new mountain ranges will
be produced in this way.




What Makes the Sea Roar?


The roar of the sea is a movement of the sea which causes the same kind
of air waves or sound waves that you make when you shout, excepting
that, of course, the vibrations do not occur so quickly in the sea and,
therefore, the sound produced is a low sound. It is no different in
any sense than the same noise would be if the same air waves could be
produced on the land away from the water.




Why Is Fire Hot?


When a fire is lighted it throws off what we call heat rays or waves.
These waves are very much like the waves of light which come from a
light or fire or the air waves which produce sounds. The rays of light
and heat which come from the sun are like the rays of light and heat
from a fire. Heat is of two kinds--heat proper which is resident in the
body, and radiant heat which is the kind which comes to us from the
sun or from a fire. This radiant heat is not heat at all, but a form
of wave motion thrown out by the vibrations in the ether. The heat we
feel is the sensation produced upon our skins when it comes in contact
with the waves created by the fire. Heat was formerly thought to be an
actual substance, but we know now that radiant heat is known to be the
energy of heat transferred to the ether which fills all of space and is
in all bodies also. The hot body which sets the particles of either in
vibration and this vibrating motion in the form of waves travels in all
directions. When these vibrations strike against our skin they produce
a heat sensation; striking other objects these vibrations may produce
instead of a heat sensation, either chemical action or luminosity. This
is determined by the length of the vibratory rays in each case.




When I Throw a Ball Into the Air While Walking, Why Does It Follow Me?


When you throw a ball into the air while moving your body forward or
backward, either slowly or fast, the ball partakes of two motions--the
one upward and the forward or backward motion of your body. The ball
possessed the motion of your body before it left your hand to go up
into the air because your body was moving before you threw it up, and
the ball was a part of you at the time.

If you are moving forward up to the time you throw the ball into the
air and stop as soon as you let go of the ball, it will fall at some
distance from you. Also if you throw the ball up from a standing
position and move forward as soon as the ball leaves your hand the ball
will fall behind you, provided you actually threw it straight up.

Of course, you know that the earth is moving many miles per hour on
its axis and that when you throw a ball straight into the air from a
standing position, the earth and yourself as well as the ball move
with the earth a long distance before the ball comes down again. The
relative position is, however, the same. We get our sense of motion by
a comparison with other objects. If you are in a train that is moving
swiftly and another train goes by in the opposite direction moving just
as fast, you seem to be going twice as fast as you really are. If the
train on the other track, however, is going at the same rate of speed
and in the same direction as you are, you will appear to be standing
still.

Going back to the ball again, you will find that it always partakes of
the motion of the body holding it in addition to the motion given when
it is thrown up.




What Good Are the Lines On the Palms of Our Hands?


It cannot be said that the lines on the palms of our hands are of any
great service to us. Indeed it is doubtful if they are of any value
in themselves, outside of the possible aid they may be in helping us
to determine the character of the surface of things which we grasp or
touch. It is possible that they aid in some slight degree in this way.
There is little doubt, however, that they are a result of the work the
hands are constantly called upon to do rather than contrived for any
particular service. The habitual tendency of the fingers in grasping
and holding things throws the skin of the palms into creases which
through frequent repetition make the lines of the palms permanent in
several instances.

The peculiarities of these lines or creases in various individuals
as to details and length and variations is the chief basis of the
so-called science of palmistry.




What Makes Things Whirl Round When I Am Dizzy?


The medical term that describes this condition of turning or whirling
is vertigo, which means in simple language “to turn.” There are two
kinds of dizziness--one where the objects about us seem to be turning
round and round and the other where the person who is dizzy seems to
himself to be turning round and round.

One cause of this is due to the fact that when you are dizzy the
eyes are not in complete control of the brain and the eyes moving
independently of each other look in different directions and produce
this turning effect on the brain, since each eye then sends a different
impression to the brain instantly.

The principal cause of the sense of dizziness is, however, the little
organ which gives us our power to balance and which is located near the
ears. Sometimes this organ becomes diseased and people affected in this
way are almost continually dizzy. Whenever this organ of balance is
disturbed we lose our idea of balance and the turning sensation occurs.

It is easy to make yourself dizzy. All you do is to turn round a few
times in the same direction and stop. In doing this you disturb the
little organ of balance and things begin to turn apparently before your
eyes. If you turn the other way you right matters again or if you just
stand still matters will right themselves. There is no great harm in
making yourself dizzy and very little fun.




Why Are the Complexions of Some People Light and Others Dark?


This difference in the complexions of people is due to the varying
amounts of pigment or coloring material in the cells of which the skins
of all animals is made up. Very light people have very little pigment;
very dark people, those with dark eyes and black hair, have a great
deal of this coloring material in their cells. A great many people are
neither light or very dark. They have less than the dark-complexioned
people and more than the light-complexioned people. When the hair
turns gray it is because the pigment has disappeared. As this is due
to the loss of this coloring material, dark-complexioned people turn
gray sooner than light-complexioned people. The structure of the skin
showing how these cells are made in layers can be seen by examining the
skin with a microscope.




What Makes Me Tired?


Men were wrong for a long time in their conclusions as to what produced
the tired feeling in us.

We know now that every activity of our body registers itself on the
brain. When we move an arm or leg a great many times we soon feel
tired. Every time you move your arm the movement is registered in the
brain, and after a number of these movements are registered the tired
feeling in the arm appears. It is said that every movement of any part
of the body really produces certain defective cells and that these
accumulate in the blood. When these reach a certain number the tired
feeling takes possession of us, and when we rest, the blood under
the guidance of the brain, goes to work and rebuilds these defective
cells. We know that a change takes place in the blood when we become
tired because, if you take some of the blood from an animal that shows
unmistakable signs of fatigue and inject it into an animal that shows
no tired feeling at all, the second animal will begin to show signs of
fatigue even though it is not active at all.

We used to think that being tired indicated that our bodies were in
need of food and that the way to overcome it was to eat a big meal.
We did not stop to think that even when we are hungry the human body
has sufficient food supply stored up to keep it going for days without
taking in new food. Of course, this mistake was made because we knew
that our power and energy came as a result of the food we took into our
systems, but this belief was exploded when it was found that a really
tired person could hardly digest food while tired, and that it is best
for people who are very tired to eat only a light meal.




Why Are Most People Right-Handed?


Most people are right-handed because they are trained that way. Being
right-handed or left-handed depends largely on how we get started in
that connection. When we are young we form the habit generally of
being either right-handed or left-handed, as the case may be. Most
people correct their children when it appears they are likely to
become left-handed, as we have come to think that it is better to be
right-handed than left, and that is the reason why most people are
right-handed. As a matter of fact, if we were trained perfectly, we
should all be both right-handed and left-handed also. Some people are
so trained and, when we refer to their ability to do things equally
well with both hands and wish to bring out this fact, we say they are
ambidextrous. It is not natural that one hand should be trained to do
things while the other is not.




Why Are Some Faculties Stronger Than Others?


All of our senses are capable of being developed so that our ability
along these lines would be about equal. The trouble is that we soon
begin to develop one or more of our faculties in an unusual manner at
the expense of the development of others. Many people have a keener
sense of observation than others because they have had more and better
training along that line. It is a pity that more attention is not given
to the development of the power of observation in children, because
it is one of the most valuable accomplishments that we can possess
ourselves of. With the sense of observation developed to the highest
degree, many of the other faculties need not be developed so strongly
because, if we notice every thing that it is possible for us to see,
we do not have the need of the development of other powers to the same
extent.

It is said that it would be possible to so train an infant and bring
him up to maturity with all his faculties developed and in practically
an even way. If we did that we would have a wonderfully intelligent
being.

[Illustration: Glazing plates.]

[Illustration: Decorating china cups.]




The Story in a Cup and Saucer


~HOW CHINA IS MADE~

Many different kinds of raw materials are required to produce the clay
from which china is formed, and these ingredients come from widely
separated localities. Clays from Florida, North Carolina, Cornwall and
Devon. Flint from Illinois and Pennsylvania. Boracic acid from the
Mojave Desert and Tuscany. Cobalt from Ontario and Saxony. Feldspar
from Maine. All these and more must enter into the making of every
piece.

[Illustration: Grinders for reducing glazing materials.]

These materials are reduced to fine powder and stored in huge bins.
Between these bins, on a track provided for the purpose, the workmen
push a car which bears a great box. Under this box is a scale for
weighing the exact amount of each ingredient as it is put in, for too
much of one kind of clay or too little of another would seriously
impair the quality of the finished china.

[Illustration: Mill for pulverizing materials.]

From bin to bin this car goes, gathering up so many pounds of this
material and so many pounds of that, until its load is complete. Then
it is dumped into one of the great round tanks called “blungers,” where
big electrically driven paddles mix it with water until it has the
consistency of thick cream. From the blungers this liquid mass passes
into another and still larger tank, called a “rough agitator,” and is
there kept constantly in motion until it is released to run in a steady
stream over the “sifters.”

These sifters are vibrating tables of finest silk lawn, very much
like that used for bolting flour at the mills. The material for
china making strains through the silk, while the refuse, including
all foreign matter, little lumps, etc., runs into a waste trough and
is thrown away. From the sifters the liquid passes through a square
box-like chute, in which are placed a number of large horseshoe
magnets, which attract to themselves and hold any particles of harmful
minerals which may be in the mixture.

After leaving the magnets the fluid is free from impurities, and is
discharged into another huge tank called the “smooth agitator.” While
the fluid is in this tank a number of paddles keep it constantly in
motion.

[Illustration: Pressing the water from the clay.]

From the smooth agitator the mixture is forced under high pressure into
a press where a peculiar arrangement of steel chambers packed with
heavy canvas allows the water to escape, filtered pure and clear, but
retains the clay in discs or leaves weighing about thirty pounds each.
From the presses this damp clay is taken out to the “pug mills,” where
it is all ground up together, reduced to a uniform consistency, and
cut into blocks of convenient size. It is now ready to use. Automatic
elevators carry it to the workmen upstairs.

[Illustration: Molding Dishes. The racks to the left are full of molds
on which the clay is drying.]

[Illustration: Molding sugar bowls and covered dishes.]

~HOW THE DISHES ARE SHAPED~

The exact process of handling the clay differs with articles of
different shapes. Some are molded by hand in plaster of paris molds of
proper shape, while others are formed by machine. To make a plate, for
example, the workman takes a lump of clay as large as a teacup. He lays
this on a flat stone, and with a large, round, flat weight, strikes it
a blow which flattens the material out until it resembles dough rolled
out for cake or biscuits, only instead of being white or yellow it is
of a dark gray color. A hard, smooth mold exactly the size and shape
of the inside of the plate is at hand. Over this the workman claps the
flat piece of damp clay. Then the mold is passed on to another workman,
who stands before a rapidly revolving pedestal, commonly known as the
potter’s wheel. On this wheel he places the mold and its layer of clay.
He then pulls down a lever to which is attached a steel scraper. As the
plate rapidly revolves, this scraper cuts away the surplus clay, and
gives to the back of the plate its proper form. The plate, still in its
mold, is placed on a long board, together with a number of others, and
shoved into a rack to dry. One workman with two helpers will make 2,400
plates per day. It is fascinating to watch the molders’ deft hands at
work swiftly changing a mass of clay into perfectly formed dishes. Such
skilled workmen are naturally well paid.

[Illustration: Interior of a kiln showing how the “saggers” are packed
for firing.]

When the clay is sufficiently dry, the plate is taken from its mold,
the edge smoothed and rounded, and any minor defects remedied. It
is then placed in an oval shaped clay receptacle called a “sagger,”
together with about two dozen of its fellows, packed in fine sand,
and placed in one of the furnaces or kilns. Each kiln will contain on
an average two thousand saggers. When the kiln is full the doorway
is closed and plastered with clay, the fires started, and the dishes
subjected to terrific heat for a period of forty-eight hours. The
fuel used is natural gas, piped one hundred miles from wells 2,000
feet deep. Natural gas gives an intense heat, and yet is always under
perfect control--features which are vital in producing uniformly good
china.

When the plate is taken from the kiln after the first baking, it is
pure white, but of dull, velvety texture, and is known as bisque ware.

In order to give it a smooth, high finish, the plate is next dipped
into a solution of white lead, borax and silica, dried, placed in a
kiln and again baked. When it is taken out for the second time it
has acquired that beautiful glaze which so delights the eye. In this
condition it is known as “plain white ware,” and is finished, unless
some decoration is to be added.

[Illustration: Taking the dishes from a kiln.]

~HOW CHINA IS DECORATED~

Most people are surprised to learn that the greater part of the
gold which adorns dishes is put on by a simple rubber stamp. Two
preparations of gold are used. One is a commercial solution called
“liquid bright gold,” the other is very expensive, and is simply gold
bullion melted down with acids to the right consistency.

Decorating in colors is now done almost exclusively by decalcomania art
transfers. These are made principally in Europe.

After the gold and colors are applied, the China must again go through
the oven’s heat for a period of twelve hours. Then the piece finished
at last, is ready to grace your table. The dull gray clay has become
beautifully finished china, which will delight alike the housekeeper
and her guests.




How Do Birds Find Their Way?


The most interesting phase of the movement of animals from place to
place is found in the flight of birds during the spring and fall. In
the spring the birds come north and in the fall they go south. This is
called “migration” and the reason given for the ability of some birds
to come back every year to build a nest in the same tree is usually
attributed to the “instinct of migration,” and yet that is more a
statement of fact rather than an explanation of the wonderful ability
of the birds to do this.




How Does a Captain Steer His Ship Across the Ocean?


Man, the most intelligent animal, can also find his way about, but
he has had to learn to do this step by step. When an explorer first
travels into the unexplored forest, he carries a compass which tells
him in what direction he is traveling, but this is not sufficient to
tell him the exact path he came and return the same way. In order that
he may do this, he must make marks on the trees and other objects
to find his way back. When these marks are once made, other men can
follow the path by their aid, and eventually a path becomes worn so
that men can find their way back and forth without the aid of the marks
especially.

A trained ship captain can take his ship from any port in the world to
another port. He can start at New York City and in a given number of
days, according to how fast his ship can travel, land his passengers
and cargo in the port of London or Johannesburg, South Africa, or at
any desired port in China, Japan or any other country. But he cannot do
this by any kind of instinct. He takes his directions from information
that was furnished him by some one who went that way before him--some
other captain of a vessel who made marks in his book of his position
in relation to the sun and stars. This is practically the same as the
traveler in the forest who made marks on the trees to make a map of the
way back and forth. Even with these charts, compasses and other guiding
marks, however, man, even though he is the most intelligent of all the
animals, makes very grave mistakes and sometimes brings disaster upon
himself and the lives in his care.




Why the Birds Come Back in Spring?


The birds, however, have no charts or compasses to guide them. We do
not know as yet absolutely what it is that enables the bird to find its
way back and forth to the same spot year after year. As nearly as we
have been able to ascertain, the birds after they mate and build their
first nest and bring up their first family, develop a fondness for that
particular spot which is much the same as the instinct in man which we
call the “homing instinct.” Man becomes attached to one particular spot
which he calls home and wherever he is thereafter, he is very likely to
think of the old locality when he thinks of home, and there are very
few of us but have yearnings to go back to the old “home locality”
every now and then. The environment in which a bird or human being is
brought up generally becomes to a greater or less extent a permanent
part of him in this sense.




Why Do Birds Go South in Winter?


We know why birds go south in the winter. The necessity of finding
food to live upon has everything to do with that. As food grows
scarce towards the end of summer in the farthest northern places where
birds live, the birds there must find food elsewhere. They naturally
turn south and when they find food, they have to divide with the birds
living there. The result is that soon the food becomes scarce again
and both the new-comers and the old residents, so to speak, are forced
to seek places where food is plentiful. So both of these flocks, to
use a short term, fly away to the south until they find food again
and encounter a third flock or group of the bird family crowding the
locality and exhausting the food supply. So in turn each flock presses
for food upon the one in the locality next further to the south until
we have a general movement to the south of practically all the birds
until they reach a point where the food supply is sufficient for all
for the time being.




Why Don’t the Birds Stay South?


The result of all this is that the south-land is crowded with birds of
all kinds and the food supply is enough for all. But soon in following
the laws of nature in birds, as in other living things, comes the time
for breeding. The south-land is warm enough for nesting and hatching,
but it is so crowded that there wouldn’t be enough food for all the old
birds and the little ones too and so the birds begin to scatter again.
Just think of what would happen in the south-land if all the birds that
stay there in the winter built their nests there and brought up a new
family. A bird family will average four young birds, so that if all the
bird families were born and raised in the south the bird population
would quickly multiply itself by three and there would be the same old
necessity of traveling away to look for food. To avoid this the birds
begin to scatter to their old homes before the breeding season begins.




How Do They Find the Old Home?


The return of the birds to their old homes and how they find their
way back to the same spot every year, to do which they must sometimes
travel thousands of miles, is one of the most marvelous things in
nature and has not as yet been satisfactorily determined. The nearest
approach we have to a satisfactory answer to this is that birds do have
a memory, that they can and do recognize familiar objects, and that
their love for the old home causes them to fly to the north until they
recognize the landmarks of their former habitation. In this it is said
that the older birds--those who have gone that way before--lead the
flocks and show the way.

There is no doubt that birds have a more perfect instinct of direction
than man. They can follow a line of longitude almost perfectly, i.e.,
they can pick out the shorter route by instinct, and this is, of
course, a straight line. They just keep on going until they come to the
familiar place they call home and then they stop and build their nests.
That it is not memory and sight of places alone that guides the birds
is shown by the fact that some birds when migrating fly all night when
there is no light by which to recognize familiar objects.




Why Do Birds Sing?


The song of the birds is a part of the love-making. The male bird is
the “singer,” as we call them at home, when we think of the canary in
the cage near us. The male bird sings to his mate to charm her and to
further his wooing. This wooing goes on after the eggs have been laid
in the nest and while the mother bird is keeping them warm until they
hatch out, but almost instantaneously with the birth of the little
birds, the song of the male bird is hushed. Take the case of the
nightingale. For weeks during the period of nest-building and hatching
he charms his mate and us with the beautiful music of his love song.
But as soon as the little nightingales come from the eggs, the sounds
which the male nightingale makes are changed to a gutteral croak, which
are expressive of anxiety and alarm, in great contrast to the song
notes of his wooing. And yet, if you were at this period--just after
the birds are born, and when his song changes--to destroy the nest
and contents, you would at once find Mr. Nightingale return to his
beautiful song of love to inspire his mate to help him build another
nest and start all over again to raise a family.




What Causes an Arrow to Fly?


It is caused by the power generated when you bend the bow and string
of the bow and arrow out of shape. The bow and string have the quality
of elasticity which causes a rubber ball to bounce. When you force
anything elastic out of shape, this quality in it makes it try to
get back to its natural shape quickly. In doing this it acts in the
direction which will take it back to its normal shape most quickly. The
arrow is fixed on the string in a way that will not interfere with the
bow and string getting back to its shape and, when they bounce back,
the arrow goes with it. The real cause for the arrow’s flight, however,
comes not from the bow, because the bow cannot put itself out of
shape, but comes from the person who causes it to be out of shape and,
therefore, the person who pulls the string back really causes the arrow
to fly.




Why Do Children Like Candy?


Children crave candy because the sugar which it contains largely is in
such a condition that it is the most suited of all our foods for quick
use by the body. It is actually turned into real energy within a few
minutes after it is eaten.

All the things we eat are for the purpose of supplying energy to our
bodies to replace the energy that our daily activities have dissipated.
Nature takes the valuable parts of the foods we eat and changes them
into energy. The waste parts she throws off. Many things we eat have
little real value as food and many also nature has to work upon a long
time before their food value is available in energy. Sugar, however,
represents almost energy itself.

Children are, of course, more active than grown-ups. They are never
still. They are, therefore, almost always burning up or using up their
energy. They are also, therefore, almost always in need of food that
can be made into energy, and as sugar does this almost more quickly
than any other food, nature teaches the children to like candy or
sweets.




Why Does Eating Candy Make Some People Fat?


Eating as much as one can of anything at any time will produce fat,
provided you do not do sufficient physical work or take enough exercise
to counteract the effect of generous eating. When you see a person who
eats a great deal and is growing fat, you may know that he or she is
not taking sufficient bodily exercise to work off the energy produced
by the body from the food that has been eaten. When this happens the
energy in the form of fat piles up in various parts of the system.
Candy will do this more quickly than any other thing we eat because it
contains so much sugar and because sugar is so easily changed by our
system into usable energy. You generally find a fat person who eats
much candy to be a lazy person.




What Makes Snowflakes White?


A snowflake is, as you are no doubt aware, made of water affected in
such a way by the temperature as to change it into a crystal. Water, of
course, as you know, is perfectly transparent. In other words, sunlight
or other light will pass through water without being reflected. A
single snow flake also is partially transparent, i.e., the light will
go through it partially, although some of it will be reflected back.
When a drop of water is turned into a snowflake crystal, a great many
reflecting surfaces are produced, and the whiteness of the snowflake is
the result of practically all of the sunlight which strikes it being
reflected back, just as a mirror reflects practically all the light or
color that is thrown against it. If you turn a green light on the snow,
it will reflect the green light in the same way. When the countless
snow crystals lie on the ground close together, the ability to reflect
the light is increased and so a mass of snow crystals on the ground
look even whiter than one single snowflake.




What Makes the White Caps on the Waves White?


In telling why the snowflake is white we have practically already
answered this question also. Instead of little crystals formed from the
water, the foam produced by the waves of the ocean are tiny bubbles
which have the same ability to reflect the light as the snow crystals.




What Good Can Come of a Toothache?


Very few of us realize that an aching tooth is a good thing for us,
provided we have it attended to and the ache removed. Any one who has
had toothache will hardly agree that there can be a blessing attached
to this excruciating pain.

But the good comes from the warning it gives us of the condition of our
teeth on the inside of our mouths. The arrangement of the interior of
the mouth and the use we make of it in passing things into our systems,
favors very much the development and increase of microbes, and when
they once get in they are difficult to remove. It is said that the
greatest percentage of cases of stomach trouble come from teeth which
are in bad condition and that a very large percentage of people who
have bad teeth are in grave danger of blood poisoning or other troubles
due to the microbes. When these microbes lodge in the mouth, they find
conditions favorable to their development when there are bad teeth, and
spread through the system.




How Can Microbes Spread Through the Body?


The various parts of the body, including the gums, are connected by
a lymphatic tissue, which is practically a series of canals. If the
teeth are not properly attended to and kept in good condition, both as
to cleanliness and repair, the microbes or germs collect on the gums
and teeth, and increase in numbers. Soon the mouth is over-populated
with microbes and are pushed off the gums or teeth into the lymphatic
canals, where they succeed in developing a disease in your body.

Now the ache in the tooth becomes a blessing very promptly if it
begins soon after the tooth begins to decay, because in that event the
dentist is visited and the tooth filled or pulled. Therefore, while
it hurts terribly, it might be well to remember that a toothache is a
timely warning of danger which, if not heeded, will likely develop into
something quite serious.




What Causes Toothache?


The ache comes when the tiny nerve at the heart of the tooth is
exposed to the air. When the tooth begins to decay, it starts to do so
generally from the outside, and after the decaying process has gone far
enough, it reaches the nerve in the tooth, which aches when exposed to
the air. The ache is the signal which the nerve sends to the brain that
there is an exposure and a cry for help.




Of What Use Are Pains and Aches?


All pains and aches are helpful in sounding a warning. A headache may
be the result of improper sleep and rest and, therefore, warns us to
take the needed rest or sleep. A pain in the stomach is only nature’s
way of telling us that we have been unwise in our eating and drinking.
As a matter of fact, short though our lives are, they would probably
be still shorter, on the average, if it were not for pains and aches,
because without these warnings we would never have sense enough to stop
doing the things we should not do if we lived normally.




What Causes Earache?


Earache is caused by the nerves in the ear being affected by something
either from within or without which produces a swelling of the parts
immediately adjacent to the nerves in the ear, and which press against
the nerves; as the nerves cannot go any place else they send a warning
to the brain that they are being crowded and pressed against. The pain
you feel is the nerve in the ear warning the brain that something is
wrong in the ear.




What Is Soap Made Of?


Soap is not a very modern product, although we have rarely read of soap
in olden times. As long ago as two thousand years, the Germans had an
ointment which was made in practically the same way as we now make
soap. A soap factory was engaged in making soap in France in 1000 A. D.

Even before soap was manufactured, people knew that ashes of some
plants, when mixed with water, gave it a peculiar, smooth, slippery
feeling, and added to the cleansing qualities of water. Although they
did not know it, this was due to the soda of potash which was in the
ashes. Pure soda and potash both have excellent qualities for cleaning,
but are likely to injure the skin, and other things coming in contact
with them.

Soap is made by boiling together oil or fat and “caustic” soda or
potash. Caustic soda is a substance made from sodium carbonate by
adding slaked lime to a solution of it. The slaked lime contains
calcium in combination with hydrogen and oxygen, and is known in
chemistry as calcium hydrate. When calcium hydrate is added to a
solution of sodium carbonate, the sodium present combines with the
oxygen and hydrogen to form a compound, variously called sodium
hydrate, sodium hydroxide, or caustic soda. A similar compound of
potassium is formed when the same kind of lime is mixed in a solution
of potassium carbonate. In both cases the calcium is converted into
calcium carbonate, which is not soluble in water and settles to the
bottom; but the caustic soda or potash is dissolved.

The word “caustic” means to burn. Both will burn the skin if allowed to
touch the skin for a short time.

The fats used for making soap consist of glycerine, in chemical
combination with what are called fatty acids. When these fats are
boiled with caustic soda, or caustic potash, the fat is decomposed; the
fatty acid combines with the sodium or potassium to form soap and the
glycerine is left uncombined.

In modern soap factories the manufacture is carried on in large iron
vessels. Some fat and oil are put into the vessel and a little lye,
which is really caustic soda or potash, is added and the mixture
boiled. The fat and the lye combine very quickly and form a whitish
fluid. More lye is now added and the boiling continued. This process
is repeated until nearly all the oil or fat has combined with the lye.
If yellow laundry soap is being made, some rosin is put in, and this
gives the yellow color. If toilet soap is being made, common salt is
put in instead of rosin. The addition of the salt has the effect of
separating the water and the glycerine from the soap. The soap rises to
the surface and is skimmed off. As soon as the separation is complete,
and the soap is then cut or pressed into cakes after it has become hard.

Soaps referred to above are the ordinary hard soaps. In making soft
soaps no salt is added to separate the soap from the liquid. As the
water and glycerine do not separate from the soap, the entire mixture
remains of a soft consistency. Soft soap is also made with a lye, that
is obtained from wood ashes. The ashes are placed in barrels and water
poured upon them. The water drips down through the ashes in the barrel
and dissolves the potash contained in them, making lye or caustic
potash. This lye is then in liquid form and is mixed and boiled with
grease or fat to make soap.

There are many different fats used in soap making. Palm oil is perhaps
the most common, but tallow, olive oil, cotton seed oil, and many other
fats are used. The hardness of the soap varies with the kind of fat
and lye used. Palm oil or tallow soap is very hard, and other oils are
sometimes mixed with it to soften it.

These are the main facts connected with the making of soaps. There may
appear to be different kinds all of which look and smell differently.
The difference in them is largely due to the presence of different
perfumes and coloring matters.

[Illustration: INDIAN SENDING MESSAGE WITH SMOKE SIGNALS.

The savage Indians found their system of smoke signals quite effective
in sending messages from place to place. With a good burning fire
before him, and a blanket or shield at hand, the Indian was equipped
to send his messages. The code consisted of the varying kinds of smoke
clouds produced. These were made large or small by covering the fire
at intervals with the blanket or shield, thus making interruptions of
various lengths in the rising clouds of smoke. By dropping moss or
other things into the fire, he made the smoke clouds either light or
dark at will.]




The Story in a Telegram


How Man Learned to Send Messages.

From the time when man had learned to protect himself from the beasts
of the forest, and thus was able to move about more freely, and live by
himself rather than remain with the tribe, he has found it necessary to
send messages.

One of the most interesting of the early methods for sending messages
was the Indian way of smoke signalling with the simple equipment of a
fire with its rising column of smoke and a blanket or shield. Messages
were sent, relayed, received and answered, at points hundreds of miles
apart. Among savages still found in remote parts of the earth this and
other primitive methods are still in use. In the wilds of Africa to-day
at points where the electric telegraph service has not yet penetrated,
the natives by the simple method of beating drums, which can be heard
from one relay point to another, are able to send the “news of the day”
across the country with marvellous rapidity. In some parts of South
America, the natives long ago discovered that the ground is a good
conductor of sound and send their messages almost at will, making their
signals by tapping against poles which they have planted in the ground
at various points and which constitute both their sending and receiving
instruments.

The Signal Corps in the army uses flags for sending messages, where
the telegraph is not available, the flags being of different colors,
and the signals are produced by waving the flags in different ways.
The army heliograph is also used as a telegraph line--a mirror which
reflects the sun’s rays in a manner understood by a prearranged code.
These and other similar methods are merely elaborations of devices
developed and used by the savages as a solution of the ever present
need of sending a message to some other point.

[Illustration: THE FIRST MESSENGER BOY

THE GREEK RUNNER.

In this picture we see the Greek Runner on the last leg of his journey
and the man to whom he is to deliver the message waiting for him. This
method of sending messages was not very fast, although the runners were
picked because of their speed and endurance.]

[Illustration: THE PONY TELEGRAPH.

Here we see the fast riders of the Pony Telegraph, which increased the
speed of delivering messages quite a good deal, but, of course, there
was danger of losing the message to enemies or through accident, so
that it might be difficult under such circumstances to send a secret
message or to even be certain that it would arrive at destination.]

[Illustration: IT IS EASY TO CALL A TELEGRAPH MESSENGER...

RINGING THE CALL BOX.]

The great Marathon runner was nothing more or less than a telegraph
messenger hastening with his written message, from the man who
delivered it to him, to its destination, and his work was harder than
that of the messenger boy to-day, for he not only had to deliver the
message himself to its destination, but had to run fast all the way or
lose his job.

The messenger on foot finally gave way to the Pony Telegraph, which not
only shortened the time necessary to deliver a message, but marked the
beginning of a system.

[Illustration: MESSENGER BOYS WITH BICYCLES WAITING THE CALL.]


How Does a Telegram Get There?

The next time your daddy takes you down to the office, ask him to show
you the telegraph call box. When you see it, you will perhaps not think
that by merely pulling down the little lever you can so start things
going that, if you wish, you can cause men who are on the other side
of the earth to work for you in a few minutes, and to make little
instruments all along the way which, with their other equipment, have
cost millions of dollars, click, click, click at your will.

[Illustration: ...BUT MANY TELEGRAPH EMPLOYEES MUST WORK...

Here we see the messenger calling at the office from which the call box
registered a call and receiving the telegram to be taken by him to the
central office to be put on the wire.]

[Illustration: When the messenger gets back to the office, he hands the
message to the receiving clerk who stamps it, showing the exact time
received and sends it by pneumatic tube to the operating room.]

Sooner or later during the day your father will be wanting to send a
telegram. He steps to the call box, pulls the little lever and goes
back to his desk. In a few minutes, sometimes before you realize it,
the little blue-coated messenger appears and says “Call?” Father
hands him a telegraph blank on which he has written the message, the
messenger takes off his cap, puts the message inside and the cap back
on his head and away he goes on his bicycle as fast as his legs can
pedal, to the central office, to which point you follow him to see what
he does with the message.

If you had been at the telegraph office instead of your father’s
office, you would have seen one of these boys start off on his wheel to
get the message your father wished to send. When the little lever on
the call box is pulled down, it is pulled back by a spring which sets
some clock work going which sends a signal over the wire on a circuit
which runs out from a register at the main office. The register has a
paper tape running through it, and the signal from the call box appears
as a series of dots on the tape. The clerk knows from the number and
spacing of the dots that it was your father that called and not some
other business man whose box might be on the same circuit.

[Illustration: ...BEFORE THE TELEGRAPH SERVICE IS POSSIBLE AND...

We have now followed the telegram to the point where it is to start
on its real journey. Here we see the operator preparing to send the
message. He first must “get the wire.” By this is meant to get a
through connection to the town where the message is to be delivered.
Each office along the line has a signal. The other operators can hear
the call, but since it is not their signal, they pay no attention.
Almost immediately, however, the operator at the delivery point hears
the signal. He signals back “I I” and repeats his own office call,
which means “I hear you and am ready.” The message is then ticked off,
until finished and the operator at the delivery point signals “O. K.,”
together with his personal signal, which means he has received the
whole message and has it down on paper.]

[Illustration: Here we see the operator at the delivery office. She
has translated the dots and dashes as they came to her over the wire
into plain words on a regular telegraph blank, putting down the time
received, the amount to be collected, if it is a “collect” message, or
marking it “Paid” if it was so sent. She has handed it to one of the
blue-clad messengers in her office who starts off at once to deliver
it. The operator has also made a copy of the message for the office
files.]

[Illustration: ...THE TELEGRAM ARRIVES AT DESTINATION

Here we see the messenger delivering the telegram to the person to
whom it is addressed. It may be good news or bad news for the person
receiving it, but it is all in the day’s work for the messenger boy.
But let us see how many people have to work to deliver the message. We
have followed it through from the original call box. First there was
the messenger who came for it, then the receiving clerk, the sending
operator and the operator who receives it and last of all the messenger
boy who delivered it. This does not take into account the men who must
look after the many miles of wires, the machinery which supplies the
current, or the great army of men who are constantly laying new wires
so that you can send a telegram from almost anywhere to any other
place.]

The operators you have seen working in these pictures are Morse
operators. They send the message by Morse Code in dots and dashes
which are sent over the wire as electric impulses. At the other end
the message is read by listening to the clicks the sounder makes as
it receives these same electric impulses. This is the simplest way of
telegraphing.

The number of messages sent between two big cities in a day is
tremendous--many more than could be transmitted over one Morse wire.
Many wires would be needed. But wire costs money, so ingenious men
set to work to find some way to send more than one message over a
single wire at the same time. They succeeded. There is now the duplex
telegraph, which sends a message each way simultaneously over a single
wire, the quadruplex, which sends two messages each way simultaneously
over a single wire. Last but not least there is the multiplex, which
sends four messages each way simultaneously over a single wire.
This seems almost unbelievable, but it is done. In the case of the
duplex and quadruplex, the different messages are sent by currents
of different strength, and by changing the direction of the current.
Receiving instruments are designed so as to separate the messages by
being affected only by the currents of certain strength or polarity,
as the direction of flow is termed. It can easily be seen that by
these ingenious devices, the telegraph company saves many thousands
of dollars in the miles and miles of wire, and hundreds of telegraph
poles which would be required if all the messages had to be sent over a
simple Morse wire, one message only upon the wire at a time.

[Illustration: THE WONDERFUL ELECTRIC TELEGRAPH SYSTEM...

In this picture we see the interior of a telegraph office along the
line of a railroad. The operator has her hand on the “key” or sending
instrument. At her left in a stand called the resonator, is the
receiving instrument called the “sounder” which clicks off the message.
In front of her is an instrument called the “relay.” Current from two
of the batteries goes through the key when it is pressed down, through
the relay and out on to the wires of the pole line, then through the
relay of the receiving operator at the other end, (see picture on
opposite page) through his key and through two more batteries to the
ground. The earth forms the return wire of an electric circuit when
both keys are “closed” or pressed down. You know all electricity has to
flow in a closed circuit. The “sounder” has to make good strong clicks
to be understood, and the current after it has gone through miles of
wire and ground may not be strong enough so the sounder is put on a
local circuit of its own, with a special battery. In this circuit is a
contact maker which is part of the relay. When the key is pressed down
and current flows over the wires on the poles and through the relays,
the magnets of the relay pull on a little piece of metal called the
“armature,” which makes a contact and closes the local sounder circuit,
so current from the single local battery can flow up through the
magnets of the sounder and back to the battery. This makes the sounder
click. When the key is released, the relay armature is pulled back by
a spring and breaks the circuit of sounder, which then emits another
click. By the number and duration of the clicks and the time between
them, the receiving operator knows the meaning of the signal. The Morse
Code, which is used throughout the United States, is shown on next
page.]

[Illustration: ...SENDS MESSAGES THOUSANDS OF MILES INSTANTANEOUSLY

  MORSE TELEGRAPH CODE

  Letters  Morse
  A        · --
  B        -- · · ·
  C        · ·  ·
  D        -- · ·
  E        ·
  F        · -- ·
  G        -- -- ·
  H        · · · ·
  I        · ·
  J        -- · -- ·
  K        -- · --
  L        ----
  M        -- --
  N        -- ·
  O        ·  ·
  P        · · · · ·
  Q        · · -- ·
  R        ·  · ·
  S        · · ·
  T        --
  U        · · --
  V        · · · --
  W        · -- --
  X        · -- · ·
  Y        · ·  · ·
  Z        · · ·  ·
  &        ·  · · ·

  Numerals

  Figures  Morse
  1        · -- -- ·
  2        · · -- · ·
  3        · · · -- ·
  4        · · · · --
  5        -- -- --
  6        · · · · · ·
  7        -- -- ·
  8        -- · · · ·
  9        -- · · --
  0        ----

  Punctuations

  . Period          · · -- -- · ·
  : Colon           -- · -- · ·
  ; Semicolon       · · ·  ·  ·
  , Comma           · -- · --
  ? Interrogation   -- · · -- ·
  ! Exclamation     -- -- -- ·
  - Fraction Line   ·
  ¶ Paragraph       -- -- -- --
  () Parenthesis    · -- ·· --]

The multiplex telegraph is truly a marvellous invention. It has been
developed by the engineers of the Western Union Telegraph Co. working
with the engineers of the Western Electric Company. The principle
on which this instrument works is that if separate instruments are
given connection with the wire one after the other during very short
intervals of time, the effect is as though the wire were split up, and
each instrument works just as if it alone were on the wire. Not only
does the multiplex telegraph thus send four messages in one direction
and four messages in the opposite direction, simultaneously over a
single wire, thus keeping no less than sixteen operators employed on
one wire, four sending and four receiving at each end, but each message
instead of being sent by the ordinary Morse key, is written upon a
typewriter keyboard at one end of the line and appears automatically
typewritten at the other end.

If you live in a big city, go into one of the larger branch offices
of the Western Union Telegraph Co. and ask to see printing telegraph.
Most of the large branch offices communicate with the general operating
department in the city by means of what they term “short line
printers,” which are instruments on which the message is written upon a
typewriter keyboard and appears typewritten at the other end.


Who Invented the Electric Telegraph?

It is hard to say just how the telegraph originated in the mind of men.
We have already shown how the savages sent signals over distances by
means of the smoke rising from his fire. Every boy and girl has used a
little mirror, held in the sun to flash a bright spot here and there.
This principle has been used by the army to signal at distances. The
sun’s rays are flashed from a small mirror, long and short flashes
indicating the dashes and dots of the Morse telegraph code.

[Illustration: PROFESSOR S. F. B. MORSE, INVENTOR OF THE TELEGRAPH.]

Progress towards the perfection of the electric telegraph began with
the first researches of scientists into the natural laws which govern
that great natural agent, electricity. Clever, painstaking men,
studying and experimenting for the love of the work, discovered bit
by bit how to control the force. Stephen Gray with his Leyden jars,
which stored up a charge of electricity, inspired Sir William Watson to
experiment, and he sent current from one jar to another two miles away.


The First Suggestion of the Electric Telegraph.

For a long time no one thought that this opened the way for the making
of a useful servant for man. In 1753 this thought occurred to an
unknown man in Scotland, who wrote a letter to a newspaper suggesting
that messages be sent by electric currents.

One of his schemes was that there should be a light ball at the
receiving end of the wire which would strike a bell when it felt
the electric impulse come over the wire from the Leyden jar, and by
devising a code depending upon the number of strokes of the bell and
the time between them, he suggested that messages could be sent and
interpreted. Some believe this man to have been a doctor named Charles
Morrison of Greenock, Scotland. Whoever he was, he suggested a method
which comes very near to being that in use to-day.

The difficulty with proceeding on this suggestion was that the current
from the Leyden jar was static electricity, which has not the strength
nor can it be controlled as can the current of low potential which
is used to-day. Volta discovered this new and more stable form of
electricity and many different men labored investigating what could
be accomplished with it. The names of Sir Humphry Davy and Michael
Faraday are inseparably connected with this advance. It was Oersted’s
and Faraday’s discovery of the connection between electricity and
magnetism, and how an electric current may be made to magnetize a piece
of iron at will, that really opened the way for the invention of the
telegraph we know to-day.


The First Real Telegraph.

But before the much greater practical value of Volta’s current was
discovered, one man developed a real telegraph which worked with
electricity of the static kind, produced by friction. This man was
named Sir Francis Ronalds. He worked along the lines laid down by the
unknown Scotchman, whom we have supposed to be Charles Morrison. The
machine he built and operated in his garden at Hammersmith utilized
pith balls, which actuated by the charge of static electricity sent
along the wire caused a letter to appear before an opening in the dial.
When perfected he offered it to the British Government, who refused
it. They were very stupid in their refusal, for they said “telegraphs
are wholly unnecessary.” Sir Francis Ronalds’ invention cost him much
care, anxiety and money. He lived to see the more practical voltaic
current taken up by others and put to successful use. Being unselfish
he rejoiced that others should succeed where he had failed.


Two Men who Invented our Telegraph almost Simultaneously.

The telegraph, working on the electro-magnetic principle, as used
to-day, was developed almost simultaneously on the two sides of the
Atlantic Ocean. In England Sir Charles Wheatstone and Sir William
Fothergill Cooke worked out a practical method and instruments, which
with few changes, are in use to-day. Cooke was a doctor and had
served with the British army in India. Wheatstone was the son of a
Gloucester musical instrument maker. The latter was fond of science and
experimented continually with electricity and wrote about it and other
scientific subjects. As a result of his work he was made a professor
at King’s College. There he conducted important researches and tests,
among which was one which measured the speed at which electricity
travels along a wire. So Cooke, who was a doctor and a good business
man, entered into partnership with the scientist Wheatstone, and
together they completed their invention. It was first used in 1838
on the London and Blackwall Railway. At first it was expensive and
cumbersome, using five lines of wire. Later this number was reduced
to two, and in 1845, an instrument was devised which required but one
wire. This instrument, with a few minor changes, is the one in use
to-day in England.

While these two men were working in England, an American artist, S. F.
B. Morse, was studying and experimenting in the United States along his
own lines but with the same end in view, namely to produce instruments
which would satisfactorily send messages over a wire by electricity.


An American, however, is given the honor of First by Slight Margin.

Morse was born in Charlestown, Massachusetts, in 1791. He was gifted as
an artist, both in painting and sculpture, and in 1811 went abroad to
England to study. While on a voyage from Havre to America in 1832 he
met on board ship a Dr. Jackson, who told him of the latest scientific
discoveries in regard to the electric current and the electro-magnet.
This set Morse to thinking and after three years’ hard work on the
problem he produced a telegraph which worked on the principle of the
electro-magnet. With the apparatus devised by Morse and his partner
Alfred Vail, a message was sent from Washington to Baltimore in 1844.

There has been some question as to whether Morse or Wheatstone first
invented a workable telegraph. As will be evident from this history,
the telegraph in principle was a gradual development, to which many
minds contributed. To Morse, however, the high authority of the
Supreme Court of the United States has given the credit of being
the first to perfect a practical instrument, saying that the Morse
invention “preceded the three European inventions” and that it would
be impossible to examine the latter without perceiving at once “the
decided superiority of the one invented by Professor Morse.”


Uncle Sam Helped Build the First Telegraph Line.

~FIRST TELEGRAPH LINE FROM BALTIMORE TO WASHINGTON~

At the time Morse’s Recording Telegraph was invented there were, of
course, no telegraph lines in any part of the world, with the exception
of the short lines of wire put up by investigators for experimental
purposes. To remove the obscurity as to the purpose to be served by the
telegraph was the first problem which presented itself to Morse and his
backers. In 1843 an appropriation was secured of $30,000 from the U. S.
Government, with which a line was built from Washington to Baltimore.
This was built and operated by the Government for about two years, but
the Government refused to purchase the patent rights. So the owners
of the patents endeavored to get the general public interested in the
telegraph as a commercial undertaking and gradually companies were
founded and licensed to use the invention.

By 1851 there were as many as fifty different telegraph companies in
operation in different parts of the United States. A few of these
used the devices of a man named Alexander Bain, which were afterwards
adjudged to infringe the Morse patents, and one or two used an
instrument invented by Royal E. House of Vermont, which printed the
messages received in plain Roman letters on a ribbon of paper. This at
first seemed to have an advantage over that of Morse, which received
the message in dots and dashes, in the Morse Code, and these had
to be translated and written out by an operator before they could
be delivered. However, as time went on, the operators came to read
the Morse messages by the sound of the dots and dashes, instead of
waiting to read the paper tape having the dots and dashes marked on
it, and finally the recording feature was given up and the sounder, or
instrument which simply clicks out the message, came into general use.

In the early days, the possibility of the business were little
understood and many telegraph companies failed. April 8, 1851,
papers were filed in Albany for the incorporation of the New York
and Mississippi Valley Printing Telegraph Co. This company, which
soon afterwards changed its name to Western Union, was destined to
absorb the various companies throughout the country until it, in time,
operated the telegraph lines over practically the entire United States,
and has its blue sign in nearly every town and hamlet in the country.

[Illustration: AN EXPENSIVE EQUIPMENT NECESSARY TO-DAY

OPERATING ROOM.

In large cities like New York and Chicago, the operating rooms are very
large. For instance, the main operating department of the Western Union
Telegraph Co. in New York City has 1000 operators. This picture shows
an operating room. The men and women sit in opposite sides of long
tables. On the tables are the keys and sounders by which they send and
receive the messages. Each operator has a typewriter, or “mill,” as he
calls it, on which he writes off the message as it comes to him over
the wire.]

[Illustration: MAIN SWITCHBOARD.

The picture shows a main switchboard in a large operating room. To this
come the ends of the wires from other cities, and to it are connected
the wires from the instruments in front of the operators. By putting
plugs, attached to each end of a wire, into the sockets in the board,
any wire can be connected with any operating position, or several local
circuits can be connected up with a main line from the outside.]

[Illustration: A THOROUGH SYSTEM MUST HANDLE THE MESSAGES

A SECTION OF THE REPEATER ROOM.

When a wire runs to a distant point from the main operating department
of the telegraph company in a large city, the same electric current
which runs through the key of the operator as he sits at his place,
busily sending messages, does not go out over the wire to that distant
point. It simply goes to the repeater room and operates a repeater,
which sends out another current over the long wire which leads to the
destination of the message. This is necessary because the condition
of the weather affects the lines and the current strength has to be
changed to suit the changing line conditions. The operators haven’t
time to make these adjustments, and so all the repeaters are grouped
together in the repeater room where they are under the watchful eyes
of experts. Here also are the delicate instruments which separate the
messages coming over duplex and quadruplex wires, by responding to
impulses of various strengths. These messages which have been separated
are then transmitted by the duplex or quadruplex repeaters to different
operators in the operating room, who hear their sounders tick out the
message just the same as if it came over a simple Morse wire.]

[Illustration: CABLES ENTERING A CENTRAL OFFICE.

You may not but your father will remember the time when in large cities
there were tall telegraph poles with hundreds of wires on them running
along the main streets, so that the town seemed to be bound with great
spiders’ web. That is all changed now, and the telegraph wires are run
through ducts, placed underground. For this purpose they are made up
in cables, and in the picture you see a number of cables entering a
central office.]

[Illustration: THE MARVEL OF TELEGRAPH INSTRUMENTS

WHEATSTONE SENDING INSTRUMENT.

These two photographs show the most modern form of the instruments
which, as we are told on another page, were invented in England by
Wheatstone and Cooke. In sending a paper tape is punched in what
is called a perforator, which has a keyboard like a typewriter. A
certain combination of holes means a certain letter. This tape is then
automatically fed through the sending instrument, which sends impulses
over the wire. The tape with the holes punched through it can be seen
in the picture.

On the right is the Wheatstone receiving instrument. It prints the
signals received in dots and dashes on a tape, which is translated by
the operator who typewrites the translation on a message blank for
delivery.]

[Illustration: The automatic telegraph typewriter shown here is one of
the wonderful instruments mentioned on one of the preceding pages. The
operator at the other end of the line writes on a typewriter keyboard,
on the sending instrument. The electric impulses are received by the
machine shown above, which automatically typewrites the message on a
blank, ready for delivery.]

On this page we see some of the first telegraph instruments, in
fact, the very instruments which Professor Morse used in the early
demonstrations of his invention. These instruments may be seen in the
Smithsonian Institution at Washington, D. C. The key is known as the
Vail key, because it is supposed to have been constructed by Alfred
Vail, who worked with Morse in his experiments with the telegraph. As
can be seen it is very simple. One wire was connected to the spring
piece and the other to the post beneath it. When the key was pressed
down, the contact was made and an impulse sent over the wire, either a
dot, if the key was pressed down and immediately released, or a dash if
it were held down for just the fraction of a second before releasing.

From the very first it was found that relays were necessary, because
the current after coming a long way over the wire often was not
strong enough to operate the recording instrument. Therefore, this
weak current was made to go though the electro-magnets of the relay,
magnetizing these and pulling to the left the upright arm which can be
seen in the photograph with a little block of iron attached to it. This
arm, when pulled by the magnets, made a contact at the top and allowed
a strong current from a battery to flow through the magnets of the
recording instrument.

The first practical recording telegraph instrument devised by Morse
is shown. It looks like a clumsy affair compared to the instruments
of to-day, but it worked so effectively as to convince people of the
possibilities of the great invention. In the wooden box, attached to
the frame at the right, is clockwork which pulled a paper tape at an
even rate of speed over a pulley just beneath a needle point. This
needle point is attached to a light framework having a piece of iron
fastened in it. Below this iron are the electro-magnets, and when they
received an impulse of current from the battery, through the relay,
they pulled down the frame so that the point made a mark upon the paper
tape which moved under it. Thus in the tape appeared a series of dots
and dashes, which the operator, knowing the Morse Code, could easily
translate into English.

[Illustration: THE FIRST TELEGRAPH INSTRUMENTS

ONE OF THE FIRST KEYS FOR SENDING TELEGRAMS.]

[Illustration: ONE OF THE FIRST RELAYS.]

[Illustration: The first recording apparatus. The box on the right
contains clock work for pulling a paper tape beneath a sharp point
actuated by magnets.]

[Illustration: THE LITTLE INSTRUMENTS THAT CHECK OFF THE WORDS

A LATER KEY.]

[Illustration: A LATER AND IMPROVED RECORDING INSTRUMENT.

Here we see some early telegraph instruments which have been improved
somewhat from the crude devices illustrated on the preceding page.
The key answers the same purpose as before, but has been improved by
pivoting the lever arm, and having a coil spring, adjustable by means
of a screw, so that the weight necessary to press it down can be varied
to suit the likings of the operator who uses it. The play of the key
or the distance it must be pressed down before it makes an electric
contact, can be adjusted by another screw.

The recording instrument here shown is a much neater affair than the
cumbersome device which Professor Morse first built. The cumbersome
wooden box has been replaced with a neat brass frame containing the
clockwork for drawing the paper tape beneath the marking point, which
is attached to a piece of iron, or armature, placed just above the
magnet.

Below we see the most modern types of Morse instruments. In the center
is the key, which is not much changed except that it is built to be
low down to a table, so that the operator may rest his forearm on the
table top in front of it, and operate the key with his wrist, with less
fatigue. The relay at the left is interesting. It shows how little this
instrument has changed, except for refinement in its appearance, from
the first relay built by Professor Morse. At the right is the Morse
sounder, which has replaced the old Morse tape recording instrument.
When current goes through the magnets they attract a piece of iron
attached to the metal arm and pull it down to strike the brass frame.
This makes a click, and when the current is intercepted, the magnets
release the arm and a spring pulls it back, making another click. The
operator reads the message by listening to the clicks. If the up click
comes right after the down click it represents a dot. If there is a
pause between them, a dash is represented.]

[Illustration:

  Relay

  Key

  Sounder

MODERN MORSE INSTRUMENTS]

[Illustration: WHAT OCEAN CABLES LOOK LIKE WHEN CUT IN TWO

  _Light Intermediate_

  _Heavy Intermediate_

  _Main Cable_

  _Rock Cable_

  _Heavy Shore End_

  _Rock Cable_

  _Heavy Shore End_

  _Heavy Intermediate_

  _Light Intermediate_

  _Deep Sea_

  _Bay Cable_

FIG. 1.--CABLES ON VANCOUVER-FANNING ISLAND SECTION.

Full size.

Core, 600/340.]

[Illustration:

  Yarn Serving & Compound

  16 No. 13 (·095) Galvanized Wires

  Jute Serving

  Gutta Percha

  Copper Conductor

FIG. 2.--CABLES USED ON FIJI-NORFOLK ISLAND-QUEENSLAND AND NEW ZEALAND
SECTIONS. Full size. Core 130/130.

This picture shows cross-sections of a cable which runs from Vancouver,
B. C., to Australia and New Zealand. A cable is not laid with a
uniform cross-section. On the floor of the ocean, perhaps miles below
the surface, the cable rests quietly and is not moved by storms
which generate great waves on the surface of the water. As the cable
approaches the shore, the movement of the water goes deeper and the
cable must be made heavier to prevent it from being worn by movement on
the bed of the ocean. Where the cable passes over a rocky bottom, it is
made much larger in diameter and is heavily armored.]

[Illustration: Here is the cable steamship “Colonia” laying the shore
end of a cable. Note the row of floats upon the water which carry the
cable until the end in the cable office is firmly fastened. When this
is accomplished the floats are removed and the cable sinks to the
bottom.]




The Story in an Ocean Cable


What is a Cable Made of?

A submarine telegraph cable as usually made consists of a core in the
center of which is a strand of copper wire which varies in weight from
seventy to four hundred pounds to the mile. Strands of copper wire
instead of one thick wire of copper are used, because the former is
more flexible. The copper conductor is covered with several coatings of
rubber of equal weight to the copper wires. After this comes a coating
of jute serving, then a layer of galvanized iron wires and finally a
layer of yarn and compound which forms the outer covering of the cable.
In addition to this where the cable lays among rocks that might injure
it, chains are securely wrapped around it, so as to prevent wear and
tear as much as possible.

You may not have known it, but the cable which lies on the bottom
where the water is deepest is never so large as nearer the shore or
in shallow water. Little by little the men who lay and look after
cables have found that it is best to have a specially constructed outer
covering for different depths and character of bottoms so as to provide
the least possible danger of damage through the action of the water on
the bottom.


How is a Cable Laid?

When the cable of sufficient length is completed, it is carried to
a specially equipped vessel which has a great tank for holding the
cable and the necessary machinery for lowering it over the end of the
ship into the water. The cable is carefully coiled in the tank, the
different coils being prevented from adhering by a coat of whitewash.
First then, a sufficient length of cable is paid out to reach the cable
house or shore. Here it is finally tested to see that the entire length
of cable is in working order. If satisfactorily tested, the vessel
steams slowly away on the course outlined, paying out the cable as she
goes.

[Illustration: STORING A CABLE LONG ENOUGH TO CROSS THE OCEAN

Here we see a cable coiled round and round in the tank which holds it
on board the cable ship.]

[Illustration: In the front of the picture we see the cable coming from
the tank in which it is coiled. It goes over the drum of the paying-out
machine and thence to the bow of the ship, where it passes over big
sheaves or pulleys and down into the ocean.]

[Illustration: THE MACHINERY ON A CABLE SHIP

The paying-out machine. The cable makes a couple of turns around the
big drum, which is connected to the dial, so that the dial indicates
the length of cable which has been paid out into the sea.]

[Illustration: The upper forward deck of the cable steamship
“Telconia,” showing the gear which is used in paying out the cable.
Away in the bow are the big sheaves over which the cable goes into the
sea. Nearer is a dynamometer which measures the tension on the cable.]

[Illustration: HOW THE CABLE IS DROPPED INTO THE OCEAN

Here we see the cable on the lead, as it is called, passing over the
big bow sheave from which it dives into the depths of the sea.]

The vessel must pay out more than a mile of cable for every mile she
travels because there must be enough slack allowed at the same time
to provide for the unevenness of the bottom of the sea. For this
purpose the amount of cable paid out must be measured. This is done
by the paying-out machine, which is shown in one of the pictures.
The difference between the speed of the ship and the amount of cable
paid out gives the amount of slack. Too much slack would also be bad,
so that it is a very pretty problem to pay out just enough and both
the speed of the vessel and the rate of paying out the cable must be
watched carefully.

One of the greatest wonders accomplished by the ingenuity of man is the
ocean telegraph, by which we flash messages back and forth under the
sea between the continents and completely around the world.

Hardly had the telegraph become an established fact, before Professor
Morse, who made the telegraph practical, expressed the belief that a
telegraph line to Europe by means of a wire laid on the bottom of the
ocean was easily possible at some future time. Mr. Cyrus W. Field, the
first to lay an ocean cable successfully, heard him and in his own
mind said “Why not now?” The idea fixed itself so thoroughly in his
resolute mind that he soon said to himself “It shall be done,” and
went to work, and labored incessantly through twelve years of failure
and discouragement before he accomplished his task, which was a great
compliment to this giant of American stick-to-it-iveness.

While many doubted the feasibility of the project and others thought
it the dream of a disordered brain, Mr. Field found many who believed
in him and his idea and who loaned him their financial support for the
undertaking.

[Illustration: THE CABLE ARRIVES ON THE OTHER SIDE

Landing the shore end of a cable. The cable is supported on several
boats and this picture shows the inshore boat with the end of the cable
reaching the beach with the seas breaking over her.]

[Illustration: THE MEN WHO MADE THE OCEAN CABLE POSSIBLE

THE PIONEERS OF THE FIRST OCEAN CABLE.]

American genius had not at that time asserted its supremacy in
mechanics and so the first cable had to be made in England; so Mr.
Field ordered one long enough to stretch from the west coast of Ireland
to the eastern point of Newfoundland. English capitalists subscribed
the money and the United States provided the vessel in which to store
and from which to drop the cable into the ocean.

Upon the first attempt to lay the cable, every thing went along nicely
for six days, and then suddenly the cable broke when three hundred and
thirty-five miles had been laid, and many said it could not be done.
Mr. Field, however, full of American pluck and determination, said “We
will try again.” A second attempt was made with two ships, the U. S. S.
“Niagara” and H. M. S. S. “Agamemnon.” Each ship carried half the cable
and they traveled in company to the middle of the ocean. There the two
pieces of the cable were spliced together and the ships started for the
shores in opposite directions. Again, however, when only a little of
the cable had been paid out--a little more than one hundred miles in
fact--the cable broke and both ships were forced to return to England.

In his third attempt the cable was finally laid clear across the
ocean and fastened at both ends. When tried it was found to work
successfully and Queen Victoria and President Buchanan were able to
exchange greetings upon the achievement of a wonderful work. The people
celebrated the event on both sides of the ocean, but in the midst of
the festivities, while a message was being flashed, something happened
to the cable--what, we have never been able to learn--and the cable was
silent, forever.

Nothing daunted, however, Mr. Field by his great courage induced his
backers to buy him another cable and the “Great Eastern” sailed upon
what was to be a most successful mission. Starting from the American
side with the greatest steamship then known in charge of the previous
cable, the other end was successfully landed at Hearts Content,
Ireland, on July 27, 1866, in perfect working order, and the question
of the ocean telegraph was solved.

[Illustration: HOW CABLES ARE REPAIRED

Here is a buoy which is anchored to the cable. The cable ship will pick
it up and haul up the cable to the surface for inspection and perhaps
it will have to be repaired.]

[Illustration: Three grapnels used for picking up a cable from the
bed of the ocean. On the left is a common grapnel. In the middle is a
special grapnel known as Trott-Kingsford. On the right is the ordinary
cutting grapnel. Note the knives on the shaft and the insides of the
prongs.]

[Illustration: In this picture we see a portion of a cable which has
been fouled by the anchor of a ship and badly damaged. Note how the
wires are bunched. The cable splicers will go to work on this and put
in a new piece of cable, after which it will be let down into the sea
again.]

[Illustration: The Western Union Cable ship “Minia,” fast in an ice
field.]

[Illustration: POWERFUL ENGINES NEEDED ON CABLE REPAIR SHIPS

Here are the powerful engines which are used for picking up a cable
which has to be raised from the bottom of the sea for inspection or
repair.]

[Illustration: In this picture we see men at work splicing a cable
which has been picked up out of the depths of the sea and found to be
damaged.]

[Illustration: THE SHIP WHICH HELPED IN LAYING THE FIRST CABLE

  ARMORING MACHINE

Here is one of the machines used for armoring the cable. By armoring
is meant winding steel wires around and around the cable to protect it
from being cut by sharp rocks on the bottom or by deep sea animals like
the teredo, which might attack it.]

[Illustration: The “Great Eastern” which was the first ship to carry a
cable across the Atlantic Ocean.]

[Illustration: This is a section of a telephone cable, known as a
“bulge.” It contains inductance coils to offset what is called the
condenser capacity of the cable, which would otherwise cause the
talking to become blurred.]

[Illustration: THE DOTS AND DASHES WHICH FLASH ACROSS THE SEA

CONTINENTAL MORSE CODE SIGNALS USED IN CABLE WORKING]

Making repairs to a cable where it comes out of the sea on to a bold
rocky shore. Note how the cable is wound with chain to protect it from
the rocks.

[Illustration: Facsimile of Continental Morse Alphabet as Signalled
Across the Atlantic and Copied on Tape by Siphon Recorder Instrument
at the Receiving Station. Signals Enlarged for Purposes of this
Illustration.

Same Signals as They Appear in Actual Working

Here are two photographs showing the continental Morse code signals
used in cable working and the signals as they are received by the
siphon recording instrument at the receiving station. This siphon
recorder is in practical use in the cable world. The dots and dashes
sent into the wire on one side of the ocean according to the Morse
code, cause the siphon recorder through the means of electrified ink to
make a waving line on a tape. The signals are readily reducible again
if necessary to the dots and dashes of the Morse code because dots make
deflections to one side of the center of the tape and dashes to the
other. The operator who receives the message can therefore readily read
it.

  ALPHABET:

  A · --
  B -- · · ·
  C -- · -- ·
  D -- · ·
  E ·
  F · · -- ·
  G -- -- ·
  H · · · ·
  I · ·
  J · -- -- --
  K -- · --
  L · -- · ·
  M -- --
  N -- ·
  O -- -- --
  P · -- -- ·
  Q -- -- · --
  R · -- ·
  S · · ·
  T --
  U · · --
  V · · · --
  W · -- --
  X -- · · --
  Y -- · -- --
  Z -- -- · ·

  FIGURES:

  1 · -- -- -- --
  2 · · -- -- --
  3 · · · -- --
  4 · · · · --
  5 · · · · ·
  6 -- · · · ·
  7 -- -- · · ·
  8 -- -- -- · ·
  9 -- -- -- -- ·
  0 -- -- -- -- --
  OR --]

[Illustration: TO-DAY THERE ARE MANY CABLES ON THE BOTTOM

MAP No. 1

  WESTERN UNION
  TRANS-ATLANTIC CABLES
  AND CONNECTIONS]




THE STORY IN A RAILWAY LOCOMOTIVE


[Illustration: One of the Most Powerful Locomotives in the World]

[Illustration: BOILER OF ARTICULATE COMPOUND LOCOMOTIVE.

The wonder of our railroad systems to-day is the growth of the
locomotive. The necessity for economy in hauling long freight trains
has led to the development of this type of engine. Some idea of its
size can be had from the second picture, which shows the boiler and
firebox of the locomotive shown in the first picture. The firebox is so
large that an ordinary narrow-gauge locomotive of the old style can be
comfortably stored in it.

  LOADED WEIGHTS

  On driving wheels        475,000 lbs.
  On truck wheels           30,000 lbs.
  On trailing wheels        35,000 lbs.
  Total of engine          540,000 lbs.
  Total of tender          212,000 lbs.

  WHEEL BASE

  Driving, rigid                15 ft. 6    ins.
  Total of engine               57 ft. 4    ins.
  Total of engine and tender    91 ft. 5³⁄₁₆ ins.

  CYLINDERS

  Diameter           H.P. 28 ins., L. P. 44 ins.
  Stroke of piston                       32 ins.

  WHEELS

  Diameter of driving wheels, outside    56 ins.
  Diameter of truck wheels               30 ins.
  Diameter of trailing wheels            30 ins.
  Diameter of tender wheels              33 ins.]

[Illustration: CYLINDERS BIG ENOUGH FOR MEN TO SIT DOWN IN

LOW PRESSURE CYLINDERS OF ARTICULATED COMPOUND LOCOMOTIVE.

In the picture we see the cylinders of the locomotive shown on the
previous page. Some idea of their size can be had from the fact that a
good-sized man can sit comfortably in each of them.

  BOILER

  Type                              Ex. Wagon Top
  Working pres. per sq. in.              200 lbs.
  Outside diam. at front end             100 ins.
  Outside diam. at back end              112 ins.
  Length firebox inside              173¹⁄₁₆ ins.
  Length firebox, actual, inside         132 ins.
  Width of firebox inside             108¹⁄₄ ins.
  No. and diam. of tubes           334, 2¹⁄₄ ins.
  No. and diam. of flues            48, 5¹⁄₂ ins.
  Length of tubes                   24 ft. 0 ins.
  Combust. chamber length             39¹⁄₁₆ ins.
  Grate area                         99.2 sq. ft.

  HEATING SURFACE

  Tubes and flues                   6462 sq. ft.
  Water tubes                         67 sq. ft.
  Firebox                            380 sq. ft.
  Total                             6909 sq. ft.
  Superheating surface              1311 sq. ft.

  CLEARANCE LIMITATIONS

  Extreme height               16 ft. 5¹⁄₈ ins.
  Extreme width                11 ft. 8¹⁄₂ ins.
  Length over all              99 ft. 9⁵⁄₈ ins.

  MAXIMUM TRACTIVE POWER

  Working compound                       115,000 lbs.
  Working simple                         138,000 lbs.
  Factor of adhesion (working compound)          4.13
  Factor of adhesion (working simple)            3.44

  TENDER CAPACITY

  Water              12,000 gals.
  Fuel                    16 tons]

[Illustration: THE LOCOMOTIVE ENGINEER’S WORKROOM

Here is a picture of one end of the boiler of this giant locomotive.
It would take a man more than seven feet high to bump his head in the
middle of it while standing on his feet.]

[Illustration: This shows a picture of the engineer’s cab of one of
these great railroad machines. We are accustomed to see the levers
and other machinery for operating the engine right in the back of the
engine cab. Over or near the firebox. Upon looking closely we find
that the operating machinery is at the side of the locomotive and
far forward in the cab. In fact there is a complete set of operating
machinery on both sides of the cab, so that the engineer can run the
engine from whatever side he happens to be on. This is very necessary,
particularly in switching. Near the end of the cab where the engineer
used to sit you will notice a peculiar pipe-like arrangement. This
is not for operating the engine, but is the automatic stoker, which
is fully explained in the next picture. An engine of this size will
require seven tons of coal per hour.]

[Illustration: A MACHINE WHICH DOES THE WORK OF FOUR FIREMEN

When these large locomotives were first used it was found that no one
fireman could shovel in enough coal to keep the steam up. It would
require three or four firemen working constantly to shovel enough coal
to keep this engine going. Man’s inventive genius came to the front,
however, and now we have an automatic fireman, so to speak. Instead of
shoveling coal on one of these engines the fireman merely operates a
lever. This is a picture of the Sweet locomotive stoker installed in
a railroad engine. This machine automatically conveys coal from the
tender to the locomotive, raises it by an elevator to a point above the
fire door, dumps it into the firebox and spreads it evenly over the
grate.]

[Illustration: This is the new type of electric locomotive being used
by the New York Central system]

[Illustration: HOW A FAST TRAIN TAKES WATER WITHOUT STOPPING

The fast express trains haven’t time to stop and take water from the
tank at the side of the railroad as in former days. This picture shows
a tank built between the tracks which enables the engineer to fill
his boilers without slackening speed. When approaching this tank the
engineer simply lowers a tube into the water, the end of which is a
scoop. The moving engine thus forces the water up into the tube, from
which it runs into the boiler.]

[Illustration: This is an improved signal tower from which switches are
operated. If you were ever in a signal tower you will not recognize
this as one, for you are used to seeing a room full of levers which the
tower man had to pull hard when he wished to throw a switch. By the old
way the end of the lever was attached to a wire which was connected
with the switch. The wire running through pipes, when the operator
pulled the lever the switch was pulled shut by the pull on the wire. In
this new plan the switch is controlled by electricity, and the operator
has merely to pull out a plug as shown in the picture, which is much
easier than operating a lever.]

[Illustration: WHAT MAKES A WIRELESS MESSAGE GO

Sketch showing arrangement of aerial on ship equipped with the Marconi
Direction Finder, an instrument which tells the sea captain the exact
points of the compass from which wireless distress signals are being
sent and enables ships to avoid collisions in fog.]




The Story in the Wireless


What is the Principle of the Wireless Telegraphy?

Drop a stone in a pool of water. Circular waves or ripples will travel
outward in all directions. That is the principle of wireless telegraph.

If a chip be floating on the water it will be rocked by each ripple,
just as a wireless receiving station will respond to the electrical
waves or impulses that make up a wireless message. It is not known
just how the invisible wireless waves are propelled through space,
but they travel through the ether in the air in very much the same
way as do sound waves. The electrical signals, too, are received only
by apparatus that is attuned to them; that is, they can not be heard
except at wireless stations, any more than sound can be heard by the
ears of a deaf person.

The wireless waves have a definite length, can be measured in feet or
meters, and are regulated according to the distance the message is to
travel. Stations that send a few hundred miles use a wave length of six
hundred meters, or less, while at the powerful land stations used for
trans-atlantic work the wave lengths used run into as many thousands.


Why Don’t the Messages Go to the Wrong Stations?

So that the hundreds of messages hurtling through space at the same
time will not interfere, the wireless stations are equipped with
tuning-apparatus through which they can adjust their wave length to
receive the particular message desired. A different wave length is
used by each ship or wireless shore station, and even though dozens of
messages fill the air, the minute the wireless operator adjusts his
tuner to the length of the station he is after, that particular message
stands out very strongly and all the others grow dim.

[Illustration: The Marconi Wireless station at Miami, Fla., which is
typical of the shore stations that handle messages to several thousand
ships at sea.]


How Does the Wireless Reach Ships at Sea?

All ships at sea report their positions regularly; thus it is a simple
matter for a shore station to send a wireless message to the ship to
which it is addressed. For example, the Marconi station at Sea Gate,
New York, wants to reach the Lusitania. The operator looks up that
vessel on the list and notes her call signal and wave length. He
adjusts his tuner to correspond and calls her signal, M F A, repeating
it three times.

The wireless man on the vessel, knowing that he is within range of a
shore station, has set his tuner at the wave length assigned to him and
is listening. When his call letters are heard, he acknowledges them
and signals to go ahead with the message. When it has been given, the
Sea Gate station “signs off” with its call letters W S E and the ship
operator enters in his record that that particular message reached him
via the Marconi station at Sea Gate. Thus, with the wide variety in
wave lengths, no confusion of messages exists and any desired ship or
shore station can be called, just as a direct telephone connection is
secured by giving the central station the call number of the subscriber
wanted.


What Kind of Signs Are Used in the Wireless?

The actual wireless message is composed of dots and dashes, which, in
certain combinations, stand for certain letters of the alphabet. This
is done through opening and closing the electrical circuit by pressing
a key, a sharp touch forming a dot and a longer pressure a dash, as
with the wire telegraph.

If secrecy in a wireless message is wanted, the words are sent in
cipher which, of course, cannot be understood by outsiders. The
Government sends thousands of words each day without a single word
meaning anything to the wireless stations that happen to be “listening
in.” While it is true that any one owning a wireless receiving set may
listen to messages flying through the air, every person within hearing
who understands the Morse Code can read the telegrams that come into a
telegraph office. Knowledge thus gained, however, is of little value,
as the law provided heavy penalties for disclosing the contents of any
kind of telegraph message.


What Does a Wireless Equipment Consist of?

The various apparatus that comprises a wireless equipment can not be
properly explained without the use of technical language, but the
general principle of operation is somewhat as follows: If a small loop
of copper wire, with a slight separation between the ends, is placed
across a room from an electric spark, it will be slightly affected.
Increase the electrical current to far greater power and control it,
and the invisible electrical wave may be thrown many miles. To send
a message across the ocean, the current used by the modern wireless
station is so powerful that it will pass through storm and fog,
even through mountains, without losing much of its force. When this
tremendous force is released by pressing the telegraph key, it leaps
from the aerial wires, or antennae, travels across the Atlantic and is
picked up by a corresponding aerial, attuned to receive the signal.

[Illustration: Pack and riding horses grouped together ready for
unloading the Marconi wireless set used in the cavalry.

Station set up and working.

WORKING THE WIRELESS IN THE ARMY.]

The aerial, or antennae, as it is called in a wireless work, is made up
of copper wires. On a ship these are strung between the masts, usually
consisting of two, four or six wires held apart by crosspieces. Two or
more wires lead down from this to the wireless cabin.

The coil or transformer is the apparatus which produces the spark that
forms the electrical waves. In small stations, the length and thickness
of the spark and the speed of vibration is regulated by a thumb screw.
Transformers are used when the power is taken from the alternating
current of an electric light circuit.

The gap, which the electrical current jumps when the telegraph key is
pressed down, is composed of two rods which slide together or apart to
vary the length of the spark.

The simplest type of sending station consists of the antenna, battery,
coil, wireless key and spark gap. If a change in wave length is desired
a transmitting tuning coil must be added.

The receiving apparatus contains a detector, which is chiefly two
mineral points lightly touching and connected with a sensitive head
telephone. The incoming signals are heard as long and short buzzing
sounds corresponding to the dots and dashes. The receiving tuning coil,
used to adjust wave lengths, is operated by simply moving sliding
contacts along a bar until the signals are more plainly heard. While
the large stations have more complicated apparatus, the principle
remains the same.

[Illustration: The masts for the cavalry wireless sets are so attached
that they can be loaded and unloaded with the utmost rapidity; a
complete station can be erected or dismantled in less than ten minutes.]

[Illustration: The gasoline engine which supplies the power for
operating a cavalry wireless station is fitted to the saddle frame and
is light enough to be carried by one horse.

THE WIRELESS IN THE ARMY]


How High Do Wireless Masts Have to be?

The towering masts of the Marconi Trans-Oceanic stations are often
supposed to rise to their great height, so that an antennae will be
raised above the obstructions between. If this were necessary, two
wireless stations separated by the Atlantic would have to have masts
one hundred and twenty-five miles high to rise above the curvature
of the earth. The path of the wireless waves, however, is not in a
straight line, but follows the curvature of the earth. Scientists
explain this by saying the rarefied air above the earth’s surface acts
as a shell enclosing the globe.

The speed of wireless messages is placed at 186,000 miles per second. A
wireless message will thus cross the Atlantic in about one-nineteenth
of a second--a period of time too small for the human mind to grasp.
In other words, the wireless flash crosses in a fraction of a second a
distance that the earth requires five hours to turn on its axis and the
fastest ships take nearly a week to cross.

The longest distance over which a wireless message can be sent is not
definitely known; the present record was made in September, 1910, by
Marconi from Clifden, Ireland, to Buenos Aires, Argentina, a distance
of 6700 miles.

[Illustration: THE WIRELESS PREVENTS ACCIDENTS AND SAVES MANY LIVES

This photograph makes us appreciate what a wonderful aid is wireless to
navigators. On Easter Sunday, 1914, the U. S. Revenue Cutter “Seneca,”
patrolling the North Atlantic, found these two gigantic icebergs in
the regular steamer lanes and sent out wireless warnings to all nearby
steamships.]

[Illustration: HOW THE WIRELESS IS INSTALLED ON FAST TRAINS

RAILROAD WIRELESS.--ANTENNA ON CARS.]

[Illustration: WIRELESS STATION ON TRAINS.]

[Illustration: WIRELESS STATION IN U. S. ARMY

City side of Scranton station, Lackawanna R.R., showing aerial of
wireless which communicates with trains.]

[Illustration:

  Photo by Stefano

WIRELESS RECEIVING STATION IN U. S. ARMY.]

[Illustration: Guglielmo Marconi, Inventor of wireless telegraphy.]


The Man Who Invented Wireless Telegraphy.

Communication without wires for thousands of miles across oceans, from
continent to continent, is a far cry from sending a wireless impulse
the length of a kitchen table. That is the development of twenty years.

To properly trace the development of wireless telegraphy, however, it
is necessary to go back eighty-three years to when, in 1831, Michael
Faraday discovered electro-magnetic induction between two entirely
separate circuits. Steinheil, of Munich, too, in 1838, suggested
that the metallic portion of a grounded electrical circuit might be
dispensed with and a system of wireless telegraphy established. Then,
in 1859, Bowman Lindsay demonstrated to the British Association his
method of transmitting messages by means of magnetism through and
across the water without submerged wires. In 1867 James Clerk Maxwell
laid down the theory of electro-magnetism and predicted the existence
of the electric waves that are now used in wireless telegraphy.
Dolbear, of Tufts College, in 1836, patented a plan for establishing
wireless communication by means of two insulated elevated plates, but
there is no evidence that the method proposed by him effected the
transmission of signals between stations separated by any distance.
A year later Heinrich Rudolph Hertz discovered the progressive
propagation of electro-magnetic action through space and accomplished
the most valuable work in this period of speculation and experiment.

Just twenty years ago, at his father’s country home in Bologna,
Guglielmo Marconi, then a lad just out of his ’teens, read of the
experiments of Hertz and conceived the first wireless telegraph
apparatus. This was completed some months later and a message in the
Morse Code was transmitted a distance of three or four feet, the length
of the table on which the apparatus rested.

Satisfied that he had laid the foundation of an epoch-making discovery
young Marconi pursued his experiments and filed the first patent on the
subject on June 2, 1896. Further experiments were carried on in London
during that year and at the request of Sir William H. Preece, of the
British Post Office, official tests were made, first over a distance of
about 100 yards and later for one and three-quarter miles.

During the year following Mr. Marconi gave several demonstrations to
the officials of the various European governments and communication
was established up to 34 miles. In July of this year, 1897, the first
commercial wireless telegraph company was incorporated in England and
the first Marconi station was erected at the Needles, Isle of Wight.

On June 3, 1898, Lord Kelvin visited this station and sent the first
paid Marconigram. A month later the events of the Kingstown Regatta in
Dublin were reported by wireless telegraphy for a local newspaper from
the steamer “Flying Huntress.” In August of that year the royal yacht
“Osborn” was equipped with a wireless set, in order that Queen Victoria
might communicate with the Prince of Wales, who was at Ladywood Cottage
and suffering from the results of an accident to his knee. For sixteen
days, constant and uninterrupted communication was maintained. Then on
Christmas Eve was inaugurated the first lightship wireless service,
messages being sent from the East Goodwin lightship to the lighthouse
at South Foreland.

[Illustration: PREPARING TO SEND MESSAGES ACROSS THE OCEAN

This photograph shows how wireless messages are prepared for direct
transmission across the ocean. The dots and dashes of the telegraphic
code are punched on tapes by skilled operators, thus insuring accuracy
and a permanent record of each message. Five or six operators, and
sometimes more, are steadily preparing these tapes, which are pasted
together and run through a machine which operates the key at each
perforation. A speed of 100 words a minute is thus obtained.]

Three months later the first marine rescue was effected through this
installation. The steamship “R. F. Matthews” ran into the lightship
and lifeboats from the South Foreland station promptly responded to
the wireless appeal for aid. The most important wireless event abroad
during the year 1899 was the establishing of communication across the
English Channel, a distance of thirty miles.

The American public next learned something of Marconi’s invention, for
in September and October of that year wireless telegraphy was employed
in reporting the International yacht races between the “Shamrock” and
the “Columbia” for a New York newspaper. At the conclusions of the
races, the naval authorities requested a series of trials, during which
wireless messages were exchanged between the cruiser “New York” and
the battleship “Massachusetts” up to a distance of about 36 miles. On
leaving America, Marconi fitted the liner “St. Paul” with his apparatus
and when 36 miles from the Needles Station, secured wireless reports
of the war in South Africa. These were printed aboard the vessel in a
leaflet called “The Transatlantic Times,” the first of the chain of
wireless newspapers now published daily on practically all passenger
steamships. Six field wireless sets were dispatched to South Africa
about this time and were later of considerable service in the Boer War.

[Illustration: In the foreground of this picture is seen the automatic
transmitter with the message perforated tape running through. This is
one of the smaller wireless equipments; much larger ones are used at
the new Marconi stations.]

The year 1900 brought the first commercial wireless contracts. By
agreement with the Norddeutscher Lloyd, Marconi apparatus was installed
on a lightship, a lighthouse and aboard the liner “Kaiser Wilhelm der
Grosse.” On July 4th the British Admiralty entered into a contract
for the installation of Marconi apparatus on thirty-two warships and
shore stations and the erection of the high power station at Poldhu was
commenced.

~WORLD WIDE USE OF THE WIRELESS~

Work on similar station at Cape Cod was begun early in 1901 and on
August 12th the famous Nantucket Island and Nantucket lightship
stations opened to report incoming vessels by wireless. Heavy gales
in September and November wrecked the masts at both Poldhu and
Cape Cod stations and these were replaced by four wooden towers,
210 feet high. Important experimental work was then shifted to St.
John’s, Newfoundland, and on December 12th and 13th, signals were
received across the Atlantic from Poldhu. This to Marconi was a great
achievement and the forerunner of the present day trans-atlantic
service. But with the announcement that the long dreamt of feat had
been accomplished a flood of vituperation from scientific men was let
loose. It was nonsense; it was deliberate deception; the reading was
in error, were among the comments. Another prank of the “young man
with a box,” one scientist termed it. It is amusing now to recall this
extraordinary treatment, but it was hardly so amusing to the young
inventor, then in his twenty-seventh year.

But in spite of the skepticism, developments followed rapidly from then
on and in 1902, the year in which the American Marconi Company was
established, full recognition to wireless telegraphy was given by the
various governments.

The wonderful growth of the Marconi system within the last twelve years
is well known to all and does not require detailing. But in view of its
youth as an industry and its inauspicious beginning, a glimpse into
what the present day Marconi system comprises may be interesting.

More than 1800 ships are equipped with Marconi wireless and its shore
stations are landmarks in practically every country on the globe.

Press and commercial messages are transmitted daily from continent to
continent direct.

Shore to ship and ship to shore business each year runs into millions
of words.

Marconi wireless within seventeen years, has become an absolute
necessity in the maritime field, an invaluable aid in others. Regular
communication has been established with icebound settlements and desert
communities, and official running orders transmitted to moving railway
trains. Its service is dependable under all conditions and embraces
activities and locations inaccessible to any other telegraph system.
Continuous service is maintained and wireless messages for all parts of
the world at greatly reduced rates are received at any Western Union
Office.

The direction finder and wireless compass are recent Marconi inventions.

A wide variety of types of Marconi equipment are designed for the
merchant marine, warships, submarines, pleasure craft, motor cars
and railroad trains; also portable signal corps sets, apparatus for
aircraft, cavalry sets, knapsack sets and high-power installations for
trans-ocean communication.




How Does a Fly Walk Upside Down?


There is a little sucker on the end of each of the fly’s feet which
makes his foot stick to the ceiling or any other place he walks, and
which he can control at will. It is made very much like the sucker
you have seen with which a boy can pick up a flat stone--a circular
piece of rubber or leather with a string in the middle and more or
less bell shaped underneath. A boy can pick up a flat stone with this
kind of a sucker by pressing the rubber or leather part down flat on
the stone and then pulling gently on it by the string. When he does
this he simply expels the air which is between the leather part of
the sucker and the stone, which creates a vacuum and the pressure of
the air on the outside part of the leather enables him to pick it up.
The fly has little suckers like these on each of his feet, and they
act automatically when he puts his foot down. Of course the sticking
power of each foot is adjusted to the weight of the fly, just as the
sticking or lifting power of the boy’s sucker is regulated by the
weight of the stone or other object he tries to pick up. If the weight
of the object is sufficient to overcome the sticking power which the
vacuum creates, the stone cannot be lifted.




What Is Money?


It is quite difficult to give a broad definition of money that will be
understood by all, for in different ages and lands many things have
been used as money besides the coins and bills which we think of only
when we think at all what money is. Anything that passes freely from
hand to hand in a community in the payment of debts and for goods
purchased, accepted freely by the person who offers it without any
reference to the person who offers it, and which can be in turn used
by the person accepting it to give to some one else in payment of debt
or for the purchase of goods, is money. This is rather a long sentence
and perhaps difficult to understand, and so we will try to analyze
what this means. If some one offered you a pretty stone as money in
payment of a debt, it would be as good as any kind of money if you in
turn could pass it on to any other person to whom you owed a debt or in
payment of something you bought. The stone might appear to you to be
valuable but it would not be good money unless you could count on every
one else in the community accepting it at the same value. If everybody
accepts it at the same value, it is as good as any kind of money. So
that anything which is acceptable to the people in any community as a
unit of value to pay debts, is good money, provided everybody thinks so
and accepts it that way. In this case, then any kind of substance might
become money provided it was used and accepted by everyone.




Why Do We Need Money?


We need money for the sake of the convenience which it provides in
making the exchange of one kind of wealth for another and as a standard
of value. When a community has adopted something or anything which
is regarded by all of the people as a standard of value, all of the
difficulties of trading disappear.




Who Originated Money?


The earliest tribes of savages did not need money because no individual
in the tribe owned anything personally. All the property of the tribe
belonged to the tribe as a whole and not to any particular person.
Later on, when different groups of savages came into contact with each
other, there arose the custom of bartering or exchanging things which
one tribe possessed and which the other tribe wanted. In that way arose
the business of trading or of what we call doing business, and soon the
need of something by which to measure the values of different things
arose. Some of the old Australian tribes had a tough green stone which
was valuable for making hatchets. Members of another tribe would see
some of this stone and notice what good hatchets could be made from
it--better hatchets than they had been able to make. Naturally they
wanted it so much that it became very valuable in their eyes and so
they came wanting to buy green stones. But they had nothing like what
we could call money today. They had, however, a good deal of red ochre
in their lands which they used to paint their bodies. They got this
red ochre out of the ground on their own lands just as the other tribe
got green stones out of its ground, and those who owned the green
stones which were good for making hatchets, wanted some red ochre very
much, and so they traded green stones for red ochre. The green stones
then took on a value in themselves for making exchanges for various
commodities, and before long became a kind of money inside and outside
the community so that when they wanted to obtain anything, the price
was put by the merchant as so many green stones and he accepted these
in payment for goods given in exchange. He was willing to do this
because he knew he could use them in making trades for almost anything
he might want, provided he had enough of the green stones. So you see
these green stones of the Australian tribe became a rudimentary kind of
money, just because a desire had arisen to possess them; and the red
ochre was actual money in the same sense, for when this tribe found
that other tribes would value this red ochre, they began getting the
things they wanted and paying for them in red ochre. But the “unit of
value” had to be developed to make a currency that was elastic. It
required something that could be carried about easily--in fact it had
to be something small enough so a number of units of value could be
carried about without too much trouble. The Indians of British Columbia
solved this difficulty of making an elastic currency by adopting as a
unit of value a haiqua shell which they wore in strings as ornamental
borders of their dresses--and one string of these shells was worth
one beaver’s skin. These shells then were real money and one of the
earliest forms of it.

The skins of animals were long used by savage tribes as money. The
skins were valuable in trading and a man’s fortune was reckoned by the
number of skins he owned. As soon as the animals became domesticated,
however, the whole animal replaced the skin as the unit of value. This
change undoubtedly came because a whole animal is more valuable than
only its skin. The first skins obtainable however were worn by wild
animals--the kind that the people could not deliver to someone else
alive and whole. But when the animals became domesticated, which meant
that man tamed them and kept them where he could control them at will,
the skin and the wild animal ceased to be a unit of value because it
was an uncertain kind of money. Among domestic animals, oxen and sheep
were the earliest forms of money--an ox was considered worth ten sheep.
This idea of using cattle as money was used by many tribes in many
lands. We find traces of it in the laws of Iceland. The Latin word
pecunia (pecus) shows that the earliest Roman money was composed of
cattle. The English word fee indicates this also. The Irish law records
show the same evidence of the use of cattle as money and within recent
years the cattle still form the basis of the currency of the Zulus and
Kaffirs.

When slavery became prominent many lands adopted the slaves as the unit
of value. A man’s wealth was reckoned by the number of slaves he owned.

Then, when the practice of agriculture became more common, people
used the products of the soil as money--maize, olive oil, cocoanuts,
tea and corn--the latter is said to pass current as actual money in
certain parts of Norway now. They used these products of the soil for
money even in our own country. Our ancestors in Maryland and Virginia
before the Revolutionary War, and even after, used tobacco as money.
They passed laws making tobacco money and paid the salaries of the
government officials and collected all taxes in tobacco.

Other early forms of money were ornaments and these serve the purpose
of money among all uncivilized tribes. In India they used cowrie
shells--a small yellowish-white shell with a fine gloss. The Fiji
Islanders used whales’ teeth; some of the South Sea Island tribes used
red feathers; other nations used mineral products as money--such as
salt in Abyssinia and Mexico.

Up to this point we have talked about the things used as money from
the standpoint of primitive forms of money. Today the metals have
practically driven all these other crude forms of money out.




Metallic Forms of Money.


~WHY WE USE METALS FOR COINING~

The use of metals as money goes far back in the history of civilization
but it has never been possible to trace the historical order of the
adoption of the various metals for the purposes. Iron according to the
statement of Aristotle was at one time extensively used as money.
Copper, in conjunction with iron, was used in early times as money in
China; and until comparatively a short time ago was used for the coins
of smaller value in Japan. Iron spikes were used in Central Africa
and nails in Scotland; lead money is now used in Burmah. Copper has
long been used as money. The early coins of England were made of tin.
Finally, however, came silver and silver was the principal form of
money up to a few years ago. It was the basis of Greek coins introduced
at Rome in 269 B. C. Most of the money of Medieval times was composed
of silver.

The earliest traces of gold used as money is seen in pictures of
ancient Egyptians “weighing in scales heaps of gold and silver rings.”




Why Do We Use Gold and Silver as Money Principally?


There are a good many reasons why gold and silver have become almost
universal materials for use as money. Perhaps this will be better
understood if these reasons are set down in order.

1st. It is necessary that the material out of which money is made
should be valuable, but nothing was ever used as money that had not
first become desirable and, therefore, valuable as money. This is only
one of the incidental reasons for taking gold and silver for coining
money.

2nd. To serve its purpose best, money should be easy to carry
around--in other words, its value should be high in proportion to its
weight.

The absence of this quality made the early forms of money such as
skins, corn, tobacco, etc., undesirable. It was difficult to carry very
much money about. Imagine the skin of a sheep worth a dollar, say,
and having to carry ten of them down to pay the grocer. To a certain
extent this difficulty occurred with iron and copper money and in times
when they used live cattle it was a pretty expensive job to pay your
debts because, while the cattle could move, it was still expensive to
drive them from place to place. A man who accepted a thousand cattle
in payment had to go to some expense in getting them home. Then it was
expensive to have money when live cattle were used because the cattle,
of course, had to be fed and from that point of view the poor man who
had no money was better off than the rich man who had money. When
cattle were used as money it cost a lot to keep it. Our kind of money
doesn’t eat anything; in fact, if you put it in a savings bank, it will
earn interest money for you. But when cattle were used as money it cost
a great deal to keep them and so it was worse than not earning any
interest.

3rd. Another quality that money should possess is divisibility without
damage and also the quality of being united again. This quality is
possessed by the metals in every sense because they can be fused, while
skins and precious stones suffer in value greatly when they are divided.

4th. The material out of which money is made should be the same
throughout in quality and weight so that one unit of money should be
worth as much as any other unit. This could never be true of skins or
cattle as the difference in the size of skins is very great sometimes,
and a small skin from the same animal could not be worth as much as a
large one, or a skin of an animal of inferior quality so valuable as a
very fine one.

5th. Another quality which money should possess is durability. This
requirement made it necessary to use something else besides animals or
vegetable substances. Animals die and vegetables will not keep and so
lose their value. Even iron is apt to rust and through that process
lose more or less of its value.

6th. The materials out of which money is made should be easy to
distinguish and their value easy to determine. For this reason such
things as precious stones are not good to use as money because it
takes an expert to determine their value and even they are not always
certain to be correct.

7th. Then a very important quality that the material out of which money
is made is that its value should be steady. The value of cattle varies
very greatly and, in fact, most of the materials out of which the first
currencies were made were subject to quick change in value in a short
time. The value of gold and silver does not change excepting at long
intervals. Gold and silver are both durable and easily recognizable.
They can be melted, divided and united. The same is true of other
metallic substances, but iron as stated is subject to rust and its
value is low; lead is too soft. Tin will break, and both of them and
copper also are of low value. Gold and silver change only slowly in
value when the change at all; they do not lose any of their value by
age, rust or other cause; they are hard metals and do not, therefore,
wear. Their value in proportion to the bulk of the pieces used for
money is so large that the money made from them can be carried without
discomfort and it is almost impossible to imitate them.




Who Made the First Cent?


Vermont was the first state to issue copper cents. In June, 1785, she
granted the authority to Ruben Harmon, Jr., to make money for the state
for two years. In October of the same year, Connecticut granted the
right to coin 10,000 pounds in copper cents, known as the Connecticut
cent of 1785. Massachusetts, in 1786, established a mint and coined
$60,000 in cents and half cents. In the same year, New Jersey granted
the right to coin $10,000 at 15 coppers to the shilling. In 1781 the
Continental Congress directed Robert Morris to investigate the matter
of governmental coinage. He proposed a standard based on the Spanish
dollar, consisting of 100 units, each unit to be called a cent. His
plan was rejected. In 1784, Jefferson proposed to Congress, that the
smallest coin should be of copper, and that 200 of them should pass for
one dollar. The plan was adopted, but in 1786, 100 was substituted. In
1792 the coinage of copper cents, containing 264 grains, and half cents
in proportion, was authorized; their weight was subsequently reduced.
In 1853 the nickel cent was substituted and the half cent discontinued,
and in 1864 the bronze cent was introduced, weighing 48 grains and
consisting of 95 per cent. of copper, and the remainder of tin and zinc.




How Did the Name Uncle Sam Originate?


The name Uncle Sam is a jocular name long in use for the Government of
the United States.

Shortly after the war of 1812 was declared, Elbert Anderson of New
York State, who was a contractor for the army, went to Troy, New York,
to purchase a quantity of provisions. At that place the provisions
were inspected, the official inspectors being two brothers named
Wilson--Ebenezer and Samuel. The latter was very popular among the men
and was known as “Uncle Sam Wilson” and everybody called him that.
The boxes in which the provisions were packed were stamped with four
letters, E. A. for Elbert Anderson, and U. S. for United States. One of
the men engaged in making the inspection asked another of the workmen
who happened to be a jocular fellow, what the letters E. A. U. S. on
the boxes stood for. He said in reply that he did not know but thought
they probably meant Elbert Anderson and Uncle Sam Wilson, and that they
had left off the W which would stand for Wilson. The suggestion caught
on quickly and as such things often do, the joke spread rapidly so that
everybody soon thought of the name “Uncle Sam” whenever they saw the
letters U. S. on anything or in any place.

The suit of striped trousers and long tailed coat and beaver hat
in which Uncle Sam is now always represented in pictures, was the
inspiration of the famous cartoonist.

[Illustration: THE WORLD’S BREAD LOAVES

  Egypt
  2500 B.C.

  Unleavened Bread
  2000 B.C.

  Pompeii
  50 A.D.

  Palestine

  Modern American Loaf

  England

  England

  France

  Hungary

  Spain

  Switzerland

  Bohemia

  Holland

  Italy

  Austria

  Germany

  Balkan States]

[Illustration: HARVESTING WHEAT.]




The Story in a Loaf of Bread


Why is Bread so Important?

The history of bread as a food reads like a romance. It has played an
important part in the destinies of mankind and its struggles through
the ages to perfection. The progress of nations through their different
periods of development can be traced by the quality and quantity of
bread they have used.

No other food has taken such an important part in the civilization of
man.

To a large extent it has been the means of changing his habits from
those of a savage to those of a civilized being. It has supplied the
peaceful pursuits of agriculture and turned him from war and the chase.

It is an interesting fact that the civilized and the semi-civilized
people of the earth can be divided into two classes, based upon their
principal cereal foods: the rice eaters and the bread eaters.

Every one admits that rice eaters are less progressive, while bread
eaters have always been the leaders of civilization.

It is an interesting fact that just as Japan is changing from a
rice-eating nation to a bread-eating nation she is asserting her power.

Any one who stops to consider the history of nations will see that this
matter of what we eat is the one question of vital importance.

Bread is one of the earliest, the most generally used and one of the
most important foods used by man. Without bread the world would not
exist without great hardship. On bread alone a nation of people can
exist, and to sit down to a meal without it causes us to feel at once
that something is missing.


What Was the Origin and Meaning of Bread?

Bread is baked from many substances, although when we think of bread,
we usually think of wheat bread. It is sometimes made from roots,
fruits and the bark of trees, but generally only from grains such as
wheat, rye, corn, etc. The word bread comes from an old word _bray_,
meaning to pound. This came from the method used in preparing the food.
Food which was pounded was said to be brayed and later this spelling
was changed to bread. Properly speaking, however, these brayed or
ground materials are not really bread in our sense of using the term
until they are moistened with water, when it becomes dough. The word
_dough_ is an old one meaning to “moisten.” This dough was in olden
times immediately baked in hot ashes and a hard indigestible lump of
bread was the result. Accidentally it was discovered that if the dough
was left for a time before baking, allowing it to ferment, it would
when mixed with more dough, swell up and become porous. Thus we got our
word loaf from an old word _lifian_, which meant to raise up or to lift
up.


When Was Wheat First Used in Making Bread?

It is not clearly known when or by whom wheat was discovered, but it
seems to have been known from the earliest times. It is mentioned in
the Bible, can be traced to ancient Egypt and there are records showing
that the Chinese cultivated wheat as early as 2700 B.C. To-day it
supplies the principal article for making bread to all the civilized
nations of the world.

The origin of the wheat plant is said to have been a kind of grass
which is given a Latin name _Ægilops ovata_ by the botanists.


Will Wheat Grow Wild?

This is a question that has puzzled the world’s scientists for more
than two thousand years. From time to time it has been reported by
investigators in various parts of the world that here and there wheat
has been found growing wild and doing well, but every time a further
investigation is made, it develops that the wheat has been cultivated
by some one. There is as yet no evidence for believing that wheat will
grow in a wild state.


What is the Difference between Graham Flour and Whole Wheat?

Graham flour from which Graham bread is baked is made from unbolted
flour. The process of bolting flour, which is described in one of the
following pages, consists briefly in taking out of it all but the
inside of the grain of wheat. When this has been done, we have pure
white flour.

In making Graham flour every part of the grain of wheat is left in the
flour, and ground up finely. Many people think that Graham flour is
made from a special grain called Graham, but this is not true. It is
said that Graham bread is not so good for you because it contains the
outside covering of the wheat grain or bran which is composed of almost
pure silica, the same substance of which glass is made, and cannot
therefore be good for us.

Whole wheat flour is made from the whole grain of wheat from which the
outside covering or bran has been separated. It contains everything but
the bran and is therefore the most nutritious flour made.

The grain of wheat has several coverings of bran coats, the outer one
of which is the one composed of silica, and which is not valuable
as food. Underneath this husk--are found the inner bran coats,
which contain the gluten. Gluten is a dark substance containing the
flesh-forming or nitrogenous elements, which are valuable in muscle
building. The inside or heart of the grain of wheat consists of cells
filled with starch, a fine white mealy powder which has little value
as food, but is a great heat producer. Sometimes in making whole wheat
flour, the heart of the grain is also removed, making a pure gluten
flour. The name whole wheat for flour is not accurate, therefore, for
Graham flour is made of the whole wheat grain, while “whole wheat”
flour is made of only certain parts of the grain of wheat.

[Illustration: Wheat conditioners for tempering the wheat before being
ground by the corrugated roller mills.]


How is Flour Made?

In great factories the raw material is frequently taken in at one end
and comes out of the opposite end as a finished locomotive, a Pullman
palace car, or a pair of shoes. There is no such progression in making
flour. The wheat comes in at one place as a plain Spring or Winter
wheat and at another goes out as flour, but in the process parts of
it may go from top to bottom of the big mill 30 times. Instead of a
factory where everything moves along from hand to hand or machine to
machine, the flour mill is like a human body--a huge framework like the
bones, with thousands of carrying devices, “elevators,” “spouts” and
“conveyors,” like the veins and arteries of the blood-carrying system.
Stop up a vein of wheat, the mill becomes clogged, and finally must
shut down if it cannot be mechanically relieved. It is an intricate and
intensely interesting process, the result of year-to-year experience.

[Illustration: SEPARATING THE WHEAT FIBER AND GERMS

Purifier for separating the fiber, germ, and other impurities from the
semolina (grits) before it is finally crushed or ground into flour by
smooth roller mills.]


Scouring that Suggests a Dutch Kitchen.

From the storage bins the wheat is drawn off through conveyors to the
first of several cleaning processes, the “separators,” where the coarse
grain which naturally comes with the wheat, such as corn and oats, and
imperfect kernels of wheat, is taken out. After this general cleaning
the grain goes to the “scouring machine,” which is an interesting
device--a rapidly revolving cylinder with what are called “beaters”
attached. The grain is thrown against perforated iron screens. Any
clinging dirt is loosened, and a strong current of air passing through
the cylinder is constantly “calling for dust,” as the miller aptly
expresses it, and carries the impurities away as dust and dirt. Indeed,
the cleaning process seems to be a constant one from the time the
wheat enters the mill until the flour is made. Having been cleansed,
the wheat is now ready for the rolls except for a “tempering” process,
which is to prepare the grain, so that the outside of the wheat may be
taken off without injury to the inside or kernel.

Then as the grain passes to the rolls there begins a gradual reduction
of wheat to flour which is most intricate.

The first sets of rolls are corrugated and so adjusted as to “break”
each grain of wheat into 12 to 15 parts. The “breaking” process goes on
through five different sets of rolls.

[Illustration: GRINDING THE WHEAT FOR MAKING FLOUR

Corrugated roller mills for grinding the wheat after it has been
cleaned.]

[Illustration: Wooden spouts for conveying the different products, bran
and partly ground wheat, from one machine to another.]

[Illustration: THE FLOUR IS READY FOR BAKING

Gyrating sifter for separating the bran particles from the flour and
semolina.]


The Big Bolters with Silken Sieves.

Closely allied with the rolling process is the bolting process,
which, working hand in hand with it has made modern flour making so
perfect. The bolting process consists of a series of sieves--a sifting
of the broken grain so that it is finally, after repeated breaking
and sifting, a flour. The bolter machine contains a number of sieves
covered with silk bolting cloth with varying mesh or number of threads
to the square inch. This bolting machine, moving rapidly, makes from
8 to 10 different separations of the material. From rolls to bolters,
from bolters to purifiers, from purifiers to rolls, over and over, the
process continues, until five different grades of “middlings” have
been selected by the mechanical hands of the millers. The purifier is
still another step to the process. It is a machine having eight sieves
of different mesh. The “middlings” flow down over the different sieves
in a thin sheet, a current of air meantime drawing all impurities out.
With this purifying process completed, the material is ready for the
smooth rolls.


The Mill Tries to Catch Up with the Bins.

When the flour is made it is conveyed to large round bins--five sheets
of hard wood pressed together. These bins are being filled all the time
and being emptied all the time, the mill being about seven hours behind
the capacity of the bins, so that from start to finish the modern flour
mill is a tremendously busy place.

Underneath the bins and connecting with them are the flour
packers--automatic devices which pack a 3¹⁄₂-pound paper sack as
accurately as a 196-pound barrel. The filled packages are sent down
“chutes” to the shipping floor. There they go to wagons or through
other chutes to boats.




The Story in a Lead Pencil[5]

  [5] Courtesy of The Scientific American.


Why Do They Call Them Lead-pencils?

~WHERE LEAD PENCILS COME FROM~

The lead-pencil so generally used today is not, as its name would
imply, made from lead, but from graphite. It derives its name from
the fact that prior to the time when pencils were made from graphite,
metallic lead was employed for the purpose. Graphite was first used
in pencils after the discovery in 1565 of the famous Cumberland mine
in England. This graphite was of remarkable purity and could be used
without further treatment by cutting it into thin slabs and encasing
them in wood.


Who Made the First Lead-pencils in America?

For two centuries England enjoyed practically a monopoly of the
lead-pencil industry. In the eighteenth century, however, the
lead-pencil industry had found its way into Germany. In 1761, Caspar
Faber, in the village of Stein, near the ancient city of Nuremberg,
Bavaria, started in a modest way the manufacture of lead-pencils, and
Nuremberg became and remained the center of the lead-pencil industry
for more than a century. For five generations Faber’s descendants made
lead-pencils. Up to the present day they have continued to devote
their interest and energy to the development and perfection of pencil
making. Eberhard Faber, a great-grandson of Caspar Faber, immigrated
to this country, and, in 1849, established himself in New York City.
In 1861, when the war tariff first went into effect, he erected his
own pencil factory in New York City, and thus became the pioneer of
the lead-pencil industry in this country. Since then four other firms
have established pencil factories here. Wages, as compared to those
paid in Germany, were very high, and Eberhard Faber realized the
necessity of creating labor-saving machinery to overcome this handicap.
Many automatic machines were invented which greatly simplified the
methods of pencil making and improved the product. To-day American
manufacturers supply nine-tenths of the home demand and have largely
entered into the competition of the world’s markets.


What Are Lead-pencils Made of?

The principal raw materials that enter into the making of a
lead-pencil are graphite, clay, cedar and rubber. Although graphite
occurs in comparatively abundant quantities in many localities, it is
rarely of sufficient purity to be available for pencil making. Oxides
of iron, silicates and other impurities are found in the ore, all of
which must be carefully separated to insure a smooth, serviceable
material. The graphites found in Eastern Siberia, Mexico, Bohemia and
Ceylon are principally used by manufacturers.

  Pictures by courtesy Joseph Dixon Crucible Co.

[Illustration: FIG. 1.

FIG. 2.

FIG. 3.

Fig. 1 shows the shape in which the cedar slats arrive at the factory.
These slats after grading are boiled in steam to remove what remaining
sap there may be in the wood. The slats are then dried in steam-drying
rooms. Then the next step is grooving and gives the results shown by
Fig. 2. Now the wood is ready to receive the “leads” (which you will
remember are a mixture of graphite and clay), which are placed between
two slats sandwich fashion, glued, put in forms that hold them over
night under a thousand pounds pressure. Fig. 3 shows the leads laid in
one of the grooved slats.]


How Are Lead-pencils Made?

The graphite, as it comes from the mines, is broken into small pieces,
the impure particles being separated by hand. It is then finely
divided in large pulverizers and placed in tubs of water, so that the
lighter particles of graphite float off from the heavier particles of
impurities. This separating, in the cheaper grades, is also done by
means of centrifugal machines, but the results are not as satisfactory.
After separation, the graphite is filtered through filter-presses.


What Makes Some Pencils Hard and Others Soft?

The clay, after having been subjected to a similar process, is placed
in mixers with the graphite, in proportions dependent upon the grade
of hardness that is desired. A greater proportion of clay produces a
greater degree of hardness; a lesser proportion increases the softness.

[Illustration: FIG. 4.

FIG. 5.

FIG. 6.

Fig. 4 shows a prospective view of the block as it appears when taken
out of the form; the leads can be seen in the end. These blocks are fed
to machines which cut out the pencils in one operation. An idea of this
operation is given by Fig. 5, which shows a block half cut through. The
pencils come out quite smooth, but are sand-papered to a finer finish
before receiving the finishing coats. The finer grades of pencils are
given from seven to nine coats of varnish before being passed along for
the next process. Fig. 6 shows a pencil after it has been machined and
before it has been varnished and stamped.]

Furthermore, the requisite degree of hardness is obtained by the
subsequent operation, viz., the compressing of the lead and shaping it
into form ready to be glued into the wood casings. A highly compressed
lead will produce a pencil of greater wearing qualities, an important
feature in a high-grade pencil. Hydraulic presses are used for this
purpose; and the mixture of clay and graphite, which is still in a
plastic condition and has been formed into loaves, is placed into these
presses. The presses are provided with a die conforming to the caliber
of the lead desired, through which die the material is forced. The die
is usually cut from a sapphire or emerald or other very hard mineral
substance, so that it will not wear away too quickly from the friction
of the lead. The lead leaves the press in one continuous string, which
is cut into the lengths required (usually seven inches for the ordinary
size of pencil), is placed in crucibles, and fired in muffle furnaces.
The lead is now ready for use, and receives only a wooden case to
convert it into a pencil.


Where Does the Wooden Part of a Lead-pencil Come from?

The wood used in pencil making must be close and straight grained,
soft, so that it can readily be whittled, and capable of taking a good
polish. No better wood has been found than the red cedar, a native of
the United States, a durable, compact and fragrant wood to-day almost
exclusively used by pencil makers the world over. The best quality is
obtained from the Southern States, Florida and Alabama in particular.

The wood is cut into slats about 7 inches long, 2¹⁄₂ inches wide, and
¹⁄₄ inch thick. It is then thoroughly dried in kilns to separate the
excess of moisture and resin and to prevent subsequent warping. After
this the slats are passed through automatic grooving machines, each
slat receiving six semi-circular grooves, into which the leads are
placed, while a second slab with similar grooves is brushed with glue
and covered over the slat containing the leads. This is passed through
a molding-machine, which turns out pencils shaped in the form desired,
round, hexagon, etc. The pencils are now passed through sanding
machines, to provide them with a smooth surface.


How is the Color Put on the Outside of the Pencil?

After sand-papering, which is a necessary preliminary to the coloring
process, when fine finishes are desired, the pencils are varnished by
one of several methods. That most commonly employed is the mechanical
method by which the pencils are fed from hoppers one at a time through
small apertures just large enough to admit the pencil. The varnish is
applied to the pencil automatically while passing through, and the
pencils are then deposited on a long belt or drying pan. They are
carried slowly a distance of about twenty feet, the varnish deposited
on the pencils meanwhile drying, and are emptied into a receptacle.
When sufficient pencils have accumulated, they are taken back to the
hopper of the machine and the operation repeated. This is done as often
as is necessary to produce the desired finish. The better grades are
passed through ten times or more. Another method is that of dipping
in pans of varnish, the pencils being suspended by their ends from
frames, immersed their entire length and withdrawn very slowly by
machine. A smooth enameled effect is the result. The finest grades of
pencils are polished by hand. This work requires considerable deftness;
months of practice are necessary to develop a skilled workman. After
being varnished, the pencils are passed through machines by which the
accumulation of varnish is sand-papered from their ends. The ends
are then trimmed by very sharp knives to give them a clean, finished
appearance.

Stamping is the next operation. The gold or silver leaf is cut into
narrow strips and laid on the pencil, whereupon the pencil is placed in
a stamping press, and the heated steel die brought in contact with the
leaf, causing the latter to adhere to the pencil where the letters of
the die touch. The surplus leaf is removed, and, after a final cleaning
the pencil is ready to be boxed, unless it is to be further embellished
by the addition of a metal tip and rubber, or other attachment.


How is the Eraser Put On a Pencil?

In this country about nine-tenths of the pencils are provided with
rubber erasers. These are either glued into the wood with the lead, or
the pencils are provided with small metal ferrules threaded on one end,
into which the rubber eraser-plugs are inserted. These ferrules are
made from sheet brass, which is cupped by means of power presses, drawn
through subsequent operations into tubes of four- or five-inch lengths,
cut to the required size, threaded and nickel-plated.

[Illustration:

  Courtesy of Doubleday, Page & Co.

A SOUTHERN COTTON FIELD]




The Story in a Bale of Cotton


Where Does Cotton Come From?

We get cotton from a plant which grows best in the warm climate of our
Southern States. Cotton has been known to the people of the world for
a long time. Before the birth of Christ people knew about cotton. They
thought it was wool which grew on a tree instead of a sheep’s back.
No other plant is of such value to man as cotton. We should learn
something about a plant that is used by man in so many ways as cotton.

The cotton plant of our Southern States is a small shrub-like annual
about four feet high. The flowers of the cotton plant are white at
first but change to cream color and then are tinged with red. This
change takes place over a period of four days when the petals drop off
and leave what is called a “boll” in the calyx of the flower. This
boll, which is to contain the cotton, is really the seed container of
the cotton plant and keeps on growing larger until it is about as big
as a hen’s egg. When it is fully grown or ripe the boll cracks and the
seeds and fibrous lint burst forth. The bolls are then gathered and
taken to a cotton gin, where the seeds are separated from the lint and
the lint prepared for weaving.

The boll is divided into from three to five sections. Each section
contains a quantity of lint and seeds. When the boll is fully grown
the covering of each of the sections cracks and opens up, revealing
the contents. It is just like opening the door of each section and
having the contents burst out. When these bolls burst open, there is no
more beautiful sight in the world than to look out over a cotton field
and see the colored people--the “cotton pickers”--busy at their work
picking off the bolls.

When the crop is gathered and ginned, the lint is packed into bales and
taken to the cotton mill, where it is made into cloth. One of the most
interesting industrial processes in the world is to see the bale of
cotton go into a cotton mill and come out a piece of cotton goods.

[Illustration: THE COTTON ARRIVES AT THE MILL

BALES OF COTTON AT COTTON MILL]

[Illustration: OPENING MACHINES.

The bales are opened, and the cotton is thrown into the large hoppers
at the front of these machines, which open and loosen the fibers,
work out lumps and remove the grosser impurities, such as dirt, leaf,
seed and trash. A strong air draft carries off the dust and foreign
particles, and lifts the cotton through trunks to the floor above.]

[Illustration: LAPPER MACHINES.

In these machines, known as Breaker and Finisher Lappers, more of the
trash and impurities is beaten out of the cotton, and the lint is
carried forward and wound into rolls of cotton batting, known as laps.
Several of these are doubled and drawn into one so as to get the weight
of each yard as uniform as possible.]

[Illustration: FIRST STEPS IN MAKING COTTON CLOTH

CARD ROOM.

In these machines, known as Revolving Flat Top Cards, the cotton passes
over revolving cylinders clothed with wire teeth, and the fibers are
combed out and laid parallel with each other. They are delivered at the
front of the machine as a filmy web, which is gathered together and
formed into a soft downy ribbon or rope, known as card sliver. This is
automatically coiled and delivered into cans.]

[Illustration: DRAWING FRAMES.

To insure uniformity in weight, so that the yarn when spun shall run
even, the card slivers are doubled and drawn out, redoubled and again
drawn out, somewhat in the manner of a candy maker pulling taffy, only
here the process is continuous. Six strands of the card sliver are fed
in together at the back of the drawing frames, pulled out and delivered
as one; and the process repeated. This produces a sliver more uniform
in weight, and in which the fibres are more parallel.]

[Illustration: SLUBBERS.

The sliver from the drawing frames is taken to machines called
slubbers, where again the fibers are drawn out, and the strand of
cotton, now much finer and known as slubber roving, is given a bit of
twist to hold it together, and is wound on large bobbins.]

[Illustration: PUTTING THE COTTON FIBER ON BOBBINS

SPEEDERS.

The large bobbins of roving from the slubbers are taken to other
machines known as Speeders, and are unwound through the machine, again
drawn out finer and finer, and rewound on smaller bobbins. The strand
of cotton known as speeder roving is now ready to be taken to the
spinning room for the final draft and twist necessary to turn it into
yarn.]

[Illustration: SPINNING FRAMES.

The roving from the speeders is placed on the Spinning Frames, and now
undergoes its final draft as it passes through the spinning rolls. The
attenuated fibres are then twisted firmly together by the action of the
spindles, which turn at a speed of about 10,000 revolutions per minute.
The yarn thus formed is wound on bobbins and is ready to be dyed and
weaved.]

[Illustration: THE COTTON IS READY FOR DYEING

SPOOLERS.

Two kinds of yarn are delivered at the spinning frames, known as warp
and filling, which make respectively the lengthwise and crosswise
threads of the cloth. The filling is in its completed form ready for
the loom; the warp must first be gotten into shape for dyeing and then
arranged in parallel rows or sheets of thread for weaving. The first of
these processes is spooling, and consists simply in unwinding the yarn
from the small bobbins on which it is spun, and rewinding it on large
spools.]

[Illustration: WARPERS.

The spools of warp yarn are placed in large wooden racks or creels from
which they can conveniently unwind. The separate threads are drawn
through little wires in the warpers, and are gathered into a bunch or
rope of threads, which is wound in a large cylindrical ball known as a
warp. If any thread breaks while passing through the warper, the little
wire drops and stops the machine. In this way full count of threads and
uniform weight of the goods is insured.]

[Illustration: DYE-HOUSE.

Here the warps, after being boiled and softened to enable the dye to
penetrate, are passed through the indigo vats. Several runs are made to
get the beautiful depth of color. This Dye-house is equipped with one
hundred indigo vats, and is one of the best-lighted and cleanest-kept
dye-houses in the world.]

[Illustration: WHERE THE COTTON IS WOVEN INTO CLOTH

BEAMING FRAMES.

After being dyed, the warps are washed and then passed through drying
machinery, from which they are delivered in coils. These are brought
to the beaming frames, where they are again spread out into sheets of
parallel threads, and passed through the teeth of a steel comb, which
separates the threads and prevents tangling, and in this form they are
wound on huge iron spools known as slasher beams.]

[Illustration: SLASHERS.

From the beaming frames the warps are taken to machines known as
Slashers, where they are sized or stiffened to enable them to stand the
chafing at the looms incidental to the process of weaving. The slasher
beams are placed in an iron frame at the back of the slashers and
unwound together through the machine. With them some additional threads
of white yarn are unwound at either side to form the selvage of the
cloth.]

[Illustration: WEAVE ROOM.

The sheet of warp threads unwinds from the loom beam, receives the
filling threads and is wound into a roll of cloth at the front of the
loom. This weave room contains 2000 looms. It is 904 feet long by 180
feet wide (about four acres) and is the largest single weave room in
the world. Overhead is the roof, which forms one vast sky-light, being
of what is known as saw-tooth construction. The vertical sides of the
teeth all face due north and are formed of ribbed glass, which affords
the most perfect light to every section of the room.]

[Illustration: THE COTTON CLOTH FINISHED

INSPECTING TABLES.

Before going to the baling presses every yard of cotton cloth passes
under the vigilant eyes of the cloth inspectors, who mark as seconds
and lay aside all pieces containing imperfections. This inspection
is not a mere formality, but is conducted most carefully, and this
department is specially located to get the best and most perfect light.]

[Illustration: BALING PRESSES.

The bolts of finished cloth are now placed in presses and made into
bales of finished cloth and are ready for the market.]

[Illustration: Shipping platform of the White Oak Mills, Greensboro, N.
C., showing how the bales of finished cloth are handled in shipping.]

  Pictures herewith by courtesy of White Oak Mills.


Who Discovered Cotton?

Just who discovered cotton is not known. The early records are so
incomplete that no individual can be credited with the discovery of
the value of this wonderful plant. Long before Cæsar’s time, among the
Hindoos they had a law that if you stole a piece of cotton you were
fined three times its value. Most of the early nations were familiar
with cotton--the early Egyptians, Chinese and other ancient people used
it and valued it.


What Nation Produces the Most Cotton?

The United States is the leader in the production of cotton, as in many
other important world products. We produce more than seventy-five per
cent of all the cotton grown in the world. The remainder is practically
all grown by East India, Egypt and Brazil.


What is Cotton Used For?

The cotton plant is one of the wonder plants of the world, when you
stop to think how well we could get along without wool or silk or other
fabrics if we had to.

Little would be lost to the world so far as actual comfort is concerned
if all of the other fabric-making materials were lost. We would sleep,
as we often do now, in beds the coverings of which were pure cotton,
in a room in which the rugs were woven from cotton, the sun kept out
of the room by cotton window shades. We could still have plenty of
good soap to wash our bodies and clothing, for much of our soap to-day
is made from cotton-seed oil; then we could use a cotton towel to dry
ourselves; and put on a complete outfit of clothing made entirely of
cotton. White cotton table cloths and napkins are not so fine as linen;
they are good enough for anyone. Your breakfast rolls will taste quite
as well if baked with cottolene instead of lard; the meat for your
dinner would be fed and fattened on cotton-seed meal and hulls as they
are now; you would have butter made from cotton-seed that compares
favorably with the butter you now have on the table; the tobacco in
your cigar would continue to be grown under cotton cloth and packed in
cotton bags; armies would still sleep under cotton tents and could use
gun-cotton to destroy the enemy.


What Are the Principal Cotton Cloths?

There are a great many different names given to cotton cloths, but
they may in general be divided into five classes--plain goods, twills,
sateen, fancy cloth and jacquard fabrics. The cotton cloth in each of
these classes varies and goes by different names. For instance, in
Plain Goods, the different kinds are lawn, nainsook, sheeting, mull,
print cloth, madras. The difference lies in the number of threads in
one inch of width, the fineness and the weave. The Twills have lines
running diagonally and are used for linings mostly. The difference
is in the weaving. Denim, largely used for overalls, belongs to the
class of Twills. Sateen is used for dress linings, dresses and waists.
Then there is the class of Fancy Cloths which is another kind of weave
used largely in children’s clothes, shirt waists, etc., and under
the name Scrim is fine for draperies and towelling. The other class,
Jacquard Fabrics, represents the most complicated form of weaving and
used largely under special individual names or brands for dress goods,
novelties, etc.


How Much Cotton Cloth Will a Pound of Cotton Make?

When the cotton is spun into yarn it is no longer sold by the bale, but
by the pound. It is impossible to make an exact statement of the amount
of cotton cloth one pound of cotton yarn will make, because of the
difference in weaving. It has, however, been figured out that a pound
of cotton yarn should make

  3¹⁄₂ yards of sheeting, or
  3³⁄₄ yards of muslin, or
  9¹⁄₂ yards of lawn, or
  7¹⁄₂ yards of calico, or
  5¹⁄₂ yards of gingham, or
  57 spools of thread.

[Illustration:

  Picture by courtesy Browne & Howell Co.

CHRISTOFORI PIANO FROM THE METROPOLITAN MUSEUM OF ART, NEW YORK CITY.]




The Story in a Piano


What is Music?

Music is one kind of sound. All sounds, whether musical or not, are the
result of sound waves in the air. They travel almost exactly like the
waves of the water. They go in circles in all directions at the same
speed and will go on forever unless they meet something that has the
ability to stop them. If you drop a pebble into the exact center of a
basin of water, you will see the ring of waves produced start from the
point where the pebble entered the water and travel to the sides of the
vessel, which stop them. Also the pebble as it falls into the water
will make ring after ring of waves.

When you shout or ring or strike one of the keys of the piano you start
a sound wave or a series of them, which you can hear as soon as the
sound wave strikes your ear. When the series of waves is regular the
sound produced is a musical sound, and when the sound waves are not
regular in length we call it some other kind of a sound.

Acting on the knowledge so learned, man has devised numerous
instruments with which he can produce musical sounds, such as the
piano, phonograph, and many others.


Who Made the First Piano?

The first real piano was made by Bartolomeo Christofori, an Italian.
He invented the little hammers by the aid of which the strings are
struck, giving a clear tone instead of the scratching sound which
all the previous instruments produced. It took two thousand years to
discover the value of the little hammers in making clearer notes. His
first piano was made in 1709. The word by which we call the instrument
pianoforte has, however, been traced back as far as 1598, when it is
said to have been originated by an Italian named Paliarino. The first
piano made in America was produced by John Behnud, in Philadelphia, in
1775.


How Was the Piano Discovered?

~THE DISCOVERY OF STRINGED MUSICAL INSTRUMENTS~

The piano is a stringed musical instrument. The name pianoforte comes
from two Italian words meaning _soft_ and _loud_, and is accurately
descriptive of the piano because the notes can at will be made soft or
loud. The piano is a development of the simplest form of making regular
sound vibrations by snapping or hammering a string of some kind which
is stretched tight and fastened at both ends. We must go far back into
history to find the earliest traces of stringed instruments, and even
then we do not know where and when they originated, for there seem to
be no records which help us to trace their origin. We know that the
Egyptians as far back as 525 B.C. had stringed instruments, but we only
know they had them--not where they got them or who made them. There
is a legend that the Roman god Mercury, while walking along the Nile
after the river had overflowed its banks and the land had again become
dry, stubbed his toe on the shell of a dead tortoise. He picked it up
to cast it aside and accidentally touched some strings of sinew with
his finger. These strings were only what remained of the once live
tortoise. At the same time Mercury heard a musical note and, after
vainly trying to find a cause for the musical sound, twanged the string
again and discovered the music in tightly-stretched strings. He set
about making an instrument, using the tortoise shell for the sound box
and stretching a number of strings of sinew across it. This is only a
legend, of course, but if we examine the early musical instruments of
the Greeks, which was the lyre, we always find the representation of a
tortoise upon it.

Other nations, such as the early Chinese, the Persians, the Hindus and
the Hebrews, had stringed instruments much resembling the lyre. In the
tombs of the great rulers of Egypt are found representations of harps,
and one harp which had been buried in one of the tombs for more than
3000 years was actually found to be in good condition.

[Illustration: Picture by courtesy Browne & Howell Co.

DULCIMER.]

Wherever we search among the records of early nations we find evidence
that they were familiar with the music obtainable from playing upon
stringed instruments, but we have never been able to discover what
people or what persons first learned that music could be produced with
such instruments.

~THE FIRST STRINGED MUSICAL INSTRUMENT~

The harp was probably the first practical stringed instrument. Its
music was produced by picking the strings with the fingers or with a
piece of bone or metal.

The next step was the psaltery, which was produced in the Middle Ages.
It was a box with strings stretched across it and represented the first
crude attempt at using a sounding board. A larger instrument which came
about the same time and was very like the psaltery, was the dulcimer.
Both were played by picking the strings with the finger or a small
piece of bone or other substance.

Then came the keyboard, first used on stringed instruments in what
is called the _clavicytherium_. This consisted of a box with cat-gut
strings ranged in a semitriangle. On the end of each key was a quill,
which picked the string when the key was operated.

After this came the clavichord. It was built like a small square piano
without legs. The strings were made of brass and on the end of each key
was a wedge-shaped piece of brass which picked the strings. The elder
Bach composed his music on the clavichord, his favorite instrument, and
that is why the music written by Bach is full of soft and melancholy
notes. The clavichord produced only such notes.

The next steps brought the virginal, spinet and harpsichord. The
strings on all three were of brass with quills at the key ends for
picking the strings. The virginal and spinet were very much alike. The
harpsichord was larger and sometimes was made with two keyboards. These
instruments had notes covering four octaves only.

[Illustration: Picture by courtesy Browne & Howell Co.

CLAVICHORD.]

The arrangement of the strings in the harpsichord provided one step
nearer to our piano. It had five octaves of notes and there were at
least two strings to each note instead of only one, as in previous
instruments.

[Illustration: Picture by courtesy Browne & Howell Co.

SPINET.]


Why Do We Have Only Seven Octaves On a Piano? Why Not Twelve or More
Octaves?

Ordinarily the longest key-board of the piano has seven octaves and
three notes in addition, or 52 notes, not counting the sharps and
flats. An octave you, of course, know consists of the seven notes C D
E F G A B. Every eighth note is a repetition of the one seven notes
below or above. The reason that there are no more notes or octaves on
the piano is that if we extended the key-board either way one or two
octaves more, we should not be able to hear the notes struck on the
keys. There would be sound produced, or course, but the vibrations
would be too fine for the human ear to hear. It is said that the range
of the human ear does not go beyond somewhere between eleven and twelve
octaves.

[Illustration: Picture by courtesy Browne & Howell Co.

UPRIGHT HARPSICHORD.

(From the Metropolitan Museum of Art, New York City.)]

[Illustration:

  Picture by courtesy Browne & Howell Co.

QUEEN ELIZABETH’S VIRGINAL.]

[Illustration: HOW THE MUSIC GETS INTO THE PIANO

  Photo by Kohler & Campbell Piano Co.

PUTTING ON THE SOUNDING BOARD.

The first operation in producing the piano is to make a wooden frame
or back on which is attached first the sounding board, then the iron,
harp-shaped frame to which the strings are fastened.

The tones of the piano are produced by felt-covered hammers striking
the strings. The sounding board, which is made of wood, magnifies the
tones.

This picture shows the mechanics glueing the sounding board to the
back.]

[Illustration:

  Photo by Kohler & Campbell Piano Co.

FASTENING THE STRINGS.

The strings are hitched on to pins in the iron frame at its lower end
and fastened at the upper end by a metal pin or peg driven into the
back. The peg is square on top, so that it can be turned with a tuning
hammer or wrench in order to tighten or slacken the strings, which is
the operation of tuning the piano.]

[Illustration: THE LITTLE HAMMERS WHICH STRIKE THE PIANO STRINGS

  Photo by Kohler & Campbell Piano Co.

BUILDING THE CASE AROUND THE SOUNDING BOARD.

As soon as the sounding board with its iron frame and strings is
complete, the outside case is built up around it, the front being left
open to receive the action and key-board.]

[Illustration:

  Photo by Kohler & Campbell Piano Co.

ATTACHING THE LITTLE HAMMERS THAT STRIKE THE STRINGS.

In this picture the workmen are placing the action and keys, to which
are attached the little wooden felt-covered hammers, which will strike
the strings and produce the tones. It took a great many years for our
musical instrument makers to hit upon the idea of using these little
hammers, and thus make the piano a perfect instrument.]

[Illustration: REGULATING THE ACTION OF THE PIANO

  Photo by Kohler & Campbell Piano Co.

REGULATING THE ACTION AND KEYBOARD.

This picture shows the piano partly assembled and the workmen adjusting
each little black and white key to the proper touch.]

[Illustration:

  Photo by Kohler & Campbell Piano Co.

TUNING, POLISHING AND FINISHING.

The piano is now complete except for polishing and tuning. The tuning
is left to the last. The tuner must have a good ear for music. With
his key he tightens or loosens each of the pegs to which the wires are
attached until it is perfectly in tune and all in harmony. The piano is
now ready to play upon.]




How Sounds Are Produced.


If you look closely at a tuning fork, or a piano string, while it
is sounding, you can see that it is swinging rapidly to and fro, or
vibrating. Touch it with your finger and thus stop its vibration and it
no longer produces sound. The only difference that you can discover in
the fork or string when sounding and when silent is that when you stop
the motion it is silent and when it vibrates it makes a sound. From
this we learn that the sounds are due to the vibrations of sounding
bodies. This has been proven by the examination of so many sounding
bodies that we believe that all sounds are produced by vibrations.

The question that next presents itself is, how the vibrations affect
our ears, so as to produce the sensation of hearing. This may be made
clear by a very simple, but striking, experiment. If a bell which has
been arranged to be rung by clock-work is suspended under the receiver
of an air pump, and the air pumped out, the sound of the bell will grow
faint as the quantity of air in the receiver decreases, and finally
will stop completely. By looking through the glass of the receiver,
however, the bell may be seen ringing as vigorously as at first. We
learn thus that the air around a sounding body plays an important part
in the transmission of the vibrations to our ears. The way in which
the air acts in transmitting the vibrations is as follows. At each
vibration of the sounding body, it compresses, to a certain degree,
a layer of air in front of it. This layer, however, does not remain
compressed, for air is very elastic, and the compressed air soon
expands, and in doing so compresses a layer of air just beyond it. This
layer expands in its turn, and compresses another layer still further
from the body. In this way waves of compression are sent through the
air, at each vibration, in all directions from the vibrating body.

It must not be thought that particles of air travel all the way from
the vibrating body to the ear when a sound is heard. Each particle of
air travels a very short distance, never any further than the vibrating
body moves in making a vibration, and the movement of the air particles
is a vibratory one, like that of the sounding body. But the particles
of air near the sounding body communicate their vibrations to other
particles, further from that body, and these, in turn, to others still
further away, so, while the particles of air themselves move very short
distances, the waves produced by their vibrations may be made to travel
a considerable distance.

The size of a sound wave ordinarily is very small, but sound waves are
sometimes made of such size and strength as to strike our ears with
a force sufficient to rupture the ear drum. Such large and forceful
waves come during explosions, such as the discharges of cannon or the
explosions of large quantities of gunpowder under any conditions.




What Is Sound?


From what has already been said, you will probably answer that sounds
are waves in the air, which produce the sensation of hearing. This
is correct, but sound is not limited to vibrations of the air. Other
elastic substances can be made to vibrate in the same way, and the
waves so produced when conveyed to our ears, produce the sensation of
hearing. If you put your ear under water and then strike two stones
together in the water you will hear a sound as readily as you would in
air. Sound waves may be transmitted by solid bodies also, and some of
these are better for this purpose than air or liquids. Perhaps you have
tried the experiment of placing your ear against one of the steel rails
on a railroad track to listen for the coming of a distant train. If you
have tried this, you know that a sound that is too faint, or is made
too far away, to be heard through the air, can easily be heard through
the rail.

In view of the fact that other substances than air can be thrown into
waves that will affect the sense of hearing, we may define sound as
vibrations in any elastic object, that produces the sensation of
hearing.

The definition is sometimes called the physical definition of sound,
in contradistinction to the physiological definition of sound which
is given as the sensation produced when vibrations in elastic
substances are conveyed to our ears. You will see then that sound when
referring to the physical definition is what makes sound known in the
physiological definition. The term sound alone, without qualifications,
may have either meaning, and therefore statements concerning sound may
be misleading, unless we are exact in explaining the sense in which the
word is used.




How Fast Does Sound Travel?


When a sound is made close to us, it reaches our ears so quickly that
it seems as though it took no time to travel; but when a gun is fired
by a person at a distance, you will notice that after you see the flash
of the gun, a little time elapses before the sound reaches your ear. It
takes a little time for the light from the flash to get to your eyes,
but a very short time, which you cannot appreciate. Sound travels much
more slowly and the time it takes to travel a few hundred yards is
noticeable. Accurate measurements of the speed of sound have been made,
and it has been found that sound usually travels in air at a speed of
about eleven hundred feet a second. The speed is not always the same,
however, for a number of circumstances may cause it to vary. In air
which is heated, the speed at which sound travels in it is increased
because hot air expands. At the freezing point, sound travels through
the air at the rate of 1,091 feet a second, and for every increase
in temperature of one degree of heat, the speed is increased about
thirteen inches a second. Accordingly at 68° F. the speed would be
approximately 1,130 feet a second. Sounds also travel faster in moist
air than in dry.

In other gases the speed of sound transmission may be greater or less
than in air. For example, in hydrogen gas, which is much lighter than
air, sound travels nearly four times as fast as it does in air. On the
other hand, in carbonic acid gas, which is heavier than air, sound is
transmitted more slowly.

In liquids, which are always heavier than air, you would naturally
think that sound would travel more slowly than in air, but this is not
true. Liquids are less compressible than gases and this causes the
speed with which sound is transmitted in them to be increased. In water
sound travels about four times as fast as in air.




What Are the Properties of Sound?


Sounds differ from each other by the extent to which they possess three
qualities, namely; intensity, pitch and quality.

The intensity of any sound that we hear depends upon the size of
the waves that reach our ears. The size of a sound wave gradually
decreases, as the wave travels from its starting point, consequently
the intensity of a sound depends upon the distance from the point
at which the sound was produced. We know this from experience and
if we think of the matter for a moment we will see why it is so. At
the start of a sound wave, only a small quantity of air is affected,
but for every inch it travels the quantity of air to which the wave
is conveyed becomes larger, and the intensity of the waves must grow
correspondingly smaller, just as when a pebble is dropped into water,
the ripples produced by it are highest at the point where the pebble
struck the water, and grows lower and lower as their circle widens.

It has been found possible to measure the intensity of a sound wave,
at different distances from the point from which it started, and from
these measurements it has been learned that the decrease in the open
air, follows a fixed rule that is stated thus: the intensity of a
sound wave at any point is inversely proportional to the square of
its distance from its starting point. This rule is called “the law
of inverse square,” and it means that if the intensity of a wave be
measured at two points, distant say one hundred, and two hundred yards,
respectively, from the starting point of the sound, the intensity of
the sound at the first point will be found to be four times as great as
at the second point.




Why Can You Hear More Easily Through a Speaking Tube?


We have seen that the decrease in intensity of a sound wave as it
travels through the air, is due to the fact that the quantity of
air set in motion by it is constantly increasing. But, if a wave is
conveyed through a tube containing air, the quantity of air to which
the vibrations are communicated does not increase as the wave travels
forward, and theoretically there is no decrease in intensity. When a
wave is actually transmitted in this way, however, it is found that
there is some decrease in intensity on account of the friction of the
particles of air against the sides of the tube; but the decrease from
this cause is much slower than that which occurs in the open air, and
consequently sounds can be heard at much greater distances through
tubes than through the open air. Tubes for speaking purposes are
frequently used to connect different parts of the same building, and if
the tubes are not too crooked they serve their purpose very well.

Pitch is that property of sounds that determines whether they are high
or low. The pitch of a sound depends upon the number of vibrations
a second which the body that produces it makes. The sound of an
explosion has no pitch because it makes but one wave in the air. The
sound made by a wagon on a pavement has no definite pitch, for it is
a mixture of sounds, in which the number of vibrations per second is
not the same. Pitch is a property of continuous sounds only, and it is
apparent chiefly in musical sounds, by which we mean sounds in which
the vibrations are continuous and regular. In music, however, pitch
is very important. In a musical instrument, the parts are so arranged
that the sounds produced can be given any desired pitch, and it is by
controlling the pitch that the pleasing effect of musical sounds in
large measure is produced. Sounds of low pitch are produced by bodies
making but a few vibrations a second while high-pitched sounds are made
by bodies that vibrate rapidly.

Quality, may be defined as that property of sounds which enable us to
distinguish the notes produced by different instruments. Two notes,
one of which is produced upon a piano, and the other upon a violin,
may have the same pitch and be equally loud, yet they are easily
distinguishable. The difference in them is due to the presence of what
are called overtones.




What Is Meant By the Length of Sound Waves?


The length of a sound wave embraces the distance from the point of
greatest compression in one wave to the same point in the next. This
depends upon the pitch for if a sounding body is making one hundred
vibrations a second, by the time the one hundredth vibration is made,
the wave from the first vibration will have travelled about eleven
hundred feet from the starting point, and the remaining ninety-eight
waves will lie between the first and the one hundredth. In consequence
of this, the wave length for that particular sound will be about eleven
feet. If the sounding body had made eleven hundred vibrations a second
by the time the first wave had travelled eleven hundred feet, there
would have been eleven hundred waves produced, and the wave length for
that sound would be one foot. The wave lengths of sounds produced by
the human voice usually lay between one and eight feet, though some
singers have produced notes having wave lengths as great as eighteen
feet, and others have reached notes so high that the wave length was
only about nine inches.

When a tuning fork is struck, it produces a sound so faint that it can
scarcely be heard unless the fork is held near the ear; but if the end
of the fork is held on a box or table, the sound rings out loudly and
seems to come from the table. The explanation of this is very simple.
When only the fork vibrates, it produces very small sound waves,
because its prongs are small and cut through the air. But when it is
set on a box or table, its vibrations are communicated to the support,
and the broader surface of the box or table sets a larger mass of air
in vibration, and so amplifies the sound of the fork. When a surface
is used in this way to reinforce the vibrations of a small body, and
thus produce sound waves of greater volume, it is called a sounding
board. Many musical instruments, like the violin and the piano, owe
the intensity of their sounds to sounding boards, which reinforce the
vibrations of their strings.

~WHAT A SOUNDING BOARD DOES~

Columns of air, like sounding boards, serve to reinforce sound waves.
Unlike sounding boards, however, they do not respond equally well to a
large number of different sounds. They respond to one sound only, or
to several widely different ones. This may be shown as follows: Take a
glass tube about sixteen inches long, and two inches in diameter, and
after thrusting one end of it into a vessel of water, hold a vibrating
tuning fork over the other end. By gradually lowering the tube into the
water a point will be reached at which the sound becomes very loud, and
as this point is passed the sound gradually dies away again. By raising
the tube again the sound is again made loud when the tube reaches a
certain point. This shows that to reinforce sound waves of a certain
vibration frequency, the column of air in the tube must be of certain
length.

Let us now see why the waves produced by the tuning fork are reinforced
only by a column of air of a certain length. When the prongs of the
fork make a vibration, a wave of air is produced which enters the tube,
goes down to the water, is reflected, and comes back toward the fork.
Now, if the reflected wave reaches the fork at the precise moment when
it has completed one-half of its vibration and is about to begin upon
the second half, it will strengthen the wave produced by the second
half of the vibration; but if the reflected wave reaches the fork
before or after the beginning of the second half of the vibration, it
will not reinforce it. At the downward movement of the lower prong of
the tuning fork, a wave of compression is sent down into the tube, and
is reflected at the surface of the water. In order to reinforce the
wave produced by the prong when it moves upward, the reflected wave
must reach the fork just at the time that the prong reaches its normal
position and before it starts upon the second half of its vibration.

Not only do columns of air tend to reinforce notes having a certain
rate of vibration, but all elastic bodies have a certain rate at which
they tend to vibrate, and when sounds having the same rate of vibration
are produced near them, these bodies will vibrate in sympathy with
them. If the sounds be kept up long enough, the sympathetic vibrations
in objects near them sometimes become so great that they can easily be
seen. Goblets and tumblers made of thin glass show this property very
strikingly. When the proper notes are sounded the glasses take up the
vibrations, and give a sound of the same pitch. If the note is loud,
and is continued for some time, the vibrations of a glass sometimes
become so great that the glass breaks. Large buildings, and bridges
also, have rates at which they tend to vibrate, and this fact is the
foundation for the old saying, that a man may fiddle a bridge down, if
he fiddles long enough.




Musical Instruments.


By musical sounds, are meant sounds that are pleasant to hear, and
their combination in such a way that their effect is agreeable
produces music. Any instrument, therefore, that is capable of producing
pleasing sounds may be called a musical instrument, and music is
sometimes produced by very odd devices; but by musical instruments we
ordinarily mean instruments that are especially designed to produce
musical sounds. The number of such instruments that have been invented
is enormous, but all of them may be divided into comparatively few
classes, only two of which are of much importance. The two classes,
only two of which are of much importance. The two classes referred to
are stringed instruments and wind instruments.

~WHAT PITCH IS IN MUSIC~

Stringed musical instruments are those in which the sounds are produced
by the vibration of a number of strings, and are generally reinforced
by a sounding board. The strings are arranged in the instruments in
such a way that the pitch of the sound produced by each string shall
bear relation to the pitch of those obtained from the other strings. As
long as this relation exists, the instrument is said to be in tune, and
when the relation is destroyed, the instrument is out of tune, and the
music produced by it is apt to contain what we call discords.

The conditions that determine the pitch of sounds produced by strings
can be very easily discovered by experiment. Thus, by taking two pieces
of the same wire, one twice as long as the other, and stretching them
equally, you will observe on striking them that the shorter one yields
the higher note. If their vibration frequencies are measured it will
be found that the shorter string has a vibration frequency just twice
as great as that of the longer string. From this we conclude that when
two strings of the same size (and material) are stretched equally taut,
their vibration frequencies are inversely proportional to their lengths.

By now taking two pieces of wire, of the same size and length, and
stretching them so that the tension of one is four times as great as
that of the other, we shall find that the vibration frequency of the
tighter string is just twice as great as that of the looser. Thus, we
see that the vibration frequency depends upon the tension applied to a
string, and, that in strings of the same size and length, the vibration
frequencies are proportional to the square roots of their tensions.

Now taking two strings of the same length, but with the diameter of one
twice as great as that of the other, and stretching them equally, we
shall find that the vibration frequency of the smaller string is twice
that of the larger; which shows that when the lengths and tensions
of two strings are equal, their vibration frequencies are inversely
proportional to their diameters.

In constructing stringed instruments, advantage is taken of each
of these conditions that affect the vibration of strings, and the
requisite pitch is secured in a string by choosing one of convenient
length and diameter, and by stretching it to just the right tension.

When a string is plucked in the middle, it vibrates as a whole, and
its rate of vibration, or vibration frequency, is determined by the
three conditions that have just been discussed; but if a finger is
laid on the string, in the middle, and the string is plucked between
the middle and the end, the string will vibrate in halves, and the
middle point will remain at rest. If the string had been touched at a
point one-fourth of the length from the end it would have vibrated in
fourths, and there would have been three stationary points.

When vibrations are set up in a string, with nothing to prevent the
free vibration of the whole string, it first vibrates as a whole, and
the sound produced is known as the fundamental tone of the string; but
very soon smaller vibrations of segments of the string begin, first
of halves of the string, then of thirds, and then of fourths. These
smaller vibrations produce sound waves that blend with the fundamental
tone and are known as overtones. The combined sound of the fundamental
tone and the overtones is called a note. The overtones present in
notes that have the same fundamental tone are not the same when the
notes are produced by different instruments, and, consequently,
the sound of notes of the same pitch is not the same on different
instruments. This difference in notes of the same pitch has already
been mentioned, but the way in which overtones are produced was not
explained in connection with it.

In wind instruments the sounds are produced by the vibrations of
columns of air in pipes. In the organ, which is probably the best
example of a wind instrument, the vibrations are usually produced by
causing a current of air to strike a sharp edge, just above the opening
of the pipe, as is done in a common whistle. A portion of the air
current is deflected into the organ pipe, and it sets up vibrations in
the air within the pipe.

The pitch of the sound produced by an organ pipe is determined by the
length of the pipe. A pipe that is open at both ends, called an open
pipe, produces a sound that has a wave length twice as great as the
length of the pipe; and if the pipe is open at one end only, a closed
pipe, the sound produced has a wave length twice the length of the open
pipe. Hence it will be seen that a closed pipe produces a sound that
has the same pitch as that produced by an open pipe that is twice as
long.




Talking Machines.


The phonograph, graphophone, gramophone, sonophone, and other talking
machines, furnish one of the best proofs of the wave theory of sound,
because their invention was based upon that theory. The first talking
machine was that invented by Thomas A. Edison and called by him the
phonograph. The others merely show the principle of the phonograph
applied in different ways, and need not be separately described. The
reasoning that led Edison to invent the phonograph was that if the
sound waves produced by the human voice were allowed to strike a thick
disk of hard rubber or metal, they would cause the disk to vibrate in
a certain way, and if the disk were again made to vibrate as it had
done under the influence of the voice, the sounds of the voice would be
reproduced. The difficult part of the task of making a talking machine
was in finding a way to make the disk vibrate again as it did under
the influence of the voice. This, however, was finally accomplished,
providing the disk with a needle, that rests on a cylinder of hard
wax, which turns slowly under the point of the needle while the sound
waves are striking the disk. The vibrations of the disk cause the point
to indent the surface of the wax so as to produce a groove of varying
depth on its surface. After the vibrations of the speaker’s voice have
been recorded in this way on the surface of the wax cylinder the needle
can be made to retrace its path, and will cause the disk to vibrate as
it did under the tones of the speaker’s voice. These last vibrations of
the disk produce sound waves similar to those of the voice, but their
amplitude is less and the sound is not so loud.




Why Does Red Make a Bull Angry?


It is very doubtful if a red flag really makes a bull more excited or
more quickly than a rag of any other color or any other object which
the bull can see plainly but does not understand. Conceding for the
moment that red excites a bull more than any other color, the answer to
the question will be found in the statement that anything unusual which
the bull sees has a tendency to make him angry and the thing which he
can see at a distance more quickly will start him going most quickly.
He can see a red rag better perhaps than almost any other color. There
may be something about the color which excites him just as some notes
on the piano will worry some dogs, but there is no way of studying the
bull’s anatomy to determine why red should excite him more than any
other color, if that is so.

[Illustration: FIG. 1.]

[Illustration: FIG. 2.]

[Illustration: FIG. 3.]




HOW A KEY TURNS A LOCK


What Happens When the Knob is Turned?

All of that portion of the lock which is shown above the round central
post is operated by the knob, the spindle of which passes through the
square hole. Before the knob is turned, the parts are in the position
shown in figure 2, with the latch bolt protruding. Turning the knob to
the left gives the position shown in figure 1, the upper lever in the
hub pushing back the yoke, which in turn pushes back the latch bolt.
When the hand is removed, the springs cause the parts to return to the
position shown in figure 2. Turning the knob to the right also retracts
the latch bolt, as shown in figure 3, by means of the lower lever on
the hub.

The spiral spring on the latch bolt is lighter than the one above
it. This gives an easy, lively action to the bolt, with very little
friction when the door is closed, while the heavier spring above gives
a quick and positive action of the knobs.


What Happens When the Key is Turned?

All of that portion of the lock which is shown below the round central
post is operated by the key. The square stud is attached to the bolt,
and in figure 1, it is seen that the projections on the flat tumblers
prevent the stud from moving forward, holding the bolt in retracted
position. When the key is turned as shown in figure 2, it raises the
tumblers releasing the stud, and then pushes the bolt out, the tumblers
falling into position as shown in figure 3, with the projections
again engaging the stud and preventing the bolt from moving until the
key is turned backward, again raising the tumblers and releasing and
retracting the bolt.


How Key Changes Are Provided.

There are three ways in which keys are made individual to the locks
they fit.

_a._ By changing the shape of the keyhole. This may be done shorter or
longer, wide or narrow, straight or tapering and with projections on
the sides which the key must fit, making it difficult or impossible
for keys of a different class to enter the lock. In the lock shown, a
projection on the keyhole will be noted, fitting a groove in the bit of
the key.

_b._ By wards attached to the lock-case. The two crescent-shaped wards
seen near the key in figure 2 illustrate this feature. Similar wards
are placed on the lock cover. These fit into the two notches shown on
the key bit in figure 4, and their shape and position are varied at
will.

_c._ By changes in the tumblers. There are five flat tumblers in the
lock shown, and their lower edges fit into the end of the key bit.
By varying their height, changes in the cutting of the key are made
necessary.

The security of a lock depends very largely upon its being so made that
no key will operate it except the one which belongs to it, and this
is obtained by guarding the keyhole by means of _a_, by preventing
the wrong key from turning by means of _b_, and by still further
limitations by means of _c_.

[Illustration: HOW A CYLINDER LOCK WORKS]

[Illustration: FIGURE 1. PARTS OF CYLINDER LOCK.]

[Illustration: FIGURE 2.

FACE OF CYLINDER LOCK.]


The Cylinder Lock.

Door locks of the highest grade of security are made with a locking
cylinder, which contains tumblers in the form of miniature bolts which
make it impossible to operate the lock except with the key to which it
is fitted. This is screwed into the lock-case through the side of the
door, with the lever on the inner end engaging the end of the bolt in
the lock, so that as it is moved it either retracts or “throws” the
bolt as desired.

Figure 1 shows all the parts of a modern master-keyed lock. Figure
4 shows a broken view of the cylinder with all parts in position.
Figure 3 shows a simpler form used when the master key is not desired.
Figure 2 shows the front, the only part which is visible when the lock
is in use, with its keyway of tortuous shape which will not admit
flat-picking tools.

When the lock is assembled, the pin tumblers project through the shell,
the master cylinder and the key plug holding all parts firmly bolted or
fastened together. When the proper key is inserted, the tumblers are
raised until the “breaks” in all of them coincide with the surface of
the key plug, releasing it and permitting the key to turn it. If any
one of the five tumblers is .002 inch too high or too low, the key will
not turn; so that no key except the one made for the lock can be used.

In the master-keyed lock, the master key causes the breaks to coincide
with the outer surface of the master ring. It is thus possible to
have a master key which will fit any desired number of locks with the
individual or change keys all different from each other and from the
master key.

The balls reduce friction to such an extent that a key has been
inserted and withdrawn for a million times without affecting the
accuracy of the lock.

[Illustration: FIGURE 3.

INTERIOR OF CYLINDER LOCK WITHOUT MASTER KEY.]

[Illustration: FIGURE 4.

INTERIOR OF MASTER-KEYED CYLINDER LOCK.]




Where Does Salt Come From?


Salt is one of the things with which we come in contact with daily
perhaps more than any other. With the exception of water, probably no
one thing is used more by all civilized people than salt.

You have already learned in our talk on elements the difference between
a mere mixture of substances and a chemical compound. You remember
that when some substances are only mixed together, they do not lose
their identity. In a compound the substances are always combined in
fixed proportions and the properties of the compound are often very
different from those of the things that make it. Common salt is made of
two substances, that are not at all like salt, and are very different
from each other. One, sodium, is a soft, bluish metal, and the other is
chlorine, a yellowish-green gas. The chemical name for salt is sodium
chloride which is derived from the two names sodium and chlorine.

Sodium and chlorine are both what we have learned to call elements. An
element being a substance which cannot be separated into substances
of different kinds. There are now known about seventy such elements.
All the substances around us are composed of these elements alone, or
chemically united in different compounds, or simply mixed together.
Most of them, however, are mixtures, not of separate elements, but of
compounds. The soil under our feet is a mixture of compounds. Water is
also a compound. Pure compounds very rarely occur naturally. Salt is
sometimes found almost pure; but generally is mixed with so many other
things that we have to take them out to get absolutely pure salt. For
practical every-day use it is unnecessary to purify the salt.

Salt is found in large quantities in the sea water, in which it is
dissolved with some other substances. It is also found in salt beds,
formed by the drying up of old lakes that have no outlets; salt wells,
that yield strong brine; and salt mines, in which it is found in hard,
solid, transparent crystals, called rock salt. Rock salt is the purest
form in which salt is found and, to prepare it for market, it is merely
necessary to grind it or cut into blocks. The greatest deposit of salt
in the world is probably that at Wielizka in Poland, where there is a
bed 500 miles long, 20 miles wide, and 1,200 feet thick. Some of the
mines there are so extensive that it is said some of the miners spend
all their lives in them, never coming to the surface of the earth.

A trip through these mines is interesting. In one of them can be seen
a church made entirely of salt. The salt supply of the United States
is obtained chiefly from the salt wells of Michigan and New York, the
Great Salt Lake in Utah, and the rock-salt mines of Louisiana and
Kansas.

In the arts and manufactures, the most important uses of salt are
in glazing earthenware, in extracting metals from their ores, in
preserving meats and hides, in fertilizing arid soil, and also, as we
shall presently see, in the manufacture of soda. Of equal importance,
perhaps, is its use in food. Most people think it not only lends a
pleasant flavor, but is itself an important article of diet. It is
certain, that all people who can obtain it use salt in their food, and
where it is scarce, it is considered one of the greatest of luxuries.

Soda is of interest to us, not so much on account of its use in
our households, as because it plays on extremely important part in
two industries that contribute greatly to our comfort, viz., the
manufacture of glass and soap.

Soda is not found naturally in great abundance, as salt is, but is
generally made from other substances. Formerly it was made almost
entirely from the ashes of certain plants. One, known as the Salsoda
soda-plant, was formerly cultivated in Spain for the soda contained
in it, and the ashes, or Barilla, as they were called, were soaked in
water to dissolve out the soda. Now, however, the world’s soda supply
is produced from common salt by two processes, known from the names of
their inventors as the Leblanc and Solvay processes.

~WHERE WE GET SODA~

In the Leblanc process the first step is to treat the salt, or sodium
chloride, with sulphuric acid. As a result of this, a compound of
sodium, sulphur, and oxygen, called sodium sulphate is formed, together
with another acid containing hydrogen and chlorine, and called
hydrochloric acid. This acid is driven off by boiling, and the sodium
sulphate is left.

The next step in the process is to convert the sodium sulphate, or
“salt cake,” into soda, or, to give it its chemical name, sodium
carbonate. This change is brought about by mixing the salt cake with
limestone and coal and heating the mixture. Just what changes go on
when this is done, are not known, but the chief ones are probably the
following: the coal, which consists for the most part of an element
called carbon, takes the oxygen out of the sodium sulphate, and unites
with it to form carbonic acid gas, leaving a compound of sodium and
sulphur called sodium sulphide; this acts on the limestone, which is
composed of a metal, calcium, in combination with carbon and oxygen,
and causes the sulphur in the sodium sulphide to combine with the
calcium, forming calcium sulphide, while the sodium combines with the
carbon and oxygen and forms the desired compound, sodium carbonate.
After the heating, the resulting mass which contains calcium sulphide,
sodium carbonate, and some unburned coal, and is known as “black
ash,” is broken up and treated with water. This dissolves the sodium
carbonate, leaving the rest undissolved, and when part of the water is
evaporated crystals containing sodium carbonate and water are formed.
By heating these the water may be driven off, and the sodium carbonate
left behind as a white powder.

The Solvay, or ammonia soda, process consists in forcing carbonic acid
gas through strong brine, to which a considerable quantity of ammonia
has been added. When this is done, crystals are formed in the brine,
which are composed of a compound of hydrogen, sodium, carbon, and
oxygen, and are called sodium bicarbonate. This substance, which is the
soda we sometimes use in baking bread, is decomposed by heating, into
water and sodium carbonate, the soda used for washing.

The Leblanc process was formerly used almost altogether for making
soda; but in recent years the Solvay process has come into extensive
use, and it is said that now more than half the soda of the world is
made in this way.




Where Do All the Little Round Stones Come From?


The little round stones you are thinking of are really pebbles which
have been worn smooth and round by being rubbed against each other in
the water, through the action of the waves on a beach, or the running
water of brooks and streams. This sort of rock is called a water-formed
rock. Some of them have travelled many miles before they are found
side by side on the shore or in a large mass of what we would call
conglomerate rock. But whenever you see a round smooth rock or pebble
you may be quite sure that it was made round and smooth by the action
of water.

You sometimes see large rocks made of small stones of various colors
and sizes. You can often find a large rock of this kind standing by
itself. If you examine it carefully, you will find it consists of an
immense number of small stones of different sizes and of a variety of
colors, all fastened together as though with cement. This kind of rock
is called conglomerate. We know two kinds of conglomerate rock, one,
quite common, in which the little stones are round and smooth, and
another, not seen so often, in which the stones are sharp. The latter
sort is sometimes called breccia, to distinguish it from the former,
which is called true pudding stone.




What Is Clay?


Clay is the result of the crumbling of a certain kind of rocks called
feldspars. When feldspar is exposed to the action of the weather, it
crumbles slowly at the surface and the little fragments combine with
a certain amount of water, forming clay. Pure clay is white and is
used in the manufacture of china and porcelain. The common clay that
we usually think of when we think of clay, is generally yellowish,
but there are many different colored clays. Most of these colors,
particularly those of red clay, yellow clay and blue clay, come from
the iron which is present in the clay. Clay which contains iron is
useful for making bricks. Bricks are made from clay by first softening
the clay and pressing it in molds, the size of a brick. When dried for
a time in the sun they are put into an oven and baked in great heat
and they become quite hard and generally red. Most of the clay from
which bricks are made turns red when baked, whether blue, yellow or
red, because the iron which is in the clay is generally turned red when
subjected to heat.

For making porcelains it is desirable to use the kinds of clay which
contain nothing that melts when heated to a high degree. Clays which
contain substances which melt in strong heat are, therefore, not good
for making porcelains. There is a pure white clay called Kaolin which
is very excellent for this purpose. Clay out of which we make firebrick
for lining stoves and fireplaces is free from substances which melt.
Several kinds of clay are good for making paints.




Where Do School Slates Come From?


Slates such as are used in school and as roofing material are formed of
clay, which has been hardened under pressure and heat. When this occurs
it does so because a number of layers of clay, one on top of the other,
have at sometime been subjected to great heat and pressure within the
earth with the result that the clay is pressed into very thick layers
and changed in color by the heat and becomes hard. There are many kinds
of slate. Some of the slate, as found in slate mines, is used to make
roofs over buildings and for this purpose they are cut to shapes very
much like wooden shingles. They are easily broken, however, as slate is
very brittle.

Slate is used in many other ways besides for roofs and school slates.
Sometimes it is made into slate pencils but, since paper has become
so cheap, comparatively few slate pencils are used in the school room
today.




What Causes Shadows?


Where anything through which rays of light cannot pass intercepts the
light rays coming from a luminous body, the light rays are turned back
in the direction from which they come and the part on the other side
of the object which intercepted the light goes into shade and a shadow
results. A shadow then is produced by cutting off one or more light
rays. We notice shadows when the sun is bright in the daytime and at
night when we walk along the streets lighted partly by street lamps.
The shadows we see in the daytime are caused by our cutting off and
throwing back some of the light rays which come from the sun. These are
not so dark as the shadows we see at night because the rays of light
from the sun are so bright and are reflected from so many other objects
to the side and in back of us.

When, however, we are walking along a dimly lighted street and come to
a street lamp the shadows our bodies cause are quite black. The night
shadows are darker because the source of light is less intense and the
objects to the side of and in back of us (if we are walking toward the
light) do not reflect so much of the light rays as they do of the sun’s
rays in the daytime.

[Illustration: DRIVING THE HOLLOW STEEL PILES TO BED ROCK.]




The Foundation of a Sky Scraper


How Hollow Steel Piles, Compressed and Concrete Are Employed to Make a
Foundation

Rapidity of building construction is of primary importance in every
city of metropolitan size. When real estate is sold at the rate of
several hundred dollars a square foot it is self-evident that time is
indeed money. The delay of a few days in completing a structure may
deprive the owner of the chance of earning thousands in rental money.
Because of the excessive depth of an open caisson, the completion of
a foundation may be delayed for months. Hence the building may not
be completed until the renting period has passed and the owner must
wait an entire year before he can expect any financial return on his
investment.

Because rapidity is so essential in city building construction the
method of first sinking an open pit to rock in providing a foundation
has been displaced to a large extent by a system in which heavy hollow
steel piles are employed in clusters to support a building. The hollow
piles are driven through quicksand to rock, cleaned out and ultimately
filled with concrete.

~PILES ARE DRIVEN DOWN TO SOLID ROCK~

In this method of constructing foundations, which is illustrated,
hollow steel piles are driven in the well-known manner down to solid
rock. The steel pile sections vary in length from 20 feet to 22 feet,
and in diameter from 12 inches to 24 inches. If the ground is to be
penetrated to a depth greater than 22 feet, the sections of piling
are connected by means of a sleeve in such manner that a watertight
joint is formed. Under a pressure of 150 pounds to the square inch a
jet of compressed air is then employed to blow out the earth and water
contained within the shell. A spouting geyser of mud rising sometimes
to a height of 150 feet, and occasional large pieces of rock blown
up from a depth of 40 feet below the ground, bear testimony to the
terrific force of the air blast.

[Illustration: THE PILES ARE ABOUT TWENTY-TWO FEET LONG. IF GREAT
DEPTHS ARE TO BE REACHED SECTIONS OF PILING ARE JOINED TOGETHER BY
MEANS OF A SLEEVE.]

When the shell has been completely cleaned out by means of the blast
of compressed air, the exposed rock can be examined by lowering an
electric light. Steel sounding rods are employed to test the hardness
of the rock and to detect the difference between soft and hard bed
rock. After the piles in each pier have been cleaned out, they must
be cut off at absolutely the same height--sometimes a very difficult
task when there is little room. The oxy-acetylene torch is used for
the purpose, the intensely hot flame cutting off the steel almost like
butter at the exact elevation desired.

[Illustration: CUTTING STEEL PILES WITH A HOT FLAME

PILE BEING CUT TO PROPER LEVEL BY MEANS OF OXY-ACETYLENE TORCH.

After the piles in each pier have been cleaned out they must be cut off
at exactly the same height--sometimes a very difficult task when there
is little room. The oxy-acetylene torch is used for the purpose, the
intensely hot flame cutting off the steel almost like butter.]

[Illustration: A CLUSTER OF PILES, CLEANED OUT, FILLED WITH CONCRETE
AND CUT OFF FLUSH BY MEANS OF THE OXY-ACETYLENE FLAME.]

~PILES ARE NEXT FILLED WITH CONCRETE~

The hollow shell is next filled with concrete reinforced by means of
long two-inch steel rods, sometimes fifty feet in length. On clusters
of these concrete-filled piles, the weight of the building is supported.

That this method of constructing foundations is indeed rapid, the
story of the work at 145-147 West Twenty-eighth Street, New York City,
proves. Rock was located 38 feet below the curb. The material above
it was clay and water-bearing sand. Structural steel was due in three
weeks, but the completion of the cellar was still ten days off. The
steel pile foundation method offered the only solution of the problem.
Specifications were drawn which called for eighty-five 12-inch steel
piles, driven to rock, blown clean by compressed air, and filled with
concrete, reinforced with 2-inch rods. Despite various obstructions on
the ground (shoring of neighboring buildings and the like) the driving
was started on June 30th. The excavator was still taking out his runway
while the rear half of the lot was completely driven. After he had left
the ground a compressor was set up, and the first pipe was blown on
July 7th. Three days later all driving and cleaning had been completed.
During the following two days all the piles were filled and capped. In
a word, the entire foundation had been completed three days before the
expected arrival of the steel.

[Illustration: CONCRETE PILES WHICH HAVE BEEN SUNK TO ROCK BOTTOM AND
IN WHICH TWO-INCH STEEL RODS HAVE BEEN INSERTED TO ACT AS REINFORCEMENT
FOR THE CONCRETE WHICH WILL EVENTUALLY BE POURED IN.]

Such rapid work is not unusual with the steel foundation method.
On another contract, work was completed not in the three months
stipulated, but in exactly one month and a half, during which brief
time all the excavation had been done, including sheeting, shoring,
pile-driving, the mounting of concrete girders to carry the wall and
capping of the piles ready to receive the grillage.

[Illustration: THE STEEL PILE IS EASILY FORCED EVEN THROUGH THE SOFT
UPPER LAYERS OF BED ROCK. SOMETIMES VERY LARGE PIECES ARE BLOWN UP INTO
THE AIR BY THE BLAST OF COMPRESSED AIR.]

Sometimes difficulties are encountered which would prove all but
insurmountable and certainly hopelessly expensive with other methods.
Thus in carrying out the one contract, water was found 12 feet from the
curb. Two running streams had intersected at that point. The piles were
simply sunk through the stream to rock bottom without any difficulty.

The excessive cost of open-pit work has sometimes made it impossible
to build twelve or fourteen-story buildings in many sections of the
city of New York. The steel pile has, however, made steel building
construction profitable.

The carrying capacity of a steel pile is enormous. On a single 12-inch
steel pile one hundred tons can be safely maintained. Piers containing
sixteen piles have been used, and loadings up to 1300 tons are not
unusual.

Naturally the question arises: Do the steel piles deteriorate in
time? The question has been answered over and over again by the piles
themselves. After a service of fifteen years the steel foundation
piles were removed from the site of a building which now stands at the
northwest corner of Wall and Nassau streets, in New York City. They
showed practically no deterioration. The oxidation on the outside was
almost negligible.

[Illustration: BLOWING OUT MUD AND ROCK WITH COMPRESSED AIR

CLEANING OUT A HOLLOW STEEL PILE BY MEANS OF COMPRESSED AIR A GEYSER OF
MUD ALWAYS APPEARS.]

[Illustration: A DRIVEWAY ALONG THE TOP OF THE OLIVE BRIDGE DAM.]




The Story in a Glass of Water


How Does the Water Get into the Faucet?

It is easy for you boys and girls who live in the city to run into the
kitchen or bathroom when you are thirsty and by a simple turn of the
faucet tap secure a glass of cool and refreshing water, but did you
ever stop to think how many men must constantly work and how great
and perfect arrangements must be made before it is possible to supply
a great city with water to drink, to bathe in, and for cooking and
washing?

No one who has never had the experience of being in a town or city
from which the water supply has been cut off, for a day or a number of
days, can realize how necessary water is in our daily lives. We are so
used to having all the water we want at any time that we even complain
when in summer we are asked to drink water which is not iced. Drinking
ice-water is very much of a habit. In tropical countries where there is
no ice, people drink the water just as they find it, and if you were to
go there and drink the waters for a few days, you would soon find that
the water slakes your thirst even when quite warm, so it is not the ice
in the water that quenches your thirst, but the water itself, and the
ice-water is not good for you, as the doctor will tell you, because it
chills the stomach.


Where Does Our Drinking Water Come from?

The best way to find out where the water in the faucet comes from is to
follow it back to its source. Let us see. Here we are in the kitchen
and you have just had a drink of water taken from the faucet above the
sink. The faucet, you will notice, is attached to a small pipe which
is fastened to the wall back of the sink. We look under the sink and
see that the pipe goes through a hole in the floor, so we reason that
the water must come from the cellar. Let us go down cellar and see.
Yes, here is the little pipe that comes down through the floor under
the sink and we follow it along the wall toward the front of the house,
and well, well, there it goes right out through the stone foundation of
the house. So we conclude that the water comes from somewhere outside
of the house, and that the little pipe we have been following is only
a means of getting it from the outside into the house. We now mark the
place in the wall where the pipe goes through and run around to the
front of the house to see where it comes out, but we don’t see it. It
must be buried in the ground, so we get a spade and pick and begin
to dig a hole in the ground, and pretty soon we find the little pipe
pointing straight out toward the street. We keep on digging the dirt
away, and thus open a little trench from the house to the middle of
the street and when we get there after a great deal of digging we find
our little pipe attached to a larger pipe which seems to run along the
ground in the middle of the street; so we are still in the dark as to
where the water comes from, excepting that so far as our own home is
concerned we know that it gets into the house through a little pipe
which is attached to a big pipe in the middle of the street. By this
time we know we have a big job on hand.

[Illustration: HOW A BIG DAM IS BUILT

BUILDING OLIVE BRIDGE DAM TO FORM THE ASHOKAN RESERVOIR.

The great Ashokan reservoir is situated about fourteen miles west of
Kingston on the Hudson River. Its cost is $18,000,000, and it will hold
sufficient water to cover the whole of Manhattan Island to a depth of
twenty-eight feet. The water is impounded by the Olive Bridge dam,
which is built across Esopus Creek, and also by the Beaver Kill and
the Hurley dikes, which have been built across streams and gaps lying
between the hills which surround the reservoir.]

[Illustration: THE OLIVE BRIDGE DAM, 4650 FEET LONG, 200 FEET HIGH.

The dam is a masonry structure 190 feet in thickness at the base, and
23 feet thick at the top. The surface of the water when the reservoir
is full is 590 feet above tide level. The total length of the main dam
is 4560 feet, and the maximum depth of the water is 190 feet. The area
of the water surface is 12.8 square miles, and in preparing the bottom
it was necessary to remove seven villages, with a total population
of 2000. Forty miles of highway and ten bridges had to be built. In
the construction of the dam and dikes it was necessary to excavate
nearly 3,000,000 cubic yards of material, and 8,000,000 cubic yards of
embankment and nearly 1,000,000 cubic yards of masonry had to be put in
place. The maximum number of men employed on the job was 3000.]

~HOW THE PIPES RUN THROUGH THE STREET~

We are pretty tired of digging by this time, so we call in all the boys
and girls in town to help us dig so that we may see where these pipes
come from, and we have a regular digging carnival. We follow the big
pipe along our own street until we come to the corner. Here we find
that our larger street pipe is connected with a still larger pipe, so
we think we had better follow the larger pipe. We keep on digging,
getting more of the boys and girls to help, and we follow that big pipe
right out to the edge of town where we see it runs into another stone
wall which you knew all the time was the reservoir, but concerning what
it was for you were perhaps never quite clear.

Right near the place where the pipe goes in is a stairway which leads
up to the top of the wall, so the whole crowd of boys and girls climb
the steps and you are at the top of the reservoir; and there spread out
before you, you see a big lake surrounded with a stone wall and you see
where the water comes from--the reservoir--at least so you think. But
you are wrong. You really haven’t come anywhere near the source of the
supply. For soon as you walk around the broad top of the wall which
surrounds your reservoir, you meet a man who asks you what you want,
and you tell him that you have been finding out where the water in the
faucet came from, but having found out you thought you would go back
home.

The man smiles at you, but, as he is good-natured and sees you are
really trying to find out where the water comes from, he tells you that
since you have gone to all the trouble of digging up the streets to
follow the pipes, you might as well learn all about it.

He first tells you that the reservoir is not really the place where the
water comes from but only a tank, so to speak. He explains to you that
most of the faucets in the city are higher than the real source of the
water, which is out in the country miles away, and as water will not
run up hill, it is necessary to keep the city’s daily supply in some
place that is higher than the highest faucet in the city, so that it
will force its way into and fill to the very end all of the large pipes
in the streets and the small pipes which go into the houses, so that
the water will come out just as soon as you turn the faucet.

Then he takes you over to a large building near the reservoir which
you have always called the water works, but never knew exactly what
it was for. He takes you into a large room where there is a lot of
nice-looking machinery working away steadily but quietly, and tells
you that these are the great pumps which lift the water from the great
pipes which bring it from far away in the country, into the reservoir
we have just seen, from which the water runs into and fills all of the
pipes into the city.

He also tells you that in some cities it is impossible to find a place
to build a reservoir which is higher than the highest places in the
city. In such places, the pumps in the water works pump the water
direct into the city water pipes and force the water to the very end of
all the pipes and keep it there under pressure all the time.

From the pumping station he takes you down stairs in the water works
and shows you the huge pipe which brings the water to the water works
from the country. It is quite the largest pipe you ever saw. You see it
is not really an iron pipe, but built of concrete, which is quite as
good. You will be surprised to have our friend, the water-works man,
tell you that three average-sized men could stand up on each other’s
shoulders inside the great pipe.

[Illustration: HOW THE BIG PIPES ARE LAID THROUGH THE COUNTRY

OLIVE BRIDGE DAM; ESOPUS CREEK FLOWING THROUGH TEMPORARY TUNNEL.]

[Illustration: PLACING THE 9¹⁄₂ FOOT STEEL PIPES.]

[Illustration: A HUGE UNDERGROUND RIVER

The water is conducted from Ashokan reservoir as a huge, underground,
artificial river. The aqueduct is ninety-two miles in length from
Ashokan to the northern city line, and it should be explained that it
is built on a gentle grade, and that the water flows through this at
a slow and fairly constant speed. The aqueduct contains four distinct
types: the cut-and-cover, the grade tunnel, the pressure tunnel,
and the steel-pipe siphon. The cut-and-cover type, which is used on
fifty-five miles of the aqueduct, is of a horseshoe shape and measures
17 feet high by 17 feet 6 inches wide, inside measurements. It is
built of concrete, and on completion it is covered in with an earth
embankment. This type is used wherever the nature of the ground and
the elevation allow. Where the aqueduct intersects hills or mountains,
it is driven through them in tunnel at the standard grade. There are
twenty-four of these tunnels, aggregating fourteen miles in length.
They are horseshoe in shape, 17 feet high by 16 feet 4 inches wide, and
they are lined with concrete. When the line of the aqueduct encountered
deep and broad valleys, they were crossed by two methods: if suitable
rock were present, circular tunnels were driven deep within this rock
and lined with concrete. There are seven of these pressure tunnels
of a total length of seventeen miles. Their internal diameter is 14
feet, and at each end of each tunnel a vertical shaft connects the
tunnel with the grade tunnel above. If the bottom of the valley did
not offer suitable rock for a rock tunnel, or if there were other
prohibitive reasons, steel siphons were used. These are 9 feet and 11
feet in diameter. They are lined with two inches of cement mortar and
are imbedded in concrete and covered with an earth embankment. There
are fourteen of these pipe siphons of a total length of six miles. At
present one pipe suffices to carry the water. Ultimately three will be
required for each siphon.]

Our water-works man sees how earnest you are in seeing just where the
water comes from, so he proposes that we go find out. We go outside and
there is an automobile all ready to go and we jump in and the machine
starts off along quite one of the nicest roads you were ever on. Soon
you exclaim, “Why, this is the aqueduct road,” and so it is. The great
pipe through which the water comes to the city is an aqueduct and they
have built the road right over the place where the aqueduct runs. Away
we go as fast as the car can carry us, sometimes ten, or twenty or
perhaps fifty miles, according to what city you are in. The city goes
as far as it must to find a supply of pure water and plenty of it and
spends millions upon millions of dollars to make its supply of water
good and certain. Occasionally we come to a little stone house along
the way where we can go down and see the sides of the great stone pipe.
After a while, however, we find our aqueduct road comes to an abrupt
stop before another great stone wall. It is the great dam which has
been built out there in the country to form one end of a great tank
that catches and holds the waters from the creeks and rivers that flow
into it. Usually the dam is built up right across a river. They simply
build the dam strong enough to stop the river from going any further.
Then, of course, the water piles up on the other side of the dam and
occasionally this tank, which is simply another huge reservoir, gets so
full that the water flows over. It does not really overflow the top of
the dam, because underneath the top the engineers have left openings
here and there for the water to get through. If it were not for these
loopholes, so to speak, the great wall of water within the reservoir,
piled against the dam, would break down the wall no matter how well
built, by the great pressure it exerts.

[Illustration: THROUGH THIS CHAMBER THE FLOW OF WATER TO THE AQUEDUCT
IS REGULATED.]

~THE REAL SOURCE OF THE WATER~

We are now near to the real source of the water. We take a trip around
the top of the great reservoir. Around at the other end we find what
looks like a river, excepting that there isn’t any current to speak of.
It is a river, but a much deeper one than it would have been but for
the dam which has been built across it, and originally its surface was
quite far down in a valley. Sometimes man makes his water dam at one
end of a lake, which has been formed by streams flowing into a valley
which has no opening for the water to run out of. In these cases the
lake will be high up in the hills and man simply builds his dam at one
end, lets the end of his aqueduct into the bottom of the lake and the
water flows. In other cases he picks out a valley where there is no
lake at all, builds his dam and then drains the water which he finds in
small lakes higher up in the hills into the one big valley and makes a
very large lake. But the water in the lakes comes originally from the
creeks, rivers or springs which run into it, and so we will follow our
original river back into the hills. Here and there along its course we
find a little stream flowing into our river and, as we go up higher and
higher into the hills, we find our river getting smaller and smaller.
Now it is only a creek and, if we go far enough, we find its source but
the tiniest kind of a tinkling brook with the water dripping almost
noiselessly between the rocks as it makes its path down the side of
the hill. There is the source of the water in the glass you have just
enjoyed.

[Illustration: DIGGING A HOLE UNDER A RIVER

DIAMOND DRILL BORING A HORIZONTAL HOLE 1100 FEET BELOW THE HUDSON
RIVER.]

[Illustration: HUDSON RIVER SIPHON, 1100 FEET BELOW THE RIVER.

Of the many siphons constructed, by far the most interesting and
difficult is that which has been completed beneath the Hudson River.
The preliminary borings made from scows in the river showed that great
depths would have to be reached before rock sufficiently solid and
free from seams was encountered to withstand the enormous hydraulic
pressure of the water in the tunnel. After failing to reach rock by the
scow drills, two series of inclined borings were made from each shore,
one pair intercepting at about 900 feet depth and the other at about
1500 feet. Both showed satisfactory rock, and accordingly a shaft was
sunk on each shore, to a depth of approximately 1100 feet, and then a
horizontal tunnel was driven connecting the two. It is of interest to
note that because of the enormous head, which must be measured from the
flow line far above the river surface, the pressure in the horizontal
tunnel reaches over forty tons per square foot.]

[Illustration: THE HIGHEST BUILDING IN THE WORLD UPSIDE DOWN

  SHAFT 752′-0 DEEP

  WOOLWORTH BUILDING 750′ 0″ HIGH

This picture shows the depth to which the pipes which carry the water
through the city must sometimes be sunk in order that it will be
certain to remain in place. To illustrate this in connection with the
depth of the water tunnel in one place in the city of New York, our
artist has taken the liberty of turning the Woolworth Building upside
down. Even this building, which is the tallest business building in the
world, and is 792 feet high, would not penetrate the water tunnel, at
the point shown, which is at the Clinton Street shaft at the west bank
of the East River.]




What is Carbonic Acid?


It was formerly called fixed air, and is a gaseous compound of
carbon and oxygen. It is procured by the processes of combustion and
respiration, and hence is always present in the air, though in minute
quantity. Plants live upon it and absorb it into their tissues; they
abstract and assimilate its carbon, and return its oxygen to the
atmosphere in a pure condition. It is also present in spring water,
and often in quantities, so that it sparkles and effervesces; it is
also produced during the processes of putrefaction, fermentation, and
slow decay of animal and vegetable substances in presence of air. It
is largely employed by the manufacturers of aerated bread and aerated
waters. Under a pressure of about 600 pounds it liquefies, and when
allowed to escape through a small jet it rapidly evaporates and causes
intense cold, so much so as to become frozen. It does not support
burning. The gas derived from it, carbon dioxide, is invisible, and
is heavier than air by one half, and has a pungent odor and slightly
acid taste. In a pure state the gas cannot be respired, as it supports
neither respiration nor combustion. When the portion in the atmosphere
is increased to a considerable extent, as happens sometimes, it
endangers life. The familiar “rising” of bread is brought about by
carbonic acid gas escaping through and permeating the dough, making
it light and porous. In this form it is known as yeast or as baking
powder. We see its uses also in the chemical fire-engine.

In some parts of the world large quantities of carbonic acid gas are
constantly issuing from openings of the earth’s surface. Two such
places are the famous Poison Valley of Java, and the Grotto del Cane,
near Naples, in Italy. The former is a small valley about a half a mile
around and about thirty-five feet deep, in which the air is so loaded
with carbonic acid gas that animals entering it are killed in a few
minutes. Even birds that fly over the valley are overcome if they do
not rise high above it. The Grotto del Cane, or Grotto of the Dog, is
a small cavern in the crater of a volcano. A stream of carbonic acid
gas flows constantly into the grotto, but the level of the gas does not
reach the height of a man’s mouth. When the same air is breathed over
and over again, the quantity of carbonic acid in it is increased so
much, that it may become as deadly as the air in the Poison Valley.

Two other gases that may generally be found in air are ozone and
ammonia. The first is merely a form of oxygen that is produced by the
passage of lightning through the air. After severe thunderstorms, it is
said to be present, sometimes, in sufficient proportion to give to the
air a slightly pungent odor. It is more active chemically than is the
ordinary form of oxygen, and consequently has a stimulating effect upon
animals.

Ammonia, or hartshorn, as it is sometimes called, from the fact that
it was formerly obtained by distilling the horns of harts, or deer, is
almost always present in the air in small quantities. It is produced
chiefly by the decay of animal and vegetable matter, especially the
former. Though present in the air in very small quantities, it is of
much value to the plant world, because it contains nitrogen in a form
in which it can be readily absorbed by plants. All plants contain some
nitrogen, which is essential to their growth, but the greater part of
the nitrogen in the air is not in such form that it can be absorbed
by them. They must obtain their supply from the soil, which usually
contains some nitrogen in a form that may be taken up by plants, and
from the ammonia in the air. The latter is not taken directly out of
the air by the plants, but the rains falling through the air absorb the
ammonia and carry it to the soil, from which it is taken up into the
plants by their roots.

~VARIOUS GASES FOUND IN AIR~

Besides the gases that have been mentioned, there is present in the
air, at all times, a small quantity of water-vapor, which is, in many
ways as important to mankind as is the oxygen itself. The quantity
of water in the air is not always the same. As a rule, the quantity
is greater in warm air than in cold, and is less over land than over
water. Frequently the air feels damp in cold weather, and dry in hot
weather, and it is natural to suppose that there is more vapor in the
air on the damp day than on the dry one. This, however, is not always
true. There is usually more moisture in the air on a warm summer day
than on a cold day in winter, though the winter day may seem much more
moist. You will be able to understand why this is so by comparing the
air to a sponge. If we fill a sponge with water, and squeeze it gently,
a little water will be forced out of it. If we then remove the pressure
on the sponge. When the air cools, will appear dry on the surface, but
there will still be water in it, and on being squeezed harder than
before it will again become moist on the surface and more water will be
forced out of it. Now cold has an effect upon moisture-laden air very
much like that of pressure on the sponge. When the air cools, some of
the moisture is forced out of it, and the air seems damp. When it warms
again, the air seems dry, though there is still water-vapor in it. It
seems dry because it can absorb more water-vapor, just as the sponge
seems dry after you cease to squeeze it, though it still contains
water. From this we see that the air does not always seem moist when
there is much water-vapor in it, nor dry when there is only a little.
It feels moist when there is as much water-vapor present as it can
hold, and dry when it can held more than it already has. And we also
see that in hot weather the air can hold much more moisture than it can
in cold weather, so that whether the air feels dry or moist, there is
generally much more water-vapor in it in hot weather than in cold.

It is easy to see that, over water, the air naturally takes up more
moisture than over land, because there is so much more water there to
be transformed into vapor. Over the surface of seas, lakes and rivers,
water is continually being converted into vapor by the process of
evaporation, and this vapor is absorbed by the air.

Let us now consider the solid particles floating in the air, the dust
that is seen dancing in the path of a sunbeam. Whenever we examine the
air, these small particles are found, even on the tops of mountains,
and at points so high above the earth that they have been reached only
by balloons. Of course, there is very much less dust high above the
earth than near the surface, where the winds are constantly stirring
up the loose soil, and throwing into the air small particles of every
kind. In cities, where factory chimneys are continually pouring out
clouds of smoke, and the people and vehicles are constantly disturbing
the dust of the streets, the air always contains more dust than does
the air of the country.

In order that we may breathe air, the oxygen in it has been mixed with
four times as much nitrogen and argon, which must be inhaled with the
oxygen, though they have no more effect on the body than the water
you take with a strong medicine to weaken it. The oxygen, however,
has a very important effect upon the body, and if we compare the air
we exhale with that we inhale we find considerably less oxygen in
the former than in the latter. In place of the oxygen, the air has
received carbonic acid gas. It may seem very strange to say that there
is burning going on in the body, but that is very nearly what takes
place. The chief difference from coal-burning is that in the body the
process goes on so slowly that it does not make the body very hot;
but when we set fire to coal, the process is much more rapid, and a
large amount of heat is produced in a short time, so that the coal
becomes very hot. The products of breathing and of coal-burning are the
same, carbonic acid gas being the chief one. When coal is burned it
disappears, together with some of the oxygen of the air, and in their
stead we have carbonic acid gas. When a breath is taken some of the
material of the body disappears, as does some of the oxygen of the air,
and in place of them carbonic acid gas is found. If we could weigh the
coal burned and the oxygen that disappears in the burning of it, and
could then weigh the carbonic acid gas that is produced in the burning,
we should find that the latter weighs just as much as the coal and the
oxygen together. So, too, if we could weigh the oxygen that disappears
from the air we breathe, and also find the weight of the material taken
from our bodies by breathing, we should find that the two together
weigh just as much as the carbonic acid gas given off in our breath. In
neither case is anything absolutely destroyed; the substances resulting
from the change weigh just as much as those that took part in it.

Having learned that a quantity of oxygen disappears every time we
take a breath, every time we build a fire, it would seem that in the
thousands of years during which men and animals have been living on the
earth, all the oxygen would have been exhausted and nothing left in
its place but carbonic acid gas. That, however, is impossible, as the
carbonic acid gas is used up almost as fast as it is produced and the
oxygen is returned to the air in its stead.

~HOW PLANTS EAT CARBONIC ACID~

All trees and plants, from the great redwood trees of California to the
smallest flowers that dot the fields, need carbonic acid gas to keep
them alive and to make them grow. Their leaves have the power when the
sun shines on them to take up carbonic acid from the air and to return
oxygen in exchange. In this way you see that the balance is kept just
as it should be. The oxygen needed by animals of all kinds is furnished
by the plants, and the carbonic acid required by plants is thrown off
in the breath of animals.




Is It a Fact that the Sun Revolves On Its Axis?


It is a proved fact that the sun revolves on its axis. All parts of its
surface, however, do not rotate with the same velocity. The rotation of
the sun differs from that of the earth in this respect.

This constitutes the visible proof that the physical state of the sun
is different from the earth’s, although they are composed of similar
chemical elements.

The earth, being covered with a solid crust, and being also, as recent
investigation demonstrates, as rigid as steel throughout its entire
globe, rotates with one and the same angular velocity from the equator
to the poles.

If you stood on the earth’s equator you would be carried by its daily
rotation round a circle about 25,000 miles in circumference. If you
stood within a yard of the North or South Pole you would be carried, by
the same motion, round a circle not quite 19 feet in circumference. And
yet it would require precisely the same time, viz., twenty-four hours,
to describe the 19-foot circle as the 25,000-mile one.




What Is the Most Usefully Valuable Metal?


If you were guessing you would naturally say that gold is, of course,
the most valuable of the metals. But you would be wrong. The proper
answer to this is iron. We do not mean the pound for pound value, for
you could get much more money for a pound of gold than for a pound
of iron, but we mean in useful value--iron is in that sense the most
valuable metal known to man. This is so because iron is of great
service to man in so many different ways, and it is very well that
there is so great a quantity of it for man’s use.

[Illustration: WHERE DOES TOBACCO COME FROM?

GROWING TOBACCO UNDER CHEESECLOTH.]




The Story in a Pipe and Cigar[6]

  [6] Copyright by Tobacco Leaf Publishing Co.


Where Did the Name Tobacco Originate?

It is now generally agreed that the word tobacco is derived from
“tobago,” which was an Indian pipe. The tobago was Y-shaped, and
usually consisted of a hollow, forked reed, the two prongs of which
were fitted into the nostrils, the smoke being drawn from tobacco
placed in the end of the stem. The island of Tobago, contrary to the
belief of many, did not furnish the name for tobacco, but on the other
hand, it was given that name by Columbus, owing to its resemblance in
shape to the Indian pipe.


How Was Tobacco Discovered?

While tobacco is now found growing in all inhabited countries, it is a
native of the Americas and adjacent islands. Its discovery by civilized
man was coincident with the discovery of this continent by Christopher
Columbus in 1492. Columbus and his adventurous sailors found the
native Indians using the weed on the explorer’s first visit to the new
world. Investigation has established that the plant was first used
as a religious rite and gradually became a social habit among the
natives. Columbus and his Castilian successors carried the weed to
Spain. Sir Walter Raleigh took it to England, Jean Nicot, whose name
is immortalized in nicotine, introduced it to the French; adventurous
traders brought the seed to Turkey and Syria, and Spanish argosies
carried it westward from Mexico to the Philippines and thence to China
and Japan. Thus within two centuries after its discovery tobacco was
being cultivated in nearly every country and was being used by every
race of men.


Where Does Tobacco Grow?

While tobacco is a native of the Americas, it is a fact that it will
grow after a fashion almost anywhere. Milton Whitney, Chief of the
Division of Soils, United States Department of Agriculture, in his
bulletin on tobacco soils says tobacco can be grown in nearly all
parts of the country even where wheat and corn cannot economically
be grown. The plant readily adapts itself to the great range of
climatic conditions, will grow on nearly all kinds of soil and has
a comparatively short season of growth. But while it can be so
universally grown, the flavor and quality of the leaf are greatly
influenced by the conditions of climate and soil. The industry has
been very highly specialized and there is only demand now for tobacco
possessing certain qualities adapted to certain specific purposes....
It is a curious and interesting fact that tobacco suitable for our
domestic cigars, is raised in Sumatra, Cuba and Florida, and then
passing over our middle tobacco States the cigar type is found again
in Massachusetts, Connecticut, Pennsylvania, Ohio and Wisconsin....
It is surprising to find so little difference in the meteorological
record for these several places during the crop season. There does not
seem to be sufficient difference to explain the distribution of the
different classes of tobacco, and yet this distribution is probably
due mainly to climatic conditions.... The plant is far more sensitive
to these meteorological conditions than are our instruments. Even in
such a famous tobacco region as Cuba, tobacco of good quality cannot
be grown in the immediate vicinity of the ocean or in certain parts
of the island that would otherwise be considered good tobacco lands.
This has been experienced also in Sumatra and in our own country, but
the influences are too subtle to be detected by our meteorological
instruments.... Under good climatic conditions, the class and type
of tobacco depend upon the character of the soil, especially on the
physical character of the soil upon which it is grown, while the grade
is dependent largely upon the cultivation and curing of the crop.
Different types of tobacco are grown on widely different soils all the
way from the coarse sandy lands of the Pine Barrens, to the heavy,
clay, limestone, corn and wheat lands. The best soil for one kind of
tobacco, therefore, may be almost worthless for the staple agricultural
crops, while the best for another type of tobacco may be the richest
and most productive soil of any that we have.

~WHERE HAVANA TOBACCO IS GROWN~

Havana tobacco, which means all tobacco grown on the island of Cuba,
possesses peculiar qualities which make it the finest tobacco in the
world for cigar purposes. The island produces from 350,000 to 500,000
bales annually, of which 150,000 to 250,000 bales come to the United
States for use in American cigar factories. The best quality of the
Cuban tobacco comes largely from the Vuelta Abajo section, although
some very choice tobaccos are raised also in the Partidos section.
Remedios tobaccos are more heavily bodied than others and are used
almost exclusively for blending with our domestic tobaccos. While there
are innumerable sub-classifications, such as Semi-Vueltas, Remates,
Tumbadero, etc., the three general divisions named above, Vuelta
Abajo, Partidos and Remedios, embrace the entire island. If a fourth
general classification were to be added, it would be Semi-Vueltas.
The Vuelta Abajo is grown in the Province of Pinar del Rio, located
at the western end of the island. It is raised practically throughout
the entire province. Semi-Vueltas are also grown in Pinar del Rio, but
the trade draws a line between them and the genuine Vueltas. Partidos
tobacco, which is grown principally in the Province of Havana, differs
from the Vuelta Abajo in that it is of a much lighter quality. The
Partidos country is famous for its production of fine light glossy
wrappers. Tobacco from the foregoing sections is used principally in
the manufacture of clear Havana cigars. Some of the heavier Vueltas,
however, are also used for seed and Havana cigar purposes. Remedios,
otherwise known as Vuelta-Arriba, is grown in the Province of Santa
Clara, located in the center of the island. This tobacco is taken
almost entirely by the United States and Europe and is used here for
filler purposes, principally in seed and Havana cigars. Its general
characteristics are a high flavor and rather heavy body, which make it
especially suitable for blending with our domestic tobaccos. Havana
tobacco is packed and marketed in bales.


Preparing the Seed Beds.

The first step is the preparation of the seed beds. For these beds
low, rich, hardwood lands are selected. The trees are cut down and the
wood split, converted into cord wood and piled up to dry. About the
middle of January this wood is stacked up on skid poles and ignited.
The ground is thus cleared by burning, the fires being moved from spot
to spot until a sufficient area is cleared. By this process all grass,
weeds, brush and insects are eradicated. The ground is then dug up with
hoes and cleared off and a perfect seed bed is made.

The tobacco seed is first mixed with dry ashes in the proportion of
about a tablespoonful of seed to a gallon of the ashes, and about this
quantity is sowed over a square rod of land. This amount is calculated
to supply plants enough for one acre of ground, but the farmers usually
double the planting as a precaution against emergencies. After the seed
beds are sowed they are covered over with cheesecloth as a means of
protection, and they are carefully weeded and watered until the leaves
have attained a length of about four inches. They are then ready for
transplanting, which operation begins about the middle of April.


Fertilization.

In the meantime, the tobacco-growing areas have been prepared by
plowing and fertilizing. The matter of fertilization has been the
subject of much study and many experiments, and it has been definitely
established that cow manure is one of the best for this purpose.
This natural fertilizer is distributed on the fields at the rate of
ten to twenty two-horse loads to each acre. In addition to this from
two hundred to three hundred pounds of carbonate of potash, and from
two thousand to three thousand pounds of bright cottonseed meal are
employed. The total cost of this fertilizer amounts to about $120 per
acre.


Planting.

After the fertilizer is well plowed into the land the ground is laid
off into ridges about four feet apart, made by throwing two one-horse
furrows together. These ridges are about two feet in width and are
flattened on the top so as to make a level bed for the young plant. The
farmer then measures off and marks these rows at intervals of 16 to 18
inches. At each mark he makes a small hole, and after pouring in a pint
of water the plant is carefully set. Machine planters are used for this
purpose to a limited extent.


Care of the Growing Crop.

The growers usually calculate on finishing their planting about the
first of June. The young plants are then closely watched and are hoed
and cultivated at least once a week. They are also supplied with
sufficient water to keep them alive and growing. At this stage of the
proceedings, the planter begins to look out for worms. The butter worm
is one of his greatest enemies. This is a small green moth that lays
its eggs in the bud of the plant and turns into a worm two days later.
To stop the ravages of this insect, it is customary to use a mixture
composed of some insecticide mixed with corn meal. A small pinch of
this mixture is inserted at regular intervals in the bud of each plant
until the plant is nearly grown.

When the tobacco is about three feet high, all such leaves as were on
the plant when it was first set out are picked off and thrown away.
About this time the crop is usually threatened by another enemy known
as the horn worm. This is a large, mouse-colored moth, which swarms
over the field about sun-down, and deposits green eggs about the size
of a very small bird shot, on the back sides of the leaves. This is a
very ravenous insect and unless carefully watched it will devour every
leaf of tobacco, leaving nothing but the stalks standing. It is removed
by picking off and by insecticides.

[Illustration: A FIELD OF FINE HAVANA.]


Harvesting.

About sixty to ninety days after setting, the bottom leaves on the
plant are ripe and the grower is able to remove from three to four
on each stalk. This is called priming. The primer detaches each leaf
carefully and places it face down in his left hand, inspecting it at
the same time to see that no worms are carried to the barns. Upon
accumulating a handful, he places them in baskets that are lined with
burlap to prevent injury to the leaf, and the filled baskets are either
carried or hauled to the barns.

About this time the plants have begun to bud out at the top, and
this bud, with a few small leaves around it, is broken off. This
process is called topping, and is done for the purpose of confining
the development of the plant to the leaves below. After topping, the
priming of the tobacco is continued for about three weeks, and until
all the upper leaves of marketable value have been harvested. In the
meantime, the suckering has to be looked after, which is the removing
of the small branches that have a tendency to grow out of the main
stalk of the plant.

In the barns the leaves are placed on long tables, behind which stand
the stringers. They string the leaves, each separately, on strong
cotton twine, about thirty leaves to a string, spaced about an inch
apart. If this is not done carefully and accurately, several leaves may
become bunched together and the cure will thereby be impaired. It is
attention to this detail which prevents the defect known as pole-sweat.
These strings are tied at either end to a tobacco lath, and the lath is
hung upon two poles. These poles are placed in courses in the barn, at
spaces of two feet, one above the other.

[Illustration: A MODERN CUBAN TOBACCO PLANTATION.]

~HOW TOBACCO IS CURED~

Here the tobacco undergoes its preliminary, or barn cure, and during
this period the grower is constantly on the anxious seat, having to
open and close his curing houses according to the changes in the
weather, and to look closely after the ventilation of his crop in order
to avoid the development of stem rot and other afflictions with which
the tobacco is threatened at this stage of the proceedings.

[Illustration: A STAND OF TOBACCO IN EACH HAND.]


Bulk Sweating.

In due course of time the laths are taken down, the strings removed and
the leaves are formed into hands and tied with a string. The tobacco is
then packed temporarily in cases and delivered at the fermenting house,
where it is put into what is known as the bulk sweat. This consists
of uniform piles of tobacco covered over with blankets, and which are
frequently “turned” in order that they shall cure evenly and not become
too dark in color. From the bulk sweat the tobacco goes to the sorting
tables, where it is divided into numerous grades of length and color.
It is then turned over to the packers, who form it into bales.


How is Tobacco Cultivated?

As the young plants spring up and begin to grow, they are thinned out,
watered and cared for until along in October or November, and as soon
as the weather becomes settled for the season, the little seedlings
are transplanted into the field. Some growers use shade, but most of
the tobacco is grown in the open. The plants are placed in rows, very
much as corn is planted, only farther apart. The plants are carefully
protected from weeds and insects, and in December the early tobacco is
ready to be harvested. Here the mode of procedure differs according
to the discretion of the grower. The plan universally in vogue until
recent years was to cut the plant down at the base of the stalk.
Lately, however, the more scientific growers harvest their tobacco
gradually, picking it leaf by leaf, according as they ripen and mature.
The tobacco is then allowed to lie in the field until the leaves are
wilted. The stalks (or stems, according to the method followed) are
then strung on _cujes_ or poles, so that the plants hang with the tips
down. The tobacco is then allowed to hang in the sun until it is dry
and later carried into the barns, where the poles are suspended in
tiers until the barn is full. Tobacco barns everywhere are constructed
with movable, or rather, adjustable, side and end walls which permit of
a constant adjustment of the ventilation. While hanging in the barn the
tobacco undergoes its preliminary cure and changes in color from the
green of the growing plant to a yellowish brown. The climatic changes
have to be carefully studied during this process. If the weather is
extremely dry it is customary to keep the barns closed in the daytime
and to open the ventilators at night. It is generally desirable to
keep the tobacco fairly dry while it is undergoing the barn cure. After
a few weeks, and when the hanging tobacco has reached the proper stage
of maturity, a period of damp weather is looked for so that the dry
leaves may be rehandled without injury. When the desired shower comes
along the tobacco is stripped off the poles and placed in _pilon_--that
is, in heaps, or piles, on the floors of the barns and warehouses, each
pile being covered with blankets. Here, being in a compact mass, it
undergoes the _calentura_, or fever, by which it is pretty thoroughly
cured, the color changing to a deeper brown. After about two weeks in
the piles it is sorted, tied into small bundles or carrots, and these
in turn are packed in bales. After being baled the tobacco, if allowed
to remain undisturbed, undergoes a third cure, by which it is greatly
improved in quality. It is then ready for the factory.

[Illustration: A TOBACCO BARN.]


The Shade-growing Method.

The shade-growing method is one of the institutions of modern tobacco
cultivation. The principle is this: The sun, shining on the tobacco
plants, draws the nutrition from the earth, and the plant ripens
quickly, the leaves having a tendency to be heavy-bodied and not very
large. To defeat these results and produce large, thin, silky leaves
for cigar-wrapper purposes, the grower sometimes covers his field with
a tent of cheesecloth or with a lattice-work of lathing which protects
the growing tobacco from the direct rays of the sun. Thus the ripening
process is slower, causing the leaves to grow larger and thinner and
less gummy; and being thinner and less gummy, they are of a lighter
color when finally cured. This method is employed by some growers in
cigar-leaf districts, such as Cuba, Florida and Connecticut.

[Illustration: TAKING TOBACCO FROM BALES]


How Are Cigars Made?

While many labor-saving devices have been introduced in all branches
of tobacco manufacture, it is a curious fact that in the production
of the best grade of cigars, namely, the clear Havana, the work is
done entirely by hand. In fact, it may be said that in the process of
manufacturing fine cigars exactly the same principles are followed
as those of two centuries ago. There has been much improvement in
the artisanship of the worker, of course, but no rudimentary change
in method. In the manufacture of snuff, chewing and pipe tobacco,
cigarettes and all-tobacco cigarettes, machinery plays an important
part; and mechanical devices are also used extensively in the
production of five-cent cigars and in the still higher priced grades
of part-domestic cigars, such as the seed and Havana. Some of these
appliances are almost human in their ingenuity. But in fashioning the
tobacco of Cuba into cigars that are perfect in shape, in formation
and in all the qualities that go to make a good cigar, there is no
substitute for the human hand.

Upon opening a bale of tobacco the workman takes each carrot out
separately, shakes it gently to separate the leaves, and then moistens
it, either by dipping it into a tub of water from which it is quickly
removed and shaken to throw off the surplus water or else by spraying
it with a blower. It is left in this condition over night, so that the
leaves may absorb the moisture and become uniformly damp and pliable.

The tobacco is then turned over to the strippers, who remove the midrib
from each leaf, at the same time separating the wrapper from the
filler. From this point on the treatment of the wrappers and fillers is
different.

The half leaves suitable for fillers are spread out and placed one
on top of the other, making what are called books. These books are
placed side by side, closely together, on a board, and a similar board
is placed on top of the tobacco to hold it in position. Later, it is
packed into barrels, the tops of which are covered with burlap, and
there it undergoes a fermentation. It is usually allowed to remain in
this condition for ten days or two weeks, when it is rehandled and
inspected, and if found to be in the right condition, it is placed on
racks, where it remains until it is in just the proper state of dryness
to be ready for working.

~THE GREAT CARE NECESSARY IN SELECTION~

The wrapper leaves, after leaving the hands of the stripper, are taken
by the wrapper selector, who sits, usually, at a barrel, and spreads
out each leaf, one on top of the other, over the edge of the barrel,
assorting them as to size, color, etc., into several different piles or
books. Each of these piles is divided into packs of twenty-five each,
and each lot of twenty-five is folded over into what is called a “pad”
and tied with a stem. It is in this form that they go to the cigarmaker.

Every morning the stock is distributed among the cigarmakers. Each
workman is given enough tobacco to make a certain number of cigars,
and when his work is finished he must return either the full number of
cigars or the equivalent in unused leaves.

The tools of the cigarmaker consist merely of a square piece of
hardwood board, a knife and a pot of gum tragacanth. He sits at a
table upon which rests the board, and at which there is also a gauge
on which the different lengths are indicated. Fastened to the front
of each table is a sack or pocket of burlap into which the cuttings
that accumulate on the table are brushed. The operator deftly cuts his
wrapper from the leaf, fashions the filler into proper form and size
in the palm of his hand (this is known as the “bunch”) and rolls the
tobacco into cigar form, In winding the wrapper around the “bunch” the
operator begins at the “lighting end” of the cigar, called the “tuck,”
and finishes at the end that goes into the mouth, which is called the
“head.” A bit of gum tragacanth is used to fasten the leaf securely at
the “head.” The cigar is then held to the gauge and is trimmed smoothly
off to the proper length by a stroke of the knife at the “tuck.” The
cigars are taken up in bundles of fifty each. They next pass into
the hands of the selectors, who separate them into different piles,
according to the color of the wrappers, and who also reject any cigars
that may be of faulty construction. Broken wrappers, bad colors or any
other defects are sufficient to cause the rejection of a cigar. The
rejected cigars are known as _resagos_ (“throwouts”) or _secundos_.

From the selectors the cigars go to the packers, whose duty it is to
place them in the boxes, and to see that the colors in each box are
uniform, marking the temporary color classification on each box in lead
pencil. After being packed, the filled boxes are put into a press and
so left for twelve hours or until the cigars conform somewhat to the
shape of the box which contains them. On being removed from the press,
if to be banded, the cigars are carefully removed in layers from the
box, the bands affixed, and the cigars replaced. The goods are then
placed in an air-tight vault to await shipment.

When the cigarmaker ties up his bundle of fifty cigars, he attaches to
it a slip of paper upon which is marked his number. This enables the
manufacturer to keep an accurate account of the number of cigars made
by each workman and also to place the responsibility for any defects in
the workmanship. Cigarmakers are paid by the piece, the scale of wages
ranging from $16 to $100 per thousand. In nearly every factory there
may be found advanced apprentices or old men working at the rate of
$14 per thousand and also there may be found skilled artisans making
exceptionally large odd sizes at more than $100 per thousand, but these
are not generally considered in the regulation scale of prices. In
averages, the workmen earn about $18 a week and make about 150 cigars a
day.


Just a Few Figures About Tobacco.

The internal revenue from tobacco for one year would build fourteen
battleships of the first-class; or it would pay the salary of the
President of the United States for nearly a thousand years. It would
pay the interest on the public debt for three years, and there would be
enough left over to add a dollar to the account of every savings bank
depositor in the United States.

The money spent by smokers for cigars only, _not counting_ cigarettes,
smoking and chewing tobacco and snuff would more than pay for the
building of the Panama Canal, besides taking care of the $50,000,000
paid to the new French Canal Co., and the Republic of Panama for
property and franchises. And in addition to this it would cover the
cost of fortifying the Canal.

Or it would build a fleet of thirty-five trans-Atlantic liners, each
exactly like the lost _Titanic_, coal them, provision them and keep
them running between New York and Liverpool with a full complement of
passengers and crew, almost indefinitely.

There are 21,718,448 cigars burned up in the United States every
twenty-four hours; and 904,935 every hour; and 15,082 every minute; and
251 _every second_.

The annual _per capita_ consumption of cigars in the United States,
counting men, women and children, is eighty-six cigars.

_If all the cigars smoked in the United States in one year were put
together, end to end, they would girdle the earth, at its largest
circumference, twenty-two times._

AS TO THE CIGARETTES, there are 23,736,190 of them consumed in the
United States every day; and 989,007 every hour; and 16,482 every
minute. With every tick of your watch, night and day, the year around,
the butts of 275 smoked-up cigarettes are dropped into the ash tray.

Cigarette smokers in the United States, not counting those who roll
their own smokes from tobacco, spend $60,645,966.36 for the little
paper-covered rolls.

If all the cigarettes smoked in the United States in one year were
placed end to end and stood up vertically they would make a slender
shaft rising 512,766 miles into the heavens.

_If strung on a wire they would make a cable that would reach from
the earth to the moon and back again, with enough left over to circle
one-and-a-half times around the globe._

If this quantity of tobacco could be placed on one side of a huge
balancing scale it would take the combined weight of four vast armies,
each army consisting of 1,000,000 men, to pull down the other side of
the scale.

The weight of the tobacco consumed in the United States in a year is
equal to the weight of the entire and combined population of Delaware,
Maryland, West Virginia, North Carolina, South Carolina, Georgia,
Florida, Tennessee and Alabama.

[Illustration: HOW OUR FINGER PRINTS IDENTIFY US

ARCH: IN THIS PATTERN RIDGES RUN FROM ONE SIDE TO ANOTHER, MAKING NO
BACKWARD TURN.]

[Illustration: LOOP: SOME RIDGES IN THIS PATTERN MAKE A BACKWARD TURN,
BUT WITHOUT TWIST.]




The Story in a Finger Print[7]

  [7] Engravings and story by the courtesy of Scientific American.


Our Fingers.

One of the most interesting facts about our fingers is that every
member of the human race, irrespective of age or sex, carries in
person certain delicate markings by which identity can be readily
established. If the inner surface of the hand be examined, a number
of very fine ridges will be seen running in definite directions, and
arranged in patterns, there being four primary types--arches, loops,
whorls, and composites. It has been demonstrated that these patterns
persist in all their details throughout the whole period of human life.
The impressions of the fingers of a new-born infant are distinctly
traceable on the fingers of the same person in old age. The fact that
these patterns on the bulbs of the fingers are characteristic of and
differentiate one individual from another, makes it an ideal means of
fixing identity. Even men who look so much alike that it is virtually
impossible to tell one from the other so far as facial characteristics
are concerned, can be identified by their finger impressions.

Innumerable illustrations can be given of how the perpetrators of
crime have been identified and convicted by their finger prints.
Impressions left by criminals on such articles as plated goods, window
panes, drinking glasses, painted wood, bottles, cash boxes, candles,
etc., have often successfully supplied the clue which has led to the
apprehension of the thief or thieves. One of our illustrations is that
of a champagne bottle which was found empty on the dining-room table
of a house which had been entered by a burglar in Birmingham, England.
There was a distinct impression of a thumb mark on the bottle. An
officer of the Birmingham City Police took the bottle to New Scotland
Yard, London, and within a few minutes a duplicate print was found in
the records. The burglar was arrested the same evening.

[Illustration: FINGER PRINTS OF DIFFERENT PEOPLE ARE DIFFERENT

WHORL: RIDGES HERE MAKE A TURN THROUGH AT LEAST ONE COMPLETE CIRCUIT.]

[Illustration: COMPOSITE: INCLUDES PATTERNS IN WHICH TWO OR MORE OF THE
OTHER TYPES ARE COMBINED.]

Many similar instances could be given of how thieves have been caught
by handling bottles and glasses. On one occasion a burglar entered a
house in the West End of London, and before leaving helped himself
to a glass of wine. On the tumbler used he left two finger imprints,
and these were subsequently found, upon search in the records at New
Scotland Yard, to be identical with two impressions of a notorious
criminal, who was in due course arrested and sentenced to four years’
imprisonment.

A somewhat gruesome relic is a cash-box which bears the blurred thumb
mark of a man who was convicted of murder. The box was found in the
bedroom of a man and his wife who were murdered at Deptford, London, in
1905. The cash-box was taken to New Scotland Yard, and the impression
photographed and enlarged. Two brothers, suspected of the crime, were
arrested, and the thumb print of one was found to be identical with
that on the lid of the box. Our photograph of a gate recalls a curious
case that recently occupied the attention of a London magistrate. In
this instance a thief successfully climbed the gate, which was ten feet
high. In his attempt to reach the ground on the inner side he placed
his feet on the center cross-bar, at the same time holding the spikes
with his right hand. In this position he fell, and the ring he wore on
his little finger caught on the spike indicated by the arrowhead. This
caused him to remain suspended in the air until his weight tore the
finger from his hand. The ring with the finger was found on the spike,
and in due course was received at New Scotland Yard. An impression was
taken of the finger, and search among the records revealed a duplicate
print, which led to the man’s arrest.

If a criminal handles a piece of candle or removes a pane of glass and
leaves these behind, it is a hundred to one he has left a valuable
clue for the police. The candle shown on the following page bears the
imprint of a man’s thumb, and was found in a house which a burglar had
entered. By handling the candle, the thief virtually signed the warrant
for his own arrest.

The system was first used by the police in the Province of Bengal,
India, at the instigation of Sir William Herschel. Its value was at
once apparent. The work of the courts was considerably lightened,
as the natives recognized that a system of identification had been
discovered which was indisputable. Then from the police it was
introduced into various branches of the public service, and here again
its value was quickly demonstrated. When native pensioners died, for
instance, friends and relatives personated them, and so continued to
draw their allowances. By recording the identity of pensioners by
finger prints, this evil was quickly stamped out.

[Illustration: IMPRESSIONS MADE BY THE FINGERS AND PALMS

PALMARY IMPRESSIONS OF WHOLE HAND, SHOWING HOW IT IS COVERED WITH
RIDGES AND PATTERNS.]

[Illustration:

                 RIGHT HAND  LEFT HAND
  THUMB
  FIRST FINGER
  SECOND FINGER
  THIRD FINGER
  FOURTH FINGER

FINGER IMPRESSIONS OF AN ORANG-OUTANG (ANTHROPOID APE) TAKEN AT THE
LONDON ZOO. THEY WERE MADE BY SCOTLAND YARD.]

The wonderful lineations, in the form of ridges and patterns, which
adorn the palmar surface of the human hand, had, of course, been
known for many years. Mr. Francis Galton, the famous traveler and
scientist, was perhaps the first to give serious attention to the
subject of finger prints. He discovered many interesting facts about
them. Then, in 1823, Prof. Purkinje, of Breslau, read a paper before
the University of Breslau on the subject. Up to this date, however, no
practical use could be made of the impressions for the want of a system
of classification. Prof. Purkinje certainly suggested one, but little
notice appears to have been taken of it.

Naturally, to be of any value to the police or to any government
department, it is absolutely essential to classify the prints in such
a way that they could be readily referred to and identity established
without undue delay. It was virtually left to Sir William Herschel,
of the Indian Civil Service, to invent a really practical system of
classification, so it may be claimed that the finger-print method
of identification, as at present adopted, is the discovery of an
Englishman. Then it is only fair to add that Sir Edward R. Henry, the
Commissioner of the Metropolitan Police of London, has also devoted
much time and study to the subject. His book, “Classification and Uses
of Finger Prints,” has passed through many editions, and has been
translated into several foreign languages.

[Illustration: HOW THIEVES HAVE BEEN CAUGHT THROUGH FINGER PRINTS

A CHAMPAGNE BOTTLE HAVING THUMB IMPRINT, WHICH LED TO ARREST OF A
BURGLAR.]

[Illustration: CANDLE BEARING THUMB MARK OF A BURGLAR.]

[Illustration: CASH-BOX IN BEDROOM OF MURDERED MAN AND WIFE. THE THUMB
IMPRESSION (POINTED AT BY ARROW) LED TO ARREST OF THE MURDERER.]

Impressions are divided up into four distinct types or patterns. First,
we have arches in which the ridges run from one side to the other,
making no backward turn. In loops, however, some of the ridges do make
a backward turn, but are devoid of twists. In whorls some of the ridges
make a turn through at least one complete circuit. Under composites are
included patterns in which two or more of the former types are combined
in the same imprint. Although similarity in type is of frequent
occurrence, completely coincident ridge characteristics have never been
found in any two impressions. It is not necessary here to enter into
a detailed account as to how the classification of these wonderful
lineations of the human hand is effected. It is based on a number
value, attained by an examination, by means of a magnifying glass, of
the “deltas” and “cores,” which break up a collection into as many as
1024 separate primary groups, each of which can again, by a system
of sub-classification, be further split up into quite a number of
sub-groups. When the British police discover finger prints on articles
at the scene of crime, the latter are at once conveyed to New Scotland
Yard. If the impressions are very faint, a little powder, known to
chemists as “grey powder” (mercury and chalk), is sprinkled over the
marking and then gently brushed off with a camel-hair brush. This
brings out the imprint much more clearly. If one places his dry thumb
upon a piece of white paper no visible impression is left. If powder,
however, is sprinkled over the spot and then brushed off, a distinct
impression is seen. In the case of candles and articles of this nature,
a drop of printer’s ink is lightly smeared over an impression, in order
the more clearly to define the ridges and patterns.

[Illustration: A SPIKE THAT CAUGHT A CRIMINAL

ON THE SPIKE OF THE GATE (INDICATED BY AN ARROW) A CRIMINAL LEFT HIS
FINGER AND RING, WHICH LED TO HIS CONVICTION.]

At the headquarters of the British police at New Scotland Yard they
possess special cameras and a dark room for photographing these thumb
marks. The dark room is 21 feet long and 7 feet wide. When finger
prints are required for production in court they are first enlarged
five diameters with an enlarging camera. The negatives are afterward
placed in an electric light enlarging lantern, with which it is
possible to obtain photographic enlargements of a thumb mark 36 inches
square. The lantern is arranged on a specially made table 12 feet long,
the lantern running between tram lines, so that when moved it is square
with the easel.

Criminals have naturally come to dread the value of their thumb marks
as a means of identifying their movements. Some will try to obliterate
the markings by pricking their fingers, but so far this has not
availed them. To successfully accomplish this it would be necessary
to obliterate the whole of the palmary impressions on the tip of each
finger of each hand.

Then the system, too, is far in advance of any other, both in
reliability and simplicity of working. Compared to anthropometry, for
instance, invented by M. Bertillon, in which measurements of certain
portions of the body are relied upon as a medium of identification, the
finger-print system is certainly preferable. In the first place, the
instruments are costly and are liable to get out of order; while the
measurements can only be taken by a fairly educated person, and then
only after a special course of instruction. In the finger-print system
the accessories needed are a piece of paper and ink, while any person,
whether educated or not, after half an hour’s practice, can take
legible finger prints. Then the classification of the latter is much
simpler and readier of access than the former.

At the time of writing there are some 164,000 finger-print records in
the pigeon-holes at New Scotland Yard, and the number now being added
to it is at the rate of about 250 weekly. The system, too, is not only
in use in Great Britain, but in all the provinces of India, including
Burma, and in most of the British colonies and dependencies. It is
being rapidly extended, not only throughout Europe, but also through
North and South America.

[Illustration: RECORDS OF FINGER PRINTS ARE KEPT AT HEADQUARTERS

  SPECIMEN FORM.

  This Form is not to be pinned.

  MALE.

  H.C.R. No. .....

  Name .....

  Aliases .....

  Classification No.

  28. MM.
  32. II.

  RIGHT HAND.
   1.—Right Thumb.
   2.—R. Fore Finger.
   3.—R. Middle Finger.
   4.—R. Ring Finger.
   5.—R. Little Finger.

  (Fold.)

  (Fold.)

  Impressions to be so taken that the flexure of the last joint shall
  be immediately above the black line marked (Fold). If the impression
  of any digit be defective a second print may be taken in the vacant
  space above it.

  When a finger is missing or so injured that the impression cannot be
  obtained, or is deformed and yields a bad print, the fact should be
  noted under Remarks.

  LEFT HAND.
   6.—L. Thumb.
   7.—L. Fore Finger.
   8.—L. Middle Finger.
   9.—L. Ring Finger.
  10.—L. Little Finger.

  (Fold.)

  (Fold.)

  LEFT HAND.

  Plain impressions of the four fingers taken simultaneously.

  RIGHT HAND.

  Plain impressions of the four fingers taken simultaneously.

  Impressions taken by

  Classified at H.C. Registry by

  Tested at H.C. Registry by

  13336

  Rank

  Police }
  Force. }

  Date

  Date

  (P.T.O.)]

[Illustration: COMBS OF HONEY AS WE RECEIVE SAME]




The Story in a Honey Bee[8]

  [8] Pictures by Courtesy of E. R. Root Co.


Of all the insect associations there are none that have more excited
the admiration of men of every age or that have been more universally
interesting than the colonies of the common honey-bee.

The ancients held many absurd views concerning the generation and
propagation of bees, believing that they arose from decaying animals,
from the flowers of certain plants, and other views equally ridiculous
from our present point of view.


Where Does Honey Come From?

Honey is a sticky fluid collected from flowers by several kinds of
insects, particularly the honey bee; and the common honey bee from the
earliest period has been kept by people in hives for the advantage
and enjoyment which its honey and wax gives. It is found wild in
North America in great numbers, storing its honey in hollow trees and
other suitable locations, but not native to this country, having been
introduced in North America by European colonists.

The story of the honey bee is one of the most interesting of all
stories of the living things found on the earth. The busy bee is the
ideal example of hard and persistent work and has for a long time been
the subject of interesting study for young and old. The bee is one of
the busiest of all of the world’s workers, and it is from the honey bee
that we get our expression “as busy as a bee”; such other expressions
as “to have a bee in one’s bonnet”; also such others as “quilting
bees” and “husking bees” are founded on the known activities of the
honey bee. The first expression means “to be flighty or full of whims
or uneasy motions” which comes from the restless habits of bees, and
“quilting bee” or “husking bee” originated from the knowledge that
bees work together for the queen. In a quilting bee or husking bee a
number of people get together and work together for a time for the
benefit of one individual.

[Illustration: WORKER-BEE.]

[Illustration: QUEEN-BEE, MAGNIFIED.]

[Illustration: DRONE-BEE.]


Honey Is Produced by Bees which Live in Colonies.

~HOW A BEE MAKES HONEY~

A colony of bees consists of one female, capable of laying eggs,
called the queen; some thousands of undeveloped females that normally
never lay eggs, the workers; and, at certain seasons of the year, many
males, the drones, whose only duty is to mate with the young queens.
These different kinds of individuals can readily be recognized by the
difference in size of various parts of the body, so that even the
novice at bee-keeping can soon recognize each with ease. This colony
makes its home in nature in a hollow tree or cave; but it thrives
perhaps even better in the hives provided for it by man. In a modern
hive, sheets of comb are placed in wooden frames which are hung in the
hive-box in such a way that they can be removed at the pleasure of the
bee-keeper. A sheet of comb is made up of small cells in which honey is
stored by the bees, and in which eggs are laid, and young bees develop.

[Illustration: BEES LIVING ON COMBS BUILT IN THE OPEN AIR.]


How Does a Bee Make Honey from Flower Nectar?

In the spring of the year the colony consists of a queen and workers,
there being no drones present at this time. During the winter the
bees remain quiet, and the queen lays no eggs, so that there are no
developing bees in the hive. The supply of honey is also low, for they
have eaten honey all winter, and none has been collected and placed
in the cells. As soon as the days are warm enough the bees begin to
fly from the hive in search of the earliest spring flowers. From these
flowers they collect the nectar, which is transformed into honey, and
pollen, which they carry to the hive on the pollen-baskets on the third
pair of legs.

[Illustration: CUCUMBER-BLOSSOM WITH A BEE ON IT; CAUGHT IN THE ACT.]

The nectar is taken by the bee into its mouth, and then passes to an
enlargement of the alimentary canal known as the honey-stomach, where
it is acted upon by certain juices secreted by the bee. The true
stomach lies just behind the honey-stomach; and if the bee needs food
for its own immediate use it passes on through the opening between the
two stomachs. On its arrival in the hive the bee places its head in one
of the cells of the comb and deposits there the nectar which it has
carried in. By this time the nectar has been partly transformed into
honey, and the process is completed by the bees by fanning the cells to
evaporate the excess of moisture which still remains. When a cell has
been filled with the thick honey the workers cover it with a thin sheet
of wax unless it is to be eaten at once. The pollen is also deposited
in cells, but is rarely mixed with honey. The little pellets which the
bees carry in are packed tightly into cells until the cell is nearly
full. If a cell of pollen be dug out of the comb, one can often see the
layers made by the different pellets. This collecting of nectar and
pollen continues throughout the summer whenever there are flowers in
bloom, and ceases only with the death of the last flowers in the autumn.


What Does the Queen Bee Do?

Almost as soon as the honey and pollen begin to come in, the queen of
the colony begins to lay eggs in the cells of the center combs. The
title of queen has been given to the female bee which normally lays
all the eggs of the colony, under the supposition that she governs the
colony and directs its activities. This we now know to be an error, but
the name still remains. Her one duty in life is that of egg-laying.
She is most carefully watched over by the workers, and is constantly
surrounded by a circle of attendants who feed her and touch her with
their antennæ; but she in no way dictates what shall take place in the
hive. The eggs are laid in the bottom of the hexagonal cells, being
attached by one end to the center of the cell. The first eggs laid
develop into workers, and are deposited in cells one-fifth of an inch
across. As the colony increases in size by the hatching-out of these
workers, and as the stores of honey and pollen increase, the queen
begins to lay in larger cells measuring one-fourth of an inch, and
from the eggs laid in these cells drones (or males) develop.

[Illustration: HOW HONEY DEVELOPS IN A COMB

THE DEVELOPMENT OF COMB HONEY.]

[Illustration: QUEEN-CELLS.]

[Illustration: THE QUEEN AND HER RETINUE.]

The eggs do not develop directly into adult bees, as might be inferred
from what has just been said; but after three days there hatches from
the egg a small white worm-like larva. For several days the larvæ
are fed by the workers, and the amount of food consumed is truly
remarkable. The larva grows rapidly until it fills the entire cell in
which it lives. The workers then cover the cell with a cap of wax, and
at the same time the larva inside spins a delicate cocoon under the cap.

[Illustration: HOW THE EGG OF THE QUEEN BEE LOOKS

EGG OF QUEEN UNDER THE MICROSCOPE.]

[Illustration: HOW HONEY DEVELOPS IN A COMB

THE DEVELOPMENT OF COMB HONEY.]


What Are Drone Bees Good for?

The worker brood can at once be distinguished from the drone brood by
the fact that the workers place a flat cap over worker brood and a high
arched cap over drone brood; and this is often a great help to the
bee-keeper in enabling him to determine at once what kind of brood any
hive contains. Twenty-one days from the time the egg is laid the young
worker-bee emerges from its cell, having gone through some wonderful
transformations during the time it was sealed up, this stage being
known as the pupa stage. For drones the time is twenty-four days.

[Illustration: HOW A SWARM WILL SOMETIMES OCCUPY A SMALL TREE AND BEND
IT OVER BY ITS WEIGHT.]

About the time the drones begin to appear, the inmates of the hive
begin to prepare for swarming, which, to any one watching the habits
of bees, is one of the most interesting things which takes place in
the colony. Several young worker larvæ are chosen as the material
for queen-rearing, generally located near the margin of the comb.
The workers now begin to feed these chosen larvæ an extra amount of
food and at the same time the sides of the cells containing them are
remodeled and enlarged by the destruction of surrounding cells. The
queen (or royal) cell is nearly horizontal at the top, like the other
cells of the comb, and projects beyond them; but then the workers
construct another portion to the cell into which the queen larva moves.
This is an acorn-shaped cell placed vertically on the comb, about as
large as three ordinary cells. As the cell is being built, the queen
larva continues to grow until the time comes for her to be sealed up
and enter her pupa state. Although it takes the worker twenty-one days
to complete its development, the queen passes through all the stages
and reaches a considerably larger size in but sixteen days.

[Illustration: THE DAILY GROWTH OF LARVÆ.]

[Illustration: DRONE-COMB.

WORKER-COMB.]

[Illustration: HOW THE HONEY COMB IS MADE

A STUDY IN CELL-MAKING.

Note that the cells are made independent of each other, and that it is
the refuse wax, like droppings of mortar in brick-laying, that seems to
tumble into the interstices to fill up.]

In the swarming season, at about the time the new queens are ready to
leave their cells, the old queen leaves the hive and takes with her
part of the workers, this being known as swarming.

[Illustration: CLIPPING THE QUEEN BEE’S WINGS

HOW TO BUMP THE BEES OFF A COMB.]

[Illustration: MANNER OF USING GERMAN BEE-BRUSH]

[Illustration: M. G. Dervishian’s method of catching queens, for caging
or clipping their wings, by means of a jeweler’s tweezers.]

[Illustration: “THE PROOF OF THE PUDDING IS IN THE EATING.”]

[Illustration: WHAT AN APIARY LOOKS LIKE

AN APIARY IN SUMMER.

This photo shows the windbreak of evergreens surrounding the yard. The
house-apiary is shown in the background, the upper story of which is
used as a workshop. A trellis of grapevines is placed in front of each
hive. In summer there is ample shade, and in the fall and early spring
the leaves are shed, leaving plenty of sun to strike the hives when it
is most needed.]

[Illustration: HOW THE HONEY MAN HANDLES THE BEES

A SWARM ENTERING A HIVE.]

[Illustration: A LIVE BEE-HAT.]

[Illustration: A FRAME OF BEES, SHOWING ONE WAY OF HOLDING AN UNSPACED
FRAME.]


How Do Bees Build the Honey Comb?

In the hands of a bee-keeper the departing swarm will be put into
another hive provided he wishes to increase the number of his colonies;
but in a state of nature the swarm will find an old hollow tree or
some similar place in which to establish itself. The bees, before
leaving their old hive, fill themselves with honey until the abdomen
is greatly distended, and for this reason it is not necessary for them
to collect nectar for a day or two, for they have other work to do.
Some of the bees begin to clean out the new quarters and get it fit for
occupancy; but most of them begin the construction of new combs. To
do this they suspend themselves in curtains from the top of the hive,
and remain motionless for some time. The wax used in building comb is
secreted by the workers in eight small pockets on the lower side of the
abdomen while they thus hang in curtains. Finally, after enough wax has
been formed, they begin to build. The small flakes of wax are passed
forward to the mouth, there mixed with a salivary secretion to make the
wax pliable, and then are placed on the top of the hive by the first
comb-builders. Other workers then come and place their small burdens of
wax on those first deposited, and this continues until the combs are
finished. There is more to comb-building than the mere sticking on of
wax plates, however, and nothing in all bee instincts is more wonderful
than the beautiful plan on which they build the comb. The cells are
hexagonal in shape, so that each cell in the center of the comb is
surrounded by six others. Nor is this the only remarkable thing in
their architecture, for each comb is composed of a double row of cells,
the base of each cell being formed of three parts, each one of which is
likewise a part of a separate cell of the other side of the comb. By
this method the bees obtain the greatest possible capacity for their
cells, with the least expenditure of wax. The accuracy of the cells of
the comb has in all ages been an object of admiration of naturalists
and bee-keepers.

As soon as there are some cells constructed, and even before the cells
are entirely completed, the queen begins to lay eggs, and the workers
begin to collect the stores of honey and pollen. They also collect in
considerable quantity a waxy substance from various trees, commonly
called propolis, with which they seal the inside of the hive, closing
up all openings except the one which serves as the entrance.

[Illustration: HOW THE HONEY BEE DEFENDS HIMSELF

EFFECT OF A STING NEAR THE EYE.]

The cells which are used for the storage of honey generally slant
upward slightly to help keep the honey from running out. Queen-cells
are made only when a new queen is to be reared.


Can a Bee Sting?

It is true that bees cannot bite and kick like horses, nor can they
hook like cattle; but most people, after having had an experience with
bee-stings for the first time, are inclined to think they would rather
be bitten, kicked, and hooked, all together, than risk a repetition of
that keen and exquisite anguish which one feels as he receives the full
contents of the poison-bag.


What Happens When a Bee Stings?

After the bee has penetrated the flesh on your hand, and worked the
sting so deeply into the flesh as to be satisfied, it begins to find
that it is a prisoner, and to consider means of escape. It usually
gets smashed at about this stage of proceedings, unless it succeeds
in tearing the sting--poison-bag and all--from the body; however, if
allowed to do the work quietly it seldom does this, knowing that such a
proceeding seriously maims it for life, if it does not kill it. After
pulling at the sting to see that it will not come out, it seems to
consider the matter a little, and then commences to walk around it,
in a circle, just as if it were a screw it was going to turn out of a
board. If you will be patient and let it alone, it will get it out by
this very process, and fly off unharmed. I need not tell you that it
takes some heroism to submit patiently to all this maneuvering. The
temptation is almost ungovernable, while experiencing the intense pain,
to say, while you give it a clip, “There, you little beggar, take that,
and learn better manners in future.”

Well, how does every bee know that it can extricate its sting by
walking around it? Some would say it is instinct. Well, I guess it is;
but it seems to me, after all, that it “sort o’ remembers” how its
ancestors have behaved in similar predicaments for ages and ages past.


Odor of the Bee-sting Poison.

After one bee has stung you, if you remain where you were stung, the
smell of the poison, or something else, will be pretty sure to get more
stings for you, unless you are very careful. It has been suggested that
this is owing to the smell of the poison, and that the use of smoke
will neutralize this scent. This probably is so.


What Should I Do If I Am Stung by a Bee?

The blade of a knife, if one is handy, may be slid under the
poison-bag, and the sting lifted out, without pressing a particle more
of the poison into the wound. When a knife-blade is not handy, push
the sting out with the thumb or finger nail in much the same way. It
is quite desirable that the sting should be taken out as quickly as
possible, for if the barbs once get a hold in the flesh, the muscular
contractions will rapidly work the sting deeper and deeper. Sometimes
the sting separates, and a part of it (one of the splinters, so to
speak) is left in the wound; it has been suggested that we should be
very careful to remove every one of these tiny points; but after trying
many times to see what the effect would be, I have concluded that they
do but little harm, and that the main thing is, to remove the part
containing the poison-bag before it has emptied itself completely into
the wound.


Why Are Some Races White, and Others Black, Yellow and Brown?

What you eat determines your color, according to Bergfield, a German
investigator. Not necessarily that you yourself could effect any change
in color, but your ancestors for thousands of years have unconsciously
been influenced by the food they have eaten and the drinks they have
drunk.

For instance, the original men were black, says Bergfield. Their chief
diet was of vegetables and fruits, he explains, and these same food
contains manganates that are not unlike iron. Dark browns and blacks
result from this combination. It is a scientific fact that negroes who
drink milk and eat meat are never as dark as those who eat vegetables.

Again, Mongols are yellow because they have descended from races that
were fruit-eating, and who, making their way into the deepest nooks
and widest plains of Asia, developed into shepherds and lived largely
on milk. Of course it is now known that milk contains a certain
percentage of chlorine, and has a decidedly bleaching effect. In the
case of Caucasians, they are said to have become white by adding salt
to their foods, which common salt is a strong chloride, and powerful in
bleaching the skin.

[Illustration: A HIDE HOUSE]




The Story in a Piece of Leather[9]

  [9] Pictures by courtesy of Endicott, Johnson & Co.


Where Does Leather Come From?

Leather is made by treating the hides of various animals such as the
calf, cow and horse. These are the principal animals from which we
obtain hides for making leather to make shoes. Before the hides are
fit for making shoes, they must be taken to a tannery where they are
prepared and tanned.

In viewing a tannery, we enter first the enormous hide house. It is
long, damp and dark. Here the hides are collected from all over the
world and stored, awaiting their turn for tanning. We follow a small
car of these hides into the beamhouse. We see the hides loaded into a
vat. They are soaked, resoaked, softened and split into sides. This
operation, while simple, holds your attention longer perhaps than any
of the others. Several hides after being softened are thrown over
a sort of saw-horse, the lot number is stamped on the hide in such
a manner that it appears on each side after being split. With an
unusually long bladed knife the workman quickly cuts down through the
center and the hides which are now called sides, fall to the floor.
They are next hooked together and pass on through vat after vat of lime
solution which loosens the hair and superfluous flesh. At the end of
this long chain of vats, we see the sides awaiting their turn at the
first unhairing machine, where all the hair is removed and then to the
fleshing machine, where the flesh is taken off and the sides are again
loaded in a car and pass on to the tanyard.

[Illustration: HOW THE HIDES ARE TREATED

THE TAN YARD

We resume our travels, following a car of sides from the beamhouse to
the sole leather tanyard. There are about 40 operations in the tanning
of sole leather, requiring about 100 days to produce first quality
leather. In the tanyard, we see more than 500 vats, each holding 300
sides, weighing about 23 pounds apiece. Each vat contains about 3000
gallons of liquor at an approximate cost of $100 a vat. Here we see
the sides slipped over sticks and placed in vats six feet deep, where
they receive the tanning, the real tanning process which preserves the
fibers giving the leather its life and long wearing qualities.

From the tanyard we go to the big wringers where the liquor is wrung
out, the hides are milled, dried and loaded on cars for the drying
loft, where they are allowed to dry or season preparatory to rolling.
This long building is sectioned off every 50 feet into chambers, where
the hides are hung in the same manner as in the vats. The temperature
of each room is changed from the outside temperature to a heat of 115
degrees, at which temperature the hides are dried and are ready for
rolling.]

[Illustration: In the rolling room, we see an operation requiring skill
and quickness of eye. The rollers pass to and fro over the side, which
is now hard and stiff, with a pressure of 300 tons. This rolling or
finishing gives it a high polish and we see a beautiful side of sole
leather, weighing from 18 to 25 pounds.]

[Illustration: HOW UPPER SHOE LEATHER IS TANNED

In the upper leather tannery we see the various operations preparatory
to the actual operation of tanning the hide, about the same as in
the sole leather tannery, with this difference: Upper leather in
this tannery is generally chrome tanned, a process requiring 30 days
and instead of vats sunken in the ground we see huge rolling drums
revolving at a rapid rate. This process is the most up-to-date method
and absolutely insures the wearing qualities of the leather. This
leather is very tough, yet is just as soft and pliable as glove leather
and as comfortable to the feet. It does not harden with age, nor does
it stiffen after being wet.]

[Illustration: UNHAIRING MACHINE

One of the most interesting sight while going through the tanneries is
the process of disposing of waste materials, such as hair, fleshings
and the sediments from the lime and sulphur vats.

The hair is separated into white, brown and black colors, each color
taking its turn through the huge mill or gin where the hair is dried
and afterwards baled. The brown and black are sold to plasterers. Those
who purchase the white often mix it with wool and use it for making
many useful articles.

The fleshings and trimmings are sold to manufacturers of glue.]

[Illustration: The Ancient Sandal Maker as pictured on the wall of the
ruined temples at Thebes, Egypt.]




The Story in a Pair of Shoes[10]

  [10] Pictures by Courtesy of United Shoe Machinery Co.


Who Made the First Shoes?

~WHERE SHOES COME FROM~

The making of shoes is one of the oldest arts of which there is any
human knowledge. Long before primitive man devised any method of
recording his exploits or thoughts, he contrived--through necessity--a
method of protecting his feet from the rough way or hot sands over
which he was obliged to travel in his search for food and shelter.

That foot covering antedates clothing or ornaments is shown from the
fact that the primitive savage to-day, devoid of clothing or ornament,
is almost invariably found with a crude form of foot protection and
there is scarcely a tribe or nation without it’s traditions of the
shoe--its mysterious power for good or evil.


What Was the First Foot Covering Like?

The first foot covering devised was undoubtedly a simple form of
sandal--a rough bit of hide, wood or plaited grass held to the foot by
means of thongs, generally brought up between the toes and tied about
the ankle. This form of foot covering is depicted in records of the
greatest antiquity: in the ruined temples at Thebes Egypt, the ancient
sandal maker is shown at his task; the Assyrian bricks show the ancient
warriors and people of that time wearing the simple sandal.

The dispersion of the human races and the wandering of tribes into
colder climates brought the necessity for more thorough protection
for the feet and body, and that this was accomplished was shown in
the gradual increase in the number of straps or thongs which held the
sandal in place and, in the colder climates, in the contrivance of
a bag-like foot covering--traces of which are found even now in the
Indian moccasin and the foot covering of the Eskimo. In all colder
countries this type of footwear is still in evidence, the seam around
the outline of the foot being a relic of the puckering string which
held the bag-like covering to the foot.

[Illustration: Ancient sandal showing puckering string and thongs for
holding it on foot.]

[Illustration: JAPANESE “ZORI”

A flat sandal with felt sole. Also showing “Tabi” or glove-like sock
worn by Japanese.]

The sandal was developed and adorned by the Greeks, but it was not
until the days of the Roman Empire that anything approaching the
present form of shoes was designed. In this period a form of foot
covering was developed--that was appropriated by the Emperor and worn
by him only--which covered the entire foot with the exception of the
toes.

[Illustration:

  THE
  EVOLUTION
  OF THE
  SANDAL
  TO THE
  SHOE]

[Illustration: ANCIENT AND MODERN FORMS OF SANDALS

Japanese Astrida or Rough Weather Clog.]

[Illustration: Ancient Turkish Bath Slipper.]

[Illustration: The Crakrow or Poulaine showing clearly traces of the
oriental origin of this design.]

[Illustration: Home made sandal of Siberian Peasant. Showing puckering
string and key strap.]

[Illustration: JAPANESE WARY

A primitive form of foot covering very generally used by Japanese at
the present time.]

[Illustration: Modern sandal issued by the Mexican Government for wear
of soldiers.]


The Boot Developed from the Sandal.

It was but a step from this form of foot covering to the boot which
covered not only the foot but the lower leg as well and which came
widely into use afterwards in the form of the Jack-boot.

Up to the fourteenth century there had been little in the way of
development of foot covering, but it is well established that in the
year 1408 there were shoemakers’ guilds in Europe. Some of these
were semi-religious in character, the members working in communities
and sharing in the general product of their toil. Guilds of this
period were very generally dedicated to either Saint Crispin or Saint
Crispianus (the patron saint of shoemaking), and even to this day
the birthday of Saint Crispin is celebrated in some of the English
shoemaking guilds on October 25. The ceremonies attending the
celebration in the olden days were of a very elaborate nature.

~THE SHOE WHICH THE CHURCH AND LAW FORBADE~

In the process of time the shoes began to lose the crude nature and
design in which the Dark Ages had held them and developed a style the
first of which was apparent in the gradual elongation of the toes,
the custom said to have been introduced by Henry, Duke of Anjou,
and these shoes were known as “Crakrows” or “Poulaines.” The style
finally ran to such extremes that effort was made to stop it by the
church and government, but with indifferent success until finally its
end was accomplished by the imposing of summary fines and threat of
excommunication by the church.

[Illustration: THE CRAKROW OR PEAKED SHOE OF THE FOURTEENTH CENTURY]

Immediately the style went to the other extreme and the toes became
very broad, as evidenced in the period of Elizabeth, and in some
instances the shoes were as broad as six inches at the toe. They were
made of velvet and were slashed to show the satin lining.


Who Made the First Shoes in America?

The first shoemaking in America is recorded when Thomas Baird arrived
on the second voyage of the Mayflower in 1628. Baird was under contract
with the Plymouth Company to make shoes for the colonists and brought
with him divers hides, etc., for this purpose. It was recorded that in
1636 a planter in Virginia employed six shoemakers to make shoes for
his slaves.

That in the early history of the country the art of making shoes had
become of considerable importance is shown by the very summary laws
passed by the different colonies regulating the industry. Particularly
was this so in the Province of Pennsylvania which, in 1721, placed upon
its statute book most drastic laws regarding the making of shoes and
regulating the prices to be charged therefor.

Shoemaking in New England early received impetus from the arrival of
one Phillip Kirtland, a Welshman, who came to Lynn, Mass., in 1636.
He was an experienced shoemaker and taught his art to many of the
colonists in his vicinity.

Shoemaking in this locality was further advanced by the arrival of
John Adams Dagyr, who settled in Lynn in the year 1750. Dagyr was a
celebrated shoemaker and was enabled, from his own means, to secure the
best examples of work from abroad. He possessed the peculiar quality
of being able to teach the art to those who came under his charge.

The fame of New England made shoes was due largely to the teachings
of these men and the industry has continued to be one of the first in
importance. In Massachusetts alone, according to the census of 1910,
over 40 per cent of the entire value of shoes in the United States was
produced.

The young man of this period, who essayed to learn the shoemaking
trade, was ordinarily apprenticed for a term of seven years under the
most rigorous terms, as shown in some of the indentures of that period
which are still in existence. He was instructed in every part of the
trade and, upon completion of his term of service, it was the custom
for the newly fledged shoemaker to start what was known as “whipping
the cat”--which meant journeying from town to town, living with a
family while making a year’s supply of shoes for each member thereof,
and then leaving to fill other engagements previously made.

It was soon found that the master workman could largely increase his
income by employing other men to do certain portions of the work, while
he directed their efforts, and this gradually lead to a division of
the labor and was the beginning of a factory system--which has been in
process of development from that time.

In the year 1795 it is recorded that there were in the city of Lynn,
Mass., over two hundred master workmen, employing over six hundred
journeymen, and that they manufactured shoes at the rate of about one
pair per day per man.

Factory buildings, as the words would be known to-day, were practically
unknown at that time. The small buildings, about ten feet square, were
in the back yards of many homes and in these little shops were employed
from three to eight men.

Strange as it may seem, prior to the year 1845 there had been little
change in the tools employed in making shoes. The workman of that
period, seated at his low bench, used practically the same implements
that were employed by his prototype, the ancient sandal-maker of
Egypt. The lap stone, the hammer, the crude needle and the knife being
practically the only tools used. Not that there had been no effort to
perfect machinery for this purpose; Napoleon I, in his endeavor to
secure better shoes for his soldiers, had offered great rewards for
the perfecting of shoe machinery that would accomplish this purpose,
but although great effort had been made there had been no successful
machinery produced.

In this year 1845 the first machine to be widely adopted by the
industry was perfected. It was a simple form of rolling machine, which
took the place of the lap stone and hammer used by the shoemakers for
toughening the leather, and it is said that a man could, in half an
hour, obtain the same results from this machine that would require a
day’s labor on the part of the hand workman employing the old method of
pounding.

This was followed in 1848 by the very important invention by Elias Howe
of the sewing machine--which was not adapted for use in connection with
sewing leather until several years later. It started, however, an era
of great activity among inventors and in 1857 there was perfected a
machine for driving pegs, which came into successful operation.


The First Machine for Making Shoes.

This was shortly followed by a very important invention by Lyman E.
Blake, of Abington, Mass., of a machine for sewing the soles of shoes
and this afterwards became famous as the “McKay Sewing Machine.” This
invention of Blake’s was purchased by Gordon McKay, who spent large
sums of money in perfecting it, and the first machine was established
in Lynn in 1861. The results obtained in the early stages of the
machines were of an indifferent nature and it was only after large
expenditures and the hiring of a number of different inventors to work
upon it that a successful machine was produced.

[Illustration: BOOTS OF THE CAVALIERS AND POSTILLIONS

FRENCH POSTILLION BOOT OF THE FIFTEENTH CENTURY]

[Illustration: THE CAVALIER BOOT OF THE FIFTEENTH CENTURY]

[Illustration: MILITARY JACK BOOT OF CROMWELL’S TIME]

[Illustration: MILITARY JACK BOOT OF SIXTEENTH CENTURY.]

~HOW SHOE MACHINERY WAS DEVELOPED~

While the quality of work was pronounced by manufacturers to be a
success, few had any faith in the possibility of manufacturing shoes
by machinery and McKay met with constant rebuffs in his endeavor
to introduce his machine. It is recorded that in his desperation
he finally offered to sell all the patent rights in machines which
he owned to a syndicate of Lynn manufacturers for the sum of
$250,000.00--the amount he had expended--but the offer was refused.

In his dilemma McKay at last offered to shoe manufacturers the use of
his machines on a basis, which afterwards became famous and an inherent
part of the shoe industry known as “royalty,” whereby McKay placed his
machines with manufacturers and participated to a small extent in the
amount of money saved. Owing to the fact that shoemakers were leaving
rapidly for the front and that there was a great scarcity of footwear,
the manufacturers gladly accepted this proposition and the machines
were very rapidly introduced.

The success of his early machines accomplished, McKay set about the
perfecting of others that would do different parts of the work and
there was accordingly great activity on the part of inventors in
their endeavor to perfect machines for the wide variety of uses made
necessary in the preparation of leather for shoemaking. There were soon
machines on the market for a wide variety of purposes--including the
lasting of the shoe, cutting the leather and for many other processes
necessary in making a complete shoe.

Contemporary with the early success of the McKay machines, a French
inventor, August Destoney, conceived the idea of making a machine
which would sew turned shoes--then a popular type of footwear for
women. After several years of endeavor he finally secured the interest
of John Hanan, a famous shoemaker of that time in New York City, and
through him the interest of Charles Goodyear--nephew of Goodyear of
India-rubber fame.

No sooner had the machine become perfected for the sewing of turned
shoes, however, than he set to work to make changes which would fit
it to sew welt shoes. (The welt shoe has always been considered the
highest type of shoemaking, as, by a very ingenious process, a shoe
is made which is perfectly smooth inside; all the other types having
a seam of thread or tacks inside which make them of considerable
disadvantage. He was able to accomplish this a few years later,
although the machines were not in extended use until about 1893, when
auxiliary machines for performing important parts of the work were
perfected; and from that time headway was made in the manufacture of
this high grade type of footwear.

The development of the industry--which has been very rapid with the
introduction of machinery--suffered materially in the latter part of
the last century through the bitter rivalry of machinery manufacturers,
a common process being the enjoining of manufacturers from the use of
machines on which it was claimed the patents were infringed and this
created a state of great uncertainty in the minds of many of those
manufacturing shoes.

This condition finally found its solution in the formation of one large
corporation, known in the shoe industry as the “United Shoe Machinery
Company,” which purchased the patents for a sufficient number of
machines to form a complete system for the “bottoming”--or fastening
the soles and heels of shoes--and finishing them.

These machines have been the subject of constant improvement and
others have been perfected to take care of operations which, prior to
their introduction, were purely hand operations. Each machine has been
standardized and so adapted to meet the requirements of those used in
connection with it that they collectively form the most remarkable and
efficient system of machines used at the present time.

Mention is made of this company owing to the important position it
has taken in the organization and advancement of the industry, the
American-made shoe being the one commodity of world-wide consumption
whose supremacy is not contested.

[Illustration: MY LADY’S SLIPPERS OF EARLY TIMES

EMBROIDERED RIDING BOOT WORN BY NOBLES DURING LAST DAYS OF POLISH
INDEPENDENCE]

[Illustration: EMBROIDERED RIDING BOOT FROM PERSIA OF ABOUT 1850]

[Illustration: FRENCH CALF BOOT MADE IN NEW YORK CITY, 1835]

[Illustration: LADY’S SHOE--PERIOD OF THE FRENCH REVOLUTION]

[Illustration: LADY’S SHOE--PERIOD OF LOUIS XVI.

Has wooden heel.]

[Illustration: LADY’S ADELAID OR SIDE LACED SHOE--PERIOD 1830 TO 1870]

[Illustration:

  CHANNEL LIP

  CROSS-SECTION OF INSOLE

  WOODEN LAST—DETERMINES SIZE AND SHAPE OF SHOE

  AN INSOLE

  AN INSOLE TACKED TO BOTTOM OF LAST

THE BEGINNING OF A SHOE]




How Shoes Are Made by Machinery


At the present time the types of shoes ordinarily made are but five:
the “peg” shoe, which is the cheapest type of shoe made; the “standard
screw,” which is used in the soles of the heaviest types of boots;
the “McKay sewed,” which is made after the fashion established by
Gordon McKay; the “turn” shoe, a light type of shoe which was invented
centuries ago and which is still worn at this time to a limited extent;
and the “Goodyear welt,” which has been universally adopted as the
highest type of footwear.

For this reason, this type of shoe has been selected to show the
methods employed in making shoes.

THE GOODYEAR WELT SHOE.--A Goodyear Welt shoe in its evolution from
the embryonic state in which it is “mere leather and thread” to the
completed product, passes through one hundred and six different pairs
of hands and is obliged to conform to the requirements of fifty-eight
different machines, each performing with unyielding accuracy the
various operations for which they were designed.

It might seem that in all this multiplicity of operations confusion
would occur, and that the many details and specifications regarding
material and design of any given lot of shoes in process of manufacture
would become hopelessly entangled with those of similar lots undergoing
the same operations. But such is not the case; for, when an order
is received in any modern and well-organized factory, the factory
management promptly take the precaution to see that all the details
regarding the samples to which the finished product is to conform are
set down in the order book. Each lot is given an order number and this
number, together with the details affecting the preparation of the
shoe upper, are written on tags--one for each two dozen shoes--which
are sent to the foreman of the cutting room. Others containing details
regarding the sole leather are sent to the sole leather room, while a
third lot is made out for the guidance of the foreman of the making or
bottoming room, when the different parts which have received attention
and been prepared according to specifications in the cutting and sole
leather rooms are ready to be assembled for the making or bottoming
process. If the tags which were sent to the cutting room were followed,
it would be found that on their receipt the foreman of this department
figured out the amount and kind of leather required, the kind of
linings, stays, etc., and that the leather, together with the tags
which gave directions regarding the size, etc., was sent to one of the
operators of the Ideal Clicking Machine.

~SHOEMAKING MACHINERY IS ALL BUT HUMAN~

This machine has been pronounced one of the most important innovations
that have been made in the shoe manufacturing industry during recent
years, as it performs an operation which has heretofore successfully
withstood every attempt at mechanical aid. Prior to its introduction,
the cutting of upper leather was accomplished by the use of patterns
made with metal edges, which were laid upon the leather by cutter, who
then ran a small sharp knife along the edges of the pattern, cutting
the leather to conform to it. This was a slow and laborious process,
and if great care was not taken, there was a tendency to cut away from
the pattern; and in many cases, through some slip of the knife, the
leather was cut beyond the required limits.

This machine has a cutting board very similar to those which were used
by the hand workman and over it is a beam which can be swung either
to the right or to the left, as desired, and over any portion of the
board. Any kind of skin to be cut is placed on the board, and the
operator places a die of unusual design on it. Grasping the handle,
which is a part of the swinging beam, he swings the beam over the die,
and on downward pressure of the handle a clutch is engaged which brings
the beam downward, pressing the die through the leather. As soon as
this is accomplished, the beam automatically returns to its full height
and remains there until the handle is again pressed.

The dies used are but three-quarters of an inch in height and are so
light that they do not mar the most delicate leather when placed upon
it. They enable the operator to see clearly the entire surface of the
leather he is cutting out, and it is obvious that the pieces cut by the
use of any given die must be identically the same.

After the different parts required by the tag have been cut out by the
operator of the Clicking Machine, some of the edges which show in the
finished shoe must be skived or thinned down to a beveled edge. This
work is performed by the Amazeen Skiving Machine--a wonderful little
machine in which the edge to be skived is fed to a sharp revolving
disk that cuts it down to the desired bevel. The machine does the
work in a very efficient manner, conforming to all the curves and
angles. This skiving is done in order that the edges may be folded,
to give the particular edge on which it is performed a more finished
appearance. The skived edges are then given a little coating of cement
and afterwards folded on a machine which turns back the edge and
incidentally pounds it down, so that it presents a very smooth and
finished appearance.

Aside from the work of skiving toe caps and folding them, there is
generally a series of ornamental perforations cut along the edge of
the cap. This is done very often by the Power Tip Press, by means of
which the piece to be perforated is placed under a series of dies which
cuts the perforations in the leather according to a predetermined
design, doing the work all at one time. The number of designs used
for this purpose are many and varied, combinations of different sized
perforations being worked out in innumerable designs.

On one of the top linings of each shoe there has been stamped the
order number, together with the size of the shoe for which the linings
were intended. After all the linings have been prepared in accordance
with the instructions on the tag, they, in connection with the various
parts of the shoe, receive attention from the Stitchers, where all the
different parts of the upper are united. The work is performed on a
range of wonderful machines, which perform all the different operations
with great rapidity and accuracy.

At the completion of these operations the shoe is ready to receive the
eyelets, which are placed with remarkable speed and accuracy by the
Duplex Eyeletting Machine. This machine eyelets both sides of the shoe
at one time with bewildering rapidity. The eyelets are securely placed
and accurately spaced; and as both sides of the upper are eyeletted at
one time, the eyelets are placed directly opposite each other, which
greatly helps the fitting of the shoe, as thereby the wrinkling of the
shoe upper is avoided.

With the completion of this operation, the preparation of the shoe
upper is finished, and the different lots with their tags are sent to
the bottoming room to await the coming of the different sole leather
portions of the shoe. These have been undergoing preparation in the
sole leather room, where on receipt of tag the foreman has given
directions for the preparation of outsoles, insoles, counters, toe
boxes and heels, to conform with the requirements of the order.

The soles are roughly died out from sides of sole leather on large
Dieing-out Machines, which press heavy dies down through the leather;
but to make them conform exactly to the required shape, they are
generally rounded out on a machine known as the “Planet Rounding
Machine,” in which the roughly died-out piece of leather is held
between clamps, one of which is the exact pattern of the sole. On
starting the machine, a little knife darts around this pattern, cutting
the sole exactly to conform with it.

The outsole is now passed to a heavy Rolling Machine, where it is
subjected to tons of pressure between heavy rolls. This takes the place
of the hammering which the old-time shoemaker gave his leather and
brings the fibres very closely together, greatly increasing its wear.

This sole is next fed to a machine called the “Summit Splitting
Machine--Model M,” which reduces it to an exactly even thickness. The
insole--which is made of very much lighter leather--is prepared in
much the same manner, and in this way it will be noticed that both the
insole and outsole are reduced to an absolutely uniform thickness.

The insole also receives further preparation; it is channeled on the
Goodyear Channeling Machine. This machine cuts a little slit along the
edge of the insole, extending about one-half inch towards its center.
It also cuts a small channel along the surface.

The lip which has been formed by the Goodyear Channeling Machine is now
turned up on the Goodyear Lip Turning Machine, so that it extends out
at a right angle from the insole, forming a lip or shoulder against
which the welt is sewed. The cut which has been made on the surface
inside this lip serves as a guide for the operator of the Welt Sewing
Machine, when the shoe reaches that stage.

The heels to be used on these shoes have also been formed from
different lifts of leather which are cemented together. The heel is
then placed under great pressure, giving it exact form and greatly
increasing its wear.

~THE DIFFERENT PARTS OF THE SHOE COME TOGETHER~

The counters are also prepared in this room, as well as the toe boxes
or stiffening, which is placed between the toe cap and the vamp of
the shoe. When these are all completed, they are sent to the making
or bottoming room, where the completed shoe upper is awaiting them.
Here a wonderfully ingenious little machine called the “Ensign Lacing
Machine,” passes strong twine through the eyelets and in a twinkling
ties it automatically. This is done so that all parts of the shoe will
be held in their normal position while the shoe is being made. The
knot tied by this machine is perfect and is performed with mechanical
exactness. On high-grade shoes this work was formerly performed by
hand and it will be readily recognized how difficult it was to obtain
uniformity. The spread of the upper at the throat can be regulated
perfectly when this machine is used. The different parts of the shoe
now commence to come together. The workman places the toe box, or
stiffening, in the proper location as well as the counter at the
heel, and draws the upper over the last. To the bottom of this last
has already been tacked by means of the U. S. M. Co. Insole Tacking
Machine--which drives tacks automatically--the insole, which, it will
be noticed, conforms exactly to the shape of the bottom of the last.
This last, made of wood, is of the utmost importance, for upon the last
depends the shape of the shoe.

[Illustration: EACH SHOE MACHINE DOES SOMETHING DIFFERENT

ASSEMBLING MACHINE

Operator locates back seam of upper on last. Machine drives two tacks
which hold it in place.]

The shoe as completed up to this point with the parts mentioned
fastened together as shown, is now ready for assembling. The workman,
after placing the last inside the shoe upper, puts it on the spindle of
the Rex Assembling Machine, where he takes care that the seam at the
heel is properly located. He presses a foot lever and a small tack is
driven part way in, to hold the upper in place. He then hands it over
to the operator of the Rex Pulling-Over Machine.

[Illustration: PULLING-OVER MACHINE

Draws shoe upper smoothly down to last. Operator adjusts it so that
each seam occupies correct position on last. Machine automatically
drives back to hold it in place.]

This machine is a very important one; for as the parts of the shoe
upper have been cut to exactly conform to the shape of the last, it is
necessary that they should be correctly placed on the last to secure
the desired results. The pincers of this machine grasp the leather at
different points on each side of the toe; and the operator, standing
in a position from which he can see when the upper is exactly centered,
presses a foot lever, the pincers close and draw the leather securely
against the wood of the last. At this point the operation of the
machine halts. By moving different levers, the workman is able to
adjust the shoe upper accurately, so that each part of it lies in the
exact position it was intended when the shoe was designed. When this
important operation has been completed, the operator again presses a
foot lever, the pincers move toward each other, drawing the leather
securely around the last, and at the same time there are driven
automatically two tacks on each side and one at the toe, which hold the
upper securely in position. These tacks are driven but part way in, so
that they may be afterward removed.

[Illustration: THE LASTING MACHINE ONE OF THE MOST IMPORTANT

HAND METHOD LASTING MACHINE

Last sides of shoe.]

[Illustration: LASTING MACHINE

Last toe and heel of shoe.]

The shoe is now ready for lasting. This is one of the most difficult
and important parts of the shoemaking process, for upon the success of
this operation depends in a great measure the beauty and comfort of the
shoe. The Consolidated Hand Method Welt Lasting Machine, which is used
for this purpose, takes its name from the almost human way in which it
performs this part of the work. It is wonderful to observe how evenly
and tightly it draws the leather around the last. At each pull of the
pincers a small tack driven automatically part way in holds the edge
of the upper exactly in place, so that in the finished shoe every part
of the upper has been stretched in all directions equally. The toe and
heel of the shoe are considered particularly difficult portions to last
properly. This important part of the work is now being very generally
performed on the U. S. M. Co. Lasting Machine--No. 5, a machine of
what is known as the “bed type.” It is provided with a series of
wipers for toe and heel, which draw the leather simultaneously from
all directions. There can be no wrinkles at the toe or heel of shoe on
which it is properly used and the quality of work produced by it has
been very generally recognized as a distinct advance in this important
part of shoemaking. After the leather has been brought smoothly around
the toe it is held there by a little tape fastened on each side of the
toe and which is held securely in place by the surplus leather crimpled
in at this point. The surplus leather crimpled in at the heel is
forced smoothly down against the insole and held there by tacks driven
by a very ingenious hand tool in which there is a constantly renewed
supply of tacks.

[Illustration: A MACHINE THAT FORMS AND DRIVES TACKS

UPPER STAPLING MACHINE

Forms small staples from wire.

Holds shoe upper to lip of insole.]

[Illustration: UPPER TRIMMING MACHINE.

Trims off surplus part of shoe upper and lining.]

In all of the lasting operations the tacks are driven but part way in,
except at the heel portion of the shoe, where they are driven through
the insole and clinched on the iron heel of the last. The tacks are
driven only part way in, in order that they may be afterward withdrawn
so as to leave the inside of the shoe perfectly smooth. In making
shoes other than Goodyear Welts, with the exception of the Goodyear
Turn Shoe, it is necessary to drive the tacks through the insole and
clinch them inside the shoe, so that the different portions of the sole
inside the shoe have clinched tacks. These are left even after the shoe
is finished. This smooth interior of the shoe is one of the essential
features of the Goodyear Welt Process.

In the lasting operation there is naturally a surplus amount of leather
left at the toe and sometimes around the sides of the shoe, and this is
removed on the Rex Upper Trimming Machine in which a little knife cuts
away the surplus portion of the leather very smoothly and evenly, and
simultaneously a small hammer operating in connection with the knife
pounds the leather smooth along the sides and the toe of the shoe. The
shoe then passes to the Rex Pounding Machine, in which a hammer pounds
the leather and counter around the heel so that the stiff portion of
the shoe conforms exactly to the shape of the last.

The shoe is now ready to receive the welt, which is a narrow strip of
leather that is sewed along the edge of the shoe, beginning where the
heel is placed and ending at the same spot on the opposite edge. This
welt is sewed from the inside lip of the insole, so that the needle
passes through the lip, upper and welt, uniting all three securely
and allowing the welt to protrude evenly along the edge. The needle
in making this stitch does not go inside the shoe, but passes through
only a portion of the insole, leaving the inside perfectly smooth. This
part of the work was formerly one of the most difficult and laborious
tasks in shoemaking. As it was performed entirely by hand, the drawing
of each stitch depended upon the strength and mood of the workman.
It is of course obvious that with different operators stitches were
oftentimes of different lengths and drawn at different tensions; for
human nature is much the same everywhere, and it is impossible for a
workman who has labored hard all day to draw a stitch with the same
tension at night as might have been possible in the morning.

[Illustration: AN AUTOMATIC SEWING MACHINE WHICH NEVER TIRES

WELT AND TURNED SHOE SEWING MACHINE

Upper portion shows operator at machine. The lower shows formation and
location of stitch formed by this machine.

  Welt Stitch

  Welt]

It is surprising how quickly and easily the work is done on the
Goodyear Welt Sewing Machine. This famous machine has been the
leading factor in the great revolution that has taken place in shoe
manufacturing. Its work should be carefully noted--all stitches of
equal length and measured automatically, the strong linen thread
thoroughly waxed and drawn evenly and tightly; for the machine never
tires, and it draws the thread as strongly in the evening as in the
morning. Every completed movement of the needle forms a stitch of great
strength, which holds the welt, upper and insole securely together.

As the lasting tacks as well as the tacks which hold the insole in
place on the last were withdrawn just prior to this operation, it will
be seen that the inside of the shoe is left perfectly smooth. After
this process the surplus portions of the lip, upper and welt which
protrude beyond the stitches made by the Goodyear Welt Machine are
trimmed off by the Goodyear Inseam Trimming Machine--a most efficient
machine, in which a revolving cup-shaped knife comes in contact with
the surplus portions of the leather and trims them off very smoothly
down to the stitches.

[Illustration: PUTTING THE GROUND CORK AND RUBBER CEMENT IN SHOES

INSEAM TRIMMING MACHINE.

Trims shoe upper lining and lip of insole smooth down to stitches.]

[Illustration: WELT BEATING AND SLASHING MACHINE

Beats welt so that it stands out evenly round edge of shoe.]

[Illustration: PLACING SHANK AND FILLING BOTTOM.

Workman tacks shank in place and fills bottom with ground cork and
rubber cement.]

At this stage the shoe is passed to the Universal Welt Beater, in which
a little hammer vibrating very rapidly beats the welt so that it stands
out evenly from the side of the shoe. As the leather is bent around
the toe, it is the natural tendency of the welt to draw more tightly
at that place, and this is taken care of by a little knife which the
operator forces into operation, in the beating process, the toe is
being taken care of, and it makes a series of little cuts diagonally
along the edge of it. The insole and welt now receive a coating of
rubber cement. This cement is contained in an air-tight tank and is
applied by means of a revolving brush, which takes its supply of
cement, as required, from a can.

In this way, an even coating of any desired thickness is given to the
insole and welt. This machine has many advantages; the cement being
closely confined in the tank, there is almost no waste in its use.
Formerly, when this was done by hand, the waste through evaporation or
lack of care on the part of the workman was very material.

The heavy outsole of the shoe also receives at this time proper
attention. The flesh side of this sole, or the side next to the animal,
receives a coating of rubber cement, and after it has dried slightly
the operator of the Goodyear Improved Twin Sole Laying Machine takes
the work in hand. In this machine there is a rubber pad, or mould,
which has been made to conform to the curve in the sole of the shoe.
After placing the last on the spindle, which is suspended from the
machine and hangs over the rubber mould, the outsole having been
previously pressed against the bottom of the shoe, the operator by
pressing the foot lever causes this arm to descend, forcing the shoe
down into the mould, so that every portion of the sole is pressed
against the bottom of the shoe and welt. Here they are allowed to
remain for a sufficient length of time for the cement to properly set,
the operation being repeated on a duplicate part of the machine, the
operator leaving one shoe under pressure while he is preparing another.

[Illustration: MACHINES WHICH PUT THE SOLES ON SHOES

SOLE LAYING MACHINE.

Presses outsole to bottom of shoe where it is held by rubber cement.]

[Illustration: ROUNDING AND CHANNELLING MACHINE.

Roughly rounds outsole and welt to conform to shape of last. Cuts small
channel along edge for stitches.]

The next operation is that of trimming the sole and welt so that they
will protrude a uniform distance from the edge of the shoe. This work
is performed on the Goodyear Universal Rough Rounding Machine, which
gauges the distance exactly from the edge of the last. It is often
desired to have the edge extended further on the outside of the shoe
than it does on the inside and also that the width of the edge should
be considerably reduced in the shank of the shoe. This is taken care of
with great accuracy by the use of this machine. The operator is able
to change the width at will. By the use of this remarkable machine the
operator is also enabled to make the sole of the shoe conform exactly
to all others of similar size and design.

[Illustration: CHANNEL OPENING MACHINE.

Turns back lip of channel preparatory to stitching.]

[Illustration: CHANNEL CEMENTING MACHINE.

Coats surface of channel so it may be laid to cover stitches.]

The surplus portion of the leather is now trimmed off on the Heel-Seat
Rounding Machine, and the channel cut by the knife on the Rough
Rounding Machine is turned up so that it leaves the channel open. This
is done by the Goodyear Universal Channel Opening Machine, in which a
little wheel, turning very rapidly, lays the lip smoothly back.

~SEWING THE SOLE TO THE SHOE~

The outsole is now sewed to the welt. This operation is performed on
the Goodyear Outsole Rapid Lockstitch Machine, which is very similar in
operation to the Goodyear Welt Sewing Machine used in sewing the welt
to the shoe. The stitch, however, is finer and extends from the channel
which was cut for it to the upper side of the welt, where it shows
after the shoe has been finished. The lockstitch formed by this machine
is a most durable one. Using a thoroughly waxed thread, it holds the
outsole securely in place, even after the connecting stitches have been
worn off. This is one of the most important machines in the shoemaking
process. It is able to sew even in the narrow shank, where a machine
using a straight needle could not possibly place its stitch.

The “Star Channel Cementing Machine--Model A” is again called into
operation for the purpose of coating with cement the inside of the
channel in which this stitch has been made. A special brush with guard
is used for this purpose, and the operation is very quickly performed
by the skilled operator.

After this cement has been allowed to set a sufficient length of time,
the channel lip, which has previously been laid back against the sole,
is again forced into its former position and held securely in place
by rubber cement. This work is done by the Goodyear Channel Laying
Machine, in which a rapidly revolving wheel provided with a peculiar
arrangement of flanges forces back into place, securely hiding the
stitches from observation on this portion of the shoe.

[Illustration: MACHINES WHICH PUNCH THE SOLES OF SHOES

CHANNEL LAYING MACHINE.

Rubs channel lip down to cover stitches.]

[Illustration: LOOSE NAILING MACHINE

Drives small nails which hold outsole in place at heel.]

The next operation is that of leveling, which is performed on the
Automatic Sole Levelling Machine--one of the most interesting used
in the shoemaking process. This is a double machine provided with
two spindles, on one of which the operator places a shoe to be
levelled. It is securely held by the spindle and a toe rest, and on
the operator’s pressing a foot lever, the shoe passes automatically
beneath a vibrating roll under heavy pressure. This roll moves forward
with a vibrating motion over the sole of the shoe down into the shank,
passes back again to the toe, then cants to the right, and repeats the
operation on that side of the shoe, returning to the toe and canting to
the left, repeating the operation on that side; after which the shoe
automatically drops forward and is relieved from pressure. This rolling
motion removes every possibility of there being any unevenness in the
bottom of the shoe, and while one shoe is under pressure the operator
is preparing a second one for the operation.

[Illustration: AUTOMATIC LEVELLING MACHINE.

Rolls out any unevenness in soles.]

[Illustration: HOW THE HEEL OF A SHOE IS PUT ON

  TOP LIFT

  COMPRESSED HEEL

  BEFORE OPERATION
  AFTER OPERATION

  Heel Attaching

WORK PERFORMED BY HEELING MACHINES.]

[Illustration: AUTOMATIC HEEL LOADING AND ATTACHING MACHINE.]

[Illustration: SLUGGING MACHINE.

Drives small pieces of ornamental metal which protect the heel.]

[Illustration: HEEL TRIMMING MACHINE.

Trims rough lifts of heel to desired shape.]

[Illustration: HEEL BREASTING MACHINE.

Cuts the breast of the heel to correct angle and curve.]

[Illustration: EDGE TRIMMING MACHINE.

Trims edge of outsole smoothly.]

[Illustration: A LUMP OF PULP.

Paper such as found in this book is made from trunks and limbs of trees.

The use of good fibers in book paper is a guarantee of quality and
durability. The above illustration represents a lump of this pulp
prepared for the beaters.]




How the Paper in this Book is Made


Where Does Paper Come From?

Egyptians were the first people to make what would today be called
paper. They made it from a plant called papyrus and that is where the
name comes from.

This plant is a species of reed. The Egyptians took stalks of reed cut
into as thin slices as they could, laid them side by side; then they
arranged another layer on top with the slices the other way and put
this in a press. When dried and rubbed until smooth, it made a kind of
paper, which could be written upon.

One of the first substances used for making the kind of paper we have
today was cotton. Paper was made from cotton about 1100 A. D. From this
thin cotton paper our present papers are a development, i.e., paper
today is largely made of vegetable fibers. Vegetable fibers consist
mostly of cellulose surrounded by other things which hold the short
vegetable fibers together.

The fibers best adapted for making paper are those of the cotton and
flax plants, and while the uses of paper were few, no other material
was needed when it was once learned that cotton and linen fibers would
do for making paper. All we had to do was to save all the old rags and
sell them to the paper man.

In making paper from rags, the rags were allowed to rot to remove the
substances that incrust the cellulose, and then beaten into a pulp,
to which a large quantity of water was added. This pulp was put into
a sieve, until the greater part of the water had been drained off by
shaking, and the fibers remaining formed a thin layer on the bottom of
the sieve. This layer of fiber was put into a pile with other similar
layers, and the whole pile was placed under a press, where more of
the water was removed. When they were dry, we had a very fair kind of
paper which was, however, not much better than blotting paper and could
not be written on with ink because it was loose in texture and very
absorbent.

To give it good writing surface it was necessary to fill the pores.
This was done by sizing which gave the paper great firmness. Paper was
sized by drawing the layers of paper through a solution of alum and
glue, or some similar substances, and then drying them, then finally
passed between highly polished rollers to iron it. This gave it the
necessary smooth hard surface.

In the modern method of making rag paper by machinery, the rags are
boiled with caustic soda, which separates the cellulose fibers, and
placed in a machine in which rollers set with knives tear the rags
to pieces and mix them with water to form a pulp. This is called a
breaker. The pulp is then bleached with chloride of lime, and is passed
on to the sizing machine. This machine mixes the pulp with alum and
with a kind of soap, made from suitable resins which serves the purpose
better than glue.

[Illustration: NOT A WOOD YARD BUT THE OUTSIDE OF A PAPER MILL.

This shows the great piles of trunks and limbs of trees near a wood
pulp paper mill used in making paper for newspapers, books, magazines,
etc.]


How Is the Water Mark Put Into Paper?

The pulp, which is now ready to be made into paper, is poured out upon
an endless cloth made of fine brass wire. This cloth travels constantly
in one direction, by means of rollers, and is given at the same time
a sort of vibratory motion, to cause the paper fibers to become more
closely felted together. On the wire cloth web are usually woven words,
or designs, in wire, that rise above the rest of the surface. These
are transferred to the paper, and are called water marks. The machine
then winds the finished paper into rolls, so that it may be handled
conveniently.

~HOW PAPER IS NOW MADE FROM WOOD~

During the past few years the uses for paper have increased so greatly
that there have not been enough rags available to meet the demand for
material, and a successful effort was made to find other material from
which paper could be made. Many fibers were tried before it was found
that wood pulp could be used. Straw and esparto grass, a plant that
grows wild in North America, were found to yield cellulose having the
desired qualities and were used to some extent. But the problem was
solved when it was learned that pulp made from trunks and limbs of
trees would serve even then. At first the powder formed by grinding up
logs was used, but the paper produced was not strong, and could be used
for very few purposes.

[Illustration: GREAT FORESTS TURNED INTO PAPER

PAPER TREES.

This picture shows the trees as they grow in the woods. These trees are
good for making paper. Your morning paper, may some morning be printed
on what is left of one of these trees.]

It was discovered finally that if wood shavings were boiled in strong
solutions of caustic soda, in receptacles that would withstand very
high pressure, the wood fibers were separated, and a very good quality
of cellulose for paper manufacture produced, provided it was bleached
before being made into paper, and most of our paper to-day is,
therefore, made of wood.

Later on this process gave way to the sulphite process. In the sulphite
process, a solution of sulphite of lime is used. Acid sulphite of lime
results when the fumes from burning sulphur are passed through chimneys
filled with lime. By this process the separation of the fibers and the
bleaching are done at the same time and an even whiter paper making
material is obtained.

The sulphite process is now used almost exclusively in making paper
from wood.

[Illustration: GRINDING ROOM.

In this picture we see how the trees are first cut into smaller chunks
before being reduced to chips for making pulp.]

The discovery of the process of making paper from wood has led to the
use of paper for many purposes for which it could otherwise never have
been used. The wood pulp is also used in the form of papier-mâché, a
tough, plastic substance, which is made by mixing glue with it, or by
pressing together a number of layers of paper having glue between.
Papier-mâché can easily be molded into almost any form, and after
drying forms a very tough substance and one that will stand rough
usage. It has been employed for making dishes, water baskets and
utensils of many other kinds, for making the matrices for and from
electrotype plates, for car wheels, and many other purposes.

[Illustration: WHERE THE INGREDIENTS FOR MAKING PAPER ARE MIXED

MIXING ROOM.

The wood fiber must be mixed with other ingredients when paper is made
from it. This shows a corner of the large electro-chemical department
for the production of bleach and soda used in the preparation of rag
and wood fibres.]

[Illustration: THE WATER SUPPLY.

A good deal of water is needed in making paper. From twelve to fifteen
million gallons daily are drawn from the river and filtered through
this plant in Maine; clean paper of bright color being dependent upon
the use of pure water.]

[Illustration: BEATING THE INGREDIENTS FOR MAKING PULP

BEATER ROOM.

The ingredients for making paper are first mixed thoroughly in machines
called “beaters” before going to the paper making machines. The
operation of beating is one of the most important in paper making.]

[Illustration: THE PAPER COMING OFF IN ROLLS.

As the paper progresses through the machines, it passes over a long
series of heated cylinders, drying and hardening the stock until it
reaches the finished end. This illustration shows a web 135 inches
wide being cut into two rolls. The air pressure in the machine room is
slightly greater than the atmospheric pressure outside, preventing dust
from entering.]

[Illustration: GREAT PAPER-MAKING MACHINES IN OPERATION

PAPER MAKING MACHINES.

In the foreground is the so-called wet end showing the vats in which
the liquid pulp, about 98 per cent water, is pumped. It is screened and
then flows on to an endless wire web beyond, where the free water is
taken out by drainage and by suction boxes.]

[Illustration: PUTTING THE PRINTING SURFACE ON THE PAPER

PAPER STOCK.

A large amount of stock of paper mills. This paper is seasoned by
holding it in stock and will be later given such surface as is called
for.]

[Illustration: COATING MACHINES.

Where the paper passes through a bath of coating mixture to a long
drying gallery at the end of which it is rewound preparatory to being
given the highly finished surface on the calendaring machine.]

[Illustration: A section of Finishing Room department where paper is
passed through alternating compressed fiber and steel rolls giving
it the surface required for different classes of printing. The paper
on which the Book of Wonders is printed has a highly finished smooth
surface so that the pictures will come out clear.]

[Illustration: WHERE THE PAPER IS CUT IN SHEETS

The finished rolls of stock pass through rotary cutters which produce
the sheets of various required sizes. The paper in the Book of Wonders
was cut in sheets 41x55 inches, thus making it possible to print 32
pages on each side of each sheet.]

[Illustration: Rotary Boiler for cooking rags or wood in making pulp
for use in manufacture of paper.]

  Illustrations showing manufacture of paper by courtesy of S. D.
  Warren & Co.

[Illustration: HOW THE PRINTED TYPE OF THIS BOOK WAS SET

This picture shows the wonderful Linotype machine by which the type
of this book was “set,” as the printers say. The men who operate the
machine are compositors. Originally the type matter of books was set
by hand and the compositor composed in type what the author of the
book had written. By pressing down on the keys which you see in the
picture, the compositor sets the words in lines of metal. This machine
is almost human. By touching the proper keys, the operator assembles a
line of matrices the details of which are explained in another picture,
and after this is done the machine automatically casts a slug from
them, turns and delivers a slug into a galley ready for use and finally
distributes the matrices back into their respective channels in the
magazine, where they are ready to be called down again, by the touch of
the key button. The latest model linotype has four magazines and can be
equipped with matrices which when assembled will cast lines in from six
to twelve different sizes and styles of type.

The assembling mechanism is the only part of the linotype where the
human mind is applied to the working of the machine. It is necessary
for the eye to read what is to be printed, and the mind, through the
medium of the fingers, to translate this into assembled lines of
matrices; after that the machine acts automatically.]

[Illustration: THE LINOTYPE—FOUR MACHINES IN ONE

The keyboard is made up of 90 keys, which act directly on the matrices
in their channels in the magazine. The slightest touch on the
keybuttons releases the matrix, which drops to the assembler belt and
is carried swiftly to the assembler. When a word is assembled, the
spaceband key is touched and a spaceband drops into the assembler.
When the necessary matrices and spacebands to fill the line have been
assembled, the operator raises the assembler by pressing a lever on the
side of the keyboard. When the assembler reaches its highest point it
automatically starts the machine and the matrices are transferred to
the casting position.

This illustration shows the manner in which matrices are constantly
circulated in the Linotype. From the magazine they are carried to the
assembler, then passed to the mold, where the line is cast, and from
the mold after casting they are raised to the top of the machine and
redistributed to their proper channels in the magazine.

The Linotype is sometimes called a typesetting machine, but this is not
correct: it does not set type. It is a substitute for typesetting. It
is strictly speaking a composing machine, as it does composition but
its product is not set type, but solid slugs in the form of lines of
type with the printing face cast on the edge.

It is in reality four machines so arranged that they work together in
harmony--the magazine, the assembling mechanism, the casting mechanism
and the distributing mechanism. The magazine is at the top of the
machine sloping to the front at an angle of about 31 degrees, and
consists of two brass plates placed together with a space of about
five-eighths of an inch between. The two inner surfaces are cut with 92
grooves or channels running the up and down way of the magazine, for
carrying the matrices. The matrices slide down these channels on edge,
with the face or punched edge down, and the V-end extending toward the
upper part of the magazine. Each of these channels will hold twenty
matrices.]

[Illustration: LITTLE PIECES OF BRASS WHICH PRODUCE SOLID TYPE

ONE-LETTER AND TWO-LETTER MATRICES.

Linotype matrices are made of brass. In the edge of each matrix is
either one or two letters or characters in intaglio. The thickness of
the individual matrices is dependent on the width of the character.
By an ingenious arrangement either one-letter or two-letter matrices
can be used in the same machine, and either character on a two-letter
matrix can be used at will.

The two-letter matrix bears two characters, one above the other, one
of which may be a Roman face and the other an italic, small capital,
or black face. If a line is to be composed partly of the Roman face,
which is in the upper position on the matrix, and partly of the other
face, which is in the lower position, this is accomplished by means of
a slide on the assembler operated by a small lever.

When the lower characters on the matrices are required, the slide
is shifted and the matrices are arrested at a higher level, so that
the lower characters align with the upper characters of the other
matrices in the assembler. When the slide is withdrawn the matrices are
assembled at the lower level. By means of this simple contrivance, a
line may be composed partly of one face, partly of the other face, or
entirely of either face.]

[Illustration: THIS SHOWS HOW THE HEADINGS ARE MADE IN CAPITALS OF
DIFFERENT TYPE.

Linotypes are guaranteed to be capable of setting above 5000 ems of
6 point per hour, and this output is widely obtained in commercial
printing offices with first class operators. When a compositor speaks
of the amount of type he sets per hour or day he speaks of “ems.” A
column of type matter is so many “ems” wide. The term “em” means the
square of the particular size of type that is being set. Thus if a
column is said to be 13 ems wide it means that an em quad or square,
could be set 13 times in the width of the column. Type is graded
according to size by points. Machine type for book work runs from 5
points to 12 points. A point is one seventy-second of an inch, that is,
there are 72 points to an inch. This guarantee, however, by no means
indicates the limit of speed at which the machine can be operated, as
evidenced by records of 10,000 to 11,000 ems per hour maintained for an
entire day. The rapidity of the Linotype is limited only by the ability
of the operator to manipulate the keys, and the extreme capacity of the
machine has never yet been attained.]

[Illustration: HOW THE LINOTYPE MAKES SOLID TYPE

SECTIONAL VIEW OF MAGAZINE SHOWING CHANNEL FULL OF MATRICES.

This picture shows the machine with part of the magazine top and
side removed. We can thus see how the matrices are arranged in their
respective grooves in the magazine. When one of the keys of the
keyboard is pressed down the first matrix in the corresponding grove in
the magazine escapes and drops upon a conveyor belt and is carried in
its proper order to an assembler, which answers much the same purpose
as a printer’s stick. The correct spacing or justification of the line
of matrices is accomplished by means of spacebands, which are assembled
automatically between the words in the line by the touch of a lever at
the left of the keyboard.]

[Illustration: LINOTYPE SLUGS.

Instead of producing single type characters, the Linotype machine casts
metal bars, or slugs, of any length desired up to 36 ems, each complete
in one piece and having on the upper edge, properly justified, the
characters to print a line. These slugs are automatically assembled
in proper order as they are delivered from the machine, when they are
immediately available either for printing from direct or for making
electrotype or stereotype plates. They answer the same purpose and are
used in the same manner as composed type matter.]

[Illustration: CASTING THE SLUGS OF SOLID METAL

LINE OF MATRICES BEING LIFTED TO DISTRIBUTOR

After the slug has been cast, the matrices are carried up to the second
transfer position, where they are pushed to the right, and the teeth in
the V at the top of the matrices engage the grooves in the distributor
bar of the second elevator, which descends from the distributor box at
the same time that the matrices rise to the second transfer position.
The second elevator then rises toward the distributor box, taking the
matrices with it, but leaving the spacebands; these are then pushed to
the right and slide into the spaceband box, to be used again.

As the second elevator rises toward the distributor box with its load
of matrices, the distributor shifter lever moves to the left until
the elevator head has reached its place by the distributor box. It
then moves back to the right and pushes the matrices off the second
elevator distributor bar into the distributor box, where they meet the
“matrix lift” and are lifted, one at a time, to the distributor screws
and distributor bar proper. The teeth in the matrix and the grooves in
the bar are so arranged that when a matrix arrives at a point directly
over the channel in which it belongs, it “lets go” and drops into its
channel.

If, however, there is a matrix in the line which was not designed to
drop into one of the channels operated from the keyboard, it will be
carried clear across the distributor bar and dropped into the last
channel, and from there it will find its way to the sorts box.]

[Illustration: SECTIONAL VIEW OF METAL POT WITH LINE OF MATRICES IN
POSITION BEFORE THE MOLD

The casting mechanism consists of the metal pot, mold disk, mold,
ejector, and trimming knives. The illustration shows a cross-section
of the metal pot, mold disk, and mold, with a line of matrices in the
casting position. When the line of matrices leaves the assembler,
they pass to a position in front of the mold disk. The disk makes a
one-quarter turn to the left, which brings the mold from the ejecting
position, where it stands while the machine is at rest, to the casting
position. It then advances until the face of the mold comes in contact
with the matrices. The metal pot advances until the pot mouthpiece
comes in contact with the back of the mold; at this point the pump
plunger descends and forces the metal into the mold and against the
matrices. The pot then recedes, the mold disk withdraws from the
matrices and makes three-fourths of a revolution to the left, stopping
in the ejecting position, from which it started. The slug is ejected
and assembled in the galley.

During the last revolution of the disk the bottom of the slug is
trimmed off, and in the process of ejection the sides of the slug are
trimmed, so that when it drops in the galley the slug is a perfect line
of type, ready for the form.]

[Illustration: HOW THE PRINTED PART OF A BOOK LOOKS AT FIRST

As the slugs of type, each of which represents a line, come from the
linotype machine, they are arranged in order in a brass holder the
width of the line of type, called a “galley.” This holder is about
twenty inches long. As soon as it is filled one of the men in the
typesetting office takes it to a proof press where he makes a rough
impression of it. He runs an ink covered roller over the top of the
slugs, lays a piece of blank paper on it and then either runs another
roller over it or puts it in a hand press and secures an impression of
the type just as it is. This is called making a “galley proof.”

The galley proof is then sent to the proof-reader who reads it
carefully and indicates such errors in setting as appear and must be
changed. Before correcting the actual type, however, the composing
room sends the galley proof to the one who is publishing the book.
The publisher also reads the proof over carefully and, if he does not
wish to change any of the wording, he sends it back to the composing
room with his “O. K.” attached in writing. If he wishes to change
the wording, he does so and the galley proof is then returned to the
composing room marked “O. K. after corrections and changes are made.”

The linotype operator then makes whatever changes are desired or
necessary by setting new lines where mistakes or changes occur. If
there is only one wrong letter in a line, he must reset the whole line
as the machine, as you remember, only turns out solid lines of type. A
revised proof is then sent to the publishing office and, if no further
changes are to be made, he gives instructions to have the “galley” made
up into pages. How the pages are made up is shown in the next picture.]

[Illustration: HOW THE PAGES OF A BOOK ARE MADE UP

When the revised proofs come back from the publisher ready to be made
into pages, the publisher has marked on same what pictures are to go on
the pages of the “make up” as this is called. The compositor then picks
out the pictures in the form of cuts which are to go on the different
pages and puts them in the page first. He then arranges the type matter
from the galley proof around, above or below the pictures, puts in the
proper headings and takes a “final proof” of how the pages are arranged
to look. If this is satisfactory the publisher puts a “final O. K.”
on the proof in writing and the page is ready to be printed. Thus the
book is made up page by page. No page is printed without the O. K. of
the publisher and so, if there are any errors still in the page, the
publisher is responsible.]

[Illustration: HOW THIS BOOK IS PRINTED

PRINTING THE BOOK OF WONDERS

This picture shows the pages of the Book of Wonders being printed.
Thirty-two pages are printed on each side of a sheet of paper at
one time. A printing office is a busy place as can be seen from the
picture. As soon as the ink is dry on the printed sheets they are taken
to the bindery where they are folded and sewed ready to have the covers
put on.]

[Illustration: HOW THE BOOK OF WONDERS IS BOUND

When the printed sheets are received in the bindery they are fed into
a folding machine which is shown here. A sheet of 64 pages is folded
and cut and delivered in four sections of 16 pages each ready to be
gathered.]

[Illustration: Here we see a machine which takes the folded sections of
16 pages each, which are called “signatures,” and sorts them, dropping
them into compartments in order, so that each compartment finally
contains the printed matter for one book all arranged in the order
which it will be bound.]

  Courtesy of the J. F. Tapley Co. New York.

[Illustration: SEWING THE PAGES OF THE BOOK OF WONDERS

Here we see the girls at work operating the sewing machines which sew
the sections together at the back side of the book.]

[Illustration: The men in this picture are making the backs of the
books round and preparing them for the putting on of covers.]

  Courtesy of the J. F. Tapley Co., New York.

[Illustration: THE BOOK OF WONDERS IS READY TO READ

In this picture we see the “case makers” at work making the covers on
which the actual book is bound.]

[Illustration: The book is now “bound” by having the covers put on and
is ready for distribution.]

  Courtesy of the J. F. Tapley Co., New York.


How Is Photo Engraving Done?

[Illustration: This cut shows a section of a photo-engraving screen
enlarged, illustrating the squares above-mentioned. In reality it would
take from 100 to 400 of these dots to make an inch, according to the
fineness of screen.]

~HOW THE PICTURES IN THIS BOOK ARE MADE~

The first step is the making of the halftone negative which differs
from an ordinary negative in being made up of different sized dots
instead of shades of gray. This result is obtained by photographing the
picture through a halftone screen consisting of two pieces of glass,
ruled with black lines and cemented together so the lines cross at
right angles and leave small squares of clear glass.

The effect of making the negative in this way is to represent the
different shades from black to white by large or small dots. Wet plate
photography is usually used in this process because the film is thinner
and more intensely black besides being cheaper than dry plates.

[Illustration:

  New Process Engraving Co.

This cut shows a portion of a halftone cut enlarged so that the dots
can be seen very plainly.]

Having made the negative the next step is to make a printing plate
from it. To do this, a piece of metal, copper if the work is fine, and
zinc for coarser work, is coated with a solution which is sensative to
light, fish glue is commonly used to which is added a small amount of
ammonium bichromate. The metal being coated and dried, it is put in
a very strong frame with the negative and squeezed together so that
they are in perfect contact. A powerful light is now directed upon the
negative with the metal behind it, the result being that wherever the
light goes through the white spaces in the negative, the coating on the
metal is rendered insoluble. Where the dots on the negative are, the
light is unable to get at the coating so that when the metal is removed
from the frame and thoroughly washed this part of the coating washes
away, leaving the part which the light got at attached to the metal.
This is now heated until the enamel, as the coating is called, turns
dark brown and the picture can be easily seen.

The picture is now on the metal but it must be made to stand out in
relief before it can be used for printing from, so it is put in a bath
of acid which eats away that part of the metal left uncovered by the
washing away of the coating and this leaves the dots which make up
the picture standing up in relief. A roller covered with very thick
paste-like ink is now rolled over the picture, or cut as it is now
called, and when a piece of paper is pressed against the ink covered
cut each little dot leaves a mark of ink on the paper the total making
up the picture as we see it.

There are many more wonderful things connected with the making of cuts
such as the routing machine which has a tool that revolves so fast
that it turns around 300 times while the clock ticks once, and other
machines which cut hard metal as easily as you can cut a potato with a
knife.

Colored pictures are also made by the process outlined above. The
picture is photographed three times with a different colored piece of
glass in front of the lens, the result being three negatives, one of
which has all the blue, one all the red and the other all the yellow
in the picture. By making cuts from each negative and printing them
on top of one another in yellow, red, and blue, the original picture
is reproduced in all its colors. This is how all our pretty magazine
covers are made.




ACKNOWLEDGMENT


The Editors of the Book of Wonders make acknowledgment herewith to the
following. All mentioned have been a great assistance in making the
book not only possible but authentic:

  Spencerian Pen Co.
  Eastman Kodak Co.
  American Telephone & Telegraph Co.
  Remington Arms Co.
  Bethlehem Steel Co.
  American Portland Cement Manufacturers Assn.
  Brainerd & Armstrong Silk Co.
  Corticelli Silk Co.
  Curtiss Aeroplane Co.
  U. S. Beet Sugar Industry.
  Hartford Carpet Co.
  Haynes Automobile Co.
  Jacobs & Davis, Engineers.
  Pennsylvania Railroad Co.
  Endicott, Johnson & Co.
  United Shoe Machinery Co.
  Sherwin-Williams Co.
  Pittsburgh Plate Glass Co.
  The Colliery Engineer.
  Lake Torpedo Boat Co.
  Western Union Telegraph Co.
  New York Edison Co.
  Westinghouse Lamp Co.
  Consolidated Gas, Electric Light and Power Co. of Baltimore.
  Browning Engineering Co.
  The White Star Line.
  Marconi Wireless Co.
  Plymouth Cordage Co.
  American Woolen Co.
  The Vitagraph Co.
  The B. F. Goodrich Co.
  The Goodyear Rubber and Tire Co.
  The Lexington Chocolate Co.
  The Hecker-Jones Milling Co.
  The White Oak Mills.
  The H. C. White Company.
  A. I. Root Company.
  Kohler & Campbell.
  Browne & Howell Co.
  P. & F. Corbin.
  Otis Elevator Co.
  Scientific American.
  Joseph Dixon Crucible Co.
  Homer W. Laughlin Co.
  S. D. Warren & Co.
  C. B. Cottrell & Sons Co.
  Mergenthaler Linotype Co.
  J. F. Tapley & Co.
  New Process Engraving Co.
  Mutual Film Corporation.
  Tobacco Trade Journal Co.
  McClure’s Magazine.
  James Arthur.
  Seth Thomas.
  American Locomotive Co.
  New York Central Railroad Co.
  Columbia Rope Co.
  Carl Werner.
  National Wool Growers Assn.




INDEX


  =Acid=, carbonic, what it is, 509

  =Aerial=, on ship, (illus.), 455

  =Aeroplanes=, English Channel crossing (illus.), 132
    Curtiss biplane (illus.), 131
    first demonstrations of, 130
    first flight in Europe, 129
    first man-carrying (illus.), 128
    first successful (illus.), 126
    gas motors used in, 130
    gliding, 137
    greatest present value of, 136
    records of, 131
    red wing (illus.), 131
    what two brothers accomplished for, 130
    Wright Bros.’ inventions, 130

  =Age=, why do we, 196

  =Air=, does it move with the earth? 400
    does it weigh anything? 398
    dust in, 38
    extend, how far does, 243

  =Airlocks=, description of in tunnel building, 213

  =Ammunition=, first invention of, 40
    fixed, 47
    in prehistoric times, 40

  =Animals=, can they think? 194
    is man an, 180
    that leap greatest distance, 122
    which foretell weather, 240

  =Anthracite seams= (illus.), 260

  =Aqueduct= (illus.), 505

  =Are= matches poisonous, 294

  =Armor=, in the Middle Ages, 44

  =Army=, wireless in the, 448-451

  =Are= there two sides to the rainbow? 254

  =Arrow=, what causes it to fly? 408

  =At= what point does water boil? 220

  =At= what rate does thought travel? 242

  =Australian Ballot=, where first used, 122

  =Automobile= (illus.), axle, location of, 186
    beginning of, 183
    carburetor, location of, 184
    carburetor, use of, 184
    chassis, complete, 188
    cog-wheels, use of, 183
    cog-wheels, location of (illus.), 183
    crankcase, location of (illus.), 183
    cylinder, location of (illus.), 184
    drive shaft, location of (illus.), 187
    electric generator, use of, 185
    exhaust, 184
    fenders, location of, 188
    fenders, use of, 188
    finished car (illus.), 189
    first American (illus.), 189
    fly-wheel, location of (illus.), 183
    fly-wheel, use of, 183
    frame (illus.), 186
    gasoline, what it does, 183
    gasoline tank, location of, 187
    gears, location of (illus.), 183
    gears, use of, 183
    heart of (illus.), 184
    how improved, 190
    magneto, location of, 185
    magneto, use of, 185
    marvellous growth of twenty years, 189
    modern power plant complete, 190
    oil pan, use of, 184
    oil pump, location of, 184
    piston, location of (illus.), 183
    piston, use of, 183
    power plant, an (illus.), 185
    radiator, location of (illus.), 188
    radiator, use of, 188
    ready for the wheels, 187
    second stage of construction (illus.), 186
    self-starter, location of, 185
    self starter, use of, 185
    Smithsonian exhibit of complete power plant, 190
    springs, location of (illus.), 186
    springs, use of, 186
    steering gear, location of (illus.), 187
    street scene 20 years ago, 189
    transmission, location of, 186
    tire pump, use of, 185
    tires, how made, 382
    transmission, use of, 186
    water pump, location of, 185
    water pump, use of, 185
    what the completed chassis looks like (illus.), 188

  =Bacon, Roger=, discoverer of gunpowder, 44

  =Balance=, effect of sunlight on, 37

  =Baldness=, chief course of, 143
    why some people are, 143

  =Ball=, why it bounces, 63
    bearings, what they are, 180

  =Balloon=, what keeps it up, 199
    why it goes up, 199

  =Ballot=, when first used, 122
    Australian, where first used, 122

  =Bearings, Ball=, what they are, 180

  =Bee=, how it lives, 336
    why it has a sting, 336

  =Bell, Alexander Graham= (illus.), 70
    first telephone, 72

  =Bend=, why things, 62

  =Biplanes=, Curtiss (illus.), 131
    in flight, Curtiss (illus.), 136

  =Birds=, how do they find the old home? 408
    how they learn to fly, 178
    how they find their way, 407
    reproduction of life in, 179
    why do they sing? 408

  =Birds’ Eggs=, why different colors, 233

  =Blasting= gelatin, definition of, 206

  =Bleriot, M.=, first European flights, 129

  =Blotter=, capillary attraction of, 18
    how it takes up ink, 18

  =Blush=, why do we, 194

  =Boat=, how it can sail under water, 269
    hydroplane of submarine, 270
    inside of a submarine (illus.), 272

  =Bodies=, swiftest moving, 25

  =Boiling= point of water, 220
    what makes water, 220

  =Boring mill= (illus.), 56

  =Bottles=, gurgle in, 63

  =Bounce=, why a ball will, 63

  =Bow=, long (illus.), 42

  =Bow-and-Arrow=, invention of, 43

  =Boxes=, match, how made, 294

  =Brazil, Emperor of=, receives first words over telephone, 74

  =Bread=, how flour is made, 462
    difference in Graham and whole wheat, 461
    grinding wheat (illus.), 464
    harvesting wheat, 460
    loaves of world (illus.), 459
    origin and meaning of, 460
    purifying machine (illus.), 463
    separating fibre germs (illus.), 463
    wheat conditioning (illus.), 462
    when wheat was first used in making, 461
    where it comes from, 460
    why so important, 460

  =Break=, why things, 62

  =Breech=, of a big gun, 53

  =Breech-loaders= in Civil War, 48
    in rifle, 47

  =Brush=, in writing, invention of, 13
    in writing (illus.), 13

  =Bullets=, cupro-nickel used in, 50
    grading of, 51
    weighing of (illus.), 49

  =Buildings=, concrete, how made (illus.), 100

  =Buttons=, on sleeves, 64

  =Building=, tallest in the world (illus.), 395-508
    what holds it up? 496

  =Building foundations=, construction of, 496
    compressed air, use of (illus.), 500
    cutting piles with a hot flame (illus.), 498
    driving steel piles, 496
    piles filled with concrete (illus.), 499
    piles, length of, 497
    piles, sinking of (illus.), 497
    use of oxyacetylene, 498

  =Cable, laying= armoring machine (illus.), 437
    arrived on other side, 433
    bulge (illus.), 437
    gear-paying-out (illus.), 431
    Great Eastern, the, 434, 437
    landing of (illus.), 433
    machinery on cable ship (illus.), 431
    paying-out machine (illus.), 431
    shore end of (illus.), 429
    storing of, aboard ship (illus.), 430
    what they look like when cut in two (illus.), 428

  =Cable, ocean=, Continental Morse Code, 438
    how dropped (illus.), 432
    how repaired (illus.), 435
    inventor of, 434
    laid, how, 429
    man who made it possible, 434
    pioneers of, 434
    signals as received (illus.), 438
    what is it made of, 429

  =Cable, repairing=, grapnels (illus.), 435
    how repaired, 435
    on rocky shore, (illus.), 438
    powerful engines used (illus.), 436
    splicing of (illus.), 436

  =Cable, service=, map of Trans-Atlantic, 439

  =Cable, vault=, of telephone (illus.), 67

  =Cabriolet=, 122

  =Cacao, beans=, bags of (illus.), 388
    how cured, 392
    nibs, 392

  =Cacao=, flaked, how made, 392
    how gathered, 391
    pods, how gathered, 391
    free, discovery of, 388
    and chocolate, difference between, 389

  =Cackling=, why a hen, 233

  =Calibre= of a gun, 53

  =Calico=, name, where from, 123

  =Camera=, 22
    first moving picture, 375

  =Can= a bee sting? 536

  =Can= animals think? 194

  =Candles=, did they come before lamps? 294
    why it burns, 21
    why it gives light, 21
    why you can blow out, 21-36
    when introduced, 296

  =Candy=, why do children like? 409
    why does eating candy make some people fat? 409

  =Carbon=, 352

  =Carbonate of Soda=, used in developing, 23

  =Carburetor=, in gas engine, 184

  =Carpets=, carding machine (illus.), 170
    dyeing the yarn, (illus.), 170
    examining and repairing (illus.), 173
    how yarn is dyed, 170
    manufacture of (illus.), 169
    modern, how made, 169
    packing for shipment (illus.), 173
    processes, 169-170-171, 173
    stamping designs, 173
    view of factory (illus.), 172
    weaving, by machine (illus.), 171
    wool, packing machine (illus.), 169
    wool sorting, 170

  =Cartridges=, invention of, 48
    types of (illus.), 49

  =Cave=, man who invented ammunition, 40

  =Cement=, alumina in, 95
    amount used in United States, 95
    arch, 95
    bagging (illus.), 99
    bridges, 95
    bucket (illus.), 97
    burned (illus.), 98
    calcined (illus.), 98
    clay in, 95
    crusher (illus.), 97
    dams, 95
    fireproof, 95
    grinders (illus.), 98
    industry, 95
    in water, 95
    kiln (illus.), 98
    lime in, 95
    machine (illus.), 97
    marl in, 95
    mill (illus.), 96-98
    mixing (illus.), 99
    mortar, 99
    on farms, 95
    origin, 95
    plastic, 95
    Portland, 95
    powder (illus.), 98
    quarry (illus.), 96
    reinforced, 95
    rock (illus.), 95-97
    sewers, 95
    shale in, 95
    shovel (illus.), 96
    sidewalks, 95
    silica in, 95
    strength of, 95
    subways, 95
    tunnels, 95
    walls, 95
    what is it, 95
    what made of, 95
    what used for, 95
    weighing (illus.), 99
    where obtained (illus.), 97

  =Chalk=, where it comes from, 18

  =Chattering=, why do my teeth, 218

  =China-making=, blungers, 404
    clay, in making dishes, 405
    decorating cups (illus.), 404-406
    dishes, how shaped, 405
    glazing plates (illus.), 404
    grinders (illus.), 404
    how the dishes are shaped, 405
    molding (illus.), 405
    pressing water from clay (illus.), 405
    pulverizing materials, 404
    pulverizing mill (illus.), 404
    saggers (illus.), 406
    taking the dishes from kiln (illus.), 406

  =Chinese=, probable discovers of gun powder, 44

  =Chocolate=, broma, what it is, 390
    cacao beans (illus.), 388
    cacao pods, (illus.), 391
    cacao tree, discovery of, 388
    cocoa butter, 390
    cocoa mill (illus.), 390
    cocoa roaster (illus.), 390
    cocoa shells, 390
    cracking mill, 389
    cream mixing (illus.), 393
    difference between and cacao, 394
    dipping department, 394
    finisher (illus.), 392
    flaked cocoa, 392
    heating machine (illus.), 393
    how are chocolate candies made? 394
    how made, 392
    making, 393
    milk, how made, 394
    mill (illus.), 392
    mixer (illus.), 393
    shell separator (illus.), 389
    what cocoa butter is, 390
    wrapping individual, 394

  =Cigars=, how they are made, 517

  =Clay=, what is, 495

  =Circles=, tendency to walk in, 91

  =Clinking= glasses, how it originated? 232

  =Clock=, age of, 319
    largest in the world (illus.), 321
    machinery which runs a big (illus.), 322
    in Independence Hall (illus.), 323
    in New York City Hall, 323

  =Cloth=, beaming (illus.), 89
    Burling (illus.), 88
    Burr picker, 87
    chloride of aluminum in making, 98
    English cap spinning (illus.), 89
    finished, ready for market (illus.), 90
    finish perching (illus.), 90
    fulling (illus.), 90
    how made from wool, 85
    how made perfect, 83
    how woolen is dyed, 87
    mending perching (illus.), 88
    napping, 89
    piece dyeing (illus.), 90
    ring twisting (illus.), 89
    sulphuric acid solution in making, 87
    teasel, 89
    weaving and scouring (illus.), 88
    web, 86
    woolen mule spinning (illus.), 89
    worsted carding (illus.), 85
    yarn inspecting (illus.), 89

  =Clothes=, cost of wool in a suit of, 83
    of wool, 80
    wool in one suit of, 83

  =Coal=, anthracite, 257, 258
    anthracite seams (illus.), 260
    breaker (illus.), 257
    cars ready to go to surface (illus.), 260
    dangers to the miners, 262
    electric cap lamp (illus.), 264
    firedamp, 262
    gas illuminating from, 299
    gases, 262
    history of the safety lamp (illus.), 263
    how the miners loosen the coal (illus.), 261
    how the slate pickers work (illus.), 259
    lamp which saves many lives, 263
    man who invented the safety lamp, 264
    mine workers that never see day light, 258
    mules and their drivers (illus.), 258
    peat, 262
    safety lamp and firedamp, 262
    seams (illus.), 260
    shaft gate (illus.), 260
    slate pickers (illus.), 259
    soft, 259
    spiral slate pickers (illus.), 259
    stable underground (illus.), 258
    undercutting with compressed air machines (illus.), 261
    undercutting with pick (illus.), 261

  =Cocoa=, see Cacao

  =Cocoon=, description of, 115
    completed (illus.), 116
    from which moths have emerged (illus.), 117
    how silk is reeled from, 118
    moths emerging from (illus.), 117
    number required to one pound of silk, 117
    silkworm beginning of (illus.), 116
    silkworm, preparing for making of (illus.), 116

  =Coins=, gold, 266
    in glass of water, 38
    silver, 266

  =Cohesion=, definition of, 219, 220

  =Cold=, why some things are, 144

  =Color=, exposed to light rays, 36
    in paint, 229
    what it is, 123

  =Colors=, different in birds’ eggs, 233
    in sunset, cause of, 253

  =Color=, of rainbow, 253
    red, why it makes a bull angry, 490

  =Columbus=, brought first sheep to America, 80

  =Comb honey=, development of (illus.), 529

  =Compounds=, compared with elements, 349

  =Compressed air=, method in building tunnels, 211

  =Concrete=, buildings (illus.), 100
    construction (illus.), 100
    decay, 101
    engineering, 102
    forms (illus.), 100
    houses (illus.), 101
    loads (illus.), 100
    mold, 101
    ornamental (illus.), 100
    practical uses of (illus.), 100
    rusting, 100
    Silo (illus.), 102
    stable (illus.), 102
    sun dial (illus.), 101
    tensile strain, 104
    tower (illus.), 102
    walls (illus.), 100
    water tower (illus.), 102
    what it is, 95
    wood, 102

  =Confucius=, philosophy written with brush, 13

  =Cooking=, when first used, 308

  =Copper=, as a conductor of electricity, 267
    wire, telegraph, 266

  =Corn plant=, how pollen fertilizes, 170
    why it has silk, 176

  =Corn Silk=, what it is for, 176
    baling presses (illus.), 476

  =Cotton=, drawing frames (illus.), 472
    slashers (illus.), 475
    spinning frames (illus.), 473
    warping machine (illus.), 474
    what nation produces the most, 477
    how much cloth will a pound of cotton make, 477
    mill (illus.), 471
    cloth, first steps in making, 472
    putting fiber on bobbins (illus.), 473
    cloth finished (illus.), 476
    who discovered, 477
    weave room, 475
    where it comes from, 470
    lapper machines, 471
    card room (illus.), 472
    bobbins (illus.), 473
    dye-house (illus.), 474
    beaming frames (illus.), 475
    inspecting tables (illus.), 476
    field a southern (illus.), 470
    breaker machines (illus.), 471
    slubber machines (illus.), 472
    speeders (illus.), 473
    spooling machine (illus.), 474
    shipping (illus.), 476
    what used for, 477
    cloths, what are the principle, 477

  =Counting=, man, himself, 19
    in tens, 19
    in twelves, 20

  =Crying=, what makes us, 195
    when hurt, why we, 93

  =Cross-bow=, invention of, 44

  =Crude rubber=, how treated, 378

  =Culverins=, early type of, 45

  =Cylinder in gas engine= (illus.), 184

  =Darkness=, cats can see in, 91
    some animals can see in, 91
    why we cannot see in, 91
    why we fear, 352

  =Deep sea diving=, the telephone adjusting (illus.), 202
    coming up (illus.), 204
    cost of outfit, 203
    helmet, putting on (illus.), 202
    just before going down (illus.), 204
    outfit, 202
    shoes, putting on (illus.), 202
    suit, putting on (illus.), 202
    telephoning from bottom, 203
    telephone, testing the (illus.), 203
    testing, final (illus.), 203
    water pressure at varying depths, 203
    wealth recovered by diving, 204
    weight of outfit, 203

  =Deer-stalking with the cross-bow= (illus.), 42

  =Detonators=, in firearms, 47

  =Developer=, Pyro, in photography, 23

  =Diamonds=, what made of, 351

  =Did= candles come before lamps? 294

  =Die=, why do we have to, 245

  =Difference= in woolens and worsteds, 84

  =Dimples=, what causes, 352

  =Discovery= of gunpowder, 44

  =Discovery= of stringed musical instruments, 479
    telephone, 71

  =Diver’s= task made easy (illus.), 284

  =Diving, deep-sea=, the telephone adjusting, (illus.), 202
    cost of outfit, 203
    hats of divers, 204
    just before going down (illus.), 204
    helmet, putting on (illus.), 202
    shoes, putting on (illus.), 202
    suit, putting on the (illus.), 202
    suit, what consists of, 202
    telephone from bottom, 203
    telephoning, testing the (illus.), 203
    testing final (illus.), 203
    water pressure at varying depths, 203
    wealth recovered by diving, 204
    weight of outfit, 203

  =Dixie=, what name means, 124
    where name originated, 123

  =Does= air weigh anything, 398

  =Does= the air surrounding the earth move with it? 400

  =Does= thunder sour milk, 196

  =Does= light weigh anything? 37

  =Does= the sun revolve on its axis? 511

  =Do= father and mother plants always live together? 176

  =Do= the ends of the rainbow rest on land? 254

  =Do= the stars really shoot down? 255

  =Dog=, why he turns round before lying down, 229

  =Dolls=, why girls like, 368

  =Dom Pedro=, Emperor of Brazil, who saved the telephone, 73

  =Do= plants breathe? 241

  =Draft=, created by chimney, 37

  =Dreams=, cause of, 366
    nightmare, 367
    what makes us? 366

  =Drinking=, origin of clinking glasses, 232

  =Driving shield=, airlock bulkhead (illus.), 210
    erector (illus.), 210
    in tunnel building (illus.), 208
    inventor of, 209
    tunnels, front view (illus.), 209

  =Ducks=, why water runs off backs of, 233

  =Dust=, in air, 38
    what it is, 104

  =Dyeing=, silk, 121

  =Earache=, what causes, 410

  =Earth=, how big it is, 124
    light surrounding, 38

  =Echo=, what makes an, 200
    whispering gallery, 201

  =Eggs=, birds why different colors, 233
    silkworm, how imported, 111

  =Egyptians=, how ancients wrote, 12

  =Electric arc=, temperature of, 35

  =Electric current=, what it is, 334

  =Electricity=, conductors of, 331
    current, 334
    good conductors, 331
    how discovered, 333
    non-conductors, 331
    what is, 329

  =Electric lighting=, arc-light, 307
    Edison’s first lamp (illus.), 306
    incandescent carbon lamp (illus.), 306
    Mazda lamp (illus.), 306
    tantalum lamp (illus.), 306
    Tungsten metal lamps, 305
    when introduced, 305

  =Elements=, carbon, 352
    compared with compounds, 349
    hydrogen, 349
    nitrogen, 350
    oxygen, 349
    what an is, 349

  =Elevator=, description of (illus.), 397
    installation (illus.), 396
    principal parts of, 396
    why does not the car fall? 397

  =Emperor=, saved the telephone, 73

  =Emperor of Brazil=, receives first message over first telephone, 74

  =Engine, gas= (illus.), 181-182
    carburetor, 184
    cylinder (illus.), 184
    horse-power, of, 256

  =Exchange=, first telephone, 75

  =Exhibition=, of first telephone at Centennial, 74

  =Experiments=, with mirror resultant in photograph, 22

  =Exploding=, a submarine mine, 34

  =Explosions=, how they break windows, 62
    in gas engines (illus.), 182
    of submarine mines (illus.), 34
    what happens in, 205

  =Explosives=, definition of, 205
    blasting gelatin, 206
    gun-cotton, 206
    nitroglycerine, 206

  =Eye=, of a submarine (illus.), 274

  =Eyes=, closed, walking with, 91
    hand quicker than, 376
    help brain in walking, 91
    in some pictures follow you, why, 36
    keeping body balanced, 91
    nature’s way of protecting, 38
    protecting with tears, 38
    sparkle when merry, why, 92
    why we can’t sleep when open, 92
    why we see stars when hit on, 268

  =Eye-wash=, tears as an, 38

  =Fabrics=, worsted, 85

  =Fahrenheit=, what is meant by, 221
    why so called, 221

  =Fastest= camera in the world, 25

  =Fathers and Mothers=, do plants have, 175

  =Federal Government=, grazing fee paid to, 82

  =Fertilization=, in birds, 179
    how corn plant fertilizes, 176
    of fishes, 177

  =Fight=, of Merrimac and Monitor, 32

  =Film=, before and after snapshot, 23
    sensitive, 23

  =Finger prints=, arch, (illus.), 520
    composite (illus.), 521
    of different people, 521
    enlargements of, 524
    how they identify us, 520
    impressions of orang-outang (illus.), 522
    loop (illus.), 520
    palmary impressions (illus.), 522
    specimen form of, record (illus.), 525
    spike that caught a criminal (illus.), 524
    thieves caught through their, 523
    thumb imprint on bottle (illus.), 523
    thumb impression on cash box (illus.), 523
    thumb mark on a candle (illus.), 523
    where first used, 522
    whorl (illus.), 521

  =Fingers=, why they hurt when cut, 143
    why we have ten, 142

  =Finger nails=, why we have, 142

  =Fire=, alarms when first used, 308
    first apparatus to fight, 308
    first fire department, 308
    first real, fire engine, 308
    gases put out, 37
    how man discovered, 289
    how man learned to fight, 208
    how man learned to make a, 289
    mark, of civilization, 290
    why it goes out, 37
    why is it hot? 401
    why put out by water, 222

  =Fire making=, drilling (illus.), 289
    drilling with bow string (illus.), 290
    drilling, two persons (illus.), 290
    first matches (illus.), 292
    flint and pyrites (illus.), 290
    flint, introduction of (illus.), 291
    plowing (illus.), 290
    pyrites (illus.), 290
    rubbing sticks together, 42
    sawing (illus.), 289
    steel and flint (illus.), 291
    tinder box (illus.), 291
    tinder box, pistol (illus.), 291
    with matches, 292

  =Firedamp=, 262
    explosion in safety lamp, 262

  =Firearms=, first crude efforts of, 45
    first real (illus.), 45
    fuse of, 45
    in early Chinese history, 44
    first trigger of, 45

  =Firing=, mortar, causes gas-rings, 27

  =First= man-carrying aeroplane, 128
    real telegraph, 421
    stringed musical instrument, 480
    telephone (illus.), 72
    telephone line, 72
    telephone switchboard (illus.), 74

  =Fishes=, how they are born, 177
    how they come to life, 177
    motion in swimming, 233
    what the eggs are, 177
    why they cannot live in air, 232

  =Flag=, made, how was American, 310
    made, when was American? 310

  =Flash pan=, early type, 45

  =Flaxseed oil=, what it is, 227

  =Flight=, of projectile, long, 30

  =Flint-lock=, invented in seventeenth century, 46
    invented by thieves, 46
    still in use in Orient, 46

  =Floor=, sounds through a, 79

  =Flour=, bolters (illus.), 465
    how made, 462
    purifying machine (illus.), 463
    sieves, 465

  =Flowers=, why they have smells, 176

  =Flying=, how birds learn, 178
    boat, wonderful (illus.), 133
    first Langley monoplane, 126
    first successful aeroplane (illus.), 126
    machine, first models, 127
    some of the men who helped, 126
    ten years of (illus.), 137

  =Flying boat=, fun in (illus.), 135
    gliding by, 137

  =Flying boat=, interior arrangement (illus.), 134
    monoplane type (illus.), 135
    six-passenger hull (illus.), 134
    speed of (illus.), 135
    the wonderful, 133
    views of (illus.), 133

  =Flying machines=, 126
    Bleriot flew in Europe (illus.), 129
    Curtis biplane in flight (illus.), 136
    Dr. Langley’s flying (illus.), 127
    early types of, 127
    first demonstrations, 130
    first flight in Europe with, 129
    first man-carrying aeroplane, 128
    first models, 127
    flying boat, 133
    flying boat, exterior arrangement, 134
    gliding experiments, 137
    government interest in, 138
    hull of flying boat, 134
    interesting governments in, 138
    Wright Bros., first flights, 130

  =Focus=, in eye, 22

  =Fog=, what it is, 105

  =Food=, how we learned to cook, 308

  =Foreign monoplanes=, some famous (illus.), 132

  =Forsythe, LL.D. J.=, inventor of the primer, 47

  =Freckles=, what makes them come, 125

  =Fuse=, for firearms in early history, 45

  =Funditor=, 42

  =Gas=, acetylene, 305
    definition, 348
    first structure to be lighted by, 302
    in coal mines, 262
    water, 305

  =Gas, illuminating=, Baltimore first city to use, 302
    carbon in, 302
    discovered, when, 302
    first American house to use, 302
    first practical demonstration of, 302
    generator house (illus.), 299
    holder (illus.), 298
    how it gets into jet, 302
    how it is purified, 303
    how made, 303
    how the meter works, 304
    hydrogen in, 302
    impurities removed from (illus.), 301
    jet, the story in a, 303
    made of, 302
    meter, description, 304
    purifying boxes (illus.), 301
    removing tar from, 300
    shaving scrubbers (illus.), 300

  =Gasoline engine= (illus.), 181, 182

  =Gases=, generated at gun muzzle, 27
    how expelled in gun ingot, 55
    hydrogen, 349
    nitrogen, 350
    oxygen, 349
    tendency to put out fire, 37

  =Gas-rings=, in firing motor, 27

  =Gatling=, inventor of guns, 310

  =Gelatine=, in photography, 23

  =Gestures=, talking by, 18

  =Ghosts=, what are they? 367

  =Glad=, why do we laugh when, 92

  =Glass=, why it cracks, 63
    how long known, 247

  =Glass, plate=, casting (illus.), 249
    commercial, 246
    plate and window glass compared (illus.), 252

  =Glass, plate, making=, annealing, oven, 249
    beveling, 247
    blanketing, 252
    clay mixing (illus.), 248
    clay trampling (illus.), 248
    clay used, 247
    grinding table, 250
    materials used in, 247
    mercury, 253
    nitrate of silver, 253
    pots (illus.), 248
    pots, drying of, 248
    pots, length of usefulness, 248
    silvering, 247
    skimming the pot (illus.), 249
    treading, 247

  =Glow-worm=, why does it glow? 231

  =Gold=, why is it called precious? 266

  =Gong=, why does it stop when it has been sounded, 78

  =Good luck=, why a horseshoe brings? 311

  =Graphite= in lead pencils, 468

  =Gravitation=, what is, 267

  =Gravity=, center of, in gun, 61

  =Gravity=, force of, 61

  =Greek fire=, in early history, 44

  =Growing=, why do we stop, 195

  =Gun=, action at muzzle, 27
    annealing a gun ingot, 57
    assembling of, 48-54
    arquebus of, 1537, 47
    barrels, erosion of, 35
    blow-holes, 56
    bore searcher, 59
    breech of a, 53
    discharges, force of, 33
    calibre of a, 53
    elastic limit, 58
    elongation, 58
    forging a (illus.), 52
    heat treatment, 58
    hoops of a, 54
    improvements in, 45
    ingot, calibre of, 55
    jacket of, 54
    length of a, 53
    liner of, 54
    life of, 35
    manufacture in America, 48
    measuring inside diameter (illus.), 59
    modern built-up (illus.), 54
    mold for ingot, 55
    muzzle of, 53
    pressure generated in a big gun, 54
    photography (illus.), 33
    piping, 56
    powder chamber of a, 53
    rifling (illus.), 60
    rifling of, 53
    shrinking pit, 59
    tensile strength of, 58
    factory, testing materials, (illus.), 50
    tube of, 54
    tube, how it is tempered, 57
    why called gatling, 310
    wire-wound, 54

  =Gun-barrels=, imported from England, 49
    resisting pressure of, 34

  =Gun-cotton=, in smokeless powder, 35, 206

  =Gunpowder=, Chinese probable discovers of, 44
    discoverer of, 44
    experiments by Schwartz, 45
    formula of Roger Bacon, 45
    ingredients in, 205
    manufactured in monasteries, 44
    what causes the smoke? 206
    smokeless, what made of, 206
    why some is fine and others large grained, 206

  =Gurgle=, in bottles, 63

  =Hail=, what causes, 124

  =Hair=, what causes baldness, 143
    why it don’t hurt when cut, 143
    why it keeps growing, 144

  =Hand bombards=, early types, 45

  =Hands=, shaking, why with the right, 231

  =Hansom=, why so called, 122

  =Have= plants fathers and mothers? 175

  =Heart=, why beats during sleep, 191
    why beats faster when scared, 191
    why beats faster when running, 191

  =Heat=, light wave changed into, 36
    why a nail gets hot when hammered, 230
    why some things are warm, 144
    how we obtain, 231

  =Hemp=, Manilla (illus.), 356

  =Hobson’s choice=, how originated, 311

  =Honey=, apiary in summer (illus.), 534
    how produced, 527
    worker comb (illus.), 532
    manner of using German bee-brush, 533
    finished product (illus.), 533
    frame (illus.), 535
    how to bump the bees off a comb (illus.), 533
    bee-hat (illus.), 535
    a study in cell-making (illus.), 532
    bee sting, can a, 536
    frame of bees (illus.), 535
    comb, how bees build, 536

  =Honey-bee=, poison-bag, 537
    egg of queen, under microscope (illus.), 529
    preparing for rearing, 531
    living on combs in open air, (illus.), 527
    the daily growth of larvæ (illus.), 532
    effect of a sting (illus.), 536
    worker-bee (illus.), 527
    what the queen-bee does? 528
    drone-comb (illus.), 532
    clipping queen bees wings (illus.), 533
    cucumber blossom with bee on it (illus.), 528
    queen-bee (illus.), 527
    the queen and her retinue (illus.), 529
    queen-rearing, 531
    queen-cells (illus.), 529

  =Honeymoon=, why do they call it a? 311

  =Horizon=, how far away is the, 245
    what is it, 244
    where is it, 244

  =Horse-power=, a, what it is, 256

  =Horseshoes=, why it is said to bring good luck? 311

  =Hot box=, cause of, 368

  =Houiller=, French gunsmith, 48

  =Houses=, concrete (illus.), 101

  =How= far does the air extend? 243
    is ammunition made (illus.)? 49
    does an arc light burn? 307
    are automobile tires made? 382
    does a honey bee live? 336
    does a bee make honey? 527
    do bees build the honey comb? 536
    does the honey bee defend itself? 536
    does honey develop in a comb (illus.)? 530
    do birds learn to fly? 178
    do birds find their way? 407
    does the blotter take up the ink of a blot? 18
    this book is bound, 578
    this book is made, 561
    the paper in this book is made, 561
    the pictures in this book are made, 581
    are bullets made? 51
    is an ocean cable laid? 429
    does a camera take a picture? 22
    is a cable dropped into the ocean (illus.)? 432
    are modern carpets made? 169
    is a carpet woven by machinery? 171
    is china decorated? 406
    is china made? 404
    is chocolate made? 392
    did the custom of clinking glasses in drinking originate? 232
    are cigars made? 517
    is cloth made from wool? 86
    did the coal get into the coal mines? 257
    does a coal mine look inside? 260
    do the cocoa beans grow (illus.)? 391
    is the color put on the outside of the pencil? 469
    is the honey comb made? 532
    are concrete roads built (illus.)? 103
    did man learn to cook his food? 308
    are concrete buildings made (illus.)? 100
    is woolen cloth dyed? 87
    big is the earth? 124
    much of the earth does the sun shine on at one time? 324
    does an elevator go up and down (illus.)? 396
    was electricity discovered? 333
    does the light get into the electric bulb? 305
    is the eraser put on a pencil? 469
    can an explosion break windows? 62
    explosions may occur on submarines, 278
    does the farmer use concrete (illus.)? 102
    do our finger prints identify us? 520
    did man learn to fight fire? 308
    did man learn to make a fire? 289
    are fishes born? 177
    was the flag made? 310
    is flour made? 462
    does a fly walk upside down? 454
    did men learn to fly? 126
    does the gas get into the gas jet? 302
    is illuminating gas made? 303
    is gas purified? 303
    is plate glass made? 246
    is plate glass ground? 250
    a wire-wound gun is made? 54
    was the first American gun made (illus.)? 47
    is a gun ingot made? 55
    do we find the length of a gun? 53
    is a gun tube tempered? 57
    do we obtain heat? 231
    the heel of a shoe is put on (illus.), 560
    did Hobson’s choice originate? 311
    far away is the horizon? 245
    does a key turn a lock (illus.)? 491
    does a spring lock work (illus.)? 492
    are lead pencils made? 467
    do the miners loosen the coal? 261
    is light produced, 230
    are magnets made? 335
    are matches made? 293
    are match boxes made? 294
    did man learn to send messages? 412
    does the meter measure the gas? 304
    can microbes spread through the body? 410
    are mirrors silvered? 522
    big is a molecule? 348
    did money originate? 455
    are moving pictures made? 369
    does the music get into the piano? 478-482
    did the word news originate? 312
    did a nod come to mean yes? 19
    did shaking the head come to mean no? 19
    are paints mixed? 228
    is a photograph developed? 23
    was the piano discovered? 479
    do plants breathe? 241
    do plants reproduce life? 175
    does the shield cut through the ground in tunnel building? 212
    are shooting shells photographed? 24
    shoes are made by machinery, 549
    shoe machinery was developed, 457
    is crude rubber secured? 377
    is rope turned and twisted? 358
    are rubber tires made? 378
    are modern rugs made? 169
    to splice a rope, 364
    do men go down to the bottom of the sea? 202
    did the sand get on the seashore? 108
    far back does the silkworm date? 109
    was silk introduced into Europe? 110
    are the silkworms cared for? 113
    do we know a thing is solid, liquid or gas? 348
    are sounds produced? 485
    fast does sound travel? 486
    can sound come through a thick wall? 79
    is the volume of sound measured? 242
    far does space reach? 256
    do the slate pickers work? 259
    does a captain steer his ship across the ocean? 407
    can a ship sail under water, 269
    is a submarine submerged? 270
    do sponges grow? 286
    do sponges eat? 287
    are sponges caught? 287
    are the stars counted? 241
    big is the sun? 141
    hot is the sun? 141
    is a steel pen made (illus.), 17
    did man learn to shoot, 40
    do we get wool off the sheep? 82
    is a stone thrown with a sling? 41
    are metallic and paper shells filled with powder? 50
    did man learn to talk? 18
    did the telephone come to be? 70
    fast does thought travel? 242
    does a telegram get there? 414
    did man learn to tell time? 313
    did man begin to measure time? 314
    did men tell time when the sun cast no shadows? 317
    is the time calculated at sea? 315
    is tobacco cultivated? 516
    is tobacco cured? 516
    was tobacco discovered? 512
    is tobacco harvested? 515
    is tobacco planted? 514
    is a tunnel dug under water? 208
    does water put fire out? 222
    is white lead made? 225
    are wires put under ground? 76
    did writing first come about? 11
    did the Chinese write? 13
    did the Monks do their writing? 14
    does a pen write? 18
    much does the wool in a suit of clothes cost? 83
    much wool does America produce? 82
    is wool taken from the sheep? 82
    is the yarn for carpets dyed? 170
    is oxide of zinc obtained? 226
    does the water get into the faucet? 501
    are the big water pipes laid? 504
    did the name Uncle Sam originate? 458

  =Human body=, wonders of the, 311

  =Hunting=, with the bow-and-arrow, 43

  =Hurt=, why we cry when, 93

  =Hydrogen=, what it is, 349

  =Hypo=, used in developing, 23

  =Impact=, of projectile from guns, 28

  =Ink=, how does a blotter take up? 18

  =Instruments=, artillery, testing, 24
    musical, 488
    optical, based on refraction, 38

  =Incandescent lamp=, development of, 306

  =Inside= of a mine planting submarine (illus.), 277

  =Iron=, cast, 265
    melts at, 35
    the most valuable metal, 265
    wrought, 265

  =Is= a moth attracted by a light? 288
    man an animal? 180
    the hand quicker than the eye? 376
    there a reason for everything? 200
    there a man in the moon? 400
    yawning infectious? 192

  =Jacket=, of a gun, 54

  =Japan= the natural home of the silk worm (illus.), 112

  =Kentucky rifles=, 45

  =Key=, how it works in a lock (illus.), 491

  =Knots=, different kinds of (illus.), 363
    what makes, in boards, 223

  =Lambs=, Siberian, in South Dakota (illus.), 80

  =Lamps=, first street light in America, 296
    the Clanny safety, 264
    did candles come before? 294
    earliest forms of, 295
    Edison’s first (illus.), 306
    incandescent carbon (illus.), 306
    incandescent, development of, 306
    incandescent, electric, when invented, 305
    French watch tower (illus.), 295
    Mazda (illus.), 306
    from Nushagak hanging (illus.), 297
    Pagan votive (illus.), 296
    Tantalum (illus.), 306
    street, when first used, 295
    chimney protects flame, 37
    coal miners and safety, 262

  =Lamp chimney=, why it makes a better light, 37

  =Langley, Dr. Samuel P.=, 1914 flight of aeroplane, 128

  =Languages=, why so many, 197

  =Lantern=, the first oil (illus.), 297
    the “Réverbère” (illus.), 297

  =Laugh=, when glad, why we, 92
    nerves, 93
    when tickled, why we, 93

  =Laughter=, reflex action, 93

  =Lead=, as used in making paint, 267
    in a pencil, 468
    why so heavy, 267
    as used in pipes for plumbing, 267

  =Leather=, how the hides are treated, 539
    treatment of hides, 538
    unhairing machine (illus.), 540
    hide house (illus.), 538
    tanning process, 539
    rolling room (illus.), 539
    tanning sole leather, 539
    how upper leather is tanned (illus.), 540
    disposing of waste material, 540
    wringers, 539
    tan yard (illus.), 539

  =Legs=, not same length, 91

  =Lens=, in the eye, 22

  =Leyden jar=, what it is, 332

  =Life=, beginning of, 174
    beginning of man’s, 174
    how plants reproduce, 175

  =Light=, attracting moths, 288
    glow-worms why they glow? 231
    how produced, 230
    lightning bugs, made by, 231
    where it goes when it goes out, 36
    what makes match, 198
    in mirror, 22
    in negative, 23
    rays, 36, 495
    broken rays of, 38
    rays, heat from, 36
    and refraction, 38
    speed of, 36, 140
    travels faster than anything in the world, 36
    surrounding earth, 38
    wave changed into heat, 36

  =Lighting=, arc, how does it burn, 307
    in America, first street (illus.), 296
    first oil lantern, 297
    electric, when introduced, 305
    first street light in Paris, 297
    gas tank, (illus.), 298

  =Lightning=, why it follows thunder, 140

  =Lightning bugs=, why they produce light, 231

  =Lignite=, found in coal mines, 262

  =Liner=, of a gun, 54

  =Linseed oil=, extraction of, 228
    what it is, 227
    where it comes from, 227

  =Liquid=, definition, 348

  =Living=, why do some people live longer, 199
    reproduction necessary why, 174
    reproduction of, in birds, 179
    reproduction of, in fishes, 177

  =Loading= machines in powder factory, 50

  =Lobsters=, red, what makes them, 245

  =Lock=, cylinder (illus.), 492
    how a key turns a (illus.), 491
    how key changes are provided (illus.), 491
    how a spring lock works (illus.), 492
    master-keyed cylinder (illus.), 492
    what happens when the key is turned? (illus.), 491
    what happens when the knob is turned? (illus.), 491

  =Locomotives=, boiler of articulate type (illus.), 440
    boiler of (illus.), 442
    cab of (illus.), 442
    cylinders description of, 441
    low pressure cylinders of (illus.), 441
    electric, newest (illus.), 443
    one of the largest (illus.), 440
    signal tower, latest (illus.), 444
    stoker, automatic (illus.), 443
    water tank (illus.), 444

  =Lodestone=, what it is, 327

  “=Long Bow=,” in Sherwood Forest (illus.), 42

  =Loom=, cloth making machine, 86

  =Magnet=, breaking iron (illus.), 330
    electro (illus.), 326, 328, 335
    electric lift (illus.), 326
    experiments with, 327
    great lifting by (illus.), 330
    how made, 335
    what makes it lift things? 326
    wonders performed by, 326
    work it can do (illus.), 328

  =Man=, writing, how man learned, 11
    counting himself, 19
    is he an animal? 180

  =Matches=, are they poisonous? 294
    first, 292
    how made, 293
    lucifer (illus.), 292
    making by machinery, 293
    modern safety (illus.), 292
    oxymuriate (illus.), 292
    promethean (illus.), 292
    what we would do without, 292
    when first used (illus.), 292

  =Match-lock=, of early firearms, 45

  =Melting= of iron, 35

  =Men= who made the telephone, 70

  =Mercury=, fulminate of, 49

  =Merrimac and Monitor=, fight of, 32

  =Merry=, why eyes sparkle when, 92

  =Messages=, how men learned to send, 412
    Indian smoke signals, 412
    marathon runner by (illus.), 413
    pony telegraph (illus.), 413

  =Messenger boy=, how to call a (illus.), 414
    the first (illus.), 413

  =Metal=, what is a, 265
    what is the most valuable? 265
    why we use for coining, 456

  =Meter=, description of gas, 304
    how it measures gas, 304

  =Milk=, does thunder sour? 196

  =Milky way=, why is it called, 255
    what is, 255

  =Mine cars= (illus.), 260

  =Mines=, clearing channel of buoyant, 283
    exploding submarine, 34
    planting submarine, inside of (illus.), 277
    workers that never see daylight, 258

  =Mirror=, collects rays of light, 22
    reflection in, 22
    reflects rays of light, 22

  =Mirrors=, beveling (illus.), 251
    how made, 251
    how silvered, 252
    polishing, 251
    roughing, 251
    silvered with mercury, 253
    silvering mirror plates (illus.), 252

  =Molecule=, how big is a, 348
    what is a, 348

  =Monasteries=, where gunpowder was manufactured, 44

  =Money=, how originated, 455
    metallic forms of, 456
    who made the first cent, 458
    who originated, 455
    why do we need, 455
    why gold and silver are best for coining, 457

  =Monitor and Merrimac=, fight of, 32

  =Monks=, making gunpowder, 44

  =Monoplane=, flying boat (illus.), 135
    German (illus.), 132
    over Mediterranean (illus.), 132

  =Moon=, why it travels with us, 399
    the man in the, 400

  =Morse, S. B.=, inventor of telegraph, 420

  =Mortars= (illus.), 26

  =Mothers and Fathers=, do plants have, 175

  =Moths=, attracted by light, 288
    emerging from cocoon (illus.), 117

  =Motion= bodies, swiftest, 25

  =Motion=, is train harder to stop than start? 223
    of light, 140
    of sound, 140
    perpetual, 61
    perpetual, in mechanics, 240

  =Motors=, gas, used in aeroplanes, 130

  =Mountains=, what made them, 401

  =Moving pictures=, Board of Censors, 373
    developing room (illus.), 372
    drying room (illus.), 373
    continuous movement of film, 376
    exact size of film, 370
    first camera, 375
    first exhibited at studio, 372
    how made, 369
    how freak pictures are made, 376
    negative, stock, 370
    negative, perforated, 370
    “Pigs is Pigs” (illus.), 374
    rehearsing (illus.), 371
    scenario (illus.), 374
    staging, 371
    taking a (illus.), 373

  =Mulberry trees=, food for silk worms (illus.), 112

  =Mules and drivers= (illus.), 258

  =Multiple switchboard= of telephone, 69

  =Music=, harp, 479
    lyre, 479
    note, what it is, 490
    what pitch is, 489
    what is, 478

  =Musical talking machines=, 490

  =Muzzle=, of a big gun, 53

  =Muzzle-loaders=, in Civil War, 47

  =Nails=, why they get hot when hammered, 230

  =Names=, of people, 20

  =Nature=, protecting eyes, ways of, 38

  =Navigating= on bottom of sea, 283

  =Negative= in photography, 23

  =Nerves=, sensory, receive impression, 93
    transmitting impression, 22

  =News=, how did the word originate? 312

  =Nightmare=, cause of, 367

  =Nitrogen=, what it is, 350

  =Ocean=, why is it blue? 219
    what makes it green? 219
    why don’t water sink in? 219
    where did all the water in, come from? 218
    where is water at low tide, 219

  =Of= what use is my hair? 143

  =Of= what use are pains and aches? 410

  =Oil baths=, for gun (illus.), 57

  =Oil cake=, from linseed, 228

  =Oil=, palm olive, in soap, 411

  =Omniscope=, of submarine boat, 271

  =Onions=, make tears, 38
    bad effect of on eyes, 38

  =Operatives=, in powder factory, girls as, 49

  =Optical instruments=, based on refraction, 38

  =Organic matter=, what it is, 174

  =Origin of cement=, 95
    of counting in tens, 19
    names of people, 20
    of nodding to indicate yes, 19
    of shaking head to indicate no, 19
    of turnpike, 104

  =Oxide of zinc smelter= (illus.), 227
    how obtained, 226

  =Oxygen=, what it is, 349
    in air, 37

  =Pain=, of what use is, 410
    what it is, 244

  =Paint=, care of, story in, 224
    how mixed, 228
    uses of, 224
    what used for, 224

  =Paint manufacturing=, colors, what makes different, 229
    buckles before corrosion (illus.), 225
    buckles after corrosion (illus.), 225
    buckles placed in stacks (illus.), 225
    buckles taken from stacks (illus.), 225
    first step in making (illus.), 224
    lead buckles making (illus.), 224
    lead, white, how made, 224-225
    lead white used in, 224
    grinding lead in oil (illus.), 228
    washing the lead (illus.), 226
    mixing, 228
    where paints are mixed (illus.), 228
    linseed oil, where obtained, 227
    pressing oil from flaxseed (illus.), 228
    removing oil cake from press, 228
    sulphur roasting furnace (illus.), 226
    zinc smelter (illus.), 227
    oxide of zinc, how made, 226

  =Paper=, earliest forms of, 14
    sensitive in photography, 23
    shells, inspection of (illus), 49
    papyrus, the first, 14

  =Papyrus=, invention of, 14

  =Patents=, of original telephone, 73

  =Peat=, as a fuel, 262

  =Pen=, first metallic (illus.), 15
    first steel (illus.), 15
    first metallic pen, how made, 15
    how it writes, 18
    invention of the, 15

  =Pencils, “lead”= where from, 466
    eraser is put on, 469
    making description of (illus.), 467
    who made the first? 466

  =Periscope=, description of, 275
    how we look through a (illus.), 276
    mirror of, 275

  =Perpetual motion=, nearest approach to, 240
    is it possible? 61

  =Persian rug=, antique (illus.), 167
    how made, 167
    imitation (illus.), 167
    Kurdistan (illus.), 167
    where best are made, 167

  =Photographs=, of projectiles, 25

  =Photography=, resultant from experiments with mirror, 22

  =Piano=, pitch, 489
    finishing (illus.), 484
    why not more than seven octaves, 480
    Dulcimer (illus.), 479
    spinet (illus.), 480-481
    note what it is, 490
    sounding board, 488
    tuning, (illus.), 484
    building case around (illus.), 483
    how the music gets into the, 482
    clavichord (illus.), 480
    instruments, musical, 488
    strings, fastening on (illus.), 482
    psaltery, 480
    sound box, the first, 479
    who made the first, 478
    hammers (illus.), 483
    action regulation (illus.), 484
    virginal (illus.), 480-481
    first (illus.), 478
    tuning fork, 488
    polishing (illus.), 484
    sounding board, putting on the (illus.), 482
    how discovered, 479
    lyre, 479
    octave, 480
    harpsichord (illus.), 480-481

  =Pickers=, boy, slate (illus.), 259

  =Pictures=, with a fast camera, 39
    moving, how made, 369
    size of moving film, 370
    never seen by the human eye, 31
    taken in one five-thousandth of a second, 31

  =Pin money=, why they call it? 231
    how name originated, 231

  =Pistols=, invented in Pistola, Italy, 46

  =Plants=, corn, why it has silk? 176
    do father and mother plants live together, 176
    how they eat, 511
    how they reproduce, 175
    why do flowers have smells? 176
    why they produce leaves, 175

  =Plate glass=, (illus.), 246

  =Portland Cement=, why called, 95

  =Powder=, filling shells, 50
    gun-cotton in smokeless, 35
    secret of smokeless powder, 35
    smokeless, 35
    in submarine mines, amount of, 34

  =Pressure=, generated in bore of a big gun, 54
    inside of a gun at discharge, 33
    in gun-barrel, resistance of, 34
    of light, on scales, 37

  =Primer=, invented by, 47

  =Prof. Bell’s= vibrating reed (illus.), 71

  =Projectiles=, photographs of, 25
    arrival at target, 24
    clear of smoke-zone (illus.), 30
    smoke-zone, emerging from (illus.), 29
    height in air from mortar, 30
    impact of, from guns, 28
    leaving gun muzzle (illus.), 27
    travel faster than sound, 32
    velocity of, 33
    viewed in transit, 33
    weight of, 53

  =Proving grounds=, for big guns, (illus.), 53

  =Pyro=, used in developing, 23

  =Quarry=, cement (illus.), 96

  =Quill the=, in writing (illus.), 14

  =Quills=, raising geese for, 14

  =Rails, steel making=, blast furnace (illus.), 234
    blooming mill (illus.), 237
    crane, carrying ingot, (illus.), 236
    length of, 238
    mixer (illus.), 234
    molten steel, pouring (illus.), 236
    open hearth furnace (illus.), 235
    pouring side of open hearth furnace, 235
    shrinkage of, 238
    soaking pit (illus.), 236
    temperature in furnace, 235

  =Rain=, where it goes, 222
    why it freshens the air, 222

  =Rainbow=, cause of, 253
    colors in, what makes? 254
    ends of, 254

  =Rays=, change their course, 38
    heat from light, 36
    of light, 36
    Roentgen, 307

  =Rays-X=, what are they? 307

  =Reason=, is there one for everything? 200

  =Reed=, the (illus.), 12

  =Reflection=, in mirror, 22, 91

  =Refraction=, changing light rays called, 38
    of light, 38

  =Reproduction=, of life, in birds, 179
    in fishes, 177
    in plants, 175
    why we must have, 174

  =Rifle=, Kentucky, 45
    kick of, 47
    modern automatic, 47
    over-loading, 47
    wheel-lock (illus.), 46

  =Rifling=, causes rotation of projectile, 32
    a big gun (illus.), 60
    of a gun, 53
    invented in Austria, 46

  =Roads=, concrete (illus.), 103

  =Roentgen Rays=, 307

  =Rope=, breaker (illus.), 360
    compound laying machine (illus.), 361
    cross-section, 362
    draw frame (illus.), 360
    drying fiber, 354
    Egyptian kitchen (illus.), 354
    Egyptians making (illus.), 353
    preparing the fiber in (illus.), 359
    four-strand (illus.), 362
    hackling, 354
    hemp (illus.), 356
    hemp in warehouse (illus.), 356
    knots, 363
    lengths, standard, 362
    oiling in manufacture, 356
    long made by hand, 354
    machine (illus.), 358
    opening bales of fiber (illus.), 359
    preparation room (illus.), 359
    scraping fiber (illus.), 354
    sliver formation of (illus.), 360
    spindles, 355
    spinning after turn, 355

  =Rope spinning=, after turn, 355
    foreturn, 355
    splicing (illus.), 364
    spreader (illus.), 360
    stakes, 355

  =Rope walk=, modern (illus.), 357-358
    old-fashioned (illus.), 355

  =Routine=, of a telephone call (illus.), 68

  =Rubber=, automobile tires, 382
    biscuit, 377
    blisters, 379
    blow holes, 379
    breaker-strip, 384
    calendering, 381
    castilloa, 387
    cement, 381
    crude, 377-378
    curing room, 382-383
    dryer, 379
    fabric, 384
    furnishing pneumatic tires (illus.), 386
    gathering (illus.), 377
    how secured, 377
    how are inner tubes made, 385
    marketing balls of, 377
    mixing, 379
    Para, 387
    pneumatic tires, 383
    pure, why not used, 380
    spreading, 381
    spreader room (illus.), 383
    tapping (illus.), 377
    tire building machines (illus.), 385
    tires, how made, 378-379-380
    tread laying room, 384
    tubes, inner, how made, 385
    vulcanizing, 384
    washing, 378
    wild, what is, 387
    why not used pure, 380
    wrapping room, 386

  =Rugs=, designs imitated by machinery, 168
    Persian (illus.), 167
    Persian, how made, 167
    Persian, imitation, 167
    Persian Kurdistan (illus.), 167
    Persian, where best are made, 167
    Tabriz, reproduction (illus.), 168
    weaving by machine (illus.), 171

  =Rug manufacturing=, carding machine (illus.), 170
    examining and repairing (illus.), 173
    packing for shipment (illus.), 173
    processes, 169-170
    weaving by machinery (illus.), 171
    wool sorting, 170

  =Sadness=, cause of tears, 38

  =Salt=, beds, 493
    chemical name of, 493
    in water, 351
    mines, 493
    Salt Lake, 493
    soda, 493
    supply for United States, 493
    wells, 493
    where it comes from, 493

  =Scales=, pressure of light on, 37

  =School slates=, where they come from, 495

  =Score=, origin of, 26

  =Scouring=, wool (illus.), 85

  =Scouring and weaving=, in making woolen cloth (illus.), 88

  =Screens=, in shot tower, 51

  =Sea=, diver, 202
    how men go down to the bottom of, 202
    navigating on bottom of, 283
    time calculated on the, 315
    what the bottom looks like, 202
    what makes it roar, 401

  =Second=, reckoning in millionths of a, 25
    pictures taken in one five-thousandth of a, 31

  =Seeds=, why plants produce, 175

  =Seeing=, why we cannot see in dark, 91

  =Sensation=, of sight, 22

  =Sensitive=, paper, 23

  =Service=, military, U. S., 24

  =Shadows=, cause of, 495

  =Shell=, sounds in a, 79

  =Shells=, filling with powder, 50
    inspection of metallic (illus.), 49
    putting metal heads on paper, 50
    wad-paper in making, 50

  =Sheep=, coming out of forest (illus.), 82
    first in America, 80
    fleece packing, 82
    how much wool does a sheep produce? 83
    how wool is taken from the, 82
    how taken care of, 82
    how we get wool off of, 82
    industry in America, 80
    industry in the colonies, 81
    industry in the west, 81
    number in the west, 81
    shearing, 82
    shearing machines, 82
    wool-producing, 83
    why sheep precede the plow in civilizing a
    country, 81

  =Shield driving=, air lock bulkhead (illus.), 210
    caulking the joints (illus.), 214
    description of airlocks, 213
    erector at work (illus.), 214
    erector (illus.), 210
    at end of journey (illus.), 216
    grommetting the bolts (illus.), 214
    grouting (illus.), 214
    how it cuts in tunnel building, 212
    how they meet exactly (illus.), 215
    in tunnel building (illus.), 208
    key plate (illus.), 214
    curves around (illus.), 216
    models of Penna. R.R. tunnel shields (illus.), 212
    rear end in tunnel building (illus.), 210
    tunnels, front view (illus.), 209

  =Ship=, how does a captain steer his, 407
    how can it sail under water? 269

  =Shoes=, Amazeen skiving machine, 550
    assembling machine (illus.), 552
    automatic heel loading and attaching
    machine (illus.), 560
    automatic leveling machine (illus.), 559
    automatic sewing machine, 555
    American made, 547
    ancient and modern forms of sandals, (illus.), 543
    ancient sandal maker (illus.), 541
    beginning of a shoe (illus.), 549
    boot developed from the sandal, 544
    boots (illus.), 546
    channel cementing machine (illus.), 558
    channel laying machine (illus.), 559
    channel opening machine (illus.), 558
    Crakrow or peaked (illus.), 544
    which church and law forbade (illus.), 544
    description of ancient sandal (illus.), 542
    dyeing out machine, 551
    different parts come together, 551
    duplex eyeletting machine, 550
    edge trimming machine (illus.), 560
    Ensign lacing machine, 551
    evolution cf the sandal to the shoe (illus.), 542
    first machine for making shoes, 545
    hand method lasting machine (illus.), 553
    heel breasting machine (illus.), 560
    heel trimming machine (illus.), 560
    ideal clicking machine, 550
    Inseam trimming machine (illus.), 556
    insole tacking, 551
    lasting machine (illus.), 553
    loose nailing machine (illus.), 559
    success of McKay machine, 547
    machine that forms and drives tacks, 554
    machines which punch the soles of, 559
    my lady’s slippers (illus.), 548
    placing shank and filling bottom, 556
    planet rounding machine, 551
    power tip press, 550
    pulling over machine (illus.), 552
    putting the ground cork and rubber cement in, 556
    rolling machine, 551
    rounding and channelling machine (illus.), 557
    sewing the sole on, 558
    slugging machine (illus.), 560
    sole laying machine (illus.), 557
    Summit splitting machine, 551
    upper stapling machine (illus.), 554
    upper trimming machine (illus.), 554
    welt and turned shoe machine (illus.), 555
    welt beating and washing machine, 556
    welt sewing machine, 551
    what was the first foot covering like? 541
    “whipping the cat,” 545
    who made the first shoe in America? 545
    work performed by heeling machine (illus.), 560

  =Shooting tests= (illus.), 48

  =Shotguns=, assembling of, (illus.), 48

  =Shot pellets=, 51

  =Shrinking=, pit for big gun, 59

  =Shuttle=, In weaving wool, 86

  =Siberian lambs=, in South Dakota (illus.), 80

  =Signs=, talking by, 18

  =Silica=, mine (illus.), 247

  =Silk=, 109
    called “bomby-kia,” 110
    caring for young worms, 113
    culture, 110
    drying skeins of, 119
    dyeing, 121
    first step in manufacture, 119
    first used, 109
    hatching eggs, 113
    introduction of into Europe (illus.), 110
    number of cocoons in pound of, 117
    manufacture of, 119
    method of reeling, 113
    moths depositing eggs (illus.), 112
    preparing cocooning beds, 112
    reeling silk from cocoon (illus.), 118
    spinning (illus.), 120
    thread made uniform (illus.), 120
    threads ready for the weaver, 121
    twisting (illus.), 120
    use of, 109
    water-stretcher (illus.), 121
    winding (illus.), 119

  =Silk manufacture=, doubling frames, 120
    spinning, 120
    twisting, 120

  =Silk moth=, description of 114

  =Silkworm=, age, 115
    first breeder of, 109
    chrysalis (illus.), 114
    cocoon, 115
    cocoon, beginning of (illus.), 116
    cocooning bed (illus.), 112
    description of, 114
    domestication of, 111
    eating (illus.), 115
    female moth (illus.), 114
    how cared for, 113
    how it eats, 115
    home of, 112
    eggs, how imported, 111
    hatching the eggs (illus.), 113
    how he does his work, 114
    larvæ of, (illus.), 114
    motions of head in spinning, 115
    molting season, 115
    moths emerging from cocoon (illus.), 117
    male moth (illus.), 114
    mulberry branches for (illus.), 112
    one of the world’s greatest wonders, 116
    preparing for making cocoon (illus.), 116
    reared, how they (illus.), 115
    shedding old skin, 115
    spinneret of the, 115
    spinning cocoon, 115
    wild, 109

  =Silver=, definition of, 207
    use, history of, 207
    why does it tarnish, 266

  =Silver bromide=, in photography, 23

  =Skins=, used for clothing, 80

  =Sky=, will it ever fall? 255
    why is it blue? 253

  =Soap=, lye in, 411
    palm olive oil in, 411
    what made of, 411

  =Soda=, Leblanc process, 494
    Solvay process, 494
    where we get, 494

  =Solids=, definition, 348

  =Some= wonders of the human body, 311

  =Sound=, deadening of, 79
    first over a wire, 71
    how measured, 242
    how produced, 485
    speed of, 140-486
    travels through air slowly, 31
    in a sea shell, 79
    what is, 78-485
    waves, 79
    waves, length of, 487
    where comes from, 78

  =Slate pencil=, why cannot write on paper with, 18

  =Sleep=, where are we when, 365
    with eyes open, why we cannot, 92
    ghosts, 367
    why heart beats during, 191
    why we go to, 365
    restless, 92

  =Sling=, man in action (illus.), 41
    how first made, 41

  =Slings=, and their drawbacks, 42

  =Slow match=, of early firearms, 45

  =Smells=, why do flowers have, 176

  =Smoke-cone=, in gun-firing (illus.), 28

  =Smokeless powder=, 35

  =Smoke-rings=, hard as steel, 27

  =Smoke signals=, of Indians, 412

  =Smoke-zone=, in gun firing, 111

  =Sneezing=, what makes us, 194
    why do we, 194

  =Snowflakes=, what makes them white? 409

  =Space=, extends, how far, 256

  =Sparkle=, when merry, why eyes, 92

  =Spear=, as a weapon, 42

  =Specific gravity=, meaning of, 268

  =Speed=, of light, 36

  =Spinneret=, of the silkworm, 115

  =Spinning wheel=, in making cloth from wool, 81

  =Sponge=, capillary attraction of, 18

  =Sponges=, breeding time of, 286
    how do they grow? 286
    how they eat, 287
    how they are caught, 287
    where they come from? 286

  =Stable=, underground (illus.), 158

  =Stars=, counted in photograph, 223
    do they shoot down? 255
    how counted, 241
    how many there are, 223
    photographed, 223
    what makes them twinkle, 38

  =Steamship=, beginning of (illus.), 337
    cross-section, 346
    building of a (illus.), 337
    cradle of a, 338
    double bottom, 339
    end to end section, 346-347
    funnel (illus.), 345
    gantry (illus.), 338
    hull (illus.), 341
    hull before launching (illus.), 340
    inside of (illus.), 346-347
    launching of a (illus.), 340
    launching machinery (illus.), 341
    ready to launch (illus.), 340
    plates (illus.), 339
    ribs (illus.), 338
    skeleton (illus.), 339
    turbine, weight of, 344
    turbine (illus.), 344

  =Steel pen=, how made, 16

  =Steel rail making=, blast furnace (illus.), 234
    Blooming mill and engine (illus.), 237
    dump buggy, 237
    crane, carrying ingot (illus.), 236
    ingot, 237
    ingot becomes a rail (illus.), 238
    mixer (illus.), 234
    molten steel being poured into ladle (illus.), 236
    open-hearth furnace (illus.), 235
    furnace, pouring sides of an open hearth (illus.), 235
    iron, purification of, 235
    soaking pit (illus.), 236
    furnace, temperature in, 235

  =Stick=, why it bends in water, 38
    making a fire with, 42

  =Stockings=, where it goes when the hole comes, 64

  =Stone-throwing=, 41

  =Stones=, where they come from, 494

  =Story= in an automobile, 181
    in a loaf of bread, 460
    in a book, 561
    in a building foundation, 496
    in a cablegram, 428
    in a barrel of cement, 95
    in a stick of chocolate, 388
    in a suit of clothes, 80
    in a lump of coal, 257
    in a bale of cotton, 470
    of a cup and saucer, 404
    of the deep sea diver, 203
    in an electric light, 305
    in an elevator, 395
    in a finger print, 520
    in a flying machine, 126
    in a gas jet, 303
    in a gun, 40
    in a honey bee, 526
    in a magnet (illus.), 326
    in a lead pencil, 466
    in lighting a fire, 289
    in a lock, 491
    in a can of paint, 224
    in a pen, 11
    in a piano, 478
    in a photograph, 22
    in “Pigs is Pigs” (illus.), 374
    in a pipe and cigar, 512
    in a railroad engine, 440
    in a coil of rope, 353
    in a ball of rubber (illus.), 378
    in a rug, 167
    in a pair of shoes, 541
    in a steel rail (illus.), 234
    in a submarine boat (illus.), 269
    in a lump of sugar, 145
    in a telegram, 412
    in the telephone, 65
    in a time piece, 313
    in a tunnel, 208
    in a drink of water, 501
    in a window pane, 246
    in the wireless, 455
    in a yard of silk, 109
    in a piece of leather, 538

  =Stringed instruments=, the first, 480
    discovery of, 479

  =Stretching=, why do we, 192
    what happens when we, 193

  =Stylus=, iron, 13
    the in writing (illus.), 11

  =Submarine=, accidents and their causes, 278
    air and how it may become poisonous, 278
    buoyancy of, 270
    “Bushnell’s Turtle,” 280
    cargo, recovering of, 285
    clearing a channel of buoyant mines (illus.), 283
    development of, 280-281
    divers’ compartment, 270
    equilibrium, 270
    explosions, 278
    first practical (illus.), 271
    gas, explosion of, 278
    “G-1” (illus.), 272
    Holland, 282
    how we look through a periscope (illus.), 276
    hydroplanes on, 270
    hydroplane, 282
    ice, under (illus.), 279
    inside of a (illus.), 272
    lens, of periscope (illus.), 276
    living quarters (illus.), 285
    mice on, 278
    mine planting inside of (illus.), 277
    Omniscope, 271
    one of the first practical, 271
    “Proctor,” first practical, 271
    “Proctor” submerged (illus.), 271
    periscope top of (illus.), 276
    rudder, horizontal, 270
    sailing close to surface (illus.), 273
    seeing in all directions at once, 276
    Simon Lake, American inventor of, 282
    steadiness of (illus.), 273
    under the ice (illus.), 279
    submergence, 270
    water pressure on, 270
    who made the first, 280

  =Submarine boat=, “Argonaut the First” (illus.), 269-282
    “Argonaut Junior” (illus.), 269-282
    who made the first, 280

  =Submarine mines=, amount of powder used, 34

  =Sugar=, carbonatation station (illus.), 150
    chemical laboratory in factory (illus.), 149
    circular diffusion battery in factory (illus.) 149
    filter presses (illus.), 150
    how taken from beets, 150
    sulphur station (illus.), 150
    washing the beets, 149

  =Sugar factory=, carbonatation station (illus.), 150
    chemical laboratory in (illus.), 149
    circular diffusion battery (illus.), 149
    filter presses (illus.), 150
    sulphur station (illus.), 150

  =Suit=, cost of wool in a, 83

  =Sulphite of soda=, used in developing, 23

  =Sun=, distance from earth, 141
    revolving on its axis, 511

  =Sun-dial= (illus.), 315
    in determining noon (illus.), 316
    concrete (illus.), 101

  =Sunlight=, effect on balance, 37

  =Sunset=, cause of colors in, 253

  =Swallowing=, what happens when we, 195

  =Swimming=, why man must learn, 125

  =Switchboard=, telephone, 69
    back of a, telephone (illus.), 69
    telephone, the first (illus.), 74

  =Talking=, how man learned talking, 18
    signs and gestures, 18

  =Talking machines=, 490

  =Target=, floating, 31
    Never seen by men firing mortar, 29
    projectile, arrival at, 24

  =Tears=, caused by onions, 38
    as an eye-wash, 38
    run along channel, 38
    where they come from, 94
    where they go, 94

  =Teeth=, why they are called wisdom, 125
    why they chatter, 218

  =Telegram=, how it gets there, 414
    story in a, 412

  =Telegraph=, cables (illus.), 424
    code, 419
    calling a messenger, 414
    waiting calls (illus.), 414
    arrival at destination (illus.), 417
    duplex, 417
    electric, 420
    electric, first suggestion of, 420
    inventor of, 420
    two men inventors of, 421
    instruments, 425
    instruments, first sending (illus.), 426
    instrument, sending, 418
    key, modern (illus.), 427
    key, a later, 427
    key, sending (illus.), 418
    line, first, 422
    messenger receives message (illus.), 415
    messages, number sent in a day, 417
    multiplex, 417
    operating room (illus.), 423
    the pony (illus.), 413
    quadruple, 417
    Wheatstone, receiver (illus.), 425
    Wheatstone sender (illus.), 425
    receiving operator (illus.), 416
    relay, the first (illus.), 426
    relay, modern (illus.), 427
    recording apparatus first (illus.), 426
    recording instrument improved, (illus.), 427
    repeater room (illus.), 424
    sending operator (illus.), 416
    sounder, modern (illus.), 427
    main switchboard (illus.), 423
    automatic typewriter (illus.), 425

  =Telephone=, apparatus, 65
    birthplace of (illus.), 70
    cost of number in use (illus.), 77
    display board (illus.), 65
    discovery of, 71
    feeding cable into duct (illus.), 76
    first outdoor demonstration, 75
    how an emperor saved the, 73
    forces behind your, 77
    modern distributing frame (illus.), 75
    line, the first, 72
    line lamp, 66
    pilot lamp, 66
    from bottom of ocean, 203
    operator, 67
    breaking up the asphalt pavement (illus.), 76
    a cable trouble (illus.), 76
    call routine of (illus.), 68
    beginning of service, 75
    the first switchboard, 72
    laying multiple duct subway (illus.), 76
    first practical commercial test of telephone, 75
    how wires are put underground (illus.), 76
    nine million in use, 75
    the first words over, 74

  =Tens=, counting in, 19

  =Test=, of big gun (illus.), 53

  =Testing=, materials and products in gun factory (illus.), 50
    artillery instruments, 24

  =Tests=, shooting (illus.), 48

  =Things=, to know about a big gun, 53

  =Throats=, making sounds with our, 78

  =Thread=, silk, made uniform (illus.), 120

  =Thunder=, why it precedes lighting, 140
    does it sour milk? 196

  =Tickled=, why we laugh when, 93

  =Tides=, where does water go at, low, 219

  =Time=, age of clocks, 391
    blacksmith’s clock (illus.), 320
    first modern clock, 319
    hour-glass (illus.), 317
    time-boy of India (illus.), 317
    where the day changes, 325
    where is the hour changed? 325
    clock in Independence Hall (illus.), 323
    clock in New York City Hall (illus.), 323
    largest clock in the world, 321
    machinery which runs a big clock (illus.), 322
    how man measured, 314
    modern clock, description of (illus.), 319
    primitive twelve-hour clock, 318
    water clocks for, 317
    water-clock (illus.), 318
    man’s first divisions of, 314
    what it is, 313
    three great steps in measuring, 316
    first methods of telling (illus.), 313
    in New Testament, 314
    sun-dial (illus.), 315
    sun-dial in determining noon, 316
    calculated at sea, 315
    tower of the winds (illus.), 318
    how told when sun casts no shadows, 317

  =Tin=, why used for cooking utensils, 267

  =Tobacco=, barn, 515
    growing crop, care of, 514
    growing under cheesecloth (illus.), 512
    grown in Cuba, 513
    cultivation of, 516
    curing of, 515
    cigars, how made, 517
    how discovered, 512
    field (illus.), 515
    figures about, 519
    filler, 518
    fertilization, 514
    where it comes from, 512
    shade growing, 517
    where does it grow, 512
    harvesting, 515
    Havana, where grown, 513
    origin of name, 512
    planting, 514
    seed beds, 514
    first care in selection, 518
    strippers, 518
    bulk sweating, 516
    wrappers, 518
    butter worm, 514

  =Toes=, why we have ten, 142

  =Toothache=, what good can come from? 410
    cause of, 410

  =Torches=, used in battles, 44

  =Tow-line=, of floating target, 31

  =Trains=, why harder to stop than start, 223

  =Transparent=, why some things are, 350

  =Trees=, found in coal, 261

  =Tube=, of a gun, 54

  =Tunnels=, accidents in, 218
    causes of accidents, 218
    accuracy of engineering, 215
    airlocks, description of, 213
    operation of airlocks, 213
    compressed air method, 211
    the bends, 213
    bends, the danger of, 213
    bends, the symptoms of, 213
    dangers in building, 218
    grommetting the bolts, (illus.), 214
    borings in ground (illus.), 216
    airlock bulkhead (illus.), 210
    how built, 209
    driving shield rear end of in tunnel building (illus.), 210
    caissons in Hudson tunnels (illus.), 217
    curves, how made (illus.), 216
    how shield cuts through, 212
    how dug under water, 208
    erector (illus.), 210
    erector at work (illus.), 214
    grouting (illus.), 214
    inventor of shield method, 209
    inventor of compressed air method, 211
    caulking the joints (illus.), 214
    making joints water tight, 214
    at end of journey (illus.), 216
    land end of Hudson tunnels (illus.), 217
    danger of leaks, 213
    result of leaks (illus.), 213
    concrete lining (illus.), 216
    key plate (illus.), 214
    diagrams of driving shield (illus.), 208
    biggest ever built by shield method, 209
    rear end of driving shield (illus.), 210
    driving shield front view (illus.), 209
    how the shields meet exactly (illus.), 215
    models of Penna RR. tunnel shield (illus.), 212

  =Turbine=, how it works (illus.), 344

  =Twinkle=, what makes stars, 38

  =Twinkling stars=, due to interference, 38

  =Types= of cartridges (illus.), 49

  =Umbrella=, who made the first, 312
    who carried the first, 312

  =Uncle Sam=, how name originated, 458

  =Undercutting= with compressed air machine (illus.), 261

  =Vault= of telephone cables (illus.), 67

  =Velocity= of a projectile, 53

  =Waking=, why we wake up, 365

  =Walking=, difficult to, straight with eyes closed, 91
    why cannot babies walk as soon as born, 180

  =Wall=, sounds through a thick, 79

  =Water=, aqueduct (illus.), 505
    Ashokan Reservoir (illus.), 502
    boiling-point of, 35-220
    drinking, where does it come from, 501
    hard, 221
    how is a big dam built, 502
    Hudson River siphon (illus.), 507
    in ocean where it came from, 218
    pumping station (illus.), 503
    real source of the (illus.), 506
    regulating chamber (illus.), 506
    reservoir, 503
    soft, 221
    as standard in measuring specific gravity
    solids, 268
    what made of, 348
    what makes it boil, 220
    what makes water shoot in air, 198
    what hard is, 221
    what soft is, 221
    why don’t water in ocean sink in, 219
    why does it run, 219
    why it puts fire out, 222
    why runs off a duck’s back, 233
    why sea water is salty, 351

  =Watson, Thomas A.=, (illus.), 70

  =Wave=, of light changed into heat, 36

  =Waves=, of sound, 79

  =Weight=, of light, 37
    of projectiles, 53

  =What= does the air weigh? 398
    animal can leap the greatest distance? 122
    causes an arrow to fly? 408
    makes some people bald? 143
    keeps a balloon up? 199
    makes a ball stop bouncing, 63
    are ball bearings? 180
    happens when a bee stings? 537
    makes the hills look blue sometimes? 255
    makes me blush? 194
    was the origin and meaning of bread? 460
    is the hottest spot on earth? 239
    holds a building up? 496
    makes a bubble explode, 108
    is carbonic acid? 509
    is a cable made of? 429
    is the eye of the camera? 22
    do ocean cables look like when cut in two? (illus.), 428
    do we mean by 18-carat fine? 266
    is clay? 495
    is color? 123
    produces the colors we see? 123
    makes the colors in the rainbow? 254
    makes the colors of the sunset? 253
    are cocoa shells? 390
    is cement? 95
    is cement used for? 95
    a cement mill looks like (illus.), 96
    is cement made of? 95
    is cement used for, 95
    is concrete? 95
    makes some things in the same room colder than others? 144
    does woolen cloth come from? 80
    was the cross-bow? 44
    are diamonds made of? 351
    causes dimples? 352
    makes us dream? 366
    were man’s first divisions of time? 314
    makes things whirl around when I am dizzy? 402
    is dust? 104
    becomes of the dust? 104
    are drone bees good for? 531
    is meant by deadening a floor or a wall? 79
    causes earache? 410
    makes an echo? 200
    are the principal parts of an elevator? 396
    causes the explosion in a gas engine? (illus.), 182
    happens when anything explodes? 205
    is an element? 349
    makes the hollow place in a boiled egg? 179
    is electricity? 329
    is an electric current? 334
    makes an electric magnet lift things? 326
    do we mean by Fahrenheit? 221
    makes a fish move in swimming? 233
    is fog? 105
    makes the water from a fountain shoot into the air? 198
    makes freckles come? 125
    makes a gasoline engine go? 181
    is gravitation? 267
    does specific gravity mean? 268
    makes a cold glass crack if we put hot water in it? 63
    are ghosts? 367
    causes the gurgle when I pour water from a bottle? 63
    causes hail? 124
    is the horizon? 244
    causes a hot box? 368
    good are the lines on the palms of our hands? 402
    does horse-power mean? 256
    is hydrogen gas? 349
    makes us feel hungry? 243
    makes knots in boards? 223
    were the earliest lamps? 295
    were the lamps of the wise and foolish maidens? 295
    happens when we laugh? 93
    makes us laugh when glad? 92
    is a leyden jar? 332
    is a lodestone? 327
    makes lobsters turn red? 245
    makes the lump come in my throat when I cry? 195
    makes a match light when we strike it? 198
    would we do without matches? 292
    is a metal? 265
    is the most valuable metal? 265
    is the milky way? 255
    is a molecule? 348
    is money? 455
    is motion? 61
    made the mountains? 401
    is music? 478
    does a note in music consist of? 490
    is organic matter? 174
    is oxygen? 349
    is nitrogen? 350
    makes nitroglycerin explode so readily? 206
    causes nightmare? 367
    is pain and why does it hurt? 244
    makes the different colors in paint? 229
    is pitch in music? 489
    is the principle of the wireless? 455
    makes some pencils hard and others soft? 467
    makes rays of light? 230
    makes us red in the face? 192
    makes the rings in the water when I throw
    a stone into it? 197
    is rubber? 386
    is wild rubber? 387
    should I do if stung by a bee? 537
    is the cause of shadows? 495
    makes the sea roar? 401
    does the bottom of the sea look like? 220
    becomes of the smoke? 106
    and why is smoke? 105
    causes the smoke when a gun goes off? 206
    is smokeless powder made of? 206
    makes snowflakes white? 409
    depth of snow is equivalent to an inch of rain? 241
    is soap made of? 411
    makes a soap bubble? 108
    shot tower looks like? 51
    makes us sneeze? 194
    is silver? 207
    happens when we stretch? 193
    makes me want to stretch? 192
    happens when I swallow? 195
    is sound? 485
    are the properties of sound? 486
    are the sounds we hear in a sea shell? 79
    makes the sounds like waves in a sea shell? 79
    does a sounding board do? 488
    is meant by the length of sound waves? 487
    makes us thirsty? 243
    makes me tired? 403
    a great steamship looks like inside (illus.), 346
    did the first telephone look like? (illus.), 72
    occurs when we think? 194
    are the big tanks near the gas works for? 298
    makes the stars twinkle? 38
    a ship’s turbine looks like (illus.), 344
    is the largest tree in the world? 242
    happens when we telephone? 65
    makes water boil? 220
    is the boiling-point of water? 220
    causes a whispering gallery? 201
    makes a wireless message go? 455
    makes the works of a watch go? 368
    makes the white caps on the waves white? 410
    is worry? 207
    causes the wind’s whistle? 139
    makes the kettle whistle? 198
    causes wrinkles? 196
    are X-rays? 307
    is yeast? 288

  =When= did man first try to fly? 126
    did man begin to live? 174
    were candles introduced? 296
    was illuminating gas discovered? 302
    was wheat first used in making bread? 461
    I throw a ball into the air, while walking why does it follow me?
    401
    was silk culture introduced in America? 111
    were street lamps first used? 295

  =Where= does bread come from? 460
    does water in the ocean go at low tide? 219
    does silk come from? 109
    are we when asleep? 365
    did the name calico come from? 123
    cement is obtained (illus.), 97
    does chalk come from? 18
    does chocolate come from? 388
    our coal comes from? 257
    does cotton come from? 470
    does the day begin? 324
    does the day change? 325
    did the term Dixie originate? 123
    does honey come from? 526
    is the horizon? 244
    does the hour change? 325
    the gas is taken from the coal (illus.), 299
    did all the names of people come from? 20
    did the expression “kick the bucket” originate? 321
    does leather come from? 538
    do living things come from? 174
    did life begin on earth? 174
    do we get ivory? 239
    do lead pencils come from? 466
    does the wooden part of a lead pencil come from? 469
    does a light go when it goes out? 36
    does linseed oil come from? 227
    does paint come from? 224
    does the rain go? 222
    are the best Persian rugs made? 167
    does rope come from? 353
    does salt come from? 493
    do we get soda? 494
    do all the little round stones come from? 494
    does the part of a stocking go that was where the hole comes? 64
    does sound come from? 78
    do school slates come from? 495
    do shoes come from? 541
    do sponges come from? 286
    do tears come from? 94
    do the tears go? 94
    did the name tobacco originate? 512
    is Havana tobacco grown? 513
    does tobacco come from? 512
    does tobacco grow? 512
    did all the water in the ocean come from? 218
    does our drinking water come from? 501
    does most of our wool come from? 81
    does the wind begin? 139
    is the wind when it is not blowing? 139
    does wool come from? 80
    did the term Yankee originate? 243

  =Wheat=, bread loaves of the world, 459
    grinding (illus.), 464
    harvesting (illus.), 460
    scouring of, 463
    tempering of, 463
    when first used in making bread, 461
    will it grow wild? 461

  =Wheel-lock= rifle (illus.), 46

  =Whispering gallery=, accidental, 201
    cause of, 201
    what it is, 201

  =Whistle=, what makes the kettle? 198

  =White Lead=, making (illus.), 225
    buckles, before corrosion (illus.), 225
    buckles after corrosion (illus.), 225
    buckles, making, 225

  =Who= started to make clothing from wool in America? 81
    discovered electricity? 333
    invented electric telegraph? 420
    made the first felt hat? 239
    made the first cent? 458
    made the first submarine boat? 280
    first discovered the silkworm? 109
    first discovered the power of gunpowder? 44
    invented flying? 126
    made the first piano? 478
    brought the first sheep to America? 80
    first wove silk thread into cloth? 109
    make the first shoes? 541
    made the first umbrella? 312

  =Why= don’t the air ever get used up? 140
    can’t we see air? 140
    do we grow aged? 196
    does an apple turn brown when cut? 106
    do coats have buttons on the sleeves? 64
    has a long coat buttons on the back? 64
    cannot babies walk as soon as born? 180
    are some people bald? 144
    don’t the birds stay South? 408
    does a ball bounce? 63
    does a balloon go up? 199
    do we call voting balloting? 122
    does a barber pole have stripes? 310
    do some things bend and others break? 62
    do the birds come back in the Spring? 407
    do birds sing? 408
    do birds go South in the Winter? 407
    are birds’ eggs of different colors? 233
    has a bee a sting? 336
    can you blow out a candle? 21, 36
    are bubbles round? 108
    does red make a bull angry? 490
    do we get a bump instead of a dent when we knock our heads? 201
    can’t we burn stones? 105
    has a long coat buttons? 64
    is bread so important? 460
    do I get out of breath when running? 191
    do we call a cab a hansom? 122
    does a hen cackle after laying an egg? 233
    do children like candy? 409
    is cement called Portland cement? 95
    do I get cold in a warm room? 125
    is it cold in winter? 141
    does cold make our hands blue? 192
    does an ear of corn have silk? 170
    do we count in tens? 10
    we cannot see in the dark, 91
    does the dark cause fear? 352
    do we have to die? 245
    does a dog turn round and round before he lies down, 229
    do we know we have dreamed when we wake up? 367
    does eating candy make some people fat? 409
    doesn’t an elevator fall? 397
    do our eyes sparkle when we are merry? 92
    do the eyes of some pictures follow us? 35
    is it difficult to walk straight with my eyes closed? 91
    do I get red in the face? 192
    are some faculties stronger than others? 403
    is a fire hot? 401
    does a fire go out? 37
    we fear the dark? 352
    cannot fishes live in air? 232
    do we have finger nails? 142
    are our fingers of different lengths? 142
    have we five fingers on each hand and five toes on each foot? 142
    do we have finger nails? 142
    does a gasoline engine go? 181
    do girls like dolls? 368
    is gold called precious? 266
    are gold and silver best for coining? 457
    is some gun-powder fine and others coarse grained? 206
    are some guns called gatling guns? 310
    does a glow-worm glow? 231
    do we stop growing? 195
    do we have hair? 143
    does the hair grow after the body stops growing? 144
    don’t my hair hurt when it is being cut? 143
    does my hair stand on end when I am frightened? 143
    is the right hand stronger than the left? 309
    does my heart beat faster when I am scared? 191
    does the heart beat when the brain is asleep? 191
    do our hearts beat faster when we are running? 191
    do they call it a honeymoon? 31
    is a horseshoe said to bring good luck? 311
    does it hurt when I cut my finger? 143
    we cry when hurt, 93
    does iron turn red when red hot? 107
    does iron sink in water? 106
    doesn’t an iron ship sink? 106
    do we have twelve men on a jury? 239
    does a lamp give a better light with the chimney on? 37
    are there many languages? 197
    do we laugh when glad? 92
    is lead so heavy? 267
    do they call them lead pencils? 466
    must life be reproduced? 174
    are some people light and others dark? 402
    did people of long ago live longer than we do now? 199
    do we use metal for coining? 456
    do they call it the milky way? 255
    do we need money? 455
    does the moon travel with us when we walk or ride? 399
    should we not sleep with the moon shining on us? 366
    do my muscles get sore when I play ball in the spring? 310
    does a nail get hot when hammered? 230
    do we have only seven octaves on a piano? 480
    does the ocean look blue at times? 219
    does oiling the axle make the wheel turn more easily? 400
    does an onion make the tears come? 38
    can’t I write on paper with a slate pencil? 18
    does a pencil write? 18
    are some races white and others black, yellow and brown? 537
    do they call it pin money? 231
    do we call them pistols? 46
    do plants produce seeds? 175
    does a poker get hot at both ends if left in the fire? 107
    does rain make the air fresh? 222
    are most people right-handed? 403
    don’t we make roads perfectly level? 104
    don’t we use pure rubber? 380
    does salt make us thirsty? 351
    don’t the scenery appear to move when I am in a street car? 399
    does the scenery appear to move when we are riding in a train? 399
    can cats and some other animals see in the dark? 91
    can we see farther when we are up high? 245
    do I turn white when scared? 193
    does silver tarnish? 266
    does the sheep precede the plow in civilizing a country? 81
    is the sky blue? 253
    do I sneeze? 194
    do we see stars when hit on eye? 268
    many stars are there? 223
    does a stick in water bend? 38
    does a sound stop when we touch a gong that has been sounded? 78
    can we make sounds with our throats? 78
    do people shake with the right hand? 231
    do we go to sleep? 365
    does it seem when we have slept all night that we have been asleep
    only a minute? 366
    can’t we sleep with our eye open? 92
    we can hear through speaking tubes, 487
    does a human being have to learn to swim? 125
    are cooking utensils made of tin? 267
    do we use copper telegraph wires? 266
    do my teeth chatter? 218
    are some things transparent and others are not? 350
    do I laugh when tickled? 93
    can we think of only one thing at a time? 193
    does thunder always come after the lightning? 140
    do we call them wisdom teeth? 125
    are some roads called turnpikes? 104
    is the sea water salt? 351
    will water run off a duck’s back? 233
    do we worry? 207
    don’t the water in the ocean sink in? 219
    is it warm in summer? 141
    does water run? 219
    do we say water is soft or hard? 221
    does a piece of wood float in water? 106
    do we wake up in the morning? 365
    do I yawn? 173
    does yeast make bread rise? 288

  =Will= people all be bald sometime? 144
    the sky ever fall down? 255

  =Windows=, how an explosion breaks them, 62

  =Wireless=, accidents, prevention of, 449
    aerial on R. R. stations (illus.), 451
    aerial on ship (illus.), 455
    antennæ, 447
    antennæ on trains (illus.), 450
    battery, 447
    coil, 447
    compass, 454
    development of, 454
    direction finder, 454
    distance of sending, 448
    equipment, 446
    first Marconi station, 452
    how it reaches ships at sea, 446
    icebergs (illus.), 449
    in the army (illus.), 447-448
    inventor of, 452
    key, 447
    masts, height of, 448
    G. Marconi, portrait, 452
    on trains (illus.), 450
    prevents accidents, 449
    principles of, 455
    receiving station in U. S. Army (illus.), 451
    spark gap, 447
    stations, shore (illus.), 446
    stations on trains (illus.), 450
    transmission automatic (illus.), 453
    transmission of messages (illus.), 453
    what kind of signs are used in? 446
    why don’t the message go to the wrong stations, 455
    world-wide use, 454

  =Wires=, copper telegraph, 266
    how put underground (illus.), 76
    wire-wound gun, 54

  =Wonders= performed by electric lift magnet (illus.), 326

  =Wool= beaming (illus.), 89
    bobbin in weaving machine, 86
    Burling (illus.), 88
    burr picker, 87
    carding, 85
    carding, finisher in cloth making (illus.), 89
    chloride of aluminum in making cloth, 87
    cleaning, 85
    made clothing from, 81
    combing (illus.), 86
    cost of in a suit of clothes, 83
    crop of the United States, 82
    dyeing, 85-87
    fabrics, 85
    fiber description, 83
    finishing, box (illus.), 87
    finish, perching (illus.), 90
    fulling cloth (illus.), 90
    gilling after carding (illus.), 86
    gilling and making top after combing (illus.), 86
    gilling (illus.), 87
    greasy matter in, 84
    how we get it off the sheep, 82
    how much does a sheep produce, 83
    how much does America produce, 82
    how made into cloth, 85
    how woolen cloth is made perfect, 88
    how shipped, 82
    loom, 86
    mending, perching (illus.), 88
    mending room (illus.), 88
    woolen mule spinning (illus.), 89
    napping, 89
    next to food as a vital necessity, 81
    piece dyeing (illus.), 90
    quality of a hundred years ago, 83
    raised to sell to manufacturers, 81
    reducer machine in wool making (illus.), 87
    ring twisting (illus.), 89
    shipped to manufacturers, 82
    shuttle in weaving, 86
    scouring (illus.), 85
    sorting (illus.), 84
    spinning process, 86
    spinning, 89
    English cap spinning, 89
    in one suit of clothes, 83
    sulphuric acid solution in making cloth, 87
    teasel, 89
    tramper, 82
    in United States, bulk of, 82
    warp thread, 86
    web, 86
    weaving (illus.), 88
    where does most of our wool come from? 81
    woof of, 86
    made into yarn, 86
    yarn inspecting (illus.), 89
    yolk of, 84

  =Woolen cloth=, ready for market (illus.), 90

  =Woolens and worsteds=, difference between, 84

  =Woolworth building= (illus.), 395

  =Words=, formation of, 19
    the first over a telephone, 74

  =World’s= bread loaves (illus.), 459

  =Worry=, definition of, 207
    what it is, 207
    Why we, 207

  =Worsted= carding (illus.), 85
    fabrics, 85

  =Worsteds and woolens=, difference of, 84

  =Wright Brothers=, first successful flights, 130

  =Wrinkles=, what causes, 196

  =Writing=, brush, the (illus.), 13
    earliest ways of, 12
    first done upon rocks, 11
    first imitation of, 12
    first metallic pen introduced, 15
    fluids for developing, 13
    how man learned to, 11
    how the monks did their, 14
    how a pen writes, 18
    modern way of, 16
    paper for, earliest, 14
    pen, invention of, 11
    pen, first steel (illus.), 15
    quill, the (illus.), 14
    Reed, the, in (illus.), 12
    steel tube pen in (illus.), 15
    steel pen, modern (illus.), 16
    Stylus, the (illus.), 11
    with chalk, 18
    why a pencil writes, 18

  =X-rays=, what are they? 307

  =Yankee=, where word originated, 243

  =Yarn=, made from wool, 86

  =Yawning=, why do, 173
    is it infectious, 192

  =Yeast=, what it is, 288
    why it makes bread rise, 288

  =Yes=, meaning of nod, 19

  =Zollner, Casper=, inventor of rifling, 46




  Transcriber’s Notes


  The language used in this ebook is that of the source document,
  including unusual or archaic spelling. The book was partly written
  by representatives of the industries concerned; inconsistencies in
  grammar, spelling, punctuation (including the use of decimal points
  and commas), style, lay-out, etc. have been retained. Contradictions
  and repetitions have not been addressed. Alphabetical sorting
  inconsistencies in the index have not been corrected.

  Page 218, ... and have them meet as shown in Fig. 13 ...: The
  illustrations in this chapter are not numbered. The illustration on
  page 215 shows the described meeting of the shields.

  Page 305, ... (as shown in Fig. 4): the illustrations with this
  article are not numbered.

  Page 307, The X-rays are discharged in straight lines as shown in the
  figure: there is no such figure in the book.

  Pages 328 and 330: page headings WHAT A LODESTONE IS and WHAT
  ELECTRICITY IS do not relate to the contents of the pages.

  Page 336, The pictures shown on the following pages ...: as printed;
  the illustrations are given on previous pages.

  Page 364, reference to figure 6: presumably the four illustrations on
  this page together form figure 6.

  Page 368, When you put oil on the axle, however, ...: some text may
  be missing.

  Page 376, ... or three-sixty-fourths of a second, and: as printed in
  the source document; some text is obviously missing.

  Page 489, ... of much importance. The two classes, only two of which
  are of much importance. The two classes ...: the redundant text is as
  printed in the source document.

  Page 491: There is no Fig. 4 in the source document; the unnumbered
  figure in the bottom right of the page is assumed to be Fig. 4.

  Page 502, captions with bottom illustration: at least one of the
  lengths given (4650 and 4560 feet) is likely to be a typographical
  error.

  Page 547, (The welt shoe has always been considered ...: the closing
  bracket is lacking.


  Changes made:

  Some minor obvious punctuation and typographical errors and
  unnecessarily repeated words have been corrected silently.

  Illustrations have been moved out of text paragraphs. Page
  headers have been transcribed as illustration captions (on top
  of illustrations) or as side notes at a suitable location on the
  page concerned, so that their reference in the index is (at least
  approximately) correct.

  Text that was not present as such in the source document but that
  was transcribed from within illustrations is given as part of the
  illustration caption.

  Page 29: ... never see the distance target or vessel ... changed to
  ... never see the distant target or vessel ....

  Page 46: Lock á là Miquelet changed to Lock à la Miquelet.

  Pages 74-75: closing double quotes inserted after ... went that very
  night.; ... had to look after it themselves.; ... speech had really
  been electrically reproduced. Opening double quotes inserted before
  Now, it so happened there, ...; My friend, Mr. William Hubbard, ....

  Page 114: ... the white mulberry or osage orange are fed the young
  worms ... changed to ... the white mulberry or osage orange are fed
  the young worm ....

  Page 124: ... called an ablate spheroid ... changed to ... called an
  oblate spheroid ....

  Page 126: Dr. Samuel Pierrpont Langley changed to Dr. Samuel Pierpont
  Langley.

  Page 167: ... against the loose row of cross threads to lighten it
  ... changed to ... against the loose row of cross threads to tighten
  it ....

  Page 205: ... than the heat will cause the air to expand suddenly ...
  changed to ... that the heat will cause the air to expand suddenly
  ...; ... a mixture of potassium, nitrate, or saltpeter, with powdered
  charcoal and phur ... changed to ... a mixture of potassium nitrate,
  or saltpeter, with powdered charcoal and sulphur ....

  Page 229: ... other machines called Mills,” ... changed to ... other
  machines called “Mills,” ....; ... which also adds in the drying and
  the working ... changed to ... which also aids in the drying and the
  working ....

  Page 265: ... there is another, solium, which is solid ... changed to
  ... there is another, sodium, which is solid ...; ... what is called
  a reverbratory furnace ... changed to what is called a reverberatory
  furnace ....

  Page 292: PROMOTHEAN MATCH changed to PROMETHEAN MATCH.

  Page 375: This toy we speak of was called a zoctrope changed to This
  toy we speak of was called a zoetrope.

  Page 376: ... projected at the rate of fourteen or sixteen to the
  minute ... changed to ... projected at the rate of fourteen or
  sixteen to the second ....

  Page 377: Footnote anchor [4] inserted.

  Page 414 ff.: Ellipses (...) have been added surrounding the
  continuing page headings and illustration captions.

  Pages 419 and 438, Morse codes: for the sake of clarity, the spacing
  between individual dashes and dots has been increased slightly.

  Page 490: ... if a red flag really makes a bull more exited ...
  changed to ... if a red flag really makes a bull more excited ....

  Page 493: The chemical name for salt is sodium which is derived ...
  changed to The chemical name for salt is sodium chloride which is
  derived ...; ... substances around us are composed of these elements
  along, or ... changed to ... substances around us are composed of
  these elements alone, or ....

  Page 550: ... for which the lingings were intended. After all the
  lingings have been prepared ... changed to ... for which the linings
  were intended. After all the linings have been prepared ....

  Index: several missing punctuation marks inserted for consistency.

  Page 583: Curtis biplane changed to Curtiss biplane.

  Page 585: Burline (illus.) changed to Burling (illus.)

  Page 586: Culverines, early type of changed to Culverins, early type
  of.

  Page 587: steal and flint changed to steel and flint.

  Page 588: Flying boot, interior arrangement changed to Flying boat,
  interior arrangement.

  Page 589: (How) the pictures in this both are made changed to (How)
  the pictures in this book are made.

  Page 590: (How) did shaking the head come to come no? changed to
  (How) did shaking the head come to mean no?; (How) does does the wool
  in a suit of clothes cost? changed to (How) much does the wool in a
  suit of clothes cost?; Hurt, why we cry changed to Hurt, why we cry
  when, 93.

  Page 591: the “Reverbere” changed to the “Réverbère”; (Lamp) from
  Nashagak hanging changed to (Lamp) from Nushagak hanging.

  Page 592: promothean changed to promethean.

  Page 593: Kurdestan (illus.) changed to Kurdistan (illus.).

  Page 595: Crakron or peaked changed to Crakrow or peaked.

  Page 597: omniscope changed to Omniscope; cucular diffusion battery
  in factory changed to circular diffusion battery in factory.

  Page 601: (Who) who make the first felt hat? changed to (Who) made
  the first felt hat?; (Why) don’t an elevator fall? changed to (Why)
  doesn’t an elevator fall?

  Page 603: (Writing) pen invention of, 00 changed to (Writing) pen,
  invention of, 11.





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THE INVENTIONS

RESEARCHES AND WRITINGS

OF

NIKOLA TESLA



TO HIS COUNTRYMEN

  IN EASTERN EUROPE THIS RECORD OF
  THE WORK ALREADY ACCOMPLISHED BY

  NIKOLA TESLA

  IS RESPECTFULLY DEDICATED



[Illustration: Nikola Tesla]



  THE INVENTIONS
  RESEARCHES AND WRITINGS

  OF

  NIKOLA TESLA


  WITH SPECIAL REFERENCE TO HIS WORK IN POLYPHASE
  CURRENTS AND HIGH POTENTIAL LIGHTING


  BY

  THOMAS COMMERFORD MARTIN

  Editor THE ELECTRICAL ENGINEER; Past-President American Institute
  Electrical Engineers


  1894
  THE ELECTRICAL ENGINEER
  NEW YORK

  D. VAN NOSTRAND COMPANY,
  NEW YORK.



  Entered according to Act of Congress in the year 1893 by
  T. C. MARTIN
  in the office of the Librarian of Congress at Washington


  Press of McIlroy & Emmet, 36 Cortlandt St., N. Y.




PREFACE.


The electrical problems of the present day lie largely in the economical
transmission of power and in the radical improvement of the means and
methods of illumination. To many workers and thinkers in the domain of
electrical invention, the apparatus and devices that are familiar,
appear cumbrous and wasteful, and subject to severe limitations. They
believe that the principles of current generation must be changed, the
area of current supply be enlarged, and the appliances used by the
consumer be at once cheapened and simplified. The brilliant successes of
the past justify them in every expectancy of still more generous
fruition.

The present volume is a simple record of the pioneer work done in such
departments up to date, by Mr. Nikola Tesla, in whom the world has
already recognized one of the foremost of modern electrical
investigators and inventors. No attempt whatever has been made here to
emphasize the importance of his researches and discoveries. Great ideas
and real inventions win their own way, determining their own place by
intrinsic merit. But with the conviction that Mr. Tesla is blazing a
path that electrical development must follow for many years to come, the
compiler has endeavored to bring together all that bears the impress of
Mr. Tesla's genius, and is worthy of preservation. Aside from its value
as showing the scope of his inventions, this volume may be of service as
indicating the range of his thought. There is intellectual profit in
studying the push and play of a vigorous and original mind.

Although the lively interest of the public in Mr. Tesla's work is
perhaps of recent growth, this volume covers the results of full ten
years. It includes his lectures, miscellaneous articles and
discussions, and makes note of all his inventions thus far known,
particularly those bearing on polyphase motors and the effects obtained
with currents of high potential and high frequency. It will be seen that
Mr. Tesla has ever pressed forward, barely pausing for an instant to
work out in detail the utilizations that have at once been obvious to
him of the new principles he has elucidated. Wherever possible his own
language has been employed.

It may be added that this volume is issued with Mr. Tesla's sanction and
approval, and that permission has been obtained for the re-publication
in it of such papers as have been read before various technical
societies of this country and Europe. Mr. Tesla has kindly favored the
author by looking over the proof sheets of the sections embodying his
latest researches. The work has also enjoyed the careful revision of the
author's friend and editorial associate, Mr. Joseph Wetzler, through
whose hands all the proofs have passed.

DECEMBER, 1893.

                                                              T. C. M.




CONTENTS.


PART I.

POLYPHASE CURRENTS.

  CHAPTER I.
  BIOGRAPHICAL AND INTRODUCTORY.                                       3

  CHAPTER II.
  A NEW SYSTEM OF ALTERNATING CURRENT MOTORS AND TRANSFORMERS.         7

  CHAPTER III.
  THE TESLA ROTATING MAGNETIC FIELD.--MOTORS WITH CLOSED
  CONDUCTORS.--SYNCHRONIZING MOTORS.--ROTATING FIELD TRANSFORMERS.     9

  CHAPTER IV.
  MODIFICATIONS AND EXPANSIONS OF THE TESLA POLYPHASE SYSTEMS.        26

  CHAPTER V.
  UTILIZING FAMILIAR TYPES OF GENERATORS OF THE CONTINUOUS CURRENT
  TYPE.                                                               31

  CHAPTER VI.
  METHOD OF OBTAINING DESIRED SPEED OF MOTOR OR GENERATOR.            36

  CHAPTER VII.
  REGULATOR FOR ROTARY CURRENT MOTORS.                                45

  CHAPTER VIII.
  SINGLE CIRCUIT, SELF-STARTING SYNCHRONIZING MOTORS.                 50

  CHAPTER IX.
  CHANGE FROM DOUBLE CURRENT TO SINGLE CURRENT MOTORS.                56

  CHAPTER X.
  MOTOR WITH "CURRENT LAG" ARTIFICIALLY SECURED.                      58

  CHAPTER XI.
  ANOTHER METHOD OF TRANSFORMATION FROM A TORQUE TO A SYNCHRONIZING
  MOTOR.                                                              62

  CHAPTER XII.
  "MAGNETIC LAG" MOTOR.                                               67

  CHAPTER XIII.
  METHOD OF OBTAINING DIFFERENCE OF PHASE BY MAGNETIC SHIELDING.      71

  CHAPTER XIV.
  TYPE OF TESLA SINGLE-PHASE MOTOR.                                   76

  CHAPTER XV.
  MOTORS WITH CIRCUITS OF DIFFERENT RESISTANCE.                       79

  CHAPTER XVI.
  MOTOR WITH EQUAL MAGNETIC ENERGIES IN FIELD AND ARMATURE.           81

  CHAPTER XVII.
  MOTORS WITH COINCIDING MAXIMA OF MAGNETIC EFFECT IN ARMATURE AND
  FIELD.                                                              83

  CHAPTER XVIII.
  MOTOR BASED ON THE DIFFERENCE OF PHASE IN THE MAGNETIZATION OF
  THE INNER AND OUTER PARTS OF AN IRON CORE.                          88

  CHAPTER XIX.
  ANOTHER TYPE OF TESLA INDUCTION MOTOR.                              92

  CHAPTER XX.
  COMBINATIONS OF SYNCHRONIZING MOTOR AND TORQUE MOTOR.               95

  CHAPTER XXI.
  MOTOR WITH A CONDENSER IN THE ARMATURE CIRCUIT.                    101

  CHAPTER XXII.
  MOTOR WITH CONDENSER IN ONE OF THE FIELD CIRCUITS.                 106

  CHAPTER XXIII.
  TESLA POLYPHASE TRANSFORMER.                                       109

  CHAPTER XXIV.
  A CONSTANT CURRENT TRANSFORMER WITH MAGNETIC SHIELD BETWEEN
  COILS OF PRIMARY AND SECONDARY.                                    113


PART II.

THE TESLA EFFECTS WITH HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS.

  CHAPTER XXV.
  INTRODUCTORY.--THE SCOPE OF THE TESLA LECTURES.                    119

  CHAPTER XXVI.
  THE NEW YORK LECTURE. EXPERIMENTS WITH ALTERNATE CURRENTS OF VERY
  HIGH FREQUENCY, AND THEIR APPLICATION TO METHODS OF ARTIFICIAL
  ILLUMINATION, MAY 20, 1891.                                        145

  CHAPTER XXVII.
  THE LONDON LECTURE. EXPERIMENTS WITH ALTERNATE CURRENTS OF HIGH
  POTENTIAL AND HIGH FREQUENCY, FEBRUARY 3, 1892.                    198

  CHAPTER XXVIII.
  THE PHILADELPHIA AND ST. LOUIS LECTURE. ON LIGHT AND OTHER HIGH
  FREQUENCY PHENOMENA, FEBRUARY AND MARCH, 1893.                     294

  CHAPTER XXIX.
  TESLA ALTERNATING CURRENT GENERATORS FOR HIGH FREQUENCY.           374

  CHAPTER XXX.
  ALTERNATE CURRENT ELECTROSTATIC INDUCTION APPARATUS.               392

  CHAPTER XXXI.
  "MASSAGE" WITH CURRENTS OF HIGH FREQUENCY.                         394

  CHAPTER XXXII.
  ELECTRIC DISCHARGE IN VACUUM TUBES.                                396


PART III.

MISCELLANEOUS INVENTIONS AND WRITINGS.

  CHAPTER XXXIII.
  METHOD OF OBTAINING DIRECT FROM ALTERNATING CURRENTS.              409

  CHAPTER XXXIV.
  CONDENSERS WITH PLATES IN OIL.                                     418

  CHAPTER XXXV.
  ELECTROLYTIC REGISTERING METER.                                    420

  CHAPTER XXXVI.
  THERMO-MAGNETIC MOTORS AND PYRO-MAGNETIC GENERATORS.               424

  CHAPTER XXXVII.
  ANTI-SPARKING DYNAMO BRUSH AND COMMUTATOR.                         432

  CHAPTER XXXVIII.
  AUXILIARY BRUSH REGULATION OF DIRECT CURRENT DYNAMOS.              438

  CHAPTER XXXIX.
  IMPROVEMENT IN DYNAMO AND MOTOR CONSTRUCTION.                      448

  CHAPTER XL.
  TESLA DIRECT CURRENT ARC LIGHTING SYSTEM.                          451

  CHAPTER XLI.
  IMPROVEMENT IN UNIPOLAR GENERATORS.                                465


PART IV.

APPENDIX: EARLY PHASE MOTORS AND THE TESLA OSCILLATORS.

  CHAPTER XLII.
  MR. TESLA'S PERSONAL EXHIBIT AT THE WORLD'S FAIR.                  477

  CHAPTER XLIII.
  THE TESLA MECHANICAL AND ELECTRICAL OSCILLATORS.                   486




PART I.

POLYPHASE CURRENTS.




CHAPTER I.

BIOGRAPHICAL AND INTRODUCTORY.


As an introduction to the record contained in this volume of Mr. Tesla's
investigations and discoveries, a few words of a biographical nature
will, it is deemed, not be out of place, nor other than welcome.

Nikola Tesla was born in 1857 at Smiljan, Lika, a borderland region of
Austro-Hungary, of the Serbian race, which has maintained against Turkey
and all comers so unceasing a struggle for freedom. His family is an old
and representative one among these Switzers of Eastern Europe, and his
father was an eloquent clergyman in the Greek Church. An uncle is to-day
Metropolitan in Bosnia. His mother was a woman of inherited ingenuity,
and delighted not only in skilful work of the ordinary household
character, but in the construction of such mechanical appliances as
looms and churns and other machinery required in a rural community.
Nikola was educated at Gospich in the public school for four years, and
then spent three years in the Real Schule. He was then sent to Carstatt,
Croatia, where he continued his studies for three years in the Higher
Real Schule. There for the first time he saw a steam locomotive. He
graduated in 1873, and, surviving an attack of cholera, devoted himself
to experimentation, especially in electricity and magnetism. His father
would have had him maintain the family tradition by entering the Church,
but native genius was too strong, and he was allowed to enter the
Polytechnic School at Gratz, to finish his studies, and with the object
of becoming a professor of mathematics and physics. One of the machines
there experimented with was a Gramme dynamo, used as a motor. Despite
his instructor's perfect demonstration of the fact that it was
impossible to operate a dynamo without commutator or brushes, Mr. Tesla
could not be convinced that such accessories were necessary or
desirable. He had already seen with quick intuition that a way could be
found to dispense with them; and from that time he may be said to have
begun work on the ideas that fructified ultimately in his rotating field
motors.

In the second year of his Gratz course, Mr. Tesla gave up the notion of
becoming a teacher, and took up the engineering curriculum. His studies
ended, he returned home in time to see his father die, and then went to
Prague and Buda-Pesth to study languages, with the object of qualifying
himself broadly for the practice of the engineering profession. For a
short time he served as an assistant in the Government Telegraph
Engineering Department, and then became associated with M. Puskas, a
personal and family friend, and other exploiters of the telephone in
Hungary. He made a number of telephonic inventions, but found his
opportunities of benefiting by them limited in various ways. To gain a
wider field of action, he pushed on to Paris and there secured
employment as an electrical engineer with one of the large companies in
the new industry of electric lighting.

It was during this period, and as early as 1882, that he began serious
and continued efforts to embody the rotating field principle in
operative apparatus. He was enthusiastic about it; believed it to mark a
new departure in the electrical arts, and could think of nothing else.
In fact, but for the solicitations of a few friends in commercial
circles who urged him to form a company to exploit the invention, Mr.
Tesla, then a youth of little worldly experience, would have sought an
immediate opportunity to publish his ideas, believing them to be worthy
of note as a novel and radical advance in electrical theory as well as
destined to have a profound influence on all dynamo electric machinery.

At last he determined that it would be best to try his fortunes in
America. In France he had met many Americans, and in contact with them
learned the desirability of turning every new idea in electricity to
practical use. He learned also of the ready encouragement given in the
United States to any inventor who could attain some new and valuable
result. The resolution was formed with characteristic quickness, and
abandoning all his prospects in Europe, he at once set his face
westward.

Arrived in the United States, Mr. Tesla took off his coat the day he
arrived, in the Edison Works. That place had been a goal of his
ambition, and one can readily imagine the benefit and stimulus derived
from association with Mr. Edison, for whom Mr. Tesla has always had the
strongest admiration. It was impossible, however, that, with his own
ideas to carry out, and his own inventions to develop, Mr. Tesla could
long remain in even the most delightful employ; and, his work now
attracting attention, he left the Edison ranks to join a company
intended to make and sell an arc lighting system based on some of his
inventions in that branch of the art. With unceasing diligence he
brought the system to perfection, and saw it placed on the market. But
the thing which most occupied his time and thoughts, however, all
through this period, was his old discovery of the rotating field
principle for alternating current work, and the application of it in
motors that have now become known the world over.

Strong as his convictions on the subject then were, it is a fact that
he stood very much alone, for the alternating current had no well
recognized place. Few electrical engineers had ever used it, and the
majority were entirely unfamiliar with its value, or even its essential
features. Even Mr. Tesla himself did not, until after protracted effort
and experimentation, learn how to construct alternating current
apparatus of fair efficiency. But that he had accomplished his purpose
was shown by the tests of Prof. Anthony, made in the of winter 1887-8,
when Tesla motors in the hands of that distinguished expert gave an
efficiency equal to that of direct current motors. Nothing now stood in
the way of the commercial development and introduction of such motors,
except that they had to be constructed with a view to operating on the
circuits then existing, which in this country were all of high
frequency.

The first full publication of his work in this direction--outside his
patents--was a paper read before the American Institute of Electrical
Engineers in New York, in May, 1888 (read at the suggestion of Prof.
Anthony and the present writer), when he exhibited motors that had been
in operation long previous, and with which his belief that brushes and
commutators could be dispensed with, was triumphantly proved to be
correct. The section of this volume devoted to Mr. Tesla's inventions in
the utilization of polyphase currents will show how thoroughly from the
outset he had mastered the fundamental idea and applied it in the
greatest variety of ways.

Having noted for years the many advantages obtainable with alternating
currents, Mr. Tesla was naturally led on to experiment with them at
higher potentials and higher frequencies than were common or approved
of. Ever pressing forward to determine in even the slightest degree the
outlines of the unknown, he was rewarded very quickly in this field
with results of the most surprising nature. A slight acquaintance with
some of these experiments led the compiler of this volume to urge Mr.
Tesla to repeat them before the American Institute of Electrical
Engineers. This was done in May, 1891, in a lecture that marked, beyond
question, a distinct departure in electrical theory and practice, and
all the results of which have not yet made themselves fully apparent.
The New York lecture, and its successors, two in number, are also
included in this volume, with a few supplementary notes.

Mr. Tesla's work ranges far beyond the vast departments of polyphase
currents and high potential lighting. The "Miscellaneous" section of
this volume includes a great many other inventions in arc lighting,
transformers, pyro-magnetic generators, thermo-magnetic motors,
third-brush regulation, improvements in dynamos, new forms of
incandescent lamps, electrical meters, condensers, unipolar dynamos, the
conversion of alternating into direct currents, etc. It is needless to
say that at this moment Mr. Tesla is engaged on a number of interesting
ideas and inventions, to be made public in due course. The present
volume deals simply with his work accomplished to date.




CHAPTER II.

A NEW SYSTEM OF ALTERNATING CURRENT MOTORS AND TRANSFORMERS.


The present section of this volume deals with polyphase currents, and
the inventions by Mr. Tesla, made known thus far, in which he has
embodied one feature or another of the broad principle of rotating field
poles or _resultant attraction_ exerted on the armature. It is needless
to remind electricians of the great interest aroused by the first
enunciation of the rotating field principle, or to dwell upon the
importance of the advance from a single alternating current, to methods
and apparatus which deal with more than one. Simply prefacing the
consideration here attempted of the subject, with the remark that in
nowise is the object of this volume of a polemic or controversial
nature, it may be pointed out that Mr. Tesla's work has not at all been
fully understood or realized up to date. To many readers, it is
believed, the analysis of what he has done in this department will be a
revelation, while it will at the same time illustrate the beautiful
flexibility and range of the principles involved. It will be seen that,
as just suggested, Mr. Tesla did not stop short at a mere rotating
field, but dealt broadly with the shifting of the resultant attraction
of the magnets. It will be seen that he went on to evolve the
"multiphase" system with many ramifications and turns; that he showed
the broad idea of motors employing currents of differing phase in the
armature with direct currents in the field; that he first described and
worked out the idea of an armature with a body of iron and coils closed
upon themselves; that he worked out both synchronizing and torque
motors; that he explained and illustrated how machines of ordinary
construction might be adapted to his system; that he employed condensers
in field and armature circuits, and went to the bottom of the
fundamental principles, testing, approving or rejecting, it would
appear, every detail that inventive ingenuity could hit upon.

Now that opinion is turning so emphatically in favor of lower
frequencies, it deserves special note that Mr. Tesla early recognized
the importance of the low frequency feature in motor work. In fact his
first motors exhibited publicly--and which, as Prof. Anthony showed in
his tests in the winter of 1887-8, were the equal of direct current
motors in efficiency, output and starting torque--were of the low
frequency type. The necessity arising, however, to utilize these motors
in connection with the existing high frequency circuits, our survey
reveals in an interesting manner Mr. Tesla's fertility of resource in
this direction. But that, after exhausting all the possibilities of this
field, Mr. Tesla returns to low frequencies, and insists on the
superiority of his polyphase system in alternating current distribution,
need not at all surprise us, in view of the strength of his convictions,
so often expressed, on this subject. This is, indeed, significant, and
may be regarded as indicative of the probable development next to be
witnessed.

Incidental reference has been made to the efficiency of rotating field
motors, a matter of much importance, though it is not the intention to
dwell upon it here. Prof. Anthony in his remarks before the American
Institute of Electrical Engineers, in May, 1888, on the two small Tesla
motors then shown, which he had tested, stated that one gave an
efficiency of about 50 per cent. and the other a little over sixty per
cent. In 1889, some tests were reported from Pittsburgh, made by Mr.
Tesla and Mr. Albert Schmid, on motors up to 10 H. P. and weighing about
850 pounds. These machines showed an efficiency of nearly 90 per cent.
With some larger motors it was then found practicable to obtain an
efficiency, with the three wire system, up to as high as 94 and 95 per
cent. These interesting figures, which, of course, might be supplemented
by others more elaborate and of later date, are cited to show that the
efficiency of the system has not had to wait until the present late day
for any demonstration of its commercial usefulness. An invention is none
the less beautiful because it may lack utility, but it must be a
pleasure to any inventor to know that the ideas he is advancing are
fraught with substantial benefits to the public.




CHAPTER III.

THE TESLA ROTATING MAGNETIC FIELD.--MOTORS WITH CLOSED
CONDUCTORS.--SYNCHRONIZING MOTORS.--ROTATING FIELD TRANSFORMERS.


The best description that can be given of what he attempted, and
succeeded in doing, with the rotating magnetic field, is to be found in
Mr. Tesla's brief paper explanatory of his rotary current, polyphase
system, read before the American Institute of Electrical Engineers, in
New York, in May, 1888, under the title "A New System of Alternate
Current Motors and Transformers." As a matter of fact, which a perusal
of the paper will establish, Mr. Tesla made no attempt in that paper to
describe all his work. It dealt in reality with the few topics
enumerated in the caption of this chapter. Mr. Tesla's reticence was no
doubt due largely to the fact that his action was governed by the wishes
of others with whom he was associated, but it may be worth mention that
the compiler of this volume--who had seen the motors running, and who
was then chairman of the Institute Committee on Papers and Meetings--had
great difficulty in inducing Mr. Tesla to give the Institute any paper
at all. Mr. Tesla was overworked and ill, and manifested the greatest
reluctance to an exhibition of his motors, but his objections were at
last overcome. The paper was written the night previous to the meeting,
in pencil, very hastily, and under the pressure just mentioned.

In this paper casual reference was made to two special forms of motors
not within the group to be considered. These two forms were: 1. A motor
with one of its circuits in series with a transformer, and the other in
the secondary of the transformer. 2. A motor having its armature circuit
connected to the generator, and the field coils closed upon themselves.
The paper in its essence is as follows, dealing with a few leading
features of the Tesla system, namely, the rotating magnetic field,
motors with closed conductors, synchronizing motors, and rotating field
transformers:--

The subject which I now have the pleasure of bringing to your notice is
a novel system of electric distribution and transmission of power by
means of alternate currents, affording peculiar advantages, particularly
in the way of motors, which I am confident will at once establish the
superior adaptability of these currents to the transmission of power and
will show that many results heretofore unattainable can be reached by
their use; results which are very much desired in the practical
operation of such systems, and which cannot be accomplished by means of
continuous currents.

Before going into a detailed description of this system, I think it
necessary to make a few remarks with reference to certain conditions
existing in continuous current generators and motors, which, although
generally known, are frequently disregarded.

In our dynamo machines, it is well known, we generate alternate currents
which we direct by means of a commutator, a complicated device and, it
may be justly said, the source of most of the troubles experienced in
the operation of the machines. Now, the currents so directed cannot be
utilized in the motor, but they must--again by means of a similar
unreliable device--be reconverted into their original state of alternate
currents. The function of the commutator is entirely external, and in no
way does it affect the internal working of the machines. In reality,
therefore, all machines are alternate current machines, the currents
appearing as continuous only in the external circuit during their
transit from generator to motor. In view simply of this fact, alternate
currents would commend themselves as a more direct application of
electrical energy, and the employment of continuous currents would only
be justified if we had dynamos which would primarily generate, and
motors which would be directly actuated by, such currents.

But the operation of the commutator on a motor is twofold; first, it
reverses the currents through the motor, and secondly, it effects
automatically, a progressive shifting of the poles of one of its
magnetic constituents. Assuming, therefore, that both of the useless
operations in the systems, that is to say, the directing of the
alternate currents on the generator and reversing the direct currents on
the motor, be eliminated, it would still be necessary, in order to cause
a rotation of the motor, to produce a progressive shifting of the poles
of one of its elements, and the question presented itself--How to
perform this operation by the direct action of alternate currents? I
will now proceed to show how this result was accomplished.

[Illustration: FIG. 1.]

[Illustration: FIG. 1a.]

[Illustration: FIG. 2.]

[Illustration: FIG. 2a.]

In the first experiment a drum-armature was provided with two coils at
right angles to each other, and the ends of these coils were connected
to two pairs of insulated contact-rings as usual. A ring was then made
of thin insulated plates of sheet-iron and wound with four coils, each
two opposite coils being connected together so as to produce free poles
on diametrically opposite sides of the ring. The remaining free ends of
the coils were then connected to the contact-rings of the generator
armature so as to form two independent circuits, as indicated in Fig. 9.
It may now be seen what results were secured in this combination, and
with this view I would refer to the diagrams, Figs. 1 to 8_a_. The field
of the generator being independently excited, the rotation of the
armature sets up currents in the coils C C_{1}, varying in strength and
direction in the well-known manner. In the position shown in Fig. 1, the
current in coil C is nil, while coil C_{1} is traversed by its maximum
current, and the connections may be such that the ring is magnetized by
the coils c_{1} c_{1}, as indicated by the letters N S in Fig. 1_a_,
the magnetizing effect of the coils c c being nil, since these coils
are included in the circuit of coil C.

[Illustration: FIG. 3.]

[Illustration: FIG. 3a.]

In Fig. 2, the armature coils are shown in a more advanced position,
one-eighth of one revolution being completed. Fig. 2_a_ illustrates the
corresponding magnetic condition of the ring. At this moment the coil
C_{1} generates a current of the same direction as previously, but
weaker, producing the poles n_{1} s_{1} upon the ring; the coil C also
generates a current of the same direction, and the connections may be
such that the coils c c produce the poles n s, as shown in Fig. 2_a_.
The resulting polarity is indicated by the letters N S, and it will be
observed that the poles of the ring have been shifted one-eighth of the
periphery of the same.

[Illustration: FIG. 4.]

[Illustration: FIG. 4a.]

In Fig. 3 the armature has completed one quarter of one revolution. In
this phase the current in coil C is a maximum, and of such direction as
to produce the poles N S in Fig. 3_a_, whereas the current in coil C_{1}
is nil, this coil being at its neutral position. The poles N S in Fig.
3_a_ are thus shifted one quarter of the circumference of the ring.

Fig. 4 shows the coils C C in a still more advanced position, the
armature having completed three-eighths of one revolution. At that
moment the coil C still generates a current of the same direction as
before, but of less strength, producing the comparatively weaker poles
n s in Fig. 4_a_. The current in the coil C_{1} is of the same strength,
but opposite direction. Its effect is, therefore, to produce upon the
ring the poles n_{1} s_{1}, as indicated, and a polarity, N S, results,
the poles now being shifted three-eighths of the periphery of the ring.

[Illustration: FIG. 5.]

[Illustration: FIG. 5a.]

In Fig. 5 one half of one revolution of the armature is completed, and
the resulting magnetic condition of the ring is indicated in Fig. 5_a_.
Now the current in coil C is nil, while the coil C_{1} yields its
maximum current, which is of the same direction as previously; the
magnetizing effect is, therefore, due to the coils, c_{1} c_{1} alone,
and, referring to Fig. 5_a_, it will be observed that the poles N S are
shifted one half of the circumference of the ring. During the next half
revolution the operations are repeated, as represented in the Figs. 6 to
8_a_.

[Illustration: FIG. 6.]

[Illustration: FIG. 6a.]

A reference to the diagrams will make it clear that during one
revolution of the armature the poles of the ring are shifted once around
its periphery, and, each revolution producing like effects, a rapid
whirling of the poles in harmony with the rotation of the armature is
the result. If the connections of either one of the circuits in the ring
are reversed, the shifting of the poles is made to progress in the
opposite direction, but the operation is identically the same. Instead
of using four wires, with like result, three wires may be used, one
forming a common return for both circuits.

[Illustration: FIG. 7.]

[Illustration: FIG. 7_a_.]

This rotation or whirling of the poles manifests itself in a series of
curious phenomena. If a delicately pivoted disc of steel or other
magnetic metal is approached to the ring it is set in rapid rotation,
the direction of rotation varying with the position of the disc. For
instance, noting the direction outside of the ring it will be found that
inside the ring it turns in an opposite direction, while it is
unaffected if placed in a position symmetrical to the ring. This is
easily explained. Each time that a pole approaches, it induces an
opposite pole in the nearest point on the disc, and an attraction is
produced upon that point; owing to this, as the pole is shifted further
away from the disc a tangential pull is exerted upon the same, and the
action being constantly repeated, a more or less rapid rotation of the
disc is the result. As the pull is exerted mainly upon that part which
is nearest to the ring, the rotation outside and inside, or right and
left, respectively, is in opposite directions, Fig. 9. When placed
symmetrically to the ring, the pull on the opposite sides of the disc
being equal, no rotation results. The action is based on the magnetic
inertia of iron; for this reason a disc of hard steel is much more
affected than a disc of soft iron, the latter being capable of very
rapid variations of magnetism. Such a disc has proved to be a very
useful instrument in all these investigations, as it has enabled me to
detect any irregularity in the action. A curious effect is also produced
upon iron filings. By placing some upon a paper and holding them
externally quite close to the ring, they are set in a vibrating motion,
remaining in the same place, although the paper may be moved back and
forth; but in lifting the paper to a certain height which seems to be
dependent on the intensity of the poles and the speed of rotation, they
are thrown away in a direction always opposite to the supposed movement
of the poles. If a paper with filings is put flat upon the ring and the
current turned on suddenly, the existence of a magnetic whirl may easily
be observed.

To demonstrate the complete analogy between the ring and a revolving
magnet, a strongly energized electro-magnet was rotated by mechanical
power, and phenomena identical in every particular to those mentioned
above were observed.

Obviously, the rotation of the poles produces corresponding inductive
effects and may be utilized to generate currents in a closed conductor
placed within the influence of the poles. For this purpose it is
convenient to wind a ring with two sets of superimposed coils forming
respectively the primary and secondary circuits, as shown in Fig. 10. In
order to secure the most economical results the magnetic circuit should
be completely closed, and with this object in view the construction may
be modified at will.

[Illustration: FIG. 8.]

[Illustration: FIG. 8_a_.]

The inductive effect exerted upon the secondary coils will be mainly due
to the shifting or movement of the magnetic action; but there may also
be currents set up in the circuits in consequence of the variations in
the intensity of the poles. However, by properly designing the generator
and determining the magnetizing effect of the primary coils, the latter
element may be made to disappear. The intensity of the poles being
maintained constant, the action of the apparatus will be perfect, and
the same result will be secured as though the shifting were effected by
means of a commutator with an infinite number of bars. In such case the
theoretical relation between the energizing effect of each set of
primary coils and their resultant magnetizing effect may be expressed by
the equation of a circle having its centre coinciding with that of an
orthogonal system of axes, and in which the radius represents the
resultant and the co-ordinates both of its components. These are then
respectively the sine and cosine of the angle _a_ between the radius and
one of the axes (_OX_). Referring to Fig. 11, we have r^2 = x^2 + y^2;
where x = r cos _a_, and y = r sin _a_.

Assuming the magnetizing effect of each set of coils in the transformer
to be proportional to the current--which may be admitted for weak
degrees of magnetization--then x = Kc and y = Kc^1, where K is a
constant and c and c^1 the current in both sets of coils respectively.
Supposing, further, the field of the generator to be uniform, we have
for constant speed

  c^1 = K^1 sin _a_ and
  c = K^1 sin (90 deg. + _a_) = K^1 cos _a_,

where K^1 is a constant. See Fig. 12.

Therefore,

  x = Kc = K K^1 cos _a_;
  y = Kc^1 = K K^1 sin _a_; and
  K K^1 = r.

[Illustration: FIG. 9.]

That is, for a uniform field the disposition of the two coils at right
angles will secure the theoretical result, and the intensity of the
shifting poles will be constant. But from r^2 = x^2 + y^2 it follows
that for y = 0, r = x; it follows that the joint magnetizing effect
of both sets of coils should be equal to the effect of one set when at
its maximum action. In transformers and in a certain class of motors the
fluctuation of the poles is not of great importance, but in another
class of these motors it is desirable to obtain the theoretical result.

In applying this principle to the construction of motors, two typical
forms of motor have been developed. First, a form having a comparatively
small rotary effort at the start but maintaining a perfectly uniform
speed at all loads, which motor has been termed synchronous. Second, a
form possessing a great rotary effort at the start, the speed being
dependent on the load.

These motors may be operated in three different ways: 1. By the
alternate currents of the source only. 2. By a combined action of these
and of induced currents. 3. By the joint action of alternate and
continuous currents.

[Illustration: FIG. 10.]

The simplest form of a synchronous motor is obtained by winding a
laminated ring provided with pole projections with four coils, and
connecting the same in the manner before indicated. An iron disc having
a segment cut away on each side may be used as an armature. Such a motor
is shown in Fig. 9. The disc being arranged to rotate freely within the
ring in close proximity to the projections, it is evident that as the
poles are shifted it will, owing to its tendency to place itself in such
a position as to embrace the greatest number of the lines of force,
closely follow the movement of the poles, and its motion will be
synchronous with that of the armature of the generator; that is, in the
peculiar disposition shown in Fig. 9, in which the armature produces by
one revolution two current impulses in each of the circuits. It is
evident that if, by one revolution of the armature, a greater number of
impulses is produced, the speed of the motor will be correspondingly
increased. Considering that the attraction exerted upon the disc is
greatest when the same is in close proximity to the poles, it follows
that such a motor will maintain exactly the same speed at all loads
within the limits of its capacity.

To facilitate the starting, the disc may be provided with a coil closed
upon itself. The advantage secured by such a coil is evident. On the
start the currents set up in the coil strongly energize the disc and
increase the attraction exerted upon the same by the ring, and currents
being generated in the coil as long as the speed of the armature is
inferior to that of the poles, considerable work may be performed by
such a motor even if the speed be below normal. The intensity of the
poles being constant, no currents will be generated in the coil when the
motor is turning at its normal speed.

Instead of closing the coil upon itself, its ends may be connected to
two insulated sliding rings, and a continuous current supplied to these
from a suitable generator. The proper way to start such a motor is to
close the coil upon itself until the normal speed is reached, or nearly
so, and then turn on the continuous current. If the disc be very
strongly energized by a continuous current the motor may not be able to
start, but if it be weakly energized, or generally so that the
magnetizing effect of the ring is preponderating, it will start and
reach the normal speed. Such a motor will maintain absolutely the same
speed at all loads. It has also been found that if the motive power of
the generator is not excessive, by checking the motor the speed of the
generator is diminished in synchronism with that of the motor. It is
characteristic of this form of motor that it cannot be reversed by
reversing the continuous current through the coil.

[Illustration: FIG. 11.]

[Illustration: FIG. 12.]

The synchronism of these motors may be demonstrated experimentally in a
variety of ways. For this purpose it is best to employ a motor
consisting of a stationary field magnet and an armature arranged to
rotate within the same, as indicated in Fig. 13. In this case the
shifting of the poles of the armature produces a rotation of the latter
in the opposite direction. It results therefrom that when the normal
speed is reached, the poles of the armature assume fixed positions
relatively to the field magnet, and the same is magnetized by
induction, exhibiting a distinct pole on each of the pole-pieces. If a
piece of soft iron is approached to the field magnet, it will at the
start be attracted with a rapid vibrating motion produced by the
reversals of polarity of the magnet, but as the speed of the armature
increases, the vibrations become less and less frequent and finally
entirely cease. Then the iron is weakly but permanently attracted,
showing that synchronism is reached and the field magnet energized by
induction.

The disc may also be used for the experiment. If held quite close to the
armature it will turn as long as the speed of rotation of the poles
exceeds that of the armature; but when the normal speed is reached, or
very nearly so, it ceases to rotate and is permanently attracted.

[Illustration: FIG. 13.]

A crude but illustrative experiment is made with an incandescent lamp.
Placing the lamp in circuit with the continuous current generator and in
series with the magnet coil, rapid fluctuations are observed in the
light in consequence of the induced currents set up in the coil at the
start; the speed increasing, the fluctuations occur at longer intervals,
until they entirely disappear, showing that the motor has attained its
normal speed. A telephone receiver affords a most sensitive instrument;
when connected to any circuit in the motor the synchronism may be easily
detected on the disappearance of the induced currents.

In motors of the synchronous type it is desirable to maintain the
quantity of the shifting magnetism constant, especially if the magnets
are not properly subdivided.

To obtain a rotary effort in these motors was the subject of long
thought. In order to secure this result it was necessary to make such a
disposition that while the poles of one element of the motor are shifted
by the alternate currents of the source, the poles produced upon the
other elements should always be maintained in the proper relation to the
former, irrespective of the speed of the motor. Such a condition exists
in a continuous current motor; but in a synchronous motor, such as
described, this condition is fulfilled only when the speed is normal.

[Illustration: FIG. 14.]

The object has been attained by placing within the ring a properly
subdivided cylindrical iron core wound with several independent coils
closed upon themselves. Two coils at right angles as in Fig. 14, are
sufficient, but a greater number may be advantageously employed. It
results from this disposition that when the poles of the ring are
shifted, currents are generated in the closed armature coils. These
currents are the most intense at or near the points of the greatest
density of the lines of force, and their effect is to produce poles upon
the armature at right angles to those of the ring, at least
theoretically so; and since this action is entirely independent of the
speed--that is, as far as the location of the poles is concerned--a
continuous pull is exerted upon the periphery of the armature. In many
respects these motors are similar to the continuous current motors. If
load is put on, the speed, and also the resistance of the motor, is
diminished and more current is made to pass through the energizing
coils, thus increasing the effort. Upon the load being taken off, the
counter-electromotive force increases and less current passes through
the primary or energizing coils. Without any load the speed is very
nearly equal to that of the shifting poles of the field magnet.

[Illustration: FIG. 15.]

[Illustration: FIG. 16.]

[Illustration: FIG. 17.]

It will be found that the rotary effort in these motors fully equals
that of the continuous current motors. The effort seems to be greatest
when both armature and field magnet are without any projections; but as
in such dispositions the field cannot be concentrated, probably the best
results will be obtained by leaving pole projections on one of the
elements only. Generally, it may be stated the projections diminish the
torque and produce a tendency to synchronism.

A characteristic feature of motors of this kind is their property of
being very rapidly reversed. This follows from the peculiar action of
the motor. Suppose the armature to be rotating and the direction of
rotation of the poles to be reversed. The apparatus then represents a
dynamo machine, the power to drive this machine being the momentum
stored up in the armature and its speed being the sum of the speeds of
the armature and the poles.

[Illustration: FIG. 18.]

[Illustration: FIG. 19.]

[Illustration: FIG. 20.]

[Illustration: FIG. 21.]

If we now consider that the power to drive such a dynamo would be very
nearly proportional to the third power of the speed, for that reason
alone the armature should be quickly reversed. But simultaneously with
the reversal another element is brought into action, namely, as the
movement of the poles with respect to the armature is reversed, the
motor acts like a transformer in which the resistance of the secondary
circuit would be abnormally diminished by producing in this circuit an
additional electromotive force. Owing to these causes the reversal is
instantaneous.

If it is desirable to secure a constant speed, and at the same time a
certain effort at the start, this result may be easily attained in a
variety of ways. For instance, two armatures, one for torque and the
other for synchronism, may be fastened on the same shaft and any desired
preponderance may be given to either one, or an armature may be wound
for rotary effort, but a more or less pronounced tendency to synchronism
may be given to it by properly constructing the iron core; and in many
other ways.

As a means of obtaining the required phase of the currents in both the
circuits, the disposition of the two coils at right angles is the
simplest, securing the most uniform action; but the phase may be
obtained in many other ways, varying with the machine employed. Any of
the dynamos at present in use may be easily adapted for this purpose by
making connections to proper points of the generating coils. In closed
circuit armatures, such as used in the continuous current systems, it is
best to make four derivations from equi-distant points or bars of the
commutator, and to connect the same to four insulated sliding rings on
the shaft. In this case each of the motor circuits is connected to two
diametrically opposite bars of the commutator. In such a disposition the
motor may also be operated at half the potential and on the three-wire
plan, by connecting the motor circuits in the proper order to three of
the contact rings.

In multipolar dynamo machines, such as used in the converter systems,
the phase is conveniently obtained by winding upon the armature two
series of coils in such a manner that while the coils of one set or
series are at their maximum production of current, the coils of the
other will be at their neutral position, or nearly so, whereby both sets
of coils may be subjected simultaneously or successively to the inducing
action of the field magnets.

Generally the circuits in the motor will be similarly disposed, and
various arrangements may be made to fulfill the requirements; but the
simplest and most practicable is to arrange primary circuits on
stationary parts of the motor, thereby obviating, at least in certain
forms, the employment of sliding contacts. In such a case the magnet
coils are connected alternately in both the circuits; that is, 1, 3,
5 ... in one, and 2, 4, 6 ... in the other, and the coils of each set
of series may be connected all in the same manner, or alternately in
opposition; in the latter case a motor with half the number of poles
will result, and its action will be correspondingly modified. The Figs.
15, 16, and 17, show three different phases, the magnet coils in each
circuit being connected alternately in opposition. In this case there
will be always four poles, as in Figs. 15 and 17; four pole projections
will be neutral; and in Fig. 16 two adjacent pole projections will have
the same polarity. If the coils are connected in the same manner there
will be eight alternating poles, as indicated by the letters n' s'
in Fig. 15.

The employment of multipolar motors secures in this system an advantage
much desired and unattainable in the continuous current system, and that
is, that a motor may be made to run exactly at a predetermined speed
irrespective of imperfections in construction, of the load, and, within
certain limits, of electromotive force and current strength.

In a general distribution system of this kind the following plan should
be adopted. At the central station of supply a generator should be
provided having a considerable number of poles. The motors operated from
this generator should be of the synchronous type, but possessing
sufficient rotary effort to insure their starting. With the observance
of proper rules of construction it may be admitted that the speed of
each motor will be in some inverse proportion to its size, and the
number of poles should be chosen accordingly. Still, exceptional demands
may modify this rule. In view of this, it will be advantageous to
provide each motor with a greater number of pole projections or coils,
the number being preferably a multiple of two and three. By this means,
by simply changing the connections of the coils, the motor may be
adapted to any probable demands.

If the number of the poles in the motor is even, the action will be
harmonious and the proper result will be obtained; if this is not the
case, the best plan to be followed is to make a motor with a double
number of poles and connect the same in the manner before indicated, so
that half the number of poles result. Suppose, for instance, that the
generator has twelve poles, and it would be desired to obtain a speed
equal to 12/7 of the speed of the generator. This would require a motor
with seven pole projections or magnets, and such a motor could not be
properly connected in the circuits unless fourteen armature coils would
be provided, which would necessitate the employment of sliding
contacts. To avoid this, the motor should be provided with fourteen
magnets and seven connected in each circuit, the magnets in each circuit
alternating among themselves. The armature should have fourteen closed
coils. The action of the motor will not be quite as perfect as in the
case of an even number of poles, but the drawback will not be of a
serious nature.

However, the disadvantages resulting from this unsymmetrical form will
be reduced in the same proportion as the number of the poles is
augmented.

If the generator has, say, n, and the motor n_{1} poles, the speed of
the motor will be equal to that of the generator multiplied by n/n_{1}.

The speed of the motor will generally be dependent on the number of the
poles, but there may be exceptions to this rule. The speed may be
modified by the phase of the currents in the circuit or by the character
of the current impulses or by intervals between each or between groups
of impulses. Some of the possible cases are indicated in the diagrams,
Figs. 18, 19, 20 and 21, which are self-explanatory. Fig. 18 represents
the condition generally existing, and which secures the best result. In
such a case, if the typical form of motor illustrated in Fig. 9 is
employed, one complete wave in each circuit will produce one revolution
of the motor. In Fig. 19 the same result will be effected by one wave in
each circuit, the impulses being successive; in Fig. 20 by four, and in
Fig. 21 by eight waves.

By such means any desired speed may be attained, that is, at least
within the limits of practical demands. This system possesses this
advantage, besides others, resulting from simplicity. At full loads the
motors show an efficiency fully equal to that of the continuous current
motors. The transformers present an additional advantage in their
capability of operating motors. They are capable of similar
modifications in construction, and will facilitate the introduction of
motors and their adaptation to practical demands. Their efficiency
should be higher than that of the present transformers, and I base my
assertion on the following:

In a transformer, as constructed at present, we produce the currents in
the secondary circuit by varying the strength of the primary or exciting
currents. If we admit proportionality with respect to the iron core the
inductive effect exerted upon the secondary coil will be proportional
to the numerical sum of the variations in the strength of the exciting
current per unit of time; whence it follows that for a given variation
any prolongation of the primary current will result in a proportional
loss. In order to obtain rapid variations in the strength of the
current, essential to efficient induction, a great number of undulations
are employed; from this practice various disadvantages result. These
are: Increased cost and diminished efficiency of the generator; more
waste of energy in heating the cores, and also diminished output of the
transformer, since the core is not properly utilized, the reversals
being too rapid. The inductive effect is also very small in certain
phases, as will be apparent from a graphic representation, and there may
be periods of inaction, if there are intervals between the succeeding
current impulses or waves. In producing a shifting of the poles in a
transformer, and thereby inducing currents, the induction is of the
ideal character, being always maintained at its maximum action. It is
also reasonable to assume that by a shifting of the poles less energy
will be wasted than by reversals.




CHAPTER IV.

MODIFICATIONS AND EXPANSIONS OF THE TESLA POLYPHASE SYSTEMS.


In his earlier papers and patents relative to polyphase currents, Mr.
Tesla devoted himself chiefly to an enunciation of the broad lines and
ideas lying at the basis of this new work; but he supplemented this
immediately by a series of other striking inventions which may be
regarded as modifications and expansions of certain features of the
Tesla systems. These we shall now proceed to deal with.

In the preceding chapters we have thus shown and described the Tesla
electrical systems for the transmission of power and the conversion and
distribution of electrical energy, in which the motors and the
transformers contain two or more coils or sets of coils, which were
connected up in independent circuits with corresponding coils of an
alternating current generator, the operation of the system being brought
about by the co-operation of the alternating currents in the independent
circuits in progressively moving or shifting the poles or points of
maximum magnetic effect of the motors or converters. In these systems
two independent conductors are employed for each of the independent
circuits connecting the generator with the devices for converting the
transmitted currents into mechanical energy or into electric currents of
another character. This, however, is not always necessary. The two or
more circuits may have a single return path or wire in common, with a
loss, if any, which is so extremely slight that it may be disregarded
entirely. For the sake of illustration, if the generator have two
independent coils and the motor two coils or two sets of coils in
corresponding relations to its operative elements one terminal of each
generator coil is connected to the corresponding terminals of the motor
coils through two independent conductors, while the opposite terminals
of the respective coils are both connected to one return wire. The
following description deals with the modification. Fig. 22 is a
diagrammatic illustration of a generator and single motor constructed
and electrically connected in accordance with the invention. Fig. 23 is
a diagram of the system as it is used in operating motors or converters,
or both, in parallel, while Fig. 24 illustrates diagrammatically the
manner of operating two or more motors or converters, or both, in
series. Referring to Fig. 22, A A designate the poles of the field
magnets of an alternating-current generator, the armature of which,
being in this case cylindrical in form and mounted on a shaft, C, is
wound longitudinally with coils B B'. The shaft C carries three
insulated contact-rings, _a b c_, to two of which, as _b c_, one
terminal of each coil, as _e d_, is connected. The remaining terminals,
_f g_, are both connected to the third ring, _a_.

[Illustration: FIG. 22.]

[Illustration: FIG. 24.]

A motor in this case is shown as composed of a ring, H, wound with four
coils, I I J J, electrically connected, so as to co-operate in pairs,
with a tendency to fix the poles of the ring at four points ninety
degrees apart. Within the magnetic ring H is a disc or cylindrical core
wound with two coils, G G', which may be connected to form two closed
circuits. The terminals _j k_ of the two sets or pairs of coils are
connected, respectively, to the binding-posts E' F', and the other
terminals, _h i_, are connected to a single binding-post, D'. To operate
the motor, three line-wires are used to connect the terminals of the
generator with those of the motor.

[Illustration: FIG. 23.]

So far as the apparent action or mode of operation of this arrangement
is concerned, the single wire D, which is, so to speak, a common
return-wire for both circuits, may be regarded as two independent wires.
In the illustration, with the order of connection shown, coil B' of the
generator is producing its maximum current and coil B its minimum; hence
the current which passes through wire e, ring b, brush b', line-wire E,
terminal E', wire j, coils I I, wire or terminal D', line-wire D, brush
_a'_, ring _a_, and wire _f_, fixes the polar line of the motor midway
between the two coils I I; but as the coil B' moves from the position
indicated it generates less current, while coil B, moving into the
field, generates more. The current from coil B passes through the
devices and wires designated by the letters _d_, _c_, C' F, F' _k_, J J,
_i_, D', D, _a'_, _a_, and _g_, and the position of the poles of the
motor will be due to the resultant effect of the currents in the two
sets of coils--that is, it will be advanced in proportion to the advance
or forward movement of the armature coils. The movement of the
generator-armature through one-quarter of a revolution will obviously
bring coil B' into its neutral position and coil B into its position of
maximum effect, and this shifts the poles ninety degrees, as they are
fixed solely by coils B. This action is repeated for each quarter of a
complete revolution.

When more than one motor or other device is employed, they may be run
either in parallel or series. In Fig. 23 the former arrangement is
shown. The electrical device is shown as a converter, L, of which the
two sets of primary coils _p r_ are connected, respectively, to the
mains F E, which are electrically connected with the two coils of the
generator. The cross-circuit wires _l m_, making these connections, are
then connected to the common return-wire D. The secondary coils _p' p''_
are in circuits _n o_, including, for example, incandescent lamps. Only
one converter is shown entire in this figure, the others being
illustrated diagrammatically.

When motors or converters are to be run in series, the two wires E F are
led from the generator to the coils of the first motor or converter,
then continued on to the next, and so on through the whole series, and
are then joined to the single wire D, which completes both circuits
through the generator. This is shown in Fig. 24, in which J I represent
the two coils or sets of coils of the motors.

There are, of course, other conditions under which the same idea may be
carried out. For example, in case the motor and generator each has three
independent circuits, one terminal of each circuit is connected to a
line-wire, and the other three terminals to a common return-conductor.
This arrangement will secure similar results to those attained with a
generator and motor having but two independent circuits, as above
described.

When applied to such machines and motors as have three or more induced
circuits with a common electrical joint, the three or more terminals of
the generator would be simply connected to those of the motor. Mr.
Tesla states, however, that the results obtained in this manner show a
lower efficiency than do the forms dwelt upon more fully above.




CHAPTER V.

UTILIZING FAMILIAR TYPES OF GENERATOR OF THE CONTINUOUS CURRENT TYPE.


The preceding descriptions have assumed the use of alternating current
generators in which, in order to produce the progressive movement of the
magnetic poles, or of the resultant attraction of independent field
magnets, the current generating coils are independent or separate. The
ordinary forms of continuous current dynamos may, however, be employed
for the same work, in accordance with a method of adaptation devised by
Mr. Tesla. As will be seen, the modification involves but slight changes
in their construction, and presents other elements of economy.

On the shaft of a given generator, either in place of or in addition to
the regular commutator, are secured as many pairs of insulated
collecting-rings as there are circuits to be operated. Now, it will be
understood that in the operation of any dynamo electric generator the
currents in the coils in their movement through the field of force
undergo different phases--that is to say, at different positions of the
coils the currents have certain directions and certain strengths--and
that in the Tesla motors or transformers it is necessary that the
currents in the energizing coils should undergo a certain order of
variations in strength and direction. Hence, the further step--viz., the
connection between the induced or generating coils of the machine and
the contact-rings from which the currents are to be taken off--will be
determined solely by what order of variations of strength and direction
in the currents is desired for producing a given result in the
electrical translating device. This may be accomplished in various ways;
but in the drawings we give typical instances only of the best and most
practicable ways of applying the invention to three of the leading types
of machines in widespread use, in order to illustrate the principle.

Fig. 25 is a diagram illustrative of the mode of applying the invention
to the well-known type of "closed" or continuous circuit machines. Fig.
26 is a similar diagram embodying an armature with separate coils
connected diametrically, or what is generally called an "open-circuit"
machine. Fig. 27 is a diagram showing the application of the invention
to a machine the armature-coils of which have a common joint.

[Illustration: FIG. 25.]

Referring to Fig. 25, let A represent a Tesla motor or transformer
which, for convenience, we will designate as a "converter." It consists
of an annular core, B, wound with four independent coils, C and D, those
diametrically opposite being connected together so as to co-operate in
pairs in establishing free poles in the ring, the tendency of each pair
being to fix the poles at ninety degrees from the other. There may be an
armature, E, within the ring, which is wound with coils closed upon
themselves. The object is to pass through coils C D currents of such
relative strength and direction as to produce a progressive shifting or
movement of the points of maximum magnetic effect around the ring, and
to thereby maintain a rotary movement of the armature. There are
therefore secured to the shaft F of the generator, four insulated
contact-rings, _a b c d_, upon which bear the collecting-brushes
_a' b' c' d'_, connected by wires G G H H, respectively, with the
terminals of coils C and D.

Assume, for sake of illustration, that the coils D D are to receive the
maximum and coils C C at the same instant the minimum current, so that
the polar line may be midway between the coils D D. The rings _a b_
would therefore be connected to the continuous armature-coil at its
neutral points with respect to the field, or the point corresponding
with that of the ordinary commutator brushes, and between which exists
the greatest difference of potential; while rings _c d_ would be
connected to two points in the coil, between which exists no difference
of potential. The best results will be obtained by making these
connections at points equidistant from one another, as shown. These
connections are easiest made by using wires L between the rings and the
loops or wires J, connecting the coil I to the segments of the
commutator K. When the converters are made in this manner, it is evident
that the phases of the currents in the sections of the generator coil
will be reproduced in the converter coils. For example, after turning
through an arc of ninety degrees the conductors L L, which before
conveyed the maximum current, will receive the minimum current by reason
of the change in the position of their coils, and it is evident that for
the same reason the current in these coils has gradually fallen from the
maximum to the minimum in passing through the arc of ninety degrees. In
this special plan of connections, the rotation of the magnetic poles of
the converter will be synchronous with that of the armature coils of the
generator, and the result will be the same, whether the energizing
circuits are derivations from a continuous armature coil or from
independent coils, as in Mr. Tesla's other devices.

In Fig. 25, the brushes M M are shown in dotted lines in their proper
normal position. In practice these brushes may be removed from the
commutator and the field of the generator excited by an external source
of current; or the brushes may be allowed to remain on the commutator
and to take off a converted current to excite the field, or to be used
for other purposes.

In a certain well-known class of machines known as the "open circuit,"
the armature contains a number of coils the terminals of which connect
to commutator segments, the coils being connected across the armature in
pairs. This type of machine is represented in Fig. 26. In this machine
each pair of coils goes through the same phases as the coils in some of
the generators already shown, and it is obviously only necessary to
utilize them in pairs or sets to operate a Tesla converter by extending
the segments of the commutators belonging to each pair of coils and
causing a collecting brush to bear on the continuous portion of each
segment. In this way two or more circuits may be taken off from the
generator, each including one or more pairs or sets of coils as may be
desired.

[Illustration: FIG. 26.]

[Illustration: FIG. 27.]

In Fig. 26 I I represent the armature coils, T T the poles of the field
magnet, and F the shaft carrying the commutators, which are extended to
form continuous portions _a b c d_. The brushes bearing on the
continuous portions for taking off the alternating currents are
represented by _a' b' c' d'_. The collecting brushes, or those which may
be used to take off the direct current, are designated by M M. Two pairs
of the armature coils and their commutators are shown in the figure as
being utilized; but all may be utilized in a similar manner.

There is another well-known type of machine in which three or more
coils, A' B' C', on the armature have a common joint, the free ends
being connected to the segments of a commutator. This form of generator
is illustrated in Fig. 27. In this case each terminal of the generator
is connected directly or in derivation to a continuous ring, _a b c_,
and collecting brushes, _a' b' c'_, bearing thereon, take off the
alternating currents that operate the motor. It is preferable in this
case to employ a motor or transformer with three energizing coils, A''
B'' C'', placed symmetrically with those of the generator, and the
circuits from the latter are connected to the terminals of such coils
either directly--as when they are stationary--or by means of brushes
_e'_ and contact rings _e_. In this, as in the other cases, the ordinary
commutator may be used on the generator, and the current taken from it
utilized for exciting the generator field-magnets or for other
purposes.




CHAPTER VI.

METHOD OF OBTAINING DESIRED SPEED OF MOTOR OR GENERATOR.


With the object of obtaining the desired speed in motors operated by
means of alternating currents of differing phase, Mr. Tesla has devised
various plans intended to meet the practical requirements of the case,
in adapting his system to types of multipolar alternating current
machines yielding a large number of current reversals for each
revolution.

For example, Mr. Tesla has pointed out that to adapt a given type of
alternating current generator, you may couple rigidly two complete
machines, securing them together in such a way that the requisite
difference in phase will be produced; or you may fasten two armatures to
the same shaft within the influence of the same field and with the
requisite angular displacement to yield the proper difference in phase
between the two currents; or two armatures may be attached to the same
shaft with their coils symmetrically disposed, but subject to the
influence of two sets of field magnets duly displaced; or the two sets
of coils may be wound on the same armature alternately or in such manner
that they will develop currents the phases of which differ in time
sufficiently to produce the rotation of the motor.

Another method included in the scope of the same idea, whereby a single
generator may run a number of motors either at its own rate of speed or
all at different speeds, is to construct the motors with fewer poles
than the generator, in which case their speed will be greater than that
of the generator, the rate of speed being higher as the number of their
poles is relatively less. This may be understood from an example, taking
a generator that has two independent generating coils which revolve
between two pole pieces oppositely magnetized; and a motor with
energizing coils that produce at any given time two magnetic poles in
one element that tend to set up a rotation of the motor. A generator
thus constructed yields four reversals, or impulses, in each
revolution, two in each of its independent circuits; and the effect upon
the motor is to shift the magnetic poles through three hundred and sixty
degrees. It is obvious that if the four reversals in the same order
could be produced by each half-revolution of the generator the motor
would make two revolutions to the generator's one. This would be readily
accomplished by adding two intermediate poles to the generator or
altering it in any of the other equivalent ways above indicated. The
same rule applies to generators and motors with multiple poles. For
instance, if a generator be constructed with two circuits, each of which
produces twelve reversals of current to a revolution, and these currents
be directed through the independent energizing-coils of a motor, the
coils of which are so applied as to produce twelve magnetic poles at all
times, the rotation of the two will be synchronous; but if the
motor-coils produce but six poles, the movable element will be rotated
twice while the generator rotates once; or if the motor have four poles,
its rotation will be three times as fast as that of the generator.

[Illustration: FIG. 28.]

[Illustration: FIG. 29.]

These features, so far as necessary to an understanding of the
principle, are here illustrated. Fig. 28 is a diagrammatic illustration
of a generator constructed in accordance with the invention. Fig. 29 is
a similar view of a correspondingly constructed motor. Fig. 30 is a
diagram of a generator of modified construction. Fig. 31 is a diagram of
a motor of corresponding character. Fig. 32 is a diagram of a system
containing a generator and several motors adapted to run at various
speeds.

In Fig. 28, let C represent a cylindrical armature core wound
longitudinally with insulated coils A A, which are connected up in
series, the terminals of the series being connected to collecting-rings
_a a_ on the shaft G. By means of this shaft the armature is mounted to
rotate between the poles of an annular field-magnet D, formed with polar
projections wound with coils E, that magnetize the said projections. The
coils E are included in the circuit of a generator F, by means of which
the field-magnet is energized. If thus constructed, the machine is a
well-known form of alternating-current generator. To adapt it to his
system, however, Mr. Tesla winds on armature C a second set of coils B B
intermediate to the first, or, in other words, in such positions that
while the coils of one set are in the relative positions to the poles of
the field-magnet to produce the maximum current, those of the other set
will be in the position in which they produce the minimum current. The
coils B are connected, also, in series and to two connecting-rings,
secured generally to the shaft at the opposite end of the armature.

[Illustration: FIG. 30.]

[Illustration: FIG. 31.]

The motor shown in Fig. 29 has an annular field-magnet H, with four
pole-pieces wound with coils I. The armature is constructed similarly to
the generator, but with two sets of two coils in closed circuits to
correspond with the reduced number of magnetic poles in the field. From
the foregoing it is evident that one revolution of the armature of the
generator producing eight current impulses in each circuit will produce
two revolutions of the motor-armature.

The application of the principle of this invention is not, however,
confined to any particular form of machine. In Figs. 30 and 31 a
generator and motor of another well-known type are shown. In Fig. 30, J
J are magnets disposed in a circle and wound with coils K, which are in
circuit with a generator which supplies the current that maintains the
field of force. In the usual construction of these machines the
armature-conductor L is carried by a suitable frame, so as to be rotated
in face of the magnets J J, or between these magnets and another similar
set in front of them. The magnets are energized so as to be of
alternately opposite polarity throughout the series, so that as the
conductor C is rotated the current impulses combine or are added to one
another, those produced by the conductor in any given position being all
in the same direction. To adapt such a machine to his system, Mr. Tesla
adds a second set of induced conductors M, in all respects similar to
the first, but so placed in reference to it that the currents produced
in each will differ by a quarter-phase. With such relations it is
evident that as the current decreases in conductor L it increases in
conductor M, and conversely, and that any of the forms of Tesla motor
invented for use in this system may be operated by such a generator.

Fig. 31 is intended to show a motor corresponding to the machine in Fig.
30. The construction of the motor is identical with that of the
generator, and if coupled thereto it will run synchronously therewith.
J' J' are the field-magnets, and K' the coils thereon. L' is one of the
armature-conductors and M' the other.

Fig. 32 shows in diagram other forms of machine. The generator N in this
case is shown as consisting of a stationary ring O, wound with
twenty-four coils P P', alternate coils being connected in series in two
circuits. Within this ring is a disc or drum Q, with projections Q'
wound with energizing-coils included in circuit with a generator R. By
driving this disc or cylinder alternating currents are produced in the
coils P and P', which are carried off to run the several motors.

The motors are composed of a ring or annular field-magnet S, wound with
two sets of energizing-coils T T', and armatures U, having projections
U' wound with coils V, all connected in series in a closed circuit or
each closed independently on itself.

Suppose the twelve generator-coils P are wound alternately in opposite
directions, so that any two adjacent coils of the same set tend to
produce a free pole in the ring O between them and the twelve coils P'
to be similarly wound. A single revolution of the disc or cylinder Q,
the twelve polar projections of which are of opposite polarity, will
therefore produce twelve current impulses in each of the circuits W W'.
Hence the motor X, which has sixteen coils or eight free poles, will
make one and a half turns to the generator's one. The motor Y, with
twelve coils or six poles, will rotate with twice the speed of the
generator, and the motor Z, with eight coils or four poles, will revolve
three times as fast as the generator. These multipolar motors have a
peculiarity which may be often utilized to great advantage. For example,
in the motor X, Fig. 32, the eight poles may be either alternately
opposite or there may be at any given time alternately two like and two
opposite poles. This is readily attained by making the proper electrical
connections. The effect of such a change, however, would be the same as
reducing the number of poles one-half, and thereby doubling the speed
of any given motor.

[Illustration: FIG. 32.]

It is obvious that the Tesla electrical transformers which have
independent primary currents may be used with the generators described.
It may also be stated with respect to the devices we now describe that
the most perfect and harmonious action of the generators and motors is
obtained when the numbers of the poles of each are even and not odd. If
this is not the case, there will be a certain unevenness of action which
is the less appreciable as the number of poles is greater; although this
may be in a measure corrected by special provisions which it is not here
necessary to explain. It also follows, as a matter of course, that if
the number of the poles of the motor be greater than that of the
generator the motor will revolve at a slower speed than the generator.

In this chapter, we may include a method devised by Mr. Tesla for
avoiding the very high speeds which would be necessary with large
generators. In lieu of revolving the generator armature at a high rate
of speed, he secures the desired result by a rotation of the magnetic
poles of one element of the generator, while driving the other at a
different speed. The effect is the same as that yielded by a very high
rate of rotation.

In this instance, the generator which supplies the current for operating
the motors or transformers consists of a subdivided ring or annular core
wound with four diametrically-opposite coils, E E', Fig. 33. Within the
ring is mounted a cylindrical armature-core wound longitudinally with
two independent coils, F F', the ends of which lead, respectively, to
two pairs of insulated contact or collecting rings, D D' G G', on the
armature shaft. Collecting brushes _d d' g g'_ bear upon these rings,
respectively, and convey the currents through the two independent
line-circuits M M'. In the main line there may be included one or more
motors or transformers, or both. If motors be used, they are of the
usual form of Tesla construction with independent coils or sets of coils
J J', included, respectively, in the circuits M M'. These
energizing-coils are wound on a ring or annular field or on pole pieces
thereon, and produce by the action of the alternating currents passing
through them a progressive shifting of the magnetism from pole to pole.
The cylindrical armature H of the motor is wound with two coils at right
angles, which form independent closed circuits.

If transformers be employed, one set of the primary coils, as N N, wound
on a ring or annular core is connected to one circuit, as M', and the
other primary coils, N N', to the circuit M. The secondary coils K K'
may then be utilized for running groups of incandescent lamps P P'.

[Illustration: FIG. 33.]

With this generator an exciter is employed. This consists of two poles,
A A, of steel permanently magnetized, or of iron excited by a battery or
other generator of continuous currents, and a cylindrical armature core
mounted on a shaft, B, and wound with two longitudinal coils, C C'. One
end of each of these coils is connected to the collecting-rings _b c_,
respectively, while the other ends are both connected to a ring, _a_.
Collecting-brushes _b' c'_ bear on the rings _b c_, respectively, and
conductors L L convey the currents therefrom through the coils E and E
of the generator. L' is a common return-wire to brush _a'_. Two
independent circuits are thus formed, one including coils C of the
exciter and E E of the generator, the other coils C' of the exciter and
E' E' of the generator. It results from this that the operation of the
exciter produces a progressive movement of the magnetic poles of the
annular field-core of the generator, the shifting or rotary movement of
the poles being synchronous with the rotation of the exciter armature.
Considering the operative conditions of a system thus established, it
will be found that when the exciter is driven so as to energize the
field of the generator, the armature of the latter, if left free to
turn, would rotate at a speed practically the same as that of the
exciter. If under such conditions the coils F F' of the generator
armature be closed upon themselves or short-circuited, no currents, at
least theoretically, will be generated in these armature coils. In
practice the presence of slight currents is observed, the existence of
which is attributable to more or less pronounced fluctuations in the
intensity of the magnetic poles of the generator ring. So, if the
armature-coils F F' be closed through the motor, the latter will not be
turned as long as the movement of the generator armature is synchronous
with that of the exciter or of the magnetic poles of its field. If, on
the contrary, the speed of the generator armature be in any way checked,
so that the shifting or rotation of the poles of the field becomes
relatively more rapid, currents will be induced in the armature coils.
This obviously follows from the passing of the lines of force across the
armature conductors. The greater the speed of rotation of the magnetic
poles relatively to that of the armature the more rapidly the currents
developed in the coils of the latter will follow one another, and the
more rapidly the motor will revolve in response thereto, and this
continues until the armature generator is stopped entirely, as by a
brake, when the motor, if properly constructed, runs at the speed with
which the magnetic poles of the generator rotate.

The effective strength of the currents developed in the armature coils
of the generator is dependent upon the strength of the currents
energizing the generator and upon the number of rotations per unit of
time of the magnetic poles of the generator; hence the speed of the
motor armature will depend in all cases upon the relative speeds of the
armature of the generator and of its magnetic poles. For example, if the
poles are turned two thousand times per unit of time and the armature is
turned eight hundred, the motor will turn twelve hundred times, or
nearly so. Very slight differences of speed may be indicated by a
delicately balanced motor.

Let it now be assumed that power is applied to the generator armature to
turn it in a direction opposite to that in which its magnetic poles
rotate. In such case the result would be similar to that produced by a
generator the armature and field magnets of which are rotated in
opposite directions, and by reason of these conditions the motor
armature will turn at a rate of speed equal to the sum of the speeds of
the armature and magnetic poles of the generator, so that a
comparatively low speed of the generator armature will produce a high
speed in the motor.

It will be observed in connection with this system that on diminishing
the resistance of the external circuit of the generator armature by
checking the speed of the motor or by adding translating devices in
multiple arc in the secondary circuit or circuits of the transformer the
strength of the current in the armature circuit is greatly increased.
This is due to two causes: first, to the great differences in the speeds
of the motor and generator, and, secondly, to the fact that the
apparatus follows the analogy of a transformer, for, in proportion as
the resistance of the armature or secondary circuits is reduced, the
strength of the currents in the field or primary circuits of the
generator is increased and the currents in the armature are augmented
correspondingly. For similar reasons the currents in the armature-coils
of the generator increase very rapidly when the speed of the armature is
reduced when running in the same direction as the magnetic poles or
conversely.

It will be understood from the above description that the
generator-armature may be run in the direction of the shifting of the
magnetic poles, but more rapidly, and that in such case the speed of the
motor will be equal to the difference between the two rates.




CHAPTER VII.

REGULATOR FOR ROTARY CURRENT MOTORS.


An interesting device for regulating and reversing has been devised by
Mr. Tesla for the purpose of varying the speed of polyphase motors. It
consists of a form of converter or transformer with one element capable
of movement with respect to the other, whereby the inductive relations
may be altered, either manually or automatically, for the purpose of
varying the strength of the induced current. Mr. Tesla prefers to
construct this device in such manner that the induced or secondary
element may be movable with respect to the other; and the invention, so
far as relates merely to the construction of the device itself,
consists, essentially, in the combination, with two opposite magnetic
poles, of an armature wound with an insulated coil and mounted on a
shaft, whereby it may be turned to the desired extent within the field
produced by the poles. The normal position of the core of the secondary
element is that in which it most completely closes the magnetic circuit
between the poles of the primary element, and in this position its coil
is in its most effective position for the inductive action upon it of
the primary coils; but by turning the movable core to either side, the
induced currents delivered by its coil become weaker until, by a
movement of the said core and coil through 90 deg., there will be no current
delivered.

Fig. 34 is a view in side elevation of the regulator. Fig. 35 is a
broken section on line _x x_ of Fig. 34. Fig. 36 is a diagram
illustrating the most convenient manner of applying the regulator to
ordinary forms of motors, and Fig. 37 is a similar diagram illustrating
the application of the device to the Tesla alternating-current motors.
The regulator may be constructed in many ways to secure the desired
result; but that which is, perhaps, its best form is shown in Figs. 34
and 35.

A represents a frame of iron. B B are the cores of the inducing or
primary coils C C. D is a shaft mounted on the side bars, D', and on
which is secured a sectional iron core, E, wound with an induced or
secondary coil, F, the convolutions of which are parallel with the axis
of the shaft. The ends of the core are rounded off so as to fit closely
in the space between the two poles and permit the core E to be turned to
and held at any desired point. A handle, G, secured to the projecting
end of the shaft D, is provided for this purpose.

[Illustration: FIG. 34.]

[Illustration: FIG. 35.]

In Fig. 36 let H represent an ordinary alternating current generator,
the field-magnets of which are excited by a suitable source of current,
I. Let J designate an ordinary form of electromagnetic motor provided
with an armature, K, commutator L, and field-magnets M. It is well known
that such a motor, if its field-magnet cores be divided up into
insulated sections, may be practically operated by an alternating
current; but in using this regulator with such a motor, Mr. Tesla
includes one element of the motor only--say the armature-coils--in the
main circuit of the generator, making the connections through the
brushes and the commutator in the usual way. He also includes one of the
elements of the regulator--say the stationary coils--in the same
circuit, and in the circuit with the secondary or movable coil of the
regulator he connects up the field-coils of the motor. He also prefers
to use flexible conductors to make the connections from the secondary
coil of the regulator, as he thereby avoids the use of sliding contacts
or rings without interfering with the requisite movement of the core E.

If the regulator be in its normal position, or that in which its
magnetic circuit is most nearly closed, it delivers its maximum induced
current, the phases of which so correspond with those of the primary
current that the motor will run as though both field and armature were
excited by the main current.

[Illustration: FIG. 36.]

To vary the speed of the motor to any rate between the minimum and
maximum rates, the core E and coils F are turned in either direction to
an extent which produces the desired result, for in its normal position
the convolutions of coil F embrace the maximum number of lines of force,
all of which act with the same effect upon the coil; hence it will
deliver its maximum current; but by turning the coil F out of its
position of maximum effect the number of lines of force embraced by it
is diminished. The inductive effect is therefore impaired, and the
current delivered by coil F will continue to diminish in proportion to
the angle at which the coil F is turned until, after passing through an
angle of ninety degrees, the convolutions of the coil will be at right
angles to those of coils C C, and the inductive effect reduced to a
minimum.

Incidentally to certain constructions, other causes may influence the
variation in the strength of the induced currents. For example, in the
present case it will be observed that by the first movement of coil F a
certain portion of its convolutions are carried beyond the line of the
direct influence of the lines of force, and that the magnetic path or
circuit for the lines is impaired; hence the inductive effect would be
reduced. Next, that after moving through a certain angle, which is
obviously determined by the relative dimensions of the bobbin or coil F,
diagonally opposite portions of the coil will be simultaneously included
in the field, but in such positions that the lines which produce a
current-impulse in one portion of the coil in a certain direction will
produce in the diagonally opposite portion a corresponding impulse in
the opposite direction; hence portions of the current will neutralize
one another.

As before stated, the mechanical construction of the device may be
greatly varied; but the essential conditions of the principle will be
fulfilled in any apparatus in which the movement of the elements with
respect to one another effects the same results by varying the inductive
relations of the two elements in a manner similar to that described.

[Illustration: FIG. 37.]

It may also be stated that the core E is not indispensable to the
operation of the regulator; but its presence is obviously beneficial.
This regulator, however, has another valuable property in its capability
of reversing the motor, for if the coil F be turned through a
half-revolution, the position of its convolutions relatively to the two
coils C C and to the lines of force is reversed, and consequently the
phases of the current will be reversed. This will produce a rotation of
the motor in an opposite direction. This form of regulator is also
applied with great advantage to Mr. Tesla's system of utilizing
alternating currents, in which the magnetic poles of the field of a
motor are progressively shifted by means of the combined effects upon
the field of magnetizing coils included in independent circuits, through
which pass alternating currents in proper order and relations to each
other.

In Fig. 37, let P represent a Tesla generator having two independent
coils, P' and P'', on the armature, and T a diagram of a motor having
two independent energizing coils or sets of coils, R R'. One of the
circuits from the generator, as S' S', includes one set, R' R', of the
energizing coils of the motor, while the other circuit, as S S, includes
the primary coils of the regulator. The secondary coil of the regulator
includes the other coils, R R, of the motor.

While the secondary coil of the regulator is in its normal position, it
produces its maximum current, and the maximum rotary effect is imparted
to the motor; but this effect will be diminished in proportion to the
angle at which the coil F of the regulator is turned. The motor will
also be reversed by reversing the position of the coil with reference to
the coils C C, and thereby reversing the phases of the current produced
by the generator. This changes the direction of the movement of the
shifting poles which the armature follows.

One of the main advantages of this plan of regulation is its economy of
power. When the induced coil is generating its maximum current, the
maximum amount of energy in the primary coils is absorbed; but as the
induced coil is turned from its normal position the self-induction of
the primary-coils reduces the expenditure of energy and saves power.

It is obvious that in practice either coils C C or coil F may be used as
primary or secondary, and it is well understood that their relative
proportions may be varied to produce any desired difference or
similarity in the inducing and induced currents.




CHAPTER VIII.

SINGLE CIRCUIT, SELF-STARTING SYNCHRONIZING MOTORS.


In the first chapters of this section we have, bearing in mind the broad
underlying principle, considered a distinct class of motors, namely,
such as require for their operation a special generator capable of
yielding currents of differing phase. As a matter of course, Mr. Tesla
recognizing the desirability of utilizing his motors in connection with
ordinary systems of distribution, addressed himself to the task of
inventing various methods and ways of achieving this object. In the
succeeding chapters, therefore, we witness the evolution of a number of
ideas bearing upon this important branch of work. It must be obvious to
a careful reader, from a number of hints encountered here and there,
that even the inventions described in these chapters to follow do not
represent the full scope of the work done in these lines. They might,
indeed, be regarded as exemplifications.

We will present these various inventions in the order which to us
appears the most helpful to an understanding of the subject by the
majority of readers. It will be naturally perceived that in offering a
series of ideas of this nature, wherein some of the steps or links are
missing, the descriptions are not altogether sequential; but any one who
follows carefully the main drift of the thoughts now brought together
will find that a satisfactory comprehension of the principles can be
gained.

As is well known, certain forms of alternating-current machines have the
property, when connected in circuit with an alternating current
generator, of running as a motor in synchronism therewith; but, while
the alternating current will run the motor after it has attained a rate
of speed synchronous with that of the generator, it will not start it.
Hence, in all instances heretofore where these "synchronizing motors,"
as they are termed, have been run, some means have been adopted to bring
the motors up to synchronism with the generator, or approximately so,
before the alternating current of the generator is applied to drive
them. In some instances mechanical appliances have been utilized for
this purpose. In others special and complicated forms of motor have been
constructed. Mr. Tesla has discovered a much more simple method or plan
of operating synchronizing motors, which requires practically no other
apparatus than the motor itself. In other words, by a certain change in
the circuit connections of the motor he converts it at will from a
double circuit motor, or such as have been already described, and which
will start under the action of an alternating current, into a
synchronizing motor, or one which will be run by the generator only when
it has reached a certain speed of rotation synchronous with that of the
generator. In this manner he is enabled to extend very greatly the
applications of his system and to secure all the advantages of both
forms of alternating current motor.

The expression "synchronous with that of the generator," is used here in
its ordinary acceptation--that is to say, a motor is said to synchronize
with the generator when it preserves a certain relative speed determined
by its number of poles and the number of alternations produced per
revolution of the generator. Its actual speed, therefore, may be faster
or slower than that of the generator; but it is said to be synchronous
so long as it preserves the same relative speed.

In carrying out this invention Mr. Tesla constructs a motor which has a
strong tendency to synchronism with the generator. The construction
preferred is that in which the armature is provided with polar
projections. The field-magnets are wound with two sets of coils, the
terminals of which are connected to a switch mechanism, by means of
which the line-current may be carried directly through these coils or
indirectly through paths by which its phases are modified. To start such
a motor, the switch is turned on to a set of contacts which includes in
one motor circuit a dead resistance, in the other an inductive
resistance, and, the two circuits being in derivation, it is obvious
that the difference in phase of the current in such circuits will set up
a rotation of the motor. When the speed of the motor has thus been
brought to the desired rate the switch is shifted to throw the main
current directly through the motor-circuits, and although the currents
in both circuits will now be of the same phase the motor will continue
to revolve, becoming a true synchronous motor. To secure greater
efficiency, the armature or its polar projections are wound with coils
closed on themselves.

In the accompanying diagrams, Fig. 38 illustrates the details of the
plan above set forth, and Figs. 39 and 40 modifications of the same.

[Illustration: FIGS. 38, 39 and 40.]

Referring to Fig. 38, let A designate the field-magnets of a motor, the
polar projections of which are wound with coils B C included in
independent circuits, and D the armature with polar projections wound
with coils E closed upon themselves, the motor in these respects being
similar in construction to those described already, but having on
account of the polar projections on the armature core, or other similar
and well-known features, the properties of a synchronizing-motor. L L'
represents the conductors of a line from an alternating current
generator G.

Near the motor is placed a switch the action of which is that of the one
shown in the diagrams, which is constructed as follows: F F' are two
conducting plates or arms, pivoted at their ends and connected by an
insulating cross-bar, H, so as to be shifted in parallelism. In the path
of the bars F F' is the contact 2, which forms one terminal of the
circuit through coils C, and the contact 4, which is one terminal of the
circuit through coils B. The opposite end of the wire of coils C is
connected to the wire L or bar F', and the corresponding end of coils B
is connected to wire L' and bar F; hence if the bars be shifted so as to
bear on contacts 2 and 4 both sets of coils B C will be included in the
circuit L L' in multiple arc or derivation. In the path of the levers F
F' are two other contact terminals, 1 and 3. The contact 1 is connected
to contact 2 through an artificial resistance, I, and contact 3 with
contact 4 through a self-induction coil, J, so that when the switch
levers are shifted upon the points 1 and 3 the circuits of coils B and C
will be connected in multiple arc or derivation to the circuit L L', and
will include the resistance and self-induction coil respectively. A
third position of the switch is that in which the levers F and F' are
shifted out of contact with both sets of points. In this case the motor
is entirely out of circuit.

The purpose and manner of operating the motor by these devices are as
follows: The normal position of the switch, the motor being out of
circuit, is off the contact points. Assuming the generator to be
running, and that it is desired to start the motor, the switch is
shifted until its levers rest upon points 1 and 3. The two
motor-circuits are thus connected with the generator circuit; but by
reason of the presence of the resistance I in one and the self-induction
coil J in the other the coincidence of the phases of the current is
disturbed sufficiently to produce a progression of the poles, which
starts the motor in rotation. When the speed of the motor has run up to
synchronism with the generator, or approximately so, the switch is
shifted over upon the points 2 and 4, thus cutting out the coils I and
J, so that the currents in both circuits have the same phase; but the
motor now runs as a synchronous motor.

It will be understood that when brought up to speed the motor will run
with only one of the circuits B or C connected with the main or
generator circuit, or the two circuits may be connected in series. This
latter plan is preferable when a current having a high number of
alternations per unit of time is employed to drive the motor. In such
case the starting of the motor is more difficult, and the dead and
inductive resistances must take up a considerable proportion of the
electromotive force of the circuits. Generally the conditions are so
adjusted that the electromotive force used in each of the motor circuits
is that which is required to operate the motor when its circuits are in
series. The plan followed in this case is illustrated in Fig. 39. In
this instance the motor has twelve poles and the armature has polar
projections D wound with closed coils E. The switch used is of
substantially the same construction as that shown in the previous
figure. There are, however, five contacts, designated as 5, 6, 7, 8, and
9. The motor-circuits B C, which include alternate field-coils, are
connected to the terminals in the following order: One end of circuit C
is connected to contact 9 and to contact 5 through a dead resistance, I.
One terminal of circuit B is connected to contact 7 and to contact 6
through a self-induction coil, J. The opposite terminals of both
circuits are connected to contact 8.

One of the levers, as F, of the switch is made with an extension, _f_,
or otherwise, so as to cover both contacts 5 and 6 when shifted into the
position to start the motor. It will be observed that when in this
position and with lever F' on contact 8 the current divides between the
two circuits B C, which from their difference in electrical character
produce a progression of the poles that starts the motor in rotation.
When the motor has attained the proper speed, the switch is shifted so
that the levers cover the contacts 7 and 9, thereby connecting circuits
B and C in series. It is found that by this disposition the motor is
maintained in rotation in synchronism with the generator. This principle
of operation, which consists in converting by a change of connections or
otherwise a double-circuit motor, or one operating by a progressive
shifting of the poles, into an ordinary synchronizing motor may be
carried out in many other ways. For instance, instead of using the
switch shown in the previous figures, we may use a temporary ground
circuit between the generator and motor, in order to start the motor, in
substantially the manner indicated in Fig. 40. Let G in this figure
represent an ordinary alternating-current generator with, say, two
poles, M M', and an armature wound with two coils, N N', at right angles
and connected in series. The motor has, for example, four poles wound
with coils B C, which are connected in series, and an armature with
polar projections D wound with closed coils E E. From the common joint
or union between the two circuits of both the generator and the motor an
earth connection is established, while the terminals or ends of these
circuits are connected to the line. Assuming that the motor is a
synchronizing motor or one that has the capability of running in
synchronism with the generator, but not of starting, it may be started
by the above-described apparatus by closing the ground connection from
both generator and motor. The system thus becomes one with a two-circuit
generator and motor, the ground forming a common return for the currents
in the two circuits L and L'. When by this arrangement of circuits the
motor is brought to speed, the ground connection is broken between the
motor or generator, or both, ground-switches P P' being employed for
this purpose. The motor then runs as a synchronizing motor.

In describing the main features which constitute this invention
illustrations have necessarily been omitted of the appliances used in
conjunction with the electrical devices of similar systems--such, for
instance, as driving-belts, fixed and loose pulleys for the motor, and
the like; but these are matters well understood.

Mr. Tesla believes he is the first to operate electro-magnetic motors by
alternating currents in any of the ways herein described--that is to
say, by producing a progressive movement or rotation of their poles or
points of greatest magnetic attraction by the alternating currents until
they have reached a given speed, and then by the same currents producing
a simple alternation of their poles, or, in other words, by a change in
the order or character of the circuit connections to convert a motor
operating on one principle to one operating on another.




CHAPTER IX.

CHANGE FROM DOUBLE CURRENT TO SINGLE CURRENT MOTOR.


A description is given elsewhere of a method of operating alternating
current motors by first rotating their magnetic poles until they have
attained synchronous speed, and then alternating the poles. The motor is
thus transformed, by a simple change of circuit connections from one
operated by the action of two or more independent energizing currents to
one operated either by a single current or by several currents acting as
one. Another way of doing this will now be described.

At the start the magnetic poles of one element or field of the motor are
progressively shifted by alternating currents differing in phase and
passed through independent energizing circuits, and short circuit the
coils of the other element. When the motor thus started reaches or
passes the limit of speed synchronous with the generator, Mr. Tesla
connects up the coils previously short-circuited with a source of direct
current and by a change of the circuit connections produces a simple
alternation of the poles. The motor then continues to run in synchronism
with the generator. The motor here shown in Fig. 41 is one of the
ordinary forms, with field-cores either laminated or solid and with a
cylindrical laminated armature wound, for example, with the coils A B at
right angles. The shaft of the armature carries three collecting or
contact rings C D E. (Shown, for better illustration, as of different
diameters.)

One end of coil A connects to one ring, as C, and one end of coil B
connects with ring D. The remaining ends are connected to ring E.
Collecting springs or brushes F G H bear upon the rings and lead to the
contacts of a switch, to be presently described. The field-coils have
their terminals in binding-posts K K, and may be either closed upon
themselves or connected with a source of direct current L, by means of a
switch M. The main or controlling switch has five contacts _a b c d e_
and two levers _f g_, pivoted and connected by an insulating cross-bar
_h_, so as to move in parallelism. These levers are connected to the
line wires from a source of alternating currents N. Contact _a_ is
connected to brush G and coil B through a dead resistance R and wire P.
Contact _b_ is connected with brush F and coil A through a
self-induction coil S and wire O. Contacts _c_ and _e_ are connected to
brushes G F, respectively, through the wires P O, and contact _d_ is
directly connected with brush H. The lever _f_ has a widened end, which
may span the contacts _a b_. When in such position and with lever _g_ on
contact _d_, the alternating currents divide between the two
motor-coils, and by reason of their different self-induction a
difference of current-phase is obtained that starts the motor in
rotation. In starting, the field-coils are short circuited.

[Illustration: FIG. 41.]

When the motor has attained the desired speed, the switch is shifted to
the position shown in dotted lines--that is to say, with the levers _f
g_ resting on points _c e_. This connects up the two armature coils in
series, and the motor will then run as a synchronous motor. The
field-coils are thrown into circuit with the direct current source when
the main switch is shifted.




CHAPTER X.

MOTOR WITH "CURRENT LAG" ARTIFICIALLY SECURED.


One of the general ways followed by Mr. Tesla in developing his rotary
phase motors is to produce practically independent currents differing
primarily in phase and to pass these through the motor-circuits. Another
way is to produce a single alternating current, to divide it between the
motor-circuits, and to effect artificially a lag in one of these
circuits or branches, as by giving to the circuits different
self-inductive capacity, and in other ways. In the former case, in which
the necessary difference of phase is primarily effected in the
generation of currents, in some instances, the currents are passed
through the energizing coils of both elements of the motor--the field
and armature; but a further result or modification may be obtained by
doing this under the conditions hereinafter specified in the case of
motors in which the lag, as above stated, is artificially secured.

Figs. 42 to 47, inclusive, are diagrams of different ways in which the
invention is carried out; and Fig. 48, a side view of a form of motor
used by Mr. Tesla for this purpose.

[Illustration: FIGS. 42, 43 and 44.]

A B in Fig. 42 indicate the two energizing circuits of a motor, and C D
two circuits on the armature. Circuit or coil A is connected in series
with circuit or coil C, and the two circuits B D are similarly
connected. Between coils A and C is a contact-ring _e_, forming one
terminal of the latter, and a brush _a_, forming one terminal of the
former. A ring _d_ and brush _c_ similarly connect coils B and D. The
opposite terminals of the field-coils connect to one binding post _h_ of
the motor, and those of the armature coils are similarly connected to
the opposite binding post _i_ through a contact-ring _f_ and brush _g_.
Thus each motor-circuit while in derivation to the other includes one
armature and one field coil. These circuits are of different
self-induction, and may be made so in various ways. For the sake
of clearness, an artificial resistance R is shown in one of these
circuits, and in the other a self-induction coil S. When an alternating
current is passed through this motor it divides between its two
energizing-circuits. The higher self-induction of one circuit produces a
greater retardation or lag in the current therein than in the other. The
difference of phase between the two currents effects the rotation or
shifting of the points of maximum magnetic effect that secures the
rotation of the armature. In certain respects this plan of including
both armature and field coils in circuit is a marked improvement. Such a
motor has a good torque at starting; yet it has also considerable
tendency to synchronism, owing to the fact that when properly
constructed the maximum magnetic effects in both armature and field
coincide--a condition which in the usual construction of these motors
with closed armature coils is not readily attained. The motor thus
constructed exhibits too, a better regulation of current from no load to
load, and there is less difference between the apparent and real energy
expended in running it. The true synchronous speed of this form of motor
is that of the generator when both are alike--that is to say, if the
number of the coils on the armature and on the field is _x_, the motor
will run normally at the same speed as a generator driving it if the
number of field magnets or poles of the same be also _x_.

[Illustration: FIGS. 45, 46 and 47.]

Fig. 43 shows a somewhat modified arrangement of circuits. There is in
this case but one armature coil E, the winding of which maintains
effects corresponding to the resultant poles produced by the two
field-circuits.

Fig. 44 represents a disposition in which both armature and field are
wound with two sets of coils, all in multiple arc to the line or main
circuit. The armature coils are wound to correspond with the field-coils
with respect to their self-induction. A modification of this plan is
shown in Fig. 45--that is to say, the two field coils and two armature
coils are in derivation to themselves and in series with one another.
The armature coils in this case, as in the previous figure, are wound
for different self-induction to correspond with the field coils.

Another modification is shown in Fig. 46. In this case only one
armature-coil, as D, is included in the line-circuit, while the other,
as C, is short-circuited.

In such a disposition as that shown in Fig. 43, or where only one
armature-coil is employed, the torque on the start is somewhat reduced,
while the tendency to synchronism is somewhat increased. In such a
disposition as shown in Fig. 46, the opposite conditions would exist. In
both instances, however, there is the advantage of dispensing with one
contact-ring.

[Illustration: FIG. 48.]

In Fig. 46 the two field-coils and the armature-coil D are in multiple
arc. In Fig. 47 this disposition is modified, coil D being shown in
series with the two field-coils.

Fig. 48 is an outline of the general form of motor in which this
invention is embodied. The circuit connections between the armature and
field coils are made, as indicated in the previous figures, through
brushes and rings, which are not shown.




CHAPTER XI.

ANOTHER METHOD OF TRANSFORMATION FROM A TORQUE TO A SYNCHRONIZING MOTOR.


In a preceding chapter we have described a method by which Mr. Tesla
accomplishes the change in his type of rotating field motor from a
torque to a synchronizing motor. As will be observed, the desired end is
there reached by a change in the circuit connections at the proper
moment. We will now proceed to describe another way of bringing about
the same result. The principle involved in this method is as follows:--

If an alternating current be passed through the field coils only of a
motor having two energizing circuits of different self-induction and the
armature coils be short-circuited, the motor will have a strong torque,
but little or no tendency to synchronism with the generator; but if the
same current which energizes the field be passed also through the
armature coils the tendency to remain in synchronism is very
considerably increased. This is due to the fact that the maximum
magnetic effects produced in the field and armature more nearly
coincide. On this principle Mr. Tesla constructs a motor having
independent field circuits of different self-induction, which are joined
in derivation to a source of alternating currents. The armature is wound
with one or more coils, which are connected with the field coils through
contact rings and brushes, and around the armature coils a shunt is
arranged with means for opening or closing the same. In starting this
motor the shunt is closed around the armature coils, which will
therefore be in closed circuit. When the current is directed through the
motor, it divides between the two circuits, (it is not necessary to
consider any case where there are more than two circuits used), which,
by reason of their different self-induction, secure a difference of
phase between the two currents in the two branches, that produces a
shifting or rotation of the poles. By the alternations of current, other
currents are induced in the closed--or short-circuited--armature coils
and the motor has a strong torque. When the desired speed is reached,
the shunt around the armature-coils is opened and the current directed
through both armature and field coils. Under these conditions the motor
has a strong tendency to synchronism.

[Illustration: FIGS. 49, 50 and 51.]

In Fig. 49, A and B designate the field coils of the motor. As the
circuits including these coils are of different self-induction, this is
represented by a resistance coil R in circuit with A, and a
self-induction coil S in circuit with B. The same result may of course
be secured by the winding of the coils. C is the armature circuit, the
terminals of which are rings _a b_. Brushes _c d_ bear on these rings
and connect with the line and field circuits. D is the shunt or short
circuit around the armature. E is the switch in the shunt.

It will be observed that in such a disposition as is illustrated in
Fig. 49, the field circuits A and B being of different self-induction,
there will always be a greater lag of the current in one than the other,
and that, generally, the armature phases will not correspond with
either, but with the resultant of both. It is therefore important to
observe the proper rule in winding the armature. For instance, if the
motor have eight poles--four in each circuit--there will be four
resultant poles, and hence the armature winding should be such as to
produce four poles, in order to constitute a true synchronizing motor.

[Illustration: FIG. 52.]

The diagram, Fig. 50, differs from the previous one only in respect to
the order of connections. In the present case the armature-coil, instead
of being in series with the field-coils, is in multiple arc therewith.
The armature-winding may be similar to that of the field--that is to
say, the armature may have two or more coils wound or adapted for
different self-induction and adapted, preferably, to produce the same
difference of phase as the field-coils. On starting the motor the shunt
is closed around both coils. This is shown in Fig. 51, in which the
armature coils are F G. To indicate their different electrical
character, there are shown in circuit with them, respectively, the
resistance R' and the self-induction coil S'. The two armature coils are
in series with the field-coils and the same disposition of the shunt or
short-circuit D is used. It is of advantage in the operation of motors
of this kind to construct or wind the armature in such manner that when
short-circuited on the start it will have a tendency to reach a higher
speed than that which synchronizes with the generator. For example, a
given motor having, say, eight poles should run, with the armature coil
short-circuited, at two thousand revolutions per minute to bring it up
to synchronism. It will generally happen, however, that this speed is
not reached, owing to the fact that the armature and field currents do
not properly correspond, so that when the current is passed through the
armature (the motor not being quite up to synchronism) there is a
liability that it will not "hold on," as it is termed. It is preferable,
therefore, to so wind or construct the motor that on the start, when the
armature coils are short-circuited, the motor will tend to reach a speed
higher than the synchronous--as for instance, double the latter. In such
case the difficulty above alluded to is not felt, for the motor will
always hold up to synchronism if the synchronous speed--in the case
supposed of two thousand revolutions--is reached or passed. This may be
accomplished in various ways; but for all practical purposes the
following will suffice: On the armature are wound two sets of coils. At
the start only one of these is short-circuited, thereby producing a
number of poles on the armature, which will tend to run the speed up
above the synchronous limit. When such limit is reached or passed, the
current is directed through the other coil, which, by increasing the
number of armature poles, tends to maintain synchronism.

[Illustration: FIG. 53.]

In Fig. 52, such a disposition is shown. The motor having, say, eight
poles contains two field-circuits A and B, of different self-induction.
The armature has two coils F and G. The former is closed upon itself,
the latter connected with the field and line through contact-rings _a
b_, brushes _c d_, and a switch E. On the start the coil F alone is
active and the motor tends to run at a speed above the synchronous; but
when the coil G is connected to the circuit the number of armature poles
is increased, while the motor is made a true synchronous motor. This
disposition has the advantage that the closed armature-circuit imparts
to the motor torque when the speed falls off, but at the same time the
conditions are such that the motor comes out of synchronism more
readily. To increase the tendency to synchronism, two circuits may be
used on the armature, one of which is short-circuited on the start and
both connected with the external circuit after the synchronous speed is
reached or passed. This disposition is shown in Fig. 53. There are three
contact-rings _a b e_ and three brushes _c d f_, which connect the
armature circuits with the external circuit. On starting, the switch H
is turned to complete the connection between one binding-post P and the
field-coils. This short-circuits one of the armature-coils, as G. The
other coil F is out of circuit and open. When the motor is up to speed,
the switch H is turned back, so that the connection from binding-post P
to the field coils is through the coil G, and switch K is closed,
thereby including coil F in multiple arc with the field coils. Both
armature coils are thus active.

From the above-described instances it is evident that many other
dispositions for carrying out the invention are possible.




CHAPTER XII.

"MAGNETIC LAG" MOTOR.


The following description deals with another form of motor, namely,
depending on "magnetic lag" or hysteresis, its peculiarity being that in
it the attractive effects or phases while lagging behind the phases of
current which produce them, are manifested simultaneously and not
successively. The phenomenon utilized thus at an early stage by Mr.
Tesla, was not generally believed in by scientific men, and Prof. Ayrton
was probably first to advocate it or to elucidate the reason of its
supposed existence.

Fig. 54 is a side view of the motor, in elevation. Fig. 55 is a
part-sectional view at right angles to Fig. 54. Fig. 56 is an end view
in elevation and part section of a modification, and Fig. 57 is a
similar view of another modification.

In Figs. 54 and 55, A designates a base or stand, and B B the
supporting-frame of the motor. Bolted to the supporting-frame are two
magnetic cores or pole-pieces C C', of iron or soft steel. These may be
subdivided or laminated, in which case hard iron or steel plates or bars
should be used, or they should be wound with closed coils. D is a
circular disc armature, built up of sections or plates of iron and
mounted in the frame between the pole-pieces C C', curved to conform to
the circular shape thereof. This disc may be wound with a number of
closed coils E. F F are the main energizing coils, supported by the
supporting-frame, so as to include within their magnetizing influence
both the pole-pieces C C' and the armature D. The pole-pieces C C'
project out beyond the coils F F on opposite sides, as indicated in the
drawings. If an alternating current be passed through the coils F F,
rotation of the armature will be produced, and this rotation is
explained by the following apparent action, or mode of operation: An
impulse of current in the coils F F establishes two polarities in the
motor. The protruding end of pole-piece C, for instance, will be of one
sign, and the corresponding end of pole-piece C' will be of the opposite
sign. The armature also exhibits two poles at right angles to the coils
F F, like poles to those in the pole-pieces being on the same side of
the coils. While the current is flowing there is no appreciable tendency
to rotation developed; but after each current impulse ceases or begins
to fall, the magnetism in the armature and in the ends of the
pole-pieces C C' lags or continues to manifest itself, which produces a
rotation of the armature by the repellent force between the more closely
approximating points of maximum magnetic effect. This effect is
continued by the reversal of current, the polarities of field and
armature being simply reversed. One or both of the elements--the
armature or field--may be wound with closed induced coils to intensify
this effect. Although in the illustrations but one of the fields is
shown, each element of the motor really constitutes a field, wound with
the closed coils, the currents being induced mainly in those
convolutions or coils which are parallel to the coils F F.

[Illustration: FIG. 54.]

[Illustration: FIG. 55.]

A modified form of this motor is shown in Fig. 56. In this form G is one
of two standards that support the bearings for the armature-shaft. H H
are uprights or sides of a frame, preferably magnetic, the ends C C' of
which are bent in the manner indicated, to conform to the shape of the
armature D and form field-magnet poles. The construction of the armature
may be the same as in the previous figure, or it may be simply a
magnetic disc or cylinder, as shown, and a coil or coils F F are
secured in position to surround both the armature and the poles C C'.
The armature is detachable from its shaft, the latter being passed
through the armature after it has been inserted in position. The
operation of this form of motor is the same in principle as that
previously described and needs no further explanation.

[Illustration: FIG. 56.]

[Illustration: FIG. 57.]

One of the most important features in alternating current motors is,
however, that they should be adapted to and capable of running
efficiently on the alternating circuits in present use, in which almost
without exception the generators yield a very high number of
alternations. Such a motor, of the type under consideration, Mr. Tesla
has designed by a development of the principle of the motor shown in
Fig. 56, making a multipolar motor, which is illustrated in Fig. 57. In
the construction of this motor he employs an annular magnetic frame J,
with inwardly-extending ribs or projections K, the ends of which all
bend or turn in one direction and are generally shaped to conform to the
curved surface of the armature. Coils F F are wound from one part K to
the one next adjacent, the ends or loops of each coil or group of wires
being carried over toward the shaft, so as to form U-shaped groups
of convolutions at each end of the armature. The pole-pieces C C', being
substantially concentric with the armature, form ledges, along which the
coils are laid and should project to some extent beyond the the coils,
as shown. The cylindrical or drum armature D is of the same construction
as in the other motors described, and is mounted to rotate within the
annular frame J and between the U-shaped ends or bends of the
coils F. The coils F are connected in multiple or in series with a
source of alternating currents, and are so wound that with a current or
current impulse of given direction they will make the alternate
pole-pieces C of one polarity and the other pole-pieces C' of the
opposite polarity. The principle of the operation of this motor is the
same as the other above described, for, considering any two pole-pieces
C C', a current impulse passing in the coil which bridges them or is
wound over both tends to establish polarities in their ends of opposite
sign and to set up in the armature core between them a polarity of the
same sign as that of the nearest pole-piece C. Upon the fall or
cessation of the current impulse that established these polarities the
magnetism which lags behind the current phase, and which continues to
manifest itself in the polar projections C C' and the armature, produces
by repulsion a rotation of the armature. The effect is continued by each
reversal of the current. What occurs in the case of one pair of
pole-pieces occurs simultaneously in all, so that the tendency to
rotation of the armature is measured by the sum of all the forces
exerted by the pole-pieces, as above described. In this motor also the
magnetic lag or effect is intensified by winding one or both cores with
closed induced coils. The armature core is shown as thus wound. When
closed coils are used, the cores should be laminated.

It is evident that a pulsatory as well as an alternating current might
be used to drive or operate the motors above described.

It will be understood that the degree of subdivision, the mass of the
iron in the cores, their size and the number of alternations in the
current employed to run the motor, must be taken into consideration in
order to properly construct this motor. In other words, in all such
motors the proper relations between the number of alternations and the
mass, size, or quality of the iron must be preserved in order to secure
the best results.




CHAPTER XIII.

METHOD OF OBTAINING DIFFERENCE OF PHASE BY MAGNETIC SHIELDING.


In that class of motors in which two or more sets of energizing magnets
are employed, and in which by artificial means a certain interval of
time is made to elapse between the respective maximum or minimum periods
or phases of their magnetic attraction or effect, the interval or
difference in phase between the two sets of magnets is limited in
extent. It is desirable, however, for the economical working of such
motors that the strength or attraction of one set of magnets should be
maximum, at the time when that of the other set is minimum, and
conversely; but these conditions have not heretofore been realized
except in cases where the two currents have been obtained from
independent sources in the same or different machines. Mr. Tesla has
therefore devised a motor embodying conditions that approach more nearly
the theoretical requirements of perfect working, or in other words, he
produces artificially a difference of magnetic phase by means of a
current from a single primary source sufficient in extent to meet the
requirements of practical and economical working. He employs a motor
with two sets of energizing or field magnets, each wound with coils
connected with a source of alternating or rapidly-varying currents, but
forming two separate paths or circuits. The magnets of one set are
protected to a certain extent from the energizing action of the current
by means of a magnetic shield or screen interposed between the magnet
and its energizing coil. This shield is properly adapted to the
conditions of particular cases, so as to shield or protect the main core
from magnetization until it has become itself saturated and no longer
capable of containing all the lines of force produced by the current. It
will be seen that by this means the energizing action begins in the
protected set of magnets a certain arbitrarily-determined period of time
later than in the other, and that by this means alone or in conjunction
with other means or devices heretofore employed a practical difference
of magnetic phase may readily be secured.

Fig. 58 is a view of a motor, partly in section, with a diagram
illustrating the invention. Fig. 59 is a similar view of a modification
of the same.

[Illustration: FIG. 58.]

[Illustration: FIG. 59.]

In Fig. 58, which exhibits the simplest form of the invention, A A is
the field-magnet of a motor, having, say, eight poles or
inwardly-projecting cores B and C. The cores B form one set of magnets
and are energized by coils D. The cores C, forming the other set are
energized by coils E, and the coils are connected, preferably, in series
with one another, in two derived or branched circuits, F G,
respectively, from a suitable source of current. Each coil E is
surrounded by a magnetic shield H, which is preferably composed of an
annealed, insulated, or oxidized iron wire wrapped or wound on the coils
in the manner indicated so as to form a closed magnetic circuit around
the coils and between the same and the magnetic cores C. Between the
pole pieces or cores B C is mounted the armature K, which, as is usual
in this type of machines, is wound with coils L closed upon themselves.
The operation resulting from this disposition is as follows: If a
current impulse be directed through the two circuits of the motor, it
will quickly energize the cores B, but not so the cores C, for the
reason that in passing through the coils E there is encountered the
influence of the closed magnetic circuits formed by the shields H. The
first effect is to retard effectively the current impulse in circuit G,
while at the same time the proportion of current which does pass does
not magnetize the cores C, which are shielded or screened by the
shields H. As the increasing electromotive force then urges more current
through the coils E, the iron wire H becomes magnetically saturated and
incapable of carrying all the lines of force, and hence ceases to
protect the cores C, which becomes magnetized, developing their maximum
effect after an interval of time subsequent to the similar manifestation
of strength in the other set of magnets, the extent of which is
arbitrarily determined by the thickness of the shield H, and other
well-understood conditions.

From the above it will be seen that the apparatus or device acts in two
ways. First, by retarding the current, and, second, by retarding the
magnetization of one set of the cores, from which its effectiveness will
readily appear.

Many modifications of the principle of this invention are possible. One
useful and efficient application of the invention is shown in Fig. 59.
In this figure a motor is shown similar in all respects to that above
described, except that the iron wire H, which is wrapped around the
coils E, is in this case connected in series with the coils D. The
iron-wire coils H, are connected and wound, so as to have little or no
self-induction, and being added to the resistance of the circuit F, the
action of the current in that circuit will be accelerated, while in the
other circuit G it will be retarded. The shield H may be made in many
forms, as will be understood, and used in different ways, as appears
from the foregoing description.

As a modification of his type of motor with "shielded" fields, Mr. Tesla
has constructed a motor with a field-magnet having two sets of poles or
inwardly-projecting cores and placed side by side, so as practically to
form two fields of force and alternately disposed--that is to say, with
the poles of one set or field opposite the spaces between the other. He
then connects the free ends of one set of poles by means of laminated
iron bands or bridge-pieces of considerably smaller cross-section than
the cores themselves, whereby the cores will all form parts of complete
magnetic circuits. When the coils on each set of magnets are connected
in multiple circuits or branches from a source of alternating currents,
electromotive forces are set up in or impressed upon each circuit
simultaneously; but the coils on the magnetically bridged or shunted
cores will have, by reason of the closed magnetic circuits, a high
self-induction, which retards the current, permitting at the beginning
of each impulse but little current to pass. On the other hand, no such
opposition being encountered in the other set of coils, the current
passes freely through them, magnetizing the poles on which they are
wound. As soon, however, as the laminated bridges become saturated and
incapable of carrying all the lines of force which the rising
electromotive force, and consequently increased current, produce, free
poles are developed at the ends of the cores, which, acting in
conjunction with the others, produce rotation of the armature.

The construction in detail by which this invention is illustrated is
shown in the accompanying drawings.

[Illustration: FIG. 60.]

[Illustration: FIG. 61.]

Fig. 60 is a view in side elevation of a motor embodying the principle.
Fig. 61 is a vertical cross-section of the motor. A is the frame of the
motor, which should be built up of sheets of iron punched out to the
desired shape and bolted together with insulation between the sheets.
When complete, the frame makes a field-magnet with inwardly projecting
pole-pieces B and C. To adapt them to the requirements of this
particular case these pole-pieces are out of line with one another,
those marked B surrounding one end of the armature and the others, as C,
the opposite end, and they are disposed alternately--that is to say, the
pole-pieces of one set occur in line with the spaces between those of
the other sets.

The armature D is of cylindrical form, and is also laminated in the
usual way and is wound longitudinally with coils closed upon themselves.
The pole-pieces C are connected or shunted by bridge-pieces E. These may
be made independently and attached to the pole-pieces, or they may be
parts of the forms or blanks stamped or punched out of sheet-iron. Their
size or mass is determined by various conditions, such as the strength
of the current to be employed, the mass or size of the cores to which
they are applied, and other familiar conditions.

Coils F surround the pole-pieces B, and other coils G are wound on the
pole-pieces C. These coils are connected in series in two circuits,
which are branches of a circuit from a generator of alternating
currents, and they may be so wound, or the respective circuits in which
they are included may be so arranged, that the circuit of coils G will
have, independently of the particular construction described, a higher
self-induction than the other circuit or branch.

The function of the shunts or bridges E is that they shall form with the
cores C a closed magnetic circuit for a current up to a predetermined
strength, so that when saturated by such current and unable to carry
more lines of force than such a current produces they will to no further
appreciable extent interfere with the development, by a stronger
current, of free magnetic poles at the ends of the cores C.

In such a motor the current is so retarded in the coils G, and the
manifestation of the free magnetism in the poles C is so delayed beyond
the period of maximum magnetic effect in poles B, that a strong torque
is produced and the motor operates with approximately the power
developed in a motor of this kind energized by independently generated
currents differing by a full quarter phase.




CHAPTER XIV.

TYPE OF TESLA SINGLE-PHASE MOTOR.


Up to this point, two principal types of Tesla motors have been
described: First, those containing two or more energizing circuits
through which are caused to pass alternating currents differing from one
another in phase to an extent sufficient to produce a continuous
progression or shifting of the poles or points of greatest magnetic
effect, in obedience to which the movable element of the motor is
maintained in rotation; second, those containing poles, or parts of
different magnetic susceptibility, which under the energizing influence
of the same current or two currents coinciding in phase will exhibit
differences in their magnetic periods or phases. In the first class of
motors the torque is due to the magnetism established in different
portions of the motor by currents from the same or from independent
sources, and exhibiting time differences in phase. In the second class
the torque results from the energizing effects of a current upon
different parts of the motor which differ in magnetic susceptibility--in
other words, parts which respond in the same relative degree to the
action of a current, not simultaneously, but after different intervals
of time.

In another Tesla motor, however, the torque, instead of being solely the
result of a time difference in the magnetic periods or phases of the
poles or attractive parts to whatever cause due, is produced by an
angular displacement of the parts which, though movable with respect to
one another, are magnetized simultaneously, or approximately so, by the
same currents. This principle of operation has been embodied practically
in a motor in which the necessary angular displacement between the
points of greatest magnetic attraction in the two elements of the
motor--the armature and field--is obtained by the direction of the
lamination of the magnetic cores of the elements.

Fig. 62 is a side view of such a motor with a portion of its armature
core exposed. Fig. 63 is an end or edge view of the same. Fig. 64 is a
central cross-section of the same, the armature being shown mainly in
elevation.

[Illustration: FIG. 62.]

[Illustration: FIG. 63.]

[Illustration: FIG. 64.]

Let A A designate two plates built up of thin sections or laminae of soft
iron insulated more or less from one another and held together by bolts
_a_ and secured to a base B. The inner faces of these plates contain
recesses or grooves in which a coil or coils D are secured obliquely to
the direction of the laminations. Within the coils D is a disc E,
preferably composed of a spirally-wound iron wire or ribbon or a series
of concentric rings and mounted on a shaft F, having bearings in the
plates A A. Such a device when acted upon by an alternating current is
capable of rotation and constitutes a motor, the operation of which may
be explained in the following manner: A current or current-impulse
traversing the coils D tends to magnetize the cores A A and E, all of
which are within the influence of the field of the coils. The poles thus
established would naturally lie in the same line at right angles to the
coils D, but in the plates A they are deflected by reason of the
direction of the laminations, and appear at or near the extremities of
these plates. In the disc, however, where these conditions are not
present, the poles or points of greatest attraction are on a line at
right angles to the plane of the coils; hence there will be a torque
established by this angular displacement of the poles or magnetic lines,
which starts the disc in rotation, the magnetic lines of the armature
and field tending toward a position of parallelism. This rotation is
continued and maintained by the reversals of the current in coils D D,
which change alternately the polarity of the field-cores A A. This
rotary tendency or effect will be greatly increased by winding the disc
with conductors G, closed upon themselves and having a radial direction,
whereby the magnetic intensity of the poles of the disc will be greatly
increased by the energizing effect of the currents induced in the coils
G by the alternating currents in coils D.

The cores of the disc and field may or may not be of different magnetic
susceptibility--that is to say, they may both be of the same kind of
iron, so as to be magnetized at approximately the same instant by the
coils D; or one may be of soft iron and the other of hard, in order that
a certain time may elapse between the periods of their magnetization. In
either case rotation will be produced; but unless the disc is provided
with the closed energizing coils it is desirable that the
above-described difference of magnetic susceptibility be utilized to
assist in its rotation.

The cores of the field and armature may be made in various ways, as will
be well understood, it being only requisite that the laminations in each
be in such direction as to secure the necessary angular displacement of
the points of greatest attraction. Moreover, since the disc may be
considered as made up of an infinite number of radial arms, it is
obvious that what is true of a disc holds for many other forms of
armature.




CHAPTER XV.

MOTORS WITH CIRCUITS OF DIFFERENT RESISTANCE.


As has been pointed out elsewhere, the lag or retardation of the phases
of an alternating current is directly proportional to the self-induction
and inversely proportional to the resistance of the circuit through
which the current flows. Hence, in order to secure the proper
differences of phase between the two motor-circuits, it is desirable to
make the self-induction in one much higher and the resistance much lower
than the self-induction and resistance, respectively, in the other. At
the same time the magnetic quantities of the two poles or sets of poles
which the two circuits produce should be approximately equal. These
requirements have led Mr. Tesla to the invention of a motor having the
following general characteristics: The coils which are included in that
energizing circuit which is to have the higher self-induction are made
of coarse wire, or a conductor of relatively low resistance, and with
the greatest possible length or number of turns. In the other set of
coils a comparatively few turns of finer wire are used, or a wire of
higher resistance. Furthermore, in order to approximate the magnetic
quantities of the poles excited by these coils, Mr. Tesla employs in the
self-induction circuit cores much longer than those in the other or
resistance circuit.

Fig. 65 is a part sectional view of the motor at right angles to the
shaft. Fig. 66 is a diagram of the field circuits.

In Fig. 66, let A represent the coils in one motor circuit, and B those
in the other. The circuit A is to have the higher self-induction. There
are, therefore, used a long length or a large number of turns of coarse
wire in forming the coils of this circuit. For the circuit B, a smaller
conductor is employed, or a conductor of a higher resistance than
copper, such as German silver or iron, and the coils are wound with
fewer turns. In applying these coils to a motor, Mr. Tesla builds up a
field-magnet of plates C, of iron and steel, secured together in the
usual manner by bolts D. Each plate is formed with four (more or less)
long cores E, around which is a space to receive the coil and an equal
number of short projections F to receive the coils of the
resistance-circuit. The plates are generally annular in shape, having an
open space in the centre for receiving the armature G, which Mr. Tesla
prefers to wind with closed coils. An alternating current divided
between the two circuits is retarded as to its phases in the circuit A
to a much greater extent than in the circuit B. By reason of the
relative sizes and disposition of the cores and coils the magnetic
effect of the poles E and F upon the armature closely approximate.

[Illustration: FIG. 65.]

[Illustration: FIG. 66.]

An important result secured by the construction shown here is that these
coils which are designed to have the higher self-induction are almost
completely surrounded by iron, and that the retardation is thus very
materially increased.




CHAPTER XVI.

MOTOR WITH EQUAL MAGNETIC ENERGIES IN FIELD AND ARMATURE.


Let it be assumed that the energy as represented in the magnetism in the
field of a given rotating field motor is ninety and that of the armature
ten. The sum of these quantities, which represents the total energy
expended in driving the motor, is one hundred; but, assuming that the
motor be so constructed that the energy in the field is represented by
fifty, and that in the armature by fifty, the sum is still one hundred;
but while in the first instance the product is nine hundred, in the
second it is two thousand five hundred, and as the energy developed is
in proportion to these products it is clear that those motors are the
most efficient--other things being equal--in which the magnetic energies
developed in the armature and field are equal. These results Mr. Tesla
obtains by using the same amount of copper or ampere turns in both
elements when the cores of both are equal, or approximately so, and the
same current energizes both; or in cases where the currents in one
element are induced to those of the other he uses in the induced coils
an excess of copper over that in the primary element or conductor.

[Illustration: FIG. 67.]

The conventional figure of a motor here introduced, Fig. 67, will give
an idea of the solution furnished by Mr. Tesla for the specific problem.
Referring to the drawing, A is the field-magnet, B the armature, C the
field coils, and D the armature-coils of the motor.

Generally speaking, if the mass of the cores of armature and field be
equal, the amount of copper or ampere turns of the energizing coils on
both should also be equal; but these conditions will be modified in
different forms of machine. It will be understood that these results are
most advantageous when existing under the conditions presented where the
motor is running with its normal load, a point to be well borne in
mind.




CHAPTER XVII.

MOTORS WITH COINCIDING MAXIMA OF MAGNETIC EFFECT IN ARMATURE AND FIELD.


In this form of motor, Mr. Tesla's object is to design and build
machines wherein the maxima of the magnetic effects of the armature and
field will more nearly coincide than in some of the types previously
under consideration. These types are: First, motors having two or more
energizing circuits of the same electrical character, and in the
operation of which the currents used differ primarily in phase; second,
motors with a plurality of energizing circuits of different electrical
character, in or by means of which the difference of phase is produced
artificially, and, third, motors with a plurality of energizing
circuits, the currents in one being induced from currents in another.
Considering the structural and operative conditions of any one of
them--as, for example, that first named--the armature which is mounted
to rotate in obedience to the co-operative influence or action of the
energizing circuits has coils wound upon it which are closed upon
themselves and in which currents are induced by the energizing-currents
with the object and result of energizing the armature-core; but under
any such conditions as must exist in these motors, it is obvious that a
certain time must elapse between the manifestations of an energizing
current impulse in the field coils, and the corresponding magnetic state
or phase in the armature established by the current induced thereby;
consequently a given magnetic influence or effect in the field which is
the direct result of a primary current impulse will have become more or
less weakened or lost before the corresponding effect in the armature
indirectly produced has reached its maximum. This is a condition
unfavorable to efficient working in certain cases--as, for instance,
when the progress of the resultant poles or points of maximum attraction
is very great, or when a very high number of alternations is
employed--for it is apparent that a stronger tendency to rotation will
be maintained if the maximum magnetic attractions or conditions in both
armature and field coincide, the energy developed by a motor being
measured by the product of the magnetic quantities of the armature and
field.

To secure this coincidence of maximum magnetic effects, Mr. Tesla has
devised various means, as explained below. Fig. 68 is a diagrammatic
illustration of a Tesla motor system in which the alternating currents
proceed from independent sources and differ primarily in phase.

[Illustration: FIG. 68.]

[Illustration: FIG. 69.]

A designates the field-magnet or magnetic frame of the motor; B B,
oppositely located pole-pieces adapted to receive the coils of one
energizing circuit; and C C, similar pole-pieces for the coils of the
other energizing circuit. These circuits are designated, respectively,
by D E, the conductor D'' forming a common return to the generator G.
Between these poles is mounted an armature--for example, a ring or
annular armature, wound with a series of coils F, forming a closed
circuit or circuits. The action or operation of a motor thus constructed
is now well understood. It will be observed, however, that the magnetism
of poles B, for example, established by a current impulse in the coils
thereon, precedes the magnetic effect set up in the armature by the
induced current in coils F. Consequently the mutual attraction between
the armature and field-poles is considerably reduced. The same
conditions will be found to exist if, instead of assuming the poles B or
C as acting independently, we regard the ideal resultant of both acting
together, which is the real condition. To remedy this, the motor field
is constructed with secondary poles B' C', which are situated between
the others. These pole-pieces are wound with coils D' E', the former in
derivation to the coils D, the latter to coils E. The main or primary
coils D and E are wound for a different self-induction from that of the
coils D' and E', the relations being so fixed that if the currents in D
and E differ, for example, by a quarter-phase, the currents in each
secondary coil, as D' E', will differ from those in its appropriate
primary D or E by, say, forty-five degrees, or one-eighth of a period.

Now, assuming that an impulse or alternation in circuit or branch E is
just beginning, while in the branch D it is just falling from maximum,
the conditions are those of a quarter-phase difference. The ideal
resultant of the attractive forces of the two sets of poles B C
therefore may be considered as progressing from poles B to poles C,
while the impulse in E is rising to maximum, and that in D is falling to
zero or minimum. The polarity set up in the armature, however, lags
behind the manifestations of field magnetism, and hence the maximum
points of attraction in armature and field, instead of coinciding, are
angularly displaced. This effect is counteracted by the supplemental
poles B' C'. The magnetic phases of these poles succeed those of poles B
C by the same, or nearly the same, period of time as elapses between the
effect of the poles B C and the corresponding induced effect in the
armature; hence the magnetic conditions of poles B' C' and of the
armature more nearly coincide and a better result is obtained. As poles
B' C' act in conjunction with the poles in the armature established by
poles B C, so in turn poles C B act similarly with the poles set up by
B' C', respectively. Under such conditions the retardation of the
magnetic effect of the armature and that of the secondary poles will
bring the maximum of the two more nearly into coincidence and a
correspondingly stronger torque or magnetic attraction secured.

In such a disposition as is shown in Fig. 68 it will be observed that
as the adjacent pole-pieces of either circuit are of like polarity they
will have a certain weakening effect upon one another. Mr. Tesla
therefore prefers to remove the secondary poles from the direct
influence of the others. This may be done by constructing a motor with
two independent sets of fields, and with either one or two armatures
electrically connected, or by using two armatures and one field. These
modifications are illustrated further on.

[Illustration: FIG. 70.]

[Illustration: FIG. 71.]

Fig. 69 is a diagrammatic illustration of a motor and system in which
the difference of phase is artificially produced. There are two coils D
D in one branch and two coils E E in another branch of the main circuit
from the generator G. These two circuits or branches are of different
self-induction, one, as D, being higher than the other. This is
graphically indicated by making coils D much larger than coils E. By
reason of the difference in the electrical character of the two
circuits, the phases of current in one are retarded to a greater extent
than the other. Let this difference be thirty degrees. A motor thus
constructed will rotate under the action of an alternating current; but
as happens in the case previously described the corresponding magnetic
effects of the armature and field do not coincide owing to the time that
elapses between a given magnetic effect in the armature and the
condition of the field that produces it. The secondary or supplemental
poles B' C' are therefore availed of. There being thirty degrees
difference of phase between the currents in coils D E, the magnetic
effect of poles B' C' should correspond to that produced by a current
differing from the current in coils D or E by fifteen degrees. This we
can attain by winding each supplemental pole B' C' with two coils H H'.
The coils H are included in a derived circuit having the same
self-induction as circuit D, and coils H' in a circuit having the same
self-induction as circuit E, so that if these circuits differ by thirty
degrees the magnetism of poles B' C' will correspond to that produced by
a current differing from that in either D or E by fifteen degrees. This
is true in all other cases. For example, if in Fig. 68 the coils D' E'
be replaced by the coils H H' included in the derived circuits, the
magnetism of the poles B' C' will correspond in effect or phase, if it
may be so termed, to that produced by a current differing from that in
either circuit D or E by forty-five degrees, or one-eighth of a period.

This invention as applied to a derived circuit motor is illustrated in
Figs. 70 and 71. The former is an end view of the motor with the
armature in section and a diagram of connections, and Fig. 71 a vertical
section through the field. These figures are also drawn to show one of
the dispositions of two fields that may be adopted in carrying out the
principle. The poles B B C C are in one field, the remaining poles in
the other. The former are wound with primary coils I J and secondary
coils I' J', the latter with coils K L. The primary coils I J are in
derived circuits, between which, by reason of their different
self-induction, there is a difference of phase, say, of thirty degrees.
The coils I' K are in circuit with one another, as also are coils J' L,
and there should be a difference of phase between the currents in coils
K and L and their corresponding primaries of, say, fifteen degrees. If
the poles B C are at right angles, the armature-coils should be
connected directly across, or a single armature core wound from end to
end may be used; but if the poles B C be in line there should be an
angular displacement of the armature coils, as will be well understood.

The operation will be understood from the foregoing. The maximum
magnetic condition of a pair of poles, as B' B', coincides closely with
the maximum effect in the armature, which lags behind the corresponding
condition in poles B B.




CHAPTER XVIII.

MOTOR BASED ON THE DIFFERENCE OF PHASE IN THE MAGNETIZATION OF THE INNER
AND OUTER PARTS OF AN IRON CORE.


It is well known that if a magnetic core, even if laminated or
subdivided, be wound with an insulated coil and a current of electricity
be directed through the coil, the magnetization of the entire core does
not immediately ensue, the magnetizing effect not being exhibited in all
parts simultaneously. This may be attributed to the fact that the action
of the current is to energize first those laminae or parts of the core
nearest the surface and adjacent to the exciting-coil, and from thence
the action progresses toward the interior. A certain interval of time
therefore elapses between the manifestation of magnetism in the external
and the internal sections or layers of the core. If the core be thin or
of small mass, this effect may be inappreciable; but in the case of a
thick core, or even of a comparatively thin one, if the number of
alternations or rate of change of the current strength be very great,
the time interval occurring between the manifestations of magnetism in
the interior of the core and in those parts adjacent to the coil is more
marked. In the construction of such apparatus as motors which are
designed to be run by alternating or equivalent currents--such as
pulsating or undulating currents generally--Mr. Tesla found it desirable
and even necessary to give due consideration to this phenomenon and to
make special provisions in order to obviate its consequences. With the
specific object of taking advantage of this action or effect, and to
render it more pronounced, he constructs a field magnet in which the
parts of the core or cores that exhibit at different intervals of time
the magnetic effect imparted to them by alternating or equivalent
currents in an energizing coil or coils, are so placed with relation to
a rotating armature as to exert thereon their attractive effect
successively in the order of their magnetization. By this means he
secures a result similar to that which he had previously attained in
other forms or types of motor in which by means of one or more
alternating currents he has produced the rotation or progression of the
magnetic poles.

This new mode of operation will now be described. Fig. 72 is a side
elevation of such motor. Fig. 73 is a side elevation of a more
practicable and efficient embodiment of the invention. Fig. 74 is a
central vertical section of the same in the plane of the axis of
rotation.

[Illustration: FIGS. 72 and 73.]

Referring to Fig. 72, let X represent a large iron core, which may be
composed of a number of sheets or laminae of soft iron or steel.
Surrounding this core is a coil Y, which is connected with a source E of
rapidly varying currents. Let us consider now the magnetic conditions
existing in this core at any point, as _b_, at or near the centre, and
any other point, as _a_, nearer the surface. When a current impulse is
started in the magnetizing coil Y, the section or part at _a_, being
close to the coil, is immediately energized, while the section or part
at _b_, which, to use a convenient expression, is "protected" by the
intervening sections or layers between _a_ and _b_, does not at once
exhibit its magnetism. However, as the magnetization of _a_ increases,
_b_ becomes also affected, reaching finally its maximum strength some
time later than _a_. Upon the weakening of the current the magnetization
of _a_ first diminishes, while _b_ still exhibits its maximum strength;
but the continued weakening of _a_ is attended by a subsequent weakening
of _b_. Assuming the current to be an alternating one, _a_ will now be
reversed, while _b_ still continues of the first imparted polarity. This
action continues the magnetic condition of _b_, following that of _a_ in
the manner above described. If an armature--for instance, a simple disc
F, mounted to rotate freely on an axis--be brought into proximity to the
core, a movement of rotation will be imparted to the disc, the direction
depending upon its position relatively to the core, the tendency being
to turn the portion of the disc nearest to the core from _a_ to _b_, as
indicated in Fig. 72.

[Illustration: FIG. 74.]

This action or principle of operation has been embodied in a practicable
form of motor, which is illustrated in Fig. 73. Let A in that figure
represent a circular frame of iron, from diametrically opposite points
of the interior of which the cores project. Each core is composed of
three main parts B, B and C, and they are similarly formed with a
straight portion or body _e_, around which the energizing coil is wound,
a curved arm or extension _c_, and an inwardly projecting pole or end
_d_. Each core is made up of two parts B B, with their polar extensions
reaching in one direction, and a part C between the other two, and with
its polar extension reaching in the opposite direction. In order to
lessen in the cores the circulation of currents induced therein, the
several sections are insulated from one another in the manner usually
followed in such cases. These cores are wound with coils D, which are
connected in the same circuit, either in parallel or series, and
supplied with an alternating or a pulsating current, preferably the
former, by a generator E, represented diagrammatically. Between the
cores or their polar extensions is mounted a cylindrical or similar
armature F, wound with magnetizing coils G, closed upon themselves.

The operation of this motor is as follows: When a current impulse or
alternation is directed through the coils D, the sections B B of the
cores, being on the surface and in close proximity to the coils, are
immediately energized. The sections C, on the other hand, are protected
from the magnetizing influence of the coil by the interposed layers of
iron B B. As the magnetism of B B increases, however, the sections C are
also energized; but they do not attain their maximum strength until a
certain time subsequent to the exhibition by the sections B B of their
maximum. Upon the weakening of the current the magnetic strength of B B
first diminishes, while the sections C have still their maximum
strength; but as B B continue to weaken the interior sections are
similarly weakened. B B may then begin to exhibit an opposite polarity,
which is followed later by a similar change on C, and this action
continues. B B and C may therefore be considered as separate
field-magnets, being extended so as to act on the armature in the most
efficient positions, and the effect is similar to that in the other
forms of Tesla motor--viz., a rotation or progression of the maximum
points of the field of force. Any armature--such, for instance, as a
disc--mounted in this field would rotate from the pole first to exhibit
its magnetism to that which exhibits it later.

It is evident that the principle here described may be carried out in
conjunction with other means for securing a more favorable or efficient
action of the motor. For example, the polar extensions of the sections C
may be wound or surrounded by closed coils. The effect of these coils
will be to still more effectively retard the magnetization of the polar
extensions of C.




CHAPTER XIX.

ANOTHER TYPE OF TESLA INDUCTION MOTOR.


It will have been gathered by all who are interested in the advance of
the electrical arts, and who follow carefully, step by step, the work of
pioneers, that Mr. Tesla has been foremost to utilize inductive effects
in permanently closed circuits, in the operation of alternating motors.
In this chapter one simple type of such a motor is described and
illustrated, which will serve as an exemplification of the principle.

Let it be assumed that an ordinary alternating current generator is
connected up in a circuit of practically no self-induction, such, for
example, as a circuit containing incandescent lamps only. On the
operation of the machine, alternating currents will be developed in the
circuit, and the phases of these currents will theoretically coincide
with the phases of the impressed electromotive force. Such currents may
be regarded and designated as the "unretarded currents."

It will be understood, of course, that in practice there is always more
or less self-induction in the circuit, which modifies to a corresponding
extent these conditions; but for convenience this may be disregarded in
the consideration of the principle of operation, since the same laws
apply. Assume next that a path of currents be formed across any two
points of the above circuit, consisting, for example, of the primary of
an induction device. The phases of the currents passing through the
primary, owing to the self-induction of the same, will not coincide with
the phases of the impressed electromotive force, but will lag behind,
such lag being directly proportional to the self-induction and inversely
proportional to the resistance of the said coil. The insertion of this
coil will also cause a lagging or retardation of the currents traversing
and delivered by the generator behind the impressed electromotive force,
such lag being the mean or resultant of the lag of the current through
the primary alone and of the "unretarded current" in the entire working
circuit. Next consider the conditions imposed by the association in
inductive relation with the primary coil, of a secondary coil. The
current generated in the secondary coil will react upon the primary
current, modifying the retardation of the same, according to the amount
of self-induction and resistance in the secondary circuit. If the
secondary circuit has but little self-induction--as, for instance, when
it contains incandescent lamps only--it will increase the actual
difference of phase between its own and the primary current, first, by
diminishing the lag between the primary current and the impressed
electromotive force, and, second, by its own lag or retardation behind
the impressed electromotive force. On the other hand, if the secondary
circuit have a high self-induction, its lag behind the current in the
primary is directly increased, while it will be still further increased
if the primary have a very low self-induction. The better results are
obtained when the primary has a low self-induction.

[Illustration: FIG. 75.]

[Illustration: FIG. 76.]

Fig. 75 is a diagram of a Tesla motor embodying this principle. Fig. 76
is a similar diagram of a modification of the same. In Fig. 75 let A
designate the field-magnet of a motor which, as in all these motors, is
built up of sections or plates. B C are polar projections upon which the
coils are wound. Upon one pair of these poles, as C, are wound primary
coils D, which are directly connected to the circuit of an alternating
current generator G. On the same poles are also wound secondary coils F,
either side by side or over or under the primary coils, and these are
connected with other coils E, which surround the poles B B. The
currents in both primary and secondary coils in such a motor will be
retarded or will lag behind the impressed electromotive force; but to
secure a proper difference in phase between the primary and secondary
currents themselves, Mr. Tesla increases the resistance of the circuit
of the secondary and reduces as much as practicable its self-induction.
This is done by using for the secondary circuit, particularly in the
coils E, wire of comparatively small diameter and having but few turns
around the cores; or by using some conductor of higher specific
resistance, such as German silver; or by introducing at some point in
the secondary circuit an artificial resistance R. Thus the
self-induction of the secondary is kept down and its resistance
increased, with the result of decreasing the lag between the impressed
electro-motive force and the current in the primary coils and increasing
the difference of phase between the primary and secondary currents.

In the disposition shown in Fig. 76, the lag in the secondary is
increased by increasing the self-induction of that circuit, while the
increasing tendency of the primary to lag is counteracted by inserting
therein a dead resistance. The primary coils D in this case have a low
self-induction and high resistance, while the coils E F, included in the
secondary circuit, have a high self-induction and low resistance. This
may be done by the proper winding of the coils; or in the circuit
including the secondary coils E F, we may introduce a self-induction
coil S, while in the primary circuit from the generator G and including
coils D, there may be inserted a dead resistance R. By this means the
difference of phase between the primary and secondary is increased. It
is evident that both means of increasing the difference of
phase--namely, by the special winding as well as by the supplemental or
external inductive and dead resistance--may be employed conjointly.

In the operation of this motor the current impulses in the primary coils
induce currents in the secondary coils, and by the conjoint action of
the two the points of greatest magnetic attraction are shifted or
rotated.

In practice it is found desirable to wind the armature with closed coils
in which currents are induced by the action thereon of the primaries.




CHAPTER XX.

COMBINATIONS OF SYNCHRONIZING MOTOR AND TORQUE MOTOR.


In the preceding descriptions relative to synchronizing motors and
methods of operating them, reference has been made to the plan adopted
by Mr. Tesla, which consists broadly in winding or arranging the motor
in such manner that by means of suitable switches it could be started as
a multiple-circuit motor, or one operating by a progression of its
magnetic poles, and then, when up to speed, or nearly so, converted into
an ordinary synchronizing motor, or one in which the magnetic poles were
simply alternated. In some cases, as when a large motor is used and when
the number of alternations is very high, there is more or less
difficulty in bringing the motor to speed as a double or
multiple-circuit motor, for the plan of construction which renders the
motor best adapted to run as a synchronizing motor impairs its
efficiency as a torque or double-circuit motor under the assumed
conditions on the start. This will be readily understood, for in a large
synchronizing motor the length of the magnetic circuit of the polar
projections, and their mass, are so great that apparently considerable
time is required for magnetization and demagnetization. Hence with a
current of a very high number of alternations the motor may not respond
properly. To avoid this objection and to start up a synchronizing motor
in which these conditions obtain, Mr. Tesla has combined two motors, one
a synchronizing motor, the other a multiple-circuit or torque motor, and
by the latter he brings the first-named up to speed, and then either
throws the whole current into the synchronizing motor or operates
jointly both of the motors.

This invention involves several novel and useful features. It will be
observed, in the first place, that both motors are run, without
commutators of any kind, and, secondly, that the speed of the torque
motor may be higher than that of the synchronizing motor, as will be the
case when it contains a fewer number of poles or sets of poles, so that
the motor will be more readily and easily brought up to speed. Thirdly,
the synchronizing motor may be constructed so as to have a much more
pronounced tendency to synchronism without lessening the facility with
which it is started.

Fig. 77 is a part sectional view of the two motors; Fig. 78 an end view
of the synchronizing motor; Fig. 79 an end view and part section of the
torque or double-circuit motor; Fig. 80 a diagram of the circuit
connections employed; and Figs. 81, 82, 83, 84 and 85 are diagrams of
modified dispositions of the two motors.

[Illustration: FIG. 77.]

Inasmuch as neither motor is doing any work while the current is acting
upon the other, the two armatures are rigidly connected, both being
mounted upon the same shaft A, the field-magnets B of the synchronizing
and C of the torque motor being secured to the same base D. The
preferably larger synchronizing motor has polar projections on its
armature, which rotate in very close proximity to the poles of the
field, and in other respects it conforms to the conditions that are
necessary to secure synchronous action. The pole-pieces of the armature
are, however, wound with closed coils E, as this obviates the employment
of sliding contacts. The smaller or torque motor, on the other hand,
has, preferably, a cylindrical armature F, without polar projections and
wound with closed coils G. The field-coils of the torque motor are
connected up in two series H and I, and the alternating current from the
generator is directed through or divided between these two circuits in
any manner to produce a progression of the poles or points of maximum
magnetic effect. This result is secured by connecting the two
motor-circuits in derivation with the circuit from the generator,
inserting in one motor circuit a dead resistance and in the other a
self-induction coil, by which means a difference in phase between the
two divisions of the current is secured. If both motors have the same
number of field poles, the torque motor for a given number of
alternations will tend to run at double the speed of the other, for,
assuming the connections to be such as to give the best results, its
poles are divided into two series and the number of poles is virtually
reduced one-half, which being acted upon by the same number of
alternations tend to rotate the armature at twice the speed. By this
means the main armature is more easily brought to or above the required
speed. When the speed necessary for synchronism is imparted to the main
motor, the current is shifted from the torque motor into the other.

[Illustration: FIG. 78.]

[Illustration: FIG. 79.]

A convenient arrangement for carrying out this invention is shown in
Fig. 80, in which J J are the field coils of the synchronizing, and H I
the field coils of the torque motor. L L' are the conductors of the main
line. One end of, say, coils H is connected to wire L through a
self-induction coil M. One end of the other set of coils I is connected
to the same wire through a dead resistance N. The opposite ends of these
two circuits are connected to the contact _m_ of a switch, the handle or
lever of which is in connection with the line-wire L'. One end of the
field circuit of the synchronizing motor is connected to the wire L. The
other terminates in the switch-contact _n_. From the diagram it will be
readily seen that if the lever P be turned upon contact _m_, the torque
motor will start by reason of the difference of phase between the
currents in its two energizing circuits. Then when the desired speed is
attained, if the lever P be shifted upon contact _n_ the entire current
will pass through the field coils of the synchronizing motor and the
other will be doing no work.

The torque motor may be constructed and operated in various ways, many
of which have already been touched upon. It is not necessary that one
motor be cut out of circuit while the other is in, for both may be acted
upon by current at the same time, and Mr. Tesla has devised various
dispositions or arrangements of the two motors for accomplishing this.
Some of these arrangements are illustrated in Figs. 81 to 85.

[Illustration: FIG. 80.]

Referring to Fig. 81, let T designate the torque or multiple circuit
motor and S the synchronizing motor, L L' being the line-wires from a
source of alternating current. The two circuits of the torque motor of
different degrees of self-induction, and designated by N M, are
connected in derivation to the wire L. They are then joined and
connected to the energizing circuit of the synchronizing motor, the
opposite terminal of which is connected to wire L'. The two motors are
thus in series. To start them Mr. Tesla short-circuits the synchronizing
motor by a switch P', throwing the whole current through the torque
motor. Then when the desired speed is reached the switch P' is opened,
so that the current passes through both motors. In such an arrangement
as this it is obviously desirable for economical and other reasons that
a proper relation between the speeds of the two motors should be
observed.

In Fig. 82 another disposition is illustrated. S is the synchronizing
motor and T the torque motor, the circuits of both being in parallel. W
is a circuit also in derivation to the motor circuits and containing a
switch P''. S' is a switch in the synchronizing motor circuit. On the
start the switch S' is opened, cutting out the motor S. Then P'' is
opened, throwing the entire current through the motor T, giving it a
very strong torque. When the desired speed is reached, switch S' is
closed and the current divides between both motors. By means of switch
P'' both motors may be cut out.

[Illustration: FIGS. 81, 82, 83, 84 and 85.]

In Fig. 83 the arrangement is substantially the same, except that a
switch T' is placed in the circuit which includes the two circuits of
the torque motor. Fig. 84 shows the two motors in series, with a shunt
around both containing a switch S T. There is also a shunt around the
synchronizing motor S, with a switch P'. In Fig. 85 the same disposition
is shown; but each motor is provided with a shunt, in which are switches
P' and T'', as shown.




CHAPTER XXI.

MOTOR WITH A CONDENSER IN THE ARMATURE CIRCUIT.


We now come to a new class of motors in which resort is had to
condensers for the purpose of developing the required difference of
phase and neutralizing the effects of self-induction. Mr. Tesla early
began to apply the condenser to alternating apparatus, in just how many
ways can only be learned from a perusal of other portions of this
volume, especially those dealing with his high frequency work.

Certain laws govern the action or effects produced by a condenser when
connected to an electric circuit through which an alternating or in
general an undulating current is made to pass. Some of the most
important of such effects are as follows: First, if the terminals or
plates of a condenser be connected with two points of a circuit, the
potentials of which are made to rise and fall in rapid succession, the
condenser allows the passage, or more strictly speaking, the
transference of a current, although its plates or armatures may be so
carefully insulated as to prevent almost completely the passage of a
current of unvarying strength or direction and of moderate electromotive
force. Second, if a circuit, the terminals of which are connected with
the plates of the condenser, possess a certain self-induction, the
condenser will overcome or counteract to a greater or less degree,
dependent upon well-understood conditions, the effects of such
self-induction. Third, if two points of a closed or complete circuit
through which a rapidly rising and falling current flows be shunted or
bridged by a condenser, a variation in the strength of the currents in
the branches and also a difference of phase of the currents therein is
produced. These effects Mr. Tesla has utilized and applied in a variety
of ways in the construction and operation of his motors, such as by
producing a difference in phase in the two energizing circuits of an
alternating current motor by connecting the two circuits in derivation
and connecting up a condenser in series in one of the circuits. A
further development, however, possesses certain novel features of
practical value and involves a knowledge of facts less generally
understood. It comprises the use of a condenser or condensers in
connection with the induced or armature circuit of a motor and certain
details of the construction of such motors. In an alternating current
motor of the type particularly referred to above, or in any other which
has an armature coil or circuit closed upon itself, the latter
represents not only an inductive resistance, but one which is
periodically varying in value, both of which facts complicate and
render difficult the attainment of the conditions best suited to the
most efficient working conditions; in other words, they require, first,
that for a given inductive effect upon the armature there should be the
greatest possible current through the armature or induced coils, and,
second, that there should always exist between the currents in the
energizing and the induced circuits a given relation of phase. Hence
whatever tends to decrease the self-induction and increase the current
in the induced circuits will, other things being equal, increase the
output and efficiency of the motor, and the same will be true of causes
that operate to maintain the mutual attractive effect between the field
magnets and armature at its maximum. Mr. Tesla secures these results by
connecting with the induced circuit or circuits a condenser, in the
manner described below, and he also, with this purpose in view,
constructs the motor in a special manner.

[Illustration: FIG. 86.]

[Illustration: FIG. 88.]

[Illustration: FIG. 89.]

[Illustration: FIG. 87.]

[Illustration: FIG. 90.]

Referring to the drawings, Fig. 86, is a view, mainly diagrammatic, of
an alternating current motor, in which the present principle is applied.
Fig. 87 is a central section, in line with the shaft, of a special form
of armature core. Fig. 88 is a similar section of a modification of the
same. Fig. 89 is one of the sections of the core detached. Fig. 90 is a
diagram showing a modified disposition of the armature or induced
circuits.

The general plan of the invention is illustrated in Fig. 86. A A in this
figure represent the the frame and field magnets of an alternating
current motor, the poles or projections of which are wound with coils B
and C, forming independent energizing circuits connected either to the
same or to independent sources of alternating currents, so that the
currents flowing through the circuits, respectively, will have a
difference of phase. Within the influence of this field is an armature
core D, wound with coils E. In motors of this description heretofore
these coils have been closed upon themselves, or connected in a closed
series; but in the present case each coil or the connected series of
coils terminates in the opposite plates of a condenser F. For this
purpose the ends of the series of coils are brought out through the
shaft to collecting rings G, which are connected to the condenser by
contact brushes H and suitable conductors, the condenser being
independent of the machine. The armature coils are wound or connected in
such manner that adjacent coils produce opposite poles.

The action of this motor and the effect of the plan followed in its
construction are as follows: The motor being started in operation and
the coils of the field magnets being traversed by alternating currents,
currents are induced in the armature coils by one set of field coils, as
B, and the poles thus established are acted upon by the other set, as C.
The armature coils, however, have necessarily a high self-induction,
which opposes the flow of the currents thus set up. The condenser F not
only permits the passage or transference of these currents, but also
counteracts the effects of self-induction, and by a proper adjustment of
the capacity of the condenser, the self-induction of the coils, and the
periods of the currents, the condenser may be made to overcome entirely
the effect of self-induction.

It is preferable on account of the undesirability of using sliding
contacts of any kind, to associate the condenser with the armature
directly, or make it a part of the armature. In some cases Mr. Tesla
builds up the armature of annular plates K K, held by bolts L between
heads M, which are secured to the driving shaft, and in the hollow space
thus formed he places a condenser F, generally by winding the two
insulated plates spirally around the shaft. In other cases he utilizes
the plates of the core itself as the plates of the condenser. For
example, in Figs. 88 and 89, N is the driving shaft, M M are the heads
of the armature-core, and K K' the iron plates of which the core is
built up. These plates are insulated from the shaft and from one
another, and are held together by rods or bolts L. The bolts pass
through a large hole in one plate and a small hole in the one next
adjacent, and so on, connecting electrically all of plates K, as one
armature of a condenser, and all of plates K' as the other.

To either of the condensers above described the armature coils may be
connected, as explained by reference to Fig. 86.

In motors in which the armature coils are closed upon themselves--as,
for example, in any form of alternating current motor in which one
armature coil or set of coils is in the position of maximum induction
with respect to the field coils or poles, while the other is in the
position of minimum induction--the coils are best connected in one
series, and two points of the circuit thus formed are bridged by a
condenser. This is illustrated in Fig. 90, in which E represents one set
of armature coils and E' the other. Their points of union are joined
through a condenser F. It will be observed that in this disposition the
self-induction of the two branches E and E' varies with their position
relatively to the field magnet, and that each branch is alternately the
predominating source of the induced current. Hence the effect of the
condenser F is twofold. First, it increases the current in each of the
branches alternately, and, secondly, it alters the phase of the currents
in the branches, this being the well-known effect which results from
such a disposition of a condenser with a circuit, as above described.
This effect is favorable to the proper working of the motor, because it
increases the flow of current in the armature circuits due to a given
inductive effect, and also because it brings more nearly into
coincidence the maximum magnetic effects of the coacting field and
armature poles.

It will be understood, of course, that the causes that contribute to the
efficiency of condensers when applied to such uses as the above must be
given due consideration in determining the practicability and efficiency
of the motors. Chief among these is, as is well known, the periodicity
of the current, and hence the improvements described are more
particularly adapted to systems in which a very high rate of alternation
or change is maintained.

Although this invention has been illustrated in connection with a
special form of motor, it will be understood that it is equally
applicable to any other alternating current motor in which there is a
closed armature coil wherein the currents are induced by the action of
the field, and the feature of utilizing the plates or sections of a
magnetic core for forming the condenser is applicable, generally, to
other kinds of alternating current apparatus.




CHAPTER XXII.

MOTOR WITH CONDENSER IN ONE OF THE FIELD CIRCUITS.


If the field or energizing circuits of a rotary phase motor be both
derived from the same source of alternating currents and a condenser of
proper capacity be included in one of the same, approximately, the
desired difference of phase may be obtained between the currents flowing
directly from the source and those flowing through the condenser; but
the great size and expense of condensers for this purpose that would
meet the requirements of the ordinary systems of comparatively low
potential are particularly prohibitory to their employment.

Another, now well-known, method or plan of securing a difference of
phase between the energizing currents of motors of this kind is to
induce by the currents in one circuit those in the other circuit or
circuits; but as no means had been proposed that would secure in this
way between the phases of the primary or inducing and the secondary or
induced currents that difference--theoretically ninety degrees--that is
best adapted for practical and economical working, Mr. Tesla devised a
means which renders practicable both the above described plans or
methods, and by which he is enabled to obtain an economical and
efficient alternating current motor. His invention consists in placing a
condenser in the secondary or induced circuit of the motor above
described and raising the potential of the secondary currents to such a
degree that the capacity of the condenser, which is in part dependent on
the potential, need be quite small. The value of this condenser is
determined in a well-understood manner with reference to the
self-induction and other conditions of the circuit, so as to cause the
currents which pass through it to differ from the primary currents by a
quarter phase.

Fig. 91 illustrates the invention as embodied in a motor in which the
inductive relation of the primary and secondary circuits is secured by
winding them inside the motor partly upon the same cores; but the
invention applies, generally, to other forms of motor in which one of
the energizing currents is induced in any way from the other.

Let A B represent the poles of an alternating current motor, of which C
is the armature wound with coils D, closed upon themselves, as is now
the general practice in motors of this kind. The poles A, which
alternate with poles B, are wound with coils of ordinary or coarse wire
E in such direction as to make them of alternate north and south
polarity, as indicated in the diagram by the characters N S. Over these
coils, or in other inductive relation to the same, are wound long
fine-wire coils F F, and in the same direction throughout as the coils
E. These coils are secondaries, in which currents of very high potential
are induced. All the coils E in one series are connected, and all the
secondaries F in another.

[Illustration: FIG. 91.]

On the intermediate poles B are wound fine-wire energizing coils G,
which are connected in series with one another, and also with the series
of secondary coils F, the direction of winding being such that a
current-impulse induced from the primary coils E imparts the same
magnetism to the poles B as that produced in poles A by the primary
impulse. This condition is indicated by the characters N' S'.

In the circuit formed by the two sets of coils F and G is introduced a
condenser H; otherwise this circuit is closed upon itself, while the
free ends of the circuit of coils E are connected to a source of
alternating currents. As the condenser capacity which is needed in any
particular motor of this kind is dependent upon the rate of alternation
or the potential, or both, its size or cost, as before explained, may be
brought within economical limits for use with the ordinary circuits if
the potential of the secondary circuit in the motor be sufficiently
high. By giving to the condenser proper values, any desired difference
of phase between the primary and secondary energizing circuits may be
obtained.




CHAPTER XXIII.

TESLA POLYPHASE TRANSFORMER.


Applying the polyphase principle to the construction of transformers as
well to the motors already noticed, Mr. Tesla has invented some very
interesting forms, which he considers free from the defects of earlier
and, at present, more familiar forms. In these transformers he provides
a series of inducing coils and corresponding induced coils, which are
generally wound upon a core closed upon itself, usually a ring of
laminated iron.

The two sets of coils are wound side by side or superposed or otherwise
placed in well-known ways to bring them into the most effective
relations to one another and to the core. The inducing or primary coils
wound on the core are divided into pairs or sets by the proper
electrical connections, so that while the coils of one pair or set
co-operate in fixing the magnetic poles of the core at two given
diametrically opposite points, the coils of the other pair or
set--assuming, for sake of illustration, that there are but two--tend to
fix the poles ninety degrees from such points. With this induction
device is used an alternating current generator with coils or sets of
coils to correspond with those of the converter, and the corresponding
coils of the generator and converter are then connected up in
independent circuits. It results from this that the different electrical
phases in the generator are attended by corresponding magnetic changes
in the converter; or, in other words, that as the generator coils
revolve, the points of greatest magnetic intensity in the converter will
be progressively shifted or whirled around.

Fig. 92 is a diagrammatic illustration of the converter and the
electrical connections of the same. Fig. 93 is a horizontal central
cross-section of Fig. 92. Fig. 94 is a diagram of the circuits of the
entire system, the generator being shown in section.

Mr. Tesla uses a core, A, which is closed upon itself--that is to say,
of an annular cylindrical or equivalent form--and as the efficiency of
the apparatus is largely increased by the subdivision of this core, he
makes it of thin strips, plates, or wires of soft iron electrically
insulated as far as practicable. Upon this core are wound, say, four
coils, B B B' B', used as primary coils, and for which long lengths of
comparatively fine wire are employed. Over these coils are then wound
shorter coils of coarser wire, C C C' C', to constitute the induced or
secondary coils. The construction of this or any equivalent form of
converter may be carried further, as above pointed out, by inclosing
these coils with iron--as, for example, by winding over the coils layers
of insulated iron wire.

[Illustration: FIGS. 92 and 93.]

[Illustration: FIG. 94.]

The device is provided with suitable binding posts, to which the ends of
the coils are led. The diametrically opposite coils B B and B' B' are
connected, respectively, in series, and the four terminals are connected
to the binding posts. The induced coils are connected together in any
desired manner. For example, as shown in Fig. 94, C C may be connected
in multiple arc when a quantity current is desired--as for running a
group of incandescent lamps--while C' C' may be independently connected
in series in a circuit including arc lamps or the like. The generator in
this system will be adapted to the converter in the manner illustrated.
For example, in the present case there are employed a pair of ordinary
permanent or electro-magnets, E E, between which is mounted a
cylindrical armature on a shaft, F, and wound with two coils, G G'. The
terminals of these coils are connected, respectively, to four insulated
contact or collecting rings, H H H' H', and the four line circuit wires
L connect the brushes K, bearing on these rings, to the converter in the
order shown. Noting the results of this combination, it will be observed
that at a given point of time the coil G is in its neutral position and
is generating little or no current, while the other coil, G', is in a
position where it exerts its maximum effect. Assuming coil G to be
connected in circuit with coils B B of the converter, and coil G' with
coils B' B', it is evident that the poles of the ring A will be
determined by coils B' B' alone; but as the armature of the generator
revolves, coil G develops more current and coil G' less, until G reaches
its maximum and G' its neutral position. The obvious result will be to
shift the poles of the ring A through one-quarter of its periphery. The
movement of the coils through the next quarter of a turn--during which
coil G' enters a field of opposite polarity and generates a current of
opposite direction and increasing strength, while coil G, in passing
from its maximum to its neutral position generates a current of
decreasing strength and same direction as before--causes a further
shifting of the poles through the second quarter of the ring. The second
half-revolution will obviously be a repetition of the same action. By
the shifting of the poles of the ring A, a powerful dynamic inductive
effect on the coils C C' is produced. Besides the currents generated in
the secondary coils by dynamo-magnetic induction, other currents will be
set up in the same coils in consequence of many variations in the
intensity of the poles in the ring A. This should be avoided by
maintaining the intensity of the poles constant, to accomplish which
care should be taken in designing and proportioning the generator and in
distributing the coils in the ring A, and balancing their effect. When
this is done, the currents are produced by dynamo-magnetic induction
only, the same result being obtained as though the poles were shifted by
a commutator with an infinite number of segments.

The modifications which are applicable to other forms of converter are
in many respects applicable to this, such as those pertaining more
particularly to the form of the core, the relative lengths and
resistances of the primary and secondary coils, and the arrangements for
running or operating the same.




CHAPTER XXIV.

A CONSTANT CURRENT TRANSFORMER WITH MAGNETIC SHIELD BETWEEN COILS OF
PRIMARY AND SECONDARY.


Mr. Tesla has applied his principle of magnetic shielding of parts to
the construction also of transformers, the shield being interposed
between the primary and secondary coils. In transformers of the ordinary
type it will be found that the wave of electromotive force of the
secondary very nearly coincides with that of the primary, being,
however, in opposite sign. At the same time the currents, both primary
and secondary, lag behind their respective electromotive forces; but as
this lag is practically or nearly the same in the case of each it
follows that the maximum and minimum of the primary and secondary
currents will nearly coincide, but differ in sign or direction, provided
the secondary be not loaded or if it contain devices having the property
of self-induction. On the other hand, the lag of the primary behind the
impressed electromotive force may be diminished by loading the secondary
with a non-inductive or dead resistance--such as incandescent
lamps--whereby the time interval between the maximum or minimum periods
of the primary and secondary currents is increased. This time interval,
however, is limited, and the results obtained by phase difference in the
operation of such devices as the Tesla alternating current motors can
only be approximately realized by such means of producing or securing
this difference, as above indicated, for it is desirable in such cases
that there should exist between the primary and secondary currents, or
those which, however produced, pass through the two circuits of the
motor, a difference of phase of ninety degrees; or, in other words, the
current in one circuit should be a maximum when that in the other
circuit is a minimum. To attain to this condition more perfectly, an
increased retardation of the secondary current is secured in the
following manner: Instead of bringing the primary and secondary coils or
circuits of a transformer into the closest possible relations, as has
hitherto been done, Mr. Tesla protects in a measure the secondary from
the inductive action or effect of the primary by surrounding either the
primary or the secondary with a comparatively thin magnetic shield or
screen. Under these modified conditions, as long as the primary current
has a small value, the shield protects the secondary; but as soon as the
primary current has reached a certain strength, which is arbitrarily
determined, the protecting magnetic shield becomes saturated and the
inductive action upon the secondary begins. It results, therefore, that
the secondary current begins to flow at a certain fraction of a period
later than it would without the interposed shield, and since this
retardation may be obtained without necessarily retarding the primary
current also, an additional lag is secured, and the time interval
between the maximum or minimum periods of the primary and secondary
currents is increased. Such a transformer may, by properly proportioning
its several elements and determining the proper relations between the
primary and secondary windings, the thickness of the magnetic shield,
and other conditions, be constructed to yield a constant current at all
loads.

[Illustration: FIG. 95.]

Fig. 95 is a cross-section of a transformer embodying this improvement.
Fig. 96 is a similar view of a modified form of transformer, showing
diagrammatically the manner of using the same.

A A is the main core of the transformer, composed of a ring of soft
annealed and insulated or oxidized iron wire. Upon this core is wound
the secondary circuit or coil B B. This latter is then covered with a
layer or layers of annealed and insulated iron wires C C, wound in a
direction at right angles to the secondary coil. Over the whole is then
wound the primary coil or wire D D. From the nature of this construction
it will be obvious that as long as the shield formed by the wires C is
below magnetic saturation the secondary coil or circuit is effectually
protected or shielded from the inductive influence of the primary,
although on open circuit it may exhibit some electromotive force. When
the strength of the primary reaches a certain value, the shield C,
becoming saturated, ceases to protect the secondary from inductive
action, and current is in consequence developed therein. For similar
reasons, when the primary current weakens, the weakening of the
secondary is retarded to the same or approximately the same extent.

[Illustration: FIG. 96.]

The specific construction of the transformer is largely immaterial. In
Fig. 96, for example, the core A is built up of thin insulated iron
plates or discs. The primary circuit D is wound next the core A. Over
this is applied the shield C, which in this case is made up of thin
strips or plates of iron properly insulated and surrounding the primary,
forming a closed magnetic circuit. The secondary B is wound over the
shield C. In Fig. 96, also, E is a source of alternating or rapidly
changing currents. The primary of the transformer is connected with the
circuit of the generator. F is a two-circuit alternating current motor,
one of the circuits being connected with the main circuit from the
source E, and the other being supplied with currents from the secondary
of the transformer.




PART II.

THE TESLA EFFECTS WITH HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS.




CHAPTER XXV.

INTRODUCTION.--THE SCOPE OF THE TESLA LECTURES.


Before proceeding to study the three Tesla lectures here presented, the
reader may find it of some assistance to have his attention directed to
the main points of interest and significance therein. The first of these
lectures was delivered in New York, at Columbia College, before the
American Institute of Electrical Engineers, May 20, 1891. The urgent
desire expressed immediately from all parts of Europe for an opportunity
to witness the brilliant and unusual experiments with which the lecture
was accompanied, induced Mr. Tesla to go to England early in 1892, when
he appeared before the Institution of Electrical Engineers, and a day
later, by special request, before the Royal Institution. His reception
was of the most enthusiastic and flattering nature on both occasions. He
then went, by invitation, to France, and repeated his novel
demonstrations before the Societe Internationale des Electriciens, and
the Societe Francaise de Physique. Mr. Tesla returned to America in the
fall of 1892, and in February, 1893, delivered his third lecture before
the Franklin Institute of Philadelphia, in fulfilment of a long standing
promise to Prof. Houston. The following week, at the request of
President James I. Ayer, of the National Electric Light Association, the
same lecture was re-delivered in St. Louis. It had been intended to
limit the invitations to members, but the appeals from residents in the
city were so numerous and pressing that it became necessary to secure a
very large hall. Hence it came about that the lecture was listened to by
an audience of over 5,000 people, and was in some parts of a more
popular nature than either of its predecessors. Despite this concession
to the need of the hour and occasion, Mr. Tesla did not hesitate to show
many new and brilliant experiments, and to advance the frontier of
discovery far beyond any point he had theretofore marked publicly.

We may now proceed to a running review of the lectures themselves. The
ground covered by them is so vast that only the leading ideas and
experiments can here be touched upon; besides, it is preferable that the
lectures should be carefully gone over for their own sake, it being more
than likely that each student will discover a new beauty or stimulus in
them. Taking up the course of reasoning followed by Mr. Tesla in his
first lecture, it will be noted that he started out with the recognition
of the fact, which he has now experimentally demonstrated, that for the
production of light waves, primarily, electrostatic effects must be
brought into play, and continued study has led him to the opinion that
all electrical and magnetic effects may be referred to electrostatic
molecular forces. This opinion finds a singular confirmation in one of
the most striking experiments which he describes, namely, the production
of a veritable flame by the agitation of electrostatically charged
molecules. It is of the highest interest to observe that this result
points out a way of obtaining a flame which consumes no material and in
which no chemical action whatever takes place. It also throws a light on
the nature of the ordinary flame, which Mr. Tesla believes to be due to
electrostatic molecular actions, which, if true, would lead directly to
the idea that even chemical affinities might be electrostatic in their
nature and that, as has already been suggested, molecular forces in
general may be referable to one and the same cause. This singular
phenomenon accounts in a plausible manner for the unexplained fact that
buildings are frequently set on fire during thunder storms without
having been at all struck by lightning. It may also explain the total
disappearance of ships at sea.

One of the striking proofs of the correctness of the ideas advanced by
Mr. Tesla is the fact that, notwithstanding the employment of the most
powerful electromagnetic inductive effects, but feeble luminosity is
obtainable, and this only in close proximity to the source of
disturbance; whereas, when the electrostatic effects are intensified,
the same initial energy suffices to excite luminosity at considerable
distances from the source. That there are only electrostatic effects
active seems to be clearly proved by Mr. Tesla's experiments with an
induction coil operated with alternating currents of very high
frequency. He shows how tubes may be made to glow brilliantly at
considerable distances from any object when placed in a powerful,
rapidly alternating, electrostatic field, and he describes many
interesting phenomena observed in such a field. His experiments open up
the possibility of lighting an apartment by simply creating in it such
an electrostatic field, and this, in a certain way, would appear to be
the ideal method of lighting a room, as it would allow the illuminating
device to be freely moved about. The power with which these exhausted
tubes, devoid of any electrodes, light up is certainly remarkable.

That the principle propounded by Mr. Tesla is a broad one is evident
from the many ways in which it may be practically applied. We need only
refer to the variety of the devices shown or described, all of which are
novel in character and will, without doubt, lead to further important
results at the hands of Mr. Tesla and other investigators. The
experiment, for instance, of lighting up a single filament or block of
refractory material with a single wire, is in itself sufficient to give
Mr. Tesla's work the stamp of originality, and the numerous other
experiments and effects which may be varied at will, are equally new and
interesting. Thus, the incandescent filament spinning in an unexhausted
globe, the well-known Crookes experiment on open circuit, and the many
others suggested, will not fail to interest the reader. Mr. Tesla has
made an exhaustive study of the various forms of the discharge presented
by an induction coil when operated with these rapidly alternating
currents, starting from the thread-like discharge and passing through
various stages to the true electric flame.

A point of great importance in the introduction of high tension
alternating current which Mr. Tesla brings out is the necessity of
carefully avoiding all gaseous matter in the high tension apparatus. He
shows that, at least with very rapidly alternating currents of high
potential, the discharge may work through almost any practicable
thickness of the best insulators, if air is present. In such cases the
air included within the apparatus is violently agitated and by molecular
bombardment the parts may be so greatly heated as to cause a rupture of
the insulation. The practical outcome of this is, that, whereas with
steady currents, any kind of insulation may be used, with rapidly
alternating currents oils will probably be the best to employ, a fact
which has been observed, but not until now satisfactorily explained. The
recognition of the above fact is of special importance in the
construction of the costly commercial induction coils which are often
rendered useless in an unaccountable manner. The truth of these views of
Mr. Tesla is made evident by the interesting experiments illustrative
of the behavior of the air between charged surfaces, the luminous
streams formed by the charged molecules appearing even when great
thicknesses of the best insulators are interposed between the charged
surfaces. These luminous streams afford in themselves a very interesting
study for the experimenter. With these rapidly alternating currents they
become far more powerful and produce beautiful light effects when they
issue from a wire, pinwheel or other object attached to a terminal of
the coil; and it is interesting to note that they issue from a ball
almost as freely as from a point, when the frequency is very high.

From these experiments we also obtain a better idea of the importance of
taking into account the capacity and self-induction in the apparatus
employed and the possibilities offered by the use of condensers in
conjunction with alternate currents, the employment of currents of high
frequency, among other things, making it possible to reduce the
condenser to practicable dimensions. Another point of interest and
practical bearing is the fact, proved by Mr. Tesla, that for alternate
currents, especially those of high frequency, insulators are required
possessing a small specific inductive capacity, which at the same time
have a high insulating power.

Mr. Tesla also makes interesting and valuable suggestion in regard to
the economical utilization of iron in machines and transformers. He
shows how, by maintaining by continuous magnetization a flow of lines
through the iron, the latter may be kept near its maximum permeability
and a higher output and economy may be secured in such apparatus. This
principle may prove of considerable commercial importance in the
development of alternating systems. Mr. Tesla's suggestion that the same
result can be secured by heating the iron by hysteresis and eddy
currents, and increasing the permeability in this manner, while it may
appear less practical, nevertheless opens another direction for
investigation and improvement.

The demonstration of the fact that with alternating currents of high
frequency, sufficient energy may be transmitted under practicable
conditions through the glass of an incandescent lamp by electrostatic or
electromagnetic induction may lead to a departure in the construction of
such devices. Another important experimental result achieved is the
operation of lamps, and even motors, with the discharges of condensers,
this method affording a means of converting direct or alternating
currents. In this connection Mr. Tesla advocates the perfecting of
apparatus capable of generating electricity of high tension from heat
energy, believing this to be a better way of obtaining electrical energy
for practical purposes, particularly for the production of light.

While many were probably prepared to encounter curious phenomena of
impedance in the use of a condenser discharged disruptively, the
experiments shown were extremely interesting on account of their
paradoxical character. The burning of an incandescent lamp at any candle
power when connected across a heavy metal bar, the existence of nodes on
the bar and the possibility of exploring the bar by means of an ordinary
Cardew voltmeter, are all peculiar developments, but perhaps the most
interesting observation is the phenomenon of impedance observed in the
lamp with a straight filament, which remains dark while the bulb glows.

Mr. Tesla's manner of operating an induction coil by means of the
disruptive discharge, and thus obtaining enormous differences of
potential from comparatively small and inexpensive coils, will be
appreciated by experimenters and will find valuable application in
laboratories. Indeed, his many suggestions and hints in regard to the
construction and use of apparatus in these investigations will be highly
valued and will aid materially in future research.

The London lecture was delivered twice. In its first form, before the
Institution of Electrical Engineers, it was in some respects an
amplification of several points not specially enlarged upon in the New
York lecture, but brought forward many additional discoveries and new
investigations. Its repetition, in another form, at the Royal
Institution, was due to Prof. Dewar, who with Lord Rayleigh, manifested
a most lively interest in Mr. Tesla's work, and whose kindness
illustrated once more the strong English love of scientific truth and
appreciation of its votaries. As an indefatigable experimenter, Mr.
Tesla was certainly nowhere more at home than in the haunts of Faraday,
and as the guest of Faraday's successor. This Royal Institution lecture
summed up the leading points of Mr. Tesla's work, in the high potential,
high frequency field, and we may here avail ourselves of so valuable a
summarization, in a simple form, of a subject by no means easy of
comprehension until it has been thoroughly studied.

In these London lectures, among the many notable points made was first,
the difficulty of constructing the alternators to obtain the very high
frequencies needed. To obtain the high frequencies it was necessary to
provide several hundred polar projections, which were necessarily small
and offered many drawbacks, and this the more as exceedingly high
peripheral speeds had to be resorted to. In some of the first machines
both armature and field had polar projections. These machines produced a
curious noise, especially when the armature was started from the state
of rest, the field being charged. The most efficient machine was found
to be one with a drum armature, the iron body of which consisted of very
thin wire annealed with special care. It was, of course, desirable to
avoid the employment of iron in the armature, and several machines of
this kind, with moving or stationary conductors were constructed, but
the results obtained were not quite satisfactory, on account of the
great mechanical and other difficulties encountered.

The study of the properties of the high frequency currents obtained from
these machines is very interesting, as nearly every experiment discloses
something new. Two coils traversed by such a current attract or repel
each other with a force which, owing to the imperfection of our sense of
touch, seems continuous. An interesting observation, already noted under
another form, is that a piece of iron, surrounded by a coil through
which the current is passing appears to be continuously magnetized. This
apparent continuity might be ascribed to the deficiency of the sense of
touch, but there is evidence that in currents of such high frequencies
one of the impulses preponderates over the other.

As might be expected, conductors traversed by such currents are rapidly
heated, owing to the increase of the resistance, and the heating effects
are relatively much greater in the iron. The hysteresis losses in iron
are so great that an iron core, even if finely subdivided, is heated in
an incredibly short time. To give an idea of this, an ordinary iron wire
1/16 inch in diameter inserted within a coil having 250 turns, with a
current estimated to be five amperes passing through the coil, becomes
within two seconds' time so hot as to scorch wood. Beyond a certain
frequency, an iron core, no matter how finely subdivided, exercises a
dampening effect, and it was easy to find a point at which the
impedance of a coil was not affected by the presence of a core
consisting of a bundle of very thin well annealed and varnished iron
wires.

Experiments with a telephone, a conductor in a strong magnetic field, or
with a condenser or arc, seem to afford certain proof that sounds far
above the usually accepted limit of hearing would be perceived if
produced with sufficient power. The arc produced by these currents
possesses several interesting features. Usually it emits a note the
pitch of which corresponds to twice the frequency of the current, but if
the frequency be sufficiently high it becomes noiseless, the limit of
audition being determined principally by the linear dimensions of the
arc. A curious feature of the arc is its persistency, which is due
partly to the inability of the gaseous column to cool and increase
considerably in resistance, as is the case with low frequencies, and
partly to the tendency of such a high frequency machine to maintain a
constant current.

In connection with these machines the condenser affords a particularly
interesting study. Striking effects are produced by proper adjustments
of capacity and self-induction. It is easy to raise the electromotive
force of the machine to many times the original value by simply
adjusting the capacity of a condenser connected in the induced circuit.
If the condenser be at some distance from the machine, the difference of
potential on the terminals of the latter may be only a small fraction of
that on the condenser.

But the most interesting experiences are gained when the tension of the
currents from the machine is raised by means of an induction coil. In
consequence of the enormous rate of change obtainable in the primary
current, much higher potential differences are obtained than with coils
operated in the usual ways, and, owing to the high frequency, the
secondary discharge possesses many striking peculiarities. Both the
electrodes behave generally alike, though it appears from some
observations that one current impulse preponderates over the other, as
before mentioned.

The physiological effects of the high tension discharge are found to be
so small that the shock of the coil can be supported without any
inconvenience, except perhaps a small burn produced by the discharge
upon approaching the hand to one of the terminals. The decidedly smaller
physiological effects of these currents are thought to be due either to
a different distribution through the body or to the tissues acting as
condensers. But in the case of an induction coil with a great many turns
the harmlessness is principally due to the fact that but little energy
is available in the external circuit when the same is closed through the
experimenter's body, on account of the great impedance of the coil.

In varying the frequency and strength of the currents through the
primary of the coil, the character of the secondary discharge is greatly
varied, and no less than five distinct forms are observed:--A weak,
sensitive thread discharge, a powerful flaming discharge, and three
forms of brush or streaming discharges. Each of these possesses certain
noteworthy features, but the most interesting to study are the latter.

Under certain conditions the streams, which are presumably due to the
violent agitation of the air molecules, issue freely from all points of
the coil, even through a thick insulation. If there is the smallest air
space between the primary and secondary, they will form there and surely
injure the coil by slowly warming the insulation. As they form even with
ordinary frequencies when the potential is excessive, the air-space must
be most carefully avoided. These high frequency streamers differ in
aspect and properties from those produced by a static machine. The wind
produced by them is small and should altogether cease if still
considerably higher frequencies could be obtained. A peculiarity is that
they issue as freely from surfaces as from points. Owing to this, a
metallic vane, mounted in one of the terminals of the coil so as to
rotate freely, and having one of its sides covered with insulation, is
spun rapidly around. Such a vane would not rotate with a steady
potential, but with a high frequency coil it will spin, even if it be
entirely covered with insulation, provided the insulation on one side be
either thicker or of a higher specific inductive capacity. A Crookes
electric radiometer is also spun around when connected to one of the
terminals of the coil, but only at very high exhaustion or at ordinary
pressures.

There is still another and more striking peculiarity of such a high
frequency streamer, namely, it is hot. The heat is easily perceptible
with frequencies of about 10,000, even if the potential is not
excessively high. The heating effect is, of course, due to the molecular
impacts and collisions. Could the frequency and potential be pushed far
enough, then a brush could be produced resembling in every particular a
flame and giving light and heat, yet without a chemical process taking
place.

The hot brush, when properly produced, resembles a jet of burning gas
escaping under great pressure, and it emits an extraordinary strong
smell of ozone. The great ozonizing action is ascribed to the fact that
the agitation of the molecules of the air is more violent in such a
brush than in the ordinary streamer of a static machine. But the most
powerful brush discharges were produced by employing currents of much
higher frequencies than it was possible to obtain by means of the
alternators. These currents were obtained by disruptively discharging a
condenser and setting up oscillations. In this manner currents of a
frequency of several hundred thousand were obtained.

Currents of this kind, Mr. Tesla pointed out, produce striking effects.
At these frequencies, the impedance of a copper bar is so great that a
potential difference of several hundred volts can be maintained between
two points of a short and thick bar, and it is possible to keep an
ordinary incandescent lamp burning at full candle power by attaching the
terminals of the lamp to two points of the bar no more than a few inches
apart. When the frequency is extremely high, nodes are found to exist on
such a bar, and it is easy to locate them by means of a lamp.

By converting the high tension discharges of a low frequency coil in
this manner, it was found practicable to keep a few lamps burning on the
ordinary circuit in the laboratory, and by bringing the undulation to a
low pitch, it was possible to operate small motors.

This plan likewise allows of converting high tension discharges of one
direction into low tension unidirectional currents, by adjusting the
circuit so that there are no oscillations. In passing the oscillating
discharges through the primary of a specially constructed coil, it is
easy to obtain enormous potential differences with only few turns of the
secondary.

Great difficulties were at first experienced in producing a successful
coil on this plan. It was found necessary to keep all air, or gaseous
matter in general, away from the charged surfaces, and oil immersion was
resorted to. The wires used were heavily covered with gutta-percha and
wound in oil, or the air was pumped out by means of a Sprengel pump. The
general arrangement was the following:--An ordinary induction coil,
operated from a low frequency alternator, was used to charge Leyden
jars. The jars were made to discharge over a single or multiple gap
through the primary of the second coil. To insure the action of the gap,
the arc was blown out by a magnet or air blast. To adjust the potential
in the secondary a small oil condenser was used, or polished brass
spheres of different sizes were screwed on the terminals and their
distance adjusted.

When the conditions were carefully determined to suit each experiment,
magnificent effects were obtained. Two wires, stretched through the
room, each being connected to one of the terminals of the coil, emitted
streams so powerful that the light from them allowed distinguishing the
objects in the room; the wires became luminous even though covered with
thick and most excellent insulation. When two straight wires, or two
concentric circles of wire, are connected to the terminals, and set at
the proper distance, a uniform luminous sheet is produced between them.
It was possible in this way to cover an area of more than one meter
square completely with the streams. By attaching to one terminal a large
circle of wire and to the other terminal a small sphere, the streams are
focused upon the sphere, produce a strongly lighted spot upon the same,
and present the appearance of a luminous cone. A very thin wire glued
upon a plate of hard rubber of great thickness, on the opposite side of
which is fastened a tinfoil coating, is rendered intensely luminous when
the coating is connected to the other terminal of the coil. Such an
experiment can be performed also with low frequency currents, but much
less satisfactorily.

When the terminals of such a coil, even of a very small one, are
separated by a rubber or glass plate, the discharge spreads over the
plate in the form of streams, threads or brilliant sparks, and affords a
magnificent display, which cannot be equaled by the largest coil
operated in the usual ways. By a simple adjustment it is possible to
produce with the coil a succession of brilliant sparks, exactly as with
a Holtz machine.

Under certain conditions, when the frequency of the oscillation is very
great, white, phantom-like streams are seen to break forth from the
terminals of the coil. The chief interesting feature about them is, that
they stream freely against the outstretched hand or other conducting
object without producing any sensation, and the hand may be approached
very near to the terminal without a spark being induced to jump. This is
due presumably to the fact that a considerable portion of the energy is
carried away or dissipated in the streamers, and the difference of
potential between the terminal and the hand is diminished.

It is found in such experiments that the frequency of the vibration and
the quickness of succession of the sparks between the knobs affect to a
marked degree the appearance of the streams. When the frequency is very
low, the air gives way in more or less the same manner as by a steady
difference of potential, and the streams consist of distinct threads,
generally mingled with thin sparks, which probably correspond to the
successive discharges occurring between the knobs. But when the
frequency is very high, and the arc of the discharge produces a sound
which is loud and smooth (which indicates both that oscillation takes
place and that the sparks succeed each other with great rapidity), then
the luminous streams formed are perfectly uniform. They are generally of
a purplish hue, but when the molecular vibration is increased by raising
the potential, they assume a white color.

The luminous intensity of the streams increases rapidly when the
potential is increased; and with frequencies of only a few hundred
thousand, could the coil be made to withstand a sufficiently high
potential difference, there is no doubt that the space around a wire
could be made to emit a strong light, merely by the agitation of the
molecules of the air at ordinary pressure.

Such discharges of very high frequency which render luminous the air at
ordinary pressure we have very likely occasion to witness in the aurora
borealis. From many of these experiments it seems reasonable to infer
that sudden cosmic disturbances, such as eruptions on the sun, set the
electrostatic charge of the earth in an extremely rapid vibration, and
produce the glow by the violent agitation of the air in the upper and
even in the lower strata. It is thought that if the frequency were low,
or even more so if the charge were not at all vibrating, the lower dense
strata would break down as in a lightning discharge. Indications of such
breaking down have been repeatedly observed, but they can be attributed
to the fundamental disturbances, which are few in number, for the
superimposed vibration would be so rapid as not to allow a disruptive
break.

The study of these discharge phenomena has led Mr. Tesla to the
recognition of some important facts. It was found, as already stated,
that gaseous matter must be most carefully excluded from any dielectric
which is subjected to great, rapidly changing electrostatic stresses.
Since it is difficult to exclude the gas perfectly when solid insulators
are used, it is necessary to resort to liquid dielectrics. When a solid
dielectric is used, it matters little how thick and how good it is; if
air be present, streamers form, which gradually heat the dielectric and
impair its insulating power, and the discharge finally breaks through.
Under ordinary conditions the best insulators are those which possess
the highest specific inductive capacity, but such insulators are not the
best to employ when working with these high frequency currents, for in
most cases the higher specific inductive capacity is rather a
disadvantage. The prime quality of the insulating medium for these
currents is continuity. For this reason principally it is necessary to
employ liquid insulators, such as oils. If two metal plates, connected
to the terminals of the coil, are immersed in oil and set a distance
apart, the coil may be kept working for any length of time without a
break occurring, or without the oil being warmed, but if air bubbles are
introduced, they become luminous; the air molecules, by their impact
against the oil, heat it, and after some time cause the insulation to
give way. If, instead of the oil, a solid plate of the best dielectric,
even several times thicker than the oil intervening between the metal
plates, is inserted between the latter, the air having free access to
the charged surfaces, the dielectric invariably is warmed and breaks
down.

The employment of oil is advisable or necessary even with low
frequencies, if the potentials are such that streamers form, but only in
such cases, as is evident from the theory of the action. If the
potentials are so low that streamers do not form, then it is even
disadvantageous to employ oil, for it may, principally by confining the
heat, be the cause of the breaking down of the insulation.

The exclusion of gaseous matter is not only desirable on account of the
safety of the apparatus, but also on account of economy, especially in a
condenser, in which considerable waste of power may occur merely owing
to the presence of air, if the electric density on the charged surfaces
is great.

In the course of these investigations a phenomenon of special scientific
interest was observed. It may be ranked among the brush phenomena, in
fact it is a kind of brush which forms at, or near, a single terminal in
high vacuum. In a bulb with a conducting electrode, even if the latter
be of aluminum, the brush has only a very short existence, but it can be
preserved for a considerable length of time in a bulb devoid of any
conducting electrode. To observe the phenomenon it is found best to
employ a large spherical bulb having in its centre a small bulb
supported on a tube sealed to the neck of the former. The large bulb
being exhausted to a high degree, and the inside of the small bulb being
connected to one of the terminals of the coil, under certain conditions
there appears a misty haze around the small bulb, which, after passing
through some stages, assumes the form of a brush, generally at right
angles to the tube supporting the small bulb. When the brush assumes
this form it may be brought to a state of extreme sensitiveness to
electrostatic and magnetic influence. The bulb hanging straight down,
and all objects being remote from it, the approach of the observer
within a few paces will cause the brush to fly to the opposite side, and
if he walks around the bulb it will always keep on the opposite side. It
may begin to spin around the terminal long before it reaches that
sensitive stage. When it begins to turn around, principally, but also
before, it is affected by a magnet, and at a certain stage it is
susceptible to magnetic influence to an astonishing degree. A small
permanent magnet, with its poles at a distance of no more than two
centimetres will affect it visibly at a distance of two metres, slowing
down or accelerating the rotation according to how it is held relatively
to the brush.

When the bulb hangs with the globe down, the rotation is always
clockwise. In the southern hemisphere it would occur in the opposite
direction, and on the (magnetic) equator the brush should not turn at
all. The rotation may be reversed by a magnet kept at some distance. The
brush rotates best, seemingly, when it is at right angles to the lines
of force of the earth. It very likely rotates, when at its maximum
speed, in synchronism with the alternations, say, 10,000 times a second.
The rotation can be slowed down or accelerated by the approach or
recession of the observer, or any conducting body, but it cannot be
reversed by putting the bulb in any position. Very curious experiments
may be performed with the brush when in its most sensitive state. For
instance, the brush resting in one position, the experimenter may, by
selecting a proper position, approach the hand at a certain considerable
distance to the bulb, and he may cause the brush to pass off by merely
stiffening the muscles of the arm, the mere change of configuration of
the arm and the consequent imperceptible displacement being sufficient
to disturb the delicate balance. When it begins to rotate slowly, and
the hands are held at a proper distance, it is impossible to make even
the slightest motion without producing a visible effect upon the brush.
A metal plate connected to the other terminal of the coil affects it at
a great distance, slowing down the rotation often to one turn a second.

Mr. Tesla hopes that this phenomenon will prove a valuable aid in the
investigation of the nature of the forces acting in an electrostatic or
magnetic field. If there is any motion which is measurable going on in
the space, such a brush would be apt to reveal it. It is, so to speak, a
beam of light, frictionless, devoid of inertia. On account of its
marvellous sensitiveness to electrostatic or magnetic disturbances it
may be the means of sending signals through submarine cables with any
speed, and even of transmitting intelligence to a distance without
wires.

In operating an induction coil with these rapidly alternating currents,
it is astonishing to note, for the first time, the great importance of
the relation of capacity, self-induction, and frequency as bearing upon
the general result. The combined effect of these elements produces many
curious effects. For instance, two metal plates are connected to the
terminals and set at a small distance, so that an arc is formed between
them. This arc _prevents_ a strong current from flowing through the
coil. If the arc be interrupted by the interposition of a glass plate,
the capacity of the condenser obtained counteracts the self-induction,
and a stronger current is made to pass. The effects of capacity are the
most striking, for in these experiments, since the self-induction and
frequency both are high, the critical capacity is very small, and need
be but slightly varied to produce a very considerable change. The
experimenter brings his body in contact with the terminals of the
secondary of the coil, or attaches to one or both terminals insulated
bodies of very small bulk, such as exhausted bulbs, and he produces a
considerable rise or fall of potential on the secondary, and greatly
affects the flow of the current through the primary coil.

In many of the phenomena observed, the presence of the air, or,
generally speaking, of a medium of a gaseous nature (using this term not
to imply specific properties, but in contradistinction to homogeneity or
perfect continuity) plays an important part, as it allows energy to be
dissipated by molecular impact or bombardment. The action is thus
explained:--When an insulated body connected to a terminal of the coil
is suddenly charged to high potential, it acts inductively upon the
surrounding air, or whatever gaseous medium there might be. The
molecules or atoms which are near it are, of course, more attracted, and
move through a greater distance than the further ones. When the nearest
molecules strike the body they are repelled, and collisions occur at all
distances within the inductive distance. It is now clear that, if the
potential be steady, but little loss of energy can be caused in this
way, for the molecules which are nearest to the body having had an
additional charge imparted to them by contact, are not attracted until
they have parted, if not with all, at least with most of the additional
charge, which can be accomplished only after a great many collisions.
This is inferred from the fact that with a steady potential there is but
little loss in dry air. When the potential, instead of being steady, is
alternating, the conditions are entirely different. In this case a
rhythmical bombardment occurs, no matter whether the molecules after
coming in contact with the body lose the imparted charge or not, and,
what is more, if the charge is not lost, the impacts are all the more
violent. Still, if the frequency of the impulses be very small, the loss
caused by the impacts and collisions would not be serious unless the
potential was excessive. But when extremely high frequencies and more or
less high potentials are used, the loss may be very great. The total
energy lost per unit of time is proportionate to the product of the
number of impacts per second, or the frequency and the energy lost in
each impact. But the energy of an impact must be proportionate to the
square of the electric density of the body, on the assumption that the
charge imparted to the molecule is proportionate to that density. It is
concluded from this that the total energy lost must be proportionate to
the product of the frequency and the square of the electric density; but
this law needs experimental confirmation. Assuming the preceding
considerations to be true, then, by rapidly alternating the potential of
a body immersed in an insulating gaseous medium, any amount of energy
may be dissipated into space. Most of that energy, then, is not
dissipated in the form of long ether waves, propagated to considerable
distance, as is thought most generally, but is consumed in impact and
collisional losses--that is, heat vibrations--on the surface and in the
vicinity of the body. To reduce the dissipation it is necessary to work
with a small electric density--the smaller, the higher the frequency.

The behavior of a gaseous medium to such rapid alternations of potential
makes it appear plausible that electrostatic disturbances of the earth,
produced by cosmic events, may have great influence upon the
meteorological conditions. When such disturbances occur both the
frequency of the vibrations of the charge and the potential are in all
probability excessive, and the energy converted into heat may be
considerable. Since the density must be unevenly distributed, either in
consequence of the irregularity of the earth's surface, or on account of
the condition of the atmosphere in various places, the effect produced
would accordingly vary from place to place. Considerable variations in
the temperature and pressure of the atmosphere may in this manner be
caused at any point of the surface of the earth. The variations may be
gradual or very sudden, according to the nature of the original
disturbance, and may produce rain and storms, or locally modify the
weather in any way.

From many experiences gathered in the course of these investigations it
appears certain that in lightning discharges the air is an element of
importance. For instance, during a storm a stream may form on a nail or
pointed projection of a building. If lightning strikes somewhere in the
neighborhood, the harmless static discharge may, in consequence of the
oscillations set up, assume the character of a high-frequency streamer,
and the nail or projection may be brought to a high temperature by the
violent impact of the air molecules. Thus, it is thought, a building may
be set on fire without the lightning striking it. In like manner small
metallic objects may be fused and volatilized--as frequently occurs in
lightning discharges--merely because they are surrounded by air. Were
they immersed in a practically continuous medium, such as oil, they
would probably be safe, as the energy would have to spend itself
elsewhere.

An instructive experience having a bearing on this subject is the
following:--A glass tube of an inch or so in diameter and several inches
long is taken, and a platinum wire sealed into it, the wire running
through the center of the tube from end to end. The tube is exhausted to
a moderate degree. If a steady current is passed through the wire it is
heated uniformly in all parts and the gas in the tube is of no
consequence. But if high frequency discharges are directed through the
wire, it is heated more on the ends than in the middle portion, and if
the frequency, or rate of charge, is high enough, the wire might as well
be cut in the middle as not, for most of the heating on the ends is due
to the rarefied gas. Here the gas might only act as a conductor of no
impedance, diverting the current from the wire as the impedance of the
latter is enormously increased, and merely heating the ends of the wire
by reason of their resistance to the passage of the discharge. But it is
not at all necessary that the gas in the tube should be conducting; it
might be at an extremely low pressure, still the ends of the wire would
be heated; however, as is ascertained by experience, only the two ends
would in such case not be electrically connected through the gaseous
medium. Now, what with these frequencies and potentials occurs in an
exhausted tube, occurs in the lightning discharge at ordinary pressure.

From the facility with which any amount of energy may be carried off
through a gas, Mr. Tesla infers that the best way to render harmless a
lightning discharge is to afford it in some way a passage through a
volume of gas.

The recognition of some of the above facts has a bearing upon
far-reaching scientific investigations in which extremely high
frequencies and potentials are used. In such cases the air is an
important factor to be considered. So, for instance, if two wires are
attached to the terminals of the coil, and the streamers issue from
them, there is dissipation of energy in the form of heat and light, and
the wires behave like a condenser of larger capacity. If the wires be
immersed in oil, the dissipation of energy is prevented, or at least
reduced, and the apparent capacity is diminished. The action of the air
would seem to make it very difficult to tell, from the measured or
computed capacity of a condenser in which the air is acted upon, its
actual capacity or vibration period, especially if the condenser is of
very small surface and is charged to a very high potential. As many
important results are dependant upon the correctness of the estimation
of the vibration period, this subject demands the most careful scrutiny
of investigators.

In Leyden jars the loss due to the presence of air is comparatively
small, principally on account of the great surface of the coatings and
the small external action, but if there are streamers on the top, the
loss may be considerable, and the period of vibration is affected. In a
resonator, the density is small, but the frequency is extreme, and may
introduce a considerable error. It appears certain, at any rate, that
the periods of vibration of a charged body in a gaseous and in a
continuous medium, such as oil, are different, on account of the action
of the former, as explained.

Another fact recognized, which is of some consequence, is, that in
similar investigations the general considerations of static screening
are not applicable when a gaseous medium is present. This is evident
from the following experiment:--A short and wide glass tube is taken and
covered with a substantial coating of bronze powder, barely allowing the
light to shine a little through. The tube is highly exhausted and
suspended on a metallic clasp from the end of a wire. When the wire is
connected with one of the terminals of the coil, the gas inside of the
tube is lighted in spite of the metal coating. Here the metal evidently
does not screen the gas inside as it ought to, even if it be very thin
and poorly conducting. Yet, in a condition of rest the metal coating,
however thin, screens the inside perfectly.

One of the most interesting results arrived at in pursuing these
experiments, is the demonstration of the fact that a gaseous medium,
upon which vibration is impressed by rapid changes of electrostatic
potential, is rigid. In illustration of this result an experiment made
by Mr. Tesla may by cited:--A glass tube about one inch in diameter and
three feet long, with outside condenser coatings on the ends, was
exhausted to a certain point, when, the tube being suspended freely from
a wire connecting the upper coating to one of the terminals of the coil,
the discharge appeared in the form of a luminous thread passing through
the axis of the tube. Usually the thread was sharply defined in the
upper part of the tube and lost itself in the lower part. When a magnet
or the finger was quickly passed near the upper part of the luminous
thread, it was brought out of position by magnetic or electrostatic
influence, and a transversal vibration like that of a suspended cord,
with one or more distinct nodes, was set up, which lasted for a few
minutes and gradually died out. By suspending from the lower condenser
coating metal plates of different sizes, the speed of the vibration was
varied. This vibration would seem to show beyond doubt that the thread
possessed rigidity, at least to transversal displacements.

Many experiments were tried to demonstrate this property in air at
ordinary pressure. Though no positive evidence has been obtained, it is
thought, nevertheless, that a high frequency brush or streamer, if the
frequency could be pushed far enough, would be decidedly rigid. A small
sphere might then be moved within it quite freely, but if thrown against
it the sphere would rebound. An ordinary flame cannot possess rigidity
to a marked degree because the vibration is directionless; but an
electric arc, it is believed, must possess that property more or less. A
luminous band excited in a bulb by repeated discharges of a Leyden jar
must also possess rigidity, and if deformed and suddenly released should
vibrate.

From like considerations other conclusions of interest are reached. The
most probable medium filling the space is one consisting of independent
carriers immersed in an insulating fluid. If through this medium
enormous electrostatic stresses are assumed to act, which vary rapidly
in intensity, it would allow the motion of a body through it, yet it
would be rigid and elastic, although the fluid itself might be devoid of
these properties. Furthermore, on the assumption that the independent
carriers are of any configuration such that the fluid resistance to
motion in one direction is greater than in another, a stress of that
nature would cause the carriers to arrange themselves in groups, since
they would turn to each other their sides of the greatest electric
density, in which position the fluid resistance to approach would be
smaller than to receding. If in a medium of the above characteristics a
brush would be formed by a steady potential, an exchange of the carriers
would go on continually, and there would be less carriers per unit of
volume in the brush than in the space at some distance from the
electrode, this corresponding to rarefaction. If the potential were
rapidly changing, the result would be very different; the higher the
frequency of the pulses, the slower would be the exchange of the
carriers; finally, the motion of translation through measurable space
would cease, and, with a sufficiently high frequency and intensity of
the stress, the carriers would be drawn towards the electrode, and
compression would result.

An interesting feature of these high frequency currents is that they
allow of operating all kinds of devices by connecting the device with
only one leading wire to the electric source. In fact, under certain
conditions it may be more economical to supply the electrical energy
with one lead than with two.

An experiment of special interest shown by Mr. Tesla, is the running, by
the use of only one insulated line, of a motor operating on the
principle of the rotating magnetic field enunciated by Mr. Tesla. A
simple form of such a motor is obtained by winding upon a laminated iron
core a primary and close to it a secondary coil, closing the ends of the
latter and placing a freely movable metal disc within the influence of
the moving field. The secondary coil may, however, be omitted. When one
of the ends of the primary coil of the motor is connected to one of the
terminals of the high frequency coil and the other end to an insulated
metal plate, which, it should be stated, is not absolutely necessary for
the success of the experiment, the disc is set in rotation.

Experiments of this kind seem to bring it within possibility to operate
a motor at any point of the earth's surface from a central source,
without any connection to the same except through the earth. If, by
means of powerful machinery, rapid variations of the earth's potential
were produced, a grounded wire reaching up to some height would be
traversed by a current which could be increased by connecting the free
end of the wire to a body of some size. The current might be converted
to low tension and used to operate a motor or other device. The
experiment, which would be one of great scientific interest, would
probably best succeed on a ship at sea. In this manner, even if it were
not possible to operate machinery, intelligence might be transmitted
quite certainly.

In the course of this experimental study special attention was devoted
to the heating effects produced by these currents, which are not only
striking, but open up the possibility of producing a more efficient
illuminant. It is sufficient to attach to the coil terminal a thin wire
or filament, to have the temperature of the latter perceptibly raised.
If the wire or filament be enclosed in a bulb, the heating effect is
increased by preventing the circulation of the air. If the air in the
bulb be strongly compressed, the displacements are smaller, the impacts
less violent, and the heating effect is diminished. On the contrary, if
the air in the bulb be exhausted, an inclosed lamp filament is brought
to incandescence, and any amount of light may thus be produced.

The heating of the inclosed lamp filament depends on so many things of a
different nature, that it is difficult to give a generally applicable
rule under which the maximum heating occurs. As regards the size of the
bulb, it is ascertained that at ordinary or only slightly differing
atmospheric pressures, when air is a good insulator, the filament is
heated more in a small bulb, because of the better confinement of heat
in this case. At lower pressures, when air becomes conducting, the
heating effect is greater in a large bulb, but at excessively high
degrees of exhaustion there seems to be, beyond a certain and rather
small size of the vessel, no perceptible difference in the heating.

The shape of the vessel is also of some importance, and it has been
found of advantage for reasons of economy to employ a spherical bulb
with the electrode mounted in its centre, where the rebounding molecules
collide.

It is desirable on account of economy that all the energy supplied to
the bulb from the source should reach without loss the body to be
heated. The loss in conveying the energy from the source to the body may
be reduced by employing thin wires heavily coated with insulation, and
by the use of electrostatic screens. It is to be remarked, that the
screen cannot be connected to the ground as under ordinary conditions.

In the bulb itself a large portion of the energy supplied may be lost by
molecular bombardment against the wire connecting the body to be heated
with the source. Considerable improvement was effected by covering the
glass stem containing the wire with a closely fitting conducting tube.
This tube is made to project a little above the glass, and prevents the
cracking of the latter near the heated body. The effectiveness of the
conducting tube is limited to very high degrees of exhaustion. It
diminishes the energy lost in bombardment for two reasons; first, the
charge given up by the atoms spreads over a greater area, and hence the
electric density at any point is small, and the atoms are repelled with
less energy than if they would strike against a good insulator;
secondly, as the tube is electrified by the atoms which first come in
contact with it, the progress of the following atoms against the tube is
more or less checked by the repulsion which the electrified tube must
exert upon the similarly electrified atoms. This, it is thought,
explains why the discharge through a bulb is established with much
greater facility when an insulator, than when a conductor, is present.

During the investigations a great many bulbs of different construction,
with electrodes of different material, were experimented upon, and a
number of observations of interest were made. Mr. Tesla has found that
the deterioration of the electrode is the less, the higher the
frequency. This was to be expected, as then the heating is effected by
many small impacts, instead by fewer and more violent ones, which
quickly shatter the structure. The deterioration is also smaller when
the vibration is harmonic. Thus an electrode, maintained at a certain
degree of heat, lasts much longer with currents obtained from an
alternator, than with those obtained by means of a disruptive discharge.
One of the most durable electrodes was obtained from strongly compressed
carborundum, which is a kind of carbon recently produced by Mr. E. G.
Acheson, of Monongahela City, Pa. From experience, it is inferred, that
to be most durable, the electrode should be in the form of a sphere with
a highly polished surface.

In some bulbs refractory bodies were mounted in a carbon cup and put
under the molecular impact. It was observed in such experiments that the
carbon cup was heated at first, until a higher temperature was reached;
then most of the bombardment was directed against the refractory body,
and the carbon was relieved. In general, when different bodies were
mounted in the bulb, the hardest fusible would be relieved, and would
remain at a considerably lower temperature. This was necessitated by the
fact that most of the energy supplied would find its way through the
body which was more easily fused or "evaporated."

Curiously enough it appeared in some of the experiments made, that a
body was fused in a bulb under the molecular impact by evolution of less
light than when fused by the application of heat in ordinary ways. This
may be ascribed to a loosening of the structure of the body under the
violent impacts and changing stresses.

Some experiments seem to indicate that under certain conditions a body,
conducting or nonconducting, may, when bombarded, emit light, which to
all appearances is due to phosphorescence, but may in reality be caused
by the incandescence of an infinitesimal layer, the mean temperature of
the body being comparatively small. Such might be the case if each
single rhythmical impact were capable of instantaneously exciting the
retina, and the rhythm were just high enough to cause a continuous
impression in the eye. According to this view, a coil operated by
disruptive discharge would be eminently adapted to produce such a
result, and it is found by experience that its power of exciting
phosphorescence is extraordinarily great. It is capable of exciting
phosphorescence at comparatively low degrees of exhaustion, and also
projects shadows at pressures far greater than those at which the mean
free path is comparable to the dimensions of the vessel. The latter
observation is of some importance, inasmuch as it may modify the
generally accepted views in regard to the "radiant state" phenomena.

A thought which early and naturally suggested itself to Mr. Tesla, was
to utilize the great inductive effects of high frequency currents to
produce light in a sealed glass vessel without the use of leading in
wires. Accordingly, many bulbs were constructed in which the energy
necessary to maintain a button or filament at high incandescence, was
supplied through the glass by either electrostatic or electrodynamic
induction. It was easy to regulate the intensity of the light emitted by
means of an externally applied condenser coating connected to an
insulated plate, or simply by means of a plate attached to the bulb
which at the same time performed the function of a shade.

A subject of experiment, which has been exhaustively treated in England
by Prof. J. J. Thomson, has been followed up independently by Mr. Tesla
from the beginning of this study, namely, to excite by electrodynamic
induction a luminous band in a closed tube or bulb. In observing the
behavior of gases, and the luminous phenomena obtained, the importance
of the electrostatic effects was noted and it appeared desirable to
produce enormous potential differences, alternating with extreme
rapidity. Experiments in this direction led to some of the most
interesting results arrived at in the course of these investigations. It
was found that by rapid alternations of a high electrostatic potential,
exhausted tubes could be lighted at considerable distances from a
conductor connected to a properly constructed coil, and that it was
practicable to establish with the coil an alternating electrostatic
field, acting through the whole room and lighting a tube wherever it was
placed within the four walls. Phosphorescent bulbs may be excited in
such a field, and it is easy to regulate the effect by connecting to the
bulb a small insulated metal plate. It was likewise possible to maintain
a filament or button mounted in a tube at bright incandescence, and, in
one experiment, a mica vane was spun by the incandescence of a platinum
wire.

Coming now to the lecture delivered in Philadelphia and St. Louis, it
may be remarked that to the superficial reader, Mr. Tesla's
introduction, dealing with the importance of the eye, might appear as a
digression, but the thoughtful reader will find therein much food for
meditation and speculation. Throughout his discourse one can trace Mr.
Tesla's effort to present in a popular way thoughts and views on the
electrical phenomena which have in recent years captivated the
scientific world, but of which the general public has even yet merely
received an inkling. Mr. Tesla also dwells rather extensively on his
well-known method of high-frequency conversion; and the large amount of
detail information will be gratefully received by students and
experimenters in this virgin field. The employment of apt analogies in
explaining the fundamental principles involved makes it easy for all to
gain a clear idea of their nature. Again, the ease with which, thanks to
Mr. Tesla's efforts, these high-frequency currents may now be obtained
from circuits carrying almost any kind of current, cannot fail to result
in an extensive broadening of this field of research, which offers so
many possibilities. Mr. Tesla, true philosopher as he is, does not
hesitate to point out defects in some of his methods, and indicates the
lines which to him seem the most promising. Particular stress is laid by
him upon the employment of a medium in which the discharge electrodes
should be immersed in order that this method of conversion may be
brought to the highest perfection. He has evidently taken pains to give
as much useful information as possible to those who wish to follow in
his path, as he shows in detail the circuit arrangements to be adopted
in all ordinary cases met with in practice, and although some of these
methods were described by him two years before, the additional
information is still timely and welcome.

In his experiments he dwells first on some phenomena produced by
electrostatic force, which he considers in the light of modern theories
to be the most important force in nature for us to investigate. At the
very outset he shows a strikingly novel experiment illustrating the
effect of a rapidly varying electrostatic force in a gaseous medium, by
touching with one hand one of the terminals of a 200,000 volt
transformer and bringing the other hand to the opposite terminal. The
powerful streamers which issued from his hand and astonished his
audiences formed a capital illustration of some of the views advanced,
and afforded Mr. Tesla an opportunity of pointing out the true reasons
why, with these currents, such an amount of energy can be passed
through the body with impunity. He then showed by experiment the
difference between a steady and a rapidly varying force upon the
dielectric. This difference is most strikingly illustrated in the
experiment in which a bulb attached to the end of a wire in connection
with one of the terminals of the transformer is ruptured, although all
extraneous bodies are remote from the bulb. He next illustrates how
mechanical motions are produced by a varying electrostatic force acting
through a gaseous medium. The importance of the action of the air is
particularly illustrated by an interesting experiment.

Taking up another class of phenomena, namely, those of dynamic
electricity, Mr. Tesla produced in a number of experiments a variety of
effects by the employment of only a single wire with the evident intent
of impressing upon his audience the idea that electric vibration or
current can be transmitted with ease, without any return circuit; also
how currents so transmitted can be converted and used for many practical
purposes. A number of experiments are then shown, illustrating the
effects of frequency, self-induction and capacity; then a number of ways
of operating motive and other devices by the use of a single lead. A
number of novel impedance phenomena are also shown which cannot fail to
arouse interest.

Mr. Tesla next dwelt upon a subject which he thinks of great importance,
that is, electrical resonance, which he explained in a popular way. He
expressed his firm conviction that by observing proper conditions,
intelligence, and possibly even power, can be transmitted through the
medium or through the earth; and he considers this problem worthy of
serious and immediate consideration.

Coming now to the light phenomena in particular, he illustrated the four
distinct kinds of these phenomena in an original way, which to many must
have been a revelation. Mr. Tesla attributes these light effects to
molecular or atomic impacts produced by a varying electrostatic stress
in a gaseous medium. He illustrated in a series of novel experiments the
effect of the gas surrounding the conductor and shows beyond a doubt
that with high frequency and high potential currents, the surrounding
gas is of paramount importance in the heating of the conductor. He
attributes the heating partially to a conduction current and partially
to bombardment, and demonstrates that in many cases the heating may be
practically due to the bombardment alone. He pointed out also that the
skin effect is largely modified by the presence of the gas or of an
atomic medium in general. He showed also some interesting experiments in
which the effect of convection is illustrated. Probably one of the most
curious experiments in this connection is that in which a thin platinum
wire stretched along the axis of an exhausted tube is brought to
incandescence at certain points corresponding to the position of the
striae, while at others it remains dark. This experiment throws an
interesting light upon the nature of the striae and may lead to important
revelations.

Mr. Tesla also demonstrated the dissipation of energy through an atomic
medium and dwelt upon the behavior of vacuous space in conveying heat,
and in this connection showed the curious behavior of an electrode
stream, from which he concludes that the molecules of a gas probably
cannot be acted upon directly at measurable distances.

Mr. Tesla summarized the chief results arrived at in pursuing his
investigations in a manner which will serve as a valuable guide to all
who may engage in this work. Perhaps most interest will centre on his
general statements regarding the phenomena of phosphorescence, the most
important fact revealed in this direction being that when exciting a
phosphorescent bulb a certain definite potential gives the most
economical result.

The lectures will now be presented in the order of their date of
delivery.




CHAPTER XXVI.

EXPERIMENTS WITH ALTERNATE CURRENTS OF VERY HIGH FREQUENCY AND THEIR
APPLICATION TO METHODS OF ARTIFICIAL ILLUMINATION.[1]

  [1] A lecture delivered before the American Institute of
      Electrical Engineers, at Columbia College, N. Y.,
      May 20, 1891.


There is no subject more captivating, more worthy of study, than nature.
To understand this great mechanism, to discover the forces which are
active, and the laws which govern them, is the highest aim of the
intellect of man.

Nature has stored up in the universe infinite energy. The eternal
recipient and transmitter of this infinite energy is the ether. The
recognition of the existence of ether, and of the functions it performs,
is one of the most important results of modern scientific research. The
mere abandoning of the idea of action at a distance, the assumption of a
medium pervading all space and connecting all gross matter, has freed
the minds of thinkers of an ever present doubt, and, by opening a new
horizon--new and unforeseen possibilities--has given fresh interest to
phenomena with which we are familiar of old. It has been a great step
towards the understanding of the forces of nature and their multifold
manifestations to our senses. It has been for the enlightened student of
physics what the understanding of the mechanism of the firearm or of the
steam engine is for the barbarian. Phenomena upon which we used to look
as wonders baffling explanation, we now see in a different light. The
spark of an induction coil, the glow of an incandescent lamp, the
manifestations of the mechanical forces of currents and magnets are no
longer beyond our grasp; instead of the incomprehensible, as before,
their observation suggests now in our minds a simple mechanism, and
although as to its precise nature all is still conjecture, yet we know
that the truth cannot be much longer hidden, and instinctively we feel
that the understanding is dawning upon us. We still admire these
beautiful phenomena, these strange forces, but we are helpless no
longer; we can in a certain measure explain them, account for them, and
we are hopeful of finally succeeding in unraveling the mystery which
surrounds them.

In how far we can understand the world around us is the ultimate thought
of every student of nature. The coarseness of our senses prevents us
from recognizing the ulterior construction of matter, and astronomy,
this grandest and most positive of natural sciences, can only teach us
something that happens, as it were, in our immediate neighborhood: of
the remoter portions of the boundless universe, with its numberless
stars and suns, we know nothing. But far beyond the limit of perception
of our senses the spirit still can guide us, and so we may hope that
even these unknown worlds--infinitely small and great--may in a measure
become known to us. Still, even if this knowledge should reach us, the
searching mind will find a barrier, perhaps forever unsurpassable, to
the _true_ recognition of that which _seems_ to be, the mere
_appearance_ of which is the only and slender basis of all our
philosophy.

Of all the forms of nature's immeasurable, all-pervading energy, which
ever and ever changing and moving, like a soul animates the inert
universe, electricity and magnetism are perhaps the most fascinating.
The effects of gravitation, of heat and light we observe daily, and soon
we get accustomed to them, and soon they lose for us the character of
the marvelous and wonderful; but electricity and magnetism, with their
singular relationship, with their seemingly dual character, unique among
the forces in nature, with their phenomena of attractions, repulsions
and rotations, strange manifestations of mysterious agents, stimulate
and excite the mind to thought and research. What is electricity, and
what is magnetism? These questions have been asked again and again. The
most able intellects have ceaselessly wrestled with the problem; still
the question has not as yet been fully answered. But while we cannot
even to-day state what these singular forces are, we have made good
headway towards the solution of the problem. We are now confident that
electric and magnetic phenomena are attributable to ether, and we are
perhaps justified in saying that the effects of static electricity are
effects of ether under strain, and those of dynamic electricity and
electro-magnetism effects of ether in motion. But this still leaves the
question, as to what electricity and magnetism are, unanswered.

First, we naturally inquire, What is electricity, and is there such a
thing as electricity? In interpreting electric phenomena, we may speak
of electricity or of an electric condition, state or effect. If we speak
of electric effects we must distinguish two such effects, opposite in
character and neutralizing each other, as observation shows that two
such opposite effects exist. This is unavoidable, for in a medium of the
properties of ether, we cannot possibly exert a strain, or produce a
displacement or motion of any kind, without causing in the surrounding
medium an equivalent and opposite effect. But if we speak of
electricity, meaning a _thing_, we must, I think, abandon the idea of
two electricities, as the existence of two such things is highly
improbable. For how can we imagine that there should be two things,
equivalent in amount, alike in their properties, but of opposite
character, both clinging to matter, both attracting and completely
neutralizing each other? Such an assumption, though suggested by many
phenomena, though most convenient for explaining them, has little to
commend it. If there _is_ such a thing as electricity, there can be only
_one_ such thing, and excess and want of that one thing, possibly; but
more probably its condition determines the positive and negative
character. The old theory of Franklin, though falling short in some
respects, is, from a certain point of view, after all, the most
plausible one. Still, in spite of this, the theory of the two
electricities is generally accepted, as it apparently explains electric
phenomena in a more satisfactory manner. But a theory which better
explains the facts is not necessarily true. Ingenious minds will invent
theories to suit observation, and almost every independent thinker has
his own views on the subject.

It is not with the object of advancing an opinion, but with the desire
of acquainting you better with some of the results, which I will
describe, to show you the reasoning I have followed, the departures I
have made--that I venture to express, in a few words, the views and
convictions which have led me to these results.

I adhere to the idea that there is a thing which we have been in the
habit of calling electricity. The question is, What is that thing? or,
What, of all things, the existence of which we know, have we the best
reason to call electricity? We know that it acts like an incompressible
fluid; that there must be a constant quantity of it in nature; that it
can be neither produced nor destroyed; and, what is more important, the
electro-magnetic theory of light and all facts observed teach us that
electric and ether phenomena are identical. The idea at once suggests
itself, therefore, that electricity might be called ether. In fact, this
view has in a certain sense been advanced by Dr. Lodge. His interesting
work has been read by everyone and many have been convinced by his
arguments. His great ability and the interesting nature of the subject,
keep the reader spellbound; but when the impressions fade, one realizes
that he has to deal only with ingenious explanations. I must confess,
that I cannot believe in two electricities, much less in a
doubly-constituted ether. The puzzling behavior of the ether as a solid
to waves of light and heat, and as a fluid to the motion of bodies
through it, is certainly explained in the most natural and satisfactory
manner by assuming it to be in motion, as Sir William Thomson has
suggested; but regardless of this, there is nothing which would enable
us to conclude with certainty that, while a fluid is not capable of
transmitting transverse vibrations of a few hundred or thousand per
second, it might not be capable of transmitting such vibrations when
they range into hundreds of million millions per second. Nor can anyone
prove that there are transverse ether waves emitted from an alternate
current machine, giving a small number of alternations per second; to
such slow disturbances, the ether, if at rest, may behave as a true
fluid.

Returning to the subject, and bearing in mind that the existence of two
electricities is, to say the least, highly improbable, we must remember,
that we have no evidence of electricity, nor can we hope to get it,
unless gross matter is present. Electricity, therefore, cannot be called
ether in the broad sense of the term; but nothing would seem to stand in
the way of calling electricity ether associated with matter, or bound
ether; or, in other words, that the so-called static charge of the
molecule is ether associated in some way with the molecule. Looking at
it in that light, we would be justified in saying, that electricity is
concerned in all molecular actions.

Now, precisely what the ether surrounding the molecules is, wherein it
differs from ether in general, can only be conjectured. It cannot differ
in density, ether being incompressible: it must, therefore, be under
some strain or in motion, and the latter is the most probable. To
understand its functions, it would be necessary to have an exact idea of
the physical construction of matter, of which, of course, we can only
form a mental picture.

But of all the views on nature, the one which assumes one matter and one
force, and a perfect uniformity throughout, is the most scientific and
most likely to be true. An infinitesimal world, with the molecules and
their atoms spinning and moving in orbits, in much the same manner as
celestial bodies, carrying with them and probably spinning with them
ether, or in other words, carrying with them static charges, seems to my
mind the most probable view, and one which, in a plausible manner,
accounts for most of the phenomena observed. The spinning of the
molecules and their ether sets up the ether tensions or electrostatic
strains; the equalization of ether tensions sets up ether motions or
electric currents, and the orbital movements produce the effects of
electro and permanent magnetism.

About fifteen years ago, Prof. Rowland demonstrated a most interesting
and important fact, namely, that a static charge carried around produces
the effects of an electric current. Leaving out of consideration the
precise nature of the mechanism, which produces the attraction and
repulsion of currents, and conceiving the electrostatically charged
molecules in motion, this experimental fact gives us a fair idea of
magnetism. We can conceive lines or tubes of force which physically
exist, being formed of rows of directed moving molecules; we can see
that these lines must be closed, that they must tend to shorten and
expand, etc. It likewise explains in a reasonable way, the most puzzling
phenomenon of all, permanent magnetism, and, in general, has all the
beauties of the Ampere theory without possessing the vital defect of the
same, namely, the assumption of molecular currents. Without enlarging
further upon the subject, I would say, that I look upon all
electrostatic, current and magnetic phenomena as being due to
electrostatic molecular forces.

The preceding remarks I have deemed necessary to a full understanding of
the subject as it presents itself to my mind.

Of all these phenomena the most important to study are the current
phenomena, on account of the already extensive and ever-growing use of
currents for industrial purposes. It is now a century since the first
practical source of current was produced, and, ever since, the phenomena
which accompany the flow of currents have been diligently studied, and
through the untiring efforts of scientific men the simple laws which
govern them have been discovered. But these laws are found to hold good
only when the currents are of a steady character. When the currents are
rapidly varying in strength, quite different phenomena, often
unexpected, present themselves, and quite different laws hold good,
which even now have not been determined as fully as is desirable, though
through the work, principally, of English scientists, enough knowledge
has been gained on the subject to enable us to treat simple cases which
now present themselves in daily practice.

The phenomena which are peculiar to the changing character of the
currents are greatly exalted when the rate of change is increased, hence
the study of these currents is considerably facilitated by the
employment of properly constructed apparatus. It was with this and other
objects in view that I constructed alternate current machines capable of
giving more than two million reversals of current per minute, and to
this circumstance it is principally due, that I am able to bring to your
attention some of the results thus far reached, which I hope will prove
to be a step in advance on account of their direct bearing upon one of
the most important problems, namely, the production of a practical and
efficient source of light.

The study of such rapidly alternating currents is very interesting.
Nearly every experiment discloses something new. Many results may, of
course, be predicted, but many more are unforeseen. The experimenter
makes many interesting observations. For instance, we take a piece of
iron and hold it against a magnet. Starting from low alternations and
running up higher and higher we feel the impulses succeed each other
faster and faster, get weaker and weaker, and finally disappear. We then
observe a continuous pull; the pull, of course, is not continuous; it
only appears so to us; our sense of touch is imperfect.

We may next establish an arc between the electrodes and observe, as the
alternations rise, that the note which accompanies alternating arcs gets
shriller and shriller, gradually weakens, and finally ceases. The air
vibrations, of course, continue, but they are too weak to be perceived;
our sense of hearing fails us.

We observe the small physiological effects, the rapid heating of the
iron cores and conductors, curious inductive effects, interesting
condenser phenomena, and still more interesting light phenomena with a
high tension induction coil. All these experiments and observations
would be of the greatest interest to the student, but their description
would lead me too far from the principal subject. Partly for this
reason, and partly on account of their vastly greater importance, I will
confine myself to the description of the light effects produced by these
currents.

In the experiments to this end a high tension induction coil or
equivalent apparatus for converting currents of comparatively low into
currents of high tension is used.

If you will be sufficiently interested in the results I shall describe
as to enter into an experimental study of this subject; if you will be
convinced of the truth of the arguments I shall advance--your aim will
be to produce high frequencies and high potentials; in other words,
powerful electrostatic effects. You will then encounter many
difficulties, which, if completely overcome, would allow us to produce
truly wonderful results.

First will be met the difficulty of obtaining the required frequencies
by means of mechanical apparatus, and, if they be obtained otherwise,
obstacles of a different nature will present themselves. Next it will be
found difficult to provide the requisite insulation without considerably
increasing the size of the apparatus, for the potentials required are
high, and, owing to the rapidity of the alternations, the insulation
presents peculiar difficulties. So, for instance, when a gas is present,
the discharge may work, by the molecular bombardment of the gas and
consequent heating, through as much as an inch of the best solid
insulating material, such as glass, hard rubber, porcelain, sealing wax,
etc.; in fact, through any known insulating substance. The chief
requisite in the insulation of the apparatus is, therefore, the
exclusion of any gaseous matter.

In general my experience tends to show that bodies which possess the
highest specific inductive capacity, such as glass, afford a rather
inferior insulation to others, which, while they are good insulators,
have a much smaller specific inductive capacity, such as oils, for
instance, the dielectric losses being no doubt greater in the former.
The difficulty of insulating, of course, only exists when the potentials
are excessively high, for with potentials such as a few thousand volts
there is no particular difficulty encountered in conveying currents from
a machine giving, say, 20,000 alternations per second, to quite a
distance. This number of alternations, however, is by far too small for
many purposes, though quite sufficient for some practical applications.
This difficulty of insulating is fortunately not a vital drawback; it
affects mostly the size of the apparatus, for, when excessively high
potentials would be used, the light-giving devices would be located not
far from the apparatus, and often they would be quite close to it. As
the air-bombardment of the insulated wire is dependent on condenser
action, the loss may be reduced to a trifle by using excessively thin
wires heavily insulated.

Another difficulty will be encountered in the capacity and
self-induction necessarily possessed by the coil. If the coil be large,
that is, if it contain a great length of wire, it will be generally
unsuited for excessively high frequencies; if it be small, it may be
well adapted for such frequencies, but the potential might then not be
as high as desired. A good insulator, and preferably one possessing a
small specific inductive capacity, would afford a two-fold advantage.
First, it would enable us to construct a very small coil capable of
withstanding enormous differences of potential; and secondly, such a
small coil, by reason of its smaller capacity and self-induction, would
be capable of a quicker and more vigorous vibration. The problem then of
constructing a coil or induction apparatus of any kind possessing the
requisite qualities I regard as one of no small importance, and it has
occupied me for a considerable time.

The investigator who desires to repeat the experiments which I will
describe, with an alternate current machine, capable of supplying
currents of the desired frequency, and an induction coil, will do well
to take the primary coil out and mount the secondary in such a manner as
to be able to look through the tube upon which the secondary is wound.
He will then be able to observe the streams which pass from the primary
to the insulating tube, and from their intensity he will know how far he
can strain the coil. Without this precaution he is sure to injure the
insulation. This arrangement permits, however, an easy exchange of the
primaries, which is desirable in these experiments.

The selection of the type of machine best suited for the purpose must be
left to the judgment of the experimenter. There are here illustrated
three distinct types of machines, which, besides others, I have used in
my experiments.

Fig. 97 represents the machine used in my experiments before this
Institute. The field magnet consists of a ring of wrought iron with 384
pole projections. The armature comprises a steel disc to which is
fastened a thin, carefully welded rim of wrought iron. Upon the rim are
wound several layers of fine, well annealed iron wire, which, when
wound, is passed through shellac. The armature wires are wound around
brass pins, wrapped with silk thread. The diameter of the armature wire
in this type of machine should not be more than 1/6 of the thickness of
the pole projections, else the local action will be considerable.

[Illustration: FIG. 97.]

Fig. 98 represents a larger machine of a different type. The field
magnet of this machine consists of two like parts which either enclose
an exciting coil, or else are independently wound. Each part has 480
pole projections, the projections of one facing those of the other. The
armature consists of a wheel of hard bronze, carrying the conductors
which revolve between the projections of the field magnet. To wind the
armature conductors, I have found it most convenient to proceed in the
following manner. I construct a ring of hard bronze of the required
size. This ring and the rim of the wheel are provided with the proper
number of pins, and both fastened upon a plate. The armature conductors
being wound, the pins are cut off and the ends of the conductors
fastened by two rings which screw to the bronze ring and the rim of the
wheel, respectively. The whole may then be taken off and forms a solid
structure. The conductors in such a type of machine should consist of
sheet copper, the thickness of which, of course, depends on the
thickness of the pole projections; or else twisted thin wires should be
employed.

Fig. 99 is a smaller machine, in many respects similar to the former,
only here the armature conductors and the exciting coil are kept
stationary, while only a block of wrought iron is revolved.

[Illustration: FIG. 98.]

It would be uselessly lengthening this description were I to dwell more
on the details of construction of these machines. Besides, they have
been described somewhat more elaborately in _The Electrical Engineer_,
of March 18, 1891. I deem it well, however, to call the attention of the
investigator to two things, the importance of which, though self
evident, he is nevertheless apt to underestimate; namely, to the local
action in the conductors which must be carefully avoided, and to the
clearance, which must be small. I may add, that since it is desirable to
use very high peripheral speeds, the armature should be of very large
diameter in order to avoid impracticable belt speeds. Of the several
types of these machines which have been constructed by me, I have found
that the type illustrated in Fig. 97 caused me the least trouble in
construction, as well as in maintenance, and on the whole, it has been a
good experimental machine.

In operating an induction coil with very rapidly alternating currents,
among the first luminous phenomena noticed are naturally those presented
by the high-tension discharge. As the number of alternations per second
is increased, or as--the number being high--the current through the
primary is varied, the discharge gradually changes in appearance. It
would be difficult to describe the minor changes which occur, and the
conditions which bring them about, but one may note five distinct forms
of the discharge.

[Illustration: FIG. 99.]

First, one may observe a weak, sensitive discharge in the form of a
thin, feeble-colored thread. (Fig. 100a.) It always occurs when, the
number of alternations per second being high, the current through the
primary is very small. In spite of the excessively small current, the
rate of change is great, and the difference of potential at the
terminals of the secondary is therefore considerable, so that the arc is
established at great distances; but the quantity of "electricity" set in
motion is insignificant, barely sufficient to maintain a thin,
threadlike arc. It is excessively sensitive and may be made so to such a
degree that the mere act of breathing near the coil will affect it, and
unless it is perfectly well protected from currents of air, it wriggles
around constantly. Nevertheless, it is in this form excessively
persistent, and when the terminals are approached to, say, one-third of
the striking distance, it can be blown out only with difficulty. This
exceptional persistency, when short, is largely due to the arc being
excessively thin; presenting, therefore, a very small surface to the
blast. Its great sensitiveness, when very long, is probably due to the
motion of the particles of dust suspended in the air.

[Illustration: FIG. 100a.]

[Illustration: FIG. 100b.]

When the current through the primary is increased, the discharge gets
broader and stronger, and the effect of the capacity of the coil becomes
visible until, finally, under proper conditions, a white flaming arc,
Fig. 100 B, often as thick as one's finger, and striking across the
whole coil, is produced. It develops remarkable heat, and may be further
characterized by the absence of the high note which accompanies the
less powerful discharges. To take a shock from the coil under these
conditions would not be advisable, although under different conditions,
the potential being much higher, a shock from the coil may be taken with
impunity. To produce this kind of discharge the number of alternations
per second must not be too great for the coil used; and, generally
speaking, certain relations between capacity, self-induction and
frequency must be observed.

The importance of these elements in an alternate current circuit is now
well-known, and under ordinary conditions, the general rules are
applicable. But in an induction coil exceptional conditions prevail.
First, the self-induction is of little importance before the arc is
established, when it asserts itself, but perhaps never as prominently as
in ordinary alternate current circuits, because the capacity is
distributed all along the coil, and by reason of the fact that the coil
usually discharges through very great resistances; hence the currents
are exceptionally small. Secondly, the capacity goes on increasing
continually as the potential rises, in consequence of absorption which
takes place to a considerable extent. Owing to this there exists no
critical relationship between these quantities, and ordinary rules would
not seem to be applicable. As the potential is increased either in
consequence of the increased frequency or of the increased current
through the primary, the amount of the energy stored becomes greater and
greater, and the capacity gains more and more in importance. Up to a
certain point the capacity is beneficial, but after that it begins to be
an enormous drawback. It follows from this that each coil gives the best
result with a given frequency and primary current. A very large coil,
when operated with currents of very high frequency, may not give as much
as 1/8 inch spark. By adding capacity to the terminals, the condition
may be improved, but what the coil really wants is a lower frequency.

When the flaming discharge occurs, the conditions are evidently such
that the greatest current is made to flow through the circuit. These
conditions may be attained by varying the frequency within wide limits,
but the highest frequency at which the flaming arc can still be
produced, determines, for a given primary current, the maximum striking
distance of the coil. In the flaming discharge the _eclat_ effect of the
capacity is not perceptible; the rate at which the energy is being
stored then just equals the rate at which it can be disposed of through
the circuit. This kind of discharge is the severest test for a coil; the
break, when it occurs, is of the nature of that in an overcharged Leyden
jar. To give a rough approximation I would state that, with an ordinary
coil of, say 10,000 ohms resistance, the most powerful arc would be
produced with about 12,000 alternations per second.

When the frequency is increased beyond that rate, the potential, of
course, rises, but the striking distance may, nevertheless, diminish,
paradoxical as it may seem. As the potential rises the coil attains more
and more the properties of a static machine until, finally, one may
observe the beautiful phenomenon of the streaming discharge, Fig. 101,
which may be produced across the whole length of the coil. At that stage
streams begin to issue freely from all points and projections. These
streams will also be seen to pass in abundance in the space between the
primary and the insulating tube. When the potential is excessively high
they will always appear, even if the frequency be low, and even if the
primary be surrounded by as much as an inch of wax, hard rubber, glass,
or any other insulating substance. This limits greatly the output of the
coil, but I will later show how I have been able to overcome to a
considerable extent this disadvantage in the ordinary coil.

Besides the potential, the intensity of the streams depends on the
frequency; but if the coil be very large they show themselves, no matter
how low the frequencies used. For instance, in a very large coil of a
resistance of 67,000 ohms, constructed by me some time ago, they appear
with as low as 100 alternations per second and less, the insulation of
the secondary being 3/4 inch of ebonite. When very intense they produce
a noise similar to that produced by the charging of a Holtz machine, but
much more powerful, and they emit a strong smell of ozone. The lower the
frequency, the more apt they are to suddenly injure the coil. With
excessively high frequencies they may pass freely without producing any
other effect than to heat the insulation slowly and uniformly.

[Illustration: FIG. 101.]

[Illustration: FIG. 102.]

The existence of these streams shows the importance of constructing an
expensive coil so as to permit of one's seeing through the tube
surrounding the primary, and the latter should be easily exchangeable;
or else the space between the primary and secondary should be completely
filled up with insulating material so as to exclude all air. The
non-observance of this simple rule in the construction of commercial
coils is responsible for the destruction of many an expensive coil.

At the stage when the streaming discharge occurs, or with somewhat
higher frequencies, one may, by approaching the terminals quite nearly,
and regulating properly the effect of capacity, produce a veritable
spray of small silver-white sparks, or a bunch of excessively thin
silvery threads (Fig. 102) amidst a powerful brush--each spark or thread
possibly corresponding to one alternation. This, when produced under
proper conditions, is probably the most beautiful discharge, and when an
air blast is directed against it, it presents a singular appearance. The
spray of sparks, when received through the body, causes some
inconvenience, whereas, when the discharge simply streams, nothing at
all is likely to be felt if large conducting objects are held in the
hands to protect them from receiving small burns.

If the frequency is still more increased, then the coil refuses to give
any spark unless at comparatively small distances, and the fifth typical
form of discharge may be observed (Fig. 103). The tendency to stream out
and dissipate is then so great that when the brush is produced at one
terminal no sparking occurs, even if, as I have repeatedly tried, the
hand, or any conducting object, is held within the stream; and, what is
more singular, the luminous stream is not at all easily deflected by the
approach of a conducting body.

[Illustration: FIG. 103.]

[Illustration: FIG. 104.]

At this stage the streams seemingly pass with the greatest freedom
through considerable thicknesses of insulators, and it is particularly
interesting to study their behavior. For this purpose it is convenient
to connect to the terminals of the coil two metallic spheres which may
be placed at any desired distance, Fig. 104. Spheres are preferable to
plates, as the discharge can be better observed. By inserting dielectric
bodies between the spheres, beautiful discharge phenomena may be
observed. If the spheres be quite close and a spark be playing between
them, by interposing a thin plate of ebonite between the spheres the
spark instantly ceases and the discharge spreads into an intensely
luminous circle several inches in diameter, provided the spheres are
sufficiently large. The passage of the streams heats, and, after a
while, softens, the rubber so much that two plates may be made to stick
together in this manner. If the spheres are so far apart that no spark
occurs, even if they are far beyond the striking distance, by inserting
a thick plate of glass the discharge is instantly induced to pass from
the spheres to the glass in the form of luminous streams. It appears
almost as though these streams pass _through_ the dielectric. In reality
this is not the case, as the streams are due to the molecules of the air
which are violently agitated in the space between the oppositely charged
surfaces of the spheres. When no dielectric other than air is present,
the bombardment goes on, but is too weak to be visible; by inserting a
dielectric the inductive effect is much increased, and besides, the
projected air molecules find an obstacle and the bombardment becomes so
intense that the streams become luminous. If by any mechanical means we
could effect such a violent agitation of the molecules we could produce
the same phenomenon. A jet of air escaping through a small hole under
enormous pressure and striking against an insulating substance, such as
glass, may be luminous in the dark, and it might be possible to produce
a phosphorescence of the glass or other insulators in this manner.

The greater the specific inductive capacity of the interposed
dielectric, the more powerful the effect produced. Owing to this, the
streams show themselves with excessively high potentials even if the
glass be as much as one and one-half to two inches thick. But besides
the heating due to bombardment, some heating goes on undoubtedly in the
dielectric, being apparently greater in glass than in ebonite. I
attribute this to the greater specific inductive capacity of the glass,
in consequence of which, with the same potential difference, a greater
amount of energy is taken up in it than in rubber. It is like connecting
to a battery a copper and a brass wire of the same dimensions. The
copper wire, though a more perfect conductor, would heat more by reason
of its taking more current. Thus what is otherwise considered a virtue
of the glass is here a defect. Glass usually gives way much quicker than
ebonite; when it is heated to a certain degree, the discharge suddenly
breaks through at one point, assuming then the ordinary form of an arc.

The heating effect produced by molecular bombardment of the dielectric
would, of course, diminish as the pressure of the air is increased, and
at enormous pressure it would be negligible, unless the frequency would
increase correspondingly.

It will be often observed in these experiments that when the spheres are
beyond the striking distance, the approach of a glass plate, for
instance, may induce the spark to jump between the spheres. This occurs
when the capacity of the spheres is somewhat below the critical value
which gives the greatest difference of potential at the terminals of the
coil. By approaching a dielectric, the specific inductive capacity of
the space between the spheres is increased, producing the same effect as
if the capacity of the spheres were increased. The potential at the
terminals may then rise so high that the air space is cracked. The
experiment is best performed with dense glass or mica.

Another interesting observation is that a plate of insulating material,
when the discharge is passing through it, is strongly attracted by
either of the spheres, that is by the nearer one, this being obviously
due to the smaller mechanical effect of the bombardment on that side,
and perhaps also to the greater electrification.

From the behavior of the dielectrics in these experiments, we may
conclude that the best insulator for these rapidly alternating currents
would be the one possessing the smallest specific inductive capacity and
at the same time one capable of withstanding the greatest differences of
potential; and thus two diametrically opposite ways of securing the
required insulation are indicated, namely, to use either a perfect
vacuum or a gas under great pressure; but the former would be
preferable. Unfortunately neither of these two ways is easily carried
out in practice.

It is especially interesting to note the behavior of an excessively high
vacuum in these experiments. If a test tube, provided with external
electrodes and exhausted to the highest possible degree, be connected to
the terminals of the coil, Fig. 105, the electrodes of the tube are
instantly brought to a high temperature and the glass at each end of the
tube is rendered intensely phosphorescent, but the middle appears
comparatively dark, and for a while remains cool.

When the frequency is so high that the discharge shown in Fig. 103 is
observed, considerable dissipation no doubt occurs in the coil.
Nevertheless the coil may be worked for a long time, as the heating is
gradual.

In spite of the fact that the difference of potential may be enormous,
little is felt when the discharge is passed through the body, provided
the hands are armed. This is to some extent due to the higher frequency,
but principally to the fact that less energy is available externally,
when the difference of potential reaches an enormous value, owing to the
circumstance that, with the rise of potential, the energy absorbed in
the coil increases as the square of the potential. Up to a certain point
the energy available externally increases with the rise of potential,
then it begins to fall off rapidly. Thus, with the ordinary high tension
induction coil, the curious paradox exists, that, while with a given
current through the primary the shock might be fatal, with many times
that current it might be perfectly harmless, even if the frequency be
the same. With high frequencies and excessively high potentials when the
terminals are not connected to bodies of some size, practically all the
energy supplied to the primary is taken up by the coil. There is no
breaking through, no local injury, but all the material, insulating and
conducting, is uniformly heated.

[Illustration: FIG. 105.]

[Illustration: FIG. 106.]

To avoid misunderstanding in regard to the physiological effect of
alternating currents of very high frequency, I think it necessary to
state that, while it is an undeniable fact that they are incomparably
less dangerous than currents of low frequencies, it should not be
thought that they are altogether harmless. What has just been said
refers only to currents from an ordinary high tension induction coil,
which currents are necessarily very small; if received directly from a
machine or from a secondary of low resistance, they produce more or less
powerful effects, and may cause serious injury, especially when used in
conjunction with condensers.

The streaming discharge of a high tension induction coil differs in many
respects from that of a powerful static machine. In color it has neither
the violet of the positive, nor the brightness of the negative, static
discharge, but lies somewhere between, being, of course, alternatively
positive and negative. But since the streaming is more powerful when the
point or terminal is electrified positively, than when electrified
negatively, it follows that the point of the brush is more like the
positive, and the root more like the negative, static discharge. In the
dark, when the brush is very powerful, the root may appear almost white.
The wind produced by the escaping streams, though it may be very
strong--often indeed to such a degree that it may be felt quite a
distance from the coil--is, nevertheless, considering the quantity of
the discharge, smaller than that produced by the positive brush of a
static machine, and it affects the flame much less powerfully. From the
nature of the phenomenon we can conclude that the higher the frequency,
the smaller must, of course, be the wind produced by the streams, and
with sufficiently high frequencies no wind at all would be produced at
the ordinary atmospheric pressures. With frequencies obtainable by means
of a machine, the mechanical effect is sufficiently great to revolve,
with considerable speed, large pin-wheels, which in the dark present a
beautiful appearance owing to the abundance of the streams (Fig. 106).

[Illustration: FIG. 107.]

[Illustration: FIG. 108.]

In general, most of the experiments usually performed with a static
machine can be performed with an induction coil when operated with very
rapidly alternating currents. The effects produced, however, are much
more striking, being of incomparably greater power. When a small length
of ordinary cotton covered wire, Fig. 107, is attached to one terminal
of the coil, the streams issuing from all points of the wire may be so
intense as to produce a considerable light effect. When the potentials
and frequencies are very high, a wire insulated with gutta percha or
rubber and attached to one of the terminals, appears to be covered with
a luminous film. A very thin bare wire when attached to a terminal emits
powerful streams and vibrates continually to and fro or spins in a
circle, producing a singular effect (Fig. 108). Some of these
experiments have been described by me in _The Electrical World_, of
February 21, 1891.

Another peculiarity of the rapidly alternating discharge of the
induction coil is its radically different behavior with respect to
points and rounded surfaces.

If a thick wire, provided with a ball at one end and with a point at the
other, be attached to the positive terminal of a static machine,
practically all the charge will be lost through the point, on account of
the enormously greater tension, dependent on the radius of curvature.
But if such a wire is attached to one of the terminals of the induction
coil, it will be observed that with very high frequencies streams issue
from the ball almost as copiously as from the point (Fig. 109).

It is hardly conceivable that we could produce such a condition to an
equal degree in a static machine, for the simple reason, that the
tension increases as the square of the density, which in turn is
proportional to the radius of curvature; hence, with a steady potential
an enormous charge would be required to make streams issue from a
polished ball while it is connected with a point. But with an induction
coil the discharge of which alternates with great rapidity it is
different. Here we have to deal with two distinct tendencies. First,
there is the tendency to escape which exists in a condition of rest, and
which depends on the radius of curvature; second, there is the tendency
to dissipate into the surrounding air by condenser action, which depends
on the surface. When one of these tendencies is a maximum, the other is
at a minimum. At the point the luminous stream is principally due to the
air molecules coming bodily in contact with the point; they are
attracted and repelled, charged and discharged, and, their atomic
charges being thus disturbed, vibrate and emit light waves. At the ball,
on the contrary, there is no doubt that the effect is to a great extent
produced inductively, the air molecules not _necessarily_ coming in
contact with the ball, though they undoubtedly do so. To convince
ourselves of this we only need to exalt the condenser action, for
instance, by enveloping the ball, at some distance, by a better
conductor than the surrounding medium, the conductor being, of course,
insulated; or else by surrounding it with a better dielectric and
approaching an insulated conductor; in both cases the streams will break
forth more copiously. Also, the larger the ball with a given frequency,
or the higher the frequency, the more will the ball have the advantage
over the point. But, since a certain intensity of action is required to
render the streams visible, it is obvious that in the experiment
described the ball should not be taken too large.

In consequence of this two-fold tendency, it is possible to produce by
means of points, effects identical to those produced by capacity. Thus,
for instance, by attaching to one terminal of the coil a small length of
soiled wire, presenting many points and offering great facility to
escape, the potential of the coil may be raised to the same value as by
attaching to the terminal a polished ball of a surface many times
greater than that of the wire.

[Illustration: FIG. 109.]

[Illustration: FIG. 110.]

An interesting experiment, showing the effect of the points, may be
performed in the following manner: Attach to one of the terminals of the
coil a cotton covered wire about two feet in length, and adjust the
conditions so that streams issue from the wire. In this experiment the
primary coil should be preferably placed so that it extends only about
half way into the secondary coil. Now touch the free terminal of the
secondary with a conducting object held in the hand, or else connect it
to an insulated body of some size. In this manner the potential on the
wire may be enormously raised. The effect of this will be either to
increase, or to diminish, the streams. If they increase, the wire is too
short; if they diminish, it is too long. By adjusting the length of the
wire, a point is found where the touching of the other terminal does not
at all affect the streams. In this case the rise of potential is exactly
counteracted by the drop through the coil. It will be observed that
small lengths of wire produce considerable difference in the magnitude
and luminosity of the streams. The primary coil is placed sidewise for
two reasons: First, to increase the potential at the wire; and, second,
to increase the drop through the coil. The sensitiveness is thus
augmented.

There is still another and far more striking peculiarity of the brush
discharge produced by very rapidly alternating currents. To observe this
it is best to replace the usual terminals of the coil by two metal
columns insulated with a good thickness of ebonite. It is also well to
close all fissures and cracks with wax so that the brushes cannot form
anywhere except at the tops of the columns. If the conditions are
carefully adjusted--which, of course, must be left to the skill of the
experimenter--so that the potential rises to an enormous value, one may
produce two powerful brushes several inches long, nearly white at their
roots, which in the dark bear a striking resemblance to two flames of a
gas escaping under pressure (Fig. 110). But they do not only _resemble_,
they _are_ veritable flames, for they are hot. Certainly they are not as
hot as a gas burner, _but they would be so if the frequency and the
potential would be sufficiently high_. Produced with, say, twenty
thousand alternations per second, the heat is easily perceptible even if
the potential is not excessively high. The heat developed is, of course,
due to the impact of the air molecules against the terminals and against
each other. As, at the ordinary pressures, the mean free path is
excessively small, it is possible that in spite of the enormous initial
speed imparted to each molecule upon coming in contact with the
terminal, its progress--by collision with other molecules--is retarded
to such an extent, that it does not get away far from the terminal, but
may strike the same many times in succession. The higher the frequency,
the less the molecule is able to get away, and this the more so, as for
a given effect the potential required is smaller; and a frequency is
conceivable--perhaps even obtainable--at which practically the same
molecules would strike the terminal. Under such conditions the exchange
of the molecules would be very slow, and the heat produced at, and very
near, the terminal would be excessive. But if the frequency would go on
increasing constantly, the heat produced would begin to diminish for
obvious reasons. In the positive brush of a static machine the exchange
of the molecules is very rapid, the stream is constantly of one
direction, and there are fewer collisions; hence the heating effect must
be very small. Anything that impairs the facility of exchange tends to
increase the local heat produced. Thus, if a bulb be held over the
terminal of the coil so as to enclose the brush, the air contained in
the bulb is very quickly brought to a high temperature. If a glass tube
be held over the brush so as to allow the draught to carry the brush
upwards, scorching hot air escapes at the top of the tube. Anything held
within the brush is, of course, rapidly heated, and the possibility of
using such heating effects for some purpose or other suggests itself.

When contemplating this singular phenomenon of the hot brush, we cannot
help being convinced that a similar process must take place in the
ordinary flame, and it seems strange that after all these centuries past
of familiarity with the flame, now, in this era of electric lighting and
heating, we are finally led to recognize, that since time immemorial we
have, after all, always had "electric light and heat" at our disposal.
It is also of no little interest to contemplate, that we have a possible
way of producing--by other than chemical means--a veritable flame, which
would give light and heat without any material being consumed, without
any chemical process taking place, and to accomplish this, we only need
to perfect methods of producing enormous frequencies and potentials. I
have no doubt that if the potential could be made to alternate with
sufficient rapidity and power, the brush formed at the end of a wire
would lose its electrical characteristics and would become flamelike.
The flame must be due to electrostatic molecular action.

This phenomenon now explains in a manner which can hardly be doubted the
frequent accidents occurring in storms. It is well known that objects
are often set on fire without the lightning striking them. We shall
presently see how this can happen. On a nail in a roof, for instance, or
on a projection of any kind, more or less conducting, or rendered so by
dampness, a powerful brush may appear. If the lightning strikes
somewhere in the neighborhood the enormous potential may be made to
alternate or fluctuate perhaps many million times a second. The air
molecules are violently attracted and repelled, and by their impact
produce such a powerful heating effect that a fire is started. It is
conceivable that a ship at sea may, in this manner, catch fire at many
points at once. When we consider, that even with the comparatively low
frequencies obtained from a dynamo machine, and with potentials of no
more than one or two hundred thousand volts, the heating effects are
considerable, we may imagine how much more powerful they must be with
frequencies and potentials many times greater; and the above explanation
seems, to say the least, very probable. Similar explanations may have
been suggested, but I am not aware that, up to the present, the heating
effects of a brush produced by a rapidly alternating potential have been
experimentally demonstrated, at least not to such a remarkable degree.

[Illustration: FIG. 111.]

By preventing completely the exchange of the air molecules, the local
heating effect may be so exalted as to bring a body to incandescence.
Thus, for instance, if a small button, or preferably a very thin wire or
filament be enclosed in an unexhausted globe and connected with the
terminal of the coil, it may be rendered incandescent. The phenomenon is
made much more interesting by the rapid spinning round in a circle of
the top of the filament, thus presenting the appearance of a luminous
funnel, Fig. 111, which widens when the potential is increased. When the
potential is small the end of the filament may perform irregular
motions, suddenly changing from one to the other, or it may describe an
ellipse; but when the potential is very high it always spins in a
circle; and so does generally a thin straight wire attached freely to
the terminal of the coil. These motions are, of course, due to the
impact of the molecules, and the irregularity in the distribution of the
potential, owing to the roughness and dissymmetry of the wire or
filament. With a perfectly symmetrical and polished wire such motions
would probably not occur. That the motion is not likely to be due to
others causes is evident from the fact that it is not of a definite
direction, and that in a very highly exhausted globe it ceases
altogether. The possibility of bringing a body to incandescence in an
exhausted globe, or even when not at all enclosed, would seem to afford
a possible way of obtaining light effects, which, in perfecting methods
of producing rapidly alternating potentials, might be rendered available
for useful purposes.

[Illustration: FIG. 112a.]

In employing a commercial coil, the production of very powerful brush
effects is attended with considerable difficulties, for when these high
frequencies and enormous potentials are used, the best insulation is apt
to give way. Usually the coil is insulated well enough to stand the
strain from convolution to convolution, since two double silk covered
paraffined wires will withstand a pressure of several thousand volts;
the difficulty lies principally in preventing the breaking through from
the secondary to the primary, which is greatly facilitated by the
streams issuing from the latter. In the coil, of course, the strain is
greatest from section to section, but usually in a larger coil there are
so many sections that the danger of a sudden giving way is not very
great. No difficulty will generally be encountered in that direction,
and besides, the liability of injuring the coil internally is very much
reduced by the fact that the effect most likely to be produced is simply
a gradual heating, which, when far enough advanced, could not fail to
be observed. The principal necessity is then to prevent the streams
between the primary and the tube, not only on account of the heating and
possible injury, but also because the streams may diminish very
considerably the potential difference available at the terminals. A few
hints as to how this may be accomplished will probably be found useful
in most of these experiments with the ordinary induction coil.

[Illustration: FIG. 112b.]

One of the ways is to wind a short primary, Fig. 112a, so that the
difference of potential is not at that length great enough to cause the
breaking forth of the streams through the insulating tube. The length of
the primary should be determined by experiment. Both the ends of the
coil should be brought out on one end through a plug of insulating
material fitting in the tube as illustrated. In such a disposition one
terminal of the secondary is attached to a body, the surface of which is
determined with the greatest care so as to produce the greatest rise in
the potential. At the other terminal a powerful brush appears, which may
be experimented upon.

The above plan necessitates the employment of a primary of comparatively
small size, and it is apt to heat when powerful effects are desirable
for a certain length of time. In such a case it is better to employ a
larger coil, Fig. 112b, and introduce it from one side of the tube,
until the streams begin to appear. In this case the nearest terminal of
the secondary may be connected to the primary or to the ground, which is
practically the same thing, if the primary is connected directly to the
machine. In the case of ground connections it is well to determine
experimentally the frequency which is best suited under the conditions
of the test. Another way of obviating the streams, more or less, is to
make the primary in sections and supply it from separate, well insulated
sources.

In many of these experiments, when powerful effects are wanted for a
short time, it is advantageous to use iron cores with the primaries. In
such case a very large primary coil may be wound and placed side by side
with the secondary, and, the nearest terminal of the latter being
connected to the primary, a laminated iron core is introduced through
the primary into the secondary as far as the streams will permit. Under
these conditions an excessively powerful brush, several inches long,
which may be appropriately called "St. Elmo's hot fire," may be caused
to appear at the other terminal of the secondary, producing striking
effects. It is a most powerful ozonizer, so powerful indeed, that only a
few minutes are sufficient to fill the whole room with the smell of
ozone, and it undoubtedly possesses the quality of exciting chemical
affinities.

For the production of ozone, alternating currents of very high frequency
are eminently suited, not only on account of the advantages they offer
in the way of conversion but also because of the fact, that the
ozonizing action of a discharge is dependent on the frequency as well as
on the potential, this being undoubtedly confirmed by observation.

In these experiments if an iron core is used it should be carefully
watched, as it is apt to get excessively hot in an incredibly short
time. To give an idea of the rapidity of the heating, I will state, that
by passing a powerful current through a coil with many turns, the
inserting within the same of a thin iron wire for no more than one
second's time is sufficient to heat the wire to something like 100 deg. C.

But this rapid heating need not discourage us in the use of iron cores
in connection with rapidly alternating currents. I have for a long time
been convinced that in the industrial distribution by means of
transformers, some such plan as the following might be practicable. We
may use a comparatively small iron core, subdivided, or perhaps not even
subdivided. We may surround this core with a considerable thickness of
material which is fire-proof and conducts the heat poorly, and on top of
that we may place the primary and secondary windings. By using either
higher frequencies or greater magnetizing forces, we may by hysteresis
and eddy currents heat the iron core so far as to bring it nearly to its
maximum permeability, which, as Hopkinson has shown, may be as much as
sixteen times greater than that at ordinary temperatures. If the iron
core were perfectly enclosed, it would not be deteriorated by the heat,
and, if the enclosure of fire-proof material would be sufficiently
thick, only a limited amount of energy could be radiated in spite of the
high temperature. Transformers have been constructed by me on that plan,
but for lack of time, no thorough tests have as yet been made.

Another way of adapting the iron core to rapid alternations, or,
generally speaking, reducing the frictional losses, is to produce by
continuous magnetization a flow of something like seven thousand or
eight thousand lines per square centimetre through the core, and then
work with weak magnetizing forces and preferably high frequencies around
the point of greatest permeability. A higher efficiency of conversion
and greater output are obtainable in this manner. I have also employed
this principle in connection with machines in which there is no reversal
of polarity. In these types of machines, as long as there are only few
pole projections, there is no great gain, as the maxima and minima of
magnetization are far from the point of maximum permeability; but when
the number of the pole projections is very great, the required rate of
change may be obtained, without the magnetization varying so far as to
depart greatly from the point of maximum permeability, and the gain is
considerable.

The above described arrangements refer only to the use of commercial
coils as ordinarily constructed. If it is desired to construct a coil
for the express purpose of performing with it such experiments as I have
described, or, generally, rendering it capable of withstanding the
greatest possible difference of potential, then a construction as
indicated in Fig. 113 will be found of advantage. The coil in this case
is formed of two independent parts which are wound oppositely, the
connection between both being made near the primary. The potential in
the middle being zero, there is not much tendency to jump to the primary
and not much insulation is required. In some cases the middle point may,
however, be connected to the primary or to the ground. In such a coil
the places of greatest difference of potential are far apart and the
coil is capable of withstanding an enormous strain. The two parts may be
movable so as to allow a slight adjustment of the capacity effect.

As to the manner of insulating the coil, it will be found convenient to
proceed in the following way: First, the wire should be boiled in
paraffine until all the air is out; then the coil is wound by running
the wire through melted paraffine, merely for the purpose of fixing the
wire. The coil is then taken off from the spool, immersed in a
cylindrical vessel filled with pure melted wax and boiled for a long
time until the bubbles cease to appear. The whole is then left to cool
down thoroughly, and then the mass is taken out of the vessel and turned
up in a lathe. A coil made in this manner and with care is capable of
withstanding enormous potential differences.

[Illustration: FIG. 113.]

It may be found convenient to immerse the coil in paraffine oil or some
other kind of oil; it is a most effective way of insulating, principally
on account of the perfect exclusion of air, but it may be found that,
after all, a vessel filled with oil is not a very convenient thing to
handle in a laboratory.

If an ordinary coil can be dismounted, the primary may be taken out of
the tube and the latter plugged up at one end, filled with oil, and the
primary reinserted. This affords an excellent insulation and prevents
the formation of the streams.

Of all the experiments which may be performed with rapidly alternating
currents the most interesting are those which concern the production of
a practical illuminant. It cannot be denied that the present methods,
though they were brilliant advances, are very wasteful. Some better
methods must be invented, some more perfect apparatus devised. Modern
research has opened new possibilities for the production of an efficient
source of light, and the attention of all has been turned in the
direction indicated by able pioneers. Many have been carried away by
the enthusiasm and passion to discover, but in their zeal to reach
results, some have been misled. Starting with the idea of producing
electro-magnetic waves, they turned their attention, perhaps, too much
to the study of electro-magnetic effects, and neglected the study of
electrostatic phenomena. Naturally, nearly every investigator availed
himself of an apparatus similar to that used in earlier experiments. But
in those forms of apparatus, while the electro-magnetic inductive
effects are enormous, the electrostatic effects are excessively small.

In the Hertz experiments, for instance, a high tension induction coil is
short circuited by an arc, the resistance of which is very small, the
smaller, the more capacity is attached to the terminals; and the
difference of potential at these is enormously diminished. On the other
hand, when the discharge is not passing between the terminals, the
static effects may be considerable, but only qualitatively so, not
quantitatively, since their rise and fall is very sudden, and since
their frequency is small. In neither case, therefore, are powerful
electrostatic effects perceivable. Similar conditions exist when, as in
some interesting experiments of Dr. Lodge, Leyden jars are discharged
disruptively. It has been thought--and I believe asserted--that in such
cases most of the energy is radiated into space. In the light of the
experiments which I have described above, it will now not be thought so.
I feel safe in asserting that in such cases most of the energy is partly
taken up and converted into heat in the arc of the discharge and in the
conducting and insulating material of the jar, some energy being, of
course, given off by electrification of the air; but the amount of the
directly radiated energy is very small.

When a high tension induction coil, operated by currents alternating
only 20,000 times a second, has its terminals closed through even a very
small jar, practically all the energy passes through the dielectric of
the jar, which is heated, and the electrostatic effects manifest
themselves outwardly only to a very weak degree. Now the external
circuit of a Leyden jar, that is, the arc and the connections of the
coatings, may be looked upon as a circuit generating alternating
currents of excessively high frequency and fairly high potential, which
is closed through the coatings and the dielectric between them, and from
the above it is evident that the external electrostatic effects must be
very small, even if a recoil circuit be used. These conditions make it
appear that with the apparatus usually at hand, the observation of
powerful electrostatic effects was impossible, and what experience has
been gained in that direction is only due to the great ability of the
investigators.

But powerful electrostatic effects are a _sine qua non_ of light
production on the lines indicated by theory. Electro-magnetic effects
are primarily unavailable, for the reason that to produce the required
effects we would have to pass current impulses through a conductor,
which, long before the required frequency of the impulses could be
reached, would cease to transmit them. On the other hand,
electro-magnetic waves many times longer than those of light, and
producible by sudden discharge of a condenser, could not be utilized, it
would seem, except we avail ourselves of their effect upon conductors as
in the present methods, which are wasteful. We could not affect by means
of such waves the static molecular or atomic charges of a gas, cause
them to vibrate and to emit light. Long transverse waves cannot,
apparently, produce such effects, since excessively small
electro-magnetic disturbances may pass readily through miles of air.
Such dark waves, unless they are of the length of true light waves,
cannot, it would seem, excite luminous radiation in a Geissler tube, and
the luminous effects, which are producible by induction in a tube devoid
of electrodes, I am inclined to consider as being of an electrostatic
nature.

To produce such luminous effects, straight electrostatic thrusts are
required; these, whatever be their frequency, may disturb the molecular
charges and produce light. Since current impulses of the required
frequency cannot pass through a conductor of measurable dimensions, we
must work with a gas, and then the production of powerful electrostatic
effects becomes an imperative necessity.

It has occurred to me, however, that electrostatic effects are in many
ways available for the production of light. For instance, we may place a
body of some refractory material in a closed, and preferably more or
less exhausted, globe, connect it to a source of high, rapidly
alternating potential, causing the molecules of the gas to strike it
many times a second at enormous speeds, and in this manner, with
trillions of invisible hammers, pound it until it gets incandescent; or
we may place a body in a very highly exhausted globe, in a non-striking
vacuum, and, by employing very high frequencies and potentials,
transfer sufficient energy from it to other bodies in the vicinity, or
in general to the surroundings, to maintain it at any degree of
incandescence; or we may, by means of such rapidly alternating high
potentials, disturb the ether carried by the molecules of a gas or their
static charges, causing them to vibrate and to emit light.

But, electrostatic effects being dependent upon the potential and
frequency, to produce the most powerful action it is desirable to
increase both as far as practicable. It may be possible to obtain quite
fair results by keeping either of these factors small, provided the
other is sufficiently great; but we are limited in both directions. My
experience demonstrates that we cannot go below a certain frequency,
for, first, the potential then becomes so great that it is dangerous;
and, secondly, the light production is less efficient.

I have found that, by using the ordinary low frequencies, the
physiological effect of the current required to maintain at a certain
degree of brightness a tube four feet long, provided at the ends with
outside and inside condenser coatings, is so powerful that, I think, it
might produce serious injury to those not accustomed to such shocks;
whereas, with twenty thousand alternations per second, the tube may be
maintained at the same degree of brightness without any effect being
felt. This is due principally to the fact that a much smaller potential
is required to produce the same light effect, and also to the higher
efficiency in the light production. It is evident that the efficiency in
such cases is the greater, the higher the frequency, for the quicker the
process of charging and discharging the molecules, the less energy will
be lost in the form of dark radiation. But, unfortunately, we cannot go
beyond a certain frequency on account of the difficulty of producing and
conveying the effects.

I have stated above that a body inclosed in an unexhausted bulb may be
intensely heated by simply connecting it with a source of rapidly
alternating potential. The heating in such a case is, in all
probability, due mostly to the bombardment of the molecules of the gas
contained in the bulb. When the bulb is exhausted, the heating of the
body is much more rapid, and there is no difficulty whatever in bringing
a wire or filament to any degree of incandescence by simply connecting
it to one terminal of a coil of the proper dimensions. Thus, if the
well-known apparatus of Prof. Crookes, consisting of a bent platinum
wire with vanes mounted over it (Fig. 114), be connected to one
terminal of the coil--either one or both ends of the platinum wire being
connected--the wire is rendered almost instantly incandescent, and the
mica vanes are rotated as though a current from a battery were used. A
thin carbon filament, or, preferably, a button of some refractory
material (Fig. 115), even if it be a comparatively poor conductor,
inclosed in an exhausted globe, may be rendered highly incandescent; and
in this manner a simple lamp capable of giving any desired candle power
is provided.

The success of lamps of this kind would depend largely on the selection
of the light-giving bodies contained within the bulb. Since, under the
conditions described, refractory bodies--which are very poor conductors
and capable of withstanding for a long time excessively high degrees of
temperature--may be used, such illuminating devices may be rendered
successful.

[Illustration: FIG. 114.]

[Illustration: FIG. 115.]

It might be thought at first that if the bulb, containing the filament
or button of refractory material, be perfectly well exhausted--that is,
as far as it can be done by the use of the best apparatus--the heating
would be much less intense, and that in a perfect vacuum it could not
occur at all. This is not confirmed by my experience; quite the
contrary, the better the vacuum the more easily the bodies are brought
to incandescence. This result is interesting for many reasons.

At the outset of this work the idea presented itself to me, whether two
bodies of refractory material enclosed in a bulb exhausted to such a
degree that the discharge of a large induction coil, operated in the
usual manner, cannot pass through, could be rendered incandescent by
mere condenser action. Obviously, to reach this result enormous
potential differences and very high frequencies are required, as is
evident from a simple calculation.

But such a lamp would possess a vast advantage over an ordinary
incandescent lamp in regard to efficiency. It is well-known that the
efficiency of a lamp is to some extent a function of the degree of
incandescence, and that, could we but work a filament at many times
higher degrees of incandescence, the efficiency would be much greater.
In an ordinary lamp this is impracticable on account of the destruction
of the filament, and it has been determined by experience how far it is
advisable to push the incandescence. It is impossible to tell how much
higher efficiency could be obtained if the filament could withstand
indefinitely, as the investigation to this end obviously cannot be
carried beyond a certain stage; but there are reasons for believing that
it would be very considerably higher. An improvement might be made in
the ordinary lamp by employing a short and thick carbon; but then the
leading-in wires would have to be thick, and, besides, there are many
other considerations which render such a modification entirely
impracticable. But in a lamp as above described, the leading in wires
may be very small, the incandescent refractory material may be in the
shape of blocks offering a very small radiating surface, so that less
energy would be required to keep them at the desired incandescence; and
in addition to this, the refractory material need not be carbon, but may
be manufactured from mixtures of oxides, for instance, with carbon or
other material, or may be selected from bodies which are practically
non-conductors, and capable of withstanding enormous degrees of
temperature.

All this would point to the possibility of obtaining a much higher
efficiency with such a lamp than is obtainable in ordinary lamps. In my
experience it has been demonstrated that the blocks are brought to high
degrees of incandescence with much lower potentials than those
determined by calculation, and the blocks may be set at greater
distances from each other. We may freely assume, and it is probable,
that the molecular bombardment is an important element in the heating,
even if the globe be exhausted with the utmost care, as I have done; for
although the number of the molecules is, comparatively speaking,
insignificant, yet on account of the mean free path being very great,
there are fewer collisions, and the molecules may reach much higher
speeds, so that the heating effect due to this cause may be
considerable, as in the Crookes experiments with radiant matter.

But it is likewise possible that we have to deal here with an increased
facility of losing the charge in very high vacuum, when the potential is
rapidly alternating, in which case most of the heating would be directly
due to the surging of the charges in the heated bodies. Or else the
observed fact may be largely attributable to the effect of the points
which I have mentioned above, in consequence of which the blocks or
filaments contained in the vacuum are equivalent to condensers of many
times greater surface than that calculated from their geometrical
dimensions. Scientific men still differ in opinion as to whether a
charge should, or should not, be lost in a perfect vacuum, or in other
words, whether ether is, or is not, a conductor. If the former were the
case, then a thin filament enclosed in a perfectly exhausted globe, and
connected to a source of enormous, steady potential, would be brought to
incandescence.

[Illustration: FIG. 116.]

[Illustration: FIG. 117.]

Various forms of lamps on the above described principle, with the
refractory bodies in the form of filaments, Fig. 116, or blocks, Fig.
117, have been constructed and operated by me, and investigations are
being carried on in this line. There is no difficulty in reaching such
high degrees of incandescence that ordinary carbon is to all appearance
melted and volatilized. If the vacuum could be made absolutely perfect,
such a lamp, although inoperative with apparatus ordinarily used, would,
if operated with currents of the required character, afford an
illuminant which would never be destroyed, and which would be far more
efficient than an ordinary incandescent lamp. This perfection can, of
course, never be reached, and a very slow destruction and gradual
diminution in size always occurs, as in incandescent filaments; but
there is no possibility of a sudden and premature disabling which occurs
in the latter by the breaking of the filament, especially when the
incandescent bodies are in the shape of blocks.

With these rapidly alternating potentials there is, however, no
necessity of enclosing two blocks in a globe, but a single block, as in
Fig. 115, or filament, Fig. 118, may be used. The potential in this case
must of course be higher, but is easily obtainable, and besides it is
not necessarily dangerous.

[Illustration: FIG. 118.]

The facility with which the button or filament in such a lamp is brought
to incandescence, other things being equal, depends on the size of the
globe. If a perfect vacuum could be obtained, the size of the globe
would not be of importance, for then the heating would be wholly due to
the surging of the charges, and all the energy would be given off to the
surroundings by radiation. But this can never occur in practice. There
is always some gas left in the globe, and although the exhaustion may be
carried to the highest degree, still the space inside of the bulb must
be considered as conducting when such high potentials are used, and I
assume that, in estimating the energy that may be given off from the
filament to the surroundings, we may consider the inside surface of the
bulb as one coating of a condenser, the air and other objects
surrounding the bulb forming the other coating. When the alternations
are very low there is no doubt that a considerable portion of the energy
is given off by the electrification of the surrounding air.

In order to study this subject better, I carried on some experiments
with excessively high potentials and low frequencies. I then observed
that when the hand is approached to the bulb,--the filament being
connected with one terminal of the coil,--a powerful vibration is felt,
being due to the attraction and repulsion of the molecules of the air
which are electrified by induction through the glass. In some cases when
the action is very intense I have been able to hear a sound, which must
be due to the same cause.

[Illustration: FIG. 119.]

[Illustration: FIG. 120.]

When the alternations are low, one is apt to get an excessively powerful
shock from the bulb. In general, when one attaches bulbs or objects of
some size to the terminals of the coil, one should look out for the rise
of potential, for it may happen that by merely connecting a bulb or
plate to the terminal, the potential may rise to many times its original
value. When lamps are attached to the terminals, as illustrated in Fig.
119, then the capacity of the bulbs should be such as to give the
maximum rise of potential under the existing conditions. In this manner
one may obtain the required potential with fewer turns of wire.

The life of such lamps as described above depends, of course, largely on
the degree of exhaustion, but to some extent also on the shape of the
block of refractory material. Theoretically it would seem that a small
sphere of carbon enclosed in a sphere of glass would not suffer
deterioration from molecular bombardment, for, the matter in the globe
being radiant, the molecules would move in straight lines, and would
seldom strike the sphere obliquely. An interesting thought in connection
with such a lamp is, that in it "electricity" and electrical energy
apparently must move in the same lines.

[Illustration: FIG. 121a.]

[Illustration: FIG. 121b.]

The use of alternating currents of very high frequency makes it possible
to transfer, by electrostatic or electromagnetic induction through the
glass of a lamp, sufficient energy to keep a filament at incandescence
and so do away with the leading-in wires. Such lamps have been proposed,
but for want of proper apparatus they have not been successfully
operated. Many forms of lamps on this principle with continuous and
broken filaments have been constructed by me and experimented upon. When
using a secondary enclosed within the lamp, a condenser is
advantageously combined with the secondary. When the transference is
effected by electrostatic induction, the potentials used are, of course,
very high with frequencies obtainable from a machine. For instance, with
a condenser surface of forty square centimetres, which is not
impracticably large, and with glass of good quality 1 mm. thick, using
currents alternating twenty thousand times a second, the potential
required is approximately 9,000 volts. This may seem large, but since
each lamp may be included in the secondary of a transformer of very
small dimensions, it would not be inconvenient, and, moreover, it would
not produce fatal injury. The transformers would all be preferably in
series. The regulation would offer no difficulties, as with currents of
such frequencies it is very easy to maintain a constant current.

In the accompanying engravings some of the types of lamps of this kind
are shown. Fig. 120 is such a lamp with a broken filament, and Figs. 121
A and 121 B one with a single outside and inside coating and a single
filament. I have also made lamps with two outside and inside coatings
and a continuous loop connecting the latter. Such lamps have been
operated by me with current impulses of the enormous frequencies
obtainable by the disruptive discharge of condensers.

The disruptive discharge of a condenser is especially suited for
operating such lamps--with no outward electrical connections--by means
of electromagnetic induction, the electromagnetic inductive effects
being excessively high; and I have been able to produce the desired
incandescence with only a few short turns of wire. Incandescence may
also be produced in this manner in a simple closed filament.

Leaving now out of consideration the practicability of such lamps, I
would only say that they possess a beautiful and desirable feature,
namely, that they can be rendered, at will, more or less brilliant
simply by altering the relative position of the outside and inside
condenser coatings, or inducing and induced circuits.

When a lamp is lighted by connecting it to one terminal only of the
source, this may be facilitated by providing the globe with an outside
condenser coating, which serves at the same time as a reflector, and
connecting this to an insulated body of some size. Lamps of this kind
are illustrated in Fig. 122 and Fig. 123. Fig. 124 shows the plan of
connection. The brilliancy of the lamp may, in this case, be regulated
within wide limits by varying the size of the insulated metal plate to
which the coating is connected.

It is likewise practicable to light with one leading wire lamps such as
illustrated in Fig. 116 and Fig. 117, by connecting one terminal of the
lamp to one terminal of the source, and the other to an insulated body
of the required size. In all cases the insulated body serves to give off
the energy into the surrounding space, and is equivalent to a return
wire. Obviously, in the two last-named cases, instead of connecting the
wires to an insulated body, connections may be made to the ground.

The experiments which will prove most suggestive and of most interest to
the investigator are probably those performed with exhausted tubes. As
might be anticipated, a source of such rapidly alternating potentials is
capable of exciting the tubes at a considerable distance, and the light
effects produced are remarkable.

[Illustration: FIG. 122.]

[Illustration: FIG. 123.]

During my investigations in this line I endeavored to excite tubes,
devoid of any electrodes, by electromagnetic induction, making the tube
the secondary of the induction device, and passing through the primary
the discharges of a Leyden jar. These tubes were made of many shapes,
and I was able to obtain luminous effects which I then thought were due
wholly to electromagnetic induction. But on carefully investigating the
phenomena I found that the effects produced were more of an
electrostatic nature. It may be attributed to this circumstance that
this mode of exciting tubes is very wasteful, namely, the primary
circuit being closed, the potential, and consequently the electrostatic
inductive effect, is much diminished.

When an induction coil, operated as above described, is used, there is
no doubt that the tubes are excited by electrostatic induction, and that
electromagnetic induction has little, if anything, to do with the
phenomena.

[Illustration: FIG. 124.]

This is evident from many experiments. For instance, if a tube be taken
in one hand, the observer being near the coil, it is brilliantly lighted
and remains so no matter in what position it is held relatively to the
observer's body. Were the action electromagnetic, the tube could not be
lighted when the observer's body is interposed between it and the coil,
or at least its luminosity should be considerably diminished. When the
tube is held exactly over the centre of the coil--the latter being wound
in sections and the primary placed symmetrically to the secondary--it
may remain completely dark, whereas it is rendered intensely luminous by
moving it slightly to the right or left from the centre of the coil. It
does not light because in the middle both halves of the coil neutralize
each other, and the electric potential is zero. If the action were
electromagnetic, the tube should light best in the plane through the
centre of the coil, since the electromagnetic effect there should be a
maximum. When an arc is established between the terminals, the tubes and
lamps in the vicinity of the coil go out, but light up again when the
arc is broken, on account of the rise of potential. Yet the
electromagnetic effect should be practically the same in both cases.

By placing a tube at some distance from the coil, and nearer to one
terminal--preferably at a point on the axis of the coil--one may light
it by touching the remote terminal with an insulated body of some size
or with the hand, thereby raising the potential at that terminal nearer
to the tube. If the tube is shifted nearer to the coil so that it is
lighted by the action of the nearer terminal, it may be made to go out
by holding, on an insulated support, the end of a wire connected to the
remote terminal, in the vicinity of the nearer terminal, by this means
counteracting the action of the latter upon the tube. These effects are
evidently electrostatic. Likewise, when a tube is placed at a
considerable distance from the coil, the observer may, standing upon an
insulated support between coil and tube, light the latter by approaching
the hand to it; or he may even render it luminous by simply stepping
between it and the coil. This would be impossible with electro-magnetic
induction, for the body of the observer would act as a screen.

When the coil is energized by excessively weak currents, the
experimenter may, by touching one terminal of the coil with the tube,
extinguish the latter, and may again light it by bringing it out of
contact with the terminal and allowing a small arc to form. This is
clearly due to the respective lowering and raising of the potential at
that terminal. In the above experiment, when the tube is lighted through
a small arc, it may go out when the arc is broken, because the
electrostatic inductive effect alone is too weak, though the potential
may be much higher; but when the arc is established, the electrification
of the end of the tube is much greater, and it consequently lights.

If a tube is lighted by holding it near to the coil, and in the hand
which is remote, by grasping the tube anywhere with the other hand, the
part between the hands is rendered dark, and the singular effect of
wiping out the light of the tube may be produced by passing the hand
quickly along the tube and at the same time withdrawing it gently from
the coil, judging properly the distance so that the tube remains dark
afterwards.

If the primary coil is placed sidewise, as in Fig. 112 B for instance,
and an exhausted tube be introduced from the other side in the hollow
space, the tube is lighted most intensely because of the increased
condenser action, and in this position the striae are most sharply
defined. In all these experiments described, and in many others, the
action is clearly electrostatic.

The effects of screening also indicate the electrostatic nature of the
phenomena and show something of the nature of electrification through
the air. For instance, if a tube is placed in the direction of the axis
of the coil, and an insulated metal plate be interposed, the tube will
generally increase in brilliancy, or if it be too far from the coil to
light, it may even be rendered luminous by interposing an insulated
metal plate. The magnitude of the effects depends to some extent on the
size of the plate. But if the metal plate be connected by a wire to the
ground, its interposition will always make the tube go out even if it be
very near the coil. In general, the interposition of a body between the
coil and tube, increases or diminishes the brilliancy of the tube, or
its facility to light up, according to whether it increases or
diminishes the electrification. When experimenting with an insulated
plate, the plate should not be taken too large, else it will generally
produce a weakening effect by reason of its great facility for giving
off energy to the surroundings.

If a tube be lighted at some distance from the coil, and a plate of hard
rubber or other insulating substance be interposed, the tube may be made
to go out. The interposition of the dielectric in this case only
slightly increases the inductive effect, but diminishes considerably the
electrification through the air.

In all cases, then, when we excite luminosity in exhausted tubes by
means of such a coil, the effect is due to the rapidly alternating
electrostatic potential; and, furthermore, it must be attributed to the
harmonic alternation produced directly by the machine, and not to any
superimposed vibration which might be thought to exist. Such
superimposed vibrations are impossible when we work with an alternate
current machine. If a spring be gradually tightened and released, it
does not perform independent vibrations; for this a sudden release is
necessary. So with the alternate currents from a dynamo machine; the
medium is harmonically strained and released, this giving rise to only
one kind of waves; a sudden contact or break, or a sudden giving way of
the dielectric, as in the disruptive discharge of a Leyden jar, are
essential for the production of superimposed waves.

In all the last described experiments, tubes devoid of any electrodes
may be used, and there is no difficulty in producing by their means
sufficient light to read by. The light effect is, however, considerably
increased by the use of phosphorescent bodies such as yttria, uranium
glass, etc. A difficulty will be found when the phosphorescent material
is used, for with these powerful effects, it is carried gradually away,
and it is preferable to use material in the form of a solid.

Instead of depending on induction at a distance to light the tube, the
same may be provided with an external--and, if desired, also with an
internal--condenser coating, and it may then be suspended anywhere in
the room from a conductor connected to one terminal of the coil, and in
this manner a soft illumination may be provided.

[Illustration: FIG. 125.]

The ideal way of lighting a hall or room would, however, be to produce
such a condition in it that an illuminating device could be moved and
put anywhere, and that it is lighted, no matter where it is put and
without being electrically connected to anything. I have been able to
produce such a condition by creating in the room a powerful, rapidly
alternating electrostatic field. For this purpose I suspend a sheet of
metal a distance from the ceiling on insulating cords and connect it to
one terminal of the induction coil, the other terminal being preferably
connected to the ground. Or else I suspend two sheets as illustrated in
Fig. 125, each sheet being connected with one of the terminals of the
coil, and their size being carefully determined. An exhausted tube may
then be carried in the hand anywhere between the sheets or placed
anywhere, even a certain distance beyond them; it remains always
luminous.

In such an electrostatic field interesting phenomena may be observed,
especially if the alternations are kept low and the potentials
excessively high. In addition to the luminous phenomena mentioned, one
may observe that any insulated conductor gives sparks when the hand or
another object is approached to it, and the sparks may often be
powerful. When a large conducting object is fastened on an insulating
support, and the hand approached to it, a vibration, due to the
rythmical motion of the air molecules is felt, and luminous streams may
be perceived when the hand is held near a pointed projection. When a
telephone receiver is made to touch with one or both of its terminals an
insulated conductor of some size, the telephone emits a loud sound; it
also emits a sound when a length of wire is attached to one or both
terminals, and with very powerful fields a sound may be perceived even
without any wire.

How far this principle is capable of practical application, the future
will tell. It might be thought that electrostatic effects are unsuited
for such action at a distance. Electromagnetic inductive effects, if
available for the production of light, might be thought better suited.
It is true the electrostatic effects diminish nearly with the cube of
the distance from the coil, whereas the electromagnetic inductive
effects diminish simply with the distance. But when we establish an
electrostatic field of force, the condition is very different, for then,
instead of the differential effect of both the terminals, we get their
conjoint effect. Besides, I would call attention to the effect, that in
an alternating electrostatic field, a conductor, such as an exhausted
tube, for instance, tends to take up most of the energy, whereas in an
electromagnetic alternating field the conductor tends to take up the
least energy, the waves being reflected with but little loss. This is
one reason why it is difficult to excite an exhausted tube, at a
distance, by electromagnetic induction. I have wound coils of very large
diameter and of many turns of wire, and connected a Geissler tube to the
ends of the coil with the object of exciting the tube at a distance; but
even with the powerful inductive effects producible by Leyden jar
discharges, the tube could not be excited unless at a very small
distance, although some judgment was used as to the dimensions of the
coil. I have also found that even the most powerful Leyden jar
discharges are capable of exciting only feeble luminous effects in a
closed exhausted tube, and even these effects upon thorough examination
I have been forced to consider of an electrostatic nature.

How then can we hope to produce the required effects at a distance by
means of electromagnetic action, when even in the closest proximity to
the source of disturbance, under the most advantageous conditions, we
can excite but faint luminosity? It is true that when acting at a
distance we have the resonance to help us out. We can connect an
exhausted tube, or whatever the illuminating device may be, with an
insulated system of the proper capacity, and so it may be possible to
increase the effect qualitatively, and only qualitatively, for we would
not get _more_ energy through the device. So we may, by resonance
effect, obtain the required electromotive force in an exhausted tube,
and excite faint luminous effects, but we cannot get enough energy to
render the light practically available, and a simple calculation, based
on experimental results, shows that even if all the energy which a tube
would receive at a certain distance from the source should be wholly
converted into light, it would hardly satisfy the practical
requirements. Hence the necessity of directing, by means of a conducting
circuit, the energy to the place of transformation. But in so doing we
cannot very sensibly depart from present methods, and all we could do
would be to improve the apparatus.

From these considerations it would seem that if this ideal way of
lighting is to be rendered practicable it will be only by the use of
electrostatic effects. In such a case the most powerful electrostatic
inductive effects are needed; the apparatus employed must, therefore, be
capable of producing high electrostatic potentials changing in value
with extreme rapidity. High frequencies are especially wanted, for
practical considerations make it desirable to keep down the potential.
By the employment of machines, or, generally speaking, of any
mechanical apparatus, but low frequencies can be reached; recourse must,
therefore, be had to some other means. The discharge of a condenser
affords us a means of obtaining frequencies by far higher than are
obtainable mechanically, and I have accordingly employed condensers in
the experiments to the above end.

When the terminals of a high tension induction coil, Fig. 126, are
connected to a Leyden jar, and the latter is discharging disruptively
into a circuit, we may look upon the arc playing between the knobs as
being a source of alternating, or generally speaking, undulating
currents, and then we have to deal with the familiar system of a
generator of such currents, a circuit connected to it, and a condenser
bridging the circuit. The condenser in such case is a veritable
transformer, and since the frequency is excessive, almost any ratio in
the strength of the currents in both the branches may be obtained. In
reality the analogy is not quite complete, for in the disruptive
discharge we have most generally a fundamental instantaneous variation
of comparatively low frequency, and a superimposed harmonic vibration,
and the laws governing the flow of currents are not the same for both.

In converting in this manner, the ratio of conversion should not be too
great, for the loss in the arc between the knobs increases with the
square of the current, and if the jar be discharged through very thick
and short conductors, with the view of obtaining a very rapid
oscillation, a very considerable portion of the energy stored is lost.
On the other hand, too small ratios are not practicable for many obvious
reasons.

As the converted currents flow in a practically closed circuit, the
electrostatic effects are necessarily small, and I therefore convert
them into currents or effects of the required character. I have effected
such conversions in several ways. The preferred plan of connections is
illustrated in Fig. 127. The manner of operating renders it easy to
obtain by means of a small and inexpensive apparatus enormous
differences of potential which have been usually obtained by means of
large and expensive coils. For this it is only necessary to take an
ordinary small coil, adjust to it a condenser and discharging circuit,
forming the primary of an auxiliary small coil, and convert upward. As
the inductive effect of the primary currents is excessively great, the
second coil need have comparatively but very few turns. By properly
adjusting the elements, remarkable results may be secured.

In endeavoring to obtain the required electrostatic effects in this
manner, I have, as might be expected, encountered many difficulties
which I have been gradually overcoming, but I am not as yet prepared to
dwell upon my experiences in this direction.

I believe that the disruptive discharge of a condenser will play an
important part in the future, for it offers vast possibilities, not only
in the way of producing light in a more efficient manner and in the line
indicated by theory, but also in many other respects.

[Illustration: FIG. 126.]

For years the efforts of inventors have been directed towards obtaining
electrical energy from heat by means of the thermopile. It might seem
invidious to remark that but few know what is the real trouble with the
thermopile. It is not the inefficiency or small output--though these are
great drawbacks--but the fact that the thermopile has its phylloxera,
that is, that by constant use it is deteriorated, which has thus far
prevented its introduction on an industrial scale. Now that all modern
research seems to point with certainty to the use of electricity of
excessively high tension, the question must present itself to many
whether it is not possible to obtain in a practicable manner this form
of energy from heat. We have been used to look upon an electrostatic
machine as a plaything, and somehow we couple with it the idea of the
inefficient and impractical. But now we must think differently, for now
we know that everywhere we have to deal with the same forces, and that
it is a mere question of inventing proper methods or apparatus for
rendering them available.

In the present systems of electrical distribution, the employment of the
iron with its wonderful magnetic properties allows us to reduce
considerably the size of the apparatus; but, in spite of this, it is
still very cumbersome. The more we progress in the study of electric and
magnetic phenomena, the more we become convinced that the present
methods will be short-lived. For the production of light, at least, such
heavy machinery would seem to be unnecessary. The energy required is
very small, and if light can be obtained as efficiently as,
theoretically, it appears possible, the apparatus need have but a very
small output. There being a strong probability that the illuminating
methods of the future will involve the use of very high potentials, it
seems very desirable to perfect a contrivance capable of converting the
energy of heat into energy of the requisite form. Nothing to speak of
has been done towards this end, for the thought that electricity of some
50,000 or 100,000 volts pressure or more, even if obtained, would be
unavailable for practical purposes, has deterred inventors from working
in this direction.

[Illustration: FIG. 127.]

In Fig. 126 a plan of connections is shown for converting currents of
high, into currents of low, tension by means of the disruptive discharge
of a condenser. This plan has been used by me frequently for operating a
few incandescent lamps required in the laboratory. Some difficulties
have been encountered in the arc of the discharge which I have been able
to overcome to a great extent; besides this, and the adjustment
necessary for the proper working, no other difficulties have been met
with, and it was easy to operate ordinary lamps, and even motors, in
this manner. The line being connected to the ground, all the wires could
be handled with perfect impunity, no matter how high the potential at
the terminals of the condenser. In these experiments a high tension
induction coil, operated from a battery or from an alternate current
machine, was employed to charge the condenser; but the induction coil
might be replaced by an apparatus of a different kind, capable of giving
electricity of such high tension. In this manner, direct or alternating
currents may be converted, and in both cases the current-impulses may be
of any desired frequency. When the currents charging the condenser are
of the same direction, and it is desired that the converted currents
should also be of one direction, the resistance of the discharging
circuit should, of course, be so chosen that there are no oscillations.

[Illustration: FIG. 128.]

In operating devices on the above plan I have observed curious phenomena
of impedance which are of interest. For instance if a thick copper bar
be bent, as indicated in Fig. 128, and shunted by ordinary incandescent
lamps, then, by passing the discharge between the knobs, the lamps may
be brought to incandescence although they are short-circuited. When a
large induction coil is employed it is easy to obtain nodes on the bar,
which are rendered evident by the different degree of brilliancy of the
lamps, as shown roughly in Fig. 128. The nodes are never clearly
defined, but they are simply maxima and minima of potentials along the
bar. This is probably due to the irregularity of the arc between the
knobs. In general when the above-described plan of conversion from high
to low tension is used, the behavior of the disruptive discharge may be
closely studied. The nodes may also be investigated by means of an
ordinary Cardew voltmeter which should be well insulated. Geissler
tubes may also be lighted across the points of the bent bar; in this
case, of course, it is better to employ smaller capacities. I have found
it practicable to light up in this manner a lamp, and even a Geissler
tube, shunted by a short, heavy block of metal, and this result seems at
first very curious. In fact, the thicker the copper bar in Fig. 128, the
better it is for the success of the experiments, as they appear more
striking. When lamps with long slender filaments are used it will be
often noted that the filaments are from time to time violently vibrated,
the vibration being smallest at the nodal points. This vibration seems
to be due to an electrostatic action between the filament and the glass
of the bulb.

[Illustration: FIG. 129.]

In some of the above experiments it is preferable to use special lamps
having a straight filament as shown in Fig. 129. When such a lamp is
used a still more curious phenomenon than those described may be
observed. The lamp may be placed across the copper bar and lighted, and
by using somewhat larger capacities, or, in other words, smaller
frequencies or smaller impulsive impedances, the filament may be brought
to any desired degree of incandescence. But when the impedance is
increased, a point is reached when comparatively little current passes
through the carbon, and most of it through the rarefied gas; or perhaps
it may be more correct to state that the current divides nearly evenly
through both, in spite of the enormous difference in the resistance, and
this would be true unless the gas and the filament behave differently.
It is then noted that the whole bulb is brilliantly illuminated, and the
ends of the leading-in wires become incandescent and often throw off
sparks in consequence of the violent bombardment, but the carbon
filament remains dark. This is illustrated in Fig. 129. Instead of the
filament a single wire extending through the whole bulb may be used,
and in this case the phenomenon would seem to be still more interesting.

From the above experiment it will be evident, that when ordinary lamps
are operated by the converted currents, those should be preferably taken
in which the platinum wires are far apart, and the frequencies used
should not be too great, else the discharge will occur at the ends of
the filament or in the base of the lamp between the leading-in wires,
and the lamp might then be damaged.

In presenting to you these results of my investigation on the subject
under consideration, I have paid only a passing notice to facts upon
which I could have dwelt at length, and among many observations I have
selected only those which I thought most likely to interest you. The
field is wide and completely unexplored, and at every step a new truth
is gleaned, a novel fact observed.

How far the results here borne out are capable of practical applications
will be decided in the future. As regards the production of light, some
results already reached are encouraging and make me confident in
asserting that the practical solution of the problem lies in the
direction I have endeavored to indicate. Still, whatever may be the
immediate outcome of these experiments I am hopeful that they will only
prove a step in further development towards the ideal and final
perfection. The possibilities which are opened by modern research are so
vast that even the most reserved must feel sanguine of the future.
Eminent scientists consider the problem of utilizing one kind of
radiation without the others a rational one. In an apparatus designed
for the production of light by conversion from any form of energy into
that of light, such a result can never be reached, for no matter what
the process of producing the required vibrations, be it electrical,
chemical or any other, it will not be possible to obtain the higher
light vibrations without going through the lower heat vibrations. It is
the problem of imparting to a body a certain velocity without passing
through all lower velocities. But there is a possibility of obtaining
energy not only in the form of light, but motive power, and energy of
any other form, in some more direct way from the medium. The time will
be when this will be accomplished, and the time has come when one may
utter such words before an enlightened audience without being considered
a visionary. We are whirling through endless space with an
inconceivable speed, all around us everything is spinning, everything is
moving, everywhere is energy. There _must_ be some way of availing
ourselves of this energy more directly. Then, with the light obtained
from the medium, with the power derived from it, with every form of
energy obtained without effort, from the store forever inexhaustible,
humanity will advance with giant strides. The mere contemplation of
these magnificent possibilities expands our minds, strengthens our hopes
and fills our hearts with supreme delight.




CHAPTER XXVII.

EXPERIMENTS WITH ALTERNATE CURRENTS OF HIGH POTENTIAL AND HIGH
FREQUENCY.[2]

  [2] Lecture delivered before the Institution of Electrical
      Engineers, London, February, 1892.


I cannot find words to express how deeply I feel the honor of addressing
some of the foremost thinkers of the present time, and so many able
scientific men, engineers and electricians, of the country greatest in
scientific achievements.

The results which I have the honor to present before such a gathering I
cannot call my own. There are among you not a few who can lay better
claim than myself on any feature of merit which this work may contain. I
need not mention many names which are world-known--names of those among
you who are recognized as the leaders in this enchanting science; but
one, at least, I must mention--a name which could not be omitted in a
demonstration of this kind. It is a name associated with the most
beautiful invention ever made: it is Crookes!

When I was at college, a good while ago, I read, in a translation (for
then I was not familiar with your magnificent language), the description
of his experiments on radiant matter. I read it only once in my
life--that time--yet every detail about that charming work I can
remember to this day. Few are the books, let me say, which can make such
an impression upon the mind of a student.

But if, on the present occasion, I mention this name as one of many your
Institution can boast of, it is because I have more than one reason to
do so. For what I have to tell you and to show you this evening
concerns, in a large measure, that same vague world which Professor
Crookes has so ably explored; and, more than this, when I trace back the
mental process which led me to these advances--which even by myself
cannot be considered trifling, since they are so appreciated by you--I
believe that their real origin, that which started me to work in this
direction, and brought me to them, after a long period of constant
thought, was that fascinating little book which I read many years ago.

And now that I have made a feeble effort to express my homage and
acknowledge my indebtedness to him and others among you, I will make a
second effort, which I hope you will not find so feeble as the first, to
entertain you.

Give me leave to introduce the subject in a few words.

A short time ago I had the honor to bring before our American Institute
of Electrical Engineers some results then arrived at by me in a novel
line of work. I need not assure you that the many evidences which I have
received that English scientific men and engineers were interested in
this work have been for me a great reward and encouragement. I will not
dwell upon the experiments already described, except with the view of
completing, or more clearly expressing, some ideas advanced by me
before, and also with the view of rendering the study here presented
self-contained, and my remarks on the subject of this evening's lecture
consistent.

This investigation, then, it goes without saying, deals with alternating
currents, and to be more precise, with alternating currents of high
potential and high frequency. Just in how much a very high frequency is
essential for the production of the results presented is a question
which, even with my present experience, would embarrass me to answer.
Some of the experiments may be performed with low frequencies; but very
high frequencies are desirable, not only on account of the many effects
secured by their use, but also as a convenient means of obtaining, in
the induction apparatus employed, the high potentials, which in their
turn are necessary to the demonstration of most of the experiments here
contemplated.

Of the various branches of electrical investigation, perhaps the most
interesting and the most immediately promising is that dealing with
alternating currents. The progress in this branch of applied science has
been so great in recent years that it justifies the most sanguine hopes.
Hardly have we become familiar with one fact, when novel experiences are
met and new avenues of research are opened. Even at this hour
possibilities not dreamed of before are, by the use of these currents,
partly realized. As in nature all is ebb and tide, all is wave motion,
so it seems that in all branches of industry alternating
currents--electric wave motion--will have the sway.

One reason, perhaps, why this branch of science is being so rapidly
developed is to be found in the interest which is attached to its
experimental study. We wind a simple ring of iron with coils; we
establish the connections to the generator, and with wonder and delight
we note the effects of strange forces which we bring into play, which
allow us to transform, to transmit and direct energy at will. We arrange
the circuits properly, and we see the mass of iron and wires behave as
though it were endowed with life, spinning a heavy armature, through
invisible connections, with great speed and power--with the energy
possibly conveyed from a great distance. We observe how the energy of an
alternating current traversing the wire manifests itself--not so much in
the wire as in the surrounding space--in the most surprising manner,
taking the forms of heat, light, mechanical energy, and, most surprising
of all, even chemical affinity. All these observations fascinate us, and
fill us with an intense desire to know more about the nature of these
phenomena. Each day we go to our work in the hope of discovering,--in
the hope that some one, no matter who, may find a solution of one of the
pending great problems,--and each succeeding day we return to our task
with renewed ardor; and even if we _are_ unsuccessful, our work has not
been in vain, for in these strivings, in these efforts, we have found
hours of untold pleasure, and we have directed our energies to the
benefit of mankind.

We may take--at random, if you choose--any of the many experiments which
may be performed with alternating currents; a few of which only, and by
no means the most striking, form the subject of this evening's
demonstration; they are all equally interesting, equally inciting to
thought.

Here is a simple glass tube from which the air has been partially
exhausted. I take hold of it; I bring my body in contact with a wire
conveying alternating currents of high potential, and the tube in my
hand is brilliantly lighted. In whatever position I may put it, wherever
I move it in space, as far as I can reach, its soft, pleasing light
persists with undiminished brightness.

Here is an exhausted bulb suspended from a single wire. Standing on an
insulated support, I grasp it, and a platinum button mounted in it is
brought to vivid incandescence.

Here, attached to a leading wire, is another bulb, which, as I touch its
metallic socket, is filled with magnificent colors of phosphorescent
light.

Here still another, which by my fingers' touch casts a shadow--the
Crookes shadow--of the stem inside of it.

Here, again, insulated as I stand on this platform, I bring my body in
contact with one of the terminals of the secondary of this induction
coil--with the end of a wire many miles long--and you see streams of
light break forth from its distant end, which is set in violent
vibration.

Here, once more, I attach these two plates of wire gauze to the
terminals of the coil; I set them a distance apart, and I set the coil
to work. You may see a small spark pass between the plates. I insert a
thick plate of one of the best dielectrics between them, and instead of
rendering altogether impossible, as we are used to expect, I _aid_ the
passage of the discharge, which, as I insert the plate, merely changes
in appearance and assumes the form of luminous streams.

Is there, I ask, can there be, a more interesting study than that of
alternating currents?

In all these investigations, in all these experiments, which are so
very, very interesting, for many years past--ever since the greatest
experimenter who lectured in this hall discovered its principle--we have
had a steady companion, an appliance familiar to every one, a plaything
once, a thing of momentous importance now--the induction coil. There is
no dearer appliance to the electrician. From the ablest among you, I
dare say, down to the inexperienced student, to your lecturer, we all
have passed many delightful hours in experimenting with the induction
coil. We have watched its play, and thought and pondered over the
beautiful phenomena which it disclosed to our ravished eyes. So well
known is this apparatus, so familiar are these phenomena to every one,
that my courage nearly fails me when I think that I have ventured to
address so able an audience, that I have ventured to entertain you with
that same old subject. Here in reality is the same apparatus, and here
are the same phenomena, only the apparatus is operated somewhat
differently, the phenomena are presented in a different aspect. Some of
the results we find as expected, others surprise us, but all captivate
our attention, for in scientific investigation each novel result
achieved may be the centre of a new departure, each novel fact learned
may lead to important developments.

Usually in operating an induction coil we have set up a vibration of
moderate frequency in the primary, either by means of an interrupter or
break, or by the use of an alternator. Earlier English investigators, to
mention only Spottiswoode and J. E. H. Gordon, have used a rapid break
in connection with the coil. Our knowledge and experience of to-day
enables us to see clearly why these coils under the conditions of the
test did not disclose any remarkable phenomena, and why able
experimenters failed to perceive many of the curious effects which have
since been observed.

In the experiments such as performed this evening, we operate the coil
either from a specially constructed alternator capable of giving many
thousands of reversals of current per second, or, by disruptively
discharging a condenser through the primary, we set up a vibration in
the secondary circuit of a frequency of many hundred thousand or
millions per second, if we so desire; and in using either of these means
we enter a field as yet unexplored.

It is impossible to pursue an investigation in any novel line without
finally making some interesting observation or learning some useful
fact. That this statement is applicable to the subject of this lecture
the many curious and unexpected phenomena which we observe afford a
convincing proof. By way of illustration, take for instance the most
obvious phenomena, those of the discharge of the induction coil.

Here is a coil which is operated by currents vibrating with extreme
rapidity, obtained by disruptively discharging a Leyden jar. It would
not surprise a student were the lecturer to say that the secondary of
this coil consists of a small length of comparatively stout wire; it
would not surprise him were the lecturer to state that, in spite of
this, the coil is capable of giving any potential which the best
insulation of the turns is able to withstand; but although he may be
prepared, and even be indifferent as to the anticipated result, yet the
aspect of the discharge of the coil will surprise and interest him.
Every one is familiar with the discharge of an ordinary coil; it need
not be reproduced here. But, by way of contrast, here is a form of
discharge of a coil, the primary current of which is vibrating several
hundred thousand times per second. The discharge of an ordinary coil
appears as a simple line or band of light. The discharge of this coil
appears in the form of powerful brushes and luminous streams issuing
from all points of the two straight wires attached to the terminals of
the secondary. (Fig. 130.)

[Illustration: FIG. 130.]

[Illustration: FIG. 131.]

Now compare this phenomenon which you have just witnessed with the
discharge of a Holtz or Wimshurst machine--that other interesting
appliance so dear to the experimenter. What a difference there is
between these phenomena! And yet, had I made the necessary
arrangements--which could have been made easily, were it not that they
would interfere with other experiments--I could have produced with this
coil sparks which, had I the coil hidden from your view and only two
knobs exposed, even the keenest observer among you would find it
difficult, if not impossible, to distinguish from those of an influence
or friction machine. This may be done in many ways--for instance, by
operating the induction coil which charges the condenser from an
alternating-current machine of very low frequency, and preferably
adjusting the discharge circuit so that there are no oscillations set up
in it. We then obtain in the secondary circuit, if the knobs are of the
required size and properly set, a more or less rapid succession of
sparks of great intensity and small quantity, which possess the same
brilliancy, and are accompanied by the same sharp crackling sound, as
those obtained from a friction or influence machine.

Another way is to pass through two primary circuits, having a common
secondary, two currents of a slightly different period, which produce in
the secondary circuit sparks occurring at comparatively long intervals.
But, even with the means at hand this evening, I may succeed in
imitating the spark of a Holtz machine. For this purpose I establish
between the terminals of the coil which charges the condenser a long,
unsteady arc, which is periodically interrupted by the upward current of
air produced by it. To increase the current of air I place on each side
of the arc, and close to it, a large plate of mica. The condenser
charged from this coil discharges into the primary circuit of a second
coil through a small air gap, which is necessary to produce a sudden
rush of current through the primary. The scheme of connections in the
present experiment is indicated in Fig. 131.

G is an ordinarily constructed alternator, supplying the primary P of an
induction coil, the secondary S of which charges the condensers or jars
C C. The terminals of the secondary are connected to the inside coatings
of the jars, the outer coatings being connected to the ends of the
primary _p p_ of a second induction coil. This primary _p p_ has a small
air gap _a b_.

The secondary _s_ of this coil is provided with knobs or spheres K K of
the proper size and set at a distance suitable for the experiment.

A long arc is established between the terminals A B of the first
induction coil. M M are the mica plates.

Each time the arc is broken between A and B the jars are quickly charged
and discharged through the primary _p p_, producing a snapping spark
between the knobs K K. Upon the arc forming between A and B the
potential falls, and the jars cannot be charged to such high potential
as to break through the air gap _a b_ until the arc is again broken by
the draught.

In this manner sudden impulses, at long intervals, are produced in the
primary _p p_, which in the secondary _s_ give a corresponding number of
impulses of great intensity. If the secondary knobs or spheres, K K, are
of the proper size, the sparks show much resemblance to those of a Holtz
machine.

But these two effects, which to the eye appear so very different, are
only two of the many discharge phenomena. We only need to change the
conditions of the test, and again we make other observations of
interest.

When, instead of operating the induction coil as in the last two
experiments, we operate it from a high frequency alternator, as in the
next experiment, a systematic study of the phenomena is rendered much
more easy. In such case, in varying the strength and frequency of the
currents through the primary, we may observe five distinct forms of
discharge, which I have described in my former paper on the subject
before the American Institute of Electrical Engineers, May 20, 1891.

It would take too much time, and it would lead us too far from the
subject presented this evening, to reproduce all these forms, but it
seems to me desirable to show you one of them. It is a brush discharge,
which is interesting in more than one respect. Viewed from a near
position it resembles much a jet of gas escaping under great pressure.
We know that the phenomenon is due to the agitation of the molecules
near the terminal, and we anticipate that some heat must be developed by
the impact of the molecules against the terminal or against each other.
Indeed, we find that the brush is hot, and only a little thought leads
us to the conclusion that, could we but reach sufficiently high
frequencies, we could produce a brush which would give intense light and
heat, and which would resemble in every particular an ordinary flame,
save, perhaps, that both phenomena might not be due to the same
agent--save, perhaps, that chemical affinity might not be _electrical_
in its nature.

As the production of heat and light is here due to the impact of the
molecules, or atoms of air, or something else besides, and, as we can
augment the energy simply by raising the potential, we might, even with
frequencies obtained from a dynamo machine, intensify the action to such
a degree as to bring the terminal to melting heat. But with such low
frequencies we would have to deal always with something of the nature of
an electric current. If I approach a conducting object to the brush, a
thin little spark passes, yet, even with the frequencies used this
evening, the tendency to spark is not very great. So, for instance, if I
hold a metallic sphere at some distance above the terminal, you may see
the whole space between the terminal and sphere illuminated by the
streams without the spark passing; and with the much higher frequencies
obtainable by the disruptive discharge of a condenser, were it not for
the sudden impulses, which are comparatively few in number, sparking
would not occur even at very small distances. However, with incomparably
higher frequencies, which we may yet find means to produce efficiently,
and provided that electric impulses of such high frequencies could be
transmitted through a conductor, the electrical characteristics of the
brush discharge would completely vanish--no spark would pass, no shock
would be felt--yet we would still have to deal with an _electric_
phenomenon, but in the broad, modern interpretation of the word. In my
first paper, before referred to, I have pointed out the curious
properties of the brush, and described the best manner of producing it,
but I have thought it worth while to endeavor to express myself more
clearly in regard to this phenomenon, because of its absorbing interest.

When a coil is operated with currents of very high frequency, beautiful
brush effects may be produced, even if the coil be of comparatively
small dimensions. The experimenter may vary them in many ways, and, if
it were for nothing else, they afford a pleasing sight. What adds to
their interest is that they may be produced with one single terminal as
well as with two--in fact, often better with one than with two.

But of all the discharge phenomena observed, the most pleasing to the
eye, and the most instructive, are those observed with a coil which is
operated by means of the disruptive discharge of a condenser. The power
of the brushes, the abundance of the sparks, when the conditions are
patiently adjusted, is often amazing. With even a very small coil, if it
be so well insulated as to stand a difference of potential of several
thousand volts per turn, the sparks may be so abundant that the whole
coil may appear a complete mass of fire.

Curiously enough the sparks, when the terminals of the coil are set at a
considerable distance, seem to dart in every possible direction as
though the terminals were perfectly independent of each other. As the
sparks would soon destroy the insulation, it is necessary to prevent
them. This is best done by immersing the coil in a good liquid
insulator, such as boiled-out oil. Immersion in a liquid may be
considered almost an absolute necessity for the continued and successful
working of such a coil.

It is, of course, out of the question, in an experimental lecture, with
only a few minutes at disposal for the performance of each experiment,
to show these discharge phenomena to advantage, as, to produce each
phenomenon at its best, a very careful adjustment is required. But even
if imperfectly produced, as they are likely to be this evening, they are
sufficiently striking to interest an intelligent audience.

Before showing some of these curious effects I must, for the sake of
completeness, give a short description of the coil and other apparatus
used in the experiments with the disruptive discharge this evening.

[Illustration: FIG. 132.]

It is contained in a box B (Fig. 132) of thick boards of hard wood,
covered on the outside with a zinc sheet Z, which is carefully soldered
all around. It might be advisable, in a strictly scientific
investigation, when accuracy is of great importance, to do away with the
metal cover, as it might introduce many errors, principally on account
of its complex action upon the coil, as a condenser of very small
capacity and as an electrostatic and electromagnetic screen. When the
coil is used for such experiments as are here contemplated, the
employment of the metal cover offers some practical advantages, but
these are not of sufficient importance to be dwelt upon.

The coil should be placed symmetrically to the metal cover, and the
space between should, of course, not be too small, certainly not less
than, say, five centimetres, but much more if possible; especially the
two sides of the zinc box, which are at right angles to the axis of the
coil, should be sufficiently remote from the latter, as otherwise they
might impair its action and be a source of loss.

The coil consists of two spools of hard rubber R R, held apart at a
distance of 10 centimetres by bolts C and nuts _n_, likewise of hard
rubber. Each spool comprises a tube T of approximately 8 centimetres
inside diameter, and 3 millimetres thick, upon which are screwed two
flanges F F, 24 centimetres square, the space between the flanges being
about 3 centimetres. The secondary, S S, of the best gutta
percha-covered wire, has 26 layers, 10 turns in each, giving for each
half a total of 260 turns. The two halves are wound oppositely and
connected in series, the connection between both being made over the
primary. This disposition, besides being convenient, has the advantage
that when the coil is well balanced--that is, when both of its
terminals T_{1}, T_{1}, are connected to bodies or devices of equal
capacity--there is not much danger of breaking through to the primary,
and the insulation between the primary and the secondary need not be
thick. In using the coil it is advisable to attach to _both_ terminals
devices of nearly equal capacity, as, when the capacity of the terminals
is not equal, sparks will be apt to pass to the primary. To avoid this,
the middle point of the secondary may be connected to the primary, but
this is not always practicable.

The primary P P is wound in two parts, and oppositely, upon a wooden
spool w, and the four ends are led out of the oil through hard rubber
tubes _t t_. The ends of the secondary T_{1} T_{1}, are also led out of
the oil through rubber tubes t_{1} t_{1} of great thickness. The
primary and secondary layers are insulated by cotton cloth, the
thickness of the insulation, of course, bearing some proportion to the
difference of potential between the turns of the different layers. Each
half of the primary has four layers, 24 turns in each, this giving a
total of 96 turns. When both the parts are connected in series, this
gives a ratio of conversion of about 1:2.7, and with the primaries in
multiple, 1:5.4; but in operating with very rapidly alternating currents
this ratio does not convey even an approximate idea of the ratio of the
E. M. F's. in the primary and secondary circuits. The coil is held in
position in the oil on wooden supports, there being about 5 centimetres
thickness of oil all round. Where the oil is not specially needed, the
space is filled with pieces of wood, and for this purpose principally
the wooden box B surrounding the whole is used.

The construction here shown is, of course, not the best on general
principles, but I believe it is a good and convenient one for the
production of effects in which an excessive potential and a very small
current are needed.

In connection with the coil I use either the ordinary form of discharger
or a modified form. In the former I have introduced two changes which
secure some advantages, and which are obvious. If they are mentioned, it
is only in the hope that some experimenter may find them of use.

One of the changes is that the adjustable knobs A and B (Fig. 133), of
the discharger are held in jaws of brass, J J, by spring pressure, this
allowing of turning them successively into different positions, and so
doing away with the tedious process of frequent polishing up.

[Illustration: FIG. 133.]

The other change consists in the employment of a strong electromagnet
N S, which is placed with its axis at right angles to the line joining
the knobs A and B, and produces a strong magnetic field between them.
The pole pieces of the magnet are movable and properly formed so as to
protrude between the brass knobs, in order to make the field as intense
as possible; but to prevent the discharge from jumping to the magnet the
pole pieces are protected by a layer of mica, M M, of sufficient
thickness; s_{1} s_{1} and s_{2} s_{2} are screws for fastening the
wires. On each side one of the screws is for large and the other for
small wires. L L are screws for fixing in position the rods R R, which
support the knobs.

In another arrangement with the magnet I take the discharge between the
rounded pole pieces themselves, which in such case are insulated and
preferably provided with polished brass caps.

The employment of an intense magnetic field is of advantage principally
when the induction coil or transformer which charges the condenser is
operated by currents of very low frequency. In such a case the number of
the fundamental discharges between the knobs may be so small as to
render the currents produced in the secondary unsuitable for many
experiments. The intense magnetic field then serves to blow out the arc
between the knobs as soon as it is formed, and the fundamental
discharges occur in quicker succession.

[Illustration: FIG. 134.]

Instead of the magnet, a draught or blast of air may be employed with
some advantage. In this case the arc is preferably established between
the knobs A B, in Fig. 131 (the knobs _a b_ being generally joined, or
entirely done away with), as in this disposition the arc is long and
unsteady, and is easily affected by the draught.

When a magnet is employed to break the arc, it is better to choose the
connection indicated diagrammatically in Fig. 134, as in this case the
currents forming the arc are much more powerful, and the magnetic field
exercises a greater influence. The use of the magnet permits, however,
of the arc being replaced by a vacuum tube, but I have encountered great
difficulties in working with an exhausted tube.

The other form of discharger used in these and similar experiments is
indicated in Figs. 135 and 136. It consists of a number of brass pieces
_c c_ (Fig. 135), each of which comprises a spherical middle portion _m_
with an extension _e_ below--which is merely used to fasten the piece in
a lathe when polishing up the discharging surface--and a column above,
which consists of a knurled flange _f_ surmounted by a threaded stem _l_
carrying a nut _n_, by means of which a wire is fastened to the column.
The flange _f_ conveniently serves for holding the brass piece when
fastening the wire, and also for turning it in any position when it
becomes necessary to present a fresh discharging surface. Two stout
strips of hard rubber R R, with planed grooves _g g_ (Fig. 136) to fit
the middle portion of the pieces _c c_, serve to clamp the latter and
hold them firmly in position by means of two bolts C C (of which only
one is shown) passing through the ends of the strips.

[Illustration: FIG. 135.]

[Illustration: FIG. 136.]

In the use of this kind of discharger I have found three principal
advantages over the ordinary form. First, the dielectric strength of a
given total width of air space is greater when a great many small air
gaps are used instead of one, which permits of working with a smaller
length of air gap, and that means smaller loss and less deterioration of
the metal; secondly, by reason of splitting the arc up into smaller
arcs, the polished surfaces are made to last much longer; and, thirdly,
the apparatus affords some gauge in the experiments. I usually set the
pieces by putting between them sheets of uniform thickness at a certain
very small distance which is known from the experiments of Sir William
Thomson to require a certain electromotive force to be bridged by the
spark.

It should, of course, be remembered that the sparking distance is much
diminished as the frequency is increased. By taking any number of spaces
the experimenter has a rough idea of the electromotive force, and he
finds it easier to repeat an experiment, as he has not the trouble of
setting the knobs again and again. With this kind of discharger I have
been able to maintain an oscillating motion without any spark being
visible with the naked eye between the knobs, and they would not show a
very appreciable rise in temperature. This form of discharge also lends
itself to many arrangements of condensers and circuits which are often
very convenient and time-saving. I have used it preferably in a
disposition similar to that indicated in Fig. 131, when the currents
forming the arc are small.

I may here mention that I have also used dischargers with single or
multiple air gaps, in which the discharge surfaces were rotated with
great speed. No particular advantage was, however, gained by this
method, except in cases where the currents from the condenser were large
and the keeping cool of the surfaces was necessary, and in cases when,
the discharge not being oscillating of itself, the arc as soon as
established was broken by the air current, thus starting the vibration
at intervals in rapid succession. I have also used mechanical
interrupters in many ways. To avoid the difficulties with frictional
contacts, the preferred plan adopted was to establish the arc and rotate
through it at great speed a rim of mica provided with many holes and
fastened to a steel plate. It is understood, of course, that the
employment of a magnet, air current, or other interrupter, produces no
effect worth noticing, unless the self-induction, capacity and
resistance are so related that there are oscillations set up upon each
interruption.

I will now endeavor to show you some of the most noteworthy of these
discharge phenomena.

I have stretched across the room two ordinary cotton covered wires, each
about seven metres in length. They are supported on insulating cords at
a distance of about thirty centimetres. I attach now to each of the
terminals of the coil one of the wires, and set the coil in action.
Upon turning the lights off in the room you see the wires strongly
illuminated by the streams issuing abundantly from their whole surface
in spite of the cotton covering, which may even be very thick. When the
experiment is performed under good conditions, the light from the wires
is sufficiently intense to allow distinguishing the objects in a room.
To produce the best result it is, of course, necessary to adjust
carefully the capacity of the jars, the arc between the knobs and the
length of the wires. My experience is that calculation of the length of
the wires leads, in such case, to no result whatever. The experimenter
will do best to take the wires at the start very long, and then adjust
by cutting off first long pieces, and then smaller and smaller ones as
he approaches the right length.

A convenient way is to use an oil condenser of very small capacity,
consisting of two small adjustable metal plates, in connection with this
and similar experiments. In such case I take wires rather short and at
the beginning set the condenser plates at maximum distance. If the
streams from the wires increase by approach of the plates, the length of
the wires is about right; if they diminish, the wires are too long for
that frequency and potential. When a condenser is used in connection
with experiments with such a coil, it should be an oil condenser by all
means, as in using an air condenser considerable energy might be wasted.
The wires leading to the plates in the oil should be very thin, heavily
coated with some insulating compound, and provided with a conducting
covering--this preferably extending under the surface of the oil. The
conducting cover should not be too near the terminals, or ends, of the
wire, as a spark would be apt to jump from the wire to it. The
conducting coating is used to diminish the air losses, in virtue of its
action as an electrostatic screen. As to the size of the vessel
containing the oil, and the size of the plates, the experimenter gains
at once an idea from a rough trial. The size of the plates _in oil_ is,
however, calculable, as the dielectric losses are very small.

In the preceding experiment it is of considerable interest to know what
relation the quantity of the light emitted bears to the frequency and
potential of the electric impulses. My opinion is that the heat as well
as light effects produced should be proportionate, under otherwise equal
conditions of test, to the product of frequency and square of potential,
but the experimental verification of the law, whatever it may be, would
be exceedingly difficult. One thing is certain, at any rate, and that
is, that in augmenting the potential and frequency we rapidly intensify
the streams; and, though it may be very sanguine, it is surely not
altogether hopeless to expect that we may succeed in producing a
practical illuminant on these lines. We would then be simply using
burners or flames, in which there would be no chemical process, no
consumption of material, but merely a transfer of energy, and which
would, in all probability, emit more light and less heat than ordinary
flames.

[Illustration: FIG. 137.]

The luminous intensity of the streams is, of course, considerably
increased when they are focused upon a small surface. This may be shown
by the following experiment:

I attach to one of the terminals of the coil a wire _w_ (Fig. 137), bent
in a circle of about 30 centimetres in diameter, and to the other
terminal I fasten a small brass sphere _s_, the surface of the wire
being preferably equal to the surface of the sphere, and the centre of
the latter being in a line at right angles to the plane of the wire
circle and passing through its centre. When the discharge is established
under proper conditions, a luminous hollow cone is formed, and in the
dark one-half of the brass sphere is strongly illuminated, as shown in
the cut.

By some artifice or other it is easy to concentrate the streams upon
small surfaces and to produce very strong light effects. Two thin wires
may thus be rendered intensely luminous.

In order to intensify the streams the wires should be very thin and
short; but as in this case their capacity would be generally too small
for the coil--at least for such a one as the present--it is necessary to
augment the capacity to the required value, while, at the same time, the
surface of the wires remains very small. This may be done in many ways.

[Illustration: FIG. 138.]

Here, for instance, I have two plates, R R, of hard rubber (Fig. 138),
upon which I have glued two very thin wires _w w_, so as to form a name.
The wires may be bare or covered with the best insulation--it is
immaterial for the success of the experiment. Well insulated wires, if
anything, are preferable. On the back of each plate, indicated by the
shaded portion, is a tinfoil coating _t t_. The plates are placed in
line at a sufficient distance to prevent a spark passing from one wire
to the other. The two tinfoil coatings I have joined by a conductor C,
and the two wires I presently connect to the terminals of the coil. It
is now easy, by varying the strength and frequency of the currents
through the primary, to find a point at which the capacity of the system
is best suited to the conditions, and the wires become so strongly
luminous that, when the light in the room is turned off the name formed
by them appears in brilliant letters.

It is perhaps preferable to perform this experiment with a coil operated
from an alternator of high frequency, as then, owing to the harmonic
rise and fall, the streams are very uniform, though they are less
abundant than when produced with such a coil as the present one. This
experiment, however, may be performed with low frequencies, but much
less satisfactorily.

[Illustration: FIG. 139.]

When two wires, attached to the terminals of the coil, are set at the
proper distance, the streams between them may be so intense as to
produce a continuous luminous sheet. To show this phenomenon I have here
two circles, C and _c_ (Fig. 139), of rather stout wire, one being about
80 centimetres and the other 30 centimetres in diameter. To each of the
terminals of the coil I attach one of the circles. The supporting wires
are so bent that the circles may be placed in the same plane, coinciding
as nearly as possible. When the light in the room is turned off and the
coil set to work, you see the whole space between the wires uniformly
filled with streams, forming a luminous disc, which could be seen from a
considerable distance, such is the intensity of the streams. The outer
circle could have been much larger than the present one; in fact, with
this coil I have used much larger circles, and I have been able to
produce a strongly luminous sheet, covering an area of more than one
square metre, which is a remarkable effect with this very small coil. To
avoid uncertainty, the circle has been taken smaller, and the area is
now about 0.43 square metre.

The frequency of the vibration, and the quickness of succession of the
sparks between the knobs, affect to a marked degree the appearance of
the streams. When the frequency is very low, the air gives way in more
or less the same manner, as by a steady difference of potential, and the
streams consist of distinct threads, generally mingled with thin sparks,
which probably correspond to the successive discharges occurring between
the knobs. But when the frequency is extremely high, and the arc of the
discharge produces a very _loud_ and _smooth_ sound--showing both that
oscillation takes place and that the sparks succeed each other with
great rapidity--then the luminous streams formed are perfectly uniform.
To reach this result very small coils and jars of small capacity should
be used. I take two tubes of thick Bohemian glass, about 5 centimetres
in diameter and 20 centimetres long. In each of the tubes I slip a
primary of very thick copper wire. On the top of each tube I wind a
secondary of much thinner gutta-percha covered wire. The two secondaries
I connect in series, the primaries preferably in multiple arc. The tubes
are then placed in a large glass vessel, at a distance of 10 to 15
centimetres from each other, on insulating supports, and the vessel is
filled with boiled-out oil, the oil reaching about an inch above the
tubes. The free ends of the secondary are lifted out of the coil and
placed parallel to each other at a distance of about ten centimetres.
The ends which are scraped should be dipped in the oil. Two four-pint
jars joined in series may be used to discharge through the primary. When
the necessary adjustments in the length and distance of the wires above
the oil and in the arc of discharge are made, a luminous sheet is
produced between the wires which is perfectly smooth and textureless,
like the ordinary discharge through a moderately exhausted tube.

I have purposely dwelt upon this apparently insignificant experiment. In
trials of this kind the experimenter arrives at the startling conclusion
that, to pass ordinary luminous discharges through gases, no particular
degree of exhaustion is needed, but that the gas may be at ordinary or
even greater pressure. To accomplish this, a very high frequency is
essential; a high potential is likewise required, but this is merely an
incidental necessity. These experiments teach us that, in endeavoring to
discover novel methods of producing light by the agitation of atoms, or
molecules, of a gas, we need not limit our research to the vacuum tube,
but may look forward quite seriously to the possibility of obtaining the
light effects without the use of any vessel whatever, with air at
ordinary pressure.

Such discharges of very high frequency, which render luminous the air at
ordinary pressures, we have probably occasion often to witness in
Nature. I have no doubt that if, as many believe, the aurora borealis is
produced by sudden cosmic disturbances, such as eruptions at the sun's
surface, which set the electrostatic charge of the earth in an extremely
rapid vibration, the red glow observed is not confined to the upper
rarefied strata of the air, but the discharge traverses, by reason of
its very high frequency, also the dense atmosphere in the form of a
_glow_, such as we ordinarily produce in a slightly exhausted tube. If
the frequency were very low, or even more so, if the charge were not at
all vibrating, the dense air would break down as in a lightning
discharge. Indications of such breaking down of the lower dense strata
of the air have been repeatedly observed at the occurrence of this
marvelous phenomenon; but if it does occur, it can only be attributed to
the fundamental disturbances, which are few in number, for the vibration
produced by them would be far too rapid to allow a disruptive break. It
is the original and irregular impulses which affect the instruments; the
superimposed vibrations probably pass unnoticed.

When an ordinary low frequency discharge is passed through moderately
rarefied air, the air assumes a purplish hue. If by some means or other
we increase the intensity of the molecular, or atomic, vibration, the
gas changes to a white color. A similar change occurs at ordinary
pressures with electric impulses of very high frequency. If the
molecules of the air around a wire are moderately agitated, the brush
formed is reddish or violet; if the vibration is rendered sufficiently
intense, the streams become white. We may accomplish this in various
ways. In the experiment before shown with the two wires across the room,
I have endeavored to secure the result by pushing to a high value both
the frequency and potential; in the experiment with the thin wires glued
on the rubber plate I have concentrated the action upon a very small
surface--in other words, I have worked with a great electric density.

[Illustration: FIG. 140.]

A most curious form of discharge is observed with such a coil when the
frequency and potential are pushed to the extreme limit. To perform the
experiment, every part of the coil should be heavily insulated, and only
two small spheres--or, better still, two sharp-edged metal discs (_d d_,
Fig. 140) of no more than a few centimetres in diameter--should be
exposed to the air. The coil here used is immersed in oil, and the ends
of the secondary reaching out of the oil are covered with an air-tight
cover of hard rubber of great thickness. All cracks, if there are any,
should be carefully stopped up, so that the brush discharge cannot form
anywhere except on the small spheres or plates which are exposed to the
air. In this case, since there are no large plates or other bodies of
capacity attached to the terminals, the coil is capable of an extremely
rapid vibration. The potential may be raised by increasing, as far as
the experimenter judges proper, the rate of change of the primary
current. With a coil not widely differing from the present, it is best
to connect the two primaries in multiple arc; but if the secondary
should have a much greater number of turns the primaries should
preferably be used in series, as otherwise the vibration might be too
fast for the secondary. It occurs under these conditions that misty
white streams break forth from the edges of the discs and spread out
phantom-like into space. With this coil, when fairly well produced, they
are about 25 to 30 centimetres long. When the hand is held against them
no sensation is produced, and a spark, causing a shock, jumps from the
terminal only upon the hand being brought much nearer. If the
oscillation of the primary current is rendered intermittent by some
means or other, there is a corresponding throbbing of the streams, and
now the hand or other conducting object may be brought in still greater
proximity to the terminal without a spark being caused to jump.

Among the many beautiful phenomena which may be produced with such a
coil, I have here selected only those which appear to possess some
features of novelty, and lead us to some conclusions of interest. One
will not find it at all difficult to produce in the laboratory, by means
of it, many other phenomena which appeal to the eye even more than these
here shown, but present no particular feature of novelty.

Early experimenters describe the display of sparks produced by an
ordinary large induction coil upon an insulating plate separating the
terminals. Quite recently Siemens performed some experiments in which
fine effects were obtained, which were seen by many with interest. No
doubt large coils, even if operated with currents of low frequencies,
are capable of producing beautiful effects. But the largest coil ever
made could not, by far, equal the magnificent display of streams and
sparks obtained from such a disruptive discharge coil when properly
adjusted. To give an idea, a coil such as the present one will cover
easily a plate of one metre in diameter completely with the streams. The
best way to perform such experiments is to take a very thin rubber or a
glass plate and glue on one side of it a narrow ring of tinfoil of very
large diameter, and on the other a circular washer, the centre of the
latter coinciding with that of the ring, and the surfaces of both being
preferably equal, so as to keep the coil well balanced. The washer and
ring should be connected to the terminals by heavily insulated thin
wires. It is easy in observing the effect of the capacity to produce a
sheet of uniform streams, or a fine network of thin silvery threads, or
a mass of loud brilliant sparks, which completely cover the plate.

Since I have advanced the idea of the conversion by means of the
disruptive discharge, in my paper before the American Institute of
Electrical Engineers at the beginning of the past year, the interest
excited in it has been considerable. It affords us a means for producing
any potentials by the aid of inexpensive coils operated from ordinary
systems of distribution, and--what is perhaps more appreciated--it
enables us to convert currents of any frequency into currents of any
other lower or higher frequency. But its chief value will perhaps be
found in the help which it will afford us in the investigations of the
phenomena of phosphorescence, which a disruptive discharge coil is
capable of exciting in innumerable cases where ordinary coils, even the
largest, would utterly fail.

Considering its probable uses for many practical purposes, and its
possible introduction into laboratories for scientific research, a few
additional remarks as to the construction of such a coil will perhaps
not be found superfluous.

It is, of course, absolutely necessary to employ in such a coil wires
provided with the best insulation.

Good coils may be produced by employing wires covered with several
layers of cotton, boiling the coil a long time in pure wax, and cooling
under moderate pressure. The advantage of such a coil is that it can be
easily handled, but it cannot probably give as satisfactory results as a
coil immersed in pure oil. Besides, it seems that the presence of a
large body of wax affects the coil disadvantageously, whereas this does
not seem to be the case with oil. Perhaps it is because the dielectric
losses in the liquid are smaller.

I have tried at first silk and cotton covered wires with oil immersions,
but I have been gradually led to use gutta-percha covered wires, which
proved most satisfactory. Gutta-percha insulation adds, of course, to
the capacity of the coil, and this, especially if the coil be large, is
a great disadvantage when extreme frequencies are desired; but, on the
other hand, gutta-percha will withstand much more than an equal
thickness of oil, and this advantage should be secured at any price.
Once the coil has been immersed, it should never be taken out of the oil
for more than a few hours, else the gutta-percha will crack up and the
coil will not be worth half as much as before. Gutta-percha is probably
slowly attacked by the oil, but after an immersion of eight to nine
months I have found no ill effects.

I have obtained two kinds of gutta-percha wire known in commerce: in one
the insulation sticks tightly to the metal, in the other it does not.
Unless a special method is followed to expel all air, it is much safer
to use the first kind. I wind the coil within an oil tank so that all
interstices are filled up with the oil. Between the layers I use cloth
boiled out thoroughly in oil, calculating the thickness according to the
difference of potential between the turns. There seems not to be a very
great difference whatever kind of oil is used; I use paraffine or
linseed oil.

To exclude more perfectly the air, an excellent way to proceed, and
easily practicable with small coils, is the following: Construct a box
of hardwood of very thick boards which have been for a long time boiled
in oil. The boards should be so joined as to safely withstand the
external air pressure. The coil being placed and fastened in position
within the box, the latter is closed with a strong lid, and covered with
closely fitting metal sheets, the joints of which are soldered very
carefully. On the top two small holes are drilled, passing through the
metal sheet and the wood, and in these holes two small glass tubes are
inserted and the joints made air-tight. One of the tubes is connected to
a vacuum pump, and the other with a vessel containing a sufficient
quantity of boiled-out oil. The latter tube has a very small hole at the
bottom, and is provided with a stopcock. When a fairly good vacuum has
been obtained, the stopcock is opened and the oil slowly fed in.
Proceeding in this manner, it is impossible that any big bubbles, which
are the principal danger, should remain between the turns. The air is
most completely excluded, probably better than by boiling out, which,
however, when gutta-percha coated wires are used, is not practicable.

For the primaries I use ordinary line wire with a thick cotton coating.
Strands of very thin insulated wires properly interlaced would, of
course, be the best to employ for the primaries, but they are not to be
had.

In an experimental coil the size of the wires is not of great
importance. In the coil here used the primary is No. 12 and the
secondary No. 24 Brown & Sharpe gauge wire; but the sections may be
varied considerably. It would only imply different adjustments; the
results aimed at would not be materially affected.

I have dwelt at some length upon the various forms of brush discharge
because, in studying them, we not only observe phenomena which please
our eye, but also afford us food for thought, and lead us to conclusions
of practical importance. In the use of alternating currents of very high
tension, too much precaution cannot be taken to prevent the brush
discharge. In a main conveying such currents, in an induction coil or
transformer, or in a condenser, the brush discharge is a source of great
danger to the insulation. In a condenser, especially, the gaseous matter
must be most carefully expelled, for in it the charged surfaces are
near each other, and if the potentials are high, just as sure as a
weight will fall if let go, so the insulation will give way if a single
gaseous bubble of some size be present, whereas, if all gaseous matter
were carefully excluded, the condenser would safely withstand a much
higher difference of potential. A main conveying alternating currents of
very high tension may be injured merely by a blow hole or small crack in
the insulation, the more so as a blowhole is apt to contain gas at low
pressure; and as it appears almost impossible to completely obviate such
little imperfections, I am led to believe that in our future
distribution of electrical energy by currents of very high tension,
liquid insulation will be used. The cost is a great drawback, but if we
employ an oil as an insulator the distribution of electrical energy with
something like 100,000 volts, and even more, becomes, at least with
higher frequencies, so easy that it could be hardly called an
engineering feat. With oil insulation and alternate current motors,
transmissions of power can be affected with safety and upon an
industrial basis at distances of as much as a thousand miles.

A peculiar property of oils, and liquid insulation in general, when
subjected to rapidly changing electric stresses, is to disperse any
gaseous bubbles which may be present, and diffuse them through its mass,
generally long before any injurious break can occur. This feature may be
easily observed with an ordinary induction coil by taking the primary
out, plugging up the end of the tube upon which the secondary is wound,
and filling it with some fairly transparent insulator, such as paraffine
oil. A primary of a diameter something like six millimetres smaller than
the inside of the tube may be inserted in the oil. When the coil is set
to work one may see, looking from the top through the oil, many luminous
points--air bubbles which are caught by inserting the primary, and which
are rendered luminous in consequence of the violent bombardment. The
occluded air, by its impact against the oil, heats it; the oil begins to
circulate, carrying some of the air along with it, until the bubbles are
dispersed and the luminous points disappear. In this manner, unless
large bubbles are occluded in such way that circulation is rendered
impossible, a damaging break is averted, the only effect being a
moderate warming up of the oil. If, instead of the liquid, a solid
insulation, no matter how thick, were used, a breaking through and
injury of the apparatus would be inevitable.

The exclusion of gaseous matter from any apparatus in which the
dielectric is subjected to more or less rapidly changing electric forces
is, however, not only desirable in order to avoid a possible injury of
the apparatus, but also on account of economy. In a condenser, for
instance, as long as only a solid or only a liquid dielectric is used,
the loss is small; but if a gas under ordinary or small pressure be
present the loss may be very great. Whatever the nature of the force
acting in the dielectric may be, it seems that in a solid or liquid the
molecular displacement produced by the force is small: hence the product
of force and displacement is insignificant, unless the force be very
great; but in a gas the displacement, and therefore this product, is
considerable; the molecules are free to move, they reach high speeds,
and the energy of their impact is lost in heat or otherwise. If the gas
be strongly compressed, the displacement due to the force is made
smaller, and the losses are reduced.

In most of the succeeding experiments I prefer, chiefly on account of
the regular and positive action, to employ the alternator before
referred to. This is one of the several machines constructed by me for
the purpose of these investigations. It has 384 pole projections, and is
capable of giving currents of a frequency of about 10,000 per second.
This machine has been illustrated and briefly described in my first
paper before the American Institute of Electrical Engineers, May 20th,
1891, to which I have already referred. A more detailed description,
sufficient to enable any engineer to build a similar machine, will be
found in several electrical journals of that period.

The induction coils operated from the machine are rather small,
containing from 5,000 to 15,000 turns in the secondary. They are
immersed in boiled-out linseed oil, contained in wooden boxes covered
with zinc sheet.

I have found it advantageous to reverse the usual position of the wires,
and to wind, in these coils, the primaries on the top; thus allowing the
use of a much larger primary, which, of course, reduces the danger of
overheating and increases the output of the coil. I make the primary on
each side at least one centimetre shorter than the secondary, to prevent
the breaking through on the ends, which would surely occur unless the
insulation on the top of the secondary be very thick, and this, of
course, would be disadvantageous.

When the primary is made movable, which is necessary in some
experiments, and many times convenient for the purposes of adjustment, I
cover the secondary with wax, and turn it off in a lathe to a diameter
slightly smaller than the inside of the primary coil. The latter I
provide with a handle reaching out of the oil, which serves to shift it
in any position along the secondary.

I will now venture to make, in regard to the general manipulation of
induction coils, a few observations bearing upon points which have not
been fully appreciated in earlier experiments with such coils, and are
even now often overlooked.

The secondary of the coil possesses usually such a high self-induction
that the current through the wire is inappreciable, and may be so even
when the terminals are joined by a conductor of small resistance. If
capacity is added to the terminals, the self-induction is counteracted,
and a stronger current is made to flow through the secondary, though its
terminals are insulated from each other. To one entirely unacquainted
with the properties of alternating currents nothing will look more
puzzling. This feature was illustrated in the experiment performed at
the beginning with the top plates of wire gauze attached to the
terminals and the rubber plate. When the plates of wire gauze were close
together, and a small arc passed between them, the arc _prevented_ a
strong current from passing through the secondary, because it did away
with the capacity on the terminals; when the rubber plate was inserted
between, the capacity of the condenser formed counteracted the
self-induction of the secondary, a stronger current passed now, the coil
performed more work, and the discharge was by far more powerful.

The first thing, then, in operating the induction coil is to combine
capacity with the secondary to overcome the self-induction. If the
frequencies and potentials are very high, gaseous matter should be
carefully kept away from the charged surfaces. If Leyden jars are used,
they should be immersed in oil, as otherwise considerable dissipation
may occur if the jars are greatly strained. When high frequencies are
used, it is of equal importance to combine a condenser with the primary.
One may use a condenser connected to the ends of the primary or to the
terminals of the alternator, but the latter is not to be recommended, as
the machine might be injured. The best way is undoubtedly to use the
condenser in series with the primary and with the alternator, and to
adjust its capacity so as to annul the self-induction of both the
latter. The condenser should be adjustable by very small steps, and for
a finer adjustment a small oil condenser with movable plates may be used
conveniently.

I think it best at this juncture to bring before you a phenomenon,
observed by me some time ago, which to the purely scientific
investigator may perhaps appear more interesting than any of the results
which I have the privilege to present to you this evening.

It may be quite properly ranked among the brush phenomena--in fact, it
is a brush, formed at, or near, a single terminal in high vacuum.

[Illustration: FIG. 141.]

[Illustration: FIG. 142.]

In bulbs provided with a conducting terminal, though it be of aluminum,
the brush has but an ephemeral existence, and cannot, unfortunately, be
indefinitely preserved in its most sensitive state, even in a bulb
devoid of any conducting electrode. In studying the phenomenon, by all
means a bulb having no leading-in wire should be used. I have found it
best to use bulbs constructed as indicated in Figs. 141 and 142.

In Fig. 141 the bulb comprises an incandescent lamp globe _L_, in the
neck of which is sealed a barometer tube _b_, the end of which is blown
out to form a small sphere _s_. This sphere should be sealed as closely
as possible in the centre of the large globe. Before sealing, a thin
tube _t_, of aluminum sheet, may be slipped in the barometer tube, but
it is not important to employ it.

The small hollow sphere _s_ is filled with some conducting powder, and a
wire _w_ is cemented in the neck for the purpose of connecting the
conducting powder with the generator.

The construction shown in Fig. 142 was chosen in order to remove from
the brush any conducting body which might possibly affect it. The bulb
consists in this case of a lamp globe _L_, which has a neck _n_,
provided with a tube _b_ and small sphere _s_, sealed to it, so that two
entirely independent compartments are formed, as indicated in the
drawing. When the bulb is in use the neck _n_ is provided with a tinfoil
coating, which is connected to the generator and acts inductively upon
the moderately rarefied and highly conducted gas inclosed in the neck.
From there the current passes through the tube _b_ into the small sphere
_s_, to act by induction upon the gas contained in the globe _L_.

It is of advantage to make the tube _t_ very thick, the hole through it
very small, and to blow the sphere _s_ very thin. It is of the greatest
importance that the sphere _s_ be placed in the centre of the globe _L_.

[Illustration: FIG. 143.]

Figs. 143, 144 and 145 indicate different forms, or stages, of the
brush. Fig. 143 shows the brush as it first appears in a bulb provided
with a conducting terminal; but, as in such a bulb it very soon
disappears--often after a few minutes--I will confine myself to the
description of the phenomenon as seen in a bulb without conducting
electrode. It is observed under the following conditions:

When the globe _L_ (Figs. 141 and 142) is exhausted to a very high
degree, generally the bulb is not excited upon connecting the wire _w_
(Fig. 141) or the tinfoil coating of the bulb (Fig. 142) to the
terminal of the induction coil. To excite it, it is usually sufficient
to grasp the globe _L_ with the hand. An intense phosphorescence then
spreads at first over the globe, but soon gives place to a white, misty
light. Shortly afterward one may notice that the luminosity is unevenly
distributed in the globe, and after passing the current for some time
the bulb appears as in Fig. 144. From this stage the phenomenon will
gradually pass to that indicated in Fig. 145, after some minutes, hours,
days or weeks, according as the bulb is worked. Warming the bulb or
increasing the potential hastens the transit.

[Illustration: FIG. 144.]

[Illustration: FIG. 145.]

When the brush assumes the form indicated in Fig. 145, it may be brought
to a state of extreme sensitiveness to electrostatic and magnetic
influence. The bulb hanging straight down from a wire, and all objects
being remote from it, the approach of the observer at a few paces from
the bulb will cause the brush to fly to the opposite side, and if he
walks around the bulb it will always keep on the opposite side. It may
begin to spin around the terminal long before it reaches that sensitive
stage. When it begins to turn around, principally, but also before, it
is affected by a magnet, and at a certain stage it is susceptible to
magnetic influence to an astonishing degree. A small permanent magnet,
with its poles at a distance of no more than two centimetres, will
affect it visibly at a distance of two metres, slowing down or
accelerating the rotation according to how it is held relatively to the
brush. I think I have observed that at the stage when it is most
sensitive to magnetic, it is not most sensitive to electrostatic,
influence. My explanation is, that the electrostatic attraction between
the brush and the glass of the bulb, which retards the rotation, grows
much quicker than the magnetic influence when the intensity of the
stream is increased.

When the bulb hangs with the globe _L_ down, the rotation is always
clockwise. In the southern hemisphere it would occur in the opposite
direction and on the equator the brush should not turn at all. The
rotation may be reversed by a magnet kept at some distance. The brush
rotates best, seemingly, when it is at right angles to the lines of
force of the earth. It very likely rotates, when at its maximum speed,
in synchronism with the alternations, say, 10,000 times a second. The
rotation can be slowed down or accelerated by the approach or receding
of the observer, or any conducting body, but it cannot be reversed by
putting the bulb in any position. When it is in the state of the highest
sensitiveness and the potential or frequency be varied, the
sensitiveness is rapidly diminished. Changing either of these but little
will generally stop the rotation. The sensitiveness is likewise affected
by the variations of temperature. To attain great sensitiveness it is
necessary to have the small sphere _s_ in the centre of the globe _L_,
as otherwise the electrostatic action of the glass of the globe will
tend to stop the rotation. The sphere _s_ should be small and of uniform
thickness; any dissymmetry of course has the effect to diminish the
sensitiveness.

The fact that the brush rotates in a definite direction in a permanent
magnetic field seems to show that in alternating currents of very high
frequency the positive and negative impulses are not equal, but that one
always preponderates over the other.

Of course, this rotation in one direction may be due to the action of
the two elements of the same current upon each other, or to the action
of the field produced by one of the elements upon the other, as in a
series motor, without necessarily one impulse being stronger than the
other. The fact that the brush turns, as far as I could observe, in any
position, would speak for this view. In such case it would turn at any
point of the earth's surface. But, on the other hand, it is then hard to
explain why a permanent magnet should reverse the rotation, and one must
assume the preponderance of impulses of one kind.

As to the causes of the formation of the brush or stream, I think it is
due to the electrostatic action of the globe and the dissymmetry of the
parts. If the small bulb _s_ and the globe _L_ were perfect concentric
spheres, and the glass throughout of the same thickness and quality, I
think the brush would not form, as the tendency to pass would be equal
on all sides. That the formation of the stream is due to an irregularity
is apparent from the fact that it has the tendency to remain in one
position, and rotation occurs most generally only when it is brought out
of this position by electrostatic or magnetic influence. When in an
extremely sensitive state it rests in one position, most curious
experiments may be performed with it. For instance, the experimenter
may, by selecting a proper position, approach the hand at a certain
considerable distance to the bulb, and he may cause the brush to pass
off by merely stiffening the muscles of the arm. When it begins to
rotate slowly, and the hands are held at a proper distance, it is
impossible to make even the slightest motion without producing a visible
effect upon the brush. A metal plate connected to the other terminal of
the coil affects it at a great distance, slowing down the rotation often
to one turn a second.

I am firmly convinced that such a brush, when we learn how to produce it
properly, will prove a valuable aid in the investigation of the nature
of the forces acting in an electrostatic or magnetic field. If there is
any motion which is measurable going on in the space, such a brush ought
to reveal it. It is, so to speak, a beam of light, frictionless, devoid
of inertia.

I think that it may find practical applications in telegraphy. With such
a brush it would be possible to send dispatches across the Atlantic, for
instance, with any speed, since its sensitiveness may be so great that
the slightest changes will affect it. If it were possible to make the
stream more intense and very narrow, its deflections could be easily
photographed.

I have been interested to find whether there is a rotation of the stream
itself, or whether there is simply a stress traveling around the bulb.
For this purpose I mounted a light mica fan so that its vanes were in
the path of the brush. If the stream itself was rotating the fan would
be spun around. I could produce no distinct rotation of the fan,
although I tried the experiment repeatedly; but as the fan exerted a
noticeable influence on the stream, and the apparent rotation of the
latter was, in this case, never quite satisfactory, the experiment did
not appear to be conclusive.

I have been unable to produce the phenomenon with the disruptive
discharge coil, although every other of these phenomena can be well
produced by it--many, in fact, much better than with coils operated from
an alternator.

It may be possible to produce the brush by impulses of one direction, or
even by a steady potential, in which case it would be still more
sensitive to magnetic influence.

In operating an induction coil with rapidly alternating currents, we
realize with astonishment, for the first time, the great importance of
the relation of capacity, self-induction and frequency as regards the
general results. The effects of capacity are the most striking, for in
these experiments, since the self-induction and frequency both are high,
the critical capacity is very small, and need be but slightly varied to
produce a very considerable change. The experimenter may bring his body
in contact with the terminals of the secondary of the coil, or attach to
one or both terminals insulated bodies of very small bulk, such as
bulbs, and he may produce a considerable rise or fall of potential, and
greatly affect the flow of the current through the primary. In the
experiment before shown, in which a brush appears at a wire attached to
one terminal, and the wire is vibrated when the experimenter brings his
insulated body in contact with the other terminal of the coil, the
sudden rise of potential was made evident.

I may show you the behavior of the coil in another manner which
possesses a feature of some interest. I have here a little light fan of
aluminum sheet, fastened to a needle and arranged to rotate freely in a
metal piece screwed to one of the terminals of the coil. When the coil
is set to work, the molecules of the air are rhythmically attracted and
repelled. As the force with which they are repelled is greater than that
with which they are attracted, it results that there is a repulsion
exerted on the surfaces of the fan. If the fan were made simply of a
metal sheet, the repulsion would be equal on the opposite sides, and
would produce no effect. But if one of the opposing surfaces is
screened, or if, generally speaking, the bombardment on this side is
weakened in some way or other, there remains the repulsion exerted upon
the other, and the fan is set in rotation. The screening is best
effected by fastening upon one of the opposing sides of the fan
insulated conducting coatings, or, if the fan is made in the shape of an
ordinary propeller screw, by fastening on one side, and close to it, an
insulated metal plate. The static screen may, however, be omitted, and
simply a thickness of insulating material fastened to one of the sides
of the fan.

To show the behavior of the coil, the fan may be placed upon the
terminal and it will readily rotate when the coil is operated by
currents of very high frequency. With a steady potential, of course, and
even with alternating currents of very low frequency, it would not turn,
because of the very slow exchange of air and, consequently, smaller
bombardment; but in the latter case it might turn if the potential were
excessive. With a pin wheel, quite the opposite rule holds good; it
rotates best with a steady potential, and the effort is the smaller the
higher the frequency. Now, it is very easy to adjust the conditions so
that the potential is normally not sufficient to turn the fan, but that
by connecting the other terminal of the coil with an insulated body it
rises to a much greater value, so as to rotate the fan, and it is
likewise possible to stop the rotation by connecting to the terminal a
body of different size, thereby diminishing the potential.

Instead of using the fan in this experiment, we may use the "electric"
radiometer with similar effect. But in this case it will be found that
the vanes will rotate only at high exhaustion or at ordinary pressures;
they will not rotate at moderate pressures, when the air is highly
conducting. This curious observation was made conjointly by Professor
Crookes and myself. I attribute the result to the high conductivity of
the air, the molecules of which then do not act as independent carriers
of electric charges, but act all together as a single conducting body.
In such case, of course, if there is any repulsion at all of the
molecules from the vanes, it must be very small. It is possible,
however, that the result is in part due to the fact that the greater
part of the discharge passes from the leading-in wire through the highly
conducting gas, instead of passing off from the conducting vanes.

In trying the preceding experiment with the electric radiometer the
potential should not exceed a certain limit, as then the electrostatic
attraction between the vanes and the glass of the bulb may be so great
as to stop the rotation.

A most curious feature of alternate currents of high frequencies and
potentials is that they enable us to perform many experiments by the use
of one wire only. In many respects this feature is of great interest.

In a type of alternate current motor invented by me some years ago I
produced rotation by inducing, by means of a single alternating current
passed through a motor circuit, in the mass or other circuits of the
motor, secondary currents, which, jointly with the primary or inducing
current, created a moving field of force. A simple but crude form of
such a motor is obtained by winding upon an iron core a primary, and
close to it a secondary coil, joining the ends of the latter and placing
a freely movable metal disc within the influence of the field produced
by both. The iron core is employed for obvious reasons, but it is not
essential to the operation. To improve the motor, the iron core is made
to encircle the armature. Again to improve, the secondary coil is made
to partly overlap the primary, so that it cannot free itself from a
strong inductive action of the latter, repel its lines as it may. Once
more to improve, the proper difference of phase is obtained between the
primary and secondary currents by a condenser, self-induction,
resistance or equivalent windings.

I had discovered, however, that rotation is produced by means of a
single coil and core; my explanation of the phenomenon, and leading
thought in trying the experiment, being that there must be a true time
lag in the magnetization of the core. I remember the pleasure I had
when, in the writings of Professor Ayrton, which came later to my hand,
I found the idea of the time lag advocated. Whether there is a true time
lag, or whether the retardation is due to eddy currents circulating in
minute paths, must remain an open question, but the fact is that a coil
wound upon an iron core and traversed by an alternating current creates
a moving field of force, capable of setting an armature in rotation. It
is of some interest, in conjunction with the historical Arago
experiment, to mention that in lag or phase motors I have produced
rotation in the opposite direction to the moving field, which means that
in that experiment the magnet may not rotate, or may even rotate in the
opposite direction to the moving disc. Here, then, is a motor
(diagrammatically illustrated in Fig. 146), comprising a coil and iron
core, and a freely movable copper disc in proximity to the latter.

[Illustration: FIG. 146.]

To demonstrate a novel and interesting feature, I have, for a reason
which I will explain, selected this type of motor. When the ends of the
coil are connected to the terminals of an alternator the disc is set in
rotation. But it is not this experiment, now well known, which I desire
to perform. What I wish to show you is that this motor rotates with
_one single_ connection between it and the generator; that is to say,
one terminal of the motor is connected to one terminal of the
generator--in this case the secondary of a high-tension induction
coil--the other terminals of motor and generator being insulated in
space. To produce rotation it is generally (but not absolutely)
necessary to connect the free end of the motor coil to an insulated body
of some size. The experimenter's body is more than sufficient. If he
touches the free terminal with an object held in the hand, a current
passes through the coil and the copper disc is set in rotation. If an
exhausted tube is put in series with the coil, the tube lights
brilliantly, showing the passage of a strong current. Instead of the
experimenter's body, a small metal sheet suspended on a cord may be used
with the same result. In this case the plate acts as a condenser in
series with the coil. It counteracts the self-induction of the latter
and allows a strong current to pass. In such a combination, the greater
the self-induction of the coil the smaller need be the plate, and this
means that a lower frequency, or eventually a lower potential, is
required to operate the motor. A single coil wound upon a core has a
high self-induction; for this reason, principally, this type of motor
was chosen to perform the experiment. Were a secondary closed coil wound
upon the core, it would tend to diminish the self-induction, and then
it would be necessary to employ a much higher frequency and potential.
Neither would be advisable, for a higher potential would endanger the
insulation of the small primary coil, and a higher frequency would
result in a materially diminished torque.

It should be remarked that when such a motor with a closed secondary is
used, it is not at all easy to obtain rotation with excessive
frequencies, as the secondary cuts off almost completely the lines of
the primary--and this, of course, the more, the higher the
frequency--and allows the passage of but a minute current. In such a
case, unless the secondary is closed through a condenser, it is almost
essential, in order to produce rotation, to make the primary and
secondary coils overlap each other more or less.

But there is an additional feature of interest about this motor, namely,
it is not necessary to have even a single connection between the motor
and generator, except, perhaps, through the ground; for not only is an
insulated plate capable of giving off energy into space, but it is
likewise capable of deriving it from an alternating electrostatic field,
though in the latter case the available energy is much smaller. In this
instance one of the motor terminals is connected to the insulated plate
or body located within the alternating electrostatic field, and the
other terminal preferably to the ground.

It is quite possible, however, that such "no wire" motors, as they might
be called, could be operated by conduction through the rarefied air at
considerable distances. Alternate currents, especially of high
frequencies, pass with astonishing freedom through even slightly
rarefied gases. The upper strata of the air are rarefied. To reach a
number of miles out into space requires the overcoming of difficulties
of a merely mechanical nature. There is no doubt that with the enormous
potentials obtainable by the use of high frequencies and oil insulation,
luminous discharges might be passed through many miles of rarefied air,
and that, by thus directing the energy of many hundreds or thousands of
horse-power, motors or lamps might be operated at considerable distances
from stationary sources. But such schemes are mentioned merely as
possibilities. We shall have no need to transmit power in this way. We
shall have no need to _transmit_ power at all. Ere many generations
pass, our machinery will be driven by a power obtainable at any point of
the universe. This idea is not novel. Men have been led to it long ago
by instinct or reason. It has been expressed in many ways, and in many
places, in the history of old and new. We find it in the delightful myth
of Antheus, who derives power from the earth; we find it among the
subtle speculations of one of your splendid mathematicians, and in many
hints and statements of thinkers of the present time. Throughout space
there is energy. Is this energy static or kinetic? If static our hopes
are in vain; if kinetic--and this we know it is, for certain--then it is
a mere question of time when men will succeed in attaching their
machinery to the very wheelwork of nature. Of all, living or dead,
Crookes came nearest to doing it. His radiometer will turn in the light
of day and in the darkness of the night; it will turn everywhere where
there is heat, and heat is everywhere. But, unfortunately, this
beautiful little machine, while it goes down to posterity as the most
interesting, must likewise be put on record as the most inefficient
machine ever invented!

The preceding experiment is only one of many equally interesting
experiments which may be performed by the use of only one wire with
alternations of high potential and frequency. We may connect an
insulated line to a source of such currents, we may pass an
inappreciable current over the line, and on any point of the same we are
able to obtain a heavy current, capable of fusing a thick copper wire.
Or we may, by the help of some artifice, decompose a solution in any
electrolytic cell by connecting only one pole of the cell to the line or
source of energy. Or we may, by attaching to the line, or only bringing
into its vicinity, light up an incandescent lamp, an exhausted tube, or
a phosphorescent bulb.

However impracticable this plan of working may appear in many cases, it
certainly seems practicable, and even recommendable, in the production
of light. A perfected lamp would require but little energy, and if wires
were used at all we ought to be able to supply that energy without a
return wire.

It is now a fact that a body may be rendered incandescent or
phosphorescent by bringing it either in single contact or merely in the
vicinity of a source of electric impulses of the proper character, and
that in this manner a quantity of light sufficient to afford a practical
illuminant may be produced. It is, therefore, to say the least, worth
while to attempt to determine the best conditions and to invent the best
appliances for attaining this object.

Some experiences have already been gained in this direction, and I will
dwell on them briefly, in the hope that they might prove useful.

The heating of a conducting body inclosed in a bulb, and connected to a
source of rapidly alternating electric impulses, is dependent on so many
things of a different nature, that it would be difficult to give a
generally applicable rule under which the maximum heating occurs. As
regards the size of the vessel, I have lately found that at ordinary or
only slightly differing atmospheric pressures, when air is a good
insulator, and hence practically the same amount of energy by a certain
potential and frequency is given off from the body, whether the bulb be
small or large, the body is brought to a higher temperature if enclosed
in a small bulb, because of the better confinement of heat in this case.

At lower pressures, when air becomes more or less conducting, or if the
air be sufficiently warmed to become conducting, the body is rendered
more intensely incandescent in a large bulb, obviously because, under
otherwise equal conditions of test, more energy may be given off from
the body when the bulb is large.

At very high degrees of exhaustion, when the matter in the bulb becomes
"radiant," a large bulb has still an advantage, but a comparatively
slight one, over the small bulb.

Finally, at excessively high degrees of exhaustion, which cannot be
reached except by the employment of special means, there seems to be,
beyond a certain and rather small size of vessel, no perceptible
difference in the heating.

These observations were the result of a number of experiments, of which
one, showing the effect of the size of the bulb at a high degree of
exhaustion, may be described and shown here, as it presents a feature of
interest. Three spherical bulbs of 2 inches, 3 inches and 4 inches
diameter were taken, and in the centre of each was mounted an equal
length of an ordinary incandescent lamp filament of uniform thickness.
In each bulb the piece of filament was fastened to the leading-in wire
of platinum, contained in a glass stem sealed in the bulb; care being
taken, of course, to make everything as nearly alike as possible. On
each glass stem in the inside of the bulb was slipped a highly polished
tube made of aluminum sheet, which fitted the stem and was held on it by
spring pressure. The function of this aluminum tube will be explained
subsequently. In each bulb an equal length of filament protruded above
the metal tube. It is sufficient to say now that under these conditions
equal lengths of filament of the same thickness--in other words, bodies
of equal bulk--were brought to incandescence. The three bulbs were
sealed to a glass tube, which was connected to a Sprengel pump. When a
high vacuum had been reached, the glass tube carrying the bulbs was
sealed off. A current was then turned on successively on each bulb, and
it was found that the filaments came to about the same brightness, and,
if anything, the smallest bulb, which was placed midway between the two
larger ones, may have been slightly brighter. This result was expected,
for when either of the bulbs was connected to the coil the luminosity
spread through the other two, hence the three bulbs constituted really
one vessel. When all the three bulbs were connected in multiple arc to
the coil, in the largest of them the filament glowed brightest, in the
next smaller it was a little less bright, and in the smallest it only
came to redness. The bulbs were then sealed off and separately tried.
The brightness of the filaments was now such as would have been expected
on the supposition that the energy given off was proportionate to the
surface of the bulb, this surface in each case representing one of the
coatings of a condenser. Accordingly, there was less difference between
the largest and the middle sized than between the latter and the
smallest bulb.

An interesting observation was made in this experiment. The three bulbs
were suspended from a straight bare wire connected to a terminal of a
coil, the largest bulb being placed at the end of the wire, at some
distance from it the smallest bulb, and at an equal distance from the
latter the middle-sized one. The carbons glowed then in both the larger
bulbs about as expected, but the smallest did not get its share by far.
This observation led me to exchange the position of the bulbs, and I
then observed that whichever of the bulbs was in the middle was by far
less bright than it was in any other position. This mystifying result
was, of course, found to be due to the electrostatic action between the
bulbs. When they were placed at a considerable distance, or when they
were attached to the corners of an equilateral triangle of copper wire,
they glowed in about the order determined by their surfaces.

As to the shape of the vessel, it is also of some importance, especially
at high degrees of exhaustion. Of all the possible constructions, it
seems that a spherical globe with the refractory body mounted in its
centre is the best to employ. By experience it has been demonstrated
that in such a globe a refractory body of a given bulk is more easily
brought to incandescence than when differently shaped bulbs are used.
There is also an advantage in giving to the incandescent body the shape
of a sphere, for self-evident reasons. In any case the body should be
mounted in the centre, where the atoms rebounding from the glass
collide. This object is best attained in the spherical bulb; but it is
also attained in a cylindrical vessel with one or two straight filaments
coinciding with its axis, and possibly also in parabolical or spherical
bulbs with refractory body or bodies placed in the focus or foci of the
same; though the latter is not probable, as the electrified atoms should
in all cases rebound normally from the surface they strike, unless the
speed were excessive, in which case they _would_ probably follow the
general law of reflection. No matter what shape the vessel may have, if
the exhaustion be low, a filament mounted in the globe is brought to the
same degree of incandescence in all parts; but if the exhaustion be high
and the bulb be spherical or pear-shaped, as usual, focal points form
and the filament is heated to a higher degree at or near such points.

To illustrate the effect, I have here two small bulbs which are alike,
only one is exhausted to a low and the other to a very high degree. When
connected to the coil, the filament in the former glows uniformly
throughout all its length; whereas in the latter, that portion of the
filament which is in the centre of the bulb glows far more intensely
than the rest. A curious point is that the phenomenon occurs even if two
filaments are mounted in a bulb, each being connected to one terminal of
the coil, and, what is still more curious, if they be very near
together, provided the vacuum be very high. I noted in experiments with
such bulbs that the filaments would give way usually at a certain point,
and in the first trials I attributed it to a defect in the carbon. But
when the phenomenon occurred many times in succession I recognized its
real cause.

In order to bring a refractory body inclosed in a bulb to incandescence,
it is desirable, on account of economy, that all the energy supplied to
the bulb from the source should reach without loss the body to be
heated; from there, and from nowhere else, it should be radiated. It is,
of course, out of the question to reach this theoretical result, but it
is possible by a proper construction of the illuminating device to
approximate it more or less.

For many reasons, the refractory body is placed in the centre of the
bulb, and it is usually supported on a glass stem containing the
leading-in wire. As the potential of this wire is alternated, the
rarefied gas surrounding the stem is acted upon inductively, and the
glass stem is violently bombarded and heated. In this manner by far the
greater portion of the energy supplied to the bulb--especially when
exceedingly high frequencies are used--may be lost for the purpose
contemplated. To obviate this loss, or at least to reduce it to a
minimum, I usually screen the rarefied gas surrounding the stem from the
inductive action of the leading-in wire by providing the stem with a
tube or coating of conducting material. It seems beyond doubt that the
best among metals to employ for this purpose is aluminum, on account of
its many remarkable properties. Its only fault is that it is easily
fusible, and, therefore, its distance from the incandescing body should
be properly estimated. Usually, a thin tube, of a diameter somewhat
smaller than that of the glass stem, is made of the finest aluminum
sheet, and slipped on the stem. The tube is conveniently prepared by
wrapping around a rod fastened in a lathe a piece of aluminum sheet of
proper size, grasping the sheet firmly with clean chamois leather or
blotting paper, and spinning the rod very fast. The sheet is wound
tightly around the rod, and a highly polished tube of one or three
layers of the sheet is obtained. When slipped on the stem, the pressure
is generally sufficient to prevent it from slipping off, but, for
safety, the lower edge of the sheet may be turned inside. The upper
inside corner of the sheet--that is, the one which is nearest to the
refractory incandescent body--should be cut out diagonally, as it often
happens that, in consequence of the intense heat, this corner turns
toward the inside and comes very near to, or in contact with, the wire,
or filament, supporting the refractory body. The greater part of the
energy supplied to the bulb is then used up in heating the metal tube,
and the bulb is rendered useless for the purpose. The aluminum sheet
should project above the glass stem more or less--one inch or so--or
else, if the glass be too close to the incandescing body, it may be
strongly heated and become more or less conducting, whereupon it may be
ruptured, or may, by its conductivity, establish a good electrical
connection between the metal tube and the leading-in wire, in which
case, again, most of the energy will be lost in heating the former.
Perhaps the best way is to make the top of the glass tube, for about an
inch, of a much smaller diameter. To still further reduce the danger
arising from the heating of the glass stem, and also with the view of
preventing an electrical connection between the metal tube and the
electrode, I preferably wrap the stem with several layers of thin mica,
which extends at least as far as the metal tube. In some bulbs I have
also used an outside insulating cover.

The preceding remarks are only made to aid the experimenter in the first
trials, for the difficulties which he encounters he may soon find means
to overcome in his own way.

To illustrate the effect of the screen, and the advantage of using it, I
have here two bulbs of the same size, with their stems, leading-in wires
and incandescent lamp filaments tied to the latter, as nearly alike as
possible. The stem of one bulb is provided with an aluminum tube, the
stem of the other has none. Originally the two bulbs were joined by a
tube which was connected to a Sprengel pump. When a high vacuum had been
reached, first the connecting tube, and then the bulbs, were sealed off;
they are therefore of the same degree of exhaustion. When they are
separately connected to the coil giving a certain potential, the carbon
filament in the bulb provided with the aluminum screen is rendered
highly incandescent, while the filament in the other bulb may, with the
same potential, not even come to redness, although in reality the latter
bulb takes generally more energy than the former. When they are both
connected together to the terminal, the difference is even more
apparent, showing the importance of the screening. The metal tube placed
on the stem containing the leading-in wire performs really two distinct
functions: First, it acts more or less as an electrostatic screen, thus
economizing the energy supplied to the bulb; and, second, to whatever
extent it may fail to act electrostatically, it acts mechanically,
preventing the bombardment, and consequently intense heating and
possible deterioration of the slender support of the refractory
incandescent body, or of the glass stem containing the leading-in wire.
I say _slender_ support, for it is evident that in order to confine the
heat more completely to the incandescing body its support should be very
thin, so as to carry away the smallest possible amount of heat by
conduction. Of all the supports used I have found an ordinary
incandescent lamp filament to be the best, principally because among
conductors it can withstand the highest degree of heat.

The effectiveness of the metal tube as an electrostatic screen depends
largely on the degree of exhaustion.

At excessively high degrees of exhaustion--which are reached by using
great care and special means in connection with the Sprengel pump--when
the matter in the globe is in the ultra-radiant state, it acts most
perfectly. The shadow of the upper edge of the tube is then sharply
defined upon the bulb.

At a somewhat lower degree of exhaustion, which is about the ordinary
"non-striking" vacuum, and generally as long as the matter moves
predominantly in straight lines, the screen still does well. In
elucidation of the preceding remark it is necessary to state that what
is a "non-striking" vacuum for a coil operated as ordinarily, by
impulses, or currents, of low frequency, is not so, by far, when the
coil is operated by currents of very high frequency. In such case the
discharge may pass with great freedom through the rarefied gas through
which a low frequency discharge may not pass, even though the potential
be much higher. At ordinary atmospheric pressures just the reverse rule
holds good: the higher the frequency, the less the spark discharge is
able to jump between the terminals, especially if they are knobs or
spheres of some size.

Finally, at very low degrees of exhaustion, when the gas is well
conducting, the metal tube not only does not act as an electrostatic
screen, but even is a drawback, aiding to a considerable extent the
dissipation of the energy laterally from the leading-in wire. This, of
course, is to be expected. In this case, namely, the metal tube is in
good electrical connection with the leading-in wire, and most of the
bombardment is directed upon the tube. As long as the electrical
connection is not good, the conducting tube is always of some advantage,
for although it may not greatly economize energy, still it protects the
support of the refractory button, and is the means of concentrating more
energy upon the same.

To whatever extent the aluminum tube performs the function of a screen,
its usefulness is therefore limited to very high degrees of exhaustion
when it is insulated from the electrode--that is, when the gas as a
whole is non-conducting, and the molecules, or atoms, act as independent
carriers of electric charges.

In addition to acting as a more or less effective screen, in the true
meaning of the word, the conducting tube or coating may also act, by
reason of its conductivity, as a sort of equalizer or dampener of the
bombardment against the stem. To be explicit, I assume the action to be
as follows: Suppose a rhythmical bombardment to occur against the
conducting tube by reason of its imperfect action as a screen, it
certainly must happen that some molecules, or atoms, strike the tube
sooner than others. Those which come first in contact with it give up
their superfluous charge, and the tube is electrified, the
electrification instantly spreading over its surface. But this must
diminish the energy lost in the bombardment, for two reasons: first, the
charge given up by the atoms spreads over a great area, and hence the
electric density at any point is small, and the atoms are repelled with
less energy than they would be if they struck against a good insulator;
secondly, as the tube is electrified by the atoms which first come in
contact with it, the progress of the following atoms against the tube is
more or less checked by the repulsion which the electrified tube must
exert upon the similarly electrified atoms. This repulsion may perhaps
be sufficient to prevent a large portion of the atoms from striking the
tube, but at any rate it must diminish the energy of their impact. It is
clear that when the exhaustion is very low, and the rarefied gas well
conducting, neither of the above effects can occur, and, on the other
hand, the fewer the atoms, with the greater freedom they move; in other
words, the higher the degree of exhaustion, up to a limit, the more
telling will be both the effects.

[Illustration: FIG. 147.]

[Illustration: FIG. 148.]

What I have just said may afford an explanation of the phenomenon
observed by Prof. Crookes, namely, that a discharge through a bulb is
established with much greater facility when an insulator than when a
conductor is present in the same. In my opinion, the conductor acts as a
dampener of the motion of the atoms in the two ways pointed out; hence,
to cause a visible discharge to pass through the bulb, a much higher
potential is needed if a conductor, especially of much surface, be
present.

For the sake of elucidating of some of the remarks before made, I must
now refer to Figs. 147, 148 and 149, which illustrate various
arrangements with a type of bulb most generally used.

Fig. 147 is a section through a spherical bulb L, with the glass stem
_s_, contains the leading-in wire _w_, which has a lamp filament _l_
fastened to it, serving to support the refractory button _m_ in the
centre. M is a sheet of thin mica wound in several layers around the
stem _s_, and _a_ is the aluminum tube.

Fig. 148 illustrates such a bulb in a somewhat more advanced stage of
perfection. A metallic tube S is fastened by means of some cement to the
neck of the tube. In the tube is screwed a plug P, of insulating
material, in the centre of which is fastened a metallic terminal _t_,
for the connection to the leading-in wire _w_. This terminal must be
well insulated from the metal tube S; therefore, if the cement used is
conducting--and most generally it is sufficiently so--the space between
the plug P and the neck of the bulb should be filled with some good
insulating material, such as mica powder.


Fig. 149 shows a bulb made for experimental purposes. In this bulb the
aluminum tube is provided with an external connection, which serves to
investigate the effect of the tube under various conditions. It is
referred to chiefly to suggest a line of experiment followed.

Since the bombardment against the stem containing the leading-in wire is
due to the inductive action of the latter upon the rarefied gas, it is
of advantage to reduce this action as far as practicable by employing a
very thin wire, surrounded by a very thick insulation of glass or other
material, and by making the wire passing through the rarefied gas as
short as practicable. To combine these features I employ a large tube T
(Fig. 150), which protrudes into the bulb to some distance, and carries
on the top a very short glass stem _s_, into which is sealed the
leading-in wire _w_, and I protect the top of the glass stem against the
heat by a small aluminum tube _a_ and a layer of mica underneath the
same, as usual. The wire _w_, passing through the large tube to the
outside of the bulb, should be well insulated--with a glass tube, for
instance--and the space between ought to be filled out with some
excellent insulator. Among many insulating powders I have found that
mica powder is the best to employ. If this precaution is not taken, the
tube T, protruding into the bulb, will surely be cracked in consequence
of the heating by the brushes which are apt to form in the upper part of
the tube, near the exhausted globe, especially if the vacuum be
excellent, and therefore the potential necessary to operate the lamp be
very high.

[Illustration: FIG. 149.]

[Illustration: FIG. 150.]

Fig. 151 illustrates a similar arrangement, with a large tube T
protruding into the part of the bulb containing the refractory button
_m_. In this case the wire leading from the outside into the bulb is
omitted, the energy required being supplied through condenser coatings C
C. The insulating packing P should in this construction be tightly
fitting to the glass, and rather wide, or otherwise the discharge might
avoid passing through the wire _w_, which connects the inside condenser
coating to the incandescent button _m_.

The molecular bombardment against the glass stem in the bulb is a source
of great trouble. As an illustration I will cite a phenomenon only too
frequently and unwillingly observed. A bulb, preferably a large one, may
be taken, and a good conducting body, such as a piece of carbon, may be
mounted in it upon a platinum wire sealed in the glass stem. The bulb
may be exhausted to a fairly high degree, nearly to the point when
phosphorescence begins to appear. When the bulb is connected with the
coil, the piece of carbon, if small, may become highly incandescent at
first, but its brightness immediately diminishes, and then the discharge
may break through the glass somewhere in the middle of the stem, in the
form of bright sparks, in spite of the fact that the platinum wire is in
good electrical connection with the rarefied gas through the piece of
carbon or metal at the top. The first sparks are singularly bright,
recalling those drawn from a clear surface of mercury. But, as they heat
the glass rapidly, they, of course, lose their brightness, and cease
when the glass at the ruptured place becomes incandescent, or generally
sufficiently hot to conduct. When observed for the first time the
phenomenon must appear very curious, and shows in a striking manner how
radically different alternate currents, or impulses, of high frequency
behave, as compared with steady currents, or currents of low frequency.
With such currents--namely, the latter--the phenomenon would of course
not occur. When frequencies such as are obtained by mechanical means are
used, I think that the rupture of the glass is more or less the
consequence of the bombardment, which warms it up and impairs its
insulating power; but with frequencies obtainable with condensers I have
no doubt that the glass may give way without previous heating. Although
this appears most singular at first, it is in reality what we might
expect to occur. The energy supplied to the wire leading into the bulb
is given off partly by direct action through the carbon button, and
partly by inductive action through the glass surrounding the wire. The
case is thus analogous to that in which a condenser shunted by a
conductor of low resistance is connected to a source of alternating
current. As long as the frequencies are low, the conductor gets the most
and the condenser is perfectly safe; but when the frequency becomes
excessive, the _role_ of the conductor may become quite insignificant.
In the latter case the difference of potential at the terminals of the
condenser may become so great as to rupture the dielectric,
notwithstanding the fact that the terminals are joined by a conductor of
low resistance.

It is, of course, not necessary, when it is desired to produce the
incandescence of a body inclosed in a bulb by means of these currents,
that the body should be a conductor, for even a perfect non-conductor
may be quite as readily heated. For this purpose it is sufficient to
surround a conducting electrode with a non-conducting material, as, for
instance, in the bulb described before in Fig. 150, in which a thin
incandescent lamp filament is coated with a non-conductor, and supports
a button of the same material on the top. At the start the bombardment
goes on by inductive action through the non-conductor, until the same is
sufficiently heated to become conducting, when the bombardment continues
in the ordinary way.

[Illustration: FIG. 151.]

[Illustration: FIG. 152.]

A different arrangement used in some of the bulbs constructed is
illustrated in Fig. 152. In this instance a non-conductor _m_ is mounted
in a piece of common arc light carbon so as to project some small
distance above the latter. The carbon piece is connected to the
leading-in wire passing through a glass stem, which is wrapped with
several layers of mica. An aluminum tube _a_ is employed as usual for
screening. It is so arranged that it reaches very nearly as high as the
carbon and only the non-conductor _m_ projects a little above it. The
bombardment goes at first against the upper surface of carbon, the lower
parts being protected by the aluminum tube. As soon, however, as the
non-conductor _m_ is heated it is rendered good conducting, and then it
becomes the centre of the bombardment, being most exposed to the same.

I have also constructed during these experiments many such single-wire
bulbs with or without internal electrode, in which the radiant matter
was projected against, or focused upon, the body to be rendered
incandescent. Fig. 153 (page 263) illustrates one of the bulbs used. It
consists of a spherical globe L, provided with a long neck _n_, on top,
for increasing the action in some cases by the application of an
external conducting coating. The globe L is blown out on the bottom into
a very small bulb _b_, which serves to hold it firmly in a socket S of
insulating material into which it is cemented. A fine lamp filament _f_,
supported on a wire _w_, passes through the centre of the globe L. The
filament is rendered incandescent in the middle portion, where the
bombardment proceeding from the lower inside surface of the globe is
most intense. The lower portion of the globe, as far as the socket S
reaches, is rendered conducting, either by a tinfoil coating or
otherwise, and the external electrode is connected to a terminal of the
coil.

The arrangement diagrammatically indicated in Fig. 153 was found to be
an inferior one when it was desired to render incandescent a filament or
button supported in the centre of the globe, but it was convenient when
the object was to excite phosphorescence.

In many experiments in which bodies of different kind were mounted in
the bulb as, for instance, indicated in Fig. 152, some observations of
interest were made.

It was found, among other things, that in such cases, no matter where
the bombardment began, just as soon as a high temperature was reached
there was generally one of the bodies which seemed to take most of the
bombardment upon itself, the other, or others, being thereby relieved.
The quality appeared to depend principally on the point of fusion, and
on the facility with which the body was "evaporated," or, generally
speaking, disintegrated--meaning by the latter term not only the
throwing off of atoms, but likewise of large lumps. The observation made
was in accordance with generally accepted notions. In a highly exhausted
bulb, electricity is carried off from the electrode by independent
carriers, which are partly the atoms, or molecules, of the residual
atmosphere, and partly the atoms, molecules, or lumps thrown off from
the electrode. If the electrode is composed of bodies of different
character, and if one of these is more easily disintegrated than the
other, most of the electricity supplied is carried off from that body,
which is then brought to a higher temperature than the others, and this
the more, as upon an increase of the temperature the body is still more
easily disintegrated.

It seems to me quite probable that a similar process takes place in the
bulb even with a homogeneous electrode, and I think it to be the
principal cause of the disintegration. There is bound to be some
irregularity, even if the surface is highly polished, which, of course,
is impossible with most of the refractory bodies employed as electrodes.
Assume that a point of the electrode gets hotter; instantly most of the
discharge passes through that point, and a minute patch it probably
fused and evaporated. It is now possible that in consequence of the
violent disintegration the spot attacked sinks in temperature, or that a
counter force is created, as in an arc; at any rate, the local tearing
off meets with the limitations incident to the experiment, whereupon the
same process occurs on another place. To the eye the electrode appears
uniformly brilliant, but there are upon it points constantly shifting
and wandering around, of a temperature far above the mean, and this
materially hastens the process of deterioration. That some such thing
occurs, at least when the electrode is at a lower temperature,
sufficient experimental evidence can be obtained in the following
manner: Exhaust a bulb to a very high degree, so that with a fairly high
potential the discharge cannot pass--that is, not a _luminous_ one, for
a weak invisible discharge occurs always, in all probability. Now raise
slowly and carefully the potential, leaving the primary current on no
more than for an instant. At a certain point, two, three, or half a
dozen phosphorescent spots will appear on the globe. These places of the
glass are evidently more violently bombarded than others, this being due
to the unevenly distributed electric density, necessitated, of course,
by sharp projections, or, generally speaking, irregularities of the
electrode. But the luminous patches are constantly changing in position,
which is especially well observable if one manages to produce very few,
and this indicates that the configuration of the electrode is rapidly
changing.

From experiences of this kind I am led to infer that, in order to be
most durable, the refractory button in the bulb should be in the form of
a sphere with a highly polished surface. Such a small sphere could be
manufactured from a diamond or some other crystal, but a better way
would be to fuse, by the employment of extreme degrees of temperature,
some oxide--as, for instance, zirconia--into a small drop, and then keep
it in the bulb at a temperature somewhat below its point of fusion.

Interesting and useful results can, no doubt, be reached in the
direction of extreme degrees of heat. How can such high temperatures be
arrived at? How are the highest degrees of heat reached in nature? By
the impact of stars, by high speeds and collisions. In a collision any
rate of heat generation may be attained. In a chemical process we are
limited. When oxygen and hydrogen combine, they fall, metaphorically
speaking, from a definite height. We cannot go very far with a blast,
nor by confining heat in a furnace, but in an exhausted bulb we can
concentrate any amount of energy upon a minute button. Leaving
practicability out of consideration, this, then, would be the means
which, in my opinion, would enable us to reach the highest temperature.
But a great difficulty when proceeding in this way is encountered,
namely, in most cases the body is carried off before it can fuse and
form a drop. This difficulty exists principally with an oxide, such as
zirconia, because it cannot be compressed in so hard a cake that it
would not be carried off quickly. I have endeavored repeatedly to fuse
zirconia, placing it in a cup of arc light carbon, as indicated in Fig.
152. It glowed with a most intense light, and the stream of the
particles projected out of the carbon cup was of a vivid white; but
whether it was compressed in a cake or made into a paste with carbon, it
was carried off before it could be fused. The carbon cup, containing
zirconia, had to be mounted very low in the neck of a large bulb, as the
heating of the glass by the projected particles of the oxide was so
rapid that in the first trial the bulb was cracked almost in an instant,
when the current was turned on. The heating of the glass by the
projected particles was found to be always greater when the carbon cup
contained a body which was rapidly carried off--I presume, because in
such cases, with the same potential, higher speeds were reached, and
also because, per unit of time, more matter was projected--that is, more
particles would strike the glass.

The before-mentioned difficulty did not exist, however, when the body
mounted in the carbon cup offered great resistance to deterioration. For
instance, when an oxide was first fused in an oxygen blast, and then
mounted in the bulb, it melted very readily into a drop.

Generally, during the process of fusion, magnificent light effects were
noted, of which it would be difficult to give an adequate idea. Fig. 152
is intended to illustrate the effect observed with a ruby drop. At first
one may see a narrow funnel of white light projected against the top of
the globe, where it produces an irregularly outlined phosphorescent
patch. When the point of the ruby fuses, the phosphorescence becomes
very powerful; but as the atoms are projected with much greater speed
from the surface of the drop, soon the glass gets hot and "tired," and
now only the outer edge of the patch glows. In this manner an intensely
phosphorescent, sharply defined line, _l_, corresponding to the outline
of the drop, is produced, which spreads slowly over the globe as the
drop gets larger. When the mass begins to boil, small bubbles and
cavities are formed, which cause dark colored spots to sweep across the
globe. The bulb may be turned downward without fear of the drop falling
off, as the mass possesses considerable viscosity.

I may mention here another feature of some interest, which I believe to
have noted in the course of these experiments, though the observations
do not amount to a certitude. It _appeared_ that under the molecular
impact caused by the rapidly alternating potential, the body was fused
and maintained in that state at a lower temperature in a highly
exhausted bulb than was the case at normal pressure and application of
heat in the ordinary way--that is, at least, judging from the quantity
of the light emitted. One of the experiments performed may be mentioned
here by way of illustration. A small piece of pumice stone was stuck on
a platinum wire, and first melted to it in a gas burner. The wire was
next placed between two pieces of charcoal, and a burner applied, so as
to produce an intense heat, sufficient to melt down the pumice stone
into a small glass-like button. The platinum wire had to be taken of
sufficient thickness, to prevent its melting in the fire. While in the
charcoal fire, or when held in a burner to get a better idea of the
degree of heat, the button glowed with great brilliancy. The wire with
the button was then mounted in a bulb, and upon exhausting the same to a
high degree, the current was turned on slowly, so as to prevent the
cracking of the button. The button was heated to the point of fusion,
and when it melted, it did not, apparently, glow with the same
brilliancy as before, and this would indicate a lower temperature.
Leaving out of consideration the observer's possible, and even probable,
error, the question is, can a body under these conditions be brought
from a solid to a liquid state with the evolution of _less_ light?

When the potential of a body is rapidly alternated, it is certain that
the structure is jarred. When the potential is very high, although the
vibrations may be few--say 20,000 per second--the effect upon the
structure may be considerable. Suppose, for example, that a ruby is
melted into a drop by a steady application of energy. When it forms a
drop, it will emit visible and invisible waves, which will be in a
definite ratio, and to the eye the drop will appear to be of a certain
brilliancy. Next, suppose we diminish to any degree we choose the energy
steadily supplied, and, instead, supply energy which rises and falls
according to a certain law. Now, when the drop is formed, there will be
emitted from it three different kinds of vibrations--the ordinary
visible, and two kinds of invisible waves: that is, the ordinary dark
waves of all lengths, and, in addition, waves of a well defined
character. The latter would not exist by a steady supply of the energy;
still they help to jar and loosen the structure. If this really be the
case, then the ruby drop will emit relatively less visible and more
invisible waves than before. Thus it would seem that when a platinum
wire, for instance, is fused by currents alternating with extreme
rapidity, it emits at the point of fusion less light and more visible
radiation than it does when melted by a steady current, though the total
energy used up in the process of fusion is the same in both cases. Or,
to cite another example, a lamp filament is not capable of withstanding
as long with currents of extreme frequency as it does with steady
currents, assuming that it be worked at the same luminous intensity.
This means that for rapidly alternating currents the filament should be
shorter and thicker. The higher the frequency--that is, the greater the
departure from the steady flow--the worse it would be for the filament.
But if the truth of this remark were demonstrated, it would be erroneous
to conclude that such a refractory button as used in these bulbs would
be deteriorated quicker by currents of extremely high frequency than by
steady or low frequency currents. From experience I may say that just
the opposite holds good: the button withstands the bombardment better
with currents of very high frequency. But this is due to the fact that a
high frequency discharge passes through a rarefied gas with much greater
freedom than a steady or low frequency discharge, and this will mean
that with the former we can work with a lower potential or with a less
violent impact. As long, then, as the gas is of no consequence, a steady
or low frequency current is better; but as soon as the action of the gas
is desired and important, high frequencies are preferable.

In the course of these experiments a great many trials were made with
all kinds of carbon buttons. Electrodes made of ordinary carbon buttons
were decidedly more durable when the buttons were obtained by the
application of enormous pressure. Electrodes prepared by depositing
carbon in well known ways did not show up well; they blackened the globe
very quickly. From many experiences I conclude that lamp filaments
obtained in this manner can be advantageously used only with low
potentials and low frequency currents. Some kinds of carbon withstand so
well that, in order to bring them to the point of fusion, it is
necessary to employ very small buttons. In this case the observation is
rendered very difficult on account of the intense heat produced.
Nevertheless there can be no doubt that all kinds of carbon are fused
under the molecular bombardment, but the liquid state must be one of
great instability. Of all the bodies tried there were two which
withstood best--diamond and carborundum. These two showed up about
equally, but the latter was preferable for many reasons. As it is more
than likely that this body is not yet generally known, I will venture to
call your attention to it.

It has been recently produced by Mr. E. G. Acheson, of Monongahela City,
Pa., U. S. A. It is intended to replace ordinary diamond powder for
polishing precious stones, etc., and I have been informed that it
accomplishes this object quite successfully. I do not know why the name
"carborundum" has been given to it, unless there is something in the
process of its manufacture which justifies this selection. Through the
kindness of the inventor, I obtained a short while ago some samples
which I desired to test in regard to their qualities of phosphorescence
and capability of withstanding high degrees of heat.

Carborundum can be obtained in two forms--in the form of "crystals" and
of powder. The former appear to the naked eye dark colored, but are very
brilliant; the latter is of nearly the same color as ordinary diamond
powder, but very much finer. When viewed under a microscope the samples
of crystals given to me did not appear to have any definite form, but
rather resembled pieces of broken up egg coal of fine quality. The
majority were opaque, but there were some which were transparent and
colored. The crystals are a kind of carbon containing some impurities;
they are extremely hard, and withstand for a long time even an oxygen
blast. When the blast is directed against them they at first form a
cake of some compactness, probably in consequence of the fusion of
impurities they contain. The mass withstands for a very long time the
blast without further fusion; but a slow carrying off, or burning,
occurs, and, finally, a small quantity of a glass-like residue is left,
which, I suppose, is melted alumina. When compressed strongly they
conduct very well, but not as well as ordinary carbon. The powder, which
is obtained from the crystals in some way, is practically
non-conducting. It affords a magnificent polishing material for stones.

The time has been too short to make a satisfactory study of the
properties of this product, but enough experience has been gained in a
few weeks I have experimented upon it to say that it does possess some
remarkable properties in many respects. It withstands excessively high
degrees of heat, it is little deteriorated by molecular bombardment, and
it does not blacken the globe as ordinary carbon does. The only
difficulty which I have experienced in its use in connection with these
experiments was to find some binding material which would resist the
heat and the effect of the bombardment as successfully as carborundum
itself does.

I have here a number of bulbs which I have provided with buttons of
carborundum. To make such a button of carborundum crystals I proceed in
the following manner: I take an ordinary lamp filament and dip its point
in tar, or some other thick substance or paint which may be readily
carbonized. I next pass the point of the filament through the crystals,
and then hold it vertically over a hot plate. The tar softens and forms
a drop on the point of the filament, the crystals adhering to the
surface of the drop. By regulating the distance from the plate the tar
is slowly dried out and the button becomes solid. I then once more dip
the button in tar and hold it again over a plate until the tar is
evaporated, leaving only a hard mass which firmly binds the crystals.
When a larger button is required I repeat the process several times, and
I generally also cover the filament a certain distance below the button
with crystals. The button being mounted in a bulb, when a good vacuum
has been reached, first a weak and then a strong discharge is passed
through the bulb to carbonize the tar and expel all gases, and later it
is brought to a very intense incandescence.

When the powder is used I have found it best to proceed as follows: I
make a thick paint of carborundum and tar, and pass a lamp filament
through the paint. Taking then most of the paint off by rubbing the
filament against a piece of chamois leather, I hold it over a hot plate
until the tar evaporates and the coating becomes firm. I repeat this
process as many times as it is necessary to obtain a certain thickness
of coating. On the point of the coated filament I form a button in the
same manner.

There is no doubt that such a button--properly prepared under great
pressure--of carborundum, especially of powder of the best quality, will
withstand the effect of the bombardment fully as well as anything we
know. The difficulty is that the binding material gives way, and the
carborundum is slowly thrown off after some time. As it does not seem to
blacken the globe in the least, it might be found useful for coating the
filaments of ordinary incandescent lamps, and I think that it is even
possible to produce thin threads or sticks of carborundum which will
replace the ordinary filaments in an incandescent lamp. A carborundum
coating seems to be more durable than other coatings, not only because
the carborundum can withstand high degrees of heat, but also because it
seems to unite with the carbon better than any other material I have
tried. A coating of zirconia or any other oxide, for instance, is far
more quickly destroyed. I prepared buttons of diamond dust in the same
manner as of carborundum, and these came in durability nearest to those
prepared of carborundum, but the binding paste gave way much more
quickly in the diamond buttons; this, however, I attributed to the size
and irregularity of the grains of the diamond.

It was of interest to find whether carborundum possesses the quality of
phosphorescence. One is, of course, prepared to encounter two
difficulties: first, as regards the rough product, the "crystals," they
are good conducting, and it is a fact that conductors do not
phosphoresce; second, the powder, being exceedingly fine, would not be
apt to exhibit very prominently this quality, since we know that when
crystals, even such as diamond or ruby, are finely powdered, they lose
the property of phosphorescence to a considerable degree.

The question presents itself here, can a conductor phosphoresce? What is
there in such a body as a metal, for instance, that would deprive it of
the quality of phosphoresence, unless it is that property which
characterizes it as a conductor? For it is a fact that most of the
phosphorescent bodies lose that quality when they are sufficiently
heated to become more or less conducting. Then, if a metal be in a
large measure, or perhaps entirely, deprived of that property, it should
be capable of phosphoresence. Therefore it is quite possible that at
some extremely high frequency, when behaving practically as a
non-conductor, a metal or any other conductor might exhibit the quality
of phosphoresence, even though it be entirely incapable of
phosphorescing under the impact of a low-frequency discharge. There is,
however, another possible way how a conductor might at least _appear_ to
phosphoresce.

Considerable doubt still exists as to what really is phosphorescence,
and as to whether the various phenomena comprised under this head are
due to the same causes. Suppose that in an exhausted bulb, under the
molecular impact, the surface of a piece of metal or other conductor is
rendered strongly luminous, but at the same time it is found that it
remains comparatively cool, would not this luminosity be called
phosphorescence? Now such a result, theoretically at least, is possible,
for it is a mere question of potential or speed. Assume the potential of
the electrode, and consequently the speed of the projected atoms, to be
sufficiently high, the surface of the metal piece, against which the
atoms are projected, would be rendered highly incandescent, since the
process of heat generation would be incomparably faster than that of
radiating or conducting away from the surface of the collision. In the
eye of the observer a single impact of the atoms would cause an
instantaneous flash, but if the impacts were repeated with sufficient
rapidity, they would produce a continuous impression upon his retina. To
him then the surface of the metal would appear continuously incandescent
and of constant luminous intensity, while in reality the light would be
either intermittent, or at least changing periodically in intensity. The
metal piece would rise in temperature until equilibrium was
attained--that is, until the energy continuously radiated would equal
that intermittently supplied. But the supplied energy might under such
conditions not be sufficient to bring the body to any more than a very
moderate mean temperature, especially if the frequency of the atomic
impacts be very low--just enough that the fluctuation of the intensity
of the light emitted could not be detected by the eye. The body would
now, owing to the manner in which the energy is supplied, emit a strong
light, and yet be at a comparatively very low mean temperature. How
should the observer name the luminosity thus produced? Even if the
analysis of the light would teach him something definite, still he would
probably rank it under the phenomena of phosphorescence. It is
conceivable that in such a way both conducting and non-conducting bodies
may be maintained at a certain luminous intensity, but the energy
required would very greatly vary with the nature and properties of the
bodies.

These and some foregoing remarks of a speculative nature were made
merely to bring out curious features of alternate currents or electric
impulses. By their help we may cause a body to emit _more_ light, while
at a certain mean temperature, than it would emit if brought to that
temperature by a steady supply; and, again, we may bring a body to the
point of fusion, and cause it to emit _less_ light than when fused by
the application of energy in ordinary ways. It all depends on how we
supply the energy, and what kind of vibrations we set up; in one case
the vibrations are more, in the other less, adapted to affect our sense
of vision.

Some effects, which I had not observed before, obtained with carborundum
in the first trials, I attributed to phosphorescence, but in subsequent
experiments it appeared that it was devoid of that quality. The crystals
possess a noteworthy feature. In a bulb provided with a single electrode
in the shape of a small circular metal disc, for instance, at a certain
degree of exhaustion the electrode is covered with a milky film, which
is separated by a dark space from the glow filling the bulb. When the
metal disc is covered with carborundum crystals, the film is far more
intense, and snow-white. This I found later to be merely an effect of
the bright surface of the crystals, for when an aluminum electrode was
highly polished, it exhibited more or less the same phenomenon. I made a
number of experiments with the samples of crystals obtained, principally
because it would have been of special interest to find that they are
capable of phosphorescence, on account of their being conducting. I
could not produce phosphorescence distinctly, but I must remark that a
decisive opinion cannot be formed until other experimenters have gone
over the same ground.

The powder behaved in some experiments as though it contained alumina,
but it did not exhibit with sufficient distinctness the red of the
latter. Its dead color brightens considerably under the molecular
impact, but I am now convinced it does not phosphoresce. Still, the
tests with the powder are not conclusive, because powdered carborundum
probably does not behave like a phosphorescent sulphide, for example,
which could be finely powdered without impairing the phosphorescence,
but rather like powdered ruby or diamond, and therefore it would be
necessary, in order to make a decisive test, to obtain it in a large
lump and polish up the surface.

If the carborundum proves useful in connection with these and similar
experiments, its chief value will be found in the production of
coatings, thin conductors, buttons, or other electrodes capable of
withstanding extremely high degrees of heat.

The production of a small electrode, capable of withstanding enormous
temperatures, I regard as of the greatest importance in the manufacture
of light. It would enable us to obtain, by means of currents of very
high frequencies, certainly 20 times, if not more, the quantity of light
which is obtained in the present incandescent lamp by the same
expenditure of energy. This estimate may appear to many exaggerated, but
in reality I think it is far from being so. As this statement might be
misunderstood, I think it is necessary to expose clearly the problem
with which, in this line of work, we are confronted, and the manner in
which, in my opinion, a solution will be arrived at.

Any one who begins a study of the problem will be apt to think that what
is wanted in a lamp with an electrode is a very high degree of
incandescence of the electrode. There he will be mistaken. The high
incandescence of the button is a necessary evil, but what is really
wanted is the high incandescence of the gas surrounding the button. In
other words, the problem in such a lamp is to bring a mass of gas to the
highest possible incandescence. The higher the incandescence, the
quicker the mean vibration, the greater is the economy of the light
production. But to maintain a mass of gas at a high degree of
incandescence in a glass vessel, it will always be necessary to keep the
incandescent mass away from the glass; that is, to confine it as much as
possible to the central portion of the globe.

In one of the experiments this evening a brush was produced at the end
of a wire. The brush was a flame, a source of heat and light. It did not
emit much perceptible heat, nor did it glow with an intense light; but
is it the less a flame because it does not scorch my hand? Is it the
less a flame because it does not hurt my eyes by its brilliancy? The
problem is precisely to produce in the bulb such a flame, much smaller
in size, but incomparably more powerful. Were there means at hand for
producing electric impulses of a sufficiently high frequency, and for
transmitting them, the bulb could be done away with, unless it were used
to protect the electrode, or to economize the energy by confining the
heat. But as such means are not at disposal, it becomes necessary to
place the terminal in the bulb and rarefy the air in the same. This is
done merely to enable the apparatus to perform the work which it is not
capable of performing at ordinary air pressure. In the bulb we are able
to intensify the action to any degree--so far that the brush emits a
powerful light.

The intensity of the light emitted depends principally on the frequency
and potential of the impulses, and on the electric density on the
surface of the electrode. It is of the greatest importance to employ the
smallest possible button, in order to push the density very far. Under
the violent impact of the molecules of the gas surrounding it, the small
electrode is of course brought to an extremely high temperature, but
around it is a mass of highly incandescent gas, a flame photosphere,
many hundred times the volume of the electrode. With a diamond,
carborundum or zirconia button the photosphere can be as much as one
thousand times the volume of the button. Without much reflection one
would think that in pushing so far the incandescence of the electrode it
would be instantly volatilized. But after a careful consideration one
would find that, theoretically, it should not occur, and in this
fact--which, moreover, is experimentally demonstrated--lies principally
the future value of such a lamp.

At first, when the bombardment begins, most of the work is performed on
the surface of the button, but when a highly conducting photosphere is
formed the button is comparatively relieved. The higher the
incandescence of the photosphere, the more it approaches in conductivity
to that of the electrode, and the more, therefore, the solid and the gas
form one conducting body. The consequence is that the further the
incandescence is forced the more work, comparatively, is performed on
the gas, and the less on the electrode. The formation of a powerful
photosphere is consequently the very means for protecting the electrode.
This protection, of course, is a relative one, and it should not be
thought that by pushing the incandescence higher the electrode is
actually less deteriorated. Still, theoretically, with extreme
frequencies, this result must be reached, but probably at a temperature
too high for most of the refractory bodies known. Given, then, an
electrode which can withstand to a very high limit the effect of the
bombardment and outward strain, it would be safe, no matter how much it
was forced beyond that limit. In an incandescent lamp quite different
considerations apply. There the gas is not at all concerned; the whole
of the work is performed on the filament; and the life of the lamp
diminishes so rapidly with the increase of the degree of incandescence
that economical reasons compel us to work it at a low incandescence. But
if an incandescent lamp is operated with currents of very high
frequency, the action of the gas cannot be neglected, and the rules for
the most economical working must be considerably modified.

In order to bring such a lamp with one or two electrodes to a great
perfection, it is necessary to employ impulses of very high frequency.
The high frequency secures, among others, two chief advantages, which
have a most important bearing upon the economy of the light production.
First, the deterioration of the electrode is reduced by reason of the
fact that we employ a great many small impacts, instead of a few violent
ones, which quickly shatter the structure; secondly, the formation of a
large photosphere is facilitated.

In order to reduce the deterioration of the electrode to the minimum, it
is desirable that the vibration be harmonic, for any suddenness hastens
the process of destruction. An electrode lasts much longer when kept at
incandescence by currents, or impulses, obtained from a high frequency
alternator, which rise and fall more or less harmonically, than by
impulses obtained from a disruptive discharge coil. In the latter case
there is no doubt that most of the damage is done by the fundamental
sudden discharges.

One of the elements of loss in such a lamp is the bombardment of the
globe. As the potential is very high, the molecules are projected with
great speed; they strike the glass, and usually excite a strong
phosphorescence. The effect produced is very pretty, but for economical
reasons it would be perhaps preferable to prevent, or at least reduce to
a minimum, the bombardment against the globe, as in such case it is, as
a rule, not the object to excite phosphorescence, and as some loss of
energy results from the bombardment. This loss in the bulb is
principally dependent on the potential of the impulses and on the
electric density on the surface of the electrode. In employing very high
frequencies the loss of energy by the bombardment is greatly reduced,
for, first, the potential needed to perform a given amount of work is
much smaller; and, secondly, by producing a highly conducting
photosphere around the electrode, the same result is obtained as though
the electrode were much larger, which is equivalent to a smaller
electric density. But be it by the diminution of the maximum potential
or of the density, the gain is effected in the same manner, namely, by
avoiding violent shocks, which strain the glass much beyond its limit of
elasticity. If the frequency could be brought high enough, the loss due
to the imperfect elasticity of the glass would be entirely negligible.
The loss due to bombardment of the globe may, however, be reduced by
using two electrodes instead of one. In such case each of the electrodes
may be connected to one of the terminals; or else, if it is preferable
to use only one wire, one electrode may be connected to one terminal and
the other to the ground or to an insulated body of some surface, as, for
instance, a shade on the lamp. In the latter case, unless some judgment
is used, one of the electrodes might glow more intensely than the other.

But on the whole I find it preferable, when using such high frequencies,
to employ only one electrode and one connecting wire. I am convinced
that the illuminating device of the near future will not require for its
operation more than one lead, and, at any rate, it will have no
leading-in wire, since the energy required can be as well transmitted
through the glass. In experimental bulbs the leading-in wire is not
generally used on account of convenience, as in employing condenser
coatings in the manner indicated in Fig. 151, for example, there is some
difficulty in fitting the parts, but these difficulties would not exist
if a great many bulbs were manufactured; otherwise the energy can be
conveyed through the glass as well as through a wire, and with these
high frequencies the losses are very small. Such illustrating devices
will necessarily involve the use of very high potentials, and this, in
the eyes of practical men, might be an objectionable feature. Yet, in
reality, high potentials are not objectionable--certainly not in the
least so far as the safety of the devices is concerned.

There are two ways of rendering an electric appliance safe. One is to
use low potentials, the other is to determine the dimensions of the
apparatus so that it is safe, no matter how high a potential is used. Of
the two, the latter seems to me the better way, for then the safety is
absolute, unaffected by any possible combination of circumstances which
might render even a low-potential appliance dangerous to life and
property. But the practical conditions require not only the judicious
determination of the dimensions of the apparatus; they likewise
necessitate the employment of energy of the proper kind. It is easy, for
instance, to construct a transformer capable of giving, when operated
from an ordinary alternate current machine of low tension, say 50,000
volts, which might be required to light a highly exhausted
phosphorescent tube, so that, in spite of the high potential, it is
perfectly safe, the shock from it producing no inconvenience. Still such
a transformer would be expensive, and in itself inefficient; and,
besides, what energy was obtained from it would not be economically used
for the production of light. The economy demands the employment of
energy in the form of extremely rapid vibrations. The problem of
producing light has been likened to that of maintaining a certain
high-pitch note by means of a bell. It should be said a _barely audible_
note; and even these words would not express it, so wonderful is the
sensitiveness of the eye. We may deliver powerful blows at long
intervals, waste a good deal of energy, and still not get what we want;
or we may keep up the note by delivering frequent taps, and get nearer
to the object sought by the expenditure of much less energy. In the
production of light, as far as the illuminating device is concerned,
there can be only one rule--that is, to use as high frequencies as can
be obtained; but the means for the production and conveyance of impulses
of such character impose, at present at least, great limitations. Once
it is decided to use very high frequencies, the return wire becomes
unnecessary, and all the appliances are simplified. By the use of
obvious means the same result is obtained as though the return wire were
used. It is sufficient for this purpose to bring in contact with the
bulb, or merely in the vicinity of the same, an insulated body of some
surface. The surface need, of course, be the smaller, the higher the
frequency and potential used, and necessarily, also, the higher the
economy of the lamp or other device.

This plan of working has been resorted to on several occasions this
evening. So, for instance, when the incandescence of a button was
produced by grasping the bulb with the hand, the body of the
experimenter merely served to intensify the action. The bulb used was
similar to that illustrated in Fig. 148, and the coil was excited to a
small potential, not sufficient to bring the button to incandescence
when the bulb was hanging from the wire; and incidentally, in order to
perform the experiment in a more suitable manner, the button was taken
so large that a perceptible time had to elapse before, upon grasping the
bulb, it could be rendered incandescent. The contact with the bulb was,
of course, quite unnecessary. It is easy, by using a rather large bulb
with an exceedingly small electrode, to adjust the conditions so that
the latter is brought to bright incandescence by the mere approach of
the experimenter within a few feet of the bulb, and that the
incandescence subsides upon his receding.

[Illustration: FIG. 153.]

[Illustration: FIG. 154.]

In another experiment, when phosphorescence was excited, a similar bulb
was used. Here again, originally, the potential was not sufficient to
excite phosphorescence until the action was intensified--in this case,
however, to present a different feature, by touching the socket with a
metallic object held in the hand. The electrode in the bulb was a carbon
button so large that it could not be brought to incandescence, and
thereby spoil the effect produced by phosphorescence.

Again, in another of the early experiments, a bulb was used, as
illustrated in Fig. 141. In this instance, by touching the bulb with one
or two fingers, one or two shadows of the stem inside were projected
against the glass, the touch of the finger producing the same results as
the application of an external negative electrode under ordinary
circumstances.

In all these experiments the action was intensified by augmenting the
capacity at the end of the lead connected to the terminal. As a rule, it
is not necessary to resort to such means, and would be quite unnecessary
with still higher frequencies; but when it _is_ desired, the bulb, or
tube, can be easily adapted to the purpose.

In Fig. 153, for example, an experimental bulb, L, is shown, which
is provided with a neck, _n_, on the top, for the application of an
external tinfoil coating, which may be connected to a body of larger
surface. Such a lamp as illustrated in Fig. 154 may also be lighted by
connecting the tinfoil coating on the neck _n_ to the terminal, and the
leading-in wire, _w_, to an insulated plate. If the bulb stands in a
socket upright, as shown in the cut, a shade of conducting material may
be slipped in the neck, _n_, and the action thus magnified.

A more perfected arrangement used in some of these bulbs is illustrated
in Fig. 155. In this case the construction of the bulb is as shown and
described before, when reference was made to Fig. 148. A zinc sheet, Z,
with a tubular extension, T, is applied over the metallic socket, S.
The bulb hangs downward from the terminal, _t_, the zinc sheet, Z,
performing the double office of intensifier and reflector. The reflector
is separated from the terminal, _t_, by an extension of the insulating
plug, P.

A similar disposition with a phosphorescent tube is illustrated in
Fig. 156. The tube, T, is prepared from two short tubes of different
diameter, which are sealed on the ends. On the lower end is placed an
inside conducting coating, C, which connects to the wire _w_. The wire
has a hook on the upper end for suspension, and passes through the
centre of the inside tube, which is filled with some good and tightly
packed insulator. On the outside of the upper end of the tube, T, is
another conducting coating, C_{1}, upon which is slipped a metallic
reflector Z, which should be separated by a thick insulation from the
end of wire _w_.

The economical use of such a reflector or intensifier would require that
all energy supplied to an air condenser should be recoverable, or, in
other words, that there should not be any losses, neither in the
gaseous medium nor through its action elsewhere. This is far from being
so, but, fortunately, the losses may be reduced to anything desired. A
few remarks are necessary on this subject, in order to make the
experiences gathered in the course of these investigations perfectly
clear.

[Illustration: FIG. 155.]

Suppose a small helix with many well insulated turns, as in experiment
Fig. 146, has one of its ends connected to one of the terminals of the
induction coil, and the other to a metal plate, or, for the sake of
simplicity, a sphere, insulated in space. When the coil is set to work,
the potential of the sphere is alternated, and a small helix now behaves
as though its free end were connected to the other terminal of the
induction coil. If an iron rod be held within a small helix, it is
quickly brought to a high temperature, indicating the passage of a
strong current through the helix. How does the insulated sphere act in
this case? It can be a condenser, storing and returning the energy
supplied to it, or it can be a mere sink of energy, and the conditions
of the experiment determine whether it is rather one than the other. The
sphere being charged to a high potential, it acts inductively upon the
surrounding air, or whatever gaseous medium there might be. The
molecules, or atoms, which are near the sphere, are of course more
attracted, and move through a greater distance than the farther ones.
When the nearest molecules strike the sphere, they are repelled, and
collisions occur at all distances within the inductive action of the
sphere. It is now clear that, if the potential be steady, but little
loss of energy can be caused in this way, for the molecules which are
nearest to the sphere, having had an additional charge imparted to them
by contact, are not attracted until they have parted, if not with all,
at least with most of the additional charge, which can be accomplished
only after a great many collisions. From the fact, that with a steady
potential there is but little loss in dry air, one must come to such a
conclusion. When the potential of a sphere, instead of being steady, is
alternating, the conditions are entirely different. In this case a
rhythmical bombardment occurs, no matter whether the molecules, after
coming in contact with the sphere, lose the imparted charge or not; what
is more, if the charge is not lost, the impacts are only the more
violent. Still, if the frequency of the impulses be very small, the loss
caused by the impacts and collisions would not be serious, unless the
potential were excessive. But when extremely high frequencies and more
or less high potentials are used, the loss may very great. The total
energy lost per unit of time is proportionate to the product of the
number of impacts per second, or the frequency and the energy lost in
each impact. But the energy of an impact must be proportionate to the
square of the electric density of the sphere, since the charge imparted
to the molecule is proportionate to that density. I conclude from this
that the total energy lost must be proportionate to the product of the
frequency and the square of the electric density; but this law needs
experimental confirmation. Assuming the preceding considerations to be
true, then, by rapidly alternating the potential of a body immersed in
an insulating gaseous medium, any amount of energy may be dissipated
into space. Most of that energy then, I believe, is not dissipated in
the form of long ether waves, propagated to considerable distance, as is
thought most generally, but is consumed--in the case of an insulated
sphere, for example--in impact and collisional losses--that is, heat
vibrations--on the surface and in the vicinity of the sphere. To reduce
the dissipation, it is necessary to work with a small electric
density--the smaller, the higher the frequency.

[Illustration: FIG. 156.]

But since, on the assumption before made, the loss is diminished with
the square of the density, and since currents of very high frequencies
involve considerable waste when transmitted through conductors, it
follows that, on the whole, it is better to employ one wire than two.
Therefore, if motors, lamps, or devices of any kind are perfected,
capable of being advantageously operated by currents of extremely high
frequency, economical reasons will make it advisable to use only one
wire, especially if the distances are great.

When energy is absorbed in a condenser, the same behaves as though its
capacity were increased. Absorption always exists more or less, but
generally it is small and of no consequence as long as the frequencies
are not very great. In using extremely high frequencies, and,
necessarily in such case, also high potentials, the absorption--or, what
is here meant more particularly by this term, the loss of energy due to
the presence of a gaseous medium--is an important factor to be
considered, as the energy absorbed in the air condenser may be any
fraction of the supplied energy. This would seem to make it very
difficult to tell from the measured or computed capacity of an air
condenser its actual capacity or vibration period, especially if the
condenser is of very small surface and is charged to a very high
potential. As many important results are dependent upon the correctness
of the estimation of the vibration period, this subject demands the most
careful scrutiny of other investigators. To reduce the probable error as
much as possible in experiments of the kind alluded to, it is advisable
to use spheres or plates of large surface, so as to make the density
exceedingly small. Otherwise, when it is practicable, an oil condenser
should be used in preference. In oil or other liquid dielectrics there
are seemingly no such losses as in gaseous media. It being impossible to
exclude entirely the gas in condensers with solid dielectrics, such
condensers should be immersed in oil, for economical reasons, if nothing
else; they can then be strained to the utmost, and will remain cool. In
Leyden jars the loss due to air is comparatively small, as the tinfoil
coatings are large, close together, and the charged surfaces not
directly exposed; but when the potentials are very high, the loss may be
more or less considerable at, or near, the upper edge of the foil, where
the air is principally acted upon. If the jar be immersed in boiled-out
oil, it will be capable of performing four times the amount of work
which it can for any length of time when used in the ordinary way, and
the loss will be inappreciable.

It should not be thought that the loss in heat in an air condenser is
necessarily associated with the formation of _visible_ streams or
brushes. If a small electrode, inclosed in an unexhausted bulb, is
connected to one of the terminals of the coil, streams can be seen to
issue from the electrode, and the air in the bulb is heated; if instead
of a small electrode a large sphere is inclosed in the bulb, no streams
are observed, still the air is heated.

Nor should it be thought that the temperature of an air condenser would
give even an approximate idea of the loss in heat incurred, as in such
case heat must be given off much more quickly, since there is, in
addition to the ordinary radiation, a very active carrying away of heat
by independent carriers going on, and since not only the apparatus, but
the air at some distance from it is heated in consequence of the
collisions which must occur.

Owing to this, in experiments with such a coil, a rise of temperature
can be distinctly observed only when the body connected to the coil is
very small. But with apparatus on a larger scale, even a body of
considerable bulk would be heated, as, for instance, the body of a
person; and I think that skilled physicians might make observations of
utility in such experiments, which, if the apparatus were judiciously
designed, would not present the slightest danger.

A question of some interest, principally to meteorologists, presents
itself here. How does the earth behave? The earth is an air condenser,
but is it a perfect or a very imperfect one--a mere sink of energy?
There can be little doubt that to such small disturbance as might be
caused in an experiment, the earth behaves as an almost perfect
condenser. But it might be different when its charge is set in vibration
by some sudden disturbance occurring in the heavens. In such case, as
before stated, probably only little of the energy of the vibrations set
up would be lost into space in the form of long ether radiations, but
most of the energy, I think, would spend itself in molecular impacts and
collisions, and pass off into space in the form of short heat, and
possibly light, waves. As both the frequency of the vibrations of the
charge and the potential are in all probability excessive, the energy
converted into heat may be considerable. Since the density must be
unevenly distributed, either in consequence of the irregularity of the
earth's surface, or on account of the condition of the atmosphere in
various places, the effect produced would accordingly vary from place to
place. Considerable variations in the temperature and pressure of the
atmosphere may in this manner be caused at any point of the surface of
the earth. The variations may be gradual or very sudden, according to
the nature of the general disturbance, and may produce rain and storms,
or locally modify the weather in any way.

From the remarks before made, one may see what an important factor of
loss the air in the neighborhood of a charged surface becomes when the
electric density is great and the frequency of the impulses excessive.
But the action, as explained, implies that the air is insulating--that
is, that it is composed of independent carriers immersed in an
insulating medium. This is the case only when the air is at something
like ordinary or greater, or at extremely small, pressure. When the air
is slightly rarefied and conducting, then true conduction losses occur
also. In such case, of course, considerable energy may be dissipated
into space even with a steady potential, or with impulses of low
frequency, if the density is very great.

When the gas is at very low pressure, an electrode is heated more
because higher speeds can be reached. If the gas around the electrode is
strongly compressed, the displacements, and consequently the speeds, are
very small, and the heating is insignificant. But if in such case the
frequency could be sufficiently increased, the electrode would be
brought to a high temperature as well as if the gas were at very low
pressure; in fact, exhausting the bulb is only necessary because we
cannot produce, (and possibly not convey) currents of the required
frequency.

Returning to the subject of electrode lamps, it is obviously of
advantage in such a lamp to confine as much as possible the heat to the
electrode by preventing the circulation of the gas in the bulb. If a
very small bulb be taken, it would confine the heat better than a large
one, but it might not be of sufficient capacity to be operated from the
coil, or, if so, the glass might get too hot. A simple way to improve in
this direction is to employ a globe of the required size, but to place a
small bulb, the diameter of which is properly estimated, over the
refractory button contained in the globe. This arrangement is
illustrated in Fig. 157.

[Illustration: FIG. 157.]

[Illustration: FIG. 158.]

The globe L has in this case a large neck _n_, allowing the small bulb
_b_ to slip through. Otherwise the construction is the same as shown in
Fig. 147, for example. The small bulb is conveniently supported upon the
stem _s_, carrying the refractory button _m_. It is separated from the
aluminum tube _a_ by several layers of mica M, in order to prevent the
cracking of the neck by the rapid heating of the aluminum tube upon a
sudden turning on of the current. The inside bulb should be as small as
possible when it is desired to obtain light only by incandescence of the
electrode. If it is desired to produce phosphorescence, the bulb should
be larger, else it would be apt to get too hot, and the phosphorescence
would cease. In this arrangement usually only the small bulb shows
phosphorescence, as there is practically no bombardment against the
outer globe. In some of these bulbs constructed as illustrated in Fig.
157, the small tube was coated with phosphorescent paint, and beautiful
effects were obtained. Instead of making the inside bulb large, in order
to avoid undue heating, it answers the purpose to make the electrode _m_
larger. In this case the bombardment is weakened by reason of the
smaller electric density.

Many bulbs were constructed on the plan illustrated in Fig. 158. Here a
small bulb _b_, containing the refractory button _m_, upon being
exhausted to a very high degree was sealed in a large globe L, which was
then moderately exhausted and sealed off. The principal advantage of
this construction was that it allowed of reaching extremely high vacua,
and, at the same time of using a large bulb. It was found, in the course
of experiments with bulbs such as illustrated in Fig. 158, that it was
well to make the stem _s_, near the seal at _e_, very thick, and the
leading-in wire _w_ thin, as it occurred sometimes that the stem at _e_
was heated and the bulb was cracked. Often the outer globe L was
exhausted only just enough to allow the discharge to pass through, and
the space between the bulbs appeared crimson, producing a curious
effect. In some cases, when the exhaustion in globe L was very low, and
the air good conducting, it was found necessary, in order to bring the
button _m_ to high incandescence, to place, preferably on the upper part
of the neck of the globe, a tinfoil coating which was connected to an
insulated body, to the ground, or to the other terminal of the coil, as
the highly conducting air weakened the effect somewhat, probably by
being acted upon inductively from the wire _w_, where it entered the
bulb at _e_. Another difficulty--which, however, is always present when
the refractory button is mounted in a very small bulb--existed in the
construction illustrated in Fig. 158, namely, the vacuum in the bulb _b_
would be impaired in a comparatively short time.

The chief idea in the two last described constructions was to confine
the heat to the central portion of the globe by preventing the exchange
of air. An advantage is secured, but owing to the heating of the inside
bulb and slow evaporation of the glass, the vacuum is hard to maintain,
even if the construction illustrated in Fig. 157 be chosen, in which
both bulbs communicate.

But by far the better way--the ideal way--would be to reach sufficiently
high frequencies. The higher the frequency, the slower would be the
exchange of the air, and I think that a frequency may be reached, at
which there would be no exchange whatever of the air molecules around
the terminal. We would then produce a flame in which there would be no
carrying away of material, and a queer flame it would be, for it would
be rigid! With such high frequencies the inertia of the particles would
come into play. As the brush, or flame, would gain rigidity in virtue of
the inertia of the particles, the exchange of the latter would be
prevented. This would necessarily occur, for, the number of impulses
being augmented, the potential energy of each would diminish, so that
finally only atomic vibrations could be set up, and the motion of
translation through measurable space would cease. Thus an ordinary gas
burner connected to a source of rapidly alternating potential might have
its efficiency augmented to a certain limit, and this for two
reasons--because of the additional vibration imparted, and because of a
slowing down of the process of carrying off. But the renewal being
rendered difficult, a renewal being necessary to maintain the _burner_,
a continued increase of the frequency of the impulses, assuming they
could be transmitted to and impressed upon the flame, would result in
the "extinction" of the latter, meaning by this term only the cessation
of the chemical process.

I think, however, that in the case of an electrode immersed in a fluid
insulating medium, and surrounded by independent carriers of electric
charges, which can be acted upon inductively, a sufficient high
frequency of the impulses would probably result in a gravitation of the
gas all around toward the electrode. For this it would be only necessary
to assume that the independent bodies are irregularly shaped; they would
then turn toward the electrode their side of the greatest electric
density, and this would be a position in which the fluid resistance to
approach would be smaller than that offered to the receding.

The general opinion, I do not doubt, is that it is out of the question
to reach any such frequencies as might--assuming some of the views
before expressed to be true--produce any of the results which I have
pointed out as mere possibilities. This may be so, but in the course of
these investigations, from the observation of many phenomena, I have
gained the conviction that these frequencies would be much lower than
one is apt to estimate at first. In a flame we set up light vibrations
by causing molecules, or atoms, to collide. But what is the ratio of the
frequency of the collisions and that of the vibrations set up? Certainly
it must be incomparably smaller than that of the strokes of the bell and
the sound vibrations, or that of the discharges and the oscillations of
the condenser. We may cause the molecules of the gas to collide by the
use of alternate electric impulses of high frequency, and so we may
imitate the process in a flame; and from experiments with frequencies
which we are now able to obtain, I think that the result is producible
with impulses which are transmissible through a conductor.

In connection with thoughts of a similar nature, it appeared to me of
great interest to demonstrate the rigidity of a vibrating gaseous
column. Although with such low frequencies as, say 10,000 per second,
which I was able to obtain without difficulty from a specially
constructed alternator, the task looked discouraging at first, I made a
series of experiments. The trials with air at ordinary pressure led to
no result, but with air moderately rarefied I obtain what I think to be
an unmistakable experimental evidence of the property sought for. As a
result of this kind might lead able investigators to conclusions of
importance, I will describe one of the experiments performed.

It is well known that when a tube is slightly exhausted, the discharge
may be passed through it in the form of a thin luminous thread. When
produced with currents of low frequency, obtained from a coil operated
as usual, this thread is inert. If a magnet be approached to it, the
part near the same is attracted or repelled, according to the direction
of the lines of force of the magnet. It occurred to me that if such a
thread would be produced with currents of very high frequency, it should
be more or less rigid, and as it was visible it could be easily studied.
Accordingly I prepared a tube about one inch in diameter and one metre
long, with outside coating at each end. The tube was exhausted to a
point at which, by a little working, the thread discharge could be
obtained. It must be remarked here that the general aspect of the tube,
and the degree of exhaustion, are quite other than when ordinary low
frequency currents are used. As it was found preferable to work with one
terminal, the tube prepared was suspended from the end of a wire
connected to the terminal, the tinfoil coating being connected to the
wire, and to the lower coating sometimes a small insulated plate was
attached. When the thread was formed, it extended through the upper part
of the tube and lost itself in the lower end. If it possessed rigidity
it resembled, not exactly an elastic cord stretched tight between two
supports, but a cord suspended from a height with a small weight
attached at the end. When the finger or a small magnet was approached to
the upper end of the luminous thread, it could be brought locally out of
position by electrostatic or magnetic action; and when the disturbing
object was very quickly removed, an analogous result was produced, as
though a suspended cord would be displaced and quickly released near the
point of suspension. In doing this the luminous thread was set in
vibration, and two very sharply marked nodes, and a third indistinct
one, were formed. The vibration, once set up, continued for fully eight
minutes, dying gradually out. The speed of the vibration often varied
perceptibly, and it could be observed that the electrostatic attraction
of the glass affected the vibrating thread; but it was clear that the
electrostatic action was not the cause of the vibration, for the thread
was most generally stationary, and could always be set in vibration by
passing the finger quickly near the upper part of the tube. With a
magnet the thread could be split in two and both parts vibrated. By
approaching the hand to the lower coating of the tube, or insulation
plate if attached, the vibration was quickened; also, as far as I could
see, by raising the potential or frequency. Thus, either increasing the
frequency or passing a stronger discharge of the same frequency
corresponded to a tightening of the cord. I did not obtain any
experimental evidence with condenser discharges. A luminous band excited
in the bulb by repeated discharges of a Leyden jar must possess
rigidity, and if deformed and suddenly released, should vibrate. But
probably the amount of vibrating matter is so small that in spite of the
extreme speed, the inertia cannot prominently assert itself. Besides,
the observation in such a case is rendered extremely difficult on
account of the fundamental vibration.

The demonstration of the fact--which still needs better experimental
confirmation--that a vibrating gaseous column possesses rigidity, might
greatly modify the views of thinkers. When with low frequencies and
insignificant potentials indications of that property may be noted, how
must a gaseous medium behave under the influence of enormous
electrostatic stresses which may be active in the interstellar space,
and which may alternate with inconceivable rapidity? The existence of
such an electrostatic, rhythmically throbbing force--of a vibrating
electrostatic field--would show a possible way how solids might have
formed from the ultra-gaseous uterus, and how transverse and all kinds
of vibrations may be transmitted through a gaseous medium filling all
space. Then, ether might be a true fluid, devoid of rigidity, and at
rest, it being merely necessary as a connecting link to enable
interaction. What determines the rigidity of a body? It must be the
speed and the amount of motive matter. In a gas the speed maybe
considerable, but the density is exceedingly small; in a liquid the
speed would be likely to be small, though the density may be
considerable; and in both cases the inertia resistance offered to
displacement is practically _nil_. But place a gaseous (or liquid)
column in an intense, rapidly alternating electrostatic field, set the
particles vibrating with enormous speeds, then the inertia resistance
asserts itself. A body might move with more or less freedom through the
vibrating mass, but as a whole it would be rigid.

There is a subject which I must mention in connection with these
experiments: it is that of high vacua. This is a subject, the study of
which is not only interesting, but useful, for it may lead to results of
great practical importance. In commercial apparatus, such as
incandescent lamps, operated from ordinary systems of distribution, a
much higher vacuum than is obtained at present would not secure a very
great advantage. In such a case the work is performed on the filament,
and the gas is little concerned; the improvement, therefore, would be
but trifling. But when we begin to use very high frequencies and
potentials, the action of the gas becomes all important, and the degree
of exhaustion materially modifies the results. As long as ordinary
coils, even very large ones, were used, the study of the subject was
limited, because just at a point when it became most interesting it had
to be interrupted on account of the "non-striking" vacuum being reached.
But at present we are able to obtain from a small disruptive discharge
coil potentials much higher than even the largest coil was capable of
giving, and, what is more, we can make the potential alternate with
great rapidity. Both of these results enable us now to pass a luminous
discharge through almost any vacua obtainable, and the field of our
investigations is greatly extended. Think we as we may, of all the
possible directions to develop a practical illuminant, the line of high
vacua seems to be the most promising at present. But to reach extreme
vacua the appliances must be much more improved, and ultimate perfection
will not be attained until we shall have discharged the mechanical and
perfected an _electrical_ vacuum pump. Molecules and atoms can be thrown
out of a bulb under the action of an enormous potential: _this_ will be
the principle of the vacuum pump of the future. For the present, we must
secure the best results we can with mechanical appliances. In this
respect, it might not be out of the way to say a few words about the
method of, and apparatus for, producing excessively high degrees of
exhaustion of which I have availed myself in the course of these
investigations. It is very probable that other experimenters have used
similar arrangements; but as it is possible that there may be an item of
interest in their description, a few remarks, which will render this
investigation more complete, might be permitted.

[Illustration: FIG. 159.]

The apparatus is illustrated in a drawing shown in Fig. 159. S
represents a Sprengel pump, which has been specially constructed to
better suit the work required. The stop-cock which is usually employed
has been omitted, and instead of it a hollow stopper _s_ has been fitted
in the neck of the reservoir R. This stopper has a small hole _h_,
through which the mercury descends; the size of the outlet _o_ being
properly determined with respect to the section of the fall tube _t_,
which is sealed to the reservoir instead of being connected to it in the
usual manner. This arrangement overcomes the imperfections and troubles
which often arise from the use of the stopcock on the reservoir and the
connections of the latter with the fall tube.

The pump is connected through a U-shaped tube _t_ to a very large
reservoir R_{1}. Especial care was taken in fitting the grinding
surfaces of the stoppers p and p_{1}, and both of these and the mercury
caps above them were made exceptionally long. After the U-shaped tube
was fitted and put in place, it was heated, so as to soften and take
off the strain resulting from imperfect fitting. The U-shaped tube was
provided with a stopcock C, and two ground connections g and g_{1},--one
for a small bulb _b_, usually containing caustic potash, and the other
for the receiver _r_, to be exhausted.

The reservoir R_{1}, was connected by means of a rubber tube to a
slightly larger reservoir R_{2}, each of the two reservoirs being
provided with a stopcock C_{1} and C_{2}, respectively. The reservoir
R_{2} could be raised and lowered by a wheel and rack, and the range of
its motion was so determined that when it was filled with mercury and
the stopcock C_{2} closed, so as to form a Torricellian vacuum in it
when raised, it could be lifted so high that the reservoir R_{1} would
stand a little above stopcock C_{1}; and when this stopcock was closed
and the reservoir R_{2} descended, so as to form a Torricellian vacuum
in reservoir R_{1}, it could be lowered so far as to completely empty
the latter, the mercury filling the reservoir R_{2} up to a little above
stopcock C_{2}.

The capacity of the pump and of the connections was taken as small as
possible relatively to the volume of reservoir, R_{1}, since, of course,
the degree of exhaustion depended upon the ratio of these quantities.

With this apparatus I combined the usual means indicated by former
experiments for the production of very high vacua. In most of the
experiments it was most convenient to use caustic potash. I may venture
to say, in regard to its use, that much time is saved and a more perfect
action of the pump insured by fusing and boiling the potash as soon as,
or even before, the pump settles down. If this course is not followed,
the sticks, as ordinarily employed, may give off moisture at a certain
very slow rate, and the pump may work for many hours without reaching a
very high vacuum. The potash was heated either by a spirit lamp or by
passing a discharge through it, or by passing a current through a wire
contained in it. The advantage in the latter case was that the heating
could be more rapidly repeated.

Generally the process of exhaustion was the following:--At the start,
the stop-cocks C and C_{1} being open, and all other connections closed,
the reservoir R_{2} was raised so far that the mercury filled the
reservoir R_{1} and a part of the narrow connecting U-shaped tube.
When the pump was set to work, the mercury would, of course, quickly
rise in the tube, and reservoir R_{2} was lowered, the experimenter
keeping the mercury at about the same level. The reservoir R_{2} was
balanced by a long spring which facilitated the operation, and the
friction of the parts was generally sufficient to keep it in almost any
position. When the Sprengel pump had done its work, the reservoir R_{2}
was further lowered and the mercury descended in R_{1} and filled R_{2},
whereupon stopcock C_{2} was closed. The air adhering to the walls of
R_{1} and that absorbed by the mercury was carried off, and to free the
mercury of all air the reservoir R_{2} was for a long time worked up and
down. During this process some air, which would gather below stopcock
C_{2}, was expelled from R_{2} by lowering it far enough and opening the
stopcock, closing the latter again before raising the reservoir. When
all the air had been expelled from the mercury, and no air would gather
in R_{2} when it was lowered, the caustic potash was resorted to. The
reservoir R_{2} was now again raised until the mercury in R_{1}, stood
above stopcock C_{1}. The caustic potash was fused and boiled, and
moisture partly carried off by the pump and partly re-absorbed; and this
process of heating and cooling was repeated many times, and each time,
upon the moisture being absorbed or carried off, the reservoir R_{2} was
for a long time raised and lowered. In this manner all the moisture was
carried off from the mercury, and both the reservoirs were in proper
condition to be used. The reservoir R_{2} was then again raised to the
top, and the pump was kept working for a long time. When the highest
vacuum obtainable with the pump had been reached, the potash bulb was
usually wrapped with cotton which was sprinkled with ether so as to keep
the potash at a very low temperature, then the reservoir R_{2} was
lowered, and upon reservoir R_{1} being emptied the receiver was quickly
sealed up.

When a new bulb was put on, the mercury was always raised above stopcock
C_{1}, which was closed, so as to always keep the mercury and both the
reservoirs in fine condition, and the mercury was never withdrawn from
R_{1} except when the pump had reached the highest degree of exhaustion.
It is necessary to observe this rule if it is desired to use the
apparatus to advantage.

By means of this arrangement I was able to proceed very quickly, and
when the apparatus was in perfect order it was possible to reach the
phosphorescent stage in a small bulb in less than fifteen minutes, which
is certainly very quick work for a small laboratory arrangement
requiring all in all about 100 pounds of mercury. With ordinary small
bulbs the ratio of the capacity of the pump, receiver, and connections,
and that of reservoir R was about 1 to 20, and the degrees of exhaustion
reached were necessarily very high, though I am unable to make a precise
and reliable statement how far the exhaustion was carried.

What impresses the investigator most in the course of these experiences
is the behavior of gases when subjected to great rapidly alternating
electrostatic stresses. But he must remain in doubt as to whether the
effects observed are due wholly to the molecules, or atoms, of the gas
which chemical analysis discloses to us, or whether there enters into
play another medium of a gaseous nature, comprising atoms, or molecules,
immersed in a fluid pervading the space. Such a medium surely must
exist, and I am convinced that, for instance, even if air were absent,
the surface and neighborhood of a body in space would be heated by
rapidly alternating the potential of the body; but no such heating of
the surface or neighborhood could occur if all free atoms were removed
and only a homogeneous, incompressible, and elastic fluid--such as ether
is supposed to be--would remain, for then there would be no impacts, no
collisions. In such a case, as far as the body itself is concerned, only
frictional losses in the inside could occur.

It is a striking fact that the discharge through a gas is established
with ever-increasing freedom as the frequency of the impulses is
augmented. It behaves in this respect quite contrarily to a metallic
conductor. In the latter the impedance enters prominently into play as
the frequency is increased, but the gas acts much as a series of
condensers would; the facility with which the discharge passes through,
seems to depend on the rate of change of potential. If it acts so, then
in a vacuum tube even of great length, and no matter how strong the
current, self-induction could not assert itself to any appreciable
degree. We have, then, as far as we can now see, in the gas a conductor
which is capable of transmitting electric impulses of any frequency
which we may be able to produce. Could the frequency be brought high
enough, then a queer system of electric distribution, which would be
likely to interest gas companies, might be realized: metal pipes
filled with gas--the metal being the insulator, the gas the
conductor--supplying phosphorescent bulbs, or perhaps devices as yet
uninvented. It is certainly possible to take a hollow core of copper,
rarefy the gas in the same, and by passing impulses of sufficiently high
frequency through a circuit around it, bring the gas inside to a high
degree of incandescence; but as to the nature of the forces there would
be considerable uncertainty, for it would be doubtful whether with such
impulses the copper core would act as a static screen. Such paradoxes
and apparent impossibilities we encounter at every step in this line of
work, and therein lies, to a great extent, the charm of the study.

I have here a short and wide tube which is exhausted to a high degree
and covered with a substantial coating of bronze, the coating barely
allowing the light to shine through. A metallic cap, with a hook for
suspending the tube, is fastened around the middle portion of the
latter, the clasp being in contact with the bronze coating. I now want
to light the gas inside by suspending the tube on a wire connected to
the coil. Any one who would try the experiment for the first time, not
having any previous experience, would probably take care to be quite
alone when making the trial, for fear that he might become the joke of
his assistants. Still, the bulb lights in spite of the metal coating,
and the light can be distinctly perceived through the latter. A long
tube covered with aluminum bronze lights when held in one hand--the
other touching the terminal of the coil--quite powerfully. It might be
objected that the coatings are not sufficiently conducting; still, even
if they were highly resistant, they ought to screen the gas. They
certainly screen it perfectly in a condition of rest, but far from
perfectly when the charge is surging in the coating. But the loss of
energy which occurs within the tube, notwithstanding the screen, is
occasioned principally by the presence of the gas. Were we to take a
large hollow metallic sphere and fill it with a perfect, incompressible,
fluid dielectric, there would be no loss inside of the sphere, and
consequently the inside might be considered as perfectly screened,
though the potential be very rapidly alternating. Even were the sphere
filled with oil, the loss would be incomparably smaller than when the
fluid is replaced by a gas, for in the latter case the force produces
displacements; that means impact and collisions in the inside.

No matter what the pressure of the gas may be, it becomes an important
factor in the heating of a conductor when the electric density is great
and the frequency very high. That in the heating of conductors by
lightning discharges, air is an element of great importance, is almost
as certain as an experimental fact. I may illustrate the action of the
air by the following experiment: I take a short tube which is exhausted
to a moderate degree and has a platinum wire running through the middle
from one end to the other. I pass a steady or low frequency current
through the wire, and it is heated uniformly in all parts. The heating
here is due to conduction, or frictional losses, and the gas around the
wire has--as far as we can see--no function to perform. But now let me
pass sudden discharges, or high frequency currents, through the wire.
Again the wire is heated, this time principally on the ends and least in
the middle portion; and if the frequency of the impulses, or the rate of
change, is high enough, the wire might as well be cut in the middle as
not, for practically all heating is due to the rarefied gas. Here the
gas might only act as a conductor of no impedance diverting the current
from the wire as the impedance of the latter is enormously increased,
and merely heating the ends of the wire by reason of their resistance to
the passage of the discharge. But it is not at all necessary that the
gas in the tube should be conducting; it might be at an extremely low
pressure, still the ends of the wire would be heated--as, however, is
ascertained by experience--only the two ends would in such case not be
electrically connected through the gaseous medium. Now what with these
frequencies and potentials occurs in an exhausted tube, occurs in the
lightning discharges at ordinary pressure. We only need remember one of
the facts arrived at in the course of these investigations, namely, that
to impulses of very high frequency the gas at ordinary pressure behaves
much in the same manner as though it were at moderately low pressure. I
think that in lightning discharges frequently wires or conducting
objects are volatilized merely because air is present, and that, were
the conductor immersed in an insulating liquid, it would be safe, for
then the energy would have to spend itself somewhere else. From the
behavior of gases under sudden impulses of high potential, I am led to
conclude that there can be no surer way of diverting a lightning
discharge than by affording it a passage through a volume of gas, if
such a thing can be done in a practical manner.

There are two more features upon which I think it necessary to dwell in
connection with these experiments--the "radiant state" and the
"non-striking vacuum."

Any one who has studied Crookes' work must have received the impression
that the "radiant state" is a property of the gas inseparably connected
with an extremely high degree of exhaustion. But it should be remembered
that the phenomena observed in an exhausted vessel are limited to the
character and capacity of the apparatus which is made use of. I think
that in a bulb a molecule, or atom, does not precisely move in a
straight line because it meets no obstacle, but because the velocity
imparted to it is sufficient to propel it in a sensibly straight line.
The mean free path is one thing, but the velocity--the energy associated
with the moving body--is another, and under ordinary circumstances I
believe that it is a mere question of potential or speed. A disruptive
discharge coil, when the potential is pushed very far, excites
phosphorescence and projects shadows, at comparatively low degrees of
exhaustion. In a lightning discharge, matter moves in straight lines at
ordinary pressure when the mean free path is exceedingly small, and
frequently images of wires or other metallic objects have been produced
by the particles thrown off in straight lines.

I have prepared a bulb to illustrate by an experiment the correctness of
these assertions. In a globe L, Fig. 160, I have mounted upon a lamp
filament _f_ a piece of lime _l_. The lamp filament is connected with a
wire which leads into the bulb, and the general construction of the
latter is as indicated in Fig. 148, before described. The bulb being
suspended from a wire connected to the terminal of the coil, and the
latter being set to work, the lime piece _l_ and the projecting parts of
the filament _f_ are bombarded. The degree of exhaustion is just such
that with the potential the coil is capable of giving, phosphorescence
of the glass is produced, but disappears as soon as the vacuum is
impaired. The lime containing moisture, and moisture being given off as
soon as heating occurs, the phosphorescence lasts only for a few
moments. When the lime has been sufficiently heated, enough moisture has
been given off to impair materially the vacuum of the bulb. As the
bombardment goes on, one point of the lime piece is more heated than
other points, and the result is that finally practically all the
discharge passes through that point which is intensely heated, and a
white stream of lime particles (Fig. 160) then breaks forth from that
point. This stream is composed of "radiant" matter, yet the degree of
exhaustion is low. But the particles move in straight lines because the
velocity imparted to them is great, and this is due to three causes--to
the great electric density, the high temperature of the small point, and
the fact that the particles of the lime are easily torn and thrown
off--far more easily than those of carbon. With frequencies such as we
are able to obtain, the particles are bodily thrown off and projected to
a considerable distance; but with sufficiently high frequencies no such
thing would occur; in such case only a stress would spread or a
vibration would be propagated through the bulb. It would be out of the
question to reach any such frequency on the assumption that the atoms
move with the speed of light; but I believe that such a thing is
impossible; for this an enormous potential would be required. With
potentials which we are able to obtain, even with a disruptive discharge
coil, the speed must be quite insignificant.

[Illustration: FIG. 160.]

As to the "non-striking vacuum," the point to be noted is, that it can
occur only with low frequency impulses, and it is necessitated by the
impossibility of carrying off enough energy with such impulses in high
vacuum, since the few atoms which are around the terminal upon coming in
contact with the same, are repelled and kept at a distance for a
comparatively long period of time, and not enough work can be performed
to render the effect perceptible to the eye. If the difference of
potential between the terminals is raised, the dielectric breaks down.
But with very high frequency impulses there is no necessity for such
breaking down, since any amount of work can be performed by continually
agitating the atoms in the exhausted vessel, provided the frequency is
high enough. It is easy to reach--even with frequencies obtained from an
alternator as here used--a stage at which the discharge does not pass
between two electrodes in a narrow tube, each of these being connected
to one of the terminals of the coil, but it is difficult to reach a
point at which a luminous discharge would not occur around each
electrode.

[Illustration: FIG. 161.]

[Illustration: FIG. 162.]

A thought which naturally presents itself in connection with high
frequency currents, is to make use of their powerful electrodynamic
inductive action to produce light effects in a sealed glass globe. The
leading-in wire is one of the defects of the present incandescent lamp,
and if no other improvement were made, that imperfection at least should
be done away with. Following this thought, I have carried on
experiments in various directions, of which some were indicated in my
former paper. I may here mention one or two more lines of experiment
which have been followed up.

Many bulbs were constructed as shown in Fig. 161 and Fig. 162.

In Fig. 161, a wide tube, T, was sealed to a smaller W
shaped tube U, of phosphorescent glass. In the tube T, was placed a coil
C, of aluminum wire, the ends of which were provided with small spheres,
t and t_{1}, of aluminum, and reached into the U tube. The tube T
was slipped into a socket containing a primary coil, through which
usually the discharges of Leyden jars were directed, and the rarefied
gas in the small U tube was excited to strong luminosity by the
high-tension current induced in the coil C. When Leyden jar discharges
were used to induce currents in the coil C, it was found necessary to
pack the tube T tightly with insulating powder, as a discharge would
occur frequently between the turns of the coil, especially when the
primary was thick and the air gap, through which the jars discharged,
large, and no little trouble was experienced in this way.

In Fig. 162 is illustrated another form of the bulb constructed. In this
case a tube T is sealed to a globe L. The tube contains a coil C, the
ends of which pass through two small glass tubes t and t_{1}, which
are sealed to the tube T. Two refractory buttons m and m_{1}, are
mounted on lamp filaments which are fastened to the ends of the wires
passing through the glass tubes t and t_{1}. Generally in bulbs made
on this plan the globe L communicated with the tube T. For this purpose
the ends of the small tubes t and t_{1} were heated just a trifle in
the burner, merely to hold the wires, but not to interfere with the
communication. The tube T, with the small tubes, wires through the same,
and the refractory buttons m and m_{1}, were first prepared, and
then sealed to globe L, whereupon the coil C was slipped in and the
connections made to its ends. The tube was then packed with insulating
powder, jamming the latter as tight as possible up to very nearly the
end; then it was closed and only a small hole left through which the
remainder of the powder was introduced, and finally the end of the tube
was closed. Usually in bulbs constructed as shown in Fig. 162 an
aluminum tube _a_ was fastened to the upper end _s_ of each of the tubes
t and t_{1} in order to protect that end against the heat. The
buttons m and m_{1} could be brought to any degree of incandescence
by passing the discharges of Leyden jars around the coil C. In such
bulbs with two buttons a very curious effect is produced by the
formation of the shadows of each of the two buttons.

Another line of experiment, which has been assiduously followed, was to
induce by electro-dynamic induction a current or luminous discharge in
an exhausted tube or bulb. This matter has received such able treatment
at the hands of Prof. J. J. Thomson, that I could add but little to what
he has made known, even had I made it the special subject of this
lecture. Still, since experiments in this line have gradually led me to
the present views and results, a few words must be devoted here to this
subject.

It has occurred, no doubt, to many that as a vacuum tube is made longer,
the electromotive force per unit length of the tube, necessary to pass a
luminous discharge through the latter, becomes continually smaller;
therefore, if the exhausted tube be made long enough, even with low
frequencies a luminous discharge could be induced in such a tube closed
upon itself. Such a tube might be placed around a hall or on a ceiling,
and at once a simple appliance capable of giving considerable light
would be obtained. But this would be an appliance hard to manufacture
and extremely unmanageable. It would not do to make the tube up of small
lengths, because there would be with ordinary frequencies considerable
loss in the coatings, and besides, if coatings were used, it would be
better to supply the current directly to the tube by connecting the
coatings to a transformer. But even if all objections of such nature
were removed, with low frequencies the light conversion itself would be
inefficient, as I have before stated. In using extremely high
frequencies the length of the secondary--in other words, the size of the
vessel--can be reduced as much as desired, and the efficiency of the
light conversion is increased, provided that means are invented for
efficiently obtaining such high frequencies. Thus one is led, from
theoretical and practical considerations, to the use of high
frequencies, and this means high electromotive forces and small currents
in the primary. When one works with condenser charges--and they are the
only means up to the present known for reaching these extreme
frequencies--one gets to electromotive forces of several thousands of
volts per turn of the primary. We cannot multiply the electro-dynamic
inductive effect by taking more turns in the primary, for we arrive at
the conclusion that the best way is to work with one single turn--though
we must sometimes depart from this rule--and we must get along with
whatever inductive effect we can obtain with one turn. But before one
has long experimented with the extreme frequencies required to set up in
a small bulb an electromotive force of several thousands of volts, one
realizes the great importance of electrostatic effects, and these
effects grow relatively to the electro-dynamic in significance as the
frequency is increased.

Now, if anything is desirable in this case, it is to increase the
frequency, and this would make it still worse for the electrodynamic
effects. On the other hand, it is easy to exalt the electrostatic action
as far as one likes by taking more turns on the secondary, or combining
self-induction and capacity to raise the potential. It should also be
remembered that, in reducing the current to the smallest value and
increasing the potential, the electric impulses of high frequency can be
more easily transmitted through a conductor.

These and similar thoughts determined me to devote more attention to the
electrostatic phenomena, and to endeavor to produce potentials as high
as possible, and alternating as fast as they could be made to alternate.
I then found that I could excite vacuum tubes at considerable distance
from a conductor connected to a properly constructed coil, and that I
could, by converting the oscillatory current of a conductor to a higher
potential, establish electrostatic alternating fields which acted
through the whole extent of the room, lighting up a tube no matter where
it was held in space. I thought I recognized that I had made a step in
advance, and I have persevered in this line; but I wish to say that I
share with all lovers of science and progress the one and only
desire--to reach a result of utility to men in any direction to which
thought or experiment may lead me. I think that this departure is the
right one, for I cannot see, from the observation of the phenomena which
manifest themselves as the frequency is increased, what there would
remain to act between two circuits conveying, for instance, impulses of
several hundred millions per second, except electrostatic forces. Even
with such trifling frequencies the energy would be practically all
potential, and my conviction has grown strong that, to whatever kind of
motion light may be due, it is produced by tremendous electrostatic
stresses vibrating with extreme rapidity.

[Illustration: FIG. 163.]

[Illustration: FIG. 164.]

Of all these phenomena observed with currents, or electric impulses, of
high frequency, the most fascinating for an audience are certainly those
which are noted in an electrostatic field acting through considerable
distance; and the best an unskilled lecturer can do is to begin and
finish with the exhibition of these singular effects. I take a tube in
my hand and move it about, and it is lighted wherever I may hold it;
throughout space the invisible forces act. But I may take another tube
and it might not light, the vacuum being very high. I excite it by means
of a disruptive discharge coil, and now it will light in the
electrostatic field. I may put it away for a few weeks or months, still
it retains the faculty of being excited. What change have I produced in
the tube in the act of exciting it? If a motion imparted to atoms, it is
difficult to perceive how it can persist so long without being arrested
by frictional losses; and if a strain exerted in the dielectric, such as
a simple electrification would produce, it is easy to see how it may
persist indefinitely, but very difficult to understand why such a
condition should aid the excitation when we have to deal with potentials
which are rapidly alternating.

Since I have exhibited these phenomena for the first time, I have
obtained some other interesting effects. For instance, I have produced
the incandescence of a button, filament, or wire enclosed in a tube. To
get to this result it was necessary to economize the energy which is
obtained from the field, and direct most of it on the small body to be
rendered incandescent. At the beginning the task appeared difficult, but
the experiences gathered permitted me to reach the result easily. In
Fig. 163 and Fig. 164, two such tubes are illustrated, which are
prepared for the occasion. In Fig. 163 a short tube T_{1}, sealed to
another long tube T, is provided with a stem _s_, with a platinum wire
sealed in the latter. A very thin lamp filament _l_, is fastened to this
wire and connection to the outside is made through a thin copper wire
_w_. The tube is provided with outside and inside coatings, C and C_{1},
respectively, and is filled as far as the coatings reach with
conducting, and the space above with insulating, powder. These coatings
are merely used to enable me to perform two experiments with the
tube--namely, to produce the effect desired either by direct connection
of the body of the experimenter or of another body to the wire _w_, or
by acting inductively through the glass. The stem _s_ is provided with
an aluminum tube _a_, for purposes before explained, and only a small
part of the filament reaches out of this tube. By holding the tube T_{1}
anywhere in the electrostatic field, the filament is rendered
incandescent.

A more interesting piece of apparatus is illustrated in Fig. 164. The
construction is the same as before, only instead of the lamp filament a
small platinum wire _p_, sealed in a stem _s_, and bent above it in a
circle, is connected to the copper wire _w_, which is joined to an
inside coating C. A small stem s_{1} is provided with a needle, on the
point of which is arranged, to rotate very freely, a very light fan of
mica _v_. To prevent the fan from falling out, a thin stem of glass _g_,
is bent properly and fastened to the aluminum tube. When the glass tube
is held anywhere in the electrostatic field the platinum wire becomes
incandescent, and the mica vanes are rotated very fast.

Intense phosphorescence may be excited in a bulb by merely connecting it
to a plate within the field, and the plate need not be any larger than
an ordinary lamp shade. The phosphorescence excited with these currents
is incomparably more powerful than with ordinary apparatus. A small
phosphorescent bulb, when attached to a wire connected to a coil, emits
sufficient light to allow reading ordinary print at a distance of five
to six paces. It was of interest to see how some of the phosphorescent
bulbs of Professor Crookes would behave with these currents, and he has
had the kindness to lend me a few for the occasion. The effects produced
are magnificent, especially by the sulphide of calcium and sulphide of
zinc. With the disruptive discharge coil they glow intensely merely by
holding them in the hand and connecting the body to the terminal of the
coil.

To whatever results investigations of this kind may lead, the chief
interest lies, for the present, in the possibilities they offer for the
production of an efficient illuminating device. In no branch of electric
industry is an advance more desired than in the manufacture of light.
Every thinker, when considering the barbarous methods employed, the
deplorable losses incurred in our best systems of light production, must
have asked himself, What is likely to be the light of the future? Is it
to be an incandescent solid, as in the present lamp, or an incandescent
gas, or a phosphorescent body, or something like a burner, but
incomparably more efficient?

There is little chance to perfect a gas burner; not, perhaps, because
human ingenuity has been bent upon that problem for centuries without a
radical departure having been made--though the argument is not devoid of
force--but because in a burner the highest vibrations can never be
reached, except by passing through all the low ones. For how is a flame
to proceed unless by a fall of lifted weights? Such process cannot be
maintained without renewal, and renewal is repeated passing from low to
high vibrations. One way only seems to be open to improve a burner, and
that is by trying to reach higher degrees of incandescence. Higher
incandescence is equivalent to a quicker vibration: that means more
light from the same material, and that again, means more economy. In
this direction some improvements have been made, but the progress is
hampered by many limitations. Discarding, then, the burner, there
remains the three ways first mentioned, which are essentially
electrical.

Suppose the light of the immediate future to be a solid, rendered
incandescent by electricity. Would it not seem that it is better to
employ a small button than a frail filament? From many considerations it
certainly must be concluded that a button is capable of a higher
economy, assuming, of course, the difficulties connected with the
operation of such a lamp to be effectively overcome. But to light such
a lamp we require a high potential; and to get this economically, we
must use high frequencies.

Such considerations apply even more to the production of light by the
incandescence of a gas, or by phosphorescence. In all cases we require
high frequencies and high potentials. These thoughts occurred to me a
long time ago.

Incidentally we gain, by the use of high frequencies, many advantages,
such as higher economy in the light production, the possibility of
working with one lead, the possibility of doing away with the leading-in
wire, etc.

The question is, how far can we go with frequencies? Ordinary conductors
rapidly lose the facility of transmitting electric impulses when the
frequency is greatly increased. Assume the means for the production of
impulses of very great frequency brought to the utmost perfection, every
one will naturally ask how to transmit them when the necessity arises.
In transmitting such impulses through conductors we must remember that
we have to deal with _pressure_ and _flow_, in the ordinary
interpretation of these terms. Let the pressure increase to an enormous
value, and let the flow correspondingly diminish, then such
impulses--variations merely of pressure, as it were--can no doubt be
transmitted through a wire even if their frequency be many hundreds of
millions per second. It would, of course, be out of question to transmit
such impulses through a wire immersed in a gaseous medium, even if the
wire were provided with a thick and excellent insulation, for most of
the energy would be lost in molecular bombardment and consequent
heating. The end of the wire connected to the source would be heated,
and the remote end would receive but a trifling part of the energy
supplied. The prime necessity, then, if such electric impulses are to be
used, is to find means to reduce as much as possible the dissipation.

The first thought is, to employ the thinnest possible wire surrounded by
the thickest practicable insulation. The next thought is to employ
electrostatic screens. The insulation of the wire may be covered with a
thin conducting coating and the latter connected to the ground. But this
would not do, as then all the energy would pass through the conducting
coating to the ground and nothing would get to the end of the wire. If a
ground connection is made it can only be made through a conductor
offering an enormous impedance, or through a condenser of extremely
small capacity. This, however, does not do away with other difficulties.

If the wave length of the impulses is much smaller than the length of
the wire, then corresponding short waves will be set up in the
conducting coating, and it will be more or less the same as though the
coating were directly connected to earth. It is therefore necessary to
cut up the coating in sections much shorter than the wave length. Such
an arrangement does not still afford a perfect screen, but it is ten
thousand times better than none. I think it preferable to cut up the
conducting coating in small sections, even if the current waves be much
longer than the coating.

If a wire were provided with a perfect electrostatic screen, it would be
the same as though all objects were removed from it at infinite
distance. The capacity would then be reduced to the capacity of the wire
itself, which would be very small. It would then be possible to send
over the wire current vibrations of very high frequencies at enormous
distances, without affecting greatly the character of the vibrations. A
perfect screen is of course out of the question, but I believe that with
a screen such as I have just described telephony could be rendered
practicable across the Atlantic. According to my ideas, the gutta-percha
covered wire should be provided with a third conducting coating
subdivided in sections. On the top of this should be again placed a
layer of gutta-percha and other insulation, and on the top of the whole
the armor. But such cables will not be constructed, for ere long
intelligence--transmitted without wires--will throb through the earth
like a pulse through a living organism. The wonder is that, with the
present state of knowledge and the experiences gained, no attempt is
being made to disturb the electrostatic or magnetic condition of the
earth, and transmit, if nothing else, intelligence.

It has been my chief aim in presenting these results to point out
phenomena or features of novelty, and to advance ideas which I am
hopeful will serve as starting points of new departures. It has been my
chief desire this evening to entertain you with some novel experiments.
Your applause, so frequently and generously accorded, has told me that I
have succeeded.

In conclusion, let me thank you most heartily for your kindness and
attention, and assure you that the honor I have had in addressing such
a distinguished audience, the pleasure I have had in presenting these
results to a gathering of so many able men--and among them also some of
those in whose work for many years past I have found enlightenment and
constant pleasure--I shall never forget.




CHAPTER XXVIII.

ON LIGHT AND OTHER HIGH FREQUENCY PHENOMENA.[3]

  [3] A lecture delivered before the Franklin Institute, Philadelphia,
      February, 1893, and before the National Electric Light
      Association, St. Louis, March, 1893.


INTRODUCTORY.--SOME THOUGHTS ON THE EYE.

When we look at the world around us, on Nature, we are impressed with
its beauty and grandeur. Each thing we perceive, though it may be
vanishingly small, is in itself a world, that is, like the whole of the
universe, matter and force governed by law,--a world, the contemplation
of which fills us with feelings of wonder and irresistibly urges us to
ceaseless thought and inquiry. But in all this vast world, of all
objects our senses reveal to us, the most marvellous, the most appealing
to our imagination, appears no doubt a highly developed organism, a
thinking being. If there is anything fitted to make us admire Nature's
handiwork, it is certainly this inconceivable structure, which performs
its innumerable motions of obedience to external influence. To
understand its workings, to get a deeper insight into this Nature's
masterpiece, has ever been for thinkers a fascinating aim, and after
many centuries of arduous research men have arrived at a fair
understanding of the functions of its organs and senses. Again, in all
the perfect harmony of its parts, of the parts which constitute the
material or tangible of our being, of all its organs and senses, the eye
is the most wonderful. It is the most precious, the most indispensable
of our perceptive or directive organs, it is the great gateway through
which all knowledge enters the mind. Of all our organs, it is the one,
which is in the most intimate relation with that which we call
intellect. So intimate is this relation, that it is often said, the very
soul shows itself in the eye.

It can be taken as a fact, which the theory of the action of the eye
implies, that for each external impression, that is, for each image
produced upon the retina, the ends of the visual nerves, concerned in
the conveyance of the impression to the mind, must be under a peculiar
stress or in a vibratory state. It now does not seem improbable that,
when by the power of thought an image is evoked, a distinct reflex
action, no matter how weak, is exerted upon certain ends of the visual
nerves, and therefore upon the retina. Will it ever be within human
power to analyze the condition of the retina when disturbed by thought
or reflex action, by the help of some optical or other means of such
sensitiveness, that a clear idea of its state might be gained at any
time? If this were possible, then the problem of reading one's thoughts
with precision, like the characters of an open book, might be much
easier to solve than many problems belonging to the domain of positive
physical science, in the solution of which many, if not the majority, of
scientific men implicitly believe. Helmholtz, has shown that the fundi
of the eye are themselves, luminous, and he was able to _see_, in total
darkness, the movement of his arm by the light of his own eyes. This is
one of the most remarkable experiments recorded in the history of
science, and probably only a few men could satisfactorily repeat it, for
it is very likely, that the luminosity of the eyes is associated with
uncommon activity of the brain and great imaginative power. It is
fluorescence of brain action, as it were.

Another fact having a bearing on this subject which has probably been
noted by many, since it is stated in popular expressions, but which I
cannot recollect to have found chronicled as a positive result of
observation is, that at times, when a sudden idea or image presents
itself to the intellect, there is a distinct and sometimes painful
sensation of luminosity produced in the eye, observable even in broad
daylight.

The saying then, that the soul shows itself in the eye, is deeply
founded, and we feel that it expresses a great truth. It has a profound
meaning even for one who, like a poet or artist, only following his
inborn instinct or love for Nature, finds delight in aimless thoughts
and in the mere contemplation of natural phenomena, but a still more
profound meaning for one who, in the spirit of positive scientific
investigation, seeks to ascertain the causes of the effects. It is
principally the natural philosopher, the physicist, for whom the eye is
the subject of the most intense admiration.

Two facts about the eye must forcibly impress the mind of the physicist,
notwithstanding he may think or say that it is an imperfect optical
instrument, forgetting, that the very conception of that which is
perfect or seems so to him, has been gained through this same
instrument. First, the eye is, as far as our positive knowledge goes,
the only organ which is _directly_ affected by that subtile medium,
which as science teaches us, must fill all space; secondly, it is the
most sensitive of our organs, incomparably more sensitive to external
impressions than any other.

The organ of hearing implies the impact of ponderable bodies, the organ
of smell the transference of detached material particles, and the organs
of taste, and of touch or force, the direct contact, or at least some
interference of ponderable matter, and this is true even in those
instances of animal organisms, in which some of these organs are
developed to a degree of truly marvelous perfection. This being so, it
seems wonderful that the organ of sight solely should be capable of
being stirred by that, which all our other organs are powerless to
detect, yet which plays an essential part in all natural phenomena,
which transmits all energy and sustains all motion and, that most
intricate of all, life, but which has properties such that even a
scientifically trained mind cannot help drawing a distinction between it
and all that is called matter. Considering merely this, and the fact
that the eye, by its marvelous power, widens our otherwise very narrow
range of perception far beyond the limits of the small world which is
our own, to embrace myriads of other worlds, suns and stars in the
infinite depths of the universe, would make it justifiable to assert,
that it is an organ of a higher order. Its performances are beyond
comprehension. Nature as far as we know never produced anything more
wonderful. We can get barely a faint idea of its prodigious power by
analyzing what it does and by comparing. When ether waves impinge upon
the human body, they produce the sensations of warmth or cold, pleasure
or pain, or perhaps other sensations of which we are not aware, and any
degree or intensity of these sensations, which degrees are infinite in
number, hence an infinite number of distinct sensations. But our sense
of touch, or our sense of force, cannot reveal to us these differences
in degree or intensity, unless they are very great. Now we can readily
conceive how an organism, such as the human, in the eternal process of
evolution, or more philosophically speaking, adaptation to Nature, being
constrained to the use of only the sense of touch or force, for
instance, might develop this sense to such a degree of sensitiveness or
perfection, that it would be capable of distinguishing the minutest
differences in the temperature of a body even at some distance, to a
hundredth, or thousandth, or millionth part of a degree. Yet, even this
apparently impossible performance would not begin to compare with that
of the eye, which is capable of distinguishing and conveying to the mind
in a single instant innumerable peculiarities of the body, be it in
form, or color, or other respects. This power of the eye rests upon two
things, namely, the rectilinear propagation of the disturbance by which
it is effected, and upon its sensitiveness. To say that the eye is
sensitive is not saying anything. Compared with it, all other organs are
monstrously crude. The organ of smell which guides a dog on the trail of
a deer, the organ of touch or force which guides an insect in its
wanderings, the organ of hearing, which is affected by the slightest
disturbances of the air, are sensitive organs, to be sure, but what are
they compared with the human eye! No doubt it responds to the faintest
echoes or reverberations of the medium; no doubt, it brings us tidings
from other worlds, infinitely remote, but in a language we cannot as yet
always understand. And why not? Because we live in a medium filled with
air and other gases, vapors and a dense mass of solid particles flying
about. These play an important part in many phenomena; they fritter away
the energy of the vibrations before they can reach the eye; they too,
are the carriers of germs of destruction, they get into our lungs and
other organs, clog up the channels and imperceptibly, yet inevitably,
arrest the stream of life. Could we but do away with all ponderable
matter in the line of sight of the telescope, it would reveal to us
undreamt of marvels. Even the unaided eye, I think, would be capable of
distinguishing in the pure medium, small objects at distances measured
probably by hundreds or perhaps thousands of miles.

But there is something else about the eye which impresses us still more
than these wonderful features which we observed, viewing it from the
standpoint of a physicist, merely as an optical instrument,--something
which appeals to us more than its marvelous faculty of being directly
affected by the vibrations of the medium, without interference of gross
matter, and more than its inconceivable sensitiveness and discerning
power. It is its significance in the processes of life. No matter what
one's views on nature and life may be, he must stand amazed when, for
the first time in his thoughts, he realizes the importance of the eye in
the physical processes and mental performances of the human organism.
And how could it be otherwise, when he realizes, that the eye is the
means through which the human race has acquired the entire knowledge it
possesses, that it controls all our motions, more still, all our
actions.

There is no way of acquiring knowledge except through the eye. What is
the foundation of all philosophical systems of ancient and modern times,
in fact, of all the philosophy of man? _I am, I think; I think,
therefore I am._ But how could I think and how would I know that I
exist, if I had not the eye? For knowledge involves consciousness;
consciousness involves ideas, conceptions; conceptions involve pictures
or images, and images the sense of vision, and therefore the organ of
sight. But how about blind men, will be asked? Yes, a blind man may
depict in magnificent poems, forms and scenes from real life, from a
world he physically does not see. A blind man may touch the keys of an
instrument with unerring precision, may model the fastest boat, may
discover and invent, calculate and construct, may do still greater
wonders--but all the blind men who have done such things have descended
from those who had seeing eyes. Nature may reach the same result in many
ways. Like a wave in the physical world, in the infinite ocean of the
medium which pervades all, so in the world of organisms, in life, an
impulse started proceeds onward, at times, may be, with the speed of
light, at times, again, so slowly that for ages and ages it seems to
stay, passing through processes of a complexity inconceivable to men,
but in all its forms, in all its stages, its energy ever and ever
integrally present. A single ray of light from a distant star falling
upon the eye of a tyrant in bygone times, may have altered the course of
his life, may have changed the destiny of nations, may have transformed
the surface of the globe, so intricate, so inconceivably complex are the
processes in Nature. In no way can we get such an overwhelming idea of
the grandeur of Nature, as when we consider, that in accordance with the
law of the conservation of energy, throughout the infinite, the forces
are in a perfect balance, and hence the energy of a single thought may
determine the motion of a Universe. It is not necessary that every
individual, not even that every generation or many generations, should
have the physical instrument of sight, in order to be able to form
images and to think, that is, form ideas or conceptions; but sometime or
other, during the process of evolution, the eye certainly must have
existed, else thought, as we understand it, would be impossible; else
conceptions, like spirit, intellect, mind, call it as you may, could not
exist. It is conceivable, that in some other world, in some other
beings, the eye is replaced by a different organ, equally or more
perfect, but these beings cannot be men.

Now what prompts us all to voluntary motions and actions of any kind?
Again the eye. If I am conscious of the motion, I must have an idea or
conception, that is, an image, therefore the eye. If I am not precisely
conscious of the motion, it is, because the images are vague or
indistinct, being blurred by the superimposition of many. But when I
perform the motion, does the impulse which prompts me to the action come
from within or from without? The greatest physicists have not disdained
to endeavor to answer this and similar questions and have at times
abandoned themselves to the delights of pure and unrestrained thought.
Such questions are generally considered not to belong to the realm of
positive physical science, but will before long be annexed to its
domain. Helmholtz has probably thought more on life than any modern
scientist. Lord Kelvin expressed his belief that life's process is
electrical and that there is a force inherent to the organism and
determining its motions. Just as much as I am convinced of any physical
truth I am convinced that the motive impulse must come from the outside.
For, consider the lowest organism we know--and there are probably many
lower ones--an aggregation of a few cells only. If it is capable of
voluntary motion it can perform an infinite number of motions, all
definite and precise. But now a mechanism consisting of a finite number
of parts and few at that, cannot perform an infinite number of definite
motions, hence the impulses which govern its movements must come from
the environment. So, the atom, the ulterior element of the Universe's
structure, is tossed about in space, eternally, a play to external
influences, like a boat in a troubled sea. Were it to stop its motion
_it would die_. Matter at rest, if such a thing could exist, would be
matter dead. Death of matter! Never has a sentence of deeper
philosophical meaning been uttered. This is the way in which Prof.
Dewar forcibly expresses it in the description of his admirable
experiments, in which liquid oxygen is handled as one handles water, and
air at ordinary pressure is made to condense and even to solidify by the
intense cold. Experiments, which serve to illustrate, in his language,
the last feeble manifestations of life, the last quiverings of matter
about to die. But human eyes shall not witness such death. There is no
death of matter, for throughout the infinite universe, all has to move,
to vibrate, that is, to live.

I have made the preceding statements at the peril of treading upon
metaphysical ground, in my desire to introduce the subject of this
lecture in a manner not altogether uninteresting, I may hope, to an
audience such as I have the honor to address. But now, then, returning
to the subject, this divine organ of sight, this indispensable
instrument for thought and all intellectual enjoyment, which lays open
to us the marvels of this universe, through which we have acquired what
knowledge we possess, and which prompts us to, and controls, all our
physical and mental activity. By what is it affected? By light! What is
light?

We have witnessed the great strides which have been made in all
departments of science in recent years. So great have been the advances
that we cannot refrain from asking ourselves, Is this all true, or is it
but a dream? Centuries ago men have lived, have thought, discovered,
invented, and have believed that they were soaring, while they were
merely proceeding at a snail's pace. So we too may be mistaken. But
taking the truth of the observed events as one of the implied facts of
science, we must rejoice in the immense progress already made and still
more in the anticipation of what must come, judging from the
possibilities opened up by modern research. There is, however, an
advance which we have been witnessing, which must be particularly
gratifying to every lover of progress. It is not a discovery, or an
invention, or an achievement in any particular direction. It is an
advance in all directions of scientific thought and experiment. I mean
the generalization of the natural forces and phenomena, the looming up
of a certain broad idea on the scientific horizon. It is this idea which
has, however, long ago taken possession of the most advanced minds, to
which I desire to call your attention, and which I intend to illustrate
in a general way, in these experiments, as the first step in answering
the question "What is light?" and to realize the modern meaning of this
word.

It is beyond the scope of my lecture to dwell upon the subject of light
in general, my object being merely to bring presently to your notice a
certain class of light effects and a number of phenomena observed in
pursuing the study of these effects. But to be consistent in my remarks
it is necessary to state that, according to that idea, now accepted by
the majority of scientific men as a positive result of theoretical and
experimental investigation, the various forms or manifestations of
energy which were generally designated as "electric" or more precisely
"electromagnetic" are energy manifestations of the same nature as those
of radiant heat and light. Therefore the phenomena of light and heat and
others besides these, may be called electrical phenomena. Thus
electrical science has become the mother science of all and its study
has become all important. The day when we shall know exactly what
"electricity" is, will chronicle an event probably greater, more
important than any other recorded in the history of the human race. The
time will come when the comfort, the very existence, perhaps, of man
will depend upon that wonderful agent. For our existence and comfort we
require heat, light and mechanical power. How do we now get all these?
We get them from fuel, we get them by consuming material. What will man
do when the forests disappear, when the coal fields are exhausted? Only
one thing, according to our present knowledge will remain; that is, to
transmit power at great distances. Men will go to the waterfalls, to the
tides, which are the stores of an infinitesimal part of Nature's
immeasurable energy. There will they harness the energy and transmit the
same to their settlements, to warm their homes by, to give them light,
and to keep their obedient slaves, the machines, toiling. But how will
they transmit this energy if not by electricity? Judge then, if the
comfort, nay, the very existence, of man will not depend on electricity.
I am aware that this view is not that of a practical engineer, but
neither is it that of an illusionist, for it is certain, that power
transmission, which at present is merely a stimulus to enterprise, will
some day be a dire necessity.

It is more important for the student, who takes up the study of light
phenomena, to make himself thoroughly acquainted with certain modern
views, than to peruse entire books on the subject of light itself, as
disconnected from these views. Were I therefore to make these
demonstrations before students seeking information--and for the sake of
the few of those who may be present, give me leave to so assume--it
would be my principal endeavor to impress these views upon their minds
in this series of experiments.

It might be sufficient for this purpose to perform a simple and
well-known experiment. I might take a familiar appliance, a Leyden jar,
charge it from a frictional machine, and then discharge it. In
explaining to you its permanent state when charged, and its transitory
condition when discharging, calling your attention to the forces which
enter into play and to the various phenomena they produce, and pointing
out the relation of the forces and phenomena, I might fully succeed in
illustrating that modern idea. No doubt, to the thinker, this simple
experiment would appeal as much as the most magnificent display. But
this is to be an experimental demonstration, and one which should
possess, besides instructive, also entertaining features and as such, a
simple experiment, such as the one cited, would not go very far towards
the attainment of the lecturer's aim. I must therefore choose another
way of illustrating, more spectacular certainly, but perhaps also more
instructive. Instead of the frictional machine and Leyden jar, I shall
avail myself in these experiments, of an induction coil of peculiar
properties, which was described in detail by me in a lecture before the
London Institution of Electrical Engineers, in Feb., 1892. This
induction coil is capable of yielding currents of enormous potential
differences, alternating with extreme rapidity. With this apparatus I
shall endeavor to show you three distinct classes of effects, or
phenomena, and it is my desire that each experiment, while serving for
the purposes of illustration, should at the same time teach us some
novel truth, or show us some novel aspect of this fascinating science.
But before doing this, it seems proper and useful to dwell upon the
apparatus employed, and method of obtaining the high potentials and
high-frequency currents which are made use of in these experiments.


[Illustration: FIG. 165.]

ON THE APPARATUS AND METHOD OF CONVERSION.

These high-frequency currents are obtained in a peculiar manner. The
method employed was advanced by me about two years ago in an
experimental lecture before the American Institute of Electrical
Engineers. A number of ways, as practiced in the laboratory, of
obtaining these currents either from continuous or low frequency
alternating currents, is diagramatically indicated in Fig. 165, which
will be later described in detail. The general plan is to charge
condensers, from a direct or alternate-current source, preferably of
high-tension, and to discharge them disruptively while observing
well-known conditions necessary to maintain the oscillations of the
current. In view of the general interest taken in high-frequency
currents and effects producible by them, it seems to me advisable to
dwell at some length upon this method of conversion. In order to give
you a clear idea of the action, I will suppose that a continuous-current
generator is employed, which is often very convenient. It is desirable
that the generator should possess such high tension as to be able to
break through a small air space. If this is not the case, then auxiliary
means have to be resorted to, some of which will be indicated
subsequently. When the condensers are charged to a certain potential,
the air, or insulating space, gives way and a disruptive discharge
occurs. There is then a sudden rush of current and generally a large
portion of accumulated electrical energy spends itself. The condensers
are thereupon quickly charged and the same process is repeated in more
or less rapid succession. To produce such sudden rushes of current it is
necessary to observe certain conditions. If the rate at which the
condensers are discharged is the same as that at which they are charged,
then, clearly, in the assumed case the condensers do not come into play.
If the rate of discharge be smaller than the rate of charging, then,
again, the condensers cannot play an important part. But if, on the
contrary, the rate of discharging is greater than that of charging, then
a succession of rushes of current is obtained. It is evident that, if
the rate at which the energy is dissipated by the discharge is very much
greater than the rate of supply to the condensers, the sudden rushes
will be comparatively few, with long-time intervals between. This always
occurs when a condenser of considerable capacity is charged by means of
a comparatively small machine. If the rates of supply and dissipation
are not widely different, then the rushes of current will be in quicker
succession, and this the more, the more nearly equal both the rates are,
until limitations incident to each case and depending upon a number of
causes are reached. Thus we are able to obtain from a continuous-current
generator as rapid a succession of discharges as we like. Of course, the
higher the tension of the generator, the smaller need be the capacity of
the condensers, and for this reason, principally, it is of advantage to
employ a generator of very high tension. Besides, such a generator
permits the attaining of greater rates of vibration.

The rushes of current may be of the same direction under the conditions
before assumed, but most generally there is an oscillation superimposed
upon the fundamental vibration of the current. When the conditions are
so determined that there are no oscillations, the current impulses are
unidirectional and thus a means is provided of transforming a continuous
current of high tension, into a direct current of lower tension, which I
think may find employment in the arts.

This method of conversion is exceedingly interesting and I was much
impressed by its beauty when I first conceived it. It is ideal in
certain respects. It involves the employment of no mechanical devices of
any kind, and it allows of obtaining currents of any desired frequency
from an ordinary circuit, direct or alternating. The frequency of the
fundamental discharges depending on the relative rates of supply and
dissipation can be readily varied within wide limits, by simple
adjustments of these quantities, and the frequency of the superimposed
vibration by the determination of the capacity, self-induction and
resistance of the circuit. The potential of the currents, again, may be
raised as high as any insulation is capable of withstanding safely by
combining capacity and self-induction or by induction in a secondary,
which need have but comparatively few turns.

As the conditions are often such that the intermittence or oscillation
does not readily establish itself, especially when a direct current
source is employed, it is of advantage to associate an interrupter with
the arc, as I have, some time ago, indicated the use of an air-blast or
magnet, or other such device readily at hand. The magnet is employed
with special advantage in the conversion of direct currents, as it is
then very effective. If the primary source is an alternate current
generator, it is desirable, as I have stated on another occasion, that
the frequency should be low, and that the current forming the arc be
large, in order to render the magnet more effective.

A form of such discharger with a magnet which has been found convenient,
and adopted after some trials, in the conversion of direct currents
particularly, is illustrated in Fig. 166. N S are the pole pieces of a
very strong magnet which is excited by a coil C. The pole pieces are
slotted for adjustment and can be fastened in any position by screws s
s_{1}. The discharge rods d d_{1}, thinned down on the ends in order
to allow a closer approach of the magnetic pole pieces, pass through the
columns of brass b b_{1} and are fastened in position by screws s_{2}
s_{2}. Springs r r_{1} and collars c c_{1} are slipped on the
rods, the latter serving to set the points of the rods at a certain
suitable distance by means of screws s_{3} s_{3}, and the former to
draw the points apart. When it is desired to start the arc, one of the
large rubber handles h h_{1} is tapped quickly with the hand, whereby
the points of the rods are brought in contact but are instantly
separated by the springs r r_{1}. Such an arrangement has been found
to be often necessary, namely in cases when the E. M. F. was not large
enough to cause the discharge to break through the gap, and also when it
was desirable to avoid short circuiting of the generator by the metallic
contact of the rods. The rapidity of the interruptions of the current
with a magnet depends on the intensity of the magnetic field and on the
potential difference at the end of the arc. The interruptions are
generally in such quick succession as to produce a musical sound. Years
ago it was observed that when a powerful induction coil is discharged
between the poles of a strong magnet, the discharge produces a loud
noise, not unlike a small pistol shot. It was vaguely stated that the
spark was intensified by the presence of the magnetic field. It is now
clear that the discharge current, flowing for some time, was interrupted
a great number of times by the magnet, thus producing the sound. The
phenomenon is especially marked when the field circuit of a large magnet
or dynamo is broken in a powerful magnetic field.

[Illustration: FIG. 166.]

When the current through the gap is comparatively large, it is of
advantage to slip on the points of the discharge rods pieces of very
hard carbon and let the arc play between the carbon pieces. This
preserves the rods, and besides has the advantage of keeping the air
space hotter, as the heat is not conducted away as quickly through the
carbons, and the result is that a smaller E. M. F. in the arc gap is
required to maintain a succession of discharges.

[Illustration: FIG. 167.]

Another form of discharger, which may be employed with advantage in
some cases, is illustrated in Fig. 167. In this form the discharge rods
d d_{1} pass through perforations in a wooden box B, which is thickly
coated with mica on the inside, as indicated by the heavy lines. The
perforations are provided with mica tubes m m_{1} of some thickness,
which are preferably not in contact with the rods d d_{1}. The box has
a cover C which is a little larger and descends on the outside of the
box. The spark gap is warmed by a small lamp _l_ contained in the box. A
plate _p_ above the lamp allows the draught to pass only through the
chimney _e_ of the lamp, the air entering through holes _o o_ in or near
the bottom of the box and following the path indicated by the arrows.
When the discharger is in operation, the door of the box is closed so
that the light of the arc is not visible outside. It is desirable to
exclude the light as perfectly as possible, as it interferes with some
experiments. This form of discharger is simple and very effective when
properly manipulated. The air being warmed to a certain temperature, has
its insulating power impaired; it becomes dielectrically weak, as it
were, and the consequence is that the arc can be established at much
greater distance. The arc should, of course, be sufficiently insulating
to allow the discharge to pass through the gap _disruptively_. The arc
formed under such conditions, when long, may be made extremely
sensitive, and the weak draught through the lamp chimney _c_ is quite
sufficient to produce rapid interruptions. The adjustment is made by
regulating the temperature and velocity of the draught. Instead of using
the lamp, it answers the purpose to provide for a draught of warm air in
other ways. A very simple way which has been practiced is to enclose the
arc in a long vertical tube, with plates on the top and bottom for
regulating the temperature and velocity of the air current. Some
provision had to be made for deadening the sound.

The air may be rendered dielectrically weak also by rarefaction.
Dischargers of this kind have likewise been used by me in connection
with a magnet. A large tube is for this purpose provided with heavy
electrodes of carbon or metal, between which the discharge is made to
pass, the tube being placed in a powerful magnetic field. The exhaustion
of the tube is carried to a point at which the discharge breaks through
easily, but the pressure should be more than 75 millimetres, at which
the ordinary thread discharge occurs. In another form of discharger,
combining the features before mentioned, the discharge was made to pass
between two adjustable magnetic pole pieces, the space between them
being kept at an elevated temperature.

It should be remarked here that when such, or interrupting devices of
any kind, are used and the currents are passed through the primary of a
disruptive discharge coil, it is not, as a rule, of advantage to produce
a number of interruptions of the current per second greater than the
natural frequency of vibration of the dynamo supply circuit, which is
ordinarily small. It should also be pointed out here, that while the
devices mentioned in connection with the disruptive discharge are
advantageous under certain conditions, they may be sometimes a source of
trouble, as they produce intermittences and other irregularities in the
vibration which it would be very desirable to overcome.

There is, I regret to say, in this beautiful method of conversion a
defect, which fortunately is not vital, and which I have been gradually
overcoming. I will best call attention to this defect and indicate a
fruitful line of work, by comparing the electrical process with its
mechanical analogue. The process may be illustrated in this manner.
Imagine a tank with a wide opening at the bottom, which is kept closed
by spring pressure, but so that it snaps off _suddenly_ when the liquid
in the tank has reached a certain height. Let the fluid be supplied to
the tank by means of a pipe feeding at a certain rate. When the critical
height of the liquid is reached, the spring gives way and the bottom of
the tank drops out. Instantly the liquid falls through the wide opening,
and the spring, reasserting itself, closes the bottom again. The tank is
now filled, and after a certain time interval the same process is
repeated. It is clear, that if the pipe feeds the fluid quicker than the
bottom outlet is capable of letting it pass through, the bottom will
remain off and the tank will still overflow. If the rates of supply are
exactly equal, then the bottom lid will remain partially open and no
vibration of the same and of the liquid column will generally occur,
though it might, if started by some means. But if the inlet pipe does
not feed the fluid fast enough for the outlet, then there will be always
vibration. Again, in such case, each time the bottom flaps up or down,
the spring and the liquid column, if the pliability of the spring and
the inertia of the moving parts are properly chosen, will perform
independent vibrations. In this analogue the fluid may be likened to
electricity or electrical energy, the tank to the condenser, the spring
to the dielectric, and the pipe to the conductor through which
electricity is supplied to the condenser. To make this analogy quite
complete it is necessary to make the assumption, that the bottom, each
time it gives way, is knocked violently against a non-elastic stop, this
impact involving some loss of energy; and that, besides, some
dissipation of energy results due to frictional losses. In the preceding
analogue the liquid is supposed to be under a steady pressure. If the
presence of the fluid be assumed to vary rhythmically, this may be taken
as corresponding to the case of an alternating current. The process is
then not quite as simple to consider, but the action is the same in
principle.

It is desirable, in order to maintain the vibration economically, to
reduce the impact and frictional losses as much as possible. As regards
the latter, which in the electrical analogue correspond to the losses
due to the resistance of the circuits, it is impossible to obviate them
entirely, but they can be reduced to a minimum by a proper selection of
the dimensions of the circuits and by the employment of thin conductors
in the form of strands. But the loss of energy caused by the first
breaking through of the dielectric--which in the above example
corresponds to the violent knock of the bottom against the inelastic
stop--would be more important to overcome. At the moment of the breaking
through, the air space has a very high resistance, which is probably
reduced to a very small value when the current has reached some
strength, and the space is brought to a high temperature. It would
materially diminish the loss of energy if the space were always kept at
an extremely high temperature, but then there would be no disruptive
break. By warming the space moderately by means of a lamp or otherwise,
the economy as far as the arc is concerned is sensibly increased. But
the magnet or other interrupting device does not diminish the loss in
the arc. Likewise, a jet of air only facilitates the carrying off of the
energy. Air, or a gas in general, behaves curiously in this respect.
When two bodies charged to a very high potential, discharge disruptively
through an air space, any amount of energy may be carried off by the
air. This energy is evidently dissipated by bodily carriers, in impact
and collisional losses of the molecules. The exchange of the molecules
in the space occurs with inconceivable rapidity. A powerful discharge
taking place between two electrodes, they may remain entirely cool, and
yet the loss in the air may represent any amount of energy. It is
perfectly practicable, with very great potential differences in the gap,
to dissipate several horse-power in the arc of the discharge without
even noticing a small increase in the temperature of the electrodes. All
the frictional losses occur then practically in the air. If the exchange
of the air molecules is prevented, as by enclosing the air hermetically,
the gas inside of the vessel is brought quickly to a high temperature,
even with a very small discharge. It is difficult to estimate how much
of the energy is lost in sound waves, audible or not, in a powerful
discharge. When the currents through the gap are large, the electrodes
may become rapidly heated, but this is not a reliable measure of the
energy wasted in the arc, as the loss through the gap itself may be
comparatively small. The air or a gas in general is, at ordinary
pressure at least, clearly not the best medium through which a
disruptive discharge should occur. Air or other gas under great pressure
is of course a much more suitable medium for the discharge gap. I have
carried on long-continued experiments in this direction, unfortunately
less practicable on account of the difficulties and expense in getting
air under great pressure. But even if the medium in the discharge space
is solid or liquid, still the same losses take place, though they are
generally smaller, for just as soon as the arc is established, the solid
or liquid is volatilized. Indeed, there is no body known which would not
be disintegrated by the arc, and it is an open question among scientific
men, whether an arc discharge could occur at all in the air itself
without the particles of the electrodes being torn off. When the current
through the gap is very small and the arc very long, I believe that a
relatively considerable amount of heat is taken up in the disintegration
of the electrodes, which partially on this account may remain quite
cold.

The ideal medium for a discharge gap should only _crack_, and the ideal
electrode should be of some material which cannot be disintegrated. With
small currents through the gap it is best to employ aluminum, but not
when the currents are large. The disruptive break in the air, or more or
less in any ordinary medium, is not of the nature of a crack, but it is
rather comparable to the piercing of innumerable bullets through a mass
offering great frictional resistances to the motion of the bullets, this
involving considerable loss of energy. A medium which would merely crack
when strained electrostatically--and this possibly might be the case
with a perfect vacuum, that is, pure ether--would involve a very small
loss in the gap, so small as to be entirely negligible, at least
theoretically, because a crack may be produced by an infinitely small
displacement. In exhausting an oblong bulb provided with two aluminum
terminals, with the greatest care, I have succeeded in producing such a
vacuum that the secondary discharge of a disruptive discharge coil would
break disruptively through the bulb in the form of fine spark streams.
The curious point was that the discharge would completely ignore the
terminals and start far behind the two aluminum plates which served as
electrodes. This extraordinary high vacuum could only be maintained for
a very short while. To return to the ideal medium, think, for the sake
of illustration, of a piece of glass or similar body clamped in a vice,
and the latter tightened more and more. At a certain point a minute
increase of the pressure will cause the glass to crack. The loss of
energy involved in splitting the glass may be practically nothing, for
though the force is great, the displacement need be but extremely small.
Now imagine that the glass would possess the property of closing again
perfectly the crack upon a minute diminution of the pressure. This is
the way the dielectric in the discharge space should behave. But
inasmuch as there would be always some loss in the gap, the medium,
which should be continuous, should exchange through the gap at a rapid
rate. In the preceding example, the glass being perfectly closed, it
would mean that the dielectric in the discharge space possesses a great
insulating power; the glass being cracked, it would signify that the
medium in the space is a good conductor. The dielectric should vary
enormously in resistance by minute variations of the E. M. F. across the
discharge space. This condition is attained, but in an extremely
imperfect manner, by warming the air space to a certain critical
temperature, dependent on the E. M. F. across the gap, or by otherwise
impairing the insulating power of the air. But as a matter of fact the
air does never break down _disruptively_, if this term be rigorously
interpreted, for before the sudden rush of the current occurs, there is
always a weak current preceding it, which rises first gradually and then
with comparative suddenness. That is the reason why the rate of change
is very much greater when glass, for instance, is broken through, than
when the break takes place through an air space of equivalent dielectric
strength. As a medium for the discharge space, a solid, or even a
liquid, would be preferable therefor. It is somewhat difficult to
conceive of a solid body which would possess the property of closing
instantly after it has been cracked. But a liquid, especially under
great pressure, behaves practically like a solid, while it possesses the
property of closing the crack. Hence it was thought that a liquid
insulator might be more suitable as a dielectric than air. Following out
this idea, a number of different forms of dischargers in which a variety
of such insulators, sometimes under great pressure, were employed, have
been experimented upon. It is thought sufficient to dwell in a few words
upon one of the forms experimented upon. One of these dischargers is
illustrated in Figs. 168_a_ and 168_b_.

[Illustration: FIG. 168a.]

[Illustration: FIG. 168b.]

A hollow metal pulley P (Fig. 168_a_), was fastened upon an arbor _a_,
which by suitable means was rotated at a considerable speed. On the
inside of the pulley, but disconnected from the same, was supported a
thin disc _h_ (which is shown thick for the sake of clearness), of hard
rubber in which there were embedded two metal segments _s s_ with
metallic extensions _e e_ into which were screwed conducting terminals
_t t_ covered with thick tubes of hard rubber _t t_. The rubber disc _h_
with its metallic segments _s s_, was finished in a lathe, and its
entire surface highly polished so as to offer the smallest possible
frictional resistance to the motion through a fluid. In the hollow of
the pulley an insulating liquid such as a thin oil was poured so as to
reach very nearly to the opening left in the flange _f_, which was
screwed tightly on the front side of the pulley. The terminals _t t_,
were connected to the opposite coatings of a battery of condensers so
that the discharge occurred through the liquid. When the pulley was
rotated, the liquid was forced against the rim of the pulley and
considerable fluid pressure resulted. In this simple way the discharge
gap was filled with a medium which behaved practically like a solid,
which possessed the quality of closing instantly upon the occurrence of
the break, and which moreover was circulating through the gap at a rapid
rate. Very powerful effects were produced by discharges of this kind
with liquid interrupters, of which a number of different forms were
made. It was found that, as expected, a longer spark for a given length
of wire was obtainable in this way than by using air as an interrupting
device. Generally the speed, and therefore also the fluid pressure, was
limited by reason of the fluid friction, in the form of discharger
described, but the practically obtainable speed was more than sufficient
to produce a number of breaks suitable for the circuits ordinarily used.
In such instances the metal pulley P was provided with a few projections
inwardly, and a definite number of breaks was then produced which could
be computed from the speed of rotation of the pulley. Experiments were
also carried on with liquids of different insulating power with the view
of reducing the loss in the arc. When an insulating liquid is moderately
warmed, the loss in the arc is diminished.

A point of some importance was noted in experiments with various
discharges of this kind. It was found, for instance, that whereas the
conditions maintained in these forms were favorable for the production
of a great spark length, the current so obtained was not best suited to
the production of light effects. Experience undoubtedly has shown, that
for such purposes a harmonic rise and fall of the potential is
preferable. Be it that a solid is rendered incandescent, or
phosphorescent, or be it that energy is transmitted by condenser coating
through the glass, it is quite certain that a harmonically rising and
falling potential produces less destructive action, and that the vacuum
is more permanently maintained. This would be easily explained if it
were ascertained that the process going on in an exhausted vessel is of
an electrolytic nature.

In the diagrammatical sketch, Fig. 165, which has been already referred
to, the cases which are most likely to be met with in practice are
illustrated. One has at his disposal either direct or alternating
currents from a supply station. It is convenient for an experimenter in
an isolated laboratory to employ a machine G, such as illustrated,
capable of giving both kinds of currents. In such case it is also
preferable to use a machine with multiple circuits, as in many
experiments it is useful and convenient to have at one's disposal
currents of different phases. In the sketch, D represents the direct and
A the alternating circuit. In each of these, three branch circuits are
shown, all of which are provided with double line switches _s s s s s
s_. Consider first the direct current conversion; I_a_ represents the
simplest case. If the E. M. F. of the generator is sufficient to break
through a small air space, at least when the latter is warmed or
otherwise rendered poorly insulating, there is no difficulty in
maintaining a vibration with fair economy by judicious adjustment of the
capacity, self-induction and resistance of the circuit L containing the
devices _l l m_. The magnet N, S, can be in this case advantageously
combined with the air space. The discharger _d d_ with the magnet may be
placed either way, as indicated by the full or by the dotted lines. The
circuit I_a_ with the connections and devices is supposed to possess
dimensions such as are suitable for the maintenance of a vibration. But
usually the E. M. F. on the circuit or branch I_a_ will be something
like a 100 volts or so, and in this case it is not sufficient to break
through the gap. Many different means may be used to remedy this by
raising the E. M. F. across the gap. The simplest is probably to insert
a large self-induction coil in series with the circuit L. When the arc
is established, as by the discharger illustrated in Fig. 166, the magnet
blows the arc out the instant it is formed. Now the extra current of the
break, being of high E. M. F., breaks through the gap, and a path of low
resistance for the dynamo current being again provided, there is a
sudden rush of current from the dynamo upon the weakening or subsidence
of the extra current. This process is repeated in rapid succession, and
in this manner I have maintained oscillation with as low as 50 volts, or
even less, across the gap. But conversion on this plan is not to be
recommended on account of the too heavy currents through the gap and
consequent heating of the electrodes; besides, the frequencies obtained
in this way are low, owing to the high self-induction necessarily
associated with the circuit. It is very desirable to have the E. M. F.
as high as possible, first, in order to increase the economy of the
conversion, and, secondly, to obtain high frequencies. The difference of
potential in this electric oscillation is, of course, the equivalent of
the stretching force in the mechanical vibration of the spring. To
obtain very rapid vibration in a circuit of some inertia, a great
stretching force or difference of potential is necessary. Incidentally,
when the E. M. F. is very great, the condenser which is usually employed
in connection with the circuit need but have a small capacity, and many
other advantages are gained. With a view of raising the E. M. F. to a
many times greater value than obtainable from ordinary distribution
circuits, a rotating transformer _g_ is used, as indicated at II_a_,
Fig. 165, or else a separate high potential machine is driven by means
of a motor operated from the generator G. The latter plan is in fact
preferable, as changes are easier made. The connections from the high
tension winding are quite similar to those in branch I_a_ with the
exception that a condenser C, which should be adjustable, is connected
to the high tension circuit. Usually, also, an adjustable self-induction
coil in series with the circuit has been employed in these experiments.
When the tension of the currents is very high, the magnet ordinarily
used in connection with the discharger is of comparatively small value,
as it is quite easy to adjust the dimensions of the circuit so that
oscillation is maintained. The employment of a steady E. M. F. in the
high frequency conversion affords some advantages over the employment of
alternating E. M. F., as the adjustments are much simpler and the action
can be easier controlled. But unfortunately one is limited by the
obtainable potential difference. The winding also breaks down easily in
consequence of the sparks which form between the sections of the
armature or commutator when a vigorous oscillation takes place. Besides,
these transformers are expensive to build. It has been found by
experience that it is best to follow the plan illustrated at III_a_. In
this arrangement a rotating transformer _g_, is employed to convert the
low tension direct currents into low frequency alternating currents,
preferably also of small tension. The tension of the currents is then
raised in a stationary transformer T. The secondary S of this
transformer is connected to an adjustable condenser C which discharges
through the gap or discharger _d d_, placed in either of the ways
indicated, through the primary P of a disruptive discharge coil, the
high frequency current being obtained from the secondary S of this coil,
as described on previous occasions. This will undoubtedly be found the
cheapest and most convenient way of converting direct currents.

The three branches of the circuit A represent the usual cases met in
practice when alternating currents are converted. In Fig. 1_b_ a
condenser C, generally of large capacity, is connected to the circuit L
containing the devices _l l_, _m m_. The devices _m m_ are supposed to
be of high self-induction so as to bring the frequency of the circuit
more or less to that of the dynamo. In this instance the discharger _d
d_ should best have a number of makes and breaks per second equal to
twice the frequency of the dynamo. If not so, then it should have at
least a number equal to a multiple or even fraction of the dynamo
frequency. It should be observed, referring to I_b_, that the conversion
to a high potential is also effected when the discharger _d d_, which is
shown in the sketch, is omitted. But the effects which are produced by
currents which rise instantly to high values, as in a disruptive
discharge, are entirely different from those produced by dynamo currents
which rise and fall harmonically. So, for instance, there might be in a
given case a number of makes and breaks at _d d_ equal to just twice the
frequency of the dynamo, or in other words, there may be the same number
of fundamental oscillations as would be produced without the discharge
gap, and there might even not be any quicker superimposed vibration; yet
the differences of potential at the various points of the circuit, the
impedance and other phenomena, dependent upon the rate of change, will
bear no similarity in the two cases. Thus, when working with currents
discharging disruptively, the element chiefly to be considered is not
the frequency, as a student might be apt to believe, but the rate of
change per unit of time. With low frequencies in a certain measure the
same effects may be obtained as with high frequencies, provided the rate
of change is sufficiently great. So if a low frequency current is raised
to a potential of, say, 75,000 volts, and the high tension current
passed through a series of high resistance lamp filaments, the
importance of the rarefied gas surrounding the filament is clearly
noted, as will be seen later; or, if a low frequency current of several
thousand amperes is passed through a metal bar, striking phenomena of
impedance are observed, just as with currents of high frequencies. But
it is, of course, evident that with low frequency currents it is
impossible to obtain such rates of change per unit of time as with high
frequencies, hence the effects produced by the latter are much more
prominent. It is deemed advisable to make the preceding remarks,
inasmuch as many more recently described effects have been unwittingly
identified with high frequencies. Frequency alone in reality does not
mean anything, except when an undisturbed harmonic oscillation is
considered.

In the branch III_b_ a similar disposition to that in I_b_ is
illustrated, with the difference that the currents discharging through
the gap _d d_ are used to induce currents in the secondary S of a
transformer T. In such case the secondary should be provided with an
adjustable condenser for the purpose of tuning it to the primary.

II_b_ illustrates a plan of alternate current high frequency conversion
which is most frequently used and which is found to be most convenient.
This plan has been dwelt upon in detail on previous occasions and need
not be described here.

Some of these results were obtained by the use of a high frequency
alternator. A description of such machines will be found in my original
paper before the American Institute of Electrical Engineers, and in
periodicals of that period, notably in THE ELECTRICAL ENGINEER of March
18, 1891.

I will now proceed with the experiments.


ON PHENOMENA PRODUCED BY ELECTROSTATIC FORCE.

The first class of effects I intend to show you are effects produced by
electrostatic force. It is the force which governs the the motion of the
atoms, which causes them to collide and develop the life-sustaining
energy of heat and light, and which causes them to aggregate in an
infinite variety of ways, according to Nature's fanciful designs, and to
form all these wondrous structures we perceive around us; it is, in
fact, if our present views be true, the most important force for us to
consider in Nature. As the term _electrostatic_ might imply a steady
electric condition, it should be remarked, that in these experiments the
force is not constant, but varies at a rate which may be considered
moderate, about one million times a second, or thereabouts. This enables
me to produce many effects which are not producible with an unvarying
force.

When two conducting bodies are insulated and electrified, we say that an
electrostatic force is acting between them. This force manifests itself
in attractions, repulsions and stresses in the bodies and space or
medium without. So great may be the strain exerted in the air, or
whatever separates the two conducting bodies, that it may break down,
and we observe sparks or bundles of light or streamers, as they are
called. These streamers form abundantly when the force through the air
is rapidly varying. I will illustrate this action of electrostatic force
in a novel experiment in which I will employ the induction coil before
referred to. The coil is contained in a trough filled with oil, and
placed under the table. The two ends of the secondary wire pass through
the two thick columns of hard rubber which protrude to some height above
the table. It is necessary to insulate the ends or terminals of the
secondary heavily with hard rubber, because even dry wood is by far too
poor an insulator for these currents of enormous potential differences.
On one of the terminals of the coil, I have placed a large sphere of
sheet brass, which is connected to a larger insulated brass plate, in
order to enable me to perform the experiments under conditions, which,
as you will see, are more suitable for this experiment. I now set the
coil to work and approach the free terminal with a metallic object held
in my hand, this simply to avoid burns. As I approach the metallic
object to a distance of eight or ten inches, a torrent of furious sparks
breaks forth from the end of the secondary wire, which passes through
the rubber column. The sparks cease when the metal in my hand touches
the wire. My arm is now traversed by a powerful electric current,
vibrating at about the rate of one million times a second. All around me
the electrostatic force makes itself felt, and the air molecules and
particles of dust flying about are acted upon and are hammering
violently against my body. So great is this agitation of the particles,
that when the lights are turned out you may see streams of feeble light
appear on some parts of my body. When such a streamer breaks out on any
part of the body, it produces a sensation like the pricking of a needle.
Were the potentials sufficiently high and the frequency of the vibration
rather low, the skin would probably be ruptured under the tremendous
strain, and the blood would rush out with great force in the form of
fine spray or jet so thin as to be invisible, just as oil will when
placed on the positive terminal of a Holtz machine. The breaking through
of the skin though it may seem impossible at first, would perhaps occur,
by reason of the tissues under the skin being incomparably better
conducting. This, at least, appears plausible, judging from some
observations.

[Illustration: FIG. 169.]

I can make these streams of light visible to all, by touching with the
metallic object one of the terminals as before, and approaching my free
hand to the brass sphere, which is connected to the second terminal of
the coil. As the hand is approached, the air between it and the sphere,
or in the immediate neighborhood, is more violently agitated, and you
see streams of light now break forth from my finger tips and from the
whole hand (Fig. 169). Were I to approach the hand closer, powerful
sparks would jump from the brass sphere to my hand, which might be
injurious. The streamers offer no particular inconvenience, except that
in the ends of the finger tips a burning sensation is felt. They should
not be confounded with those produced by an influence machine, because
in many respects they behave differently. I have attached the brass
sphere and plate to one of the terminals in order to prevent the
formation of visible streamers on that terminal, also in order to
prevent sparks from jumping at a considerable distance. Besides, the
attachment is favorable for the working of the coil.

The streams of light which you have observed issuing from my hand are
due to a potential of about 200,000 volts, alternating in rather
irregular intervals, sometimes like a million times a second. A
vibration of the same amplitude, but four times as fast, to maintain
which over 3,000,000 volts would be required, would be more than
sufficient to envelop my body in a complete sheet of flame. But this
flame would not burn me up; quite contrarily, the probability is that I
would not be injured in the least. Yet a hundredth part of that energy,
otherwise directed, would be amply sufficient to kill a person.

The amount of energy which may thus be passed into the body of a person
depends on the frequency and potential of the currents, and by making
both of these very great, a vast amount of energy may be passed into the
body without causing any discomfort, except perhaps, in the arm, which
is traversed by a true conduction current. The reason why no pain in the
body is felt, and no injurious effect noted, is that everywhere, if a
current be imagined to flow through the body, the direction of its flow
would be at right angles to the surface; hence the body of the
experimenter offers an enormous section to the current, and the density
is very small, with the exception of the arm, perhaps, where the density
may be considerable. But if only a small fraction of that energy would
be applied in such a way that a current would traverse the body in the
same manner as a low frequency current, a shock would be received which
might be fatal. A direct or low frequency alternating current is fatal,
I think, principally because its distribution through the body is not
uniform, as it must divide itself in minute streamlets of great density,
whereby some organs are vitally injured. That such a process occurs I
have not the least doubt, though no evidence might apparently exist, or
be found upon examination. The surest to injure and destroy life, is a
continuous current, but the most painful is an alternating current of
very low frequency. The expression of these views, which are the result
of long continued experiment and observation, both with steady and
varying currents, is elicited by the interest which is at present taken
in this subject, and by the manifestly erroneous ideas which are daily
propounded in journals on this subject.

I may illustrate an effect of the electrostatic force by another
striking experiment, but before, I must call your attention to one or
two facts. I have said before, that when the medium between two
oppositely electrified bodies is strained beyond a certain limit it
gives way and, stated in popular language, the opposite electric charges
unite and neutralize each other. This breaking down of the medium occurs
principally when the force acting between the bodies is steady, or
varies at a moderate rate. Were the variation sufficiently rapid, such a
destructive break would not occur, no matter how great the force, for
all the energy would be spent in radiation, convection and mechanical
and chemical action. Thus the _spark_ length, or greatest distance which
a _spark_ will jump between the electrified bodies is the smaller, the
greater the variation or time rate of change. But this rule may be taken
to be true only in a general way, when comparing rates which are widely
different.

[Illustration: FIG. 170a.]

[Illustration: FIG. 170b.]

I will show you by an experiment the difference in the effect produced
by a rapidly varying and a steady or moderately varying force. I have
here two large circular brass plates _p p_ (Fig. 170_a_ and Fig.
170_b_), supported on movable insulating stands on the table, connected
to the ends of the secondary of a coil similar to the one used before. I
place the plates ten or twelve inches apart and set the coil to work.
You see the whole space between the plates, nearly two cubic feet,
filled with uniform light, Fig. 170_a_. This light is due to the
streamers you have seen in the first experiment, which are now much more
intense. I have already pointed out the importance of these streamers in
commercial apparatus and their still greater importance in some purely
scientific investigations. Often they are too weak to be visible, but
they always exist, consuming energy and modifying the action of the
apparatus. When intense, as they are at present, they produce ozone in
great quantity, and also, as Professor Crookes has pointed out, nitrous
acid. So quick is the chemical action that if a coil, such as this one,
is worked for a very long time it will make the atmosphere of a small
room unbearable, for the eyes and throat are attacked. But when
moderately produced, the streamers refresh the atmosphere wonderfully,
like a thunder-storm, and exercises unquestionably a beneficial effect.

In this experiment the force acting between the plates changes in
intensity and direction at a very rapid rate. I will now make the rate
of change per unit time much smaller. This I effect by rendering the
discharges through the primary of the induction coil less frequent, and
also by diminishing the rapidity of the vibration in the secondary. The
former result is conveniently secured by lowering the E. M. F. over the
air gap in the primary circuit, the latter by approaching the two brass
plates to a distance of about three or four inches. When the coil is set
to work, you see no streamers or light between the plates, yet the
medium between them is under a tremendous strain. I still further
augment the strain by raising the E. M. F. in the primary circuit, and
soon you see the air give way and the hall is illuminated by a shower of
brilliant and noisy sparks, Fig. 170_b_. These sparks could be produced
also with unvarying force; they have been for many years a familiar
phenomenon, though they were usually obtained from an entirely different
apparatus. In describing these two phenomena so radically different in
appearance, I have advisedly spoken of a "force" acting between the
plates. It would be in accordance with accepted views to say, that there
was an "alternating E. M. F," acting between the plates. This term is
quite proper and applicable in all cases where there is evidence of at
least a possibility of an essential inter-dependence of the electric
state of the plates, or electric action in their neighborhood. But if
the plates were removed to an infinite distance, or if at a finite
distance, there is no probability or necessity whatever for such
dependence. I prefer to use the term "electrostatic force," and to say
that such a force is acting around each plate or electrified insulated
body in general. There is an inconvenience in using this expression as
the term incidentally means a steady electric condition; but a proper
nomenclature will eventually settle this difficulty.

I now return to the experiment to which I have already alluded, and with
which I desire to illustrate a striking effect produced by a rapidly
varying electrostatic force. I attach to the end of the wire, _l_ (Fig.
171), which is in connection with one of the terminals of the secondary
of the induction coil, an exhausted bulb _b_. This bulb contains a thin
carbon filament _f_, which is fastened to a platinum wire _w_, sealed in
the glass and leading outside of the bulb, where it connects to the wire
_l_. The bulb may be exhausted to any degree attainable with ordinary
apparatus. Just a moment before, you have witnessed the breaking down of
the air between the charged brass plates. You know that a plate of
glass, or any other insulating material, would break down in like
manner. Had I therefore a metallic coating attached to the outside of
the bulb, or placed near the same, and were this coating connected to
the other terminal of the coil, you would be prepared to see the glass
give way if the strain were sufficiently increased. Even were the
coating not connected to the other terminal, but to an insulated plate,
still, if you have followed recent developments, you would naturally
expect a rupture of the glass.

[Illustration: FIG. 171.]

[Illustration: FIG. 172a.]

[Illustration: FIG. 172b.]

But it will certainly surprise you to note that under the action of the
varying electrostatic force, the glass gives way when all other bodies
are removed from the bulb. In fact, all the surrounding bodies we
perceive might be removed to an infinite distance without affecting the
result in the slightest. When the coil is set to work, the glass is
invariably broken through at the seal, or other narrow channel, and the
vacuum is quickly impaired. Such a damaging break would not occur with
a steady force, even if the same were many times greater. The break is
due to the agitation of the molecules of the gas within the bulb, and
outside of the same. This agitation, which is generally most violent in
the narrow pointed channel near the seal, causes a heating and rupture
of the glass. This rupture, would, however, not occur, not even with a
varying force, if the medium filling the inside of the bulb, and that
surrounding it, were perfectly homogeneous. The break occurs much
quicker if the top of the bulb is drawn out into a fine fibre. In bulbs
used with these coils such narrow, pointed channels must therefore be
avoided.

When a conducting body is immersed in air, or similar insulating medium,
consisting of, or containing, small freely movable particles capable of
being electrified, and when the electrification of the body is made to
undergo a very rapid change--which is equivalent to saying that the
electrostatic force acting around the body is varying in intensity,--the
small particles are attracted and repelled, and their violent impacts
against the body may cause a mechanical motion of the latter. Phenomena
of this kind are noteworthy, inasmuch as they have not been observed
before with apparatus such as has been commonly in use. If a very light
conducting sphere be suspended on an exceedingly fine wire, and charged
to a steady potential, however high, the sphere will remain at rest.
Even if the potential would be rapidly varying, provided that the small
particles of matter, molecules or atoms, are evenly distributed, no
motion of the sphere should result. But if one side of the conducting
sphere is covered with a thick insulating layer, the impacts of the
particles will cause the sphere to move about, generally in irregular
curves, Fig. 172_a_. In like manner, as I have shown on a previous
occasion, a fan of sheet metal, Fig. 172_b_, covered partially with
insulating material as indicated, and placed upon the terminal of the
coil so as to turn freely on it, is spun around.

All these phenomena you have witnessed and others which will be shown
later, are due to the presence of a medium like air, and would not occur
in a continuous medium. The action of the air may be illustrated still
better by the following experiment. I take a glass tube _t_, Fig. 173,
of about an inch in diameter, which has a platinum wire _w_ sealed in
the lower end, and to which is attached a thin lamp filament _f_. I
connect the wire with the terminal of the coil and set the coil to work.
The platinum wire is now electrified positively and negatively in rapid
succession and the wire and air inside of the tube is rapidly heated by
the impacts of the particles, which may be so violent as to render the
filament incandescent. But if I pour oil in the tube, just as soon as
the wire is covered with the oil, all action apparently ceases and there
is no marked evidence of heating. The reason of this is that the oil is
a practically continuous medium. The displacements in such a continuous
medium are, with these frequencies, to all appearance incomparably
smaller than in air, hence the work performed in such a medium is
insignificant. But oil would behave very differently with frequencies
many times as great, for even though the displacements be small, if the
frequency were much greater, considerable work might be performed in the
oil.

[Illustration: FIG. 173.]

[Illustration: FIG. 174.]

The electrostatic attractions and repulsions between bodies of
measurable dimensions are, of all the manifestations of this force, the
first so-called _electrical_ phenomena noted. But though they have been
known to us for many centuries, the precise nature of the mechanism
concerned in these actions is still unknown to us, and has not been even
quite satisfactorily explained. What kind of mechanism must that be? We
cannot help wondering when we observe two magnets attracting and
repelling each other with a force of hundreds of pounds with apparently
nothing between them. We have in our commercial dynamos magnets capable
of sustaining in mid-air tons of weight. But what are even these forces
acting between magnets when compared with the tremendous attractions and
repulsions produced by electrostatic force, to which there is apparently
no limit as to intensity. In lightning discharges bodies are often
charged to so high a potential that they are thrown away with
inconceivable force and torn asunder or shattered into fragments. Still
even such effects cannot compare with the attractions and repulsions
which exist between charged molecules or atoms, and which are sufficient
to project them with speeds of many kilometres a second, so that under
their violent impact bodies are rendered highly incandescent and are
volatilized. It is of special interest for the thinker who inquires into
the nature of these forces to note that whereas the actions between
individual molecules or atoms occur seemingly under any conditions, the
attractions and repulsions of bodies of measurable dimensions imply a
medium possessing insulating properties. So, if air, either by being
rarefied or heated, is rendered more or less conducting, these actions
between two electrified bodies practically cease, while the actions
between the individual atoms continue to manifest themselves.

An experiment may serve as an illustration and as a means of bringing
out other features of interest. Some time ago I showed that a lamp
filament or wire mounted in a bulb and connected to one of the terminals
of a high tension secondary coil is set spinning, the top of the
filament generally describing a circle. This vibration was very
energetic when the air in the bulb was at ordinary pressure and became
less energetic when the air in the bulb was strongly compressed. It
ceased altogether when the air was exhausted so as to become
comparatively good conducting. I found at that time that no vibration
took place when the bulb was very highly exhausted. But I conjectured
that the vibration which I ascribed to the electrostatic action between
the walls of the bulb and the filament should take place also in a
highly exhausted bulb. To test this under conditions which were more
favorable, a bulb like the one in Fig. 174, was constructed. It
comprised a globe _b_, in the neck of which was sealed a platinum wire
_w_ carrying a thin lamp filament _f_. In the lower part of the globe a
tube _t_ was sealed so as to surround the filament. The exhaustion was
carried as far as it was practicable with the apparatus employed.

This bulb verified my expectation, for the filament was set spinning
when the current was turned on, and became incandescent. It also showed
another interesting feature, bearing upon the preceding remarks, namely,
when the filament had been kept incandescent some time, the narrow tube
and the space inside were brought to an elevated temperature, and as the
gas in the tube then became conducting, the electrostatic attraction
between the glass and the filament became very weak or ceased, and the
filament came to rest. When it came to rest it would glow far more
intensely. This was probably due to its assuming the position in the
centre of the tube where the molecular bombardment was most intense, and
also partly to the fact that the individual impacts were more violent
and that no part of the supplied energy was converted into mechanical
movement. Since, in accordance with accepted views, in this experiment
the incandescence must be attributed to the impacts of the particles,
molecules or atoms in the heated space, these particles must therefore,
in order to explain such action, be assumed to behave as independent
carriers of electric charges immersed in an insulating medium; yet there
is no attractive force between the glass tube and the filament because
the space in the tube is, as a whole, conducting.

It is of some interest to observe in this connection that whereas the
attraction between two electrified bodies may cease owing to the
impairing of the insulating power of the medium in which they are
immersed, the repulsion between the bodies may still be observed. This
may be explained in a plausible way. When the bodies are placed at some
distance in a poorly conducting medium, such as slightly warmed or
rarefied air, and are suddenly electrified, opposite electric charges
being imparted to them, these charges equalize more or less by leakage
through the air. But if the bodies are similarly electrified, there is
less opportunity afforded for such dissipation, hence the repulsion
observed in such case is greater than the attraction. Repulsive actions
in a gaseous medium are however, as Prof. Crookes has shown, enhanced by
molecular bombardment.


ON CURRENT OR DYNAMIC ELECTRICITY PHENOMENA.

So far, I have considered principally effects produced by a varying
electrostatic force in an insulating medium, such as air. When such a
force is acting upon a conducting body of measurable dimensions, it
causes within the same, or on its surface, displacements of the
electricity and gives rise to electric currents, and these produce
another kind of phenomena, some of which I shall presently endeavor to
illustrate. In presenting this second class of electrical effects, I
will avail myself principally of such as are producible without any
return circuit, hoping to interest you the more by presenting these
phenomena in a more or less novel aspect.

It has been a long time customary, owing to the limited experience with
vibratory currents, to consider an electric current as something
circulating in a closed conducting path. It was astonishing at first to
realize that a current may flow through the conducting path even if the
latter be interrupted, and it was still more surprising to learn, that
sometimes it may be even easier to make a current flow under such
conditions than through a closed path. But that old idea is gradually
disappearing, even among practical men, and will soon be entirely
forgotten.

[Illustration: FIG. 175.]

If I connect an insulated metal plate P, Fig. 175, to one of the
terminals T of the induction coil by means of a wire, though this plate
be very well insulated, a current passes through the wire when the coil
is set to work. First I wish to give you evidence that there _is_ a
current passing through the connecting wire. An obvious way of
demonstrating this is to insert between the terminal of the coil and the
insulated plate a very thin platinum or german silver wire _w_ and bring
the latter to incandescence or fusion by the current. This requires a
rather large plate or else current impulses of very high potential and
frequency. Another way is to take a coil C, Fig. 175, containing many
turns of thin insulated wire and to insert the same in the path of the
current to the plate. When I connect one of the ends of the coil to the
wire leading to another insulated plate P_{1}, and its other end to the
terminal T_{1} of the induction coil, and set the latter to work, a
current passes through the inserted coil C and the existence of the
current may be made manifest in various ways. For instance, I insert an
iron core _i_ within the coil. The current being one of very high
frequency, will, if it be of some strength, soon bring the iron core to
a noticeably higher temperature, as the hysteresis and current losses
are great with such high frequencies. One might take a core of some
size, laminated or not, it would matter little; but ordinary iron wire
1/16th or 1/8th of an inch thick is suitable for the purpose. While the
induction coil is working, a current traverses the inserted coil and
only a few moments are sufficient to bring the iron wire _i_ to an
elevated temperature sufficient to soften the sealing-wax _s_, and cause
a paper washer _p_ fastened by it to the iron wire to fall off. But with
the apparatus such as I have here, other, much more interesting,
demonstrations of this kind can be made. I have a secondary S, Fig 176,
of coarse wire, wound upon a coil similar to the first. In the preceding
experiment the current through the coil C, Fig. 175, was very small, but
there being many turns a strong heating effect was, nevertheless,
produced in the iron wire. Had I passed that current through a conductor
in order to show the heating of the latter, the current might have been
too small to produce the effect desired. But with this coil provided
with a secondary winding, I can now transform the feeble current of high
tension which passes through the primary P into a strong secondary
current of low tension, and this current will quite certainly do what I
expect. In a small glass tube (_t_, Fig. 176), I have enclosed a coiled
platinum wire, _w_, this merely in order to protect the wire. On each
end of the glass tube is sealed a terminal of stout wire to which one of
the ends of the platinum wire _w_, is connected. I join the terminals of
the secondary coil to these terminals and insert the primary _p_,
between the insulated plate P_{1}, and the terminal T_{1}, of the
induction coil as before. The latter being set to work, instantly the
platinum wire _w_ is rendered incandescent and can be fused, even if it
be very thick.

[Illustration: FIG. 176.]

Instead of the platinum wire I now take an ordinary 50-volt 16 C. P.
lamp. When I set the induction coil in operation the lamp filament is
brought to high incandescence. It is, however, not necessary to use the
insulated plate, for the lamp (_l_, Fig. 177) is rendered incandescent
even if the plate P_{1} be disconnected. The secondary may also be
connected to the primary as indicated by the dotted line in Fig. 177, to
do away more or less with the electrostatic induction or to modify the
action otherwise.

[Illustration: FIG. 177.]

I may here call attention to a number of interesting observations with
the lamp. First, I disconnect one of the terminals of the lamp from the
secondary S. When the induction coil plays, a glow is noted which fills
the whole bulb. This glow is due to electrostatic induction. It
increases when the bulb is grasped with the hand, and the capacity of
the experimenter's body thus added to the secondary circuit. The
secondary, in effect, is equivalent to a metallic coating, which would
be placed near the primary. If the secondary, or its equivalent, the
coating, were placed symmetrically to the primary, the electrostatic
induction would be nil under ordinary conditions, that is, when a
primary return circuit is used, as both halves would neutralize each
other. The secondary _is_ in fact placed symmetrically to the primary,
but the action of both halves of the latter, when only one of its ends
is connected to the induction coil, is not exactly equal; hence
electrostatic induction takes place, and hence the glow in the bulb. I
can nearly equalize the action of both halves of the primary by
connecting the other, free end of the same to the insulated plate, as in
the preceding experiment. When the plate is connected, the glow
disappears. With a smaller plate it would not entirely disappear and
then it would contribute to the brightness of the filament when the
secondary is closed, by warming the air in the bulb.

[Illustration: FIG. 178a.]

[Illustration: FIG. 178b.]

[Illustration: FIG. 179a.]

[Illustration: FIG. 179b.]

To demonstrate another interesting feature, I have adjusted the coils
used in a certain way. I first connect both the terminals of the lamp to
the secondary, one end of the primary being connected to the terminal
T_{1} of the induction coil and the other to the insulated plate P_{1}
as before. When the current is turned on, the lamp glows brightly, as
shown in Fig. 178_b_, in which C is a fine wire coil and S a coarse wire
secondary wound upon it. If the insulated plate P_{1} is disconnected,
leaving one of the ends _a_ of the primary insulated, the filament
becomes dark or generally it diminishes in brightness (Fig. 178_a_).
Connecting again the plate P_{1} and raising the frequency of the
current, I make the filament quite dark or barely red (Fig. 179_b_).
Once more I will disconnect the plate. One will of course infer that
when the plate is disconnected, the current through the primary will be
weakened, that therefore the E. M. F. will fall in the secondary S, and
that the brightness of the lamp will diminish. This might be the case
and the result can be secured by an easy adjustment of the coils; also
by varying the frequency and potential of the currents. But it is
perhaps of greater interest to note, that the lamp increases in
brightness when the plate is disconnected (Fig. 179_a_). In this case
all the energy the primary receives is now sunk into it, like the charge
of a battery in an ocean cable, but most of that energy is recovered
through the secondary and used to light the lamp. The current traversing
the primary is strongest at the end _b_ which is connected to the
terminal T_{1} of the induction coil, and diminishes in strength towards
the remote end _a_. But the dynamic inductive effect exerted upon the
secondary S is now greater than before, when the suspended plate was
connected to the primary. These results might have been produced by a
number of causes. For instance, the plate P_{1} being connected, the
reaction from the coil C may be such as to diminish the potential at the
terminal T_{1} of the induction coil, and therefore weaken the current
through the primary of the coil C. Or the disconnecting of the plate
may diminish the capacity effect with relation to the primary of the
latter coil to such an extent that the current through it is diminished,
though the potential at the terminal T_{1} of the induction coil may be
the same or even higher. Or the result might have been produced by the
change of phase of the primary and secondary currents and consequent
reaction. But the chief determining factor is the relation of the
self-induction and capacity of coil C and plate P_{1} and the frequency
of the currents. The greater brightness of the filament in Fig. 179_a_,
is, however, in part due to the heating of the rarefied gas in the lamp
by electrostatic induction, which, as before remarked, is greater when
the suspended plate is disconnected.

Still another feature of some interest I may here bring to your
attention. When the insulated plate is disconnected and the secondary of
the coil opened, by approaching a small object to the secondary, but
very small sparks can be drawn from it, showing that the electrostatic
induction is small in this case. But upon the secondary being closed
upon itself or through the lamp, the filament glowing brightly, strong
sparks are obtained from the secondary. The electrostatic induction is
now much greater, because the closed secondary determines a greater flow
of current through the primary and principally through that half of it
which is connected to the induction coil. If now the bulb be grasped
with the hand, the capacity of the secondary with reference to the
primary is augmented by the experimenter's body and the luminosity of
the filament is increased, the incandescence now being due partly to the
flow of current through the filament and partly to the molecular
bombardment of the rarefied gas in the bulb.

The preceding experiments will have prepared one for the next following
results of interest, obtained in the course of these investigations.
Since I can pass a current through an insulated wire merely by
connecting one of its ends to the source of electrical energy, since I
can induce by it another current, magnetize an iron core, and, in short,
perform all operations as though a return circuit were used, clearly I
can also drive a motor by the aid of only one wire. On a former occasion
I have described a simple form of motor comprising a single exciting
coil, an iron core and disc. Fig. 180 illustrates a modified way of
operating such an alternate current motor by currents induced in a
transformer connected to one lead, and several other arrangements of
circuits for operating a certain class of alternating motors founded on
the action of currents of differing phase. In view of the present state
of the art it is thought sufficient to describe these arrangements in a
few words only. The diagram, Fig. 180 II., shows a primary coil P,
connected with one of its ends to the line L leading from a high tension
transformer terminal T_{1}. In inductive relation to this primary P is a
secondary S of coarse wire in the circuit of which is a coil _c_. The
currents induced in the secondary energize the iron core _i_, which is
preferably, but not necessarily, subdivided, and set the metal disc _d_
in rotation. Such a motor M_{2} as diagramatically shown in Fig. 180
II., has been called a "magnetic lag motor," but this expression may be
objected to by those who attribute the rotation of the disc to eddy
currents circulating in minute paths when the core _i_ is finally
subdivided. In order to operate such a motor effectively on the plan
indicated, the frequencies should not be too high, not more than four or
five thousand, though the rotation is produced even with ten thousand
per second, or more.

In Fig. 180 I., a motor M_{1} having two energizing circuits, A and B,
is diagrammatically indicated. The circuit A is connected to the line L
and in series with it is a primary P, which may have its free end
connected to an insulated plate P_{1}, such connection being indicated
by the dotted lines. The other motor circuit B is connected to the
secondary S which is in inductive relation to the primary P. When the
transformer terminal T_{1} is alternately electrified, currents traverse
the open line L and also circuit A and primary P. The currents through
the latter induce secondary currents in the circuit S, which pass
through the energizing coil B of the motor. The currents through the
secondary S and those through the primary P differ in phase 90 degrees,
or nearly so, and are capable of rotating an armature placed in
inductive relation to the circuits A and B.

In Fig. 180 III., a similar motor M_{3} with two energizing circuits
A_{1} and B_{1} is illustrated. A primary P, connected with one of its
ends to the line L has a secondary S, which is preferably wound for a
tolerably high E. M. F., and to which the two energizing circuits of the
motor are connected, one directly to the ends of the secondary and the
other through a condenser C, by the action of which the currents
traversing the circuit A_{1} and B_{1} are made to differ in phase.

[Illustration: FIG. 180.]

[Illustration: FIG. 181.]

[Illustration: FIG. 182.]

In Fig. 180 IV., still another arrangement is shown. In this case two
primaries P_{1} and P_{2} are connected to the line L, one through a
condenser C of small capacity, and the other directly. The primaries are
provided with secondaries S_{1} and S_{2} which are in series with the
energizing circuits, A_{2} and B_{2} and a motor M_{3}, the condenser C
again serving to produce the requisite difference in the phase of the
currents traversing the motor circuits. As such phase motors with two or
more circuits are now well known in the art, they have been here
illustrated diagrammatically. No difficulty whatever is found in
operating a motor in the manner indicated, or in similar ways; and
although such experiments up to this day present only scientific
interest, they may at a period not far distant, be carried out with
practical objects in view.

It is thought useful to devote here a few remarks to the subject of
operating devices of all kinds by means of only one leading wire. It is
quite obvious, that when high-frequency currents are made use of, ground
connections are--at least when the E. M. F. of the currents is
great--better than a return wire. Such ground connections are
objectionable with steady or low frequency currents on account of
destructive chemical actions of the former and disturbing influences
exerted by both on the neighboring circuits; but with high frequencies
these actions practically do not exist. Still, even ground connections
become superfluous when the E. M. F. is very high, for soon a condition
is reached, when the current may be passed more economically through
open, than through closed, conductors. Remote as might seem an
industrial application of such single wire transmission of energy to one
not experienced in such lines of experiment, it will not seem so to
anyone who for some time has carried on investigations of such nature.
Indeed I cannot see why such a plan should not be practicable. Nor
should it be thought that for carrying out such a plan currents of very
high frequency are expressly required, for just as soon as potentials of
say 30,000 volts are used, the single wire transmission may be effected
with low frequencies, and experiments have been made by me from which
these inferences are made.

When the frequencies are very high it has been found in laboratory
practice quite easy to regulate the effects in the manner shown in
diagram Fig. 181. Here two primaries P and P_{1} are shown, each
connected with one of its ends to the line L and with the other end to
the condenser plates C and C, respectively. Near these are placed other
condenser plates C_{1} and C_{1}, the former being connected to the line
L and the latter to an insulated larger plate P_{2}. On the primaries
are wound secondaries S and S_{1}, of coarse wire, connected to the
devices _d_ and _l_ respectively. By varying the distances of the
condenser plates C and C_{1}, and C and C_{1} the currents through the
secondaries S and S_{1} are varied in intensity. The curious feature is
the great sensitiveness, the slightest change in the distance of the
plates producing considerable variations in the intensity or strength of
the currents. The sensitiveness may be rendered extreme by making the
frequency such, that the primary itself, without any plate attached to
its free end, satisfies, in conjunction with the closed secondary, the
condition of resonance. In such condition an extremely small change in
the capacity of the free terminal produces great variations. For
instance, I have been able to adjust the conditions so that the mere
approach of a person to the coil produces a considerable change in the
brightness of the lamps attached to the secondary. Such observations and
experiments possess, of course, at present, chiefly scientific interest,
but they may soon become of practical importance.

Very high frequencies are of course not practicable with motors on
account of the necessity of employing iron cores. But one may use sudden
discharges of low frequency and thus obtain certain advantages of
high-frequency currents without rendering the iron core entirely
incapable of following the changes and without entailing a very great
expenditure of energy in the core. I have found it quite practicable to
operate with such low frequency disruptive discharges of condensers,
alternating-current motors. A certain class of such motors which I
advanced a few years ago, which contain closed secondary circuits, will
rotate quite vigorously when the discharges are directed through the
exciting coils. One reason that such a motor operates so well with these
discharges is that the difference of phase between the primary and
secondary currents is 90 degrees, which is generally not the case with
harmonically rising and falling currents of low frequency. It might not
be without interest to show an experiment with a simple motor of this
kind, inasmuch as it is commonly thought that disruptive discharges are
unsuitable for such purposes. The motor is illustrated in Fig. 182. It
comprises a rather large iron core _i_ with slots on the top into which
are embedded thick copper washers _c c_. In proximity to the core is a
freely-movable metal disc D. The core is provided with a primary
exciting coil C_{1} the ends _a_ and _b_ of which are connected to the
terminals of the secondary S of an ordinary transformer, the primary P
of the latter being connected to an alternating distribution circuit or
generator G of low or moderate frequency. The terminals of the secondary
S are attached to a condenser C which discharges through an air gap _d
d_ which may be placed in series or shunt to the coil C_{1}. When the
conditions are properly chosen the disc D rotates with considerable
effort and the iron core _i_ does not get very perceptibly hot. With
currents from a high-frequency alternator, on the contrary, the core
gets rapidly hot and the disc rotates with a much smaller effort. To
perform the experiment properly it should be first ascertained that the
disc D is not set in rotation when the discharge is not occurring at _d
d_. It is preferable to use a large iron core and a condenser of large
capacity so as to bring the superimposed quicker oscillation to a very
low pitch or to do away with it entirely. By observing certain
elementary rules I have also found it practicable to operate ordinary
series or shunt direct-current motors with such disruptive discharges,
and this can be done with or without a return wire.


IMPEDANCE PHENOMENA.

Among the various current phenomena observed, perhaps the most
interesting are those of impedance presented by conductors to currents
varying at a rapid rate. In my first paper before the American Institute
of Electrical Engineers, I have described a few striking observations of
this kind. Thus I showed that when such currents or sudden discharges
are passed through a thick metal bar there may be points on the bar only
a few inches apart, which have a sufficient potential difference between
them to maintain at bright incandescence an ordinary filament lamp. I
have also described the curious behavior of rarefied gas surrounding a
conductor, due to such sudden rushes of current. These phenomena have
since been more carefully studied and one or two novel experiments of
this kind are deemed of sufficient interest to be described here.

Referring to Fig. 183_a_, B and B_{1} are very stout copper bars
connected at their lower ends to plates C and C_{1}, respectively, of a
condenser, the opposite plates of the latter being connected to the
terminals of the secondary S of a high-tension transformer, the primary
P of which is supplied with alternating currents from an ordinary
low-frequency dynamo G or distribution circuit. The condenser
discharges through an adjustable gap _d d_ as usual. By establishing a
rapid vibration it was found quite easy to perform the following curious
experiment. The bars B and B_{1} were joined at the top by a low-voltage
lamp l_{3}; a little lower was placed by means of clamps _c c_, a
50-volt lamp l_{2}; and still lower another 100-volt lamp l_{1}; and
finally, at a certain distance below the latter lamp, an exhausted tube
T. By carefully determining the positions of these devices it was found
practicable to maintain them all at their proper illuminating power. Yet
they were all connected in multiple arc to the two stout copper bars and
required widely different pressures. This experiment requires of course
some time for adjustment but is quite easily performed.

[Illustration: FIGS. 183a, 183b and 183c.]

In Figs. 183_b_ and 183_c_, two other experiments are illustrated which,
unlike the previous experiment, do not require very careful adjustments.
In Fig. 183_b_, two lamps, l_{1} and l_{2}, the former a 100-volt
and the latter a 50-volt are placed in certain positions as indicated,
the 100-volt lamp being below the 50-volt lamp. When the arc is playing
at _d d_ and the sudden discharges are passed through the bars B B_{1},
the 50-volt lamp will, as a rule, burn brightly, or at least this result
is easily secured, while the 100-volt lamp will burn very low or remain
quite dark, Fig. 183_b_. Now the bars B B_{1} may be joined at the top
by a thick cross bar B_{2} and it is quite easy to maintain the 100-volt
lamp at full candle-power while the 50-volt lamp remains dark, Fig.
183_c_. These results, as I have pointed out previously, should not be
considered to be due exactly to frequency but rather to the time rate of
change which may be great, even with low frequencies. A great many other
results of the same kind, equally interesting, especially to those who
are only used to manipulate steady currents, may be obtained and they
afford precious clues in investigating the nature of electric currents.

In the preceding experiments I have already had occasion to show some
light phenomena and it would now be proper to study these in particular;
but to make this investigation more complete I think it necessary to
make first a few remarks on the subject of electrical resonance which
has to be always observed in carrying out these experiments.


ON ELECTRICAL RESONANCE.

The effects of resonance are being more and more noted by engineers and
are becoming of great importance in the practical operation of apparatus
of all kinds with alternating currents. A few general remarks may
therefore be made concerning these effects. It is clear, that if we
succeed in employing the effects of resonance practically in the
operation of electric devices the return wire will, as a matter of
course, become unnecessary, for the electric vibration may be conveyed
with one wire just as well as, and sometimes even better than, with two.
The question first to answer is, then, whether pure resonance effects
are producible. Theory and experiment both show that such is impossible
in Nature, for as the oscillation becomes more and more vigorous, the
losses in the vibrating bodies and environing media rapidly increase and
necessarily check the vibration which otherwise would go on increasing
forever. It is a fortunate circumstance that pure resonance is not
producible, for if it were there is no telling what dangers might not
lie in wait for the innocent experimenter. But to a certain degree
resonance is producible, the magnitude of the effects being limited by
the imperfect conductivity and imperfect elasticity of the media or,
generally stated, by frictional losses. The smaller these losses, the
more striking are the effects. The same is the case in mechanical
vibration. A stout steel bar may be set in vibration by drops of water
falling upon it at proper intervals; and with glass, which is more
perfectly elastic, the resonance effect is still more remarkable, for a
goblet may be burst by singing into it a note of the proper pitch. The
electrical resonance is the more perfectly attained, the smaller the
resistance or the impedance of the conducting path and the more perfect
the dielectric. In a Leyden jar discharging through a short stranded
cable of thin wires these requirements are probably best fulfilled, and
the resonance effects are therefore very prominent. Such is not the case
with dynamo machines, transformers and their circuits, or with
commercial apparatus in general in which the presence of iron cores
complicates the action or renders it impossible. In regard to Leyden
jars with which resonance effects are frequently demonstrated, I would
say that the effects observed are often _attributed_ but are seldom
_due_ to true resonance, for an error is quite easily made in this
respect. This may be undoubtedly demonstrated by the following
experiment. Take, for instance, two large insulated metallic plates or
spheres which I shall designate A and B; place them at a certain small
distance apart and charge them from a frictional or influence machine to
a potential so high that just a slight increase of the difference of
potential between them will cause the small air or insulating space to
break down. This is easily reached by making a few preliminary trials.
If now another plate--fastened on an insulating handle and connected by
a wire to one of the terminals of a high tension secondary of an
induction coil, which is maintained in action by an alternator
(preferably high frequency)--is approached to one of the charged bodies
A or B, so as to be nearer to either one of them, the discharge will
invariably occur between them; at least it will, if the potential of the
coil in connection with the plate is sufficiently high. But the
explanation of this will soon be found in the fact that the approached
plate acts inductively upon the bodies A and B and causes a spark to
pass between them. When this spark occurs, the charges which were
previously imparted to these bodies from the influence machine, must
needs be lost, since the bodies are brought in electrical connection
through the arc formed. Now this arc is formed whether there be
resonance or not. But even if the spark would not be produced, still
there is an alternating E. M. F. set up between the bodies when the
plate is brought near one of them; therefore the approach of the plate,
if it _does_ not always actually, will, at any rate, _tend_ to break
down the air space by inductive action. Instead of the spheres or plates
A and B we may take the coatings of a Leyden jar with the same result,
and in place of the machine,--which is a high frequency alternator
preferably, because it is more suitable for the experiment and also for
the argument,--we may take another Leyden jar or battery of jars. When
such jars are discharging through a circuit of low resistance the same
is traversed by currents of very high frequency. The plate may now be
connected to one of the coatings of the second jar, and when it is
brought near to the first jar just previously charged to a high
potential from an influence machine, the result is the same as before,
and the first jar will discharge through a small air space upon the
second being caused to discharge. But both jars and their circuits need
not be tuned any closer than a basso profundo is to the note produced by
a mosquito, as small sparks will be produced through the air space, or
at least the latter will be considerably more strained owing to the
setting up of an alternating E. M. F. by induction, which takes place
when one of the jars begins to discharge. Again another error of a
similar nature is quite easily made. If the circuits of the two jars are
run parallel and close together, and the experiment has been performed
of discharging one by the other, and now a coil of wire be added to one
of the circuits whereupon the experiment does not succeed, the
conclusion that this is due to the fact that the circuits are now not
tuned, would be far from being safe. For the two circuits act as
condenser coatings and the addition of the coil to one of them is
equivalent to bridging them, at the point where the coil is placed, by a
small condenser, and the effect of the latter might be to prevent the
spark from jumping through the discharge space by diminishing the
alternating E. M. F. acting across the same. All these remarks, and many
more which might be added but for fear of wandering too far from the
subject, are made with the pardonable intention of cautioning the
unsuspecting student, who might gain an entirely unwarranted opinion of
his skill at seeing every experiment succeed; but they are in no way
thrust upon the experienced as novel observations.

In order to make reliable observations of electric resonance effects it
is very desirable, if not necessary, to employ an alternator giving
currents which rise and fall harmonically, as in working with make and
break currents the observations are not always trustworthy, since many
phenomena, which depend on the rate of change, may be produced with
widely different frequencies. Even when making such observations with an
alternator one is apt to be mistaken. When a circuit is connected to an
alternator there are an indefinite number of values for capacity and
self-induction which, in conjunction, will satisfy the condition of
resonance. So there are in mechanics an infinite number of tuning forks
which will respond to a note of a certain pitch, or loaded springs which
have a definite period of vibration. But the resonance will be most
perfectly attained in that case in which the motion is effected with the
greatest freedom. Now in mechanics, considering the vibration in the
common medium--that is, air--it is of comparatively little importance
whether one tuning fork be somewhat larger than another, because the
losses in the air are not very considerable. One may, of course, enclose
a tuning fork in an exhausted vessel and by thus reducing the air
resistance to a minimum obtain better resonant action. Still the
difference would not be very great. But it would make a great difference
if the tuning fork were immersed in mercury. In the electrical vibration
it is of enormous importance to arrange the conditions so that the
vibration is effected with the greatest freedom. The magnitude of the
resonance effect depends, under otherwise equal conditions, on the
quantity of electricity set in motion or on the strength of the current
driven through the circuit. But the circuit opposes the passage of the
currents by reason of its impedance and therefore, to secure the best
action it is necessary to reduce the impedance to a minimum. It is
impossible to overcome it entirely, but merely in part, for the ohmic
resistance cannot be overcome. But when the frequency of the impulses is
very great, the flow of the current is practically determined by
self-induction. Now self-induction can be overcome by combining it with
capacity. If the relation between these is such, that at the frequency
used they annul each other, that is, have such values as to satisfy the
condition of resonance, and the greatest quantity of electricity is made
to flow through the external circuit, then the best result is obtained.
It is simpler and safer to join the condenser in series with the
self-induction. It is clear that in such combinations there will be,
for a given frequency, and considering only the fundamental vibration,
values which will give the best result, with the condenser in shunt to
the self-induction coil; of course more such values than with the
condenser in series. But practical conditions determine the selection.
In the latter case in performing the experiments one may take a small
self-induction and a large capacity or a small capacity and a large
self-induction, but the latter is preferable, because it is inconvenient
to adjust a large capacity by small steps. By taking a coil with a very
large self-induction the critical capacity is reduced to a very small
value, and the capacity of the coil itself may be sufficient. It is
easy, especially by observing certain artifices, to wind a coil through
which the impedance will be reduced to the value of the ohmic resistance
only; and for any coil there is, of course, a frequency at which the
maximum current will be made to pass through the coil. The observation
of the relation between self-induction, capacity and frequency is
becoming important in the operation of alternate current apparatus, such
as transformers or motors, because by a judicious determination of the
elements the employment of an expensive condenser becomes unnecessary.
Thus it is possible to pass through the coils of an alternating current
motor under the normal working conditions the required current with a
low E. M. F. and do away entirely with the false current, and the larger
the motor, the easier such a plan becomes practicable; but it is
necessary for this to employ currents of very high potential or high
frequency.

[Illustration: FIG. 184.]

In Fig. 184 I. is shown a plan which has been followed in the study of
the resonance effects by means of a high frequency alternator. C_{1} is
a coil of many turns, which is divided into small separate sections for
the purpose of adjustment. The final adjustment was made sometimes with
a few thin iron wires (though this is not always advisable) or with a
closed secondary. The coil C_{1} is connected with one of its ends to
the line L from the alternator G and with the other end to one of the
plates _c_ of a condenser c c_{1}, the plate (c_{1}) of the latter
being connected to a much larger plate P_{1}. In this manner both
capacity and self-induction were adjusted to suit the dynamo frequency.

As regards the rise of potential through resonant action, of course,
theoretically, it may amount to anything since it depends on
self-induction and resistance and since these may have any value. But in
practice one is limited in the selection of these values and besides
these, there are other limiting causes. One may start with, say, 1,000
volts and raise the E. M. F. to 50 times that value, but one cannot
start with 100,000 and raise it to ten times that value because of the
losses in the media which are great, especially if the frequency is
high. It should be possible to start with, for instance, two volts from
a high or low frequency circuit of a dynamo and raise the E. M. F. to
many hundred times that value. Thus coils of the proper dimensions might
be connected each with only one of its ends to the mains from a machine
of low E. M. F., and though the circuit of the machine would not be
closed in the ordinary acceptance of the term, yet the machine might be
burned out if a proper resonance effect would be obtained. I have not
been able to produce, nor have I observed with currents from a dynamo
machine, such great rises of potential. It is possible, if not probable,
that with currents obtained from apparatus containing iron the
disturbing influence of the latter is the cause that these theoretical
possibilities cannot be realized. But if such is the case I attribute it
solely to the hysteresis and Foucault current losses in the core.
Generally it was necessary to transform upward, when the E. M. F. was
very low, and usually an ordinary form of induction coil was employed,
but sometimes the arrangement illustrated in Fig. 184 II., has been
found to be convenient. In this case a coil C is made in a great many
sections, a few of these being used as a primary. In this manner both
primary and secondary are adjustable. One end of the coil is connected
to the line L_{1} from the alternator, and the other line L is connected
to the intermediate point of the coil. Such a coil with adjustable
primary and secondary will be found also convenient in experiments with
the disruptive discharge. When true resonance is obtained the top of the
wave must of course be on the free end of the coil as, for instance, at
the terminal of the phosphorescence bulb B. This is easily recognized
by observing the potential of a point on the wire _w_ near to the coil.

In connection with resonance effects and the problem of transmission of
energy over a single conductor which was previously considered, I would
say a few words on a subject which constantly fills my thoughts and
which concerns the welfare of all. I mean the transmission of
intelligible signals or perhaps even power to any distance without the
use of wires. I am becoming daily more convinced of the practicability
of the scheme; and though I know full well that the great majority of
scientific men will not believe that such results can be practically and
immediately realized, yet I think that all consider the developments in
recent years by a number of workers to have been such as to encourage
thought and experiment in this direction. My conviction has grown so
strong, that I no longer look upon this plan of energy or intelligence
transmission as a mere theoretical possibility, but as a serious problem
in electrical engineering, which must be carried out some day. The idea
of transmitting intelligence without wires is the natural outcome of the
most recent results of electrical investigations. Some enthusiasts have
expressed their belief that telephony to any distance by induction
through the air is possible. I cannot stretch my imagination so far, but
I do firmly believe that it is practicable to disturb by means of
powerful machines the electrostatic condition of the earth and thus
transmit intelligible signals and perhaps power. In fact, what is there
against the carrying out of such a scheme? We now know that electric
vibration may be transmitted through a single conductor. Why then not
try to avail ourselves of the earth for this purpose? We need not be
frightened by the idea of distance. To the weary wanderer counting the
mile-posts the earth may appear very large, but to that happiest of all
men, the astronomer, who gazes at the heavens and by their standard
judges the magnitude of our globe, it appears very small. And so I think
it must seem to the electrician, for when he considers the speed with
which an electric disturbance is propagated through the earth all his
ideas of distance must completely vanish.

A point of great importance would be first to know what is the capacity
of the earth? and what charge does it contain if electrified? Though we
have no positive evidence of a charged body existing in space without
other oppositely electrified bodies being near, there is a fair
probability that the earth is such a body, for by whatever process it
was separated from other bodies--and this is the accepted view of its
origin--it must have retained a charge, as occurs in all processes of
mechanical separation. If it be a charged body insulated in space its
capacity should be extremely small, less than one-thousandth of a farad.
But the upper strata of the air are conducting, and so, perhaps, is the
medium in free space beyond the atmosphere, and these may contain an
opposite charge. Then the capacity might be incomparably greater. In any
case it is of the greatest importance to get an idea of what quantity of
electricity the earth contains. It is difficult to say whether we shall
ever acquire this necessary knowledge, but there is hope that we may,
and that is, by means of electrical resonance. If ever we can ascertain
at what period the earth's charge, when disturbed, oscillates with
respect to an oppositely electrified system or known circuit, we shall
know a fact possibly of the greatest importance to the welfare of the
human race. I propose to seek for the period by means of an electrical
oscillator, or a source of alternating electric currents. One of the
terminals of the source would be connected to earth as, for instance, to
the city water mains, the other to an insulated body of large surface.
It is possible that the outer conducting air strata, or free space,
contain an opposite charge and that, together with the earth, they form
a condenser of very large capacity. In such case the period of vibration
may be very low and an alternating dynamo machine might serve for the
purpose of the experiment. I would then transform the current to a
potential as high as it would be found possible and connect the ends of
the high tension secondary to the ground and to the insulated body. By
varying the frequency of the currents and carefully observing the
potential of the insulated body and watching for the disturbance at
various neighboring points of the earth's surface resonance might be
detected. Should, as the majority of scientific men in all probability
believe, the period be extremely small, then a dynamo machine would not
do and a proper electrical oscillator would have to be produced and
perhaps it might not be possible to obtain such rapid vibrations. But
whether this be possible or not, and whether the earth contains a charge
or not, and whatever may be its period of vibration, it certainly is
possible--for of this we have daily evidence--to produce some electrical
disturbance sufficiently powerful to be perceptible by suitable
instruments at any point of the earth's surface.

[Illustration: FIG. 185.]

Assume that a source of alternating current S be connected, as in Fig.
185, with one of its terminals to earth (conveniently to the water
mains) and with the other to a body of large surface P. When the
electric oscillation is set up there will be a movement of electricity
in and out of P, and alternating currents will pass through the earth,
converging to, or diverging from, the point C where the ground
connection is made. In this manner neighboring points on the earth's
surface within a certain radius will be disturbed. But the disturbance
will diminish with the distance, and the distance at which the effect
will still be perceptible will depend on the quantity of electricity set
in motion. Since the body P is insulated, in order to displace a
considerable quantity, the potential of the source must be excessive,
since there would be limitations as to the surface of P. The conditions
might be adjusted so that the generator or source S will set up the same
electrical movement as though its circuit were closed. Thus it is
certainly practicable to impress an electric vibration at least of a
certain low period upon the earth by means of proper machinery. At what
distance such a vibration might be made perceptible can only be
conjectured. I have on another occasion considered the question how the
earth might behave to electric disturbances. There is no doubt that,
since in such an experiment the electrical density at the surface could
be but extremely small considering the size of the earth, the air would
not act as a very disturbing factor, and there would be not much energy
lost through the action of the air, which would be the case if the
density were great. Theoretically, then, it could not require a great
amount of energy to produce a disturbance perceptible at great distance,
or even all over the surface of the globe. Now, it is quite certain that
at any point within a certain radius of the source S a properly adjusted
self-induction and capacity device can be set in action by resonance.
But not only can this be done, but another source S_{1}, Fig. 185,
similar to S, or any number of such sources, can be set to work in
synchronism with the latter, and the vibration thus intensified and
spread over a large area, or a flow of electricity produced to or from
the source S_{1} if the same be of opposite phase to the source S. I
think that beyond doubt it is possible to operate electrical devices in
a city through the ground or pipe system by resonance from an electrical
oscillator located at a central point. But the practical solution of
this problem would be of incomparably smaller benefit to man than the
realization of the scheme of transmitting intelligence, or perhaps
power, to any distance through the earth or environing medium. If this
is at all possible, distance does not mean anything. Proper apparatus
must first be produced by means of which the problem can be attacked and
I have devoted much thought to this subject. I am firmly convinced that
it can be done and hope that we shall live to see it done.


ON THE LIGHT PHENOMENA PRODUCED BY HIGH-FREQUENCY CURRENTS OF HIGH
POTENTIAL AND GENERAL REMARKS RELATING TO THE SUBJECT.

Returning now to the light effects which it has been the chief object to
investigate, it is thought proper to divide these effects into four
classes: 1. Incandescence of a solid. 2. Phosphorescence. 3.
Incandescence or phosphorescence of a rarefied gas; and 4. Luminosity
produced in a gas at ordinary pressure. The first question is: How are
these luminous effects produced? In order to answer this question as
satisfactorily as I am able to do in the light of accepted views and
with the experience acquired, and to add some interest to this
demonstration, I shall dwell here upon a feature which I consider of
great importance, inasmuch as it promises, besides, to throw a better
light upon the nature of most of the phenomena produced by
high-frequency electric currents. I have on other occasions pointed out
the great importance of the presence of the rarefied gas, or atomic
medium in general, around the conductor through which alternate currents
of high frequency are passed, as regards the heating of the conductor by
the currents. My experiments, described some time ago, have shown that,
the higher the frequency and potential difference of the currents, the
more important becomes the rarefied gas in which the conductor is
immersed, as a factor of the heating. The potential difference, however,
is, as I then pointed out, a more important element than the frequency.
When both of these are sufficiently high, the heating may be almost
entirely due to the presence of the rarefied gas. The experiments to
follow will show the importance of the rarefied gas, or, generally, of
gas at ordinary or other pressure as regards the incandescence or other
luminous effects produced by currents of this kind.

I take two ordinary 50-volt 16 C. P. lamps which are in every respect
alike, with the exception, that one has been opened at the top and the
air has filled the bulb, while the other is at the ordinary degree of
exhaustion of commercial lamps. When I attach the lamp which is
exhausted to the terminal of the secondary of the coil, which I have
already used, as in experiments illustrated in Fig. 179_a_ for instance,
and turn on the current, the filament, as you have before seen, comes to
high incandescence. When I attach the second lamp, which is filled with
air, instead of the former, the filament still glows, but much less
brightly. This experiment illustrates only in part the truth of the
statements before made. The importance of the filament's being immersed
in rarefied gas is plainly noticeable but not to such a degree as might
be desirable. The reason is that the secondary of this coil is wound for
low tension, having only 150 turns, and the potential difference at the
terminals of the lamp is therefore small. Were I to take another coil
with many more turns in the secondary, the effect would be increased,
since it depends partially on the potential difference, as before
remarked. But since the effect likewise depends on the frequency, it
maybe properly stated that it depends on the time rate of the variation
of the potential difference. The greater this variation, the more
important becomes the gas as an element of heating. I can produce a much
greater rate of variation in another way, which, besides, has the
advantage of doing away with the objections, which might be made in the
experiment just shown, even if both the lamps were connected in series
or multiple arc to the coil, namely, that in consequence of the
reactions existing between the primary and secondary coil the
conclusions are rendered uncertain. This result I secure by charging,
from an ordinary transformer which is fed from the alternating current
supply station, a battery of condensers, and discharging the latter
directly through a circuit of small self-induction, as before
illustrated in Figs. 183_a_, 183_b_, and 183_c_.

[Illustration: FIG. 186a.]

[Illustration: FIG. 186b.]

[Illustration: FIG. 186c.]

In Figs. 186_a_, 186_b_ and 186_c_, the heavy copper bars B B_{1}, are
connected to the opposite coatings of a battery of condensers, or
generally in such way, that the high frequency or sudden discharges are
made to traverse them. I connect first an ordinary 50-volt incandescent
lamp to the bars by means of the clamps _c c_. The discharges being
passed through the lamp, the filament is rendered incandescent, though
the current through it is very small, and would not be nearly sufficient
to produce a visible effect under the conditions of ordinary use of the
lamp. Instead of this I now attach to the bars another lamp exactly like
the first, but with the seal broken off, the bulb being therefore filled
with air at ordinary pressure. When the discharges are directed through
the filament, as before, it does not become incandescent. But the result
might still be attributed to one of the many possible reactions. I
therefore connect both the lamps in multiple arc as illustrated in Fig.
186_a_. Passing the discharges through both the lamps, again the
filament in the exhausted lamp _l_ glows very brightly while that in the
non-exhausted lamp l_{1} remains dark, as previously. But it should
not be thought that the latter lamp is taking only a small fraction of
the energy supplied to both the lamps; on the contrary, it may consume a
considerable portion of the energy and it may become even hotter than
the one which burns brightly. In this experiment the potential
difference at the terminals of the lamps varies in sign theoretically
three to four million times a second. The ends of the filaments are
correspondingly electrified, and the gas in the bulbs is violently
agitated and a large portion of the supplied energy is thus converted
into heat. In the non-exhausted bulb, there being a few million times
more gas molecules than in the exhausted one, the bombardment, which is
most violent at the ends of the filament, in the neck of the bulb,
consumes a large portion of the energy without producing any visible
effect. The reason is that, there being many molecules, the bombardment
is quantitatively considerable, but the individual impacts are not very
violent, as the speeds of the molecules are comparatively small owing to
the small free path. In the exhausted bulb, on the contrary, the speeds
are very great, and the individual impacts are violent and therefore
better adapted to produce a visible effect. Besides, the convection of
heat is greater in the former bulb. In both the bulbs the current
traversing the filaments is very small, incomparably smaller than that
which they require on an ordinary low-frequency circuit. The potential
difference, however, at the ends of the filaments is very great and
might be possibly 20,000 volts or more, if the filaments were straight
and their ends far apart. In the ordinary lamp a spark generally occurs
between the ends of the filament or between the platinum wires outside,
before such a difference of potential can be reached.

It might be objected that in the experiment before shown the lamps,
being in multiple arc, the exhausted lamp might take a much larger
current and that the effect observed might not be exactly attributable
to the action of the gas in the bulbs. Such objections will lose much
weight if I connect the lamps in series, with the same result. When this
is done and the discharges are directed through the filaments, it is
again noted that the filament in the non-exhausted bulb l_{1}, remains
dark, while that in the exhausted one (_l_) glows even more intensely
than under its normal conditions of working, Fig. 186_b_. According to
general ideas the current through the filaments should now be the same,
were it not modified by the presence of the gas around the filaments.

At this juncture I may point out another interesting feature, which
illustrates the effect of the rate of change of potential of the
currents. I will leave the two lamps connected in series to the bars
B B_{1}, as in the previous experiment, Fig. 186_b_, but will presently
reduce considerably the frequency of the currents, which was excessive
in the experiment just before shown. This I may do by inserting a
self-induction coil in the path of the discharges, or by augmenting the
capacity of the condensers. When I now pass these low-frequency
discharges through the lamps, the exhausted lamp _l_ again is as bright
as before, but it is noted also that the non-exhausted lamp l_{1}
glows, though not quite as intensely as the other. Reducing the current
through the lamps, I may bring the filament in the latter lamp to
redness, and, though the filament in the exhausted lamp _l_ is bright,
Fig. 186_c_, the degree of its incandescence is much smaller than in
Fig. 186_b_, when the currents were of a much higher frequency.

In these experiments the gas acts in two opposite ways in determining
the degree of the incandescence of the filaments, that is, by convection
and bombardment. The higher the frequency and potential of the currents,
the more important becomes the bombardment. The convection on the
contrary should be the smaller, the higher the frequency. When the
currents are steady there is practically no bombardment, and convection
may therefore with such currents also considerably modify the degree of
incandescence and produce results similar to those just before shown.
Thus, if two lamps exactly alike, one exhausted and one not exhausted,
are connected in multiple arc or series to a direct-current machine, the
filament in the non-exhausted lamp will require a considerably greater
current to be rendered incandescent. This result is entirely due to
convection, and the effect is the more prominent the thinner the
filament. Professor Ayrton and Mr. Kilgour some time ago published
quantitative results concerning the thermal emissivity by radiation and
convection in which the effect with thin wires was clearly shown. This
effect may be strikingly illustrated by preparing a number of small,
short, glass tubes, each containing through its axis the thinnest
obtainable platinum wire. If these tubes be highly exhausted, a number
of them may be connected in multiple arc to a direct-current machine and
all of the wires may be kept at incandescence with a smaller current
than that required to render incandescent a single one of the wires if
the tube be not exhausted. Could the tubes be so highly exhausted that
convection would be nil, then the relative amounts of heat given off by
convection and radiation could be determined without the difficulties
attending thermal quantitative measurements. If a source of electric
impulses of high frequency and very high potential is employed, a still
greater number of the tubes may be taken and the wires rendered
incandescent by a current not capable of warming perceptibly a wire of
the same size immersed in air at ordinary pressure, and conveying the
energy to all of them.

I may here describe a result which is still more interesting, and to
which I have been led by the observation of these phenomena. I noted
that small differences in the density of the air produced a considerable
difference in the degree of incandescence of the wires, and I thought
that, since in a tube, through which a luminous discharge is passed, the
gas is generally not of uniform density, a very thin wire contained in
the tube might be rendered incandescent at certain places of smaller
density of the gas, while it would remain dark at the places of greater
density, where the convection would be greater and the bombardment less
intense. Accordingly a tube _t_ was prepared, as illustrated in Fig.
187, which contained through the middle a very fine platinum wire _w_.
The tube was exhausted to a moderate degree and it was found that when
it was attached to the terminal of a high-frequency coil the platinum
wire _w_ would indeed, become incandescent in patches, as illustrated in
Fig. 187. Later a number of these tubes with one or more wires were
prepared, each showing this result. The effect was best noted when the
striated discharge occurred in the tube, but was also produced when the
striae were not visible, showing that, even then, the gas in the tube was
not of uniform density. The position of the striae was generally such,
that the rarefactions corresponded to the places of incandescence or
greater brightness on the wire _w_. But in a few instances it was noted,
that the bright spots on the wire were covered by the dense parts of the
striated discharge as indicated by _l_ in Fig. 187, though the effect
was barely perceptible. This was explained in a plausible way by
assuming that the convection was not widely different in the dense and
rarefied places, and that the bombardment was greater on the dense
places of the striated discharge. It is, in fact, often observed in
bulbs, that under certain conditions a thin wire is brought to higher
incandescence when the air is not too highly rarefied. This is the case
when the potential of the coil is not high enough for the vacuum, but
the result may be attributed to many different causes. In all cases this
curious phenomenon of incandescence disappears when the tube, or rather
the wire, acquires throughout a uniform temperature.

[Illustration: FIG. 187.]

[Illustration: FIG. 188.]

Disregarding now the modifying effect of convection there are then two
distinct causes which determine the incandescence of a wire or filament
with varying currents, that is, conduction current and bombardment. With
steady currents we have to deal only with the former of these two
causes, and the heating effect is a minimum, since the resistance is
least to steady flow. When the current is a varying one the resistance
is greater, and hence the heating effect is increased. Thus if the rate
of change of the current is very great, the resistance may increase to
such an extent that the filament is brought to incandescence with
inappreciable currents, and we are able to take a short and thick block
of carbon or other material and bring it to bright incandescence with a
current incomparably smaller than that required to bring to the same
degree of incandescence an ordinary thin lamp filament with a steady or
low frequency current. This result is important, and illustrates how
rapidly our views on these subjects are changing, and how quickly our
field of knowledge is extending. In the art of incandescent lighting, to
view this result in one aspect only, it has been commonly considered as
an essential requirement for practical success, that the lamp filament
should be thin and of high resistance. But now we know that the
resistance of the filament to the steady flow does not mean anything;
the filament might as well be short and thick; for if it be immersed in
rarefied gas it will become incandescent by the passage of a small
current. It all depends on the frequency and potential of the currents.
We may conclude from this, that it would be of advantage, so far as the
lamp is considered, to employ high frequencies for lighting, as they
allow the use of short and thick filaments and smaller currents.

If a wire or filament be immersed in a homogeneous medium, all the
heating is due to true conduction current, but if it be enclosed in an
exhausted vessel the conditions are entirely different. Here the gas
begins to act and the heating effect of the conduction current, as is
shown in many experiments, may be very small compared with that of the
bombardment. This is especially the case if the circuit is not closed
and the potentials are of course very high. Suppose that a fine filament
enclosed in an exhausted vessel be connected with one of its ends to the
terminal of a high tension coil and with its other end to a large
insulated plate. Though the circuit is not closed, the filament, as I
have before shown, is brought to incandescence. If the frequency and
potential be comparatively low, the filament is heated by the current
passing _through it_. If the frequency and potential, and principally
the latter, be increased, the insulated plate need be but very small, or
may be done away with entirely; still the filament will become
incandescent, practically all the heating being then due to the
bombardment. A practical way of combining both the effects of conduction
currents and bombardment is illustrated in Fig. 188, in which an
ordinary lamp is shown provided with a very thin filament which has one
of the ends of the latter connected to a shade serving the purpose of
the insulated plate, and the other end to the terminal of a high tension
source. It should not be thought that only rarefied gas is an important
factor in the heating of a conductor by varying currents, but gas at
ordinary pressure may become important, if the potential difference and
frequency of the currents is excessive. On this subject I have already
stated, that when a conductor is fused by a stroke of lightning, the
current through it may be exceedingly small, not even sufficient to heat
the conductor perceptibly, were the latter immersed in a homogeneous
medium.

From the preceding it is clear that when a conductor of high resistance
is connected to the terminals of a source of high frequency currents of
high potential, there may occur considerable dissipation of energy,
principally at the ends of the conductor, in consequence of the action
of the gas surrounding the conductor. Owing to this, the current through
a section of the conductor at a point midway between its ends may be
much smaller than through a section near the ends. Furthermore, the
current passes principally through the outer portions of the conductor,
but this effect is to be distinguished from the skin effect as
ordinarily interpreted, for the latter would, or should, occur also in a
continuous incompressible medium. If a great many incandescent lamps are
connected in series to a source of such currents, the lamps at the ends
may burn brightly, whereas those in the middle may remain entirely dark.
This is due principally to bombardment, as before stated. But even if
the currents be steady, provided the difference of potential is very
great, the lamps at the end will burn more brightly than those in the
middle. In such case there is no rhythmical bombardment, and the result
is produced entirely by leakage. This leakage or dissipation into space
when the tension is high, is considerable when incandescent lamps are
used, and still more considerable with arcs, for the latter act like
flames. Generally, of course, the dissipation is much smaller with
steady, than with varying, currents.

I have contrived an experiment which illustrates in an interesting
manner the effect of lateral diffusion. If a very long tube is attached
to the terminal of a high frequency coil, the luminosity is greatest
near the terminal and falls off gradually towards the remote end. This
is more marked if the tube is narrow.

A small tube about one-half inch in diameter and twelve inches long
(Fig. 189), has one of its ends drawn out into a fine fibre _f_ nearly
three feet long. The tube is placed in a brass socket T which can be
screwed on the terminal T_{1} of the induction coil. The discharge
passing through the tube first illuminates the bottom of the same, which
is of comparatively large section; but through the long glass fibre the
discharge cannot pass. But gradually the rarefied gas inside becomes
warmed and more conducting and the discharge spreads into the glass
fibre. This spreading is so slow, that it may take half a minute or more
until the discharge has worked through up to the top of the glass fibre,
then presenting the appearance of a strongly luminous thin thread. By
adjusting the potential at the terminal the light may be made to travel
upwards at any speed. Once, however, the glass fibre is heated, the
discharge breaks through its entire length instantly. The interesting
point to be noted is that, the higher the frequency of the currents, or
in other words, the greater relatively the lateral dissipation, at a
slower rate may the light be made to propagate through the fibre. This
experiment is best performed with a highly exhausted and freshly made
tube. When the tube has been used for some time the experiment often
fails. It is possible that the gradual and slow impairment of the vacuum
is the cause. This slow propagation of the discharge through a very
narrow glass tube corresponds exactly to the propagation of heat through
a bar warmed at one end. The quicker the heat is carried away laterally
the longer time it will take for the heat to warm the remote end. When
the current of a low frequency coil is passed through the fibre from end
to end, then the lateral dissipation is small and the discharge
instantly breaks through almost without exception.

[Illustration: FIG. 189.]

[Illustration: FIG. 190.]

After these experiments and observations which have shown the importance
of the discontinuity or atomic structure of the medium and which will
serve to explain, in a measure at least, the nature of the four kinds of
light effects producible with these currents, I may now give you an
illustration of these effects. For the sake of interest I may do this in
a manner which to many of you might be novel. You have seen before that
we may now convey the electric vibration to a body by means of a single
wire or conductor of any kind. Since the human frame is conducting I
may convey the vibration through my body.

First, as in some previous experiments, I connect my body with one of
the terminals of a high-tension transformer and take in my hand an
exhausted bulb which contains a small carbon button mounted upon a
platinum wire leading to the outside of the bulb, and the button is
rendered incandescent as soon as the transformer is set to work (Fig.
190). I may place a conducting shade on the bulb which serves to
intensify the action, but is not necessary. Nor is it required that the
button should be in conducting connection with the hand through a wire
leading through the glass, for sufficient energy may be transmitted
through the glass itself by inductive action to render the button
incandescent.

[Illustration: FIG. 191.]

[Illustration: FIG. 192.]

Next I take a highly exhausted bulb containing a strongly phosphorescent
body, above which is mounted a small plate of aluminum on a platinum
wire leading to the outside, and the currents flowing through my body
excite intense phosphorescence in the bulb (Fig. 191). Next again I take
in my hand a simple exhausted tube, and in the same manner the gas
inside the tube is rendered highly incandescent or phosphorescent (Fig.
192). Finally, I may take in my hand a wire, bare or covered with thick
insulation, it is quite immaterial; the electrical vibration is so
intense as to cover the wire with a luminous film (Fig. 193).

[Illustration: FIG. 193.]

[Illustration: FIG. 194.]

[Illustration: FIG. 195.]

A few words must now be devoted to each of these phenomena. In the first
place, I will consider the incandescence of a button or of a solid in
general, and dwell upon some facts which apply equally to all these
phenomena. It was pointed out before that when a thin conductor, such as
a lamp filament, for instance, is connected with one of its ends to the
terminal of a transformer of high tension the filament is brought to
incandescence partly by a conduction current and partly by bombardment.
The shorter and thicker the filament the more important becomes the
latter, and finally, reducing the filament to a mere button, all the
heating must practically be attributed to the bombardment. So in the
experiment before shown, the button is rendered incandescent by the
rhythmical impact of freely movable small bodies in the bulb. These
bodies may be the molecules of the residual gas, particles of dust or
lumps torn from the electrode; whatever they are, it is certain that the
heating of the button is essentially connected with the pressure of such
freely movable particles, or of atomic matter in general in the bulb.
The heating is the more intense the greater the number of impacts per
second and the greater the energy of each impact. Yet the button would
be heated also if it were connected to a source of a steady potential.
In such a case electricity would be carried away from the button by the
freely movable carriers or particles flying about, and the quantity of
electricity thus carried away might be sufficient to bring the button to
incandescence by its passage through the latter. But the bombardment
could not be of great importance in such case. For this reason it would
require a comparatively very great supply of energy to the button to
maintain it at incandescence with a steady potential. The higher the
frequency of the electric impulses the more economically can the button
be maintained at incandescence. One of the chief reasons why this is so,
is, I believe, that with impulses of very high frequency there is less
exchange of the freely movable carriers around the electrode and this
means, that in the bulb the heated matter is better confined to the
neighborhood of the button. If a double bulb, as illustrated in Fig. 194
be made, comprising a large globe B and a small one _b_, each containing
as usual a filament _f_ mounted on a platinum wire w and w_{1}, it
is found, that if the filaments _f f_ be exactly alike, it requires less
energy to keep the filament in the globe _b_ at a certain degree of
incandescence, than that in the globe B. This is due to the confinement
of the movable particles around the button. In this case it is also
ascertained, that the filament in the small globe _b_ is less
deteriorated when maintained a certain length of time at incandescence.
This is a necessary consequence of the fact that the gas in the small
bulb becomes strongly heated and therefore a very good conductor, and
less work is then performed on the button, since the bombardment becomes
less intense as the conductivity of the gas increases. In this
construction, of course, the small bulb becomes very hot and when it
reaches an elevated temperature the convection and radiation on the
outside increase. On another occasion I have shown bulbs in which this
drawback was largely avoided. In these instances a very small bulb,
containing a refractory button, was mounted in a large globe and the
space between the walls of both was highly exhausted. The outer large
globe remained comparatively cool in such constructions. When the large
globe was on the pump and the vacuum between the walls maintained
permanent by the continuous action of the pump, the outer globe would
remain quite cold, while the button in the small bulb was kept at
incandescence. But when the seal was made, and the button in the small
bulb maintained incandescent some length of time, the large globe too
would become warmed. From this I conjecture that if vacuous space (as
Prof. Dewar finds) cannot convey heat, it is so merely in virtue of our
rapid motion through space or, generally speaking, by the motion of the
medium relatively to us, for a permanent condition could not be
maintained without the medium being constantly renewed. A vacuum cannot,
according to all evidence, be permanently maintained around a hot body.

In these constructions, before mentioned, the small bulb inside would,
at least in the first stages, prevent all bombardment against the outer
large globe. It occurred to me then to ascertain how a metal sieve would
behave in this respect, and several bulbs, as illustrated in Fig. 195,
were prepared for this purpose. In a globe _b_, was mounted a thin
filament _f_ (or button) upon a platinum wire _w_ passing through a
glass stem and leading to the outside of the globe. The filament _f_ was
surrounded by a metal sieve _s_. It was found in experiments with such
bulbs that a sieve with wide meshes apparently did not in the slightest
affect the bombardment against the globe _b_. When the vacuum was high,
the shadow of the sieve was clearly projected against the globe and the
latter would get hot in a short while. In some bulbs the sieve _s_ was
connected to a platinum wire sealed in the glass. When this wire was
connected to the other terminal of the induction coil (the E. M. F.
being kept low in this case), or to an insulated plate, the bombardment
against the outer globe _b_ was diminished. By taking a sieve with fine
meshes the bombardment against the globe _b_ was always diminished, but
even then if the exhaustion was carried very far, and when the potential
of the transformer was very high, the globe _b_ would be bombarded and
heated quickly, though no shadow of the sieve was visible, owing to the
smallness of the meshes. But a glass tube or other continuous body
mounted so as to surround the filament, did entirely cut off the
bombardment and for a while the outer globe _b_ would remain perfectly
cold. Of course when the glass tube was sufficiently heated the
bombardment against the outer globe could be noted at once. The
experiments with these bulbs seemed to show that the speeds of the
projected molecules or particles must be considerable (though quite
insignificant when compared with that of light), otherwise it would be
difficult to understand how they could traverse a fine metal sieve
without being affected, unless it were found that such small particles
or atoms cannot be acted upon directly at measurable distances. In
regard to the speed of the projected atoms, Lord Kelvin has recently
estimated it at about one kilometre a second or thereabouts in an
ordinary Crookes bulb. As the potentials obtainable with a disruptive
discharge coil are much higher than with ordinary coils, the speeds
must, of course, be much greater when the bulbs are lighted from such a
coil. Assuming the speed to be as high as five kilometres and uniform
through the whole trajectory, as it should be in a very highly exhausted
vessel, then if the alternate electrifications of the electrode would be
of a frequency of five million, the greatest distance a particle could
get away from the electrode would be one millimetre, and if it could be
acted upon directly at that distance, the exchange of electrode matter
or of the atoms would be very slow and there would be practically no
bombardment against the bulb. This at least should be so, if the action
of an electrode upon the atoms of the residual gas would be such as upon
electrified bodies which we can perceive. A hot body enclosed in an
exhausted bulb produces always atomic bombardment, but a hot body has no
definite rhythm, for its molecules perform vibrations of all kinds.

If a bulb containing a button or filament be exhausted as high as is
possible with the greatest care and by the use of the best artifices, it
is often observed that the discharge cannot, at first, break through,
but after some time, probably in consequence of some changes within the
bulb, the discharge finally passes through and the button is rendered
incandescent. In fact, it appears that the higher the degree of
exhaustion the easier is the incandescence produced. There seem to be no
other causes to which the incandescence might be attributed in such case
except to the bombardment or similar action of the residual gas, or of
particles of matter in general. But if the bulb be exhausted with the
greatest care can these play an important part? Assume the vacuum in the
bulb to be tolerably perfect, the great interest then centres in the
question: Is the medium which pervades all space continuous or atomic?
If atomic, then the heating of a conducting button or filament in an
exhausted vessel might be due largely to ether bombardment, and then the
heating of a conductor in general through which currents of high
frequency or high potential are passed must be modified by the behavior
of such medium; then also the skin effect, the apparent increase of the
ohmic resistance, etc., admit, partially at least, of a different
explanation.

It is certainly more in accordance with many phenomena observed with
high-frequency currents to hold that all space is pervaded with free
atoms, rather than to assume that it is devoid of these, and dark and
cold, for so it must be, if filled with a continuous medium, since in
such there can be neither heat nor light. Is then energy transmitted by
independent carriers or by the vibration of a continuous medium? This
important question is by no means as yet positively answered. But most
of the effects which are here considered, especially the light effects,
incandescence, or phosphorescence, involve the presence of free atoms
and would be impossible without these.

In regard to the incandescence of a refractory button (or filament) in
an exhausted receiver, which has been one of the subjects of this
investigation, the chief experiences, which may serve as a guide in
constructing such bulbs, may be summed up as follows: 1. The button
should be as small as possible, spherical, of a smooth or polished
surface, and of refractory material which withstands evaporation best.
2. The support of the button should be very thin and screened by an
aluminum and mica sheet, as I have described on another occasion. 3. The
exhaustion of the bulb should be as high as possible. 4. The frequency
of the currents should be as high as practicable. 5. The currents should
be of a harmonic rise and fall, without sudden interruptions. 6. The
heat should be confined to the button by inclosing the same in a small
bulb or otherwise. 7. The space between the walls of the small bulb and
the outer globe should be highly exhausted.

Most of the considerations which apply to the incandescence of a solid
just considered may likewise be applied to phosphorescence. Indeed, in
an exhausted vessel the phosphorescence is, as a rule, primarily excited
by the powerful beating of the electrode stream of atoms against the
phosphorescent body. Even in many cases, where there is no evidence of
such a bombardment, I think that phosphorescence is excited by violent
impacts of atoms, which are not necessarily thrown off from the
electrode but are acted upon from the same inductively through the
medium or through chains of other atoms. That mechanical shocks play an
important part in exciting phosphorescence in a bulb may be seen from
the following experiment. If a bulb, constructed as that illustrated in
Fig. 174, be taken and exhausted with the greatest care so that the
discharge cannot pass, the filament _f_ acts by electrostatic induction
upon the tube _t_ and the latter is set in vibration. If the tube _o_ be
rather wide, about an inch or so, the filament may be so powerfully
vibrated that whenever it hits the glass tube it excites
phosphorescence. But the phosphorescence ceases when the filament comes
to rest. The vibration can be arrested and again started by varying the
frequency of the currents. Now the filament has its own period of
vibration, and if the frequency of the currents is such that there is
resonance, it is easily set vibrating, though the potential of the
currents be small. I have often observed that the filament in the bulb
is destroyed by such mechanical resonance. The filament vibrates as a
rule so rapidly that it cannot be seen and the experimenter may at first
be mystified. When such an experiment as the one described is carefully
performed, the potential of the currents need be extremely small, and
for this reason I infer that the phosphorescence is then due to the
mechanical shock of the filament against the glass, just as it is
produced by striking a loaf of sugar with a knife. The mechanical shock
produced by the projected atoms is easily noted when a bulb containing a
button is grasped in the hand and the current turned on suddenly. I
believe that a bulb could be shattered by observing the conditions of
resonance.

In the experiment before cited it is, of course, open to say, that the
glass tube, upon coming in contact with the filament, retains a charge
of a certain sign upon the point of contact. If now the filament again
touches the glass at the same point while it is oppositely charged, the
charges equalize under evolution of light. But nothing of importance
would be gained by such an explanation. It is unquestionable that the
initial charges given to the atoms or to the glass play some part in
exciting phosphorescence. So, for instance, if a phosphorescent bulb be
first excited by a high frequency coil by connecting it to one of the
terminals of the latter and the degree of luminosity be noted, and then
the bulb be highly charged from a Holtz machine by attaching it
preferably to the positive terminal of the machine, it is found that
when the bulb is again connected to the terminal of the high frequency
coil, the phosphorescence is far more intense. On another occasion I
have considered the possibility of some phosphorescent phenomena in
bulbs being produced by the incandescence of an infinitesimal layer on
the surface of the phosphorescent body. Certainly the impact of the
atoms is powerful enough to produce intense incandescence by the
collisions, since they bring quickly to a high temperature a body of
considerable bulk. If any such effect exists, then the best appliance
for producing phosphorescence in a bulb, which we know so far, is a
disruptive discharge coil giving an enormous potential with but few
fundamental discharges, say 25-30 per second, just enough to produce a
continuous impression upon the eye. It is a fact that such a coil
excites phosphorescence under almost any condition and at all degrees of
exhaustion, and I have observed effects which appear to be due to
phosphorescence even at ordinary pressures of the atmosphere, when the
potentials are extremely high. But if phosphorescent light is produced
by the equalization of charges of electrified atoms (whatever this may
mean ultimately), then the higher the frequency of the impulses or
alternate electrifications, the more economical will be the light
production. It is a long known and noteworthy fact that all the
phosphorescent bodies are poor conductors of electricity and heat, and
that all bodies cease to emit phosphorescent light when they are brought
to a certain temperature. Conductors on the contrary do not possess this
quality. There are but few exceptions to the rule. Carbon is one of
them. Becquerel noted that carbon phosphoresces at a certain elevated
temperature preceding the dark red. This phenomenon may be easily
observed in bulbs provided with a rather large carbon electrode (say, a
sphere of six millimetres diameter). If the current is turned on after a
few seconds, a snow white film covers the electrode, just before it gets
dark red. Similar effects are noted with other conducting bodies, but
many scientific men will probably not attribute them to true
phosphorescence. Whether true incandescence has anything to do with
phosphorescence excited by atomic impact or mechanical shocks still
remains to be decided, but it is a fact that all conditions, which tend
to localize and increase the heating effect at the point of impact, are
almost invariably the most favorable for the production of
phosphorescence. So, if the electrode be very small, which is equivalent
to saying in general, that the electric density is great; if the
potential be high, and if the gas be highly rarefied, all of which
things imply high speed of the projected atoms, or matter, and
consequently violent impacts--the phosphorescence is very intense. If a
bulb provided with a large and small electrode be attached to the
terminal of an induction coil, the small electrode excites
phosphorescence while the large one may not do so, because of the
smaller electric density and hence smaller speed of the atoms. A bulb
provided with a large electrode may be grasped with the hand while the
electrode is connected to the terminal of the coil and it may not
phosphoresce; but if instead of grasping the bulb with the hand, the
same be touched with a pointed wire, the phosphorescence at once
spreads through the bulb, because of the great density at the point of
contact. With low frequencies it seems that gases of great atomic weight
excite more intense phosphorescence than those of smaller weight, as for
instance, hydrogen. With high frequencies the observations are not
sufficiently reliable to draw a conclusion. Oxygen, as is well-known,
produces exceptionally strong effects, which may be in part due to
chemical action. A bulb with hydrogen residue seems to be most easily
excited. Electrodes which are most easily deteriorated produce more
intense phosphorescence in bulbs, but the condition is not permanent
because of the impairment of the vacuum and the deposition of the
electrode matter upon the phosphorescent surfaces. Some liquids, as
oils, for instance, produce magnificent effects of phosphorescence (or
fluorescence?), but they last only a few seconds. So if a bulb has a
trace of oil on the walls and the current is turned on, the
phosphorescence only persists for a few moments until the oil is carried
away. Of all bodies so far tried, sulphide of zinc seems to be the most
susceptible to phosphorescence. Some samples, obtained through the
kindness of Prof. Henry in Paris, were employed in many of these bulbs.
One of the defects of this sulphide is, that it loses its quality of
emitting light when brought to a temperature which is by no means high.
It can therefore, be used only for feeble intensities. An observation
which might deserve notice is, that when violently bombarded from an
aluminum electrode it assumes a black color, but singularly enough, it
returns to the original condition when it cools down.

The most important fact arrived at in pursuing investigations in this
direction is, that in all cases it is necessary, in order to excite
phosphorescence with a minimum amount of energy, to observe certain
conditions. Namely, there is always, no matter what the frequency of the
currents, degree of exhaustion and character of the bodies in the bulb,
a certain potential (assuming the bulb excited from one terminal) or
potential difference (assuming the bulb to be excited with both
terminals) which produces the most economical result. If the potential
be increased, considerable energy may be wasted without producing any
more light, and if it be diminished, then again the light production is
not as economical. The exact condition under which the best result is
obtained seems to depend on many things of a different nature, and it is
to be yet investigated by other experimenters, but it will certainly
have to be observed when such phosphorescent bulbs are operated, if the
best results are to be obtained.

Coming now to the most interesting of these phenomena, the incandescence
or phosphorescence of gases, at low pressures or at the ordinary
pressure of the atmosphere, we must seek the explanation of these
phenomena in the same primary causes, that is, in shocks or impacts of
the atoms. Just as molecules or atoms beating upon a solid body excite
phosphorescence in the same or render it incandescent, so when colliding
among themselves they produce similar phenomena. But this is a very
insufficient explanation and concerns only the crude mechanism. Light is
produced by vibrations which go on at a rate almost inconceivable. If we
compute, from the energy contained in the form of known radiations in a
definite space the force which is necessary to set up such rapid
vibrations, we find, that though the density of the ether be
incomparably smaller than that of any body we know, even hydrogen, the
force is something surpassing comprehension. What is this force, which
in mechanical measure may amount to thousands of tons per square inch?
It is electrostatic force in the light of modern views. It is impossible
to conceive how a body of measurable dimensions could be charged to so
high a potential that the force would be sufficient to produce these
vibrations. Long before any such charge could be imparted to the body it
would be shattered into atoms. The sun emits light and heat, and so does
an ordinary flame or incandescent filament, but in neither of these can
the force be accounted for if it be assumed that it is associated with
the body as a whole. Only in one way may we account for it, namely, by
identifying it with the atom. An atom is so small, that if it be charged
by coming in contact with an electrified body and the charge be assumed
to follow the same law as in the case of bodies of measurable
dimensions, it must retain a quantity of electricity which is fully
capable of accounting for these forces and tremendous rates of
vibration. But the atom behaves singularly in this respect--it always
takes the same "charge."

It is very likely that resonant vibration plays a most important part in
all manifestations of energy in nature. Throughout space all matter is
vibrating, and all rates of vibration are represented, from the lowest
musical note to the highest pitch of the chemical rays, hence an atom,
or complex of atoms, no matter what its period, must find a vibration
with which it is in resonance. When we consider the enormous rapidity
of the light vibrations, we realize the impossibility of producing such
vibrations directly with any apparatus of measurable dimensions, and we
are driven to the only possible means of attaining the object of setting
up waves of light by electrical means and economically, that is, to
affect the molecules or atoms of a gas, to cause them to collide and
vibrate. We then must ask ourselves--How can free molecules or atoms be
affected?

[Illustration: FIG. 196.]

[Illustration: FIG. 197.]

It is a fact that they can be affected by electrostatic force, as is
apparent in many of these experiments. By varying the electrostatic
force we can agitate the atoms, and cause them to collide accompanied by
evolution of heat and light. It is not demonstrated beyond doubt that we
can affect them otherwise. If a luminous discharge is produced in a
closed exhausted tube, do the atoms arrange themselves in obedience to
any other but to electrostatic force acting in straight lines from atom
to atom? Only recently I investigated the mutual action between two
circuits with extreme rates of vibration. When a battery of a few jars
(_c c c c_, Fig. 196) is discharged through a primary P of low
resistance (the connections being as illustrated in Figs. 183_a_, 183_b_
and 183_c_), and the frequency of vibration is many millions there are
great differences of potential between points on the primary not more
than a few inches apart. These differences may be 10,000 volts per inch,
if not more, taking the maximum value of the E. M. F. The secondary _s_
is therefore acted upon by electrostatic induction, which is in such
extreme cases of much greater importance than the electro-dynamic. To
such sudden impulses the primary as well as the secondary are poor
conductors, and therefore great differences of potential may be produced
by electrostatic induction between adjacent points on the secondary.
Then sparks may jump between the wires and streamers become visible in
the dark if the light of the discharge through the spark gap _d d_ be
carefully excluded. If now we substitute a closed vacuum tube for the
metallic secondary _s_, the differences of potential produced in the
tube by electrostatic induction from the primary are fully sufficient to
excite portions of it; but as the points of certain differences of
potential on the primary are not fixed, but are generally constantly
changing in position, a luminous band is produced in the tube,
apparently not touching the glass, as it should, if the points of
maximum and minimum differences of potential were fixed on the primary.
I do not exclude the possibility of such a tube being excited only by
electro-dynamic induction, for very able physicists hold this view; but
in my opinion, there is as yet no positive proof given that atoms of a
gas in a closed tube may arrange themselves in chains under the action
of an electromotive impulse produced by electro-dynamic induction in the
tube. I have been unable so far to produce striae in a tube, however
long, and at whatever degree of exhaustion, that is, striae at right
angles to the supposed direction of the discharge or the axis of the
tube; but I have distinctly observed in a large bulb, in which a wide
luminous band was produced by passing a discharge of a battery through a
wire surrounding the bulb, a circle of feeble luminosity between two
luminous bands, one of which was more intense than the other.
Furthermore, with my present experience I do not think that such a gas
discharge in a closed tube can vibrate, that is, vibrate as a whole. I
am convinced that no discharge through a gas can vibrate. The atoms of a
gas behave very curiously in respect to sudden electric impulses. The
gas does not seem to possess any appreciable inertia to such impulses,
for it is a fact, that the higher the frequency of the impulses, with
the greater freedom does the discharge pass through the gas. If the gas
possesses no inertia then it cannot vibrate, for some inertia is
necessary for the free vibration. I conclude from this that if a
lightning discharge occurs between two clouds, there can be no
oscillation, such as would be expected, considering the capacity of the
clouds. But if the lightning discharge strike the earth, there is always
vibration--in the earth, but not in the cloud. In a gas discharge each
atom vibrates at its own rate, but there is no vibration of the
conducting gaseous mass as a whole. This is an important consideration
in the great problem of producing light economically, for it teaches us
that to reach this result we must use impulses of very high frequency
and necessarily also of high potential. It is a fact that oxygen
produces a more intense light in a tube. Is it because oxygen atoms
possess some inertia and the vibration does not die out instantly? But
then nitrogen should be as good, and chlorine and vapors of many other
bodies much better than oxygen, unless the magnetic properties of the
latter enter prominently into play. Or, is the process in the tube of an
electrolytic nature? Many observations certainly speak for it, the most
important being that matter is always carried away from the electrodes
and the vacuum in a bulb cannot be permanently maintained. If such
process takes place in reality, then again must we take refuge in high
frequencies, for, with such, electrolytic action should be reduced to a
minimum, if not rendered entirely impossible. It is an undeniable fact
that with very high frequencies, provided the impulses be of harmonic
nature, like those obtained from an alternator, there is less
deterioration and the vacua are more permanent. With disruptive
discharge coils there are sudden rises of potential and the vacua are
more quickly impaired, for the electrodes are deteriorated in a very
short time. It was observed in some large tubes, which were provided
with heavy carbon blocks B B_{1}, connected to platinum wires w w_{1}
(as illustrated in Fig. 197), and which were employed in experiments
with the disruptive discharge instead of the ordinary air gap, that the
carbon particles under the action of the powerful magnetic field in
which the tube was placed, were deposited in regular fine lines in the
middle of the tube, as illustrated. These lines were attributed to the
deflection or distortion of the discharge by the magnetic field, but why
the deposit occurred principally where the field was most intense did
not appear quite clear. A fact of interest, likewise noted, was that the
presence of a strong magnetic field increases the deterioration of the
electrodes, probably by reason of the rapid interruptions it produces,
whereby there is actually a higher E. M. F. maintained between the
electrodes.

Much would remain to be said about the luminous effects produced in
gases at low or ordinary pressures. With the present experiences before
us we cannot say that the essential nature of these charming phenomena
is sufficiently known. But investigations in this direction are being
pushed with exceptional ardor. Every line of scientific pursuit has its
fascinations, but electrical investigation appears to possess a
peculiar attraction, for there is no experiment or observation of any
kind in the domain of this wonderful science which would not forcibly
appeal to us. Yet to me it seems, that of all the many marvelous things
we observe, a vacuum tube, excited by an electric impulse from a distant
source, bursting forth out of the darkness and illuminating the room
with its beautiful light, is as lovely a phenomenon as can greet our
eyes. More interesting still it appears when, reducing the fundamental
discharges across the gap to a very small number and waving the tube
about we produce all kinds of designs in luminous lines. So by way of
amusement I take a straight long tube, or a square one, or a square
attached to a straight tube, and by whirling them about in the hand, I
imitate the spokes of a wheel, a Gramme winding, a drum winding, an
alternate current motor winding, etc. (Fig. 198). Viewed from a distance
the effect is weak and much of its beauty is lost, but being near or
holding the tube in the hand, one cannot resist its charm.

[Illustration: FIG. 198.]

In presenting these insignificant results I have not attempted to
arrange and co-ordinate them, as would be proper in a strictly
scientific investigation, in which every succeeding result should be a
logical sequence of the preceding, so that it might be guessed in
advance by the careful reader or attentive listener. I have preferred to
concentrate my energies chiefly upon advancing novel facts or ideas
which might serve as suggestions to others, and this may serve as an
excuse for the lack of harmony. The explanations of the phenomena have
been given in good faith and in the spirit of a student prepared to find
that they admit of a better interpretation. There can be no great harm
in a student taking an erroneous view, but when great minds err, the
world must dearly pay for their mistakes.




CHAPTER XXIX.

TESLA ALTERNATING CURRENT GENERATORS FOR HIGH FREQUENCY, IN DETAIL.


It has become a common practice to operate arc lamps by alternating or
pulsating, as distinguished from continuous, currents; but an objection
which has been raised to such systems exists in the fact that the arcs
emit a pronounced sound, varying with the rate of the alternations or
pulsations of current. This noise is due to the rapidly alternating
heating and cooling, and consequent expansion and contraction, of the
gaseous matter forming the arc, which corresponds with the periods or
impulses of the current. Another disadvantageous feature is found in the
difficulty of maintaining an alternating current arc in consequence of
the periodical increase in resistance corresponding to the periodical
working of the current. This feature entails a further disadvantage,
namely, that small arcs are impracticable.

Theoretical considerations have led Mr. Tesla to the belief that these
disadvantageous features could be obviated by employing currents of a
sufficiently high number of alternations, and his anticipations have
been confirmed in practice. These rapidly alternating currents render it
possible to maintain small arcs which, besides, possess the advantages
of silence and persistency. The latter quality is due to the necessarily
rapid alternations, in consequence of which the arc has no time to cool,
and is always maintained at a high temperature and low resistance.

At the outset of his experiments Mr. Tesla encountered great
difficulties in the construction of high frequency machines. A generator
of this kind is described here, which, though constructed quite some
time ago, is well worthy of a detailed description. It may be mentioned,
in passing, that dynamos of this type have been used by Mr. Tesla in his
lighting researches and experiments with currents of high potential and
high frequency, and reference to them will be found in his lectures
elsewhere printed in this volume.[4]

  [4] See pages 153-4 5.

In the accompanying engravings, Figs. 199 and 200 show the machine,
respectively, in side elevation and vertical cross-section; Figs. 201,
202 and 203 showing enlarged details of construction. As will be seen, A
is an annular magnetic frame, the interior of which is provided with a
large number of pole-pieces D.

Owing to the very large number and small size of the poles and the
spaces between them, the field coils are applied by winding an insulated
conductor F zigzag through the grooves, as shown in Fig. 203, carrying
the wire around the annulus to form as many layers as is desired. In
this way the pole-pieces D will be energized with alternately opposite
polarity around the entire ring.

For the armature, Mr. Tesla employs a spider carrying a ring J, turned
down, except at its edges, to form a trough-like receptacle for a mass
of fine annealed iron wires K, which are wound in the groove to form the
core proper for the armature-coils. Pins L are set in the sides of the
ring J and the coils M are wound over the periphery of the
armature-structure and around the pins. The coils M are connected
together in series, and these terminals N carried through the hollow
shaft H to contact-rings P P, from which the currents are taken off by
brushes O.

[Illustration: FIG. 199.]

In this way a machine with a very large number of poles may be
constructed. It is easy, for instance, to obtain in this manner three
hundred and seventy-five to four hundred poles in a machine that may be
safely driven at a speed of fifteen hundred or sixteen hundred
revolutions per minute, which will produce ten thousand or eleven
thousand alternations of current per second. Arc lamps R R are shown in
the diagram as connected up in series with the machine in Fig. 200. If
such a current be applied to running arc lamps, the sound produced by or
in the arc becomes practically inaudible, for, by increasing the rate of
change in the current, and consequently the number of vibrations per
unit of time of the gaseous material of the arc up to, or beyond, ten
thousand or eleven thousand per second, or to what is regarded as the
limit of audition, the sound due to such vibrations will not be audible.
The exact number of changes or undulations necessary to produce this
result will vary somewhat according to the size of the arc--that is to
say, the smaller the arc, the greater the number of changes that will be
required to render it inaudible within certain limits. It should also be
stated that the arc should not exceed a certain length.

[Illustration: FIGS. 200, 201, 202 and 203.]

The difficulties encountered in the construction of these machines are
of a mechanical as well as an electrical nature. The machines may be
designed on two plans: the field may be formed either of alternating
poles, or of polar projections of the same polarity. Up to about 15,000
alternations per second in an experimental machine, the former plan may
be followed, but a more efficient machine is obtained on the second
plan.

In the machine above described, which was capable of running two arcs of
normal candle power, the field was composed of a ring of wrought iron
32 inches outside diameter, and about 1 inch thick. The inside diameter
was 30 inches. There were 384 polar projections. The wire was wound in
zigzag form, but two wires were wound so as to completely envelop the
projections. The distance between the projections is about 3/16 inch,
and they are a little over 1/16 inch thick. The field magnet was made
relatively small so as to adapt the machine for a constant current.
There are 384 coils connected in two series. It was found impracticable
to use any wire much thicker than No. 26 B. and S. gauge on account of
the local effects. In such a machine the clearance should be as small as
possible; for this reason the machine was made only 1-1/4 inch wide, so
that the binding wires might be obviated. The armature wires must be
wound with great care, as they are apt to fly off in consequence of the
great peripheral speed. In various experiments this machine has been run
as high as 3,000 revolutions per minute. Owing to the great speed it was
possible to obtain as high as 10 amperes out of the machine. The
electromotive force was regulated by means of an adjustable condenser
within very wide limits, the limits being the greater, the greater the
speed. This machine was frequently used to run Mr. Tesla's laboratory
lights.

[Illustration: FIG. 204.]

The machine above described was only one of many such types constructed.
It serves well for an experimental machine, but if still higher
alternations are required and higher efficiency is necessary, then a
machine on a plan shown in Figs. 204 to 207, is preferable. The
principal advantage of this type of machine is that there is not much
magnetic leakage, and that a field may be produced, varying greatly in
intensity in places not much distant from each other.

In these engravings, Figs. 204 and 205 illustrate a machine in which the
armature conductor and field coils are stationary, while the field
magnet core revolves. Fig. 206 shows a machine embodying the same plan
of construction, but having a stationary field magnet and rotary
armature.

The conductor in which the currents are induced may be arranged in
various ways; but Mr. Tesla prefers the following method: He employs an
annular plate of copper D, and by means of a saw cuts in it radial slots
from one edge nearly through to the other, beginning alternately from
opposite edges. In this way a continuous zigzag conductor is formed.
When the polar projections are 1/8 inch wide, the width of the conductor
should not, under any circumstances, be more than 1/32 inch wide; even
then the eddy effect is considerable.

[Illustration: FIG. 205.]

To the inner edge of this plate are secured two rings of non-magnetic
metal E, which are insulated from the copper conductor, but held firmly
thereto by means of the bolts F. Within the rings E is then placed an
annular coil G, which is the energizing coil for the field magnet. The
conductor D and the parts attached thereto are supported by means of the
cylindrical shell or casting A A, the two parts of which are brought
together and clamped to the outer edge of the conductor D.

[Illustration: FIG. 206.]

The core for the field magnet is built up of two circular parts H H,
formed with annular grooves I, which, when the two parts are brought
together, form a space for the reception of the energizing coil G. The
hubs of the cores are trued off, so as to fit closely against one
another, while the outer portions or flanges which form the polar faces
J J, are reduced somewhat in thickness to make room for the conductor D,
and are serrated on their faces. The number of serrations in the polar
faces is arbitrary; but there must exist between them and the radial
portions of the conductor D certain relation, which will be understood
by reference to Fig. 207 in which N N represent the projections or
points on one face of the core of the field, and S S the points of the
other face. The conductor D is shown in this figure in section _a a'_
designating the radial portions of the conductor, and _b_ the insulating
divisions between them. The relative width of the parts _a a'_ and the
space between any two adjacent points N N or S S is such that when the
radial portions _a_ of the conductor are passing between the opposite
points N S where the field is strongest, the intermediate radial
portions _a'_ are passing through the widest spaces midway between such
points and where the field is weakest. Since the core on one side is of
opposite polarity to the part facing it, all the projections of one
polar face will be of opposite polarity to those of the other face.
Hence, although the space between any two adjacent points on the same
face may be extremely small, there will be no leakage of the magnetic
lines between any two points of the same name, but the lines of force
will pass across from one set of points to the other. The construction
followed obviates to a great degree the distortion of the magnetic lines
by the action of the current in the conductor D, in which it will be
observed the current is flowing at any given time from the centre toward
the periphery in one set of radial parts _a_ and in the opposite
direction in the adjacent parts _a'_.

In order to connect the energizing coil G, Fig. 204, with a source of
continuous current, Mr. Tesla utilizes two adjacent radial portions of
the conductor D for connecting the terminals of the coil G with two
binding posts M. For this purpose the plate D is cut entirely through,
as shown, and the break thus made is bridged over by a short conductor
C. The plate D is cut through to form two terminals _d_, which are
connected to binding posts N. The core H H, when rotated by the driving
pulley, generates in the conductors D an alternating current, which is
taken off from the binding posts N.

[Illustration: FIG. 207.]

When it is desired to rotate the conductor between the faces of a
stationary field magnet, the construction shown in Fig. 206, is adopted.
The conductor D in this case is or may be made in substantially the same
manner as above described by slotting an annular conducting-plate and
supporting it between two heads O, held together by bolts _o_ and fixed
to the driving-shaft K. The inner edge of the plate or conductor D is
preferably flanged to secure a firmer union between it and the heads O.
It is insulated from the head. The field-magnet in this case consists of
two annular parts H H, provided with annular grooves I for the reception
of the coils. The flanges or faces surrounding the annular groove are
brought together, while the inner flanges are serrated, as in the
previous case, and form the polar faces. The two parts H H are formed
with a base R, upon which the machine rests. S S are non-magnetic
bushings secured or set in the central opening of the cores. The
conductor D is cut entirely through at one point to form terminals, from
which insulated conductors T are led through the shaft to
collecting-rings V.

In one type of machine of this kind constructed by Mr. Tesla, the field
had 480 polar projections on each side, and from this machine it was
possible to obtain 30,000 alternations per second. As the polar
projections must necessarily be very narrow, very thin wires or sheets
must be used to avoid the eddy current effects. Mr. Tesla has thus
constructed machines with a stationary armature and rotating field, in
which case also the field-coil was supported so that the revolving part
consisted only of a wrought iron body devoid of any wire and also
machines with a rotating armature and stationary field. The machines may
be either drum or disc, but Mr. Tesla's experience shows the latter to
be preferable.

       *       *       *       *       *

In the course of a very interesting article contributed to the
_Electrical World_ in February, 1891, Mr. Tesla makes some suggestive
remarks on these high frequency machines and his experiences with them,
as well as with other parts of the high frequency apparatus. Part of it
is quoted here and is as follows:--

The writer will incidentally mention that any one who attempts for the
first time to construct such a machine will have a tale of woe to tell.
He will first start out, as a matter of course, by making an armature
with the required number of polar projections. He will then get the
satisfaction of having produced an apparatus which is fit to accompany a
thoroughly Wagnerian opera. It may besides possess the virtue of
converting mechanical energy into heat in a nearly perfect manner. If
there is a reversal in the polarity of the projections, he will get heat
out of the machine; if there is no reversal, the heating will be less,
but the output will be next to nothing. He will then abandon the iron in
the armature, and he will get from the Scylla to the Charybdis. He will
look for one difficulty and will find another, but, after a few trials,
he may get nearly what he wanted.

Among the many experiments which may be performed with such a machine,
of not the least interest are those performed with a high-tension
induction coil. The character of the discharge is completely changed.
The arc is established at much greater distances, and it is so easily
affected by the slightest current of air that it often wriggles around
in the most singular manner. It usually emits the rhythmical sound
peculiar to the alternate current arcs, but the curious point is that
the sound may be heard with a number of alternations far above ten
thousand per second, which by many is considered to be about the limit
of audition. In many respects the coil behaves like a static machine.
Points impair considerably the sparking interval, electricity escaping
from them freely, and from a wire attached to one of the terminals
streams of light issue, as though it were connected to a pole of a
powerful Toepler machine. All these phenomena are, of course, mostly due
to the enormous differences of potential obtained. As a consequence of
the self-induction of the coil and the high frequency, the current is
minute while there is a corresponding rise of pressure. A current
impulse of some strength started in such a coil should persist to flow
no less than four ten-thousandths of a second. As this time is greater
than half the period, it occurs that an opposing electromotive force
begins to act while the current is still flowing. As a consequence, the
pressure rises as in a tube filled with liquid and vibrated rapidly
around its axis. The current is so small that, in the opinion and
involuntary experience of the writer, the discharge of even a very large
coil cannot produce seriously injurious effects, whereas, if the same
coil were operated with a current of lower frequency, though the
electromotive force would be much smaller, the discharge would be most
certainly injurious. This result, however, is due in part to the high
frequency. The writer's experiences tend to show that the higher the
frequency the greater the amount of electrical energy which may be
passed through the body without serious discomfort; whence it seems
certain that human tissues act as condensers.

One is not quite prepared for the behavior of the coil when connected to
a Leyden jar. One, of course, anticipates that since the frequency is
high the capacity of the jar should be small. He therefore takes a very
small jar, about the size of a small wine glass, but he finds that even
with this jar the coil is practically short-circuited. He then reduces
the capacity until he comes to about the capacity of two spheres, say,
ten centimetres in diameter and two to four centimetres apart. The
discharge then assumes the form of a serrated band exactly like a
succession of sparks viewed in a rapidly revolving mirror; the
serrations, of course, corresponding to the condenser discharges. In
this case one may observe a queer phenomenon. The discharge starts at
the nearest points, works gradually up, breaks somewhere near the top of
the spheres, begins again at the bottom, and so on. This goes on so fast
that several serrated bands are seen at once. One may be puzzled for a
few minutes, but the explanation is simple enough. The discharge begins
at the nearest points, the air is heated and carries the arc upward
until it breaks, when it is re-established at the nearest points, etc.
Since the current passes easily through a condenser of even small
capacity, it will be found quite natural that connecting only one
terminal to a body of the same size, no matter how well insulated,
impairs considerably the striking distance of the arc.

Experiments with Geissler tubes are of special interest. An exhausted
tube, devoid of electrodes of any kind, will light up at some distance
from the coil. If a tube from a vacuum pump is near the coil the whole
of the pump is brilliantly lighted. An incandescent lamp approached to
the coil lights up and gets perceptibly hot. If a lamp have the
terminals connected to one of the binding posts of the coil and the hand
is approached to the bulb, a very curious and rather unpleasant
discharge from the glass to the hand takes place, and the filament may
become incandescent. The discharge resembles to some extent the stream
issuing from the plates of a powerful Toepler machine, but is of
incomparably greater quantity. The lamp in this case acts as a
condenser, the rarefied gas being one coating, the operator's hand the
other. By taking the globe of a lamp in the hand, and by bringing the
metallic terminals near to or in contact with a conductor connected to
the coil, the carbon is brought to bright incandescence and the glass is
rapidly heated. With a 100-volt 10 C. P. lamp one may without great
discomfort stand as much current as will bring the lamp to a
considerable brilliancy; but it can be held in the hand only for a few
minutes, as the glass is heated in an incredibly short time. When a tube
is lighted by bringing it near to the coil it may be made to go out by
interposing a metal plate on the hand between the coil and tube; but if
the metal plate be fastened to a glass rod or otherwise insulated, the
tube may remain lighted if the plate be interposed, or may even
increase in luminosity. The effect depends on the position of the plate
and tube relatively to the coil, and may be always easily foretold by
_assuming_ that conduction takes place from one terminal of the coil to
the other. According to the position of the plate, it may either divert
from or direct the current to the tube.

In another line of work the writer has in frequent experiments
maintained incandescent lamps of 50 or 100 volts burning at any desired
candle power with both the terminals of each lamp connected to a stout
copper wire of no more than a few feet in length. These experiments seem
interesting enough, but they are not more so than the queer experiment
of Faraday, which has been revived and made much of by recent
investigators, and in which a discharge is made to jump between two
points of a bent copper wire. An experiment may be cited here which may
seem equally interesting. If a Geissler tube, the terminals of which are
joined by a copper wire, be approached to the coil, certainly no one
would be prepared to see the tube light up. Curiously enough, it does
light up, and, what is more, the wire does not seem to make much
difference. Now one is apt to think in the first moment that the
impedance of the wire might have something to do with the phenomenon.
But this is of course immediately rejected, as for this an enormous
frequency would be required. This result, however, seems puzzling only
at first; for upon reflection it is quite clear that the wire can make
but little difference. It may be explained in more than one way, but it
agrees perhaps best with observation to assume that conduction takes
place from the terminals of the coil through the space. On this
assumption, if the tube with the wire be held in any position, the wire
can divert little more than the current which passes through the space
occupied by the wire and the metallic terminals of the tube; through the
adjacent space the current passes practically undisturbed. For this
reason, if the tube be held in any position at right angles to the line
joining the binding posts of the coil, the wire makes hardly any
difference, but in a position more or less parallel with that line it
impairs to a certain extent the brilliancy of the tube and its facility
to light up. Numerous other phenomena may be explained on the same
assumption. For instance, if the ends of the tube be provided with
washers of sufficient size and held in the line joining the terminals of
the coil, it will not light up, and then nearly the whole of the
current, which would otherwise pass uniformly through the space between
the washers, is diverted through the wire. But if the tube be inclined
sufficiently to that line, it will light up in spite of the washers.
Also, if a metal plate be fastened upon a glass rod and held at right
angles to the line joining the binding posts, and nearer to one of them,
a tube held more or less parallel with the line will light up instantly
when one of the terminals touches the plate, and will go out when
separated from the plate. The greater the surface of the plate, up to a
certain limit, the easier the tube will light up. When a tube is placed
at right angles to the straight line joining the binding posts, and then
rotated, its luminosity steadily increases until it is parallel with
that line. The writer must state, however, that he does not favor the
idea of a leakage or current through the space any more than as a
suitable explanation, for he is convinced that all these experiments
could not be performed with a static machine yielding a constant
difference of potential, and that condenser action is largely concerned
in these phenomena.

It is well to take certain precautions when operating a Ruhmkorff coil
with very rapidly alternating currents. The primary current should not
be turned on too long, else the core may get so hot as to melt the
gutta-percha or paraffin, or otherwise injure the insulation, and this
may occur in a surprisingly short time, considering the current's
strength. The primary current being turned on, the fine wire terminals
may be joined without great risk, the impedance being so great that it
is difficult to force enough current through the fine wire so as to
injure it, and in fact the coil may be on the whole much safer when the
terminals of the fine wire are connected than when they are insulated;
but special care should be taken when the terminals are connected to the
coatings of a Leyden jar, for with anywhere near the critical capacity,
which just counteracts the self-induction at the existing frequency, the
coil might meet the fate of St. Polycarpus. If an expensive vacuum pump
is lighted up by being near to the coil or touched with a wire connected
to one of the terminals, the current should be left on no more than a
few moments, else the glass will be cracked by the heating of the
rarefied gas in one of the narrow passages--in the writer's own
experience _quod erat demonstrandum_.[5]

  [5] It is thought necessary to remark that, although the induction
      coil may give quite a good result when operated with such
      rapidly alternating currents, yet its construction, quite
      irrespective of the iron core, makes it very unfit for such
      high frequencies, and to obtain the best results the
      construction should be greatly modified.

There are a good many other points of interest which may be observed in
connection with such a machine. Experiments with the telephone, a
conductor in a strong field or with a condenser or arc, seem to afford
certain proof that sounds far above the usual accepted limit of hearing
would be perceived. A telephone will emit notes of twelve to thirteen
thousand vibrations per second; then the inability of the core to follow
such rapid alternations begins to tell. If, however, the magnet and core
be replaced by a condenser and the terminals connected to the
high-tension secondary of a transformer, higher notes may still be
heard. If the current be sent around a finely laminated core and a small
piece of thin sheet iron be held gently against the core, a sound may be
still heard with thirteen to fourteen thousand alternations per second,
provided the current is sufficiently strong. A small coil, however,
tightly packed between the poles of a powerful magnet, will emit a sound
with the above number of alternations, and arcs may be audible with a
still higher frequency. The limit of audition is variously estimated. In
Sir William Thomson's writings it is stated somewhere that ten thousand
per second, or nearly so, is the limit. Other, but less reliable,
sources give it as high as twenty-four thousand per second. The above
experiments have convinced the writer that notes of an incomparably
higher number of vibrations per second would be perceived provided they
could be produced with sufficient power. There is no reason why it
should not be so. The condensations and rarefactions of the air would
necessarily set the diaphragm in a corresponding vibration and some
sensation would be produced, whatever--within certain limits--the
velocity of transmission to their nerve centres, though it is probable
that for want of exercise the ear would not be able to distinguish any
such high note. With the eye it is different; if the sense of vision is
based upon some resonance effect, as many believe, no amount of increase
in the intensity of the ethereal vibration could extend our range of
vision on either side of the visible spectrum.

The limit of audition of an arc depends on its size. The greater the
surface by a given heating effect in the arc, the higher the limit of
audition. The highest notes are emitted by the high-tension discharges
of an induction coil in which the arc is, so to speak, all surface. If
_R_ be the resistance of an arc, and _C_ the current, and the linear
dimensions be _n_ times increased, then the resistance is _R_/_n_, and
with the same current density the current would be _n_^2_C_; hence the
heating effect is _n_^3 times greater, while the surface is only _n_^2
times as great. For this reason very large arcs would not emit any
rhythmical sound even with a very low frequency. It must be observed,
however, that the sound emitted depends to some extent also on the
composition of the carbon. If the carbon contain highly refractory
material, this, when heated, tends to maintain the temperature of the
arc uniform and the sound is lessened; for this reason it would seem
that an alternating arc requires such carbons.

With currents of such high frequencies it is possible to obtain
noiseless arcs, but the regulation of the lamp is rendered extremely
difficult on account of the excessively small attractions or repulsions
between conductors conveying these currents.

An interesting feature of the arc produced by these rapidly alternating
currents is its persistency. There are two causes for it, one of which
is always present, the other sometimes only. One is due to the character
of the current and the other to a property of the machine. The first
cause is the more important one, and is due directly to the rapidity of
the alternations. When an arc is formed by a periodically undulating
current, there is a corresponding undulation in the temperature of the
gaseous column, and, therefore, a corresponding undulation in the
resistance of the arc. But the resistance of the arc varies enormously
with the temperature of the gaseous column, being practically infinite
when the gas between the electrodes is cold. The persistence of the arc,
therefore, depends on the inability of the column to cool. It is for
this reason impossible to maintain an arc with the current alternating
only a few times a second. On the other hand, with a practically
continuous current, the arc is easily maintained, the column being
constantly kept at a high temperature and low resistance. The higher the
frequency the smaller the time interval during which the arc may cool
and increase considerably in resistance. With a frequency of 10,000 per
second or more in an arc of equal size excessively small variations of
temperature are superimposed upon a steady temperature, like ripples on
the surface of a deep sea. The heating effect is practically continuous
and the arc behaves like one produced by a continuous current, with the
exception, however, that it may not be quite as easily started, and that
the electrodes are equally consumed; though the writer has observed
some irregularities in this respect.

The second cause alluded to, which possibly may not be present, is due
to the tendency of a machine of such high frequency to maintain a
practically constant current. When the arc is lengthened, the
electromotive force rises in proportion and the arc appears to be more
persistent.

Such a machine is eminently adapted to maintain a constant current, but
it is very unfit for a constant potential. As a matter of fact, in
certain types of such machines a nearly constant current is an almost
unavoidable result. As the number of poles or polar projections is
greatly increased, the clearance becomes of great importance. One has
really to do with a great number of very small machines. Then there is
the impedance in the armature, enormously augmented by the high
frequency. Then, again, the magnetic leakage is facilitated. If there
are three or four hundred alternate poles, the leakage is so great that
it is virtually the same as connecting, in a two-pole machine, the poles
by a piece of iron. This disadvantage, it is true, may be obviated more
or less by using a field throughout of the same polarity, but then one
encounters difficulties of a different nature. All these things tend to
maintain a constant current in the armature circuit.

In this connection it is interesting to notice that even to-day
engineers are astonished at the performance of a constant current
machine, just as, some years ago, they used to consider it an
extraordinary performance if a machine was capable of maintaining a
constant potential difference between the terminals. Yet one result is
just as easily secured as the other. It must only be remembered that in
an inductive apparatus of any kind, if constant potential is required,
the inductive relation between the primary or exciting and secondary or
armature circuit must be the closest possible; whereas, in an apparatus
for constant current just the opposite is required. Furthermore, the
opposition to the current's flow in the induced circuit must be as small
as possible in the former and as great as possible in the latter case.
But opposition to a current's flow may be caused in more than one way.
It may be caused by ohmic resistance or self-induction. One may make the
induced circuit of a dynamo machine or transformer of such high
resistance that when operating devices of considerably smaller
resistance within very wide limits a nearly constant current is
maintained. But such high resistance involves a great loss in power,
hence it is not practicable. Not so self-induction. Self-induction does
not necessarily mean loss of power. The moral is, use self-induction
instead of resistance. There is, however, a circumstance which favors
the adoption of this plan, and this is, that a very high self-induction
may be obtained cheaply by surrounding a comparatively small length of
wire more or less completely with iron, and, furthermore, the effect may
be exalted at will by causing a rapid undulation of the current. To sum
up, the requirements for constant current are: Weak magnetic connection
between the induced and inducing circuits, greatest possible
self-induction with the least resistance, greatest practicable rate of
change of the current. Constant potential, on the other hand, requires:
Closest magnetic connection between the circuits, steady induced
current, and, if possible, no reaction. If the latter conditions could
be fully satisfied in a constant potential machine, its output would
surpass many times that of a machine primarily designed to give constant
current. Unfortunately, the type of machine in which these conditions
may be satisfied is of little practical value, owing to the small
electromotive force obtainable and the difficulties in taking off the
current.

With their keen inventor's instinct, the now successful arc-light men
have early recognized the desiderata of a constant current machine.
Their arc light machines have weak fields, large armatures, with a great
length of copper wire and few commutator segments to produce great
variations in the current's strength and to bring self-induction into
play. Such machines may maintain within considerable limits of variation
in the resistance of the circuit a practically constant current. Their
output is of course correspondingly diminished, and, perhaps with the
object in view not to cut down the output too much, a simple device
compensating exceptional variations is employed. The undulation of the
current is almost essential to the commercial success of an arc-light
system. It introduces in the circuit a steadying element taking the
place of a large ohmic resistance, without involving a great loss in
power, and, what is more important, it allows the use of simple clutch
lamps, which with a current of a certain number of impulses per second,
best suitable for each particular lamp, will, if properly attended to,
regulate even better than the finest clock-work lamps. This discovery
has been made by the writer--several years too late.

It has been asserted by competent English electricians that in a
constant-current machine or transformer the regulation is effected by
varying the phase of the secondary current. That this view is erroneous
may be easily proved by using, instead of lamps, devices each possessing
self-induction and capacity or self-induction and resistance--that is,
retarding and accelerating components--in such proportions as to not
affect materially the phase of the secondary current. Any number of such
devices may be inserted or cut out, still it will be found that the
regulation occurs, a constant current being maintained, while the
electromotive force is varied with the number of the devices. The change
of phase of the secondary current is simply a result following from the
changes in resistance, and, though secondary reaction is always of more
or less importance, yet the real cause of the regulation lies in the
existence of the conditions above enumerated. It should be stated,
however, that in the case of a machine the above remarks are to be
restricted to the cases in which the machine is independently excited.
If the excitation be effected by commutating the armature current, then
the fixed position of the brushes makes any shifting of the neutral line
of the utmost importance, and it may not be thought immodest of the
writer to mention that, as far as records go, he seems to have been the
first who has successfully regulated machines by providing a bridge
connection between a point of the external circuit and the commutator by
means of a third brush. The armature and field being properly
proportioned and the brushes placed in their determined positions, a
constant current or constant potential resulted from the shifting of the
diameter of commutation by the varying loads.

In connection with machines of such high frequencies, the condenser
affords an especially interesting study. It is easy to raise the
electromotive force of such a machine to four or five times the value by
simply connecting the condenser to the circuit, and the writer has
continually used the condenser for the the purposes of regulation, as
suggested by Blakesley in his book on alternate currents, in which he
has treated the most frequently occurring condenser problems with
exquisite simplicity and clearness. The high frequency allows the use of
small capacities and renders investigation easy. But, although in most
of the experiments the result may be foretold, some phenomena observed
seem at first curious. One experiment performed three or four months ago
with such a machine and a condenser may serve as an illustration. A
machine was used giving about 20,000 alternations per second. Two bare
wires about twenty feet long and two millimetres in diameter, in close
proximity to each other, were connected to the terminals of the machine
at the one end, and to a condenser at the other. A small transformer
without an iron core, of course, was used to bring the reading within
range of a Cardew voltmeter by connecting the voltmeter to the
secondary. On the terminals of the condenser the electromotive force was
about 120 volts, and from there inch by inch it gradually fell until at
the terminals of the machine it was about 65 volts. It was virtually as
though the condenser were a generator, and the line and armature circuit
simply a resistance connected to it. The writer looked for a case of
resonance, but he was unable to augment the effect by varying the
capacity very carefully and gradually or by changing the speed of the
machine. A case of pure resonance he was unable to obtain. When a
condenser was connected to the terminals of the machine--the
self-induction of the armature being first determined in the maximum and
minimum position and the mean value taken--the capacity which gave the
highest electromotive force corresponded most nearly to that which just
counteracted the self-induction with the existing frequency. If the
capacity was increased or diminished, the electromotive force fell as
expected.

With frequencies as high as the above mentioned, the condenser effects
are of enormous importance. The condenser becomes a highly efficient
apparatus capable of transferring considerable energy.

       *       *       *       *       *

In an appendix to this book will be found a description of the Tesla
oscillator, which its inventor believes will among other great
advantages give him the necessary high frequency conditions, while
relieving him of the inconveniences that attach to generators of the
type described at the beginning of this chapter.




CHAPTER XXX.

ALTERNATE CURRENT ELECTROSTATIC INDUCTION APPARATUS.[6]


  [6] Article by Mr. Tesla in _The Electrical Engineer_, N. Y.,
      May 6, 1891.

About a year and a half ago while engaged in the study of alternate
currents of short period, it occurred to me that such currents could be
obtained by rotating charged surfaces in close proximity to conductors.
Accordingly I devised various forms of experimental apparatus of which
two are illustrated in the accompanying engravings.

[Illustration: FIG. 208.]

In the apparatus shown in Fig. 208, A is a ring of dry shellacked hard
wood provided on its inside with two sets of tin-foil coatings, _a_ and
_b_, all the _a_ coatings and all the _b_ coatings being connected
together, respectively, but independent from each other. These two sets
of coatings are connected to two terminals, T. For the sake of
clearness only a few coatings are shown. Inside of the ring A, and in
close proximity to it there is arranged to rotate a cylinder B, likewise
of dry, shellacked hard wood, and provided with two similar sets of
coatings, _a^1_ and _b^1_, all the coatings _a^1_ being connected to one
ring and all the others, _b^1_, to another marked + and -. These two
sets, _a^1_ and _b^1_ are charged to a high potential by a Holtz or
Wimshurst machine, and may be connected to a jar of some capacity. The
inside of ring A is coated with mica in order to increase the induction
and also to allow higher potentials to be used.

[Illustration: FIG. 209.]

When the cylinder B with the charged coatings is rotated, a circuit
connected to the terminals T is traversed by alternating currents.
Another form of apparatus is illustrated in Fig. 209. In this apparatus
the two sets of tin-foil coatings are glued on a plate of ebonite, and a
similar plate which is rotated, and the coatings of which are charged as
in Fig. 208, is provided.

The output of such an apparatus is very small, but some of the effects
peculiar to alternating currents of short periods may be observed. The
effects, however, cannot be compared with those obtainable with an
induction coil which is operated by an alternate current machine of high
frequency, some of which were described by me a short while ago.




CHAPTER XXXI.

"MASSAGE" WITH CURRENTS OF HIGH FREQUENCY.[7]

  [7] Article by Mr. Tesla in _The Electrical Engineer_ of Dec. 23d,
      1891.

I trust that the present brief communication will not be interpreted as
an effort on my part to put myself on record as a "patent medicine" man,
for a serious worker cannot despise anything more than the misuse and
abuse of electricity which we have frequent occasion to witness. My
remarks are elicited by the lively interest which prominent medical
practitioners evince at every real advance in electrical investigation.
The progress in recent years has been so great that every electrician
and electrical engineer is confident that electricity will become the
means of accomplishing many things that have been heretofore, with our
existing knowledge, deemed impossible. No wonder then that progressive
physicians also should expect to find in it a powerful tool and help in
new curative processes. Since I had the honor to bring before the
American Institute of Electrical Engineers some results in utilizing
alternating currents of high tension, I have received many letters from
noted physicians inquiring as to the physical effects of such currents
of high frequency. It may be remembered that I then demonstrated that a
body perfectly well insulated in air can be heated by simply connecting
it with a source of rapidly alternating high potential. The heating in
this case is due in all probability to the bombardment of the body by
air, or possibly by some other medium, which is molecular or atomic in
construction, and the presence of which has so far escaped our
analysis--for according to my ideas, the true ether radiation with such
frequencies as even a few millions per second must be very small. This
body may be a good conductor or it may be a very poor conductor of
electricity with little change in the result. The human body is, in such
a case, a fine conductor, and if a person insulated in a room, or no
matter where, is brought into contact with such a source of rapidly
alternating high potential, the skin is heated by bombardment. It is a
mere question of the dimensions and character of the apparatus to
produce any degree of heating desired.

It has occurred to me whether, with such apparatus properly prepared, it
would not be possible for a skilled physician to find in it a means for
the effective treatment of various types of disease. The heating will,
of course, be superficial, that is, on the skin, and would result,
whether the person operated on were in bed or walking around a room,
whether dressed in thick clothes or whether reduced to nakedness. In
fact, to put it broadly, it is conceivable that a person entirely nude
at the North Pole might keep himself comfortably warm in this manner.

Without vouching for all the results, which must, of course, be
determined by experience and observation, I can at least warrant the
fact that heating would occur by the use of this method of subjecting
the human body to bombardment by alternating currents of high potential
and frequency such I have long worked with. It is only reasonable to
expect that some of the novel effects will be wholly different from
those obtainable with the old familiar therapeutic methods generally
used. Whether they would all be beneficial or not remains to be proved.




CHAPTER XXXII.

ELECTRIC DISCHARGE IN VACUUM TUBES.[8]

  [8] Article by Mr. Tesla in _The Electrical Engineer_. N. Y.,
      July 1, 1891.


In _The Electrical Engineer_ of June 10 I have noted the description of
some experiments of Prof. J. J. Thomson, on the "Electric Discharge in
Vacuum Tubes," and in your issue of June 24 Prof. Elihu Thomson
describes an experiment of the same kind. The fundamental idea in these
experiments is to set up an electromotive force in a vacuum
tube---preferably devoid of any electrodes--by means of electro-magnetic
induction, and to excite the tube in this manner.

As I view the subject I should, think that to any experimenter who had
carefully studied the problem confronting us and who attempted to find a
solution of it, this idea must present itself as naturally as, for
instance, the idea of replacing the tinfoil coatings of a Leyden jar by
rarefied gas and exciting luminosity in the condenser thus obtained by
repeatedly charging and discharging it. The idea being obvious, whatever
merit there is in this line of investigation must depend upon the
completeness of the study of the subject and the correctness of the
observations. The following lines are not penned with any desire on my
part to put myself on record as one who has performed similar
experiments, but with a desire to assist other experimenters by pointing
out certain peculiarities of the phenomena observed, which, to all
appearances, have not been noted by Prof. J. J. Thomson, who, however,
seems to have gone about systematically in his investigations, and who
has been the first to make his results known. These peculiarities noted
by me would seem to be at variance with the views of Prof. J. J.
Thomson, and present the phenomena in a different light.

My investigations in this line occupied me principally during the winter
and spring of the past year. During this time many different experiments
were performed, and in my exchanges of ideas on this subject with Mr.
Alfred S. Brown, of the Western Union Telegraph Company, various
different dispositions were suggested which were carried out by me in
practice. Fig. 210 may serve as an example of one of the many forms of
apparatus used. This consisted of a large glass tube sealed at one end
and projecting into an ordinary incandescent lamp bulb. The primary,
usually consisting of a few turns of thick, well-insulated copper sheet
was inserted within the tube, the inside space of the bulb furnishing
the secondary. This form of apparatus was arrived at after some
experimenting, and was used principally with the view of enabling me to
place a polished reflecting surface on the inside of the tube, and for
this purpose the last turn of the primary was covered with a thin silver
sheet. In all forms of apparatus used there was no special difficulty in
exciting a luminous circle or cylinder in proximity to the primary.

[Illustration: FIG. 210.]

As to the number of turns, I cannot quite understand why Prof. J. J.
Thomson should think that a few turns were "quite sufficient," but lest
I should impute to him an opinion he may not have, I will add that I
have gained this impression from the reading of the published abstracts
of his lecture. Clearly, the number of turns which gives the best result
in any case, is dependent on the dimensions of the apparatus, and, were
it not for various considerations, one turn would always give the best
result.

I have found that it is preferable to use in these experiments an
alternate current machine giving a moderate number of alternations per
second to excite the induction coil for charging the Leyden jar which
discharges through the primary--shown diagrammatically in Fig. 211,--as
in such case, before the disruptive discharge takes place, the tube or
bulb is slightly excited and the formation of the luminous circle is
decidedly facilitated. But I have also used a Wimshurst machine in some
experiments.

[Illustration: FIG. 211.]

Prof. J. J. Thomson's view of the phenomena under consideration seems to
be that they are wholly due to electro-magnetic action. I was, at one
time, of the same opinion, but upon carefully investigating the subject
I was led to the conviction that they are more of an electrostatic
nature. It must be remembered that in these experiments we have to deal
with primary currents of an enormous frequency or rate of change and of
high potential, and that the secondary conductor consists of a rarefied
gas, and that under such conditions electrostatic effects must play an
important part.

[Illustration: FIG. 212.]

In support of my view I will describe a few experiments made by me. To
excite luminosity in the tube it is not absolutely necessary that the
conductor should be closed. For instance, if an ordinary exhausted tube
(preferably of large diameter) be surrounded by a spiral of thick copper
wire serving as the primary, a feebly luminous spiral may be induced in
the tube, roughly shown in Fig. 212. In one of these experiments a
curious phenomenon was observed; namely, two intensely luminous circles,
each of them close to a turn of the primary spiral, were formed inside
of the tube, and I attributed this phenomenon to the existence of nodes
on the primary. The circles were connected by a faint luminous spiral
parallel to the primary and in close proximity to it. To produce this
effect I have found it necessary to strain the jar to the utmost. The
turns of the spiral tend to close and form circles, but this, of course,
would be expected, and does not necessarily indicate an electro-magnetic
effect; Whereas the fact that a glow can be produced along the primary
in the form of an open spiral argues for an electrostatic effect.

[Illustration: FIG. 213.]

In using Dr. Lodge's recoil circuit, the electrostatic action is
likewise apparent. The arrangement is illustrated in Fig. 213. In his
experiment two hollow exhausted tubes H H were slipped over the wires of
the recoil circuit and upon discharging the jar in the usual manner
luminosity was excited in the tubes.

Another experiment performed is illustrated in Fig. 214. In this case an
ordinary lamp-bulb was surrounded by one or two turns of thick copper
wire P and the luminous circle L excited in the bulb by discharging the
jar through the primary. The lamp-bulb was provided with a tinfoil
coating on the side opposite to the primary and each time the tinfoil
coating was connected to the ground or to a large object the luminosity
of the circle was considerably increased. This was evidently due to
electrostatic action.

In other experiments I have noted that when the primary touches the
glass the luminous circle is easier produced and is more sharply
defined; but I have not noted that, generally speaking, the circles
induced were very sharply defined, as Prof. J. J. Thomson has observed;
on the contrary, in my experiments they were broad and often the whole
of the bulb or tube was illuminated; and in one case I have observed an
intensely purplish glow, to which Prof. J. J. Thomson refers. But the
circles were always in close proximity to the primary and were
considerably easier produced when the latter was very close to the
glass, much more so than would be expected assuming the action to be
electromagnetic and considering the distance; and these facts speak for
an electrostatic effect.

[Illustration: FIG. 214.]

[Illustration: FIG. 215.]

Furthermore I have observed that there is a molecular bombardment in the
plane of the luminous circle at right angles to the glass--supposing the
circle to be in the plane of the primary--this bombardment being
evident from the rapid heating of the glass near the primary. Were the
bombardment not at right angles to the glass the heating could not be so
rapid. If there is a circumferential movement of the molecules
constituting the luminous circle, I have thought that it might be
rendered manifest by placing within the tube or bulb, radially to the
circle, a thin plate of mica coated with some phosphorescent material
and another such plate tangentially to the circle. If the molecules
would move circumferentially, the former plate would be rendered more
intensely phosphorescent. For want of time I have, however, not been
able to perform the experiment.

Another observation made by me was that when the specific inductive
capacity of the medium between the primary and secondary is increased,
the inductive effect is augmented. This is roughly illustrated in Fig.
215. In this case luminosity was excited in an exhausted tube or bulb B
and a glass tube T slipped between the primary and the bulb, when the
effect pointed out was noted. Were the action wholly electromagnetic no
change could possibly have been observed.

I have likewise noted that when a bulb is surrounded by a wire closed
upon itself and in the plane of the primary, the formation of the
luminous circle within the bulb is not prevented. But if instead of the
wire a broad strip of tinfoil is glued upon the bulb, the formation of
the luminous band was prevented, because then the action was distributed
over a greater surface. The effect of the closed tinfoil was no doubt of
an electrostatic nature, for it presented a much greater resistance than
the closed wire and produced therefore a much smaller electromagnetic
effect.

Some of the experiments of Prof. J. J. Thomson also would seem to show
some electrostatic action. For instance, in the experiment with the bulb
enclosed in a bell jar, I should think that when the latter is exhausted
so far that the gas enclosed reaches the maximum conductivity, the
formation of the circle in the bulb and jar is prevented because of the
space surrounding the primary being highly conducting; when the jar is
further exhausted, the conductivity of the space around the primary
diminishes and the circles appear necessarily first in the bell jar, as
the rarefied gas is nearer to the primary. But were the inductive effect
very powerful, they would probably appear in the bulb also. If, however,
the bell jar were exhausted to the highest degree they would very likely
show themselves in the bulb only, that is, supposing the vacuous space
to be non-conducting. On the assumption that in these phenomena
electrostatic actions are concerned we find it easily explicable why the
introduction of mercury or the heating of the bulb prevents the
formation of the luminous band or shortens the after-glow; and also why
in some cases a platinum wire may prevent the excitation of the tube.
Nevertheless some of the experiments of Prof. J. J. Thomson would seem
to indicate an electromagnetic effect. I may add that in one of my
experiments in which a vacuum was produced by the Torricellian method, I
was unable to produce the luminous band, but this may have been due to
the weak exciting current employed.

My principal argument is the following: I have experimentally proved
that if the same discharge which is barely sufficient to excite a
luminous band in the bulb when passed through the primary circuit be so
directed as to exalt the electrostatic inductive effect--namely, by
converting upwards--an exhausted tube, devoid of electrodes, may be
excited at a distance of several feet.


SOME EXPERIMENTS ON THE ELECTRIC DISCHARGE IN VACUUM TUBES.[9]

BY PROF. J. J. THOMSON, M.A., F.R.S.

  [9] Abstract of a paper read before Physical Society of London.

    [Illustration: FIG. 216.]

    [Illustration: FIG. 217.]

    [Illustration: FIG. 218.]

    [Illustration: FIG. 219.]

    The phenomena of vacuum discharges were, Prof. Thomson said,
    greatly simplified when their path was wholly gaseous, the
    complication of the dark space surrounding the negative electrode,
    and the stratifications so commonly observed in ordinary vacuum
    tubes, being absent. To produce discharges in tubes devoid of
    electrodes was, however, not easy to accomplish, for the only
    available means of producing an electromotive force in the
    discharge circuit was by electro-magnetic induction. Ordinary
    methods of producing variable induction were valueless, and
    recourse was had to the oscillatory discharge of a Leyden jar,
    which combines the two essentials of a current whose maximum value
    is enormous, and whose rapidity of alternation is immensely great.
    The discharge circuits, which may take the shape of bulbs, or of
    tubes bent in the form of coils, were placed in close proximity to
    glass tubes filled with mercury, which formed the path of the
    oscillatory discharge. The parts thus corresponded to the windings
    of an induction coil, the vacuum tubes being the secondary, and the
    tubes filled with mercury the primary. In such an apparatus the
    Leyden jar need not be large, and neither primary nor secondary
    need have many turns, for this would increase the self-induction of
    the former, and lengthen the discharge path in the latter.
    Increasing the self-induction of the primary reduces the E. M. F.
    induced in the secondary, whilst lengthening the secondary does not
    increase the E. M. F. per unit length. The two or three turns, as
    shown in Fig. 216, in each, were found to be quite sufficient, and,
    on discharging the Leyden jar between two highly polished knobs in
    the primary circuit, a plain uniform band of light was seen to pass
    round the secondary. An exhausted bulb, Fig. 217, containing traces
    of oxygen was placed within a primary spiral of three turns, and,
    on passing the jar discharge, a circle of light was seen within the
    bulb in close proximity to the primary circuit, accompanied by a
    purplish glow, which lasted for a second or more. On heating the
    bulb, the duration of the glow was greatly diminished, and it could
    be instantly extinguished by the presence of an electro-magnet.
    Another exhausted bulb, Fig. 218, surrounded by a primary spiral,
    was contained in a bell-jar, and when the pressure of air in the
    jar was about that of the atmosphere, the secondary discharge
    occurred in the bulb, as is ordinarily the case. On exhausting the
    jar, however, the luminous discharge grew fainter, and a point was
    reached at which no secondary discharge was visible. Further
    exhaustion of the jar caused the secondary discharge to appear
    outside of the bulb. The fact of obtaining no luminous discharge,
    either in the bulb or jar, the author could only explain on two
    suppositions, viz.: that under the conditions then existing the
    specific inductive capacity of the gas was very great, or that a
    discharge could pass without being luminous. The author had also
    observed that the conductivity of a vacuum tube without electrodes
    increased as the pressure diminished, until a certain point was
    reached, and afterwards diminished again, thus showing that the
    high resistance of a nearly perfect vacuum is in no way due to the
    presence of the electrodes. One peculiarity of the discharges was
    their local nature, the rings of light being much more sharply
    defined than was to be expected. They were also found to be most
    easily produced when the chain of molecules in the discharge were
    all of the same kind. For example, a discharge could be easily sent
    through a tube many feet long, but the introduction of a small
    pellet of mercury in the tube stopped the discharge, although the
    conductivity of the mercury was much greater than that of the
    vacuum. In some cases he had noticed that a very fine wire placed
    within a tube, on the side remote from the primary circuit, would
    prevent a luminous discharge in that tube.

    Fig. 219 shows an exhausted secondary coil of one loop containing
    bulbs; the discharge passed along the inner side of the bulbs, the
    primary coils being placed within the secondary.


[9]In _The Electrical Engineer_ of August 12, I find some remarks of
Prof. J. J. Thomson, which appeared originally in the London
_Electrician_ and which have a bearing upon some experiments described
by me in your issue of July 1.

  [9] Article by Mr. Tesla in _The Electrical Engineer_, N. Y.,
      August 26, 1891.

I did not, as Prof. J. J. Thomson seems to believe, misunderstand his
position in regard to the cause of the phenomena considered, but I
thought that in his experiments, as well as in my own, electrostatic
effects were of great importance. It did not appear, from the meagre
description of his experiments, that all possible precautions had been
taken to exclude these effects. I did not doubt that luminosity could be
excited in a closed tube when electrostatic action is completely
excluded. In fact, at the outset, I myself looked for a purely
electrodynamic effect and believed that I had obtained it. But many
experiments performed at that time proved to me that the electrostatic
effects were generally of far greater importance, and admitted of a more
satisfactory explanation of most of the phenomena observed.

In using the term _electrostatic_ I had reference rather to the nature
of the action than to a stationary condition, which is the usual
acceptance of the term. To express myself more clearly, I will suppose
that near a closed exhausted tube be placed a small sphere charged to a
very high potential. The sphere would act inductively upon the tube, and
by distributing electricity over the same would undoubtedly produce
luminosity (if the potential be sufficiently high), until a permanent
condition would be reached. Assuming the tube to be perfectly well
insulated, there would be only one instantaneous flash during the act of
distribution. This would be due to the electrostatic action simply.

But now, suppose the charged sphere to be moved at short intervals with
great speed along the exhausted tube. The tube would now be permanently
excited, as the moving sphere would cause a constant redistribution of
electricity and collisions of the molecules of the rarefied gas. We
would still have to deal with an electrostatic effect, and in addition
an electrodynamic effect would be observed. But if it were found that,
for instance, the effect produced depended more on the specific
inductive capacity than on the magnetic permeability of the
medium--which would certainly be the case for speeds incomparably lower
than that of light--then I believe I would be justified in saying that
the effect produced was more of an electrostatic nature. I do not mean
to say, however, that any similar condition prevails in the case of the
discharge of a Leyden jar through the primary, but I think that such an
action would be desirable.

It is in the spirit of the above example that I used the terms "more of
an electrostatic nature," and have investigated the influence of bodies
of high specific inductive capacity, and observed, for instance, the
importance of the quality of glass of which the tube is made. I also
endeavored to ascertain the influence of a medium of high permeability
by using oxygen. It appeared from rough estimation that an oxygen tube
when excited under similar conditions--that is, as far as could be
determined--gives more light; but this, of course, may be due to many
causes.

Without doubting in the least that, with the care and precautions taken
by Prof. J. J. Thomson, the luminosity excited was due solely to
electrodynamic action, I would say that in many experiments I have
observed curious instances of the ineffectiveness of the screening, and
I have also found that the electrification through the air is often of
very great importance, and may, in some cases, determine the excitation
of the tube.

In his original communication to the _Electrician_, Prof. J. J. Thomson
refers to the fact that the luminosity in a tube near a wire through
which a Leyden jar was discharged was noted by Hittorf. I think that the
feeble luminous effect referred to has been noted by many
experimenters, but in my experiments the effects were much more powerful
than those usually noted.

The following is the communication[10] referred to:--

  [10] Note by Prof. J. J. Thomson in the London _Electrician_,
       July 24, 1891.

    "Mr. Tesla seems to ascribe the effects he observed to
    electrostatic action, and I have no doubt, from the description he
    gives of his method of conducting his experiments, that in them
    electrostatic action plays a very important part. He seems,
    however, to have misunderstood my position with respect to the
    cause of these discharges, which is not, as he implies, that
    luminosity in tubes without electrodes cannot be produced by
    electrostatic action, but that it can also be produced when this
    action is excluded. As a matter of fact, it is very much easier to
    get the luminosity when these electrostatic effects are operative
    than when they are not. As an illustration of this I may mention
    that the first experiment I tried with the discharge of a Leyden
    jar produced luminosity in the tube, but it was not until after six
    weeks' continuous experimenting that I was able to get a discharge
    in the exhausted tube which I was satisfied was due to what is
    ordinarily called electrodynamic action. It is advisable to have a
    clear idea of what we mean by electrostatic action. If, previous to
    the discharge of the jar, the primary coil is raised to a high
    potential, it will induce over the glass of the tube a distribution
    of electricity. When the potential of the primary suddenly falls,
    this electrification will redistribute itself, and may pass through
    the rarefied gas and produce luminosity in doing so. Whilst the
    discharge of the jar is going on, it is difficult, and, from a
    theoretical point of view, undesirable, to separate the effect into
    parts, one of which is called electrostatic, the other
    electromagnetic; what we can prove is that in this case the
    discharge is not such as would be produced by electromotive forces
    derived from a potential function. In my experiments the primary
    coil was connected to earth, and, as a further precaution, the
    primary was separated from the discharge tube by a screen of
    blotting paper, moistened with dilute sulphuric acid, and connected
    to earth. Wet blotting paper is a sufficiently good conductor to
    screen off a stationary electrostatic effect, though it is not a
    good enough one to stop waves of alternating electromotive
    intensity. When showing the experiments to the Physical Society I
    could not, of course, keep the tubes covered up, but, unless my
    memory deceives me, I stated the precautions which had been taken
    against the electrostatic effect. To correct misapprehension I may
    state that I did not read a formal paper to the Society, my object
    being to exhibit a few of the most typical experiments. The account
    of the experiments in the _Electrician_ was from a reporter's note,
    and was not written, or even read, by me. I have now almost
    finished writing out, and hope very shortly to publish, an account
    of these and a large number of allied experiments, including some
    analogous to those mentioned by Mr. Tesla on the effect of
    conductors placed near the discharge tube, which I find, in some
    cases, to produce a diminution, in others an increase, in the
    brightness of the discharge, as well as some on the effect of the
    presence of substances of large specific inductive capacity. These
    seem to me to admit of a satisfactory explanation, for which,
    however, I must refer to my paper."




PART III.

MISCELLANEOUS INVENTIONS AND WRITINGS.




CHAPTER XXXIII.

METHOD OF OBTAINING DRIECT FROM ALTERNATING CURRENTS.


This method consists in obtaining direct from alternating currents, or
in directing the waves of an alternating current so as to produce direct
or substantially direct currents by developing or producing in the
branches of a circuit including a source of alternating currents, either
permanently or periodically, and by electric, electro-magnetic, or
magnetic agencies, manifestations of energy, or what may be termed
active resistances of opposite electrical character, whereby the
currents or current waves of opposite sign will be diverted through
different circuits, those of one sign passing over one branch and those
of opposite sign over the other.

We may consider herein only the case of a circuit divided into two
paths, inasmuch as any further subdivision involves merely an extension
of the general principle. Selecting, then, any circuit through which is
flowing an alternating current, Mr. Tesla divides such circuit at any
desired point into two branches or paths. In one of these paths he
inserts some device to create an electromotive force counter to the
waves or impulses of current of one sign and a similar device in the
other branch which opposes the waves of opposite sign. Assume, for
example, that these devices are batteries, primary or secondary, or
continuous current dynamo machines. The waves or impulses of opposite
direction composing the main current have a natural tendency to divide
between the two branches; but by reason of the opposite electrical
character or effect of the two branches, one will offer an easy passage
to a current of a certain direction, while the other will offer a
relatively high resistance to the passage of the same current. The
result of this disposition is, that the waves of current of one sign
will, partly or wholly, pass over one of the paths or branches, while
those of the opposite sign pass over the other. There may thus be
obtained from an alternating current two or more direct currents without
the employment of any commutator such as it has been heretofore
regarded as necessary to use. The current in either branch may be
used in the same way and for the same purposes as any other direct
current--that is, it may be made to charge secondary batteries, energize
electro-magnets, or for any other analogous purpose.

Fig. 220 represents a plan of directing the alternating currents by
means of devices purely electrical in character. Figs. 221, 222, 223,
224, 225, and 226 are diagrams illustrative of other ways of carrying
out the invention.

[Illustration: FIG. 220.]

In Fig. 220, A designates a generator of alternating currents, and B B
the main or line circuit therefrom. At any given point in this circuit
at or near which it is desired to obtain direct currents, the circuit B
is divided into two paths or branches C D. In each of these branches is
placed an electrical generator, which for the present we will assume
produces direct or continuous currents. The direction of the current
thus produced is opposite in one branch to that of the current in the
other branch, or, considering the two branches as forming a closed
circuit, the generators E F are connected up in series therein, one
generator in each part or half of the circuit. The electromotive force
of the current sources E and F may be equal to or higher or lower than
the electromotive forces in the branches C D, or between the points X
and Y of the circuit B B. If equal, it is evident that current waves of
one sign will be opposed in one branch and assisted in the other to such
an extent that all the waves of one sign will pass over one branch and
those of opposite sign over the other. If, on the other hand, the
electromotive force of the sources E F be lower than that between X and
Y, the currents in both branches will be alternating, but the waves of
one sign will preponderate. One of the generators or sources of current
E or F may be dispensed with; but it is preferable to employ both, if
they offer an appreciable resistance, as the two branches will be
thereby better balanced. The translating or other devices to be acted
upon by the current are designated by the letters G, and they are
inserted in the branches C D in any desired manner; but in order to
better preserve an even balance between the branches due regard should,
of course, be had to the number and character of the devices.

[Illustration: FIG. 221.]

Figs. 221, 222, 223, and 224 illustrate what may termed
"electro-magnetic" devices for accomplishing a similar result--that is
to say, instead of producing directly by a generator an electromotive
force in each branch of the circuit, Mr. Tesla establishes a field or
fields of force and leads the branches through the same in such manner
that an active opposition of opposite effect or direction will be
developed therein by the passage, or tendency to pass, of the
alternations of current. In Fig. 221, for example, A is the generator of
alternating currents, B B the line circuit, and C D the branches over
which the alternating currents are directed. In each branch is included
the secondary of a transformer or induction coil, which, since they
correspond in their functions to the batteries of the previous figure,
are designated by the letters E F. The primaries H H' of the induction
coils or transformers are connected either in parallel or series with a
source of direct or continuous currents I, and the number of
convolutions is so calculated for the strength of the current from I
that the cores J J' will be saturated. The connections are such that the
conditions in the two transformers are of opposite character--that is to
say, the arrangement is such that a current wave or impulse
corresponding in direction with that of the direct current in one
primary, as H, is of opposite direction to that in the other primary H'.
It thus results that while one secondary offers a resistance or
opposition to the passage through it of a wave of one sign, the other
secondary similarly opposes a wave of opposite sign. In consequence, the
waves of one sign will, to a greater or less extent, pass by way of one
branch, while those of opposite sign in like manner pass over the other
branch.

In lieu of saturating the primaries by a source of continuous current,
we may include the primaries in the branches C D, respectively, and
periodically short-circuit by any suitable mechanical devices--such as
an ordinary revolving commutator--their secondaries. It will be
understood, of course, that the rotation and action of the commutator
must be in synchronism or in proper accord with the periods of the
alternations in order to secure the desired results. Such a disposition
is represented diagrammatically in Fig. 222. Corresponding to the
previous figures, A is the generator of alternating currents, B B the
line, and C D the two branches for the direct currents. In branch C are
included two primary coils E E', and in branch D are two similar
primaries F F' The corresponding secondaries for these coils and which
are on the same subdivided cores J or J', are in circuits the terminals
of which connect to opposite segments K K', and L L', respectively, of a
commutator. Brushes _b b_ bear upon the commutator and alternately
short-circuit the plates K and K', and L and L', through a connection
_c_. It is obvious that either the magnets and commutator, or the
brushes, may revolve.

[Illustration: FIG. 222.]

The operation will be understood from a consideration of the effects of
closing or short-circuiting the secondaries. For example, if at the
instant when a given wave of current passes, one set of secondaries be
short-circuited, nearly all the current flows through the corresponding
primaries; but the secondaries of the other branch being open-circuited,
the self-induction in the primaries is highest, and hence little or no
current will pass through that branch. If, as the current alternates,
the secondaries of the two branches are alternately short-circuited, the
result will be that the currents of one sign pass over one branch and
those of the opposite sign over the other. The disadvantages of this
arrangement, which would seem to result from the employment of sliding
contacts, are in reality very slight, inasmuch as the electromotive
force of the secondaries may be made exceedingly low, so that sparking
at the brushes is avoided.

[Illustration: FIG. 223.]

Fig. 223 is a diagram, partly in section, of another plan of carrying
out the invention. The circuit B in this case is divided, as before, and
each branch includes the coils of both the fields and revolving
armatures of two induction devices. The armatures O P are preferably
mounted on the same shaft, and are adjusted relatively to one another in
such manner that when the self-induction in one branch, as C, is
maximum, in the other branch D it is minimum. The armatures are rotated
in synchronism with the alternations from the source A. The winding or
position of the armature coils is such that a current in a given
direction passed through both armatures would establish in one, poles
similar to those in the adjacent poles of the field, and in the other,
poles unlike the adjacent field poles, as indicated by _n n s s_ in the
diagram. If the like poles are presented, as shown in circuit D, the
condition is that of a closed secondary upon a primary, or the position
of least inductive resistance; hence a given alternation of current will
pass mainly through D. A half revolution of the armatures produces an
opposite effect and the succeeding current impulse passes through C.
Using this figure as an illustration, it is evident that the fields N M
may be permanent magnets or independently excited and the armatures O P
driven, as in the present case, so as to produce alternate currents,
which will set up alternately impulses of opposite direction in the two
branches D C, which in such case would include the armature circuits and
translating devices only.

In Fig. 224 a plan alternative with that shown in Fig. 222 is
illustrated. In the previous case illustrated, each branch C and D
contained one or more primary coils, the secondaries of which were
periodically short circuited in synchronism with the alternations of
current from the main source A, and for this purpose a commutator was
employed. The latter may, however, be dispensed with and an armature
with a closed coil substituted.

[Illustration: FIG. 224.]

Referring to Fig. 224 in one of the branches, as C, are two coils M',
wound on laminated cores, and in the other branches D are similar coils
N'. A subdivided or laminated armature O', carrying a closed coil R', is
rotatably supported between the coils M' N', as shown. In the position
shown--that is, with the coil R' parallel with the convolutions of the
primaries N' M'--practically the whole current will pass through branch
D, because the self-induction in coils M' M' is maximum. If, therefore,
the armature and coil be rotated at a proper speed relatively to the
periods or alternations of the source A, the same results are obtained
as in the case of Fig. 222.

Fig. 225 is an instance of what may be called, in distinction to the
others, a "magnetic" means of securing the result. V and W are two
strong permanent magnets provided with armatures V' W', respectively.
The armatures are made of thin laminae of soft iron or steel, and the
amount of magnetic metal which they contain is so calculated that they
will be fully or nearly saturated by the magnets. Around the armatures
are coils E F, contained, respectively, in the circuits C and D. The
connections and electrical conditions in this case are similar to those
in Fig. 221, except that the current source of I, Fig. 221, is dispensed
with and the saturation of the core of coils E F obtained from the
permanent magnets.

[Illustration: FIG. 225.]

The previous illustrations have all shown the two branches or paths
containing the translating or induction devices as in derivation one to
the other; but this is not always necessary. For example, in Fig. 226, A
is an alternating-current generator; B B, the line wires or circuit. At
any given point in the circuit let us form two paths, as D D', and at
another point two paths, as C C'. Either pair or group of paths is
similar to the previous dispositions with the electrical source or
induction device in one branch only, while the two groups taken together
form the obvious equivalent of the cases in which an induction device or
generator is included in both branches. In one of the paths, as D, are
included the devices to be operated by the current. In the other branch,
as D', is an induction device that opposes the current impulses of one
direction and directs them through the branch D. So, also, in branch C
are translating devices G, and in branch C' an induction device or its
equivalent that diverts through C impulses of opposite direction to
those diverted by the device in branch D'. The diagram shows a special
form of induction device for this purpose. J J' are the cores, formed
with pole-pieces, upon which are wound the coils M N. Between these
pole-pieces are mounted at right angles to one another the magnetic
armatures O P, preferably mounted on the same shaft and designed to be
rotated in synchronism with the alternations of current. When one of the
armatures is in line with the poles or in the position occupied by
armature P, the magnetic circuit of the induction device is practically
closed; hence there will be the greatest opposition to the passage of a
current through coils N N. The alternation will therefore pass by way of
branch D. At the same time, the magnetic circuit of the other induction
device being broken by the position of the armature O, there will be
less opposition to the current in coils M, which will shunt the current
from branch C. A reversal of the current being attended by a shifting of
the armatures, the opposite effect is produced.

[Illustration: FIG. 226.]

Other modifications of these methods are possible, but need not be
pointed out. In all these plans, it will be observed, there is developed
in one or all of these branches of a circuit from a source of
alternating currents, an active (as distinguished from a dead)
resistance or opposition to the currents of one sign, for the purpose of
diverting the currents of that sign through the other or another path,
but permitting the currents of opposite sign to pass without substantial
opposition.

Whether the division of the currents or waves of current of opposite
sign be effected with absolute precision or not is immaterial, since it
will be sufficient if the waves are only partially diverted or directed,
for in such case the preponderating influence in each branch of the
circuit of the waves of one sign secures the same practical results in
many if not all respects as though the current were direct and
continuous.

An alternating and a direct current have been combined so that the waves
of one direction or sign were partially or wholly overcome by the direct
current; but by this plan only one set of alternations are utilized,
whereas by the system just described the entire current is rendered
available. By obvious applications of this discovery Mr. Tesla is
enabled to produce a self-exciting alternating dynamo, or to operate
direct current meters on alternating-current circuits or to run various
devices--such as arc lamps--by direct currents in the same circuit with
incandescent lamps or other devices operated by alternating currents.

It will be observed that if an intermittent counter or opposing force be
developed in the branches of the circuit and of higher electromotive
force than that of the generator, an alternating current will result in
each branch, with the waves of one sign preponderating, while a
constantly or uniformly acting opposition in the branches of higher
electromotive force than the generator would produce a pulsating
current, which conditions would be, under some circumstances, the
equivalent of those described.




CHAPTER XXXIV.

CONDENSERS WITH PLATES IN OIL.


[Illustration: FIG. 227.]

[Illustration: FIG. 228.]

In experimenting with currents of high frequency and high potential, Mr.
Tesla has found that insulating materials such as glass, mica, and in
general those bodies which possess the highest specific inductive
capacity, are inferior as insulators in such devices when currents of
the kind described are employed compared with those possessing high
insulating power, together with a smaller specific inductive capacity;
and he has also found that it is very desirable to exclude all gaseous
matter from the apparatus, or any access of the same to the electrified
surfaces, in order to prevent heating by molecular bombardment and the
loss or injury consequent thereon. He has therefore devised a method to
accomplish these results and produce highly efficient and reliable
condensers, by using oil as the dielectric[11]. The plan admits of a
particular construction of condenser, in which the distance between the
plates is adjustable, and of which he takes advantage.

  [11] Mr. Tesla's experiments, as the careful reader of his three
    lectures will perceive, have revealed a very important fact which
    is taken advantage of in this invention. Namely, he has shown that
    in a condenser a considerable amount of energy may be wasted, and
    the condenser may break down merely because gaseous matter is
    present between the surfaces. A number of experiments are described
    in the lectures, which bring out this fact forcibly and serve as a
    guide in the operation of high tension apparatus. But besides
    bearing upon this point, these experiments also throw a light upon
    investigations of a purely scientific nature and explain now the
    lack of harmony among the observations of various investigators.
    Mr. Tesla shows that in a fluid such as oil the losses are very
    small as compared with those incurred in a gas.

In the accompanying illustrations, Fig. 227 is a section of a condenser
constructed in accordance with this principle and having stationary
plates; and Fig. 228 is a similar view of a condenser with adjustable
plates.

Any suitable box or receptacle A may be used to contain the plates or
armatures. These latter are designated by B and C and are connected,
respectively, to terminals D and E, which pass out through the sides of
the case. The plates ordinarily are separated by strips of porous
insulating material F, which are used merely for the purpose of
maintaining them in position. The space within the can is filled with
oil G. Such a condenser will prove highly efficient and will not become
heated or permanently injured.

In many cases it is desirable to vary or adjust the capacity of a
condenser, and this is provided for by securing the plates to adjustable
supports--as, for example, to rods H--passing through stuffing boxes K
in the sides of case A and furnished with nuts L, the ends of the rods
being threaded for engagement with the nuts.

It is well known that oils possess insulating properties, and it has
been a common practice to interpose a body of oil between two conductors
for purposes of insulation; but Mr. Tesla believes he has discovered
peculiar properties in oils which render them very valuable in this
particular form of device.




CHAPTER XXXV.

ELECTROLYTIC REGISTERING METER.


An ingenious form of electrolytic meter attributable to Mr. Tesla is one
in which a conductor is immersed in a solution, so arranged that metal
may be deposited from the solution or taken away in such a manner that
the electrical resistance of the conductor is varied in a definite
proportion to the strength of the current the energy of which is to be
computed, whereby this variation in resistance serves as a measure of
the energy and also may actuate registering mechanism, whenever the
resistance rises above or falls below certain limits.

In carrying out this idea Mr. Tesla employs an electrolytic cell,
through which extend two conductors parallel and in close proximity to
each other. These conductors he connects in series through a resistance,
but in such manner that there is an equal difference of potential
between them throughout their entire extent. The free ends or terminals
of the conductors are connected either in series in the circuit
supplying the current to the lamps or other devices, or in parallel to a
resistance in the circuit and in series with the current consuming
devices. Under such circumstances a current passing through the
conductors establishes a difference of potential between them which is
proportional to the strength of the current, in consequence of which
there is a leakage of current from one conductor to the other across the
solution. The strength of this leakage current is proportional to the
difference of potential, and, therefore, in proportion to the strength
of the current passing through the conductors. Moreover, as there is a
constant difference of potential between the two conductors throughout
the entire extent that is exposed to the solution, the current density
through such solution is the same at all corresponding points, and hence
the deposit is uniform along the whole of one of the conductors, while
the metal is taken away uniformly from the other. The resistance of one
conductor is by this means diminished, while that of the other is
increased, both in proportion to the strength of the current passing
through the conductors. From such variation in the resistance of either
or both of the conductors forming the positive and negative electrodes
of the cell, the current energy expended may be readily computed. Figs.
229 and 230 illustrate two forms of such a meter.

[Illustration: FIG. 229.]

In Fig. 229 G designates a direct-current generator. L L are the
conductors of the circuit extending therefrom. A is a tube of glass, the
ends of which are sealed, as by means of insulating plugs or caps B B. C
C' are two conductors extending through the tube A, their ends passing
out through the plugs B to terminals thereon. These conductors may be
corrugated or formed in other proper ways to offer the desired
electrical resistance. R is a resistance connected in series with the
two conductors C C', which by their free terminals are connected up in
circuit with one of the conductors L.

The method of using this device and computing by means thereof the
energy of the current will be readily understood. First, the resistances
of the two conductors C C', respectively, are accurately measured and
noted. Then a known current is passed through the instrument for a given
time, and by a second measurement the increase and diminution of the
resistances of the two conductors are respectively taken. From these
data the constant is obtained--that is to say, for example, the
increase of resistance of one conductor or the diminution of the
resistance of the other per lamp hour. These two measurements evidently
serve as a check, since the gain of one conductor should equal the loss
of the other. A further check is afforded by measuring both wires in
series with the resistance, in which case the resistance of the whole
should remain constant.

[Illustration: FIG. 230.]

In Fig. 230 the conductors C C' are connected in parallel, the current
device at X passing in one branch first through a resistance R' and then
through conductor C, while on the other branch it passes first through
conductor C', and then through resistance R''. The resistances R' R''
are equal, as also are the resistances of the conductors C C'. It is,
moreover, preferable that the respective resistances of the conductors C
C' should be a known and convenient fraction of the coils or resistances
R' R''. It will be observed that in the arrangement shown in Fig. 230
there is a constant potential difference between the two conductors C C'
throughout their entire length.

It will be seen that in both cases illustrated, the proportionality of
the increase or decrease of resistance to the current strength will
always be preserved, for what one conductor gains the other loses, and
the resistances of the conductors C C' being small as compared with the
resistances in series with them. It will be understood that after each
measurement or registration of a given variation of resistance in one or
both conductors, the direction of the current should be changed or the
instrument reversed, so that the deposit will be taken from the
conductor which has gained and added to that which has lost. This
principle is capable of many modifications. For instance, since there is
a section of the circuit--to wit, the conductor C or C'--that varies in
resistance in proportion to the current strength, such variation may be
utilized, as is done in many analogous cases, to effect the operation of
various automatic devices, such as registers. It is better, however, for
the sake of simplicity to compute the energy by measurements of
resistance.

The chief advantages of this arrangement are, first, that it is possible
to read off directly the amount of the energy expended by means of a
properly constructed ohm-meter and without resorting to weighing the
deposit; secondly it is not necessary to employ shunts, for the whole of
the current to be measured may be passed through the instrument; third,
the accuracy of the instrument and correctness of the indications are
but slightly affected by changes in temperature. It is also said that
such meters have the merit of superior economy and compactness, as well
as of cheapness in construction. Electrolytic meters seem to need every
auxiliary advantage to make them permanently popular and successful, no
matter how much ingenuity may be shown in their design.




CHAPTER XXXVI.

THERMO-MAGNETIC MOTORS AND PYRO-MAGNETIC GENERATORS.


No electrical inventor of the present day dealing with the problems of
light and power considers that he has done himself or his opportunities
justice until he has attacked the subject of thermo-magnetism. As far
back as the beginning of the seventeenth century it was shown by Dr.
William Gilbert, the father of modern electricity, that a loadstone or
iron bar when heated to redness loses its magnetism; and since that time
the influence of heat on the magnetic metals has been investigated
frequently, though not with any material or practical result.

For a man of Mr. Tesla's inventive ability, the problems in this field
have naturally had no small fascination, and though he has but glanced
at them, it is to be hoped he may find time to pursue the study deeper
and further. For such as he, the investigation must undoubtedly bear
fruit. Meanwhile he has worked out one or two operative devices worthy
of note.[12] He obtains mechanical power by a reciprocating action
resulting from the joint operations of heat, magnetism, and a spring or
weight or other force--that is to say he subjects a body magnetized by
induction or otherwise to the action of heat until the magnetism is
sufficiently neutralized to allow a weight or spring to give motion to
the body and lessen the action of the heat, so that the magnetism may be
sufficiently restored to move the body in the opposite direction, and
again subject the same to the demagnetizing power of the heat.

  [12] It will, of course, be inferred from the nature of these devices
       that the vibration obtained in this manner is very slow owing to
       the inability of the iron to follow rapid changes in temperature.
       In an interview with Mr. Tesla on this subject, the compiler
       learned of an experiment which will interest students. A simple
       horseshoe magnet is taken and a piece of sheet iron bent in the
       form of an L is brought in contact with one of the poles and
       placed in such a position that it is kept in the attraction of
       the opposite pole delicately suspended. A spirit lamp is placed
       under the sheet iron piece and when the iron is heated to a
       certain temperature it is easily set in vibration oscillating
       as rapidly as 400 to 500 times a minute. The experiment is very
       easily performed and is interesting principally on account of the
       very rapid rate of vibration.

Use is made of either an electro-magnet or a permanent magnet, and the
heat is directed against a body that is magnetized by induction, rather
than directly against a permanent magnet, thereby avoiding the loss of
magnetism that might result in the permanent magnet by the action of
heat. Mr. Tesla also provides for lessening the volume of the heat or
for intercepting the same during that portion of the reciprocation in
which the cooling action takes place.

In the diagrams are shown some of the numerous arrangements that may be
made use of in carrying out this idea. In all of these figures the
magnet-poles are marked N S, the armature A, the Bunsen burner or other
source of heat H, the axis of motion M, and the spring or the equivalent
thereof--namely, a weight--is marked W.

[Illustration: FIG. 232.]

[Illustration: FIG. 231.]

[Illustration: FIG. 233.]


In Fig. 231 the permanent magnet N is connected with a frame, F,
supporting the axis M, from which the arm P hangs, and at the lower end
of which the armature A is supported. The stops 2 and 3 limit the extent
of motion, and the spring W tends to draw the armature A away from the
magnet N. It will now be understood that the magnetism of N is
sufficient to overcome the spring W and draw the armature A toward the
magnet N. The heat acting upon the armature A neutralizes its induced
magnetism sufficiently for the spring W to draw the armature A away from
the magnet N and also from the heat at H. The armature now cools, and
the attraction of the magnet N overcomes the spring W and draws the
armature A back again above the burner H, so that the same is again
heated and the operations are repeated. The reciprocating movements thus
obtained are employed as a source of mechanical power in any desired
manner. Usually a connecting-rod to a crank upon a fly-wheel shaft would
be made use of, as indicated in Fig. 240.

[Illustration: FIG. 234.]

[Illustration: FIG. 236.]

[Illustration: FIG. 235.]

Fig. 232 represents the same parts as before described; but an
electro-magnet is illustrated in place of a permanent magnet. The
operations, however, are the same.

In Fig. 233 are shown the same parts as in Figs. 231 and 232, but they
are differently arranged. The armature A, instead of swinging, is
stationary and held by arm P', and the core N S of the electro-magnet is
made to swing within the helix Q, the core being suspended by the arm P
from the pivot M. A shield, R, is connected with the magnet-core and
swings with it, so that after the heat has demagnetized the armature A
to such an extent that the spring W draws the core N S away from the
armature A, the shield R comes between the flame H and armature A,
thereby intercepting the action of the heat and allowing the armature to
cool, so that the magnetism, again preponderating, causes the movement
of the core N S toward the armature A and the removal of the shield R
from above the flame, so that the heat again acts to lessen or
neutralize the magnetism. A rotary or other movement may be obtained
from this reciprocation.

Fig. 234 corresponds in every respect with Fig. 233, except that a
permanent horseshoe-magnet, N S is represented as taking the place of
the electro-magnet in Fig. 233.

In Fig. 235 is shown a helix, Q, with an armature adapted to swing
toward or from the helix. In this case there may be a soft-iron core in
the helix, or the armature may assume the form of a solenoid core, there
being no permanent core within the helix.

[Illustration: FIG. 237.]

[Illustration: FIG. 238.]

[Illustration: FIG. 239.]


Fig. 236 is an end view, and Fig. 237 a plan view, illustrating the
method as applied to a swinging armature, A, and a stationary permanent
magnet, N S. In this instance Mr. Tesla applies the heat to an auxiliary
armature or keeper, T, which is adjacent to and preferably in direct
contact with the magnet. This armature T, in the form of a plate of
sheet-iron, extends across from one pole to the other and is of
sufficient section to practically form a keeper for the magnet, so that
when the armature T is cool nearly all the lines of force pass over the
same and very little free magnetism is exhibited. Then the armature A,
which swings freely on the pivots M in front of the poles N S, is very
little attracted and the spring W pulls the same way from the poles into
the position indicated in the diagram. The heat is directed upon the
iron plate T at some distance from the magnet, so as to allow the magnet
to keep comparatively cool. This heat is applied beneath the plate by
means of the burners H, and there is a connection from the armature A or
its pivot to the gas-cock 6, or other device for regulating the heat.
The heat acting upon the middle portion of the plate T, the magnetic
conductivity of the heated portion is diminished or destroyed, and a
great number of the lines of force are deflected over the armature A,
which is now powerfully attracted and drawn into line, or nearly so,
with the poles N S. In so doing the cock 6 is nearly closed and the
plate T cools, the lines of force are again deflected over the same, the
attraction exerted upon the armature A is diminished, and the spring W
pulls the same away from the magnet into the position shown by full
lines, and the operations are repeated. The arrangement shown in Fig.
236 has the advantages that the magnet and armature are kept cool and
the strength of the permanent magnet is better preserved, as the
magnetic circuit is constantly closed.

In the plan view, Fig. 238, is shown a permanent magnet and keeper
plate, T, similar to those in Figs. 236 and 237, with the burners H for
the gas beneath the same; but the armature is pivoted at one end to one
pole of the magnet and the other end swings toward and from the other
pole of the magnet. The spring W acts against a lever arm that projects
from the armature, and the supply of heat has to be partly cut off by a
connection to the swinging armature, so as to lessen the heat acting
upon the keeper plate when the armature A has been attracted.

[Illustration: FIG. 240.]

[Illustration: FIG. 241.]

Fig. 239 is similar to Fig. 238, except that the keeper T is not made
use of and the armature itself swings into and out of the range of the
intense action of the heat from the burner H. Fig. 240 is a diagram
similar to Fig. 231, except that in place of using a spring and stops,
the armature is shown as connected by a link, to the crank of a
fly-wheel, so that the fly-wheel will be revolved as rapidly as the
armature can be heated and cooled to the necessary extent. A spring may
be used in addition, as in Fig. 231. In Fig. 241 the armatures A A are
connected by a link, so that one will be heating while the other is
cooling, and the attraction exerted to move the cooled armature is
availed of to draw away the heated armature instead of using a spring.

Mr. Tesla has also devoted his attention to the development of a
pyromagnetic generator of electricity[13] based upon the following laws:
First, that electricity or electrical energy is developed in any
conducting body by subjecting such body to a varying magnetic influence;
and second, that the magnetic properties of iron or other magnetic
substance may be partially or entirely destroyed or caused to disappear
by raising it to a certain temperature, but restored and caused to
reappear by again lowering its temperature to a certain degree. These
laws may be applied in the production of electrical currents in many
ways, the principle of which is in all cases the same, viz., to subject
a conductor to a varying magnetic influence, producing such variations
by the application of heat, or, more strictly speaking, by the
application or action of a varying temperature upon the source of the
magnetism. This principle of operation may be illustrated by a simple
experiment: Place end to end, and preferably in actual contact, a
permanently magnetized steel bar and a strip or bar of soft iron. Around
the end of the iron bar or plate wind a coil of insulated wire. Then
apply to the iron between the coil and the steel bar a flame or other
source of heat which will be capable of raising that portion of the iron
to an orange red, or a temperature of about 600 deg. centigrade. When this
condition is reached, the iron somewhat suddenly loses its magnetic
properties, if it be very thin, and the same effect is produced as
though the iron had been moved away from the magnet or the heated
section had been removed. This change of position, however, is
accompanied by a shifting of the magnetic lines, or, in other words, by
a variation in the magnetic influence to which the coil is exposed, and
a current in the coil is the result. Then remove the flame or in any
other way reduce the temperature of the iron. The lowering of its
temperature is accompanied by a return of its magnetic properties, and
another change of magnetic conditions occurs, accompanied by a current
in an opposite direction in the coil. The same operation may be
repeated indefinitely, the effect upon the coil being similar to that
which would follow from moving the magnetized bar to and from the end of
the iron bar or plate.

  [13] The chief point to be noted is that Mr. Tesla attacked this
       problem in a way which was, from the standpoint of theory, and
       that of an engineer, far better than that from which some
       earlier trials in this direction started. The enlargement of
       these ideas will be found in Mr. Tesla's work on the pyromagnetic
       generator, treated in this chapter. The chief effort of the
       inventor was to economize the heat, which was accomplished by
       inclosing the iron in a source of heat well insulated, and by
       cooling the iron by means of steam, utilizing the steam over
       again. The construction also permits of more rapid magnetic
       changes per unit of time, meaning larger output.

The device illustrated below is a means of obtaining this result, the
features of novelty in the invention being, first, the employment of an
artificial cooling device, and, second, inclosing the source of heat and
that portion of the magnetic circuit exposed to the heat and
artificially cooling the heated part.

These improvements are applicable generally to the generators
constructed on the plan above described--that is to say, we may use an
artificial cooling device in conjunction with a variable or varied or
uniform source of heat.

[Illustration: FIG. 242.]

[Illustration: FIG. 243.]

Fig. 242 is a central vertical longitudinal section of the complete
apparatus and Fig. 243 is a cross-section of the magnetic armature-core
of the generator.

Let A represent a magnetized core or permanent magnet the poles of which
are bridged by an armature-core composed of a casing or shell B
inclosing a number of hollow iron tubes C. Around this core are wound
the conductors E E', to form the coils in which the currents are
developed. In the circuits of these coils are current-consuming devices,
as F F'.

D is a furnace or closed fire-box, through which the central portion of
the core B extends. Above the fire is a boiler K, containing water. The
flue L from the fire-box may extend up through the boiler.

G is a water-supply pipe, and H is the steam-exhaust pipe, which
communicates with all the tubes C in the armature B, so that steam
escaping from the boiler will pass through the tubes.

In the steam-exhaust pipe H is a valve V, to which is connected the
lever I, by the movement of which the valve is opened or closed. In such
a case as this the heat of the fire may be utilized for other purposes
after as much of it as may be needed has been applied to heating the
core B. There are special advantages in the employment of a cooling
device, in that the metal of the core B is not so quickly oxidized.
Moreover, the difference between the temperature of the applied heat and
of the steam, air, or whatever gas or fluid be applied as the cooling
medium, may be increased or decreased at will, whereby the rapidity of
the magnetic changes or fluctuations may be regulated.




CHAPTER XXXVII.

ANTI-SPARKING DYNAMO BRUSH AND COMMUTATOR.


In direct current dynamos of great electromotive force--such, for
instance, as those used for arc lighting--when one commutator bar or
plate comes out of contact with the collecting-brush a spark is apt to
appear on the commutator. This spark may be due to the break of the
complete circuit, or to a shunt of low resistance formed by the brush
between two or more commutator-bars. In the first case the spark is more
apparent, as there is at the moment when the circuit is broken a
discharge of the magnets through the field helices, producing a great
spark or flash which causes an unsteady current, rapid wear of the
commutator bars and brushes, and waste of power. The sparking may be
reduced by various devices, such as providing a path for the current at
the moment when the commutator segment or bar leaves the brush, by
short-circuiting the field-helices, by increasing the number of the
commutator-bars, or by other similar means; but all these devices are
expensive or not fully available, and seldom attain the object desired.

To prevent this sparking in a simple manner, Mr. Tesla some years ago
employed with the commutator-bars and intervening insulating material,
mica, asbestos paper or other insulating and incombustible material,
arranged to bear on the surface of the commutator, near to and behind
the brush.

In the drawings, Fig. 244 is a section of a commutator with an asbestos
insulating device; and Fig. 245 is a similar view, representing two
plates of mica upon the back of the brush.

In 244, C represents the commutator and intervening insulating material;
B B, the brushes. _d d_ are sheets of asbestos paper or other suitable
non-conducting material. _f f_ are springs, the pressure of which may be
adjusted by means of the screws _g g_.

In Fig. 245 a simple arrangement is shown with two plates of mica or
other material. It will be seen that whenever one commutator segment
passes out of contact with the brush, the formation of the arc will be
prevented by the intervening insulating material coming in contact with
the insulating material on the brush.

[Illustration: FIG. 244.]

[Illustration: FIG. 245.]

Asbestos paper or cloth impregnated with zinc-oxide, magnesia, zirconia,
or other suitable material, may be used, as the paper and cloth are
soft, and serve at the same time to wipe and polish the commutator; but
mica or any other suitable material can be employed, provided the
material be an insulator or a bad conductor of electricity.

A few years later Mr. Tesla turned his attention again to the same
subject, as, perhaps, was very natural in view of the fact that the
commutator had always been prominent in his thoughts, and that so much
of his work was even aimed at dispensing with it entirely as an
objectionable and unnecessary part of dynamos and motors. In these later
efforts to remedy commutator troubles, Mr. Tesla constructs a commutator
and the collectors therefor in two parts mutually adapted to one
another, and, so far as the essential features are concerned, alike in
mechanical structure. Selecting as an illustration a commutator of two
segments adapted for use with an armature the coils or coil of which
have but two free ends, connected respectively to the segments, the
bearing-surface is the face of a disc, and is formed of two metallic
quadrant segments and two insulating segments of the same dimensions,
and the face of the disc is smoothed off, so that the metal and
insulating segments are flush. The part which takes the place of the
usual brushes, or the "collector," is a disc of the same character as
the commutator and has a surface similarly formed with two insulating
and two metallic segments. These two parts are mounted with their faces
in contact and in such manner that the rotation of the armature causes
the commutator to turn upon the collector, whereby the currents induced
in the coils are taken off by the collector segments and thence
conveyed off by suitable conductors leading from the collector segments.
This is the general plan of the construction adopted. Aside from certain
adjuncts, the nature and functions of which are set forth later, this
means of commutation will be seen to possess many important advantages.
In the first place the short-circuiting and the breaking of the armature
coil connected to the commutator-segments occur at the same instant, and
from the nature of the construction this will be done with the greatest
precision; secondly, the duration of both the break and of the short
circuit will be reduced to a minimum. The first results in a reduction
which amounts practically to a suppression of the spark, since the break
and the short circuit produce opposite effects in the armature-coil. The
second has the effect of diminishing the destructive effect of a spark,
since this would be in a measure proportional to the duration of the
spark; while lessening the duration of the short circuit obviously
increases the efficiency of the machine.

[Illustration: FIG. 246.]

[Illustration: FIG. 247.]

The mechanical advantages will be better understood by referring to the
accompanying diagrams, in which Fig. 246 is a central longitudinal
section of the end of a shaft with the improved commutator carried
thereon. Fig. 247 is a view of the inner or bearing face of the
collector. Fig. 248 is an end view from the armature side of a modified
form of commutator. Figs. 249 and 250 are views of details of Fig. 248.
Fig. 251 is a longitudinal central section of another modification, and
Fig. 252 is a sectional view of the same. A is the end of the
armature-shaft of a dynamo-electric machine or motor. A' is a sleeve of
insulating material around the shaft, secured in place by a screw, _a'_.

[Illustration: FIG. 248.]

[Illustration: FIG. 249.]

[Illustration: FIG. 250.]

The commutator proper is in the form of a disc which is made up of four
segments D D' G G', similar to those shown in Fig. 248. Two of these
segments, as D D', are of metal and are in electrical connection with
the ends of the coils on the armature. The other two segments are of
insulating material. The segments are held in place by a band, B, of
insulating material. The disc is held in place by friction or by screws,
_g' g'_, Fig. 248, which secure the disc firmly to the sleeve A'.

The collector is made in the same form as the commutator. It is composed
of the two metallic segments E E' and the two insulating segments F F',
bound together by a band, C. The metallic segments E E' are of the same
or practically the same width or extent as the insulating segments or
spaces of the commutator. The collector is secured to a sleeve, B', by
screws _g g_, and the sleeve is arranged to turn freely on the shaft A.
The end of the sleeve B' is closed by a plate, _f_, upon which presses a
pivot-pointed screw, _h_, adjustable in a spring, H, which acts to
maintain the collector in close contact with the commutator and to
compensate for the play of the shaft. The collector is so fixed that it
cannot turn with the shaft. For example, the diagram shows a slotted
plate, K, which is designed to be attached to a stationary support, and
an arm extending from the collector and carrying a clamping screw, L, by
which the collector may be adjusted and set to the desired position.

Mr. Tesla prefers the form shown in Figs. 246 and 247 to fit the
insulating segments of both commutator and collector loosely and to
provide some means--as, for example, light springs, _e e_, secured to
the bands A' B', respectively, and bearing against the segments--to
exert a light pressure upon them and keep them in close contact and to
compensate for wear. The metal segments of the commutator may be moved
forward by loosening the screw _a'_.

The line wires are fed from the metal segments of the collector, being
secured thereto in any convenient manner, the plan of connections being
shown as applied to a modified form of the commutator in Fig. 251. The
commutator and the collector in thus presenting two flat and smooth
bearing surfaces prevent most effectually by mechanical action the
occurrence of sparks.

The insulating segments are made of some hard material capable of being
polished and formed with sharp edges. Such materials as glass, marble,
or soapstone may be advantageously used. The metal segments are
preferably of copper or brass; but they may have a facing or edge of
durable material--such as platinum or the like--where the sparks are
liable to occur.

[Illustration: FIG. 251.]

[Illustration: FIG. 252.]

In Fig. 248 a somewhat modified form of the invention is shown, a form
designed to facilitate the construction and replacing of the parts. In
this modification the commutator and collector are made in substantially
the same manner as previously described, except that the bands B C are
omitted. The four segments of each part, however, are secured to their
respective sleeves by screws _g' g'_, and one edge of each segment is
cut away, so that small plates _a b_ may be slipped into the spaces thus
formed. Of these plates _a a_ are of metal, and are in contact with the
metal segments D D', respectively. The other two, _b b_, are of glass or
marble, and they are all better square, as shown in Figs. 249 and 250,
so that they may be turned to present new edges should any edge become
worn by use. Light springs _d_ bear upon these plates and press those in
the commutator toward those in the collector, and insulating strips _c
c_ are secured to the periphery of the discs to prevent the blocks from
being thrown out by centrifugal action. These plates are, of course,
useful at those edges of the segments only where sparks are liable to
occur, and, as they are easily replaced, they are of great advantage. It
is considered best to coat them with platinum or silver.

In Figs. 251 and 252 is shown a construction where, instead of solid
segments, a fluid is employed. In this case the commutator and collector
are made of two insulating discs, S T, and in lieu of the metal segments
a space is cut out of each part, as at R R', corresponding in shape and
size to a metal segment. The two parts are fitted smoothly and the
collector T held by the screw _h_ and spring H against the commutator S.
As in the other cases, the commutator revolves while the collector
remains stationary. The ends of the coils are connected to binding-posts
_s s_, which are in electrical connection with metal plates _t t_ within
the recesses in the two parts S T. These chambers or recesses are filled
with mercury, and in the collector part are tubes W W, with screws _w
w_, carrying springs X and pistons X', which compensate for the
expansion and contraction of the mercury under varying temperatures, but
which are sufficiently strong not to yield to the pressure of the fluid
due to centrifugal action, and which serve as binding-posts.

In all the above cases the commutators are adapted for a single coil,
and the device is particularly suited to such purposes. The number of
segments may be increased, however, or more than one commutator used
with a single armature. Although the bearing-surfaces are shown as
planes at right angles to the shaft or axis, it is evident that in this
particular the construction may be very greatly modified.




CHAPTER XXXVIII.

AUXILIARY BRUSH REGULATION OF DIRECT CURRENT DYNAMOS.


An interesting method devised by Mr. Tesla for the regulation of direct
current dynamos, is that which has come to be known as the "third brush"
method. In machines of this type, devised by him as far back as 1885, he
makes use of two main brushes to which the ends of the field magnet
coils are connected, an auxiliary brush, and a branch or shunt
connection from an intermediate point of the field wire to the auxiliary
brush.[14]

  [14] The compiler has learned partially from statements made on
       several occasions in journals and partially by personal inquiry
       of Mr. Tesla, that a great deal of work in this interesting line
       is unpublished. In these inventions as will be seen, the brushes
       are automatically shifted, but in the broad method barely
       suggested here the regulation is effected without any change in
       the position of the brushes. This auxiliary brush invention, it
       will be remembered, was very much discussed a few years ago, and
       it may be of interest that this work of Mr. Tesla, then unknown
       in this field, is now brought to light.

The relative positions of the respective brushes are varied, either
automatically or by hand, so that the shunt becomes inoperative when the
auxiliary brush has a certain position upon the commutator; but when the
auxiliary brush is moved in its relation to the main brushes, or the
latter are moved in their relation to the auxiliary brush, the electric
condition is disturbed and more or less of the current through the
field-helices is diverted through the shunt or a current is passed over
the shunt to the field-helices. By varying the relative position upon
the commutator of the respective brushes automatically in proportion to
the varying electrical conditions of the working-circuit, the current
developed can be regulated in proportion to the demands in the
working-circuit.

Fig. 253 is a diagram illustrating the invention, showing one core of
the field-magnets with one helix wound in the same direction throughout.
Figs. 254 and 255 are diagrams showing one core of the field-magnets
with a portion of the helices wound in opposite directions. Figs. 256
and 257 are diagrams illustrating the electric devices that may be
employed for automatically adjusting the brushes, and Fig. 258 is a
diagram illustrating the positions of the brushes when the machine is
being energized at the start.

_a_ and _b_ are the positive and negative brushes of the main or
working-circuit, and _c_ the auxiliary brush. The working-circuit D
extends from the brushes _a_ and _b_, as usual, and contains electric
lamps or other devices, D', either in series or in multiple arc.

M M' represent the field-helices, the ends of which are connected to the
main brushes _a_ and _b_. The branch or shunt wire _c'_ extends from the
auxiliary brush _c_ to the circuit of the field-helices, and is
connected to the same at an intermediate point, _x_.

[Illustration: FIG. 253.]

H represents the commutator, with the plates of ordinary construction.
When the auxiliary brush _c_ occupies such a position upon the
commutator that the electro-motive force between the brushes _a_ and _c_
is to the electro-motive force between the brushes _c_ and _b_ as the
resistance of the circuit _a_ M _c' c_ A is to the resistance of the
circuit _b_ M' _c' c_ B, the potentials of the points _x_ and Y will be
equal, and no current will flow over the auxiliary brush; but when the
brush _c_ occupies a different position the potentials of the points _x_
and Y will be different, and a current will flow over the auxiliary
brush to and from the commutator, according to the relative position of
the brushes. If, for instance, the commutator-space between the brushes
_a_ and _c_, when the latter is at the neutral point, is diminished, a
current will flow from the point Y over the shunt _c_ to the brush _b_,
thus strengthening the current in the part M', and partly neutralizing
the current in part M; but if the space between the brushes _a_ and _c_
is increased, the current will flow over the auxiliary brush in an
opposite direction, and the current in M will be strengthened, and in
M', partly neutralized.

By combining with the brushes _a_, _b_, and _c_ any usual automatic
regulating mechanism, the current developed can be regulated in
proportion to the demands in the working circuit. The parts M and M' of
the field wire may be wound in the same direction. In this case they are
arranged as shown in Fig. 253; or the part M may be wound in the
opposite direction, as shown in Figs. 254 and 255.

[Illustration: FIG. 254.]

It will be apparent that the respective cores of the field-magnets are
subjected to neutralizing or intensifying effects of the current in the
shunt through _c'_, and the magnetism of the cores will be partially
neutralized, or the points of greatest magnetism shifted, so that it
will be more or less remote from or approaching to the armature, and
hence the aggregate energizing actions of the field magnets on the
armature will be correspondingly varied.

In the form indicated in Fig. 253 the regulation is effected by shifting
the point of greatest magnetism, and in Figs. 254 and 255 the same
effect is produced by the action of the current in the shunt passing
through the neutralizing helix.

The relative positions of the respective brushes may be varied by moving
the auxiliary brush, or the brush _c_ may remain stationary and the core
P be connected to the main-brush holder A, so as to adjust the brushes
_a b_ in their relation to the brush _c_. If, however, an adjustment is
applied to all the brushes, as seen in Fig. 257, the solenoid should be
connected to both _a_ and _c_, so as to move them toward or away from
each other.

There are several known devices for giving motion in proportion to an
electric current. In Figs. 256 and 257 the moving cores are shown as
convenient devices for obtaining the required extent of motion with very
slight changes in the current passing through the helices. It is
understood that the adjustment of the main brushes causes variations in
the strength of the current independently of the relative position of
those brushes to the auxiliary brush. In all cases the adjustment should
be such that no current flows over the auxiliary brush when the dynamo
is running with its normal load.

In Figs. 256 and 257 A A indicate the main-brush holder, carrying the
main brushes, and C the auxiliary-brush holder, carrying the auxiliary
brush. These brush-holders are movable in arcs concentric with the
centre of the commutator-shaft. An iron piston, P, of the solenoid S,
Fig. 256, is attached to the auxiliary-brush holder C. The adjustment is
effected by means of a spring and screw or tightener.

In Fig. 257 instead of a solenoid, an iron tube inclosing a coil is
shown. The piston of the coil is attached to both brush-holders A A and
C. When the brushes are moved directly by electrical devices, as shown
in Figs. 256 and 257, these are so constructed that the force exerted
for adjusting is practically uniform through the whole length of motion.

[Illustration: FIG. 255.]

It is true that auxiliary brushes have been used in connection with the
helices of the field-wire; but in these instances the helices receive
the entire current through the auxiliary brush or brushes, and these
brushes could not be taken off without breaking the circuit through the
field. These brushes cause, moreover, heavy sparking at the commutator.
In the present case the auxiliary brush causes very little or no
sparking, and can be taken off without breaking the circuit through the
field-helices. The arrangement has, besides, the advantage of
facilitating the self-excitation of the machine in all cases where the
resistance of the field-wire is very great comparatively to the
resistance of the main circuit at the start--for instance, on arc-light
machines. In this case the auxiliary brush _c_ is placed near to, or
better still in contact with, the brush _b_, as shown in Fig. 258. In
this manner the part M' is completely cut out, and as the part M has a
considerably smaller resistance than the whole length of the field-wire
the machine excites itself, whereupon the auxiliary brush is shifted
automatically to its normal position.

[Illustration: FIG. 256.]

[Illustration: FIG. 257.]

In a further method devised by Mr. Tesla, one or more auxiliary brushes
are employed, by means of which a portion or the whole of the field
coils is shunted. According to the relative position upon the commutator
of the respective brushes more or less current is caused to pass through
the helices of the field, and the current developed by the machine can
be varied at will by varying the relative positions of the brushes.

[Illustration: FIG. 258.]

In Fig. 259, _a_ and _b_ are the positive and negative brushes of the
main circuit, and _c_ an auxiliary brush. The main circuit D extends
from the brushes _a_ and _b_, as usual, and contains the helices M of
the field wire and the electric lamps or other working devices. The
auxiliary brush _c_ is connected to the point _x_ of the main circuit by
means of the wire _c'_. H is a commutator of ordinary construction. It
will have been seen from what was said already that when the
electro-motive force between the brushes _a_ and _c_ is to the
electromotive force between the brushes _c_ and _b_ as the resistance of
the circuit _a_ M _c' c_ A is to the resistance of the circuit _b_ C B
_c c'_ D, the potentials of the points _x_ and _y_ will be equal, and no
current will pass over the auxiliary brush _c_; but if that brush
occupies a different position relatively to the main brushes the
electric condition is disturbed, and current will flow either from _y_
to _x_ or from _x_ to _y_, according to the relative position of the
brushes. In the first case the current through the field-helices will be
partly neutralized and the magnetism of the field magnets will be
diminished. In the second case the current will be increased and the
magnets gain strength. By combining with the brushes at _a b c_ any
automatic regulating mechanism, the current developed can be regulated
automatically in proportion to the demands of the working circuit.

In Figs. 264 and 265 some of the automatic means are represented that
maybe used for moving the brushes. The core P, Fig. 264, of the
solenoid-helix S is connected with the brush _a_ to move the same, and
in Fig. 265 the core P is shown as within the helix S, and connected
with brushes _a_ and _c_, so as to move the same toward or from each
other, according to the strength of the current in the helix, the helix
being within an iron tube, S', that becomes magnetized and increases the
action of the solenoid.

In practice it is sufficient to move only the auxiliary brush, as shown
in Fig. 264, as the regulation is very sensitive to the slightest
changes; but the relative position of the auxiliary brush to the main
brushes may be varied by moving the main brushes, or both main and
auxiliary brushes may be moved, as illustrated in Fig. 265. In the
latter two cases, it will be understood, the motion of the main brushes
relatively to the neutral line of the machine causes variations in the
strength of the current independently of their relative position to the
auxiliary brush. In all cases the adjustment may be such that when the
machine is running with the ordinary load, no current flows over the
auxiliary brush.

The field helices may be connected, as shown in Fig. 259, or a part of
the field helices may be in the outgoing and the other part in the
return circuit, and two auxiliary brushes may be employed as shown in
Figs. 261 and 262. Instead of shunting the whole of the field helices, a
portion only of such helices may be shunted, as shown in Figs. 260 and
262.

The arrangement shown in Fig. 262 is advantageous, as it diminishes the
sparking upon the commutator, the main circuit being closed through the
auxiliary brushes at the moment of the break of the circuit at the main
brushes.

[Illustration: FIG. 259.]

[Illustration: FIG. 260.]

[Illustration: FIG. 261.]

[Illustration: FIG. 262.]

[Illustration: FIG. 263.]

The field helices may be wound in the same direction, or a part may be
wound in opposite directions.

The connection between the helices and the auxiliary brush or brushes
may be made by a wire of small resistance, or a resistance may be
interposed (R, Fig. 263,) between the point _x_ and the auxiliary brush
or brushes to divide the sensitiveness when the brushes are adjusted.

[Illustration: FIG. 264.]

[Illustration: FIG. 265.]

The accompanying sketches also illustrate improvements made by Mr. Tesla
in the mechanical devices used to effect the shifting of the brushes, in
the use of an auxiliary brush. Fig. 266 is an elevation of the regulator
with the frame partly in section; and Fig. 267 is a section at the line
_x x_, Fig. 266. C is the commutator; B and B', the brush-holders, B
carrying the main brushes _a a'_, and B' the auxiliary or shunt brushes
_b b_. The axis of the brush-holder B is supported by two pivot-screws,
_p p_. The other brush-holder, B', has a sleeve, _d_, and is movable
around the axis of the brush-holder B. In this way both brush-holders
can turn very freely, the friction of the parts being reduced to a
minimum. Over the brush-holders is mounted the solenoid S, which rests
upon a forked column, _c_. This column also affords a support for the
pivots _p p_, and is fastened upon a solid bracket or projection, P,
which extends from the base of the machine, and is cast in one piece
with the same. The brush-holders B B' are connected by means of the
links _e e_ and the cross-piece F to the iron core I, which slides
freely in the tube T of the solenoid. The iron core I has a screw, _s_,
by means of which it can be raised and adjusted in its position
relatively to the solenoid, so that the pull exerted upon it by the
solenoid is practically uniform through the whole length of motion which
is required to effect the regulation. In order to effect the adjustment
with greater precision, the core I is provided with a small iron screw,
_s'_. The core being first brought very nearly in the required position
relatively to the solenoid by means of the screw _s_, the small screw
_s'_ is then adjusted until the magnetic attraction upon the core is the
same when the core is in any position. A convenient stop, _t_, serves to
limit the upward movement of the iron core.

To check somewhat the movement of the core I, a dash-pot, K, is used.
The piston L of the dash-pot is provided with a valve, V, which opens by
a downward pressure and allows an easy downward movement of the iron
core I, but closes and checks the movement of the core when it is pulled
up by the action of the solenoid.

To balance the opposing forces, the weight of the moving parts, and the
pull exerted by the solenoid upon the iron core, the weights W W may be
used. The adjustment is such that when the solenoid is traversed by the
normal current it is just strong enough to balance the downward pull of
the parts.

[Illustration: FIG. 266.]

[Illustration: FIG. 267.]

The electrical circuit-connections are substantially the same as
indicated in the previous diagrams, the solenoid being in series with
the circuit when the translating devices are in series, and in shunt
when the devices are in multiple arc. The operation of the device is as
follows: When upon a decrease of the resistance of the circuit or for
some other reason, the current is increased, the solenoid S gains in
strength and pulls up the iron core I, thus shifting the main brushes in
the direction of rotation and the auxiliary brushes in the opposite way.
This diminishes the strength of the current until the opposing forces
are balanced and the solenoid is traversed by the normal current; but if
from any cause the current in the circuit is diminished, then the weight
of the moving parts overcomes the pull of the solenoid, the iron core I
descends, thus shifting the brushes the opposite way and increasing the
current to the normal strength. The dash-pot connected to the iron core
I may be of ordinary construction; but it is better, especially in
machines for arc lights, to provide the piston of the dash-pot with a
valve, as indicated in the diagrams. This valve permits a comparatively
easy downward movement of the iron core, but checks its movement when it
is drawn up by the solenoid. Such an arrangement has the advantage that
a great number of lights may be put on without diminishing the
light-power of the lamps in the circuit, as the brushes assume at once
the proper position. When lights are cut out, the dash-pot acts to
retard the movement; but if the current is considerably increased the
solenoid gets abnormally strong and the brushes are shifted instantly.
The regulator being properly adjusted, lights or other devices may be
put on or out with scarcely any perceptible difference. It is obvious
that instead of the dash-pot any other retarding device may be used.




CHAPTER XXXIX.

IMPROVEMENT IN THE CONSTRUCTION OF DYNAMOS AND MOTORS.


This invention of Mr. Tesla is an improvement in the construction of
dynamo or magneto electric machines or motors, consisting in a novel
form of frame and field magnet which renders the machine more solid and
compact as a structure, which requires fewer parts, and which involves
less trouble and expense in its manufacture. It is applicable to
generators and motors generally, not only to those which have
independent circuits adapted for use in the Tesla alternating current
system, but to other continuous or alternating current machines of the
ordinary type generally used.

Fig. 268 shows the machine in side elevation. Fig. 269 is a vertical
sectional view of the field magnets and frame and an end view of the
armature; and Fig. 270 is a plan view of one of the parts of the frame
and the armature, a portion of the latter being cut away.

The field magnets and frame are cast in two parts. These parts are
identical in size and shape, and each consists of the solid plates or
ends A B, from which project inwardly the cores C D and the side bars or
bridge pieces, E F. The precise shape of these parts is largely a matter
of choice--that is to say, each casting, as shown, forms an
approximately rectangular frame; but it might obviously be more or less
oval, round, or square, without departure from the invention. It is also
desirable to reduce the width of the side bars, E F, at the center and
to so proportion the parts that when the frame is put together the
spaces between the pole pieces will be practically equal to the arcs
which the surfaces of the poles occupy.

The bearings G for the armature shaft are cast in the side bars E F. The
field coils are either wound on the pole pieces or on a form and then
slipped on over the ends of the pole pieces. The lower part or casting
is secured to the base after being finished off. The armature K on its
shaft is then mounted in the bearings of the lower casting and the
other part of the frame placed in position, dowel pins L or any other
means being used to secure the two parts in proper position.

[Illustration: FIG. 268.]

[Illustration: FIG. 269.]

[Illustration: FIG. 270.]

In order to secure an easier fit, the side bars E F, and end pieces, A
B, are so cast that slots M are formed when the two parts are put
together.

This machine possesses several advantages. For example, if we magnetize
the cores alternately, as indicated by the characters N S, it will be
seen that the magnetic circuit between the poles of each part of a
casting is completed through the solid iron side bars. The bearings for
the shaft are located at the neutral points of the field, so that the
armature core is not affected by the magnetic condition of the field.

The improvement is not restricted to the use of four pole pieces, as it
is evident that each pole piece could be divided or more than four
formed by the shape of the casting.




CHAPTER XL.

TESLA DIRECT CURRENT ARC LIGHTING SYSTEM.


At one time, soon after his arrival in America, Mr. Tesla was greatly
interested in the subject of arc lighting, which then occupied public
attention and readily enlisted the support of capital. He therefore
worked out a system which was confided to a company formed for its
exploitation, and then proceeded to devote his energies to the
perfection of the details of his more celebrated "rotary field" motor
system. The Tesla arc lighting apparatus appeared at a time when a great
many other lamps and machines were in the market, but it commanded
notice by its ingenuity. Its chief purpose was to lessen the
manufacturing cost and simplify the processes of operation.

We will take up the dynamo first. Fig. 271 is a longitudinal section,
and Fig. 272 a cross section of the machine. Fig. 273 is a top view, and
Fig. 274 a side view of the magnetic frame. Fig. 275 is an end view of
the commutator bars, and Fig. 276 is a section of the shaft and
commutator bars. Fig. 277 is a diagram illustrating the coils of the
armature and the connections to the commutator plates.

The cores _c c c c_ of the field-magnets are tapering in both
directions, as shown, for the purposes of concentrating the magnetism
upon the middle of the pole-pieces.

The connecting-frame F F of the field-magnets is in the form indicated
in the side view, Fig. 274, the lower part being provided with the
spreading curved cast legs _e e_, so that the machine will rest firmly
upon two base-bars, _r r_.

To the lower pole, S, of the field-magnet M is fastened, by means of
babbitt or other fusible diamagnetic material, the base B, which is
provided with bearings _b_ for the armature-shaft H. The base B has a
projection, P, which supports the brush-holders and the regulating
devices, which are of a special character devised by Mr. Tesla.

The armature is constructed with the view to reduce to a minimum the
loss of power due to Foucault currents and to the change of polarity,
and also to shorten as much as possible the length of the inactive wire
wound upon the armature core.

[Illustration: FIG. 271.]

It is well known that when the armature is revolved between the poles of
the field-magnets, currents are generated in the iron body of the
armature which develop heat, and consequently cause a waste of power.
Owing to the mutual action of the lines of force, the magnetic
properties of iron, and the speed of the different portions of the
armature core, these currents are generated principally on and near the
surface of the armature core, diminishing in strength gradually toward
the centre of the core. Their quantity is under some conditions
proportional to the length of the iron body in the direction in which
these currents are generated. By subdividing the iron core electrically
in this direction, the generation of these currents can be reduced to a
great extent. For instance, if the length of the armature-core is twelve
inches, and by a suitable construction it is subdivided electrically, so
that there are in the generating direction six inches of iron and six
inches of intervening air-spaces or insulating material, the waste
currents will be reduced to fifty per cent.

As shown in the diagrams, the armature is constructed of thin iron discs
D D D, of various diameters, fastened upon the armature-shaft in a
suitable manner and arranged according to their sizes, so that a series
of iron bodies, _i i i_, is formed, each of which diminishes in
thickness from the centre toward the periphery. At both ends of the
armature the inwardly curved discs _d d_, of cast iron, are fastened to
the armature shaft.

The armature core being constructed as shown, it will be easily seen
that on those portions of the armature that are the most remote from the
axis, and where the currents are principally developed, the length of
iron in the generating direction is only a small fraction of the total
length of the armature core, and besides this the iron body is
subdivided in the generating direction, and therefore the Foucault
currents are greatly reduced. Another cause of heating is the shifting
of the poles of the armature core. In consequence of the subdivision of
the iron in the armature and the increased surface for radiation, the
risk of heating is lessened.

The iron discs D D D are insulated or coated with some insulating-paint,
a very careful insulation being unnecessary, as an electrical contact
between several discs can only occur at places where the generated
currents are comparatively weak. An armature core constructed in the
manner described may be revolved between the poles of the field magnets
without showing the slightest increase of temperature.

[Illustration: FIG. 272.]

[Illustration: FIG. 273.]

The end discs, _d d_, which are of sufficient thickness and, for the
sake of cheapness, of cast-iron, are curved inwardly, as indicated in
the drawings. The extent of the curve is dependent on the amount of wire
to be wound upon the armatures. In this machine the wire is wound upon
the armature in two superimposed parts, and the curve of the end discs,
_d d_, is so calculated that the first part--that is, practically half
of the wire--just fills up the hollow space to the line _x x_; or, if
the wire is wound in any other manner, the curve is such that when the
whole of the wire is wound, the outside mass of wires, _w_, and the
inside mass of wires, _w'_, are equal at each side of the plane _x x_.
In this case the passive or electrically-inactive wires are of the
smallest length practicable. The arrangement has further the advantage
that the total lengths of the crossing wires at the two sides of the
plane _x x_ are practically equal.

[Illustration: FIG. 274.]

To equalize further the armature coils at both sides of the plates that
are in contact with the brushes, the winding and connecting up is
effected in the following manner: The whole wire is wound upon the
armature-core in two superimposed parts, which are thoroughly insulated
from each other. Each of these two parts is composed of three separated
groups of coils. The first group of coils of the first part of wire
being wound and connected to the commutator-bars in the usual manner,
this group is insulated and the second group wound; but the coils of
this second group, instead of being connected to the next following
commutator bars, are connected to the directly opposite bars of the
commutator. The second group is then insulated and the third group
wound, the coils of this group being connected to those bars to which
they would be connected in the usual way. The wires are then thoroughly
insulated and the second part of wire is wound and connected in the same
manner.

Suppose, for instance, that there are twenty-four coils--that is, twelve
in each part--and consequently twenty-four commutator plates. There will
be in each part three groups, each containing four coils, and the coils
will be connected as follows:

                        _Groups._   _Commutator Bars._
                      { First            1--5
  First part of wire  { Second          17--21
                      { Third            9--13

                      { First           13--17
  Second part of wire { Second           5--9
                      { Third           21--1

In constructing the armature core and winding and connecting the coils
in the manner indicated, the passive or electrically inactive wire is
reduced to a minimum, and the coils at each side of the plates that are
in contact with the brushes are practically equal. In this way the
electrical efficiency of the machine is increased.

[Illustration: FIG. 275.]

[Illustration: FIG. 276.]

The commutator plates _t_ are shown as outside the bearing _b_ of the
armature shaft. The shaft H is tubular and split at the end portion, and
the wires are carried through the same in the usual manner and connected
to the respective commutator plates. The commutator plates are upon a
cylinder, _u_, and insulated, and this cylinder is properly placed and
then secured by expanding the split end of the shaft by a tapering screw
plug, _v_.

[Illustration: FIG. 277.]

The arc lamps invented by Mr. Tesla for use on the circuits from the
above described dynamo are those in which the separation and feed of the
carbon electrodes or their equivalents is accomplished by means of
electro-magnets or solenoids in connection with suitable clutch
mechanism, and were designed for the purpose of remedying certain
faults common to arc lamps.

He proposed to prevent the frequent vibrations of the movable carbon
"point" and flickering of the light arising therefrom; to prevent the
falling into contact of the carbons; to dispense with the dash pot,
clock work, or gearing and similar devices; to render the lamp extremely
sensitive, and to feed the carbon almost imperceptibly, and thereby
obtain a very steady and uniform light.

In that class of lamps where the regulation of the arc is effected by
forces acting in opposition on a free, movable rod or lever directly
connected with the electrode, all or some of the forces being dependent
on the strength of the current, any change in the electrical condition
of the circuit causes a vibration and a corresponding flicker in the
light. This difficulty is most apparent when there are only a few lamps
in circuit. To lessen this difficulty lamps have been constructed in
which the lever or armature, after the establishing of the arc, is kept
in a fixed position and cannot vibrate during the feed operation, the
feed mechanism acting independently; but in these lamps, when a clamp is
employed, it frequently occurs that the carbons come into contact and
the light is momentarily extinguished, and frequently parts of the
circuit are injured. In both these classes of lamps it has been
customary to use dash pot, clock work, or equivalent retarding devices;
but these are often unreliable and objectionable, and increase the cost
of construction.

Mr. Tesla combines two electro-magnets--one of low resistance in the
main or lamp circuit, and the other of comparatively high resistance in
a shunt around the arc--a movable armature lever, and a special feed
mechanism, the parts being arranged so that in the normal working
position of the armature lever the same is kept almost rigidly in one
position, and is not affected even by considerable changes in the
electric circuit; but if the carbons fall into contact the armature will
be actuated by the magnets so as to move the lever and start the arc,
and hold the carbons until the arc lengthens and the armature lever
returns to the normal position. After this the carbon rod holder is
released by the action of the feed mechanism, so as to feed the carbon
and restore the arc to its normal length.

Fig. 278 is an elevation of the mechanism made use of in this arc lamp.
Fig. 279 is a plan view. Fig. 280 is an elevation of the balancing lever
and spring; Fig. 281 is a detached plan view of the pole pieces and
armatures upon the friction clamp, and Fig. 282 is a section of the
clamping tube.

M is a helix of coarse wire in a circuit from the lower carbon holder to
the negative binding screw -. N is a helix of fine wire in a shunt
between the positive binding screw + and the negative binding screw -.
The upper carbon holder S is a parallel rod sliding through the plates
S' S^{2} of the frame of the lamp, and hence the electric current passes
from the positive binding post + through the plate S^{2}, carbon holder
S, and upper carbon to the lower carbon, and thence by the holder and a
metallic connection to the helix M.

[Illustration: FIG. 278.]

[Illustration: FIG. 279.]

[Illustration: FIG. 280.]

[Illustration: FIG. 281.]

[Illustration: FIG. 282.]

The carbon holders are of the usual character, and to insure electric
connections the springs _l_ are made use of to grasp the upper carbon
holding rod S, but to allow the rod to slide freely through the same.
These springs _l_ may be adjusted in their pressure by the screw _m_,
and the spring _l_ maybe sustained upon any suitable support. They are
shown as connected with the upper end of the core of the magnet N.

Around the carbon-holding rod S, between the plates S' S^{2}, there is a
tube, R, which forms a clamp. This tube is counter-bored, as seen in the
section Fig. 282, so that it bears upon the rod S at its upper end and
near the middle, and at the lower end of this tubular clamp R there are
armature segments _r_ of soft iron. A frame or arm, _n_, extending,
preferably, from the core N^{2}, supports the lever A by a fulcrum-pin,
_o_. This lever A has a hole, through which the upper end of the tubular
clamp R passes freely, and from the lever A is a link, _q_, to the lever
_t_, which lever is pivoted at _y_ to a ring upon one of the columns
S^{3}. This lever _t_ has an opening or bow surrounding the tubular
clamp R, and there are pins or pivotal connections _w_ between the lever
_t_ and this clamp R, and a spring, _r^{2}_, serves to support or
suspend the weight of the parts and balance them, or nearly so. This
spring is adjustable.

At one end of the lever A is a soft-iron armature block, _a_, over the
core M' of the helix M, and there is a limiting screw, _c_, passing
through this armature block _a_, and at the other end of the lever A is
a soft iron armature block, _b_, with the end tapering or wedge shaped,
and the same comes close to and in line with the lateral projection _e_
on the core N^{2}. The lower ends of the cores M' N^{2} are made with
laterally projecting pole-pieces M^{3} N^{3}, respectively, and these
pole-pieces are concave at their outer ends, and are at opposite sides
of the armature segments _r_ at the lower end of the tubular clamp R.

The operation of these devices is as follows: In the condition of
inaction, the upper carbon rests upon the lower one, and when the
electric current is turned on it passes freely, by the frame and spring
_l_, through the rods and carbons to the coarse wire and helix M, and to
the negative binding post V and the core M' thereby is energized. The
pole piece M^{3} attracts the armature _r_, and by the lateral pressure
causes the clamp R to grasp the rod S', and the lever A is
simultaneously moved from the position shown by dotted lines, Fig. 278,
to the normal position shown in full lines, and in so doing the link _q_
and lever _t_ are raised, lifting the clamp R and S, separating the
carbons and forming the arc. The magnetism of the pole piece _e_ tends
to hold the lever A level, or nearly so, the core N^{2} being energized
by the current in the shunt which contains the helix N. In this position
the lever A is not moved by any ordinary variation in the current,
because the armature _b_ is strongly attracted by the magnetism of _e_,
and these parts are close to each other, and the magnetism of _e_ acts
at right angles to the magnetism of the core M'. If, now, the arc
becomes too long, the current through the helix M is lessened, and the
magnetism of the core N^{3} is increased by the greater current passing
through the shunt, and this core N^{3}, attracting the segmental
armature _r_, lessens the hold of the clamp R upon the rod S, allowing
the latter to slide and lessen the length of the arc, which instantly
restores the magnetic equilibrium and causes the clamp R to hold the rod
S. If it happens that the carbons fall into contact, then the magnetism
of N^{2} is lessened so much that the attraction of the magnet M will be
sufficient to move the armature _a_ and lever A so that the armature _b_
passes above the normal position, so as to separate the carbons
instantly; but when the carbons burn away, a greater amount of current
will pass through the shunt until the attraction of the core N^{2} will
overcome the attraction of the core M' and bring the armature lever A
again into the normal horizontal position, and this occurs before the
feed can take place. The segmental armature pieces _r_ are shown as
nearly semicircular. They are square or of any other desired shape, the
ends of the pole pieces M^{3}, N^{3} being made to correspond in shape.

In a modification of this lamp, Mr. Tesla provided means for
automatically withdrawing a lamp from the circuit, or cutting it out
when, from a failure of the feed, the arc reached an abnormal length;
and also means for automatically reinserting such lamp in the circuit
when the rod drops and the carbons come into contact.

Fig. 283 is an elevation of the lamp with the case in section. Fig. 284
is a sectional plan at the line _x x_. Fig. 285 is an elevation, partly
in section, of the lamp at right angles to Fig. 283. Fig. 286 is a
sectional plan at the line _y y_ of Fig. 283. Fig. 287 is a section of
the clamp in about full size. Fig. 288 is a detached section
illustrating the connection of the spring to the lever that carries the
pivots of the clamp, and Fig. 289 is a diagram showing the
circuit-connections of the lamp.

In Fig. 283, M represents the main and N the shunt magnet, both securely
fastened to the base A, which with its side columns, S S, are cast in
one piece of brass or other diamagnetic material. To the magnets are
soldered or otherwise fastened the brass washers or discs _a a a a_.
Similar washers, _b b_, of fibre or other insulating material, serve to
insulate the wires from the brass washers.

The magnets M and N are made very flat, so that their width exceeds
three times their thickness, or even more. In this way a comparatively
small number of convolutions is sufficient to produce the required
magnetism, while a greater surface is offered for cooling off the wires.

[Illustration: FIG. 286.]

[Illustration: FIG. 283.]

[Illustration: FIG. 285.]

[Illustration: FIG. 284.]

[Illustration: FIG. 287.]

[Illustration: FIG. 288.]

The upper pole pieces, _m n_, of the magnets are curved, as indicated in
the drawings, Fig. 283. The lower pole pieces _m' n'_, are brought near
together, tapering toward the armature _g_, as shown in Figs. 284 and
286. The object of this taper is to concentrate the greatest amount of
the developed magnetism upon the armature, and also to allow the pull to
be exerted always upon the middle of the armature _g_. This armature _g_
is a piece of iron in the shape of a hollow cylinder, having on each
side a segment cut away, the width of which is equal to the width of the
pole pieces _m' n'_.

The armature is soldered or otherwise fastened to the clamp _r_, which
is formed of a brass tube, provided with gripping-jaws _e e_, Fig. 287.
These jaws are arcs of a circle of the diameter of the rod R, and are
made of hardened German silver. The guides _f f_, through which the
carbon-holding rod R slides, are made of the same material. This has the
advantage of reducing greatly the wear and corrosion of the parts coming
in frictional contact with the rod, which frequently causes trouble. The
jaws _e e_ are fastened to the inside of the tube _r_, so that one is a
little lower than the other. The object of this is to provide a greater
opening for the passage of the rod when the same is released by the
clamp. The clamp _r_ is supported on bearings _w w_, Figs. 283, 285 and
287, which are just in the middle between the jaws _e e_. The bearings
_w w_ are carried by a lever, _t_, one end of which rests upon an
adjustable support, _q_, of the side columns, S, the other end being
connected by means of the link _e'_ to the armature-lever L. The
armature-lever L is a flat piece of iron in N shape, having its ends
curved so as to correspond to the form of the upper pole-pieces of the
magnets M and N. It is hung upon the pivots _v v_, Fig. 284, which are
in the jaw _x_ of the top plate B. This plate B, with the jaw, is cast
in one piece and screwed to the side columns, S S, that extend up from
the base A. To partly balance the overweight of the moving parts, a
spring, _s'_, Figs. 284 and 288, is fastened to the top plate, B, and
hooked to the lever _t_. The hook _o_ is toward one side of the lever or
bent a little sidewise, as seen in Fig. 288. By this means a slight
tendency is given to swing the armature toward the pole-piece _m'_ of
the main magnet.

The binding-posts K K' are screwed to the base A. A manual switch, for
short-circuiting the lamp when the carbons are renewed, is also fastened
to the base. This switch is of ordinary character, and is not shown in
the drawings.

The rod R is electrically connected to the lamp-frame by means of a
flexible conductor or otherwise. The lamp-case receives a removable
cover, _s^{2}_, to inclose the parts.

The electrical connections are as indicated diagrammatically in Fig.
289. The wire in the main magnet consists of two parts, _x'_ and _p'_.
These two parts may be in two separated coils or in one single helix,
as shown in the drawings. The part _x'_ being normally in circuit, is,
with the fine wire upon the shunt-magnet, wound and traversed by the
current in the same direction, so as to tend to produce similar poles, N
N or S S, on the corresponding pole-pieces of the magnets M and N. The
part _p'_ is only in circuit when the lamp is cut out, and then the
current being in the opposite direction produces in the main magnet,
magnetism of the opposite polarity.

The operation is as follows: At the start the carbons are to be in
contact, and the current passes from the positive binding-post K to the
lamp-frame, carbon-holder, upper and lower carbon, insulated return-wire
in one of the side rods, and from there through the part _x'_ of the
wire on the main magnet to the negative binding-post. Upon the passage
of the current the main magnet is energized and attracts the
clamping-armature _g_, swinging the clamp and gripping the rod by means
of the gripping jaws _e e_. At the same time the armature lever L is
pulled down and the carbons are separated. In pulling down the armature
lever L the main magnet is assisted by the shunt-magnet N, the latter
being magnetized by magnetic induction from the magnet M.

[Illustration: FIG. 289.]

It will be seen that the armatures L and _g_ are practically the keepers
for the magnets M and N, and owing to this fact both magnets with either
one of the armatures L and _g_ may be considered as one horseshoe
magnet, which we might term a "compound magnet." The whole of the
soft-iron parts M, _m'_, _g_, _n'_, N and L form a compound magnet.

The carbons being separated, the fine wire receives a portion of the
current. Now, the magnetic induction from the magnet M is such as to
produce opposite poles on the corresponding ends of the magnet N; but
the current traversing the helices tends to produce similar poles on the
corresponding ends of both magnets, and therefore as soon as the fine
wire is traversed by sufficient current the magnetism of the whole
compound magnet is diminished.

With regard to the armature _g_ and the operation of the lamp, the pole
_m'_ may be considered as the "clamping" and the pole _n'_ as the
"releasing" pole.

As the carbons burn away, the fine wire receives more current and the
magnetism diminishes in proportion. This causes the armature lever L to
swing and the armature _g_ to descend gradually under the weight of the
moving parts until the end _p_, Fig. 283, strikes a stop on the top
plate, B. The adjustment is such that when this takes place the rod R is
yet gripped securely by the jaws _e e_. The further downward movement of
the armature lever being prevented, the arc becomes longer as the
carbons are consumed, and the compound magnet is weakened more and more
until the clamping armature _g_ releases the hold of the gripping-jaws
_e e_ upon the rod R, and the rod is allowed to drop a little, thus
shortening the arc. The fine wire now receiving less current, the
magnetism increases, and the rod is clamped again and slightly raised,
if necessary. This clamping and releasing of the rod continues until the
carbons are consumed. In practice the feed is so sensitive that for the
greatest part of the time the movement of the rod cannot be detected
without some actual measurement. During the normal operation of the lamp
the armature lever L remains practically stationary, in the position
shown in Fig. 283.

Should it happen that, owing to an imperfection in it, the rod and the
carbons drop too far, so as to make the arc too short, or even bring the
carbons in contact, a very small amount of current passes through the
fine wire, and the compound magnet becomes sufficiently strong to act as
at the start in pulling the armature lever L down and separating the
carbons to a greater distance.

It occurs often in practical work that the rod sticks in the guides. In
this case the are reaches a great length, until it finally breaks. Then
the light goes out, and frequently the fine wire is injured. To prevent
such an accident Mr. Tesla provides this lamp with an automatic cut-out
which operates as follows: When, upon a failure of the feed, the arc
reaches a certain predetermined length, such an amount of current is
diverted through the fine wire that the polarity of the compound magnet
is reversed. The clamping armature _g_ is now moved against the shunt
magnet N until it strikes the releasing pole _n'_. As soon as the
contact is established, the current passes from the positive binding
post over the clamp _r_, armature _g_, insulated shunt magnet, and the
helix _p'_ upon the main magnet M to the negative binding post. In this
case the current passes in the opposite direction and changes the
polarity of the magnet M, at the same time maintaining by magnetic
induction in the core of the shunt magnet the required magnetism without
reversal of polarity, and the armature _g_ remains against the shunt
magnet pole _n'_. The lamp is thus cut out as long as the carbons are
separated. The cut out may be used in this form without any further
improvement; but Mr. Tesla arranges it so that if the rod drops and the
carbons come in contact the arc is started again. For this purpose he
proportions the resistance of part _p'_ and the number of the
convolutions of the wire upon the main magnet so that when the carbons
come in contact a sufficient amount of current is diverted through the
carbons and the part _x'_ to destroy or neutralize the magnetism of the
compound magnet. Then the armature _g_, having a slight tendency to
approach to the clamping pole _m'_, comes out of contact with the
releasing pole _n'_. As soon as this happens, the current through the
part _p'_ is interrupted, and the whole current passes through the part
_x_. The magnet M is now strongly magnetized, the armature _g_ is
attracted, and the rod clamped. At the same time the armature lever L is
pulled down out of its normal position and the arc started. In this way
the lamp cuts itself out automatically when the arc gets too long, and
reinserts itself automatically in the circuit if the carbons drop
together.




CHAPTER XLI.

IMPROVEMENT IN "UNIPOLAR" GENERATORS.


Another interesting class of apparatus to which Mr. Tesla has directed
his attention, is that of "unipolar" generators, in which a disc or a
cylindrical conductor is mounted between magnetic poles adapted to
produce an approximately uniform field. In the disc armature machines
the currents induced in the rotating conductor flow from the centre to
the periphery, or conversely, according to the direction of rotation or
the lines of force as determined by the signs of the magnetic poles, and
these currents are taken off usually by connections or brushes applied
to the disc at points on its periphery and near its centre. In the case
of the cylindrical armature machine, the currents developed in the
cylinder are taken off by brushes applied to the sides of the cylinder
at its ends.

In order to develop economically an electromotive force available for
practicable purposes, it is necessary either to rotate the conductor at
a very high rate of speed or to use a disc of large diameter or a
cylinder of great length; but in either case it becomes difficult to
secure and maintain a good electrical connection between the collecting
brushes and the conductor, owing to the high peripheral speed.

It has been proposed to couple two or more discs together in series,
with the object of obtaining a higher electro-motive force; but with the
connections heretofore used and using other conditions of speed and
dimension of disc necessary to securing good practicable results, this
difficulty is still felt to be a serious obstacle to the use of this
kind of generator. These objections Mr. Tesla has sought to avoid by
constructing a machine with two fields, each having a rotary conductor
mounted between its poles. The same principle is involved in the case of
both forms of machine above described, but the description now given is
confined to the disc type, which Mr. Tesla is inclined to favor for that
machine. The discs are formed with flanges, after the manner of
pulleys, and are connected together by flexible conducting bands or
belts.

The machine is built in such manner that the direction of magnetism or
order of the poles in one field of force is opposite to that in the
other, so that rotation of the discs in the same direction develops a
current in one from centre to circumference and in the other from
circumference to centre. Contacts applied therefore to the shafts upon
which the discs are mounted form the terminals of a circuit the
electro-motive force in which is the sum of the electro-motive forces of
the two discs.

It will be obvious that if the direction of magnetism in both fields be
the same, the same result as above will be obtained by driving the discs
in opposite directions and crossing the connecting belts. In this way
the difficulty of securing and maintaining good contact with the
peripheries of the discs is avoided and a cheap and durable machine made
which is useful for many purposes--such as for an exciter for
alternating current generators, for a motor, and for any other purpose
for which dynamo machines are used.

[Illustration: FIG. 290.]

[Illustration: FIG. 291.]

Fig. 290 is a side view, partly in section, of this machine. Fig. 291 is
a vertical section of the same at right angles to the shafts.

In order to form a frame with two fields of force, a support, A, is cast
with two pole pieces B B' integral with it. To this are joined by bolts
E a casting D, with two similar and corresponding pole pieces C C'. The
pole pieces B B' are wound and connected to produce a field of force of
given polarity, and the pole pieces C C' are wound so as to produce a
field of opposite polarity. The driving shafts F G pass through the
poles and are journaled in insulating bearings in the casting A D, as
shown.

H K are the discs or generating conductors. They are composed of copper,
brass, or iron and are keyed or secured to their respective shafts. They
are provided with broad peripheral flanges J. It is of course obvious
that the discs may be insulated from their shafts, if so desired. A
flexible metallic belt L is passed over the flanges of the two discs,
and, if desired, may be used to drive one of the discs. It is better,
however, to use this belt merely as a conductor, and for this purpose
sheet steel, copper, or other suitable metal is used. Each shaft is
provided with a driving pulley M, by which power is imparted from a
driving shaft.

N N are the terminals. For the sake of clearness they are shown as
provided with springs P, that bear upon the ends of the shafts. This
machine, if self-exciting, would have copper bands around its poles; or
conductors of any kind--such as wires shown in the drawings--may be
used.

       *       *       *       *       *

It is thought appropriate by the compiler to append here some notes on
unipolar dynamos, written by Mr. Tesla, on a recent occasion.


NOTES ON A UNIPOLAR DYNAMO.[15]

  [15] Article by Mr. Tesla, contributed to _The Electrical Engineer_,
       N. Y., Sept. 2, 1891.

It is characteristic of fundamental discoveries, of great achievements
of intellect, that they retain an undiminished power upon the
imagination of the thinker. The memorable experiment of Faraday with a
disc rotating between the two poles of a magnet, which has borne such
magnificent fruit, has long passed into every-day experience; yet there
are certain features about this embryo of the present dynamos and motors
which even to-day appear to us striking, and are worthy of the most
careful study.

Consider, for instance, the case of a disc of iron or other metal
revolving between the two opposite poles of a magnet, and the polar
surfaces completely covering both sides of the disc, and assume the
current to be taken off or conveyed to the same by contacts uniformly
from all points of the periphery of the disc. Take first the case of a
motor. In all ordinary motors the operation is dependent upon some
shifting or change of the resultant of the magnetic attraction exerted
upon the armature, this process being effected either by some mechanical
contrivance on the motor or by the action of currents of the proper
character. We may explain the operation of such a motor just as we can
that of a water-wheel. But in the above example of the disc surrounded
completely by the polar surfaces, there is no shifting of the magnetic
action, no change whatever, as far as we know, and yet rotation ensues.
Here, then, ordinary considerations do not apply; we cannot even give a
superficial explanation, as in ordinary motors, and the operation will
be clear to us only when we shall have recognized the very nature of the
forces concerned, and fathomed the mystery of the invisible connecting
mechanism.

Considered as a dynamo machine, the disc is an equally interesting
object of study. In addition to its peculiarity of giving currents of
one direction without the employment of commutating devices, such a
machine differs from ordinary dynamos in that there is no reaction
between armature and field. The armature current tends to set up a
magnetization at right angles to that of the field current, but since
the current is taken off uniformly from all points of the periphery, and
since, to be exact, the external circuit may also be arranged perfectly
symmetrical to the field magnet, no reaction can occur. This, however,
is true only as long as the magnets are weakly energized, for when the
magnets are more or less saturated, both magnetizations at right angles
seemingly interfere with each other.

For the above reason alone it would appear that the output of such a
machine should, for the same weight, be much greater than that of any
other machine in which the armature current tends to demagnetize the
field. The extraordinary output of the Forbes unipolar dynamo and the
experience of the writer confirm this view.

Again, the facility with which such a machine may be made to excite
itself is striking, but this may be due--besides to the absence of
armature reaction--to the perfect smoothness of the current and
non-existence of self-induction.

If the poles do not cover the disc completely on both sides, then, of
course, unless the disc be properly subdivided, the machine will be very
inefficient. Again, in this case there are points worthy of notice. If
the disc be rotated and the field current interrupted, the current
through the armature will continue to flow and the field magnets will
lose their strength comparatively slowly. The reason for this will at
once appear when we consider the direction of the currents set up in the
disc.

[Illustration: FIG. 292.]

Referring to the diagram Fig. 292, _d_ represents the disc with the
sliding contacts B B' on the shaft and periphery. N and S represent the
two poles of a magnet. If the pole N be above, as indicated in the
diagram, the disc being supposed to be in the plane of the paper, and
rotating in the direction of the arrow D, the current set up in the disc
will flow from the centre to the periphery, as indicated by the arrow A.
Since the magnetic action is more or less confined to the space between
the poles N S, the other portions of the disc may be considered
inactive. The current set up will therefore not wholly pass through the
external circuit F, but will close through the disc itself, and
generally, if the disposition be in any way similar to the one
illustrated, by far the greater portion of the current generated will
not appear externally, as the circuit F is practically short-circuited
by the inactive portions of the disc. The direction of the resulting
currents in the latter may be assumed to be as indicated by the dotted
lines and arrows _m_ and _n_; and the direction of the energizing field
current being indicated by the arrows _a b c d_, an inspection of the
figure shows that one of the two branches of the eddy current, that is,
A B' _m_ B, will tend to demagnetize the field, while the other branch,
that is, A B' _n_ B, will have the opposite effect. Therefore, the
branch A B' _m_ B, that is, the one which is _approaching_ the field,
will repel the lines of the same, while branch A B' _n_ B, that is, the
one _leaving_ the field, will gather the lines of force upon itself.

In consequence of this there will be a constant tendency to reduce the
current flow in the path A B' _m_ B, while on the other hand no such
opposition will exist in path A B' _n_ B, and the effect of the latter
branch or path will be more or less preponderating over that of the
former. The joint effect of both the assumed branch currents might be
represented by that of one single current of the same direction as that
energizing the field. In other words, the eddy currents circulating in
the disc will energize the field magnet. This is a result quite contrary
to what we might be led to suppose at first, for we would naturally
expect that the resulting effect of the armature currents would be such
as to oppose the field current, as generally occurs when a primary and
secondary conductor are placed in inductive relations to each other. But
it must be remembered that this results from the peculiar disposition in
this case, namely, two paths being afforded to the current, and the
latter selecting that path which offers the least opposition to its
flow. From this we see that the eddy currents flowing in the disc partly
energize the field, and for this reason when the field current is
interrupted the currents in the disc will continue to flow, and the
field magnet will lose its strength with comparative slowness and may
even retain a certain strength as long as the rotation of the disc is
continued.

The result will, of course, largely depend on the resistance and
geometrical dimensions of the path of the resulting eddy current and on
the speed of rotation; these elements, namely, determine the retardation
of this current and its position relative to the field. For a certain
speed there would be a maximum energizing action; then at higher speeds,
it would gradually fall off to zero and finally reverse, that is, the
resultant eddy current effect would be to weaken the field. The reaction
would be best demonstrated experimentally by arranging the fields N S,
N' S', freely movable on an axis concentric with the shaft of the disc.
If the latter were rotated as before in the direction of the arrow D,
the field would be dragged in the same direction with a torque, which,
up to a certain point, would go on increasing with the speed of
rotation, then fall off, and, passing through zero, finally become
negative; that is, the field would begin to rotate in opposite direction
to the disc. In experiments with alternate current motors in which the
field was shifted by currents of differing phase, this interesting
result was observed. For very low speeds of rotation of the field the
motor would show a torque of 900 lbs. or more, measured on a pulley 12
inches in diameter. When the speed of rotation of the poles was
increased, the torque would diminish, would finally go down to zero,
become negative, and then the armature would begin to rotate in opposite
direction to the field.

To return to the principal subject; assume the conditions to be such
that the eddy currents generated by the rotation of the disc strengthen
the field, and suppose the latter gradually removed while the disc is
kept rotating at an increased rate. The current, once started, may then
be sufficient to maintain itself and even increase in strength, and then
we have the case of Sir William Thomson's "current accumulator." But
from the above considerations it would seem that for the success of the
experiment the employment of a disc _not subdivided_[16] would be
essential, for if there should be a radial subdivision, the eddy
currents could not form and the self-exciting action would cease. If
such a radially subdivided disc were used it would be necessary to
connect the spokes by a conducting rim or in any proper manner so as to
form a symmetrical system of closed circuits.

  [16] Mr. Tesla here refers to an interesting article which appeared
       in July, 1865, in the _Phil. Magazine_, by Sir W. Thomson, in
       which Sir William, speaking of his "uniform electric current
       accumulator," assumes that for self-excitation it is desirable
       to subdivide the disc into an infinite number of infinitely thin
       spokes, in order to prevent diffusion of the current. Mr. Tesla
       shows that diffusion is absolutely necessary for the excitation
       and that when the disc is subdivided no excitation can occur.

The action of the eddy currents may be utilized to excite a machine of
any construction. For instance, in Figs. 293 and 294 an arrangement is
shown by which a machine with a disc armature might be excited. Here a
number of magnets, N S, N S, are placed radially on each side of a metal
disc D carrying on its rim a set of insulated coils, C C. The magnets
form two separate fields, an internal and an external one, the solid
disc rotating in the field nearest the axis, and the coils in the field
further from it. Assume the magnets slightly energized at the start;
they could be strengthened by the action of the eddy currents in the
solid disc so as to afford a stronger field for the peripheral coils.
Although there is no doubt that under proper conditions a machine might
be excited in this or a similar manner, there being sufficient
experimental evidence to warrant such an assertion, such a mode of
excitation would be wasteful.

But a unipolar dynamo or motor, such as shown in Fig. 292, may be
excited in an efficient manner by simply properly subdividing the disc
or cylinder in which the currents are set up, and it is practicable to
do away with the field coils which are usually employed. Such a plan is
illustrated in Fig. 295. The disc or cylinder D is supposed to be
arranged to rotate between the two poles N and S of a magnet, which
completely cover it on both sides, the contours of the disc and poles
being represented by the circles _d_ and _d^{1}_ respectively, the upper
pole being omitted for the sake of clearness. The cores of the magnet
are supposed to be hollow, the shaft C of the disc passing through them.
If the unmarked pole be below, and the disc be rotated screw fashion,
the current will be, as before, from the centre to the periphery, and
may be taken off by suitable sliding contacts, B B', on the shaft and
periphery respectively. In this arrangement the current flowing through
the disc and external circuit will have no appreciable effect on the
field magnet.

[Illustration: FIG. 293.]

[Illustration: FIG. 294.]

But let us now suppose the disc to be subdivided spirally, as indicated
by the full or dotted lines, Fig. 295. The difference of potential
between a point on the shaft and a point on the periphery will remain
unchanged, in sign as well as in amount. The only difference will be
that the resistance of the disc will be augmented and that there will be
a greater fall of potential from a point on the shaft to a point on the
periphery when the same current is traversing the external circuit. But
since the current is forced to follow the lines of subdivision, we see
that it will tend either to energize or de-energize the field, and this
will depend, other things being equal, upon the direction of the lines
of subdivision. If the subdivision be as indicated by the full lines in
Fig. 295, it is evident that if the current is of the same direction as
before, that is, from centre to periphery, its effect will be to
strengthen the field magnet; Whereas, if the subdivision be as indicated
by the dotted lines, the current generated will tend to weaken the
magnet. In the former case the machine will be capable of exciting
itself when the disc is rotated in the direction of arrow D; in the
latter case the direction of rotation must be reversed. Two such discs
may be combined, however, as indicated, the two discs rotating in
opposite fields, and in the same or opposite direction.

[Illustration: FIG. 295.]

[Illustration: FIG. 296.]

Similar disposition may, of course, be made in a type of machine in
which, instead of a disc, a cylinder is rotated. In such unipolar
machines, in the manner indicated, the usual field coils and poles may
be omitted and the machine may be made to consist only of a cylinder or
of two discs enveloped by a metal casting.

Instead of subdividing the disc or cylinder spirally, as indicated in
Fig. 295, it is more convenient to interpose one or more turns between
the disc and the contact ring on the periphery, as illustrated in Fig.
296.

A Forbes dynamo may, for instance, be excited in such a manner. In the
experience of the writer it has been found that instead of taking the
current from two such discs by sliding contacts, as usual, a flexible
conducting belt may be employed to advantage. The discs are in such case
provided with large flanges, affording a very great contact surface. The
belt should be made to bear on the flanges with spring pressure to take
up the expansion. Several machines with belt contact were constructed by
the writer two years ago, and worked satisfactorily; but for want of
time the work in that direction has been temporarily suspended. A number
of features pointed out above have also been used by the writer in
connection with some types of alternating current motors.




PART IV.

APPENDIX.--EARLY PHASE MOTORS AND THE TESLA MECHANICAL AND ELECTRICAL
OSCILLATOR.




CHAPTER XLII.

MR. TESLA'S PERSONAL EXHIBIT AT THE WORLD'S FAIR.

While the exhibits of firms engaged in the manufacture of electrical
apparatus of every description at the Chicago World's Fair, afforded the
visitor ample opportunity for gaining an excellent knowledge of the
state of the art, there were also numbers of exhibits which brought out
in strong relief the work of the individual inventor, which lies at the
foundation of much, if not all, industrial or mechanical achievement.
Prominent among such personal exhibits was that of Mr. Tesla, whose
apparatus occupied part of the space of the Westinghouse Company, in
Electricity Building.

This apparatus represented the results of work and thought covering a
period of ten years. It embraced a large number of different alternating
motors and Mr. Tesla's earlier high frequency apparatus. The motor
exhibit consisted of a variety of fields and armatures for two, three
and multiphase circuits, and gave a fair idea of the gradual evolution
of the fundamental idea of the rotating magnetic field. The high
frequency exhibit included Mr. Tesla's earlier machines and disruptive
discharge coils and high frequency transformers, which he used in his
investigations and some of which are referred to in his papers printed
in this volume.

Fig. 297 shows a view of part of the exhibits containing the motor
apparatus. Among these is shown at A a large ring intended to exhibit
the phenomena of the rotating magnetic field. The field produced was
very powerful and exhibited striking effects, revolving copper balls and
eggs and bodies of various shapes at considerable distances and at great
speeds. This ring was wound for two-phase circuits, and the winding was
so distributed that a practically uniform field was obtained. This ring
was prepared for Mr. Tesla's exhibit by Mr. C. F. Scott, electrician of
the Westinghouse Electric and Manufacturing Company.

[Illustration: FIG. 297.]

A smaller ring, shown at B, was arranged like the one exhibited at A but
designed especially to exhibit the rotation of an armature in a rotating
field. In connection with these two rings there was an interesting
exhibit shown by Mr. Tesla which consisted of a magnet with a coil, the
magnet being arranged to rotate in bearings. With this magnet he first
demonstrated the identity between a rotating field and a rotating
magnet; the latter, when rotating, exhibited the same phenomena as the
rings when they were energized by currents of differing phase. Another
prominent exhibit was a model illustrated at C which is a two-phase
motor, as well as an induction motor and transformer. It consists of a
large outer ring of laminated iron wound with two superimposed,
separated windings which can be connected in a variety of ways. This is
one of the first models used by Mr. Tesla as an induction motor and
rotating transformer. The armature was either a steel or wrought iron
disc with a closed coil. When the motor was operated from a two phase
generator the windings were connected in two groups, as usual. When used
as an induction motor, the current induced in one of the windings of the
ring was passed through the other winding on the ring and so the motor
operated with only two wires. When used as a transformer the outer
winding served, for instance, as a secondary and the inner as a primary.
The model shown at D is one of the earliest rotating field motors,
consisting of a thin iron ring wound with two sets of coils and an
armature consisting of a series of steel discs partly cut away and
arranged on a small arbor.

At E is shown one of the first rotating field or induction motors used
for the regulation of an arc lamp and for other purposes. It comprises a
ring of discs with two sets of coils having different self-inductions,
one set being of German silver and the other of copper wire. The
armature is wound with two closed-circuited coils at right angles to
each other. To the armature shaft are fastened levers and other devices
to effect the regulation. At F is shown a model of a magnetic lag motor;
this embodies a casting with pole projections protruding from two coils
between which is arranged to rotate a smooth iron body. When an
alternating current is sent through the two coils the pole projections
of the field and armature within it are similarly magnetized, and upon
the cessation or reversal of the current the armature and field repel
each other and rotation is produced in this way. Another interesting
exhibit, shown at G, is an early model of a two field motor energized by
currents of different phase. There are two independent fields of
laminated iron joined by brass bolts; in each field is mounted an
armature, both armatures being on the same shaft. The armatures were
originally so arranged as to be placed in any position relatively to
each other, and the fields also were arranged to be connected in a
number of ways. The motor has served for the exhibition of a number of
features; among other things, it has been used as a dynamo for the
production of currents of any frequency between wide limits. In this
case the field, instead of being energized by direct current, was
energized by currents differing in phase, which produced a rotation of
the field; the armature was then rotated in the same or in opposite
direction to the movement of the field; and so any number of
alternations of the currents induced in the armature, from a small to a
high number, determined by the frequency of the energizing field coils
and the speed of the armature, was obtained.

[Illustration: FIG. 298.]

The models H, I, J, represent a variety of rotating field, synchronous
motors which are of special value in long distance transmission work.
The principle embodied in these motors was enunciated by Mr. Tesla in
his lecture before the American Institute of Electrical Engineers, in
May, 1888[17]. It involves the production of the rotating field in one
of the elements of the motor by currents differing in phase and
energizing the other element by direct currents. The armatures are of
the two and three phase type. K is a model of a motor shown in an
enlarged view in Fig. 298. This machine, together with that shown in
Fig. 299, was exhibited at the same lecture, in May, 1888. They were the
first rotating field motors which were independently tested, having for
that purpose been placed in the hands of Prof. Anthony in the winter of
1887-88. From these tests it was shown that the efficiency and output of
these motors was quite satisfactory in every respect.

  [17] See Part I, Chap. III, page 9.

[Illustration: FIG. 299.]

It was intended to exhibit the model shown in Fig. 299, but it was
unavailable for that purpose owing to the fact that it was some time ago
handed over to the care of Prof. Ayrton in England. This model was
originally provided with twelve independent coils; this number, as Mr.
Tesla pointed out in his first lecture, being divisible by two and
three, was selected in order to make various connections for two and
three-phase operations, and during Mr. Tesla's experiments was used in
many ways with from two to six phases. The model, Fig. 298, consists of
a magnetic frame of laminated iron with four polar projections between
which an armature is supported on brass bolts passing through the frame.
A great variety of armatures was used in connection with these two and
other fields. Some of the armatures are shown in front on the table,
Fig. 297, and several are also shown enlarged in Figs. 300 to 310. An
interesting exhibit is that shown at L, Fig. 297. This is an armature of
hardened steel which was used in a demonstration before the Society of
Arts in Boston, by Prof. Anthony. Another curious exhibit is shown
enlarged in Fig. 301. This consists of thick discs of wrought iron
placed lengthwise, with a mass of copper cast around them. The discs
were arranged longitudinally to afford an easier starting by reason of
the induced current formed in the iron discs, which differed in phase
from those in the copper. This armature would start with a single
circuit and run in synchronism, and represents one of the earliest types
of such an armature. Fig. 305 is another striking exhibit. This is one
of the earliest types of an armature with holes beneath the periphery,
in which copper conductors are imbedded. The armature has eight closed
circuits and was used in many different ways. Fig. 304 is a type of
synchronous armature consisting of a block of soft steel wound with a
coil closed upon itself. This armature was used in connection with the
field shown in Fig. 298 and gave excellent results.

[Illustration: FIG. 300.]

[Illustration: FIG. 301.]

[Illustration: FIG. 302.]

[Illustration: FIG. 303.]

[Illustration: FIG. 304.]

[Illustration: FIG. 305.]

[Illustration: FIG. 306.]

[Illustration: FIG. 307.]

[Illustration: FIG. 308.]

[Illustration: FIG. 309.]

[Illustration: FIG. 310.]

Fig. 302 represents a synchronous armature with a large coil around a
body of iron. There is another very small coil at right angles to the
first. This small coil was used for the purpose of increasing the
starting torque and was found very effective in this connection. Figs.
306 and 308 show a favorite construction of armature; the iron body is
made up of two sets of discs cut away and placed at right angles to each
other, the interstices being wound with coils. The one shown in Fig. 308
is provided with an additional groove on each of the projections formed
by the discs, for the purpose of increasing the starting torque by a
wire wound in these projections. Fig. 307 is a form of armature
similarly constructed, but with four independent coils wound upon the
four projections. This armature was used to reduce the speed of the
motor with reference to that of the generator. Fig. 300 is still another
armature with a great number of independent circuits closed upon
themselves, so that all the dead points on the armature are done away
with, and the armature has a large starting torque. Fig. 303 is another
type of armature for a four-pole motor but with coils wound upon a
smooth surface. A number of these armatures have hollow shafts, as they
have been used in many ways. Figs. 309 and 310 represent armatures to
which either alternating or direct current was conveyed by means of
sliding rings. Fig. 309 consists of a soft iron body with a single coil
wound around it, the ends of the coil being connected to two sliding
rings to which, usually, direct current was conveyed. The armature shown
in Fig. 310 has three insulated rings on a shaft and was used in
connection with two or three phase circuits.

All these models shown represent early work, and the enlarged engravings
are made from photographs taken early in 1888. There is a great number
of other models which were exhibited, but which are not brought out
sharply in the engraving, Fig. 297. For example at M is a model of a
motor comprising an armature with a hollow shaft wound with two or three
coils for two or three-phase circuits; the armature was arranged to be
stationary and the generating circuits were connected directly to the
generator. Around the armature is arranged to rotate on its shaft a
casting forming six closed circuits. On the outside this casting was
turned smooth and the belt was placed on it for driving with any desired
appliance. This also is a very early model.

On the left side of the table there are seen a large variety of models,
N, O, P, etc., with fields of various shapes. Each of these models
involves some distinct idea and they all represent gradual development
chiefly interesting as showing Mr. Tesla's efforts to adapt his system
to the existing high frequencies.

On the right side of the table, at S, T, are shown, on separate
supports, larger and more perfected armatures of commercial motors, and
in the space around the table a variety of motors and generators
supplying currents to them was exhibited.

The high frequency exhibit embraced Mr. Tesla's first original apparatus
used in his investigations. There was exhibited a glass tube with one
layer of silk-covered wire wound at the top and a copper ribbon on the
inside. This was the first disruptive discharge coil constructed by him.
At U is shown the disruptive discharge coil exhibited by him in his
lecture before the American Institute of Electrical Engineers, in May,
1891.[18] At V and W are shown some of the first high frequency
transformers. A number of various fields and armatures of small models
of high frequency apparatus as shown at X and Y, and others not visible
in the picture, were exhibited. In the annexed space the dynamo then
used by Mr. Tesla at Columbia College was exhibited; also another form
of high frequency dynamo used.

  [18] See Part II, Chap. XXVI., page 145.

[Illustration: FIG. 311.]

In this space also was arranged a battery of Leyden jars and his large
disruptive discharge coil which was used for exhibiting the light
phenomena in the adjoining dark room. The coil was operated at only a
small fraction of its capacity, as the necessary condensers and
transformers could not be had and as Mr. Tesla's stay was limited to one
week; notwithstanding, the phenomena were of a striking character. In
the room were arranged two large plates placed at a distance of about
eighteen feet from each other. Between them were placed two long tables
with all sorts of phosphorescent bulbs and tubes; many of these were
prepared with great care and marked legibly with the names which would
shine with phosphorescent glow. Among them were some with the names of
Helmholtz, Faraday, Maxwell, Henry, Franklin, etc. Mr. Tesla had also
not forgotten the greatest living poet of his own country, Zmaj Jovan;
two or three were prepared with inscriptions, like "Welcome,
Electricians," and produced a beautiful effect. Each represented some
phase of this work and stood for some individual experiment of
importance. Outside the room was the small battery seen in Fig. 311, for
the exhibition of some of the impedance and other phenomena of interest.
Thus, for instance, a thick copper bar bent in arched form was provided
with clamps for the attachment of lamps, and a number of lamps were kept
at incandescence on the bar; there was also a little motor shown on the
table operated by the disruptive discharge.

As will be remembered by those who visited the Exposition, the
Westinghouse Company made a line exhibit of the various commercial
motors of the Tesla system, while the twelve generators in Machinery
Hall were of the two-phase type constructed for distributing light and
power. Mr. Tesla, also exhibited some models of his oscillators.




CHAPTER XLIII.

THE TESLA MECHANICAL AND ELECTRICAL OSCILLATORS.


On the evening of Friday, August 25, 1893, Mr. Tesla delivered a lecture
on his mechanical and electrical oscillators, before the members of the
Electrical Congress, in the hall adjoining the Agricultural Building, at
the World's Fair, Chicago. Besides the apparatus in the room, he
employed an air compressor, which was driven by an electric motor.

Mr. Tesla was introduced by Dr. Elisha Gray, and began by stating that
the problem he had set out to solve was to construct, first, a mechanism
which would produce oscillations of a perfectly constant period
independent of the pressure of steam or air applied, within the widest
limits, and also independent of frictional losses and load. Secondly, to
produce electric currents of a perfectly constant period independently
of the working conditions, and to produce these currents with mechanism
which should be reliable and positive in its action without resorting to
spark gaps and breaks. This he successfully accomplished in his
apparatus, and with this apparatus, now, scientific men will be provided
with the necessaries for carrying on investigations with alternating
currents with great precision. These two inventions Mr. Tesla called,
quite appropriately, a mechanical and an electrical oscillator,
respectively.

The former is substantially constructed in the following way. There is a
piston in a cylinder made to reciprocate automatically by proper
dispositions of parts, similar to a reciprocating tool. Mr. Tesla
pointed out that he had done a great deal of work in perfecting his
apparatus so that it would work efficiently at such high frequency of
reciprocation as he contemplated, but he did not dwell on the many
difficulties encountered. He exhibited, however, the pieces of a steel
arbor which had been actually torn apart while vibrating against a
minute air cushion.

With the piston above referred to there is associated in one of his
models in an independent chamber an air spring, or dash pot, or else he
obtains the spring within the chambers of the oscillator itself. To
appreciate the beauty of this it is only necessary to say that in that
disposition, as he showed it, no matter what the rigidity of the spring
and no matter what the weight of the moving parts, in other words, no
matter what the period of vibrations, the vibrations of the spring are
always isochronous with the applied pressure. Owing to this, the results
obtained with these vibrations are truly wonderful. Mr. Tesla provides
for an air spring of tremendous rigidity, and he is enabled to vibrate
big weights at an enormous rate, considering the inertia, owing to the
recoil of the spring. Thus, for instance, in one of these experiments,
he vibrates a weight of approximately 20 pounds at the rate of about 80
per second and with a stroke of about 7/8 inch, but by shortening the
stroke the weight could be vibrated many hundred times, and has been, in
other experiments.

To start the vibrations, a powerful blow is struck, but the adjustment
can be so made that only a minute effort is required to start, and, even
without any special provision it will start by merely turning on the
pressure suddenly. The vibration being, of course, isochronous, any
change of pressure merely produces a shortening or lengthening of the
stroke. Mr. Tesla showed a number of very clear drawings, illustrating
the construction of the apparatus from which its working was plainly
discernible. Special provisions are made so as to equalize the pressure
within the dash pot and the outer atmosphere. For this purpose the
inside chambers of the dash pot are arranged to communicate with the
outer atmosphere so that no matter how the temperature of the enclosed
air might vary, it still retains the same mean density as the outer
atmosphere, and by this means a spring of constant rigidity is obtained.
Now, of course, the pressure of the atmosphere may vary, and this would
vary the rigidity of the spring, and consequently the period of
vibration, and this feature constitutes one of the great beauties of the
apparatus; for, as Mr. Tesla pointed out, this mechanical system acts
exactly like a string tightly stretched between two points, and with
fixed nodes, so that slight changes of the tension do not in the least
alter the period of oscillation.

The applications of such an apparatus are, of course, numerous and
obvious. The first is, of course, to produce electric currents, and by a
number of models and apparatus on the lecture platform, Mr. Tesla showed
how this could be carried out in practice by combining an electric
generator with his oscillator. He pointed out what conditions must be
observed in order that the period of vibration of the electrical system
might not disturb the mechanical oscillation in such a way as to alter
the periodicity, but merely to shorten the stroke. He combines a
condenser with a self-induction, and gives to the electrical system the
same period as that at which the machine itself oscillates, so that both
together then fall in step and electrical and mechanical resonance is
obtained, and maintained absolutely unvaried.

Next he showed a model of a motor with delicate wheelwork, which was
driven by these currents at a constant speed, no matter what the air
pressure applied was, so that this motor could be employed as a clock.
He also showed a clock so constructed that it could be attached to one
of the oscillators, and would keep absolutely correct time. Another
curious and interesting feature which Mr. Tesla pointed out was that,
instead of controlling the motion of the reciprocating piston by means
of a spring, so as to obtain isochronous vibration, he was actually able
to control the mechanical motion by the natural vibration of the
electro-magnetic system, and he said that the case was a very simple
one, and was quite analogous to that of a pendulum. Thus, supposing we
had a pendulum of great weight, preferably, which would be maintained in
vibration by force, periodically applied; now that force, no matter how
it might vary, although it would oscillate the pendulum, would have no
control over its period.

Mr. Tesla also described a very interesting phenomenon which he
illustrated by an experiment. By means of this new apparatus, he is able
to produce an alternating current in which the E. M. F. of the impulses
in one direction preponderates over that of those in the other, so that
there is produced the effect of a direct current. In fact he expressed
the hope that these currents would be capable of application in many
instances, serving as direct currents. The principle involved in this
preponderating E. M. F. he explains in this way: Suppose a conductor is
moved into the magnetic field and then suddenly withdrawn. If the
current is not retarded, then the work performed will be a mere
fractional one; but if the current is retarded, then the magnetic field
acts as a spring. Imagine that the motion of the conductor is arrested
by the current generated, and that at the instant when it stops to move
into the field, there is still the maximum current flowing in the
conductor; then this current will, according to Lenz's law, drive the
conductor out of the field again, and if the conductor has no
resistance, then it would leave the field with the velocity it entered
it. Now it is clear that if, instead of simply depending on the current
to drive the conductor out of the field, the mechanically applied force
is so timed that it helps the conductor to get out of the field, then it
might leave the field with higher velocity than it entered it, and thus
one impulse is made to preponderate in E. M. F. over the other.

With a current of this nature, Mr. Tesla energized magnets strongly, and
performed many interesting experiments bearing out the fact that one of
the current impulses preponderates. Among them was one in which he
attached to his oscillator a ring magnet with a small air gap between
the poles. This magnet was oscillated up and down 80 times a second. A
copper disc, when inserted within the air gap of the ring magnet, was
brought into rapid rotation. Mr. Tesla remarked that this experiment
also seemed to demonstrate that the lines of flow of current through a
metallic mass are disturbed by the presence of a magnet in a manner
quite independently of the so-called Hall effect. He showed also a very
interesting method of making a connection with the oscillating magnet.
This was accomplished by attaching to the magnet small insulated steel
rods, and connecting to these rods the ends of the energizing coil. As
the magnet was vibrated, stationary nodes were produced in the steel
rods, and at these points the terminals of a direct current source were
attached. Mr. Tesla also pointed out that one of the uses of currents,
such as those produced in his apparatus, would be to select any given
one of a number of devices connected to the same circuit by picking out
the vibration by resonance. There is indeed little doubt that with Mr.
Tesla's devices, harmonic and synchronous telegraphy will receive a
fresh impetus, and vast possibilities are again opened up.

Mr. Tesla was very much elated over his latest achievements, and said
that he hoped that in the hands of practical, as well as scientific men,
the devices described by him would yield important results. He laid
special stress on the facility now afforded for investigating the effect
of mechanical vibration in all directions, and also showed that he had
observed a number of facts in connection with iron cores.

[Illustration: FIG. 312.]

The engraving, Fig. 312, shows, in perspective, one of the forms of
apparatus used by Mr. Tesla in his earlier investigations in this field
of work, and its interior construction is made plain by the sectional
view shown in Fig. 313. It will be noted that the piston P is fitted
into the hollow of a cylinder C which is provided with channel ports
O O, and _I_, extending all around the inside surface. In this
particular apparatus there are two channels O O for the outlet of the
working fluid and one, _I_, for the inlet. The piston P is provided with
two slots S S' at a carefully determined distance, one from the other.
The tubes T T which are screwed into the holes drilled into the piston,
establish communication between the slots S S' and chambers on each side
of the piston, each of these chambers connecting with the slot which is
remote from it. The piston P is screwed tightly on a shaft A which
passes through fitting boxes at the end of the cylinder C. The boxes
project to a carefully determined distance into the hollow of the
cylinder C, thus determining the length of the stroke.

Surrounding the whole is a jacket J. This jacket acts chiefly to
diminish the sound produced by the oscillator and as a jacket when the
oscillator is driven by steam, in which case a somewhat different
arrangement of the magnets is employed. The apparatus here illustrated
was intended for demonstration purposes, air being used as most
convenient for this purpose.

A magnetic frame M M is fastened so as to closely surround the
oscillator and is provided with energizing coils which establish two
strong magnetic fields on opposite sides. The magnetic frame is made up
of thin sheet iron. In the intensely concentrated field thus produced,
there are arranged two pairs of coils H H supported in metallic frames
which are screwed on the shaft A of the piston and have additional
bearings in the boxes B B on each side. The whole is mounted on a
metallic base resting on two wooden blocks.

[Illustration: FIG. 313.]

The operation of the device is as follows: The working fluid being
admitted through an inlet pipe to the slot I and the piston being
supposed to be in the position indicated, it is sufficient, though not
necessary, to give a gentle tap on one of the shaft ends protruding
from the boxes B. Assume that the motion imparted be such as to move the
piston to the left (when looking at the diagram) then the air rushes
through the slot S' and tube T into the chamber to the left. The
pressure now drives the piston towards the right and, owing to its
inertia, it overshoots the position of equilibrium and allows the air to
rush through the slot S and tube T into the chamber to the right, while
the communication to the left hand chamber is cut off, the air of the
latter chamber escaping through the outlet O on the left. On the return
stroke a similar operation takes place on the right hand side. This
oscillation is maintained continuously and the apparatus performs
vibrations from a scarcely perceptible quiver amounting to no more than
1 of an inch, up to vibrations of a little over 3/8 of an inch,
according to the air pressure and load. It is indeed interesting to see
how an incandescent lamp is kept burning with the apparatus showing a
scarcely perceptible quiver.

To perfect the mechanical part of the apparatus so that oscillations are
maintained economically was one thing, and Mr. Tesla hinted in his
lecture at the great difficulties he had first encountered to accomplish
this. But to produce oscillations which would be of constant period was
another task of no mean proportions. As already pointed out, Mr. Tesla
obtains the constancy of period in three distinct ways. Thus, he
provides properly calculated chambers, as in the case illustrated, in
the oscillator itself; or he associates with the oscillator an air
spring of constant resilience. But the most interesting of all, perhaps,
is the maintenance of the constancy of oscillation by the reaction of
the electromagnetic part of the combination. Mr. Tesla winds his coils,
by preference, for high tension and associates with them a condenser,
making the natural period of the combination fairly approximating to the
average period at which the piston would oscillate without any
particular provision being made for the constancy of period under
varying pressure and load. As the piston with the coils is perfectly
free to move, it is extremely susceptible to the influence of the
natural vibration set up in the circuits of the coils H H. The
mechanical efficiency of the apparatus is very high owing to the fact
that friction is reduced to a minimum and the weights which are moved
are small; the output of the oscillator is therefore a very large one.

Theoretically considered, when the various advantages which Mr. Tesla
holds out are examined, it is surprising, considering the simplicity of
the arrangement, that nothing was done in this direction before. No
doubt many inventors, at one time or other, have entertained the idea of
generating currents by attaching a coil or a magnetic core to the piston
of a steam engine, or generating currents by the vibrations of a tuning
fork, or similar devices, but the disadvantages of such arrangements
from an engineering standpoint must be obvious. Mr. Tesla, however, in
the introductory remarks of his lecture, pointed out how by a series of
conclusions he was driven to take up this new line of work by the
necessity of producing currents of constant period and as a result of
his endeavors to maintain electrical oscillation in the most simple and
economical manner.




INDEX.


Alternate Current Electrostatic Apparatus 392

Alternating Current Generators for High Frequency 152, 374, 224

Alternating Motors and Transformers 7

American Institute Electrical Engineers Lecture 145

Anthony, W. A., Tests of Tesla Motors 8

Apparatus for Producing High Vacua 276

Arc Lighting, Tesla Direct, System 451

Auxiliary Brush Regulation 438


Biography, Tesla 4

Brush, Anti-Sparking 432

Brush, Third, Regulation 438

Brush, Phenomena in High Vacuum 226


Carborundum Button for Tesla Lamps 140, 253

Commutator, Anti-Sparking 432

Combination of Synchronizing and Torque Motor 95

Condensers with Plates in Oil 418

Conversion with Disruptive Discharge 193, 204, 303

Current or Dynamic Electricity Phenomena 327


Direct Current Arc Lighting 451

Dischargers, Forms of 305

Disruptive Discharge Coil 207, 221

Disruptive Discharge Phenomena 212

Dynamos, Improved Direct Current 448


Early Phase Motors 477

Effects with High Frequency and High Potential Currents 119

Electrical Congress Lecture, Chicago. 486

Electric Resonance 340

Electric Discharges in Vacuum Tubes 396

Electrolytic Registering Meter 420

Eye, Observations on the 294


Flames, Electrostatic, Non-Consuming 166, 272

Forbes Unipolar Generator 468, 474

Franklin Institute Lecture 294


Generators, Pyromagnetic 429


High Potential, High Frequency:

  Brush Phenomena in High Vacuum 226
  Carborundum Buttons 140, 253
  Disruptive Discharge Phenomena 212
  Flames, Electrostatic, Non-Consuming 166, 272
  Impedance, Novel Phenomena 194, 338
  Lighting Lamps Through Body 359
  Luminous Effects with Gases 368
  "Massage" with Currents 394
  Motor with Single Wire 234, 330
  "No Wire" Motors 235
  Oil Insulation of Induction Coils 173, 221
  Ozone, Production of 171
  Phosphorescence 367
  Physiological Effects 162, 394
  Resonance 340
  Spinning Filament 168
  Streaming Discharges of High Tension Coil 155, 163
  Telegraphy without Wires 346


Impedance, Novel Phenomena 194, 338

Improvements in Unipolar Generators 465

Improved Direct Current Dynamos and Motors 448

Induction Motors 92

Institution Electrical Engineers Lecture 198


Lamps and Motor operated on a Single Wire 330

Lamps with Single Straight Fiber 183

Lamps containing only a Gas 188

Lamps with Refractory Button 177, 239, 360

Lamps for Simple Phosphorescence 187, 282, 364

Lecture, Tesla before:

 American Institute Electrical Engineers 145
 Royal Institution 124
 Institution Electrical Engineers 198
 Franklin Institute and National Electric Light Association 294
 Electrical Congress, Chicago 486

Lighting Lamps Through the Body 359

Light Phenomena with High Frequencies 349

Luminous Effects with Gases at Low-Pressure 368


"Magnetic Lag" Motor 67

"Massage" with Currents of High Frequency 394

Mechanical and Electrical Oscillators 486

Method of obtaining Direct from Alternating currents 409

Method of obtaining Difference of Phase by Magnetic Shielding 71

Motors:

  With Circuits of Different Resistance 79
  With Closed Conductors 9
  Combination of Synchronizing and Torque 95
  With Condenser in Armature Circuit 101
  With Condenser in one of the Field Circuits 106
  With Coinciding Maxima of Magnetic Effect in Armature and Field 83
  With "Current Lag" Artificially Secured 58
  Early Phase 477
  With Equal Magnetic Energies in Field and Armature 81
  Or Generator, obtaining Desired Speed of 36
  Improved Direct Current 448
  Induction 92
  "Magnetic Lag" 67
  "No Wire" 235
  With Phase Difference in Magnetization of Inner and Outer Parts
          of Core 88
  Regulator for Rotary Current 45
  Single Circuit, Self-starting Synchronizing 50
  Single Phase 76
  With Single Wire to Generator 234, 330
  Synchronizing 9
  Thermo-Magnetic 424
  Utilizing Continuous Current Generators 31


National Electric Light Association Lecture 294

"No Wire" Motor 235


Observations on the Eye 294

Oil, Condensers with Plates in 418

Oil Insulation of Induction Coils 173, 221

Oscillators, Mechanical and Electrical 486

Ozone, Production of 171

Phenomena Produced by Electrostatic Force 318

Phosphorescence and Sulphide of Zinc 367

Physiological Effects of High Frequency 162, 394

Polyphase Systems 26

Polyphase Transformer 109

Pyromagnetic Generators 429

Regulator for Rotary Current Motors 45

Resonance, Electric, Phenomena of 340

"Resultant Attraction" 7

Rotating Field Transformers 9

Rotating Magnetic Field 9

Royal Institution Lecture 124

Scope of Lectures 119

Single Phase Motor 76

Single Circuit, Self-Starting Synchronizing Motors 50

Spinning Filament Effects 168

Streaming Discharges of High Tension Coil 155, 163

Synchronizing Motors 9

Telegraphy without Wires 246

Transformer with Shield between Primary and Secondary 113

Thermo-Magnetic Motors 424

Thomson, J. J., on Vacuum Tubes 397, 402, 406

Thomson, Sir W., Current Accumulator 471

Transformers:

  Alternating 7
  Magnetic Shield 113
  Polyphase 109
  Rotating Field 9

Tubes:

  Coated with Yttria, etc. 187
  Coated with Sulphide of Zinc, etc. 290, 367

Unipolar Generators 465

Unipolar Generator, Forbes 468, 474

Yttria, Coated Tubes 187

Zinc, Tubes Coated with Sulphide of 367









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breaks occur. They are given here within a dashed border, in order to
call out their separate nature.

Minor errors, attributable to the printer, have been corrected. Please
see the transcriber’s note at the end of this text for details regarding
the handling of any textual issues encountered during its preparation.

There are many URLs in the text, given the topic, but it is unlikely
that any are still extant, given the publication date in 1995.

------------------------------------------------------------------------

                               NETWORLD!

                                        what people are
                                                 really
                                                    doing
                                                   on the
                                                  INTERNET,
                                                    and what
                                                    it means
                                                     to you

      DAVID H. ROTHMAN

          “A considerable achievement.”—William F. Buckley, Jr.


                                                 Current Events/Internet


          “A considerable achievement. You find yourself wanting to read
          _NetWorld!_ even if you have no thought of baptism into the
          great new scene.” —William F. Buckley, Jr.


    “David H. Rothman has done the best job yet of illustrating exactly
    how and why the Internet will change the texture of daily life. Most
    discussion of the information age is full of airy generalizations.
    _NetWorld!_ is full of specific, amusing, often racy illustrations
    of how people around the world have already put the Net’s
    possibilities to work. This is a very useful and entertaining book.”
    —James Fallows Washington editor of the _Atlantic Monthly_


Exploring Life on the Net


Praised by the _New York Times_ For his entertaining style, David H.
Rothman has written a lively, revealing, and sharp-eyed account of life
on the Net. Read how a handsome young librarian in Adelaide, Australia,
got engaged to a Kansas City woman he’d never met—except online.
Discover why net.censors and other interlopers could eventually cost
America billions of dollars. Learn how an Anglican priest uses the
Internet to “hear” confessions and help keep in touch with his flock.
From electronic libraries to the digitized cadaver of an executed
killer, _NetWorld!_ covers everything that’s happening on the Net.


Whether you surf nightly or know the Net only secondhand, _NetWorld!_
will shed new light on the cultural phenomenon that is engrossing
millions around the world.

Prima Publishing

------------------------------------------------------------------------

                               NetWorld!

                              What People
                              Are =Really=
                        Doing on the =Internet=,
                          and What It Means to
                                 =You=

    _David H. Rothman_








    PRIMA PUBLISHING

------------------------------------------------------------------------

                          _With 88s to Carly,
                           my dearest company
                       in life and on the ’Bahn._

© 1996 by David H. Rothman

All rights reserved. No part of this book may be reproduced or
transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or by any information storage or
retrieval system, without written permission from Prima Publishing,
except for the inclusion of quotations in a review.

PRIMA PUBLISHING and colophon are trademarks of Prima Communications,
Inc.

Cover design by the Dunlavey Studio

           Library of Congress Cataloging-in-Publication Data

Rothman, David H.
  Networld!: what people are really doing on the Internet, and what it
means to you/David H. Rothman.
    p. cm.
  Includes index.
  ISBN O-7615-0013-8
  1. Internet (Computer network) I. Title.
TK5105.875.I57R69 1995
004.6’7—dc20

                                                                 95-5287
                                                                   CIP

95 96 97 98 99 AA 10 9 8 7 6 5 4 3 2 1
Printed in the United States of America

How to Order:

Single copies may be ordered from Prima Publishing, P.O. Box 1260BK,
Rocklin, CA 95677; telephone (916) 632-4400. Quantity discounts are also
available. On your letterhead, include information concerning the
intended use of the books and the number of books you wish to purchase.

                                Contents

  _A Note to Visitors (and Natives)_                               _v_

  _Acknowledgments_                                              _vii_

  1    The Terrain                                                   1

  2    Business on the Net:
       From White Rabbit Toys to “Intel Inside”                     27

  3    EntertaiNet: A Few Musings on Net.Rock,
       Leonardo da Vinci and Bill Gates,
       Bianca’s Smut Shack, and David Letterman
       in Cyberspace                                                80

  4    Pulped Wood versus Electrons:
       Can the Print World Learn to Love the Net?                  105

  5    Wired Knowledge:
       When They Let a Murderer Loose on the Internet              172

  6    Governments and the Net:
       Making Sure Orwell Was Wrong                                208

  7    The Electronic Matchmaker                                   291

  _Notes_                                                        _327_

  _Index_                                                        _335_

                           A Note to Visitors
                             (and Natives)

Everyone in _NetWorld!_ is real, even me. Chapter 1 tells how to reach
some good people who let their electronic addresses go on the Web site
for this book.

In a few cases—most notably “Sue” and “Greg” in Chapter 7—I’ve guarded
my subjects’ privacy with aliases and changes of identifying details.
Asterisks show up after the first occurrences of their revised names.

Please note, too, that I’ve smoothed out people’s informal online prose
to accommodate the printed page. A “smiley” on the Net is a good quick
way to show a smile or frown; but I couldn’t think of anything uglier in
print than a series of symbols such as :-). So even in quotes, I’ve used
them sparingly.

I wish Mark Twain were alive and cruising the Internet at 28.8 kilobits
per second; I’d love to see how he’d have handled net.dialect.

                                                  David Rothman,
                                                  rothman@clark.net
                                                  Alexandria, Virginia

                            Acknowledgments

Alison, step to the front! Alison Andrukow, a graduate student at
Queen’s University in Kingston, Ontario, served as my chief researcher
on this project—discovering a number of goodies ranging from Bianca’s
Smut Shack to arcane, Net-related policy studies.

Jennifer Basye Sander, my editor at Prima Publishing, working with
associate acquisitions editor Alice Anderson and the project editor,
Steven Martin, provided many suggestions, as did the publisher, Ben
Dominitz. The latter promoted this book, so to speak, from _Digital
America_ to _Digital World_, and in time the title _NetWorld!_ also came
from Ben. Surprise, you guys! You thought you were getting a general
book on computer technology, but wisely you let me get caught up in the
Net. _Thanks!_

Bill Adler and Lisa Swayne of Adler and Robin Books, joined by Nick
Anis, agented this book. Nancy Daisywheel Breckenridge was the
transcriptionist.

Finally, I want to thank the many people who gave their time by way of
e-mail or otherwise. Lest I forget some important ones here, I won’t
list any names. But by way of the references in the book itself, readers
will learn the identities of many.




                                CHAPTER
                                  ONE

    The Terrain


A color photo lights up my computer screen when I hit the return key,
and, in big, bold Times Roman letters, I see the latest from the
Internet:

  _Playboy Is Traveling the Info Highway
  Looking for Women for a Special
  “Girls of the Net” Pictorial_

Sitting atop a pile of books, a most ungeekish model looks flawlessly
nubile, as if part of a virtual reality tableau conjured up for Hugh
Hefner himself. _Playboy’s_ message is clear: What counts isn’t mastery
of Telnet, Gopher, Lynx, or other Net voodoo. Candidates should mail or
e-mail “a recent full-length body photo in a two-piece bathing suit or
less and a clear face shot.”

The same day a famous hacker named Cliff Stoll goes on a Washington
radio station to promote his book _Silicon Snake Oil_, which says the
Internet steals too much time from true learning and life.

For better or worse—mostly better in my opinion, egalitarian that I
am—the Internet has Arrived.

A quarter-century ago scientists dreamed up a predecessor of the network
to let computers jabber to each other across the United States, even
after a nuclear attack. Fearless professors followed with electronic
talk on topics ranging from biology to poetry.

Now it’s as if _everyone_ is on the Internet—not just _Playboy_ but
_Penthouse_, some Arizona lawyers who love to inflict junk ads on the
innocent, a Florida manicurist, Democratic and Republican stalwarts,
thousands of college freshmen, punk teenagers, and elementary schoolers
in London, Singapore, Minnesota, Nova Scotia—you name it. In one way or
other, the Net ties in to smaller networks ranging from local, bulletin
board-style systems to America Online, CompuServe, Prodigy, Delphi,
GEnie, Bitnet, Bix, eWorld, and MCI Mail.

Fans of David Letterman and Jay Leno, the world’s most famous talk-show
rivals, are even duking it out online. The cyberspace section of
_Newsweek_ regularly lists the hottest attractions of the Internet—for
example, the best sites on the World Wide Web, the multimedia area where
you can see pictures and hear sound.

Hollywood is gambling on a movie called _The Net_, and _Time_ and
_Newsweek_ have done several cover stories. Could the _Time_ curse be at
work here? Is everything else downhill, now that the Net has landed on
The Cover? Not if you go by the stats. Internet demographers love to
squabble about the exact number of people on the Internet, but at the
very least, some 25-30 million can reach it by way of electronic mail;
and in a few years, if the braver prophets are right, hundreds of
millions may be wired in. For the snobs, of course, the old cachet is
gone. A humor columnist says the Net is like citizens band radio with
typing.

Is the Internet, then, about to become a 500,000-channel wasteland? Just
what are all these millions _really_ doing on the Net? Some politicians
would have you think that a disturbing number of Netfolks are busy
corrupting the morals of minors, and shouldn’t we ban smut from the
public areas of cyberspace? And if you believe some American security
bureaucrats, the Net might turn out to be a haven for spies and dope
dealers. “Shouldn’t Washington,” they more or less ask, “be able to
snoop on pervs and subversives who scramble their messages?”

The counterrevolution has begun, and I feel grouchy.

Everyone is trying to reinvent the Internet in his or her own image,
even if, with these changes, the Net would no longer be the Net. What’s
really pathetic is the ignorance of the would-be meddlers. Censoring the
Net would be about as successful as trying to dam the Pacific. The same
decentralization that made the Net more nuke-resistant, in the Cold War
days, makes it harder to control. And how can Washington sell the Net on
Fed-friendly chips for coded messages when scores of powerful encryption
products are on sale in Russia and the rest of Europe?

At the same time, certain writers are now attacking the Internet as Cold
and Heartless, or for other sins; some are even Pulling the Plug, at
least temporarily, to protect their delicate brains against Information
Overload.

“Don’t make me go back!” J. C. Hertz recalls telling her editors when
they wanted her to log back on the Net to wind down a book called
_Surfing the Internet_. “Please, don’t make me go back there.” Stephen
L. Talbott, a computer editor and author of _The Future Does Not
Compute_, proclaims that he “immediately felt very good” when he
Unplugged. Bill Henderson of the Push Cart Press says he’ll publish a
book with “cries from the heart about what electronics has done to
people.”[1.1]

Perhaps a new literary genre is aborning—that of the Snubbites, the new
Luddites[1.2] who feel all Netted Up. The definition might go something
like this:

    _Snubbite:—n. One who, partly out of snobbery, partly out of
    boredom, partly out of sheer contrariness, snubs the computer
    technology that could help millions of others._

A typical Snubbite is upper-middle class and very possibly Ivy League.
Snubbites could afford computer and Internet connections—or more likely
enjoyed them at others’ expense—years before average people were even
allowed on the Net. Often Snubbites live near large libraries or can
catch up with books easily enough in other ways. Snubbites may have
already used the Net to help stock up on their quota of friends and
professional contacts. Most Snubbites are harmless and even charmingly
eccentric; they worry me only when they start confusing their own needs
and non-needs with those of society at large.

Cliff Stoll himself is very much on the Internet (“I still love my
networked community”) even now; to this day, I suspect, he truly enjoys
seeing people home-brew their own machines. But in stretches of his book
he could almost be mistaken for a Snubbite anyway, based on sheer
fervor. “It is an overpromoted, hollow world, devoid of warmth and human
kindness,” Stoll writes of cyberspace, and goes on to say that nets
address “few social needs or business concerns” and threaten “precious
parts of our society, including schools, libraries, and social
institutions.” He complains, “No birds sing.”

Have I been hallucinating? The Internet isn’t Woodstock, the Vatican, or
an aviary, but it is bringing together people for religion, education,
business, love, and suicide prevention. Just what is Stoll writing
about? Does the Net have an evil twin? Jews, Moslems, Lutherans, and
Catholics—they are all using the Net to exchange prayers or electronic
newsletters. Up in Canada an Anglican priest will even take confessions
via e-mail. I doubt he’d agree with the author of _Snake Oil_.

Nor, I suspect, would the members of Walkers in Darkness. Walkers is a
mailing list for people with chronic depression, and each week more than
300 messages whiz across the Net from Australia to Israel, from South
Africa to California. I’m not depressed, but someone close to me is, and
she spends hour after hour with her laptop, gazing at the blue-and-white
on the screen, reading scores of messages, keeping up with the gossip
about people and drugs, wondering what she would do without her Net
connection. Being depressed is like kayaking or hang gliding: You won’t
die immediately if you skip the homework, but in a pinch you’ll stand a
much better chance if you’ve gone far beyond the basics. Walkers is in
the grand tradition of the Net. Its members don’t blindingly trust
authority figures—their own shrinks—and they are reaching out to other
patients and to an online psychiatrist. Tell us, Ivan, some Walkers ask,
is Parnate as good a drug as it’s cracked up to be? What about Nardil?
Can you take it without your body swelling up?

“Ivan” is a well-credentialed psychopharmacologist in New York City who
helps out for free. Dr. Ivan Goldberg doesn’t prescribe drugs for people
online, but he _will_ report his own experiences with them after many
years of practice. He has a knack for coming up with angles that
patients’ own doctors might miss. After months on Prozac, a man found
his work slipping. Ivan Goldberg told him of a new way—successful here,
it turns out—to treat the problem.

Goldberg is online two hours a day “as a way of paying back for the
thirty-plus good years I have had from my work with depressed
people.”[1.3] After several years on the Net helping virtual support
groups, he has won the respect of hundreds and perhaps even thousands.

Still, Walkers compare notes with each other and don’t accept even Ivan
Goldberg’s opinions automatically. Just as if they were talking over the
office watercooler, they weigh the validity of the information
themselves. But what a collection of facts! When a new antidepressant
shows up in Canada or the United Kingdom, Walkers learn about it many
weeks before the news reaches the daily papers in the States, assuming
that word makes their daily newspapers at all.

Many of the best conversations, however, aren’t about drugs or the
merits or perils of electroconvulsive shock treatments. They’re about
other Walkers. Remember the gay Walker in Iowa who was so quick to
welcome newcomers and answer questions? Well, here’s his obit: _Died of
complications from diabetes_. How about the fellow on the East Coast,
the programmer who never logs on with a name? Is he okay, after his last
suicide attempt? Is somebody going to drop by to visit him in the
hospital? What about such-and-such’s cat? How’s your new girlfriend? Is
your landlord being reasonable? The questions and answers fly across the
wires. Walkers may not be as famous a virtual community as The WELL,
Echo, and similar bulletin board systems with Net and media connections,
but it’s hardly as if the luminaries of those places enjoy a monopoly on
Caring.

Later that morning I hear Cliff Stoll push his book on WAMU radio. It’s
a slaughter; the call-ins run against him by at least five to one. I
even feel a little sorry for him until I remember that the technophobes
at many bookstores may outnumber the technophiles. The full title of the
book is _Silicon Snake Oil: Second Thoughts on the Information Highway_,
and it should be just the ticket for Luddites and Snubbites with spare
change. I myself have Second Thoughts about his Second Thoughts. Early
on in his book he says: “I look forward to the time when our Internet
reaches into every town and trailer park.” But his true emphasis comes
through. Just how much of a technopopulist is he in the end when he
claims that networks will “isolate us from one another” and “work
against literacy and creativity?”

What’s really freaky is that a woman from Walkers or a similar
discussion group—out of all the thousands on the Net—calls up _The Diane
Rehm Show_ and ever so politely shreds the arguments that Stoll has made
in _Oil_. A few years ago he wrote _The Cuckoo’s Egg_, a wonderful book
about his battles against errant hackers, and parts of _Snake Oil_ do
ring true, but oh how wrong he is about the more cosmic issues.
Confronted with the Walkers-style example, Stoll acknowledges that, yes,
maybe the Net could be of use to people who need support. After all, the
very anonymity he’s assailed can work in favor of honest dialogue.
Exactly. One of the glories of Walkers, however, is that depressed
people can be as open or nameless as they want. What’s more, they can
even go Face to Face. Several Walkers near me, for example, will spend
hours and hours talking in person with others dogged by this scourge of
Lincoln and Churchill.

Dave Harmon is the man behind the Walkers list. He’s a
twenty-eight-year-old Harvard grad, bearded, bespectacled, and a little
on the heavy side, as he describes it. I learn that he works as a
programmer for a company that writes software to use with mice—the
computer kind. His depression is moderate. Come the middle of the night,
he may wake up in a cold sweat; he can also suffer flagging energy.

Several years ago Harmon was crouched in a Boston bus shelter, enjoying
a break from a crowded but rainy New Year’s Eve celebration, when he
took out a notebook and wrote a poem. “I am the Walker in Darkness,” it
read in part, “I am the bringer of light.” The next day Harmon called
the company that had hooked him into the Internet—he wanted to start a
list for depressed people interested in art and magic. “The thing that
makes the Net so powerful is that you don’t have to get into a big deal
to start a minor newsgroup or a mailing list.” The newsgroups and the
mailing lists can precisely reflect Netfolks’ interests, loves, and
fears—much more closely than, say, CBS or the _New York Times_, or even
niche programs on cable.

Oklahoma City and the
Ban-the-Bomb-Manual Panic

A citation for _The Terrorist’s Handbook_ popped up on my screen a
minute after I started a search of the World Wide Web under the word
“explosives.” I apparently would be able to make “book bombs,”
“lightbulb bombs,” “phone bombs.”

Trying to retrieve the _Handbook_ some weeks later, I read the
following: “Are you sure this resource exists?” Cute. The heat is on.
_Handbook_-style items caught the attention of the U.S. Senate after
sickos blew up a federal building in Oklahoma City and killed 160
people. The response in effect was: “Ban the bomb manuals—from the Net
and otherwise!” and as of this writing, it looked as if such sentiments
might end up as law. Still, a little problem arose in the case of _The
Terrorist’s Handbook_ on the Net. The material was coming to me from
Lysator, a respected academic computer society at Linköping University
in Linköping, _Sweden_. Last I knew, the U.S. Senate did not enjoy
jurisdiction over its counterparts in Stockholm.

The Swedish computer that stored _The Terrorist’s Handbook_, however,
contains megabyte after megabyte of valuable material on computing and
other subjects, and the electronic librarians didn’t want to anger the
university. So out of prudence, they voluntarily removed the bomb manual
after hysterical stories appeared in the press. The _Handbook_ wasn’t
worth the fuss.

Perhaps in other cases Washington will use diplomacy with other
countries to unplug _Handbook_-style items. But no one should count on
this approach working in the end. Inevitably the same material will be
secretly making the rounds of obscure electronic bulletin board systems,
as opposed to the Net itself. As if that isn’t enough, Washington has
unwittingly given out instructions for bomb-makers by way of the
tax-financed _Blaster’s Handbook_ from the Forestry Service in the U.S.
Department of Agriculture. Even _The Encyclopedia Britannica_ has
printed material on explosive making.

Most disturbing of all, Constitutional issues arise here. We don’t need
the government to restrain free speech. As writer Brock N. Meeks wrote
in his _CyberWire Dispatch_ newsletter, Senator Dianne Feinstein’s
proposal was “a break in the dike.” It was “the trickle that could
become a river of regulatory hammers meant to turn the rough-and-tumble,
open and free-flowing online discourse into something with all the
appeal and intellectual acumen of tofu.”

Newsgroups are a bit like local bulletin board systems except that some
newsgroups reach hundreds of thousands of people around the world.
Mailing lists are more intimate than newsgroups since you usually need
to sign up for them electronically before you receive the messages.

“The funny thing,” Harmon says of freshly created mailing lists, “is
that you never know what will result. What I found was that most
depressed people couldn’t produce that much art and mysticism, but they
were interested in supporting each other, and I looked at that and let
it go on its own.”

A seventy-eight-year-old widow in the American South discovered Harmon’s
list. She was the first in her family, after several generations of
mental illness, to seek psychiatric help. People from Singapore have
popped up, too, reporting how they were stigmatized as lazy by people
unable to understand the energy-sapping qualities of the disease.
Walkers tell of spouses complaining about the loss of sex drive from
depression or medications. Simply put, Harmon’s list has not just helped
people cope with a disease, but it has also helped those who can’t
understand it. And as shown by the Singaporean example, geography has
been inconsequential for the most part. “When you’re depressed,” Harmon
says, “it doesn’t matter where you’re from, you’re still depressed.”

What’s more, Walkers can log on as often or seldom as they want.
Frequently the depressed feel all “peopled up,” so they may flee into
their rooms and close the blinds when visitors approach. But with
Walkers messages, all they need do is press the delete key. The Internet
isn’t just a medium of special benefit to the deaf; it’s also one for
the seriously depressed, many of whom, if made Netless, might try to do
without _any_ company offline.

As with thousands of other Net lists, people come and go, some of them
overwhelmed by the sheer volume of messages; Stoll is right to
characterize the Internet as like trying to drink water from a fire
hydrant. But a core of stalwarts remain enthusiastically on Walkers, and
along with Harmon and Goldberg, they’re rather small-townish in
cyberspace in the best of ways. I ask about the East Coast Walker with
suicidal tendencies. Harmon says that by the time the supportive
messages reached the man, the programmer had already called 911 and gone
to the hospital to have his stomach pumped.

But, yes, Harmon says, Walkers has indeed saved lives. “A more usual
situation is that someone is considering suicide and issues an appeal to
Walkers for help. They’ll say something to the effect that ‘It’s not
worth it, and nothing I do ever works, and I’m probably bothering you
with this note.’ People respond to it and sometime call the person by
phone if the number is available.” If the number isn’t, Harmon and other
Netheads will try to use their knowledge of the Internet to track it
down. “We don’t breach privacy unless there really is a suicide threat,
and sometimes people’s accounts may be on services where we can’t find
them. More usually, various people may send their own phone numbers
either privately or to someone or to the list, so that other members can
reach them.

“The Internet,” he cautions, “is _not_ always a fast-rescuer—you may be
lucky to get same-day service. In the programmer’s case his note didn’t
even get _to_ my list for an hour, much less get sent out to all the
members. _I_ found out about his note by getting a midnight phone call!”

Still, Harmon sees the Net as a godsend for ongoing support and as a
crisis aid even if the help isn’t always immediate. Goldberg agrees:
“It’s mobilized people to all kinds of interventions.”[1.4]

“I’m sitting here with a knife in my hand,” wrote a community college
student asking for support from Walkers. “Don’t worry, I’m not going to
kill myself—just hurt myself a little. I just feel as though I deserve
pain.” She went on to tell how she had been in the National Honor
Society in high school, gone on to an honors program at Loyola
University for several years, then had been forced to leave. “I used to
be strong, brilliant, and ambitious and now I am stupid and manic
depressive. It just hurts so much. So I guess that’s why I’m cutting on
my wrists tonight.” She told me when I wrote to ask about her
condition—improved—that “I would be lost without Walkers.”

A near-suicide in Santa Clara, California, aided by the newsgroup
alt.support.depression, recalls: “I was so close it was amazing.”
Medical debts had overwhelmed him. He was a single father and his boss
had put him on probation after child care gobbled up too much work time.
In tears he began his note: “It doesn’t really matter any more.” A New
York woman saw the note and begged people online to help. Hundreds of
messages came over the Net from as far as Japan. Tracked down despite
his unsigned post, the California man received help not only from a
colleague at work but also from police. “Something snapped,” he recalls,
“and I just realized that there were a lot of people there who
cared.”[1.5]

Madness, another self-help group on the Net, is a mailing list for
people who suffer drastic mood swings, hear voices, and see visions.
Now, says Sylvia Caras, who runs the list, they can use the Net to carry
on a dialogue with federal mental health officials. The Net offers a
very _real_ voice for those the world might otherwise ignore.

I could go on forever about support groups on the Net. Whether you’re
short or extra tall, anorexic or 300 pounds, a victim of cancer or of
child abuse, the Internet teems with people wanting to share their
experiences with you—a task made much easier through the efficiencies of
the Net, which have brought the cost of electronic mail down so much. I
bristle when I hear people talk about the Internet as worthless unless
big profits await megaconglomerates. The activities of support groups
and other virtual communities may not show up in any country’s gross
domestic product, but in the aggregate they’re just as valuable as
anything to emerge from AT&T or Time Warner.

May I emphasize that the Net is far, far more than a mental health
clinic? It’s a place, too, for political activists, boaters, golfers,
motorcyclists, gun owners, gourmets, football fans, baseball
enthusiasts, parents and teachers, writers and readers of many genres,
pilots, airline passengers, amateur radio operators, and reggae lovers.
All have their own niches, which is just what you’d expect with more
than 12,000 newsgroups.

While the clueless are arguing over whether the Net has value, people
like John Schwartz already know it does. Recently he wondered about
lyrics by a singer and songwriter named Liz Phair. Just how did they go?
Some of the biggest fun came from his hunt online. He tracked down at
least five different Web areas—“digital fan magazines”—devoted to Phair.
“Some had photos, some had biographical information, and a couple had
song lyrics.” And yes, he found the lyrics he wanted, and in their full,
unprintable glory. “Useless? Probably. Satisfying? You bet.” And
Schwartz went on: “Think of all the stuff that you’d find in your public
library if you pulled something off the shelf. A lot of it would be
‘useless’ for your own needs—tons of mediocre fiction, outdated
information, and silly things. But would anybody say that it proves that
libraries are worthless?”[1.6]

Other Net activities also suggest that _Snake Oil_ is self-descriptive.
A Michigan couple has started a virtual toy store complete with pictures
of their staffers as children and service of the kind you’d expect from
L. L. Bean; their first order came from Brazil (see chapter 2: Business
on the Net: From White Rabbit Toys to “Intel Inside”). Out in California
two young techies are giving hundreds of young musicians a break through
a much-needed project called the Internet Underground Music Archives
(chapter 3: EntertaiNet: A Few Musings on Net.Rock, Leonardo da Vinci
and Bill Gates, Bianca’s Smut Shack, and David Letterman in Cyberspace).
Just throw $100 their way and, for a year, you can post a sample of your
music on the Net and perhaps stir up sales of old cassettes and CDs.

At the same time that Stoll grouses that the Internet is unedited,
scores of dailies and weeklies are on the Net to one extent or another
(chapter 4: Pulped Wood versus Electrons: Can the Print World Learn to
Love the Net?). So’s _Time_ magazine. Random House, Macmillan, and Time
Warner are there, too, posting samples from various books, and soon
people at home will be able to send credit card numbers securely over
the Net and dial up the complete texts of bestsellers and other books.
Even now you just might be reading _NetWorld!_ off a screen rather than
from pulped wood.

Meanwhile, a digitized cadaver on the Internet may help revolutionize
the study of anatomy (chapter 5: Wired Knowledge: When They Let a
Murderer Loose on the Internet), and in Canada, leather-jacketed
teenagers are using the Net to develop their reading and writing skills.

A Mini Jargon Guide

• Electronic Mail or e-mail. You can use the Net and other networks to
  send messages to your friends in Peoria or Melbourne—anywhere, in
  fact, where Internet connections go, from Alaska to the South Pole. An
  electronic mailbox is just like the physical equivalent. It’s a little
  storage area where your messages pile up for you to retrieve when you
  want.

• File Transfer Protocol, or FTP. It’s a means to send or receive files
  from one computer to another.

• Gopher. This program lets you track down information on the Net. The
  word _Gopher_ also alludes to certain Gopher-style collections of
  computer files. Different Gophers connect to each other through items
  on menus. You might start looking at an article on water pollution
  from a computer in Washington, D.C., see a mention of an African
  river, click on that menu choice with your mouse or otherwise select
  it, and end up at a computer in Johannesburg.

• Internet Relay Chat. It’s like a huge party line except that people
  are typing rather than talking. You can open up private areas, too,
  and reach just one person.

• Mailing Lists. To be a bit simplistic, they’re just like regular
  electronic mail, except that a number of people share messages, to
  which you can typically respond privately or with the entire list.
  Some lists, however, let only the _moderator_ send out messages. Via
  Usenet, some mailing lists appear as newsgroups.

• Newsgroups. These are the bulletin board systems of the Net, in
  effect. Almost anyone can post messages there and potentially reach
  hundreds of thousands of people—far more than on most mailing lists,
  since people can read newsgroups without subscribing. The newsgroups
  are part of a service called Usenet, which reaches BBSs around the
  world, not just the Internet. No one owns this anarchy, and I wouldn’t
  want it any other way.

• Telnet. Without leaving my regular keyboard I can operate a computer
  at Oxford University or the University of California by way of a
  procedure called Telnet. I’m remotely controlling the machines at the
  other end.

• The World Wide Web. It’s the area of the Net that not only lets you
  read text but also see pictures, hear sounds, and even take in short
  clips from movies. Like Gophers, sites on the World Wide Web connect
  with each other. A program that lets you navigate the Web is known as
  a browser. Among the more popular browsers are Mosaic, Netscape, and
  Lynx (the latter, alas, won’t let you instantly enjoy pictures).

Also, the Net, in the opinion of many, is mocking Orwell’s predictions
(chapter 6: Governments and the Net: Making Sure Orwell Was Wrong). Some
serious threats remain—such as the efforts of American bureaucrats to
make the Net more friendly to snoopy cops—but 1995 is a long way from
_1984_. What’s more, the Internet doesn’t offer just sex.

Love, too, can thrive. The persistent may indeed find wives and husbands
on the Net (chapter 7: The Electronic Matchmaker).

This all happens on my Internet—anyway the one I’ll describe here. Let
me offer an inevitable caveat, however: The Net is too vast for one
writer to cover everything. So I won’t bother with Internet Relay Chat,
where you instantly see the other people’s typing. As a temporary
habitué of these regions, J. C. Hertz started to regard the Internet as
“a Sartrean hell—too many people talking at one time.”[1.7] Yes! Net
chat brings Hemingwayesque accounts from witnesses to Japanese
earthquakes or Russian coups, and I’m happy it’s around for the
aficionados, especially net.lovers, who can retreat to their own private
channels; but I myself favor electronic mail and newsgroups, which I can
read on my own terms without parrying incessantly with dyspeptic
strangers half a planet removed. I promise, dear readers: I’ll inflict
nary a chat transcript on you.

Certain omissions, however, really pain me. Given more time, I’d have
loved to cover the growth of the community network movement. For free,
in many cities, you can open up an Internet account and tap into
electronic libraries all over the world or receive electronic mail. Best
of all, “communets” can bring communities together. The Net is one of
the big lures to get people online, but once there, they may be able to
fetch the schedule of their local public radio stations, find out about
local charities, and talk back electronically to officials of city
halls.

What’s fascinating is the resemblance between these local nets and the
Net at large. People on both would rather chat with other citizens than
swap e-mail with the politicians or other celebrities. And why not?
Communets are communities, just as the Net, serving so many interests,
is a _series_ of communities. Alas, Stoll does not appreciate the
possibilities here.

Stoll is an astronomer, not just a hacker, and his makes me feel as if
he is using a scratchy pair of binoculars to look for life
on Mars. Fixated on negatives, he has downplayed even the
obvious: the Net equivalent of Martian mountains. Has Stoll
dropped by alt.music.chapel-hill, or rec.arts.dance, or
alt.christnet.christianlife, or the Dallas Virtual Jewish Community
Center Home Page, or the American Ireland Fund, or the Voter Education
Project? And how about the thousands of other Web pages in which
individual Netfolks can share with the world their love of families and
pets, or gardening, or , or old Chevies, or whatever else they enjoy, at
or away from their computers? Item by item, those are tiny, almost
invisible slices of Netlife; but en masse, they rise up as mountains.

Yes, yes, sex _areas_ thrive on the Internet. But it is that way
offline, too; do snack-food stores turn millions each year off Chaucer
or _Playboy_? Of course Chaucer himself could be randy at times, as
could Shakespeare and Joyce and hundreds of other literary greats—an
inconvenient fact for the American ayatollahs who hope to censor the
Net.

The biggest irony here is that the Internet can actually promote Family
Values and strengthen real neighborhoods. As George Gilder and others
have noted, the new technology can serve people’s exact needs rather
than just dish out the standard sex and violence so beloved to TV
networks. The Net is Example One in my opinion—especially The Barcroft
School and Civic League page on the World Wide Web. Several thousand
people live in the Barcroft area of Arlington, Virginia, near
Washington, D.C. It’s neither a slum nor a glitzy, status-crazed
neighborhood, just a good place to raise the families that the
ayatollahs love to extol. An old Methodist church has served as a
community house. Now an electronic equivalent is on the Web, complete
with a color photo of the church building; people can catch up with
neighborhood news and learn of ice cream socials.

I’m writing this paragraph just before the Barcroft Fourth of July
parade. The word from the World Wide Web is that Susan O’Hara
Christopher will be the Grand Marshall. People can enjoy Nancy
Tankersley’s watercolors of past parades, or “Jim Lande’s famous tree
trunk sculpture. Games for the kids, no political campaigning, hot dogs
and lemonade, the new Barcroft tee shirts and lots more!” The higher the
percentage of Netfolks among the citizenry, the more Fourth of July
bulletins we’ll see in cyberspace.

Across the Potomac in D.C., the Internet is helping to reduce the number
of hookers and drug pushers plying the Blagden Alley neighborhood. If
the police catch you looking for women or dope, a man named Paul Warren
will put your name on the World Wide Web. Thanks to his “Crimenet,”
residents no longer stand as much a chance of finding a hooker at work
on the sidewalk a few yards from toddlers in living rooms. Not everyone
would approve of the privacy implications here, but I myself love what
Warren is doing. Like thousands of small-town newspapers that print the
names of the arrested, Warren is just spreading around the public
record. A notice reminds readers that “Criminal defendants are presumed
innocent until proven guilty”; and he is willing to post an update for
anyone exonerated. Warren isn’t saying that prostitution should be
illegal everywhere, just that it should not force young families out of
Blagden Alley.

That, in fact, is how I feel about net.sex. If a fifth grader
encountered alt.sex.bestiality whenever he or she flicked on a computer,
why, yes, I’d join the ayatollahs. But the Net is not like the pre-Web
Blagden Alley or daytime television. You normally don’t find sex on the
Net—at least not the truly kinky type—unless you seek it out. And the
computer industry is working on software to reduce the chances of
children accidentally running across alt.sex.bestiality. Even now, of
course, the language in the average area of the Net is much cleaner than
the words in the locker room of the typical high school. Trying to ban
“smut” from the Internet would be like shutting down high school
football because _some_ sixteen-year-old tackles love to cuss at
teammates and gawk at nude pictures.

Granted, the Net has problems, and rather serious ones. A Californian
stole 20,000 credit card numbers from Net users; in New York some young
men met through the Net and figured out ways to order tens of thousands
of dollars in merchandise illegally. Many Netfolks think it’s too risky
to send credit card numbers over the Net itself when ordering
merchandise; better to use the telephone or fax. What’s more, just as
Stoll says, business on the Net is overhyped. Meanwhile the Feds have
reduced subsidies to the Net. Over in Australia there are already
bothersome charges for use according to the amount of material
transmitted, and people fear that the same could happen in the States.

Just as frustratingly, the technology isn’t quite there yet. Pictures
can take centuries to appear on my screen when I fetch material on the
World Wide Web. I hook into the Internet by dialing up ClarkNet, a
company in a barn south of Baltimore. This is one of the _best_
services, but a good part of the time, in recent months, I’ve suffered a
busy signal or worse when I try to dial in. Given the overcrowding of
the Net, electronic mail takes longer to arrive than it once did. I
believe Stoll when he says that in some cases the United States Postal
Service will get mail from one place to the other faster than the Net
will handle e-mail. That’s the exception, but I’m disturbed to see it
happen even part of the time.

I lament, too, the lack of commercial books available on the Net for
free, in the public library tradition. Cliff Stoll is absolutely right
to want better content, and my friend Jim Besser would agree with us.
Jim is a journalist avid for new facts; he regrets that so much of the
information on the Net is wrong or out of date. Beyond that, his
Internet connection sometimes goes south when he is under a deadline.

Cures for the Internet’s problems, however, are or could be on the way.
Technology will make the Net safer to use and more reliable—lo and
behold, the computers in the barn have behaved somewhat better these
past few weeks. Over the long run, too, Netlife will improve. Popular
programs in some cases, even now, are letting customers send credit card
numbers online without the hackers intercepting them. Net businesses
will take off when more people sign on and young hackers get jobs and
families.

The Internet will even survive the reduction of subsidies from
Washington. The price of the technology will just keep going down if
past trends apply, and if the government doesn’t let phone companies
gouge people. Everything is faster and cheaper. Once the experts doubted
that ordinary phone lines could carry signals at 9.6 kilobits, or 9,600
bits, per second. Today, even if I’m not IBM or the phone company, I can
cruise along at around 28.8 kilobits per second, which is enough to
receive a book in a few minutes.

If Cliff Stoll really wants electronic books, then computer networks can
transmit them. When, just when, will Washington be brave enough to work
toward a well-stocked national digital library offering commercial books
for all; why should we replicate online the “savage inequalities” of our
libraries and schools?

Netfolks aren’t the reason why such a library for the Internet is so far
off right now, and why we may well end up with a national digital
bookstore as opposed to a true library offering books at no charge or at
minimal cost. Even technophobic librarians—they exist, even if not in
the same numbers as before—aren’t the true villains here. _Lobbyists_
are at fault. Bill Clinton’s intellectual property czar, Bruce Lehman,
is himself a former lawyer-lobbyist who acts as if he is still fighting
for his old copyright clients. Members of his former law firm have
donated tens of thousands of dollars to influential politicians. And in
a five-year period people with corporate or family ties to a legal
publisher, West Publishing in Minnesota, have given more than $738,000
in political contributions, some of which went to members of Congress
influential on copyright matters.

With less eagerness to please lobbyists pushing for corporate business
plans—rather than for the commonweal—the U.S. government could divert
resources from bureaucracy to knowledge and pay publishers and writers
fairly. How? Suppose Washington would link the national library with a
focused program to buy hardware that schools and local libraries could
lend out. In effect the Feds would prime the private market by
encouraging mass production and by sending a message about priorities.
Small, tablet-shaped computers with extra-sharp screens could eventually
go on sale—much sooner than otherwise—for $99.95 at Kmart. And these
same machines, although designed for reading electronic books, would be
excellent for the Net or for filling out easy electronic forms; we could
save tens of billions in money and time in the private and public
sectors of America’s $6-trillion economy. Needless to say, too, this
affordable hardware could mean more eyes for retail businesses on the
Internet.

Then high tech wouldn’t pose such a problem to nontechie consumers and
to computerphobic women and minorities. A study out of the Georgia
Institute of Technology showed that 94 percent of the surveyed users on
the Web were male and 87 percent were white. With less-threatening
hardware and proper training of the right people, however, schools and
neighborhood libraries could help bring a much wider segment of society
on the Net. Cliff Stoll is aware of the possibilities here. He knew two
years ago of my TeleRead proposal to improve the content of the Net, get
many more people online, and spread the electronic books around from the
very start. How much easier it must be for him to eulogize old wooden
card catalogues and avoid a nasty tangle with lobbyist-cowed politicians
and bureaucrats.

               =Touring _NetWorld!_ Yourself—Via the Web=

Webfolk, check out the Internet Underground Music Archive, White Rabbit
Toys, electronic magazines, and many of the other Net delights I’ve
described in this book. Just use your Netscape, Mosaic, or other browser
to go to

http://www.webcom.com/~prima/networld.html

You’ll find there a list of various Web sites mentioned here in the
pulped wood _NetWorld!_—and perhaps some informal updates. You can reach
the sites immediately. Just click on the hypertext links. People at the
other end may change the links, but I’ve made them as up-to-date as I
could.

If you would like Net addresses of _some_ of the people mentioned in
this book, go to

http://www.clark.net/rothman/pub/networld.html

Perhaps you’ll also want to see a detailed electronic version of my
TeleRead proposal for a well-stocked, cost-justified national digital
library. It could let ordinary readers dial up the _entire_ texts of
copyrighted books from home for free without cheating publishers and
writers. For more on TeleRead, check out the hyperlinked Net incarnation
of my chapter in a forthcoming book _Scholarly Publishing: The
Electronic Frontier_ (Cambridge, Massachusetts, M.I.T. Press, 1995):

http://www.clark.net/rothman/pub/telhome.html

Bashing technology, of course, is hardly new. In 1854 a writer
complained: “We are in great haste to construct a magnetic telegraph
from Maine to Texas; but Maine and Texas, it may be, have nothing
important to communicate.” He said that “We are eager to tunnel under
the Atlantic and bring the Old World some weeks nearer to the New; but
perchance the first news that will leak through to the broad, flapping
American ear will be that Princess Adelaide has the whooping
cough.”[1.8] Henry David Thoreau was the writer and the words appeared
in _Walden_.

Does their source, however, make them less dubious? Hardly. Imagine
America without the telegraph—without an opportunity to forge lucrative
commercial ties with the Old World, or to strengthen Texas’s ties to
Washington. As it turned out, Texas and the rest of the country had
plenty to say. So did railroad employees talking to each other;
companies could more easily use single tracks to handle traffic in both
directions, knowing that the telegraph was there to handle
scheduling.[1.9] In other fields, such as medicine, the telegraph
undoubtedly hastened progress as well. It also helped friends and
families keep in touch as the country was settled; today the Net does
the same with people in this era of international travel. Technology,
then, while ripe with opportunities for abuse, can do far more than
recruit “Girls of the Net” or spread word of a princess’s whooping
cough.

Ironically, if the Cliff Stolls prevail, and if too many white hats
abandon the nets as “devoid of warmth and human kindness,” then his
predictions _will_ come to pass; the greedy will take over, confident
that others won’t mind so much.

Together with millions of other Netfolks, I’ll remember the Great
Spamming of ’94. Laurence A. Canter and Martha S. Siegel,
husband-and-wife partners in an Arizona law firm called Canter and
Siegel, wanted to sell their services as immigration experts. So they
splattered a “Green Card” ad—as if hurling spam against a wall—across
some 6,000 newsgroups on Usenet. They didn’t care if you preferred to
read about baseball or UNIX; they wanted your eyeballs. The Net seethed.
I myself disliked many of the tactics used against Canter and Siegel—was
it really necessary to threaten death or favor them with a slew of
unsought magazine subscriptions?—but clearly they merited some good,
strong, healthy loathing. I complained to the American Bar Association,
which, at the time, was spending hundreds of thousands of dollars on a
PR campaign to upgrade the image of lawyers. You might say that C & S
set the goodwill account back by several million.

My big regret is that I lacked more time to raise hell against Canter
and his wife online and in other ways. The glory of the Net, this
_series_ of communities, was and is diversity; here C & S were dumbing
it down to the broadcast model where one program served all. But Canter
and Siegel didn’t give a whit about the Net as it existed, about the
outrage that so many unwilling people were bearing the costs of sending
and storing their unwanted messages, about the fact that Usenet couldn’t
survive continued assaults in this vein, about the damage they were
doing to the various forms of Net culture, a phrase that C & S would
undoubtedly have dismissed as an oxymoron.

Canter and Siegel later added to the insult with _How to Make a Fortune
on the Information Superhighway_, the 1990s equivalent of a guide to
exterminating buffalo.[1.10] The book talked of selling to 30 million
people, which was malarkey. Some Net demographers challenged the figure
at the time—reality may finally have caught up—but more important, most
of those 30 million could only send and receive electronic mail as
opposed to using services such as the World Wide Web. And just how many
people wanted to receive junk mail from marketers? Of course C & S might
suggest mailing lists for the receptive—nothing wrong there—but without
access to the right Net services, fewer people would know of the lists
in the first place.

Does this mean that the Internet should be free of commerce? Quite the
opposite. The challenge is simply to avoid letting the hardsellers
overwhelm the Internet. Countless areas of the Net exist where people
not only tolerate ads, they _want_ to read them. Besides, the commercial
and noncommercial can build on each other. When I put my TeleRead
proposal on the World Wide Web—that is, my call for a well-stocked
national digital library with copyrighted books included—I built in
hypertext links[1.11] to Web sites that could be useful. And several
just happened to be commercial. The Minneapolis _Star Tribune_, for
example, had done a Pulitzer-quality expose of the thousands of dollars
that West Publishing had doled out in trips for some Supreme Court
justices who passed judgment on copyright matters. Just why should I
have avoided this superb material when a commercial publication was good
enough to share it with the Net for free?

Electronic cafes, found in San Francisco, Seattle, London, and Hong
Kong, among other locations, are another good example of how the
commercial and noncommercial can strengthen each other. Cafes with
Internet hookups can even help bridge the gap between Net and life. The
Internet Cafe at 1363 4th Avenue in Prince George, British Columbia,
doesn’t just offer a coffee bar. Customers of the local Internet
provider can pick up their e-mail there and wander around the Net, read
“a good, old-fashioned cork bulletin board for community information
exchanges,” learn about local service agencies, watch resident artists
at work, buy crafts from all over the world, and even get advice from a
local psychologist, Russ Winterbotham, who just happens to own the
place.

When Stoll writes about an Ontario bookstore with a water garden and
three cats, it’s easy to appreciate the potential charms of commerce
offline. But clearly the Net itself can spice up a traditional business.
In London, you can drop by the Cyberia cafe at 39 Whitfield Street and
plunk down £1.50 for a large cappuccino and £2.50 for a half-hour on the
Net. The word is that the cafe has drawn “more media coverage than a
small war.” I’m not surprised. Even if prices might be a bit lower by my
standards, Cyberia is meeting a definite need. Of course Stoll would
complain that the customers in the electronic cafes are “surrounded by
people, yet escaping into conversations with distant strangers.” Isn’t
he forgetting something, however: The way many Net aficionados love to
meet the like-minded in person?

I’m also keen, needless to say, on the pioneering work that thousands of
small businesses are doing on the World Wide Web itself—rather than
posting in-your-face ads to nonrelevant newsgroups.

No, Web businesses aren’t charities or consumer service organizations.
But by offering details about their products and services, they are
respecting our intelligence far more than does the huckstery on
television. You wouldn’t want to buy a new Buick or Volvo if you simply
went by statistics and photos on the Web. But you just might learn more
about gas mileage and safety claims than if you relied simply on the
sales rep and brochures in the showroom. The more you shop this way, the
more you’ll encourage manufacturers to improve their products and
services rather than just to shell out megabucks on more Super Bowl ads.
Net business, major limitations notwithstanding, is indeed A Good Thing.

Our first stop in _NetWorld!_, in fact, might well be one of my favorite
stores in cyberspace—White Rabbit Toys.




                                CHAPTER
                                  TWO

    Business on the Net:
    From White Rabbit
    Toys to “Intel Inside”


Bob Lilienfeld worked for Procter & Gamble and the outfit behind the
Muppets, and JoAnn Lilienfeld was a buyer at Bloomingdale’s. Nowadays he
consults on solid waste and other environmental issues. His wife, a
neatly coifed woman who looks and dresses like an upscale
schoolteacher,[2.1] has started a toy store called White Rabbit Toys in
honor of the character in _Alice’s Adventures in Wonderland_. Bob enjoys
technology. JoAnn herself is no slouch in that area. They are in their
forties now but relish new marketing wrinkles just as much as when they
were earning their MBAs from Northwestern University.

So Bob and JoAnn Lilienfeld have set up shop on the Internet, where, in
a surprising but logical way that a mathematician like Lewis Carroll
would have loved, their respective business ventures mesh.

Wandering through commercial listings on the Web, I discovered the
virtual White Rabbit just as Christmas shoppers were crowding the
corporeal White Rabbit up in Ann Arbor, Michigan. Bob was a
technohusband par excellence. He designed the toy store online, claimed
just the right address on the World Wide Web (http://www.toystore.com),
wrestled with the technical issues, and helped take orders from
customers, the first of whom lived in Brazil. JoAnn would pay Bob in his
favorite currency: teddy bears. The big question was: Will they make any
money at it? I electronically hung around their virtual store and
chatted with Bob on the phone as the season progressed.

He and his wife were among the thousands of small business people who
were trying new marketing paradigms on the Net, where the denizens hated
intrusive huckstery but might take to electronic catalogues.

Compared to most other business people on the Internet, the Lilienfelds
were quick studies. You could type an electronic address into your
computer and see a White Rabbit logo and a greeting from the toy store
in several languages. Then you clicked your mouse on the proper area of
your screen and opened up a colorful catalogue with not only blurbs but
also pictures of tops and puzzles and wooden toy trains of the kind your
parents might have bought for you. Most of White Rabbit’s offerings were
classics that you would never see at Toys ᴙ Us.

Bob and JoAnn Lilienfeld wanted their business to stand out. Soon their
electronic forms might let you type in the age of your child,
information about his or her interests, your budget, and other
constraints. You would instantly receive tips on what gifts to buy. Even
now, you could order online without talking to a human—not as heartless
as it might sound, if you simply valued your time and telephone money.
The electronic forms could even calculate the postage.

White Rabbit intrigued me, and others felt the same way. Within a few
weeks of my first visit, they got calls from the _Wall Street Journal_
and the _Detroit Free Press_. Some reporters had caught on to the
obvious: While Hollywood and Washington were off prattling clichés about
the overpriced medium called interactive TV—while Al Gore was cracking
jokes on stage with Lily Tomlin during an entertainment summit disguised
as an “information” one—entrepreneurs and Fortune 500 companies were
trying ads on the Net. The Internet often narrows differences between
large and small businesses. Even little ones can reach global audiences
and, through well-planned Web areas, look like giants to customers in
Rio or Tokyo. New cybermalls sprout up to get technophobic companies
online by providing both technical and creative services. Corporations
fight over addresses for the Net. Stanley Kaplan, a service that tutors
students for academic examinations such as the Scholastic Aptitude Test,
sued a competitor that stole the name kaplan.com. A writer for _Wired_
magazine mischievously claimed McDonald’s name, which the hamburger
chain hadn’t yet registered. Such oversights, however, were rapidly
becoming the exception in an era when prime Web sites made the pages of
_Newsweek_.

Even electronic hookers (“We go all the way”) were on the Internet—in
fact, operating under the name “Brandy’s Babes.” They plied their trade
from Arizona, the same wild and quirky state from which Canter and
Siegel enraged the Net. And yet, if you cast the usual moral questions
aside, the Babes seemed to be exemplary citizens of cyberspace. Not just
hypesters, they posted specifics like prices, bust, hip, and waist
measurements, and preferences in men. “No beards,” a Babe warned
customers. “Employed men only.”

Unlike the hardsellers, the Babes did not inflict unwanted ads on
thousands of newsgroups. And in line with the two-way traditions of the
Net, they solicited messages from customers—dirty ones that the Babes
might charge good money to answer. You could even dial up Brandy’s and
see a live Babe at her computer with her impressive bosom exposed. The
gig lasted several zany months. Fear of police raids grew, however, even
before the ayatollahs in the U.S. Senate ranted against net.sex. I
finally saw just a blank screen except for a laconic message alluding to
“bad links.”

Separately a condom store was online as well. It offered medical
information, supplied tantalizing odds and ends on such topics as “The
Size of a Man’s Pony,” and wittily answered questions from appreciative
readers. Like Brandy’s, it operated in a nonintrusive way.

The World Wide Web was also a virtual home for thousands of more
conventional businesses such as the manufacturer of a toy gun that shot
Ping-Pong balls, a city’s worth of bookstores, Godiva chocolate, and
Ragu spaghetti. None other than the Home Shopping Network bought out a
Net retailer specializing in computer equipment. Pizza Hut went online.
And the United States was hardly alone in this trend. The Singaporeans
were competing in the cyberpizza race—Shakey’s Pizza was girding to take
orders, via a fax-Net link, from hungry scientists and students at the
National University of Singapore. A large Irish bank advertised on the
Net. So did the Royal Bank of Canada. It mounted a bilingual Web area
for both English- and French-speaking customers who, once past the first
menu, didn’t have to clutter their screens with material in the wrong
language.

Some of the old technical barriers, of course, remained even in rich
countries: most hardware was still rotten for doing home shopping. What
the customers needed, and what Silicon Valley could not yet provide,
happened to be small, affordable, sharp-screened computers that could
colorfully show off the merchandise. The main way to look at the Net was
through Mosaic-style programs. And even at 28.8 kilobits per second—the
highest speed possible through widely available modems—it took too long
to go from page to page of electronic catalogues. The biggest problem
was the software installation, which could be tricky. Although software
such as Internet in a Box simplified the matters, the Net was not yet
TV-easy to use.

Even so, some companies were designing inexpensive gadgets, which could
sell for mere hundreds of dollars, that would allow people to surf the
Internet on their televisions. I hated the idea of anyone reading text
off a blurry television screen. But at least the powers of the computer
world were finally thinking of the Internet as a real, live marketplace.
Just as important, Prodigy, America Online, CompuServe, and rivals were
preparing to let customers reach Web sites from their proprietary
networks.

Microsoft was planning point-and-click Internet capabilities for its
Windows 95 operating system. And it had bought stock in a key Internet
provider and would be linking its own network tightly with the Net.
_Advertising Age_ estimated the number of people able to access the Web
itself—the best place for Net advertising—at several million at the
start of 1995.[2.2] And that number might push past 11 million by 1998,
according to a report from a Massachusetts research firm.[2.3] So, even
if Internet merchants aren’t advertising in the most consumer-oriented
of places right now, they might well be awash in new business later on.

The existing denizens of the Internet were more technical than the
people on, say, Prodigy or America Online. Some software companies used
this to their great advantage. A good example was Cyberspace Development
Company, which had created an extraordinarily useful program called The
Internet Adapter, or TIA. Most Net people couldn’t enjoy Mosaic-style
viewers because their network connections did not allow this. But TIA
let even Netfolks with $18-a-month accounts use Mosaic and other
marvels. And to buy TIA, they did not have to go to a retail store.

If technically savvy, they could pick it up on the Internet itself. A
digital key, transmitted via e-mail, allowed only authorized customers
to use the publicly available files. Skeptics could try a test version
of TIA for a few weeks before paying for it by check or credit card.
Because of the low cost of distribution and, in my case, the lack of
need for full consulting services, I spent just $25 on a product that
might have cost a good $50-$75 if sold at the usual store. And by
normally using a basic hookup with my Web software—as opposed to a
deluxe, time-sensitive one—I could save hundreds of dollars a year.

The benefits of the Internet, for the Cyberspace Development Company and
me, didn’t stop there. Via discussion groups, TIA sellers kept us
customers up to date, and just as important, we could share tips among
ourselves. We could also use the World Wide Web to catch up with long
documents; in fact, updated versions of TIA could travel to us over the
Net. All of this, including the elimination of the need to go to the
store, was taking place on commercial networks such as CompuServe. But
the costs would have been greater for Cyberspace and customers alike if
the company had to pay the usual commercial rates for electronic mail.

Among the wares talked up online were upbeat prognostications about the
Net itself. For $3,500 you could buy a report from a California
consulting firm that said annual commerce on the Net and commercials
services such as CompuServe would reach $600 billion by the turn of the
century. I was skeptical. Merchants like JoAnn Lilienfeld would have to
sell warehouse after warehouse of stuffed animals or toys or whatever
the offerings were. In fact, $600 billion was a good 8 percent of
international commerce. On reflection, however, the estimate from Killen
& Associates seemed possible. Through the Net you might find a buyer for
shipload of scrap iron or an office building, not just a stray teddy
bear in need of a child. I phoned Mary Cronin of Boston College, who had
written a well-regarded book called _Doing Business on the Internet_. It
teemed with examples from Digital Equipment Corporation and IBM and many
other computer-oriented firms. And she had researched it before most
business people grasped the importance of the Internet. Yes, she said,
the $600 billion figure sounded credible if you counted
business-to-business transactions.

Daniel Dern, an Internet consultant, had his own opinion on the
statistics. He said the Net was like the highway. Just what did you
count—all the goods that went over the road? The combined salaries of
the people on the way to work? I could see his point.

Whatever the exact numbers, the demographics and technology might be on
the side of the many retail businesses if they stuck it out on the Net
and kept expectations realistic. Scads of people in Generation Net were
about to marry. They would buy houses and cars and whatever else
mattered beyond stereos and Internet-optimized computers. Just in the
late summer and fall of 1994, the number of Net-related businesses on
the Web had doubled, and a good many of the newcomers were not
technical. Could the Net really, then, enrich business people without
technical backgrounds? Was there indeed money in what had once been the
province of cash-strapped college students and dreamy researchers?

Plenty of people thought that the answer lay in the case history of
Grant’s Flowers, which, like White Rabbit Toys, operated out of Ann
Arbor, Michigan. Larry Grant had been a cover boy in an enticing article
on the front page of the business section of the _New York Times_; the
Internet pulsed with chatter about the electronic coups that he
supposedly had achieved for just $28 a month. Excited Netfolks reported
that he did not even have to type to his customers on the Internet; new
orders just poured in on a fax machine with a Net connection. The
California gold rush was almost a century and a half old. And yet,
watching the Grant legend take off, I might as well have been among the
boots and beards at Sutter’s Mill.

So I talked not only to the Lilienfelds but to Larry Grant, the
legendary florist himself. Many in the media were still enchanted with
the Electronic Frontier metaphor, and I remembered the old films about
Davy Crockett, the Tennessee frontiersman who loved corny jokes,
bear-wrestling tales, coonskin hats, and Crockett-friendly news
accounts—the grist for Walt Disney later on. What was next, a movie epic
with a musical tribute to “Larry Grant, king of the Net frontier”?

A market might indeed be ballooning for cyber-retailers, as the
hypesters said. But I still wondered about the present. What counted was
not all the puffery about 30 million Netfolks, many of whom can only
read electronic mail as opposed to _seeing_ roses or toy tops or other
merchandise. No, the real determinant was how often people dial up your
particular site and bought. One well-crafted Web area, which advertised
technically related goods, enjoyed just a handful of visits in six
months without a single sale. This was an issue aside from the total
amount of business done on the Net. Having talked with Mary Cronin and
others, I hadn’t any doubt about those giant commodity transactions and
all the use of the Net by Big Business to automate the paperwork of
commerce. But what about the small fry? Was the excitement about Grant
truly justified? I’ll answer those questions in the pages ahead, where
I’ll return to the Lilienfelds and to Grant, and where I’ll examine the
following:

• MCI, the phone company. It has provided thousands of miles of Net
  connections and now rents out electronic storefronts on the Net. MCI
  offers one of the slickest Web areas—complete with a fictitious
  publishing house (now evolving into a real one) that accepts
  manuscripts from real readers. _Advertising Age_ has hailed the MCI
  site as “unquestionably the best Internet marketing effort to date.”
  Frustratingly, however, while preparing to dispense advice on
  cyberspace, MCI in early 1995 was committing some of the very mistakes
  it should be telling its customers to avoid.

• Federal Express, whose Internet presence shows the potential of the
  Net for business-to-business transactions, not just the consumer
  variety. Ironically the people at FedEx in some ways were
  demonstrating more Net savvy than MCI was at the time, even though the
  Internet was more in the territory of the latter. The old values of
  customer service still reigned above all else. A smaller competitor of
  Federal Express, a shipper called Right-O-Way, was also making
  outstanding use of the Net. In some ways it was even staying ahead of
  the big boys.

• Intel, the chipmaker, which learned the hard way how good the Internet
  was for spreading news of flaws in products. The Net abounds with
  skeptical academics and consumerists with _fast_ typing fingers.

• Other hazards of the Internet for business people. What if you set up
  an electronic storefront like the Lilienfelds’ and then a manufacturer
  decided to cut out the middle people and sell on the Net directly or
  through a larger outlet? Security is another threat. While I was
  writing _NetWorld!_, most commercial areas on the Net lacked a way to
  protect credit card numbers. Hackers broke into General Electric’s Web
  area and stole corporate secrets. Another risk is competitors looking
  over price lists and assessing the strengths and weaknesses of
  products.

Those caveats will end the chapter. By far, the Internet is a positive
rather than a negative factor for business and customers alike. Wired
consumers will reward good companies, punish the losers, and spur the
winners to do still better.

Bob and JoAnn Lilienfeld: The Net as a
Way to Promote Small Businesses

Thousands of miles to the south of Ann Arbor, home of White Rabbit Toys,
Luciana Gores was reading a popular mailing list called Net Happenings.
It was a kind of town crier. Each day from North Dakota a man named
Gleason Sackman sent out informative posts on the many new services that
were springing up on the Internet.

Gores worked as a network expert, and she was already used to buying
technical books through the Internet, which offered a far greater
variety than what she would find in her own city, Rio de Janeiro,
Brazil.

She was also the mother of a seven-year-old named Lucas. So when the
mailing list told her of White Rabbit, she checked it out on the Web.

People who visited the virtual store, or at least those with the right
equipment, saw a logo with the rabbit from Lewis Caroll’s imagination.
They also conjured up a color picture of a real toy store with shelf
after shelf of tot pleasers, a tiny table and stool on the floor, and a
look of friendly chaos—in short, a shopper’s delight for children and
parents alike, which in fact the “real” White Rabbit was. The
traditional store, the one at 2611 Plymouth Road, had thrived. Now Bob
and JoAnn Lilienfeld were trying to woo virtual customers such as
Luciana Gores. Their electronic White Rabbit just may have been the
first full-service toy store—as opposed to one-product billboards or
specialty shops—to open up on the Internet.

An ad on the opening screen helped set the tone for Luciana Gores and
other customers of White Rabbit: “We specialize in high-quality toys
that help children to create, learn, imagine, and explore. Our toys come
from all over the world. We offer such international favorites as Brio
(Sweden), Ravensburger (Germany), Primetime Playthings and Creativity
for Kids (United States).”

Suitably equipped customers could actually see pictures of the toys,
including a Ravensburger game called the A-maze-ing Labyrinth. “Travel
the corridors of the enchanted labyrinth in search of treasures,” read
the carnival-like pitch. “But watch out! The walls shift, and the
passages can close, leaving you trapped! For ages eight and older.”
Lucas was a year younger, but did it matter if the child was as bright
as his mother, the network expert? “It seems to be an interesting game,”
Luciana Gores e-mailed me, “and it won a Parent’s Choice award.” And so
she paid her $24.95 and shipping, which, given the light weight of the
toy, was modest.

Thanks to the Internet, the Lilienfelds suddenly had the whole world as
a market, not just customers living near by. The fact that White Rabbit
was in a university town, with graduates all over the planet, could only
help. So could the fact that the Internet was expanding overseas even
more rapidly than in the United States.

White Rabbit also appealed to Stuart Lowry, another promising kind of
customer—the computer jock turned family man. A Maryland resident in his
late twenties, he wouldn’t have made the pulses of marketers quicken
several years ago; he was a grad student then at Johns Hopkins
University and, like many people on the Internet, had more time than
money. But that had changed. Lowry now worked at Computer Science
Corporation, a large defense contractor, pulling down a salary in the
mid-forties. He was married and lived in a townhouse, and four months
ago his wife had given birth to a baby boy. And so, when Lowry was
cruising the Internet from work and spotted a notice announcing White
Rabbit Toys, he favored it with a virtual visit. He ordered a colorful
toy top for $13, the Floor Spinner from Primetime Playthings.

Many people on the Web were young males more interested in pizza or
condoms than in baby toys, but the Lilienfelds were looking ahead a few
years when the same Net people would be parents. “It’s an act of faith,”
Bob Lilienfeld said. “Today’s demographics and selling a lot of toys on
the Net may be out of synch. But today’s college students are tomorrow’s
parents. Tomorrow’s parents aren’t going to consider ordering by
computer any different from getting in a car and going to the shopping
center.”

Other trends might work in the Lilienfelds’ favor. More and more
Americans were time-short, with long commutes; Stuart Lowry himself
spent forty-five minutes each way, and that actually was a quick trip
compared to those in cities such as Los Angeles. In northern Virginia I
knew of parents rising at 4 A.M. to go to jobs in Washington some forty
miles away, and not a few of them were high-tech workers who would
sooner or later end up on the Internet.

When I reached Bob and Jo Ann Lilienfeld in the middle of November,
White Rabbit itself had been on the Net maybe a week and had enjoyed
around 1,000 virtual visits in that time. They were hoping that these
numbers would multiply as Christmas neared. It was too soon to tell how
many of these people would actually order. Back in June, though, the
Lilienfelds had grown excited after reading about Larry Grant in the
_New York Times_ and elsewhere.

“I saw this figure of 20 million Net users,” Jo Ann said of the numbers
du jour, “and thought there’s definitely an opportunity here. But I
didn’t want to go about it in a half-baked manner. I thought there had
to be someone who could combine knowledge of the Net with marketing
experience.” She checked out a local cybermall and found it wanting in
the latter area.

That wasn’t surprising, given Jo Ann’s perfectionism and eagerness to
avoid easy but far-from-satisfactory solutions—whether in retail or life
in general. She had grown up in a cash-short household where, more often
than not, the children would get out the oatmeal cartons and
construction paper and scissors and cobble together their own toys. And
the same creativity had carried over to her Bloomies days as one of the
resident experts on Christmas tree trimmings. According to the
Lilienfelds, it was JoAnn who came up with the idea of selling leafless,
white branches. She and Bob had moved to Ann Arbor because he kept
flying off to the Midwest to consult for clients in Midland, and they
felt that married people needed to spend more time together. JoAnn went
about establishing the White Rabbit just as conscientiously.

Not finding the right toys for her own children, she studied the
demographics of Ann Arbor to verify that a toy store could thrive there.
She concluded that in a university community, many would love those
wooden train sets and other classic toys as opposed to the trendier
offerings that were touted on television and sold at Toys ᴙ Us. Ann
Arbor responded well. A local paper told how she blessed her store with
a public bathroom—how she kept diapers and spare wipes around for the
parents of children and emergencies. No need for toilets existed on the
Internet. But even at this early stage, having read up on the Netfolks,
she was attuned to the need to adapt to the culture of cyberspace.

JoAnn finally decided that her best savior, the requisite miracle-worker
with both Net and marketing experience, lived right there in the
Lilienfeld household. Those past few months her husband had been
succeeding off a mix of garbage and the Internet.

To be exact, Bob Lilienfeld was advising clients about _future_ garbage,
the packing materials for consumer products, a major contributor to
landfills. He hadn’t anything against recycling. But thanks to his work
at Procter & Gamble, he had concluded that the best way to cope with
waste was to design packages to avoid it in the first place.
Manufacturers and customers alike would win. Bob would go on to help put
together a network of likeminded consultants, including William Rathje,
a world-famous garbage expert at the University of Arizona who had
co-authored _Rubbish! The Archaeology of Garbage_. Lilienfeld met Rathje
at a press conference but also found himself relying on another source
of contacts, the Internet. Again and again he had heard about the Net
from professors at the University of Michigan, and he soon was in touch
with other garbage mavens around the planet.

“I started sucking in information,” he recalled. “I found out about
mailing lists and newsgroups, and then I decided I would put my
newsletter up on the Net and see what happened.” The newsletter was a
way to let clients know about his consulting company, the Cygnus Group.
It helped Fortune 500 companies, other businesses, trade associations,
educational groups, and others grow more sensitive to environmental
concerns in activities ranging from packaging to marketing.

Just as JoAnn was careful to befriend Ann Arbor in the right way, Bob
tried to honor the conventions of the Net—avoiding hucksterism in favor
of helpful information. The announcements about the newsletter were
low-key, and response was good. Soon he was sharing his articles with
hundreds of Netfolks who asked such questions as: “I recently saw an
article on compact fluorescent light bulbs in _Consumer Reports_. Why
aren’t more stores and utilities selling them?”

An “Ask Bill and Bob” column, cowritten with William Rathje, revealed
that such lights “take at least eight times more energy to produce than
old-fashioned bulbs. And they’re heavier, so they use more energy during
shipping.” The column also told of an experiment that McDonald’s was
conducting in Albany, New York, with food and paper composting, saving
perhaps 500-700 pounds per week of solid waste. Readers could learn,
too, that a nut seller was moving from glass and plastic bottles to
vacuum bags.

Bob Lilienfeld was hardly an eco-activist by the standards of, say,
Greenpeace; Dow Chemical was among his prime clients, after all. But he
was serving up information for people with many different viewpoints,
and by way of the proper clicks with your mouse, you could travel from
his Web site to areas of the Internet such as the Envirolink Network, or
EcoGopher, or EcoNet.

His newsletter, known as _The ULS Report_ (short for “use less stuff”),
carried an item about CD-ROM disks. It described them as “an
environmentally friendly way to reduce waste and save resources. One
CD-ROM, including packaging, weighs under half a pound. The 22 books
that it replaces weigh 70 pounds.” Knowingly or not, he was helping to
pave the way for the virtual White Rabbit—where the same principles
applied. Via the Internet, White Rabbit could advertise to thousands
without printing up catalogues for them. Oh, they might request
catalogues later, but then they would have prequalified themselves,
reducing the solid waste. Lewis Carroll would have approved of the
reasoning here. What’s more, unlike paper catalogues, Lilienfeld could
update his electronic catalogue to change prices or play up the
fastest-selling merchandise.

The World Wide Web was the main way to put White Rabbit on the Internet.
Once merchants on the Net would have favored a service called Gopher (as
in “go-fer-it”) in honor of the mascot at the University of Minnesota.
Gopher displayed text very well and needed less bandwidth on the Net
than the Web did. But it lacked the pizzazz of the Web-Mosaic
combination; that is, the ability to conjure up pictures and even sound
so easily. Although Bob used Gopher for digging up scholarly works about
the environment, it was like black-and-white television while Web-Mosaic
was color and all the more alluring for commercial purposes.

Getting White Rabbit on the Web was surprisingly cheap in some ways. The
Lilienfelds’ network provider charged JoAnn just $50 a month, plus $2 an
hour for when she was using electronic mail or handling other chores.
That didn’t include Bob’s time, however. He knew at least the basics of
the necessary programming language and didn’t require the services of a
consultant to the extent that others might have.

Net.business, 3D-Style

You can’t _touch_ merchandise on the World Wide Web. But the next best
thing may be in store.

Virtual reality will let you “walk” through Web businesses and see
merchandise in greater detail as you get “closer” to the object on your
screen. You can vary the angles, too. So you could use your mouse to
tour a parking lot of automobiles. You could spot the Volvo or the
Saturn of your dreams, and admire not only the outside but also the
interior.

No, the Web will never replace actual shopping in most cases, but
virtual reality will be increasingly good at helping you screen
preliminary choices.

Keep an eye out, then, for WebSpace—the new 3D viewer from Silicon
Graphics, the California company whose technology helped create many of
the special effects in _Jurassic Park_. WebSpace will work as an add-on
with popular Web browsers such as Netscape and Spyglass Enhanced Mosaic.

WebSpace-style technology, needless to say, is far too good to waste on
shopping alone. Virtual reality software for the Web may also help you
tour the National Gallery of Art, the Library of Congress, or Mount
Kilimanjaro—not to mention Hong Kong or Rio de Janeiro.

3D technology could revolutionize the financial world. Small investors,
not just high-powered stock analysts, could “see” stock market trends.
Your screen might display a “Bulls’ Corner” with a collection of
corporate logos color-coded according to the improvement in the stock
price. You could open up the logos and go on a tour of various
divisions, wandering around them electronically with far more ease than
you could with less advanced software.

Similarly, at the suggestion of your broker, you could tour a Bear’s
Corner and see why you might avoid or sell off certain shares.

Mind you, there are negatives. Corporations—whether stores selling
merchandise or companies seeking investors—may use this slick technology
to fool the public. On the other hand, the Internet is already a godsend
for consumers and small investors. Via Usenet newsgroups and mailing
lists, they can swap information, taking care of course to look for
plants from companies trying to sway grassroots impressions.

Lilienfeld himself put in most of the set-up hours. It took him a few
days of programming to design the Web site and scan in the pictures of
more than two dozen items—the train sets, the puzzles, the tops, the
blocks—and like an old-fashioned art director he had to create within
the limits of the medium. The big problem was photos. If they were too
big to move over the Net quickly, then the peeved readers might give up
and go on to another Web site. If too small, however, the pictures would
lack enough detail to show off the store or the merchandise. In many
cases Bob would let readers click on pictures of bears to see larger
versions of the photos.

He also had to worry about the software the readers used on the
Internet—certain Mosaic-style browsers would show _smaller_ objects
first. Other challenges arose. What if technical standards changed so
that only certain browsers would work with Bob’s site? The real White
Rabbit might be a victim of acts of God such as the ebb and flow of
automobile traffic, and the virtual Rabbit needed to worry about
patterns of Net traffic, but it also could be subject to Jehovah in the
form of macho software firms who wanted everyone on the Net to use their
brainchildren.

Companies such as Netscape Communications Corporation actually gave away
Mosaic-style products to us Netfolk for free, hoping to make fortunes
instead off the software that merchants and others denizens on the Web
would run. Netscape was the champ in late 1994, the one that let you go
from page to page faster than any competitor did. Many people feared
Netscape would be to the Web what Microsoft was to software; suppose
Netscape used technical prowess and marketing skill to trample
competitors, and maybe overcharge the customers.

A green monster named Mozilla came up on one of Netscape’s welcoming
screens, and pessimists wondered if the company itself might someday
play the part. Marc Andreessen, the top software designer at Netscape,
had led the team that came up with the original Mosaic at the University
of Illinois. And then he had left Illinois to join a new company that,
from the ground up, had designed the speedier Netscape product. The Web
community mightily hoped that Mozilla and keepers would behave
themselves. Suppose that Netscape joined Microsoft or credit card
companies to build in special, billing-related features that users of
other browsers couldn’t use?

Netscape, however, seemed benign so far, and the browser’s technical
wizardry was winning many friends. With a click of the mouse, for
example, you could scoot smoothly from the Web to the usual newsgroups,
and Bob Lilienfeld took advantage of this. He set up his computer system
so that customers with the proper software could whiz directly from
White Rabbit to child-related newsgroups.

One moment you could be shopping for toys; the next, exchanging tips
with a New Zealander or Norwegian on how to cope with tantrum-prone
babies. You could zip to misc.kids (“A great place to swap parenting war
stories”), misc.kids.consumers (“Help with purchasing decisions”), or
misc.kids.computer (“Enough said!”). Or you or your children could read
odds and ends about wombats, Forester kangaroos, Tasmanian devils, fish,
lions, dinosaurs, and other creatures at WombatNet; print out drawings
of the human heart or the stars or hear a thunderbolt by way of the
Franklin Institute Virtual Science Museum; and learn the population of
Uganda or Afghanistan via _The CIA World Factbook_, a guide assembled by
the real-life Central Intelligence Agency.

Fighting the companies such as AT&T and the big cable interests, many
activists likened the Internet to a series of communities with
opportunities for small merchants and citizen-to-citizen communications
as opposed to couch potato offerings from the Fortune 500. Merchants
such as the Lilienfelds were acting out the very models about which the
activists waxed so enthusiastically.

Bob Lilienfeld understood that just as storekeepers in a small town
would do well to join the Kiwanis Club, virtual storefronts should be
part of Net life. JoAnn would soon go to a toy convention, and at some
point, she might well share her impressions with the denizens of
misc.kids and similar newsgroups, as opposed simply to touting her
products. At the same time, yes, by way of a signature at the bottom of
her posts, people on the Net could find out about the toy store. She
might even start a mailing list for the receptive. Bob had already shown
the success of this model by way of the list and other tools used to
promote his consulting activities.

A toy-oriented list could be much more than ads. “Going shopping isn’t
just spending money,” Lilienfeld observed, “it’s a social phenomenon.
It’s seeing people you know, it’s being part of a crowd.” And it’s also
picking up gossip and maybe even solid information. “Ultimately the toy
store will be bigger than just a toy store,” he said. “We might be
providing information on child development, of the appropriateness of
certain toys or coloring books. If you’re a model train hobbyist, we
might be able to help you hook up with model train users groups.”

In fact, by way of the mouse-activated links from White Rabbit to
newsgroups and other Web sites, he was already offering much more than
just a store. The line between merchants and information providers was
blurring in the case of Bob and JoAnn; the higher the quality of the
information at White Rabbit, the more it would be a virtual gathering
place for people on the World Wide Web. I wasn’t surprised to hear some
people say that librarians might be the star sales reps of the future.
It wasn’t hype. Information, not just prices and selection of
merchandise, would be what drew Netfolks to sites such as the
Lilienfeldss’ . Of course Bob Lilienfeld might want to be choosy about
what links he listed. If he listed too many of the mediocre ones, then
he would simply be replicating the function of the powerful search
programs on the Web and adding to people’s “information overload,” to
use an ever-popular phrase.

Software already let sophisticated Netfolks zero in on items of
interest. Merely by typing in the word “toys,” for example, I could find
scads of listings—from mentions of adult sex toys to the Web site
advertising the gun that fired Ping-Pong balls. And these programs would
soon be simple enough for even technoklutzes to use. So the Lilienfelds
had better offer something that the software could not supply: Their
judgments about which Web sites, newsgroups, and mailing lists were the
most fun or most informative.

All through the Christmas season, JoAnn kept refining her Net-related
plans. “We need to ask, ‘Have we chosen the right items?’” she said.
“The draw of our toy store is, it’s an exciting place to shop. We have
to do the same on the Internet. If we add more items, it will approach a
catalogue more. Right now our competition is mail-order catalogues, and
we have a lot of items that they’re not offering. Maybe we’ll be
reaching people not on the traditional catalogue list. They could be
more occasional toy buyers than frequent toy buyers.”

Thanks to a computerized inventory system, JoAnn’s corporeal store
carried more than 6,500 items. Bob made a mental note: He might want to
put more of them on the Net so customers would enjoy a wider selection.
JoAnn talked about her suppliers: “My goal was really getting this up
and going for Christmas. When I get to the toy fair I’ll discuss this
with the national sales managers and see if I can’t get discounts for
advertising to so many people, and then we’re working probably toward
next Christmas. We’ll be working toward fourth quarter of ’95.”

That was a healthy attitude. Even toward the end of the season the
number of visits didn’t go past 2,000 a week, and only a handful of
actual sales resulted. The only customers were Luciana Gores; Stuart
Lowry, the computer jock turned family man; Michael Wolfe, a West
Virginia professor studying Internet commerce, who ordered half a dozen
stuffed toy caterpillars; a second academic, in the Midwest, who bought
a Ravensburger Snail’s Pace Race game; a Massachusetts woman sending
three customizable dolls to her sister (“I’m testing business on the
Net—aren’t you lucky?”); and David Fry, the operator of a cybermall
nearby who was curious about the White Rabbit, and who bought First
Blocks.

Not that the Lilienfelds had completely wasted their time. As of
Christmas, a _Wall Street Journal_ story hadn’t appeared, but the
Detroit paper and others had gone ahead with articles, and customers
poured onto the floor of the real White Rabbit, one even buying the
giant polar bear that Bob had been hoping to give his nine-year-old son.
The publicity may have brought in some $20,000-$25,000 in extra sales by
Bob’s estimates, on which the Lilienfelds may have netted around
$2,000—compared to $750 gross and $75 net from Net orders. Bob told me
that other merchants on the Web were also reporting a low number of
sales. The week before Christmas the number of visits to White Rabbit
itself actually declined; many of the prospective customers had been
logging on from school or work, and now they had partly emptied the Web
along with their dorm rooms and offices.

From a get-rich-quick perspective, then, the virtual White Rabbit had
been a zero. Bob and JoAnn were smart marketers with MBAs from a Big Ten
business school, and he had a real feel for the Internet, which he had
successfully used to expand his consulting business. But even the
Lilienfelds could not score right away. Oh, how tantalizing the
gargantuan numbers had been—the tens of millions of users said to exist;
the million by which the Net was supposed to be growing each month. And
yet in the end, when the time came for customers to key in the credit
card numbers, the market had vanished like the Cheshire cat. That didn’t
mean the Lilienfelds were foolish; just a week or two after Christmas, a
wonderful twist happened. The number of visits to the toy store fell
off. But sales leapt up. By mid-January White Rabbit was moving an
average of a toy a day—not a Kmart volume, but an improvement. Bob
explained the difference. Now White Rabbit’s first screen told customers
that the store could often get toys not mentioned online.

Encouraged, Lilienfeld added yet another improvement, an 800 number. Now
customers could ask their questions the old-fashioned way if they
preferred, and they could also order by voice if they didn’t trust the
Net with their credit card numbers.

With enough tweaks like this, the virtual toy store might eventually
flourish as the number of Web users grew. Just like the characters in
many children’s stories, the White Rabbit would keep on changing—adding
ever-more-intriguing links to newsgroups and other Web sites, putting in
the software to help novice toy shoppers choose just the right ball or
train set, figuring out new ways to use the interplay between the Net
and the traditional media. Sooner or later, the Netheads would
reproduce, and when they went looking for rattles and Lego sets, Bob and
JoAnn would be ready for them. The story of White Rabbit Toys, like that
of the Internet itself, was far from over.

The Electronic Billboard: Grant’s Flowers

Larry Grant just might be doing better at the moment than the
Lilienfelds were. He was selling flowers, and what better merchandise
existed for grad students who were alone at the keyboard in a dark
office at two o’clock, and who had forgotten their girlfriends’
birthdays?

A newsletter publisher named Rosalind Resnick—a former staff reporter
for the _Miami Herald_ and the author of an Internet business guide—was
grossing more than $20,000 a year in subscriptions and expecting to do
much better in 1995.[2.4] And her media-oriented newsletter helped pave
the way for a lucrative consulting business. I also knew of a network
expert named Gordon Cook who was able to jet to a three-week research
expedition in Moscow at his own expense, and who lived satisfactorily on
the revenue from _The Cook Report on Internet_ and related
activities.[2.5]

Grant’s Flowers, however, was more of a typical business. Larry Grant
wasn’t a writer. And his work was not as network-related as that of
Resnick and Cook; unlike the latter, he hadn’t evolved into a
net.personality on some key mailing lists. Instead the word was that
Larry Grant just paid his $28 a month to an electronic mall—a collection
of stores that shared a common subarea of the Net—and sat back and
watched his fax machine spew out orders. Grant might not be Davy
Crockett in terms of action, but certainly in terms of fame he was
coming along. He had appeared as a success story, after all, on the
front page of the _New York Times_ business section.

As I wended my way through the Net to Grant’s Flowers, I passed through
an area called Branch Mall. A logo with a tree branch greeted me. I saw
listings for enterprises ranging from cosmetic sellers to H & H Logging
and Timber Company. Under “Flowers, Gifts, Foods,” I didn’t see just
Grant’s listing. I saw White Dove Flower and Gift Shop, Flowers on
Lexington, Exotic Flowers of Hawaii, Bonsai Boy of New York, and half a
dozen others. Bob Lilienfeld was skeptical about cybermalls, and right
now I could see why. With all this competition, could Grant’s make money
off the Internet?

Lilienfeld had reminded me that traditional malls and the cyber variety
were different, and I understood. If I wanted to shop for books, I could
brave traffic to reach Springfield Mall, a large collection of shops
maybe ten miles from me in the suburbs of Washington, D.C. Springfield
would be worth the drive. I could visit four stores right within a
five-minute walk of each other—Brentano’s, B. Dalton, Walden, and Crown.

The Net, however, was also different. I didn’t have to drive anywhere. I
could just use a powerful search engine such as Lycos, key in
“bookstore,” and watch name after name pop up on my screen. Lycos
demanded just a little technical savvy. But easier alternatives would
come along. As if that weren’t enough, Netfolks put together lists of
activities on the Internet, and often they included commercial
categories. I’d found White Rabbit not through advertising but through
the Yahoo list out of Stanford University, on the other side of North
America. Distance just didn’t matter. So could the shopping mall
metaphor truly work out to the benefit of merchants such as Larry Grant?

Branch Mall at the very least had set Grant up in style. The opening
screen was attractive and helpful to buyers, with such basics as:
“Different areas of the country sometimes have different prices or may
be unable to supply certain flowers. For example, New York City has high
rents and costs of doing business, so flowers are more expensive
there....” And then below I saw a list of the offerings—for example,
“One dozen boxed long stem roses. A fragrant classic. $49.95 to $99.95.”
In the virtual version of the White Rabbit toy store you couldn’t rattle
the toys, and in Branch Mall you couldn’t smell the roses, but like the
Lilienfelds, Branch Mall had been generous with pictures of the
merchandise. I loved some little touches. Branch had given Grant a
reminder service into which you could key your spouse’s birthday or some
other date, before which an e-mail note would be sent to jog you to do
your duty.

The selection was varied. You could order everything from the roses to
“a get well soup cup containing button mums, daisies, mini carnations,
standard carnations, monte casino, statice, and a package of chicken
soup. $26.” All in all, I felt that this area was even better laid out
than White Rabbit Toys, where the opening page, though far, far above
average, didn’t communicate quite as much information as I’d have liked.
As with White Rabbit, you could order online by filling out an
electronic form.

Missing from the virtual version of Grant’s flower shop, however, were
the customized links that helped give the White Rabbit Toys its
personality and made it a true part of the Net. If Larry Grant had been
as at home in cyberspace as Rob Lilienfeld was, he could have added
links to love-oriented discussion areas or to poetry—perhaps even the
Shakespearean variety.

But instead this Web page was serving just as an electronic billboard
with an ordering mechanism. I didn’t even see a photograph of the store.
When the _New York Times_ published a photo of a Mosaic screen, it had
superimposed a picture of Grant amid his flowers and dressed in an apron
with an FTD insignia. Couldn’t a similar photo have adorned his Web
area?

For that matter, the store didn’t even offer an electronic mail address,
just a phone number for customers with questions. This isn’t to
criticize Larry Grant. He was not an honorary techie as Bob Lilienfeld
was. Like Lilienfeld, however, Grant was an intelligent, diligent
Midwest businessman who saw the Net as an opportunity.

Wild talk _about_ Grant notwithstanding, he wasn’t a braggart—simply a
proud family entrepreneur. I learned that Grant’s Flowers was actually
part of a mini local conglomerate. “We’ve been here since 1947,” he
said, “and my folks started farming and selling produce by the side of
the road off a kitchen table. We’re now a million-dollar business and
have many facets. We have a flower and gift shop, and the front of the
building is beer and foods. We farm 131 acres.” Two brothers were in the
business, and so was his eighty-year-old mother. “She runs the flower
and gift section, and I run the rest of the retail sales and my brothers
do all the growing and production. We’ve got two acres of greenhouses
growing plants for spring sale or gardeners. It’s a very diversified
operation.”

Grant clearly wasn’t making a living off the Internet alone, despite a
good start. “We got online in February just before Valentine’s Day and
we received forty orders that week. In the first ten days we had over
2,900 look in on our electronic storefront. Then it dropped to one or
two orders a day, and then we got to Mother’s Day and had a high of
forty in one day. Currently we’ve increased from one or two to six, in
that range.”

When I asked what his current Net-related gross would be per year, he
roughly estimated it at perhaps $15,000 or $20,000. That was enough to
make the Web area well worth his time, but this was hardly a tale of
instant riches. I remembered a magazine ad—for would-be providers of
Internet services—that showed a mustached man beside a Rolls or
Mercedes. Larry Grant was a Web merchant, not someone hooking people up
with the Net. But I wished that the get-rich-quickers of all stripes
could see Larry Grant as a realistic example of the Net’s promise. The
gold might come eventually, and it was worthwhile to chase after it by
going online, but, for most people, the big money wasn’t there yet.

What’s more, costs for newer customers of Branch Mall were higher. Grant
had been the first merchant there and enjoyed a break. Now Branch was
charging thousands a year for Web areas that included elaborate
programming and creative work.[2.6]

Larry Grant, in any event, believed in the Net and in the Mall itself.
His virtual operation wasn’t costing him _that_ much, and I suspected
that even with somewhat higher expenses, other tenants might do fine in
the end if they were in the right business. “Number one,” Grant said,
“we don’t have to take and buy more inventory. Number two, we don’t have
to have a bigger facility. And number three, we don’t need a sales
staff. We can do with the staff we have in handling these orders. It’s a
neat way to find new business. I don’t have to handle any of the
products directly. The customer does all the ordering through the
company in his area and it’s shipped from the company to them, and I get
my commission check at the end of the month.” He liked the concept so
much that he started a Fuller Brush franchise on the Net. The same key
principles applied: No inventory to worry about and no sales staff, just
some dealings with Branch and orders emerging from a fax machine.

Merchants like Bob Lilienfeld might fare well without a cybermall
involved—they knew how to spread word about themselves on the Net by way
of newsgroups and mailing lists—but I could also see the possibilities
for people such as Larry Grant as long as they kept their expectations
to a reasonable level. Grant himself didn’t view the other flower shops
at Branch Mall as direct competitors; he depicted himself as more of a
general florist than the others, what with their specialties in Hawaiian
flowers and the like. Certainly a good cybermall, like the
brick-and-concrete version, needed a good tenant mix—with a toy store
not appearing on the same screen as, say, a _sex_ toy shop.

If that right mix wasn’t around, why have the mall in the first place?
While it was true that the Net shrank distances, it did take time to
move from screen to screen at typical modem speeds. And yet, reflecting,
I could indeed see a future for malls. Even when search engines were
easier to use, people might still not avail themselves of
them—preferring to browse instead. So the mall concept might well endure
to the advantage of people like Larry Grant.

All kinds of people itched for their percentages of the cybermall
business. Jon Zeeff, the mall operator who had set up Larry Grant with
his electronic billboard, had once written medical software. David Fry
was a Harvard Ph.D. in computer science, came from a family in the
printing business, and ran an offshoot called Fry Multimedia. Ann Arbor
wasn’t Silicon Valley, but just in that one university town, at least
three local business people were on the Web in a serious way, if you
included Bob Lilienfeld. Like him, Fry wisely thought in the long term.
Drumming up business from well-known brands such as Ragu spaghetti
sauce, he did not promise an instant audience in the millions. He urged
companies to go on the Web, experiment with interactive advertising, and
make their mistakes _before_ the Net became a truly mass medium for
Madison Avenue.

Some get-rich-quickers, of course, also were jostling for virtual
tenants; even Canter and Siegel showed up by way of an area called
Cybersell, and I enjoyed the irony. C & S had carpet bombed thousands of
newsgroups with the same message—while encouraging other merchants to
ignore conventional Netiquette—and yet now they were also relying on the
more focused approach of a Web area.

Phone companies, too, wanted to run malls on the World Wide Web. And
that created problems for some. While the Net might use their phone
lines, many of these corporations felt out of place in an anarchistic
environment over which they had far less than the accustomed amount of
control. In the mall business they would be competing against nimble
entrepreneurs like Zeeff and Fry. Still, phone companies could take
advantage of their existing networks to one extent or another, and if
the Yellow Pages were going online in a new incarnation, then the Baby
Bells and AT&T wanted their share of the business. Of all the
mall-related efforts in early 1995, the most ambitious may have been
from a phone company, MCI. It exemplified—as I soon discovered in the
most direct of ways—both the best and the worst of Big Business on the
Web.

MCI’s Giant Cybermall and the
Search For Darlene

MCI and the Internet had A History. The Net used phone lines from many
companies, but MCI had long been one of the major players here; some 40
percent of the Internet traffic in the United States passed over its
cables, and nowadays the senior vice-president of data architecture was
none other than Vint Cerf. As much as anyone he was Mr. Net, one of the
founding fathers. MCI also employed the head of a standard-setting body
called the Internet Engineering Task Force. Unsurprisingly, MCI
marketers were coming out with statements in the vein of: _When you
think Internet, we want you to think of us._

I asked a product manager how much of the Net-related commerce he could
envision involving an electronic marketplace from MCI. Well, he said,
MCI had around one-fifth of the long-distance business in the U.S.—and
why not the same share on the Internet?

Clearly, however, if MCI wanted to woo the Larry Grants of this world,
it faced a major marketing problem. Just like Jon Zeeff, it would have
to sell business people on the Net as a vehicle for their messages; and
that meant _lots_ of education, not just hype. MCI, moreover, was
offering a range of services far, far broader than Zeeff’s. In an
MCI-perfect world, you would advertise your business by way of
marketplaceMCI. Prospective customers on the Net could browse through a
giant online directory and follow a link to your electronic storefront.
MCI would cleverly lure them to its area. People would be able to
retrieve voice phone numbers in far-off cities and enjoy other
information services for free.

On MCI’s planet, you’d of course use internetMCI for your electronic
mail and your Web browsing. You also could hold video conferences during
which people saw not only each other but the same contract or
spreadsheet, which they could jointly modify even if they were thousands
of miles apart. You could even receive updates on your pet news topic by
way of MCI—just the ticket for keeping up with competitors or with a
favorite athletic team.

Not all of MCI’s new services related to the Internet. But like
marketplaceMCI, many did. And even with 30 million people hooked in by
way of e-mail if nothing else, public ignorance was massive. Larry
Magid, a computer columnist, observed that even a single TV show such as
_Home Improvement_ could attract greater numbers. If MCI wanted to enjoy
volume befitting a phone company, then, it had better prepare for some
major evangelizing—about both the Net and non-Net services. MCI tried
the broadcast model in the most traditional of ways. Splashy commercials
aired on national television. They starred a fictitious publishing
company, Gramercy Press, whose president, Peter Hoffman, had a _big_
crush on MCI. Whether the service was video conferencing or electronic
mail, Hoffman was itching to open his wallet for it.

Darlene Davis was the character with the most air time, the hip young
receptionist who was waging a valiant battle to get Martin Banks, the
resident technophobe, online. If this portly old crank of an editor
wanted to read the latest memos from Darlene, then he had better plug in
his computer. Curtiss Bruno was the sales manager with his heart on his
quotas and Darlene. MCI’s electronic services could allow him to achieve
at least the former goal. Nowadays Darlene happily used e-mail to help
stay out of flirting distance with him. Ellen deRosset was the resident
intellectual snob and a Net browser. Reginald Gales used MCI’s news
feature to keep Martin up on cricket scores. Marta Dragelov was an info
junky in keeping with her duties as a fact checker.

In a country where fantasy and reality often turned into one big mush,
where O. J. Simpson movies could go into production before the end of
the murder trial, where legions of commercials aped news programs, where
the Speaker of the House would soon be hosting a cable TV showing of
_Boys Town_ after having touted orphanages as a major solution to the
welfare problem—in a nation like this, it was as inevitable as a $1
million book deal for O.J. that the mythical Darlene would draw job
offers and marriage proposals from people wanting to be part of the fun.

“These were breakout and breakaway characters that took on a life of
their own,” said Mark Pettit, the MCI public relations man who was
handling Gramercy matters. What’s more, the company’s advertising
agency, MVBMS, hadn’t just tried to make Gramercy real in the real
world; the agency people had also made the characters real in the
_video_ world by way of an introductory commercial that looked like a
preview of a new fall series.

Having conquered TV, then, and with the Internet a main focus of the ad
campaign, how could MCI _not_ have opened up a Web area to ballyhoo the
same services that Darlene was pushing on the tube? The commercials had
whetted interest in the characters. And now MCI would see if it could
satisfy this curiosity while also passing on more details about its new
line of services. “People wanted more than thirty seconds of
information,” Pettit said, “and it can be hard to give them more on TV.
What if we turned this into a real place that they could go visit? And
that’s how it came to life.” By MCI’s own estimate, more than a million
people visited the “real place” in the first six weeks or so. Even Bob
Lilienfeld dropped by. He was an MCI stockholder and wanted to keep an
open mind despite his skepticism about the mall concept—maybe he could
do business with pros like MCI’s. Lilienfeld filled out a form that
offered a two-month trial of Net-related services, and waited.

I first visited the Gramercy Press around the same time that Lilienfeld
did. The site popped up on my screen with color photos of a
perky-looking Darlene and friends. I saw a red logo, too. A small “GP”
appeared between “Gramercy” and “Press,” a nice little touch that a real
publisher might have tried. I wondered what ambitions MCI had. Might it
turn the fictitious GP into a commercial publisher someday? The screen
said Gramercy was “The World’s First Virtual Publishing House,” and
across the top I saw color photos of Darlene and friends, all looking as
real as ever. If I’d been impatient for a hard sell, I could have
clicked immediately on items such as “networkBusiness” or “MCI
Telecommunications, Inc.”

But like the rest of the cosmos, I was more keen on reading some virtual
gossip from virtual humans. In a primitive way, reminiscent of many a
best-seller, a teaser led me on. I learned that the people of Gramercy
were “working on secret projects, curt memos, random thoughts,
Machiavellian power plays,” and that I might “even browse a clandestine
love letter or two about to be sent via e-mail across the corridor.”

So I clicked, with much anticipation, on “Gramercy Press.” Against a
dark, purplish-blue sky I saw a semiornate, low-rise office building,
the same one featured in the TV commercial. Not to leave anything to
chance, a caption told me about tweeds and patches and old pipes _and_
the fact that “every one—from the receptionist to the president
himself—is online via networkMCI Business.” Despite the clichés such as
the stereotypical reference to tweeds, this site was clearly showing far
more imagination than the usual WWW area did.

“Now,” the screen told me, “click on any window and you’ll start to get
a feel of the inside workings of a major New York publishing concern.”

I chose a pane on the top floor and saw Darlene near her keyboard,
smiling away and looking as if I’d caught her in the middle of an
intense gossip session. The screen suggested that I click for audio. I
did and downloaded a short snippet. “I love technology,” she said in a
high-pitched, girlish voice, and giggled a little nervously as if to
tell the world, “Hey, I’m a real person, not an actress taping an ad.”

The text on the screen was credibly self-promotional: “I’m a combination
of a staff psychiatrist, gopher, organizer, coffee maker,
ruffled-feather soother, astrologer, party organizer, invitation sender,
flower orderer, delivered-lunch acceptor, and philosopher. Oh yes, I
also disseminate messages. A job made infinitely easier thanks to
e-mailMCI. I threw out those little pink message pads. e-mailMCI is so
much more efficient. I just click on my computer and the message gets to
the right person instantly. Whether they call back is up to them. Hey, I
can’t be their conscience, mother, and etiquette professor too. I wear
enough hats. And I have many aptitudes. For instance, I was college
skiing champ. You didn’t know that about me. Nor did you know I have a
master’s degree in medieval literature. Or that Ellen deRosset is going
to need an editorial assistant. Of course, she doesn’t know it yet
either.”

I moved on to Darlene’s e-mail by clicking on, yes, her monitor. And
suddenly I was getting another pitch from MCI in the cleverest of ways—I
saw a screen shot of a menu from e-mailMCI, complete with such commands
as “Compose,” “Forward,” and “Reply.”

Beneath the menu appeared a message list:

          E. deRosset          Short Story Submissions
          C. Bruno             Excellent Proposition
          R. Gales             Cover Art Submissions
          M. Dragelov          Interesting Facts
          P. Hoffman           Free at Last

I opened the e-mail. Ellen deRosset was complaining that “My office has
more manuscripts than the Library of Alexandria—I’m running out of room
for me. Could people submit their stories over the Internet instead of
through the mail?” Reginald Gales wrote that he’d sent out a fax to
computer artists, asking for submissions; and in fact MCI was offering
to post the works of electronic artists, not just writers. Under the
subject line “Excellent Proposition,” Curtiss Bruno asked: “Hey Darlene,
want to come by and check out the romance section of our newest
catalog?” Funny. The TV commercials had led me to believe he might be
tiring of the chase. Marta Dragelov passed on some funny trivia from a
book she was researching. Peter Hoffman announced that he would be out
of the office the next week but would be keeping in touch with
electronic mail.

So, yes, I could read the same e-mail as Darlene could. But that still
wasn’t full interactivity. I wanted a two-way, and the “Compose” command
intrigued me; perhaps I could e-mail the crew behind the Darlene
character. I wrote that I was a real writer, working on a real book, for
a real publisher; could they please tell me what kind of responses the
people at Gramercy Press were getting over the Internet? _And how about
Darlene?_

“What’s she like?” I was thinking. “How’d those people choose her? Does
she enjoy computers? Has she been on the Net?” Once I established
contact with the virtual Darlene’s keepers, perhaps I could find out.

Having already snooped at Darlene’s e-mail, I went on to the offices of
the other characters. Ellen deRosset, a dark-haired woman dressed in
black, confided that she had corrected her seventh-grade teacher’s
grammar. “I read _War and Peace_ when I was fifteen. The complete works
of Balzac before I was twenty-five. I think you get the picture. So I am
not happy that I was given the assignment to edit this ‘women in sports’
book. I dislike sports rather intensely. The only sport I know anything
about, really, is fencing. But one must be flexible these days, and the
MCI Business software makes this assignment easier to handle, if not
more palatable.”

Reginald Gales told me how MCI’s e-mail and conferencing services came
in handy. One of his authors lived on a caboose in Wyoming, while
another wrote from a houseboat in Florida; “he once had a shark bite off
his TV antenna.”

Marta Dragelov, the fact checker, was an avid user of MCI’s news-flash
service, which crammed her computer with such items as, “India Asks
Phone Firms to Set Up Local Factories”—actual news stories that I could
see while clicking on them. Peter Hoffman was away at home and working
in his pajamas. Martin Banks, the technophobic editor, said he was
“being tutored on the wonders of MCI electronic office ephemera by none
other than Miss Ellen deRosset.” He hoped that she would notice his new
pair of wing tips.

The real payoff for readers was in Curtiss Bruno’s office. Wearing a
striped shirt and a tie and looking like an incurable office politician,
he nevertheless held a hand over his mouth as if to say: “Maybe I’d
better shut up before I spill too much.” Oh, Curtiss, why bother? I
could tour an electronic version of the not-quite-completed winter
catalogue—with listings of fiction, visual arts, poetry, and nonfiction.

All categories carried dates older than the Web area itself—MCI was
apparently relying on imaginary contributors to prime the pumps. “Ivana
diTommaso’s” background just seemed too _New Yorker_-ish. She had “grown
up in Bologna, Italy, and Grosse Pointe, Michigan” and had “developed
from a quiet film student” to “one of America’s fine short story
writers.” If she existed, the electronic catalogue at the Library of
Congress had yet to note it when I made a short detour by way of my
software’s task-switching capability. Not that I trusted the catalogue.
A branch of Random House had published my first book, _The Silicon
Jungle_, yet it was missing from the LC catalogue that day; and for all
I knew, maybe the librarians had also neglected the accomplished Ms.
diTommaso. I charitably allowed for the fact that she just might exist.

Her story, “The Legend of Wendell County,” told how a county records
keeper had become a community grandmother who, not content to record
births, deaths, and divorces, tried her hand at marriage counseling and
other social workish pursuits—until one day she lost her way in winter
and turned into something else, a ghost. The bottom of the page carried
an authentic-looking “© 1994 Ivana diTommaso.”

I moved on. “The Tree House” was a story from Katy Rudder, a member of
“the first Peace Corps class ever assigned to China, where she is
teaching English at Leshan Teachers College in the Sichuan Province.”
Based on what I was reading, MCI’s artistic tastes—or its ad
agency’s—were corporately wholesome. And so were its contributors. I
doubted that Gramercy would have been the best place for the young
Burroughs or Kerouac.

Perhaps this would change, maybe Gramercy would grow more adventurous
with time, but right now I wasn’t sanguine in that regard. The
nonfiction area was a real loss with just one title, of a harmless,
theological type. I doubted that this would be the place for, say,
Seymour Hersh or Robert Caro. Like the writing, the art looked competent
and maybe much better, but, again, safely within corporate parameters.

The most cautious contributors were MCI’s lawyers, or whoever else had
written the legalese for one Web site. All writers and artists had to
send in releases saying they wouldn’t sue MCI for using accidentally
similar material. The lawyers warned, “All work that is submitted
electronically over the Internet needs to be accompanied by a hard copy
of the release form, sent in separately by postal mail. We will not look
at any work placed on our server until we have received the hard copy of
the release form. All files on the server older than 14 days, for which
we have not received a release, will not be reviewed....” I remembered
the essay on theology. It was uninspired enough for an attorney other
than Scott Turow to have written it, and sure enough, the author’s note
said he was “happy with the practice of law.”

Despite the less-than-striking short stories and the soporific essay, I
loved the sparkle of Gramercy Press as a whole. I recalled an area on
the Web known as Bianca’s Smut Shack. Its creators let you get inside
the head of a virtual woman, let you know what books she read, what
movies she watched, what records she listened to, and you could add your
own opinions. At the time I’d told the Shack crew, “Watch out, folks.
Don’t be surprised if a big company creates characters in an ad where
_everyone_ buys the right products.” Well, it had happened. And MCI and
its advertising agency had done many good things that people with their
resources could more easily accomplish.

Building Notre Dame, thousands of workers had pieced together the stone,
fashioned the gargoyles, assembled the stained-glass windows. And the
MCI Web area, while hardly art, was somewhat like a cathedral. The
area’s masterminds had bungled in some ways, but they had used sheer
staff power to toil over countless details.

I was sorry when Mark Pettit told me that some Real People in Publishing
had hated Gramercy Press. Didn’t they get it? Granted, the publishing
company was stereotypical to the point of being self-satirizing. But so
what? I was no more expecting MCI to be a first-rate publisher than I
was expecting Random House to lay fiber-optic cable.

As a display of the Web’s potential to attract a mass audience, of
course, the Gramercy endeavor had triumphed. For consumer business on
the Net to take off, ads would have to be a complete departure from
those on television, and MCI had done just that—even if it was able to
benefit from characters from the older medium. Many small-timers could
never have discovered an actress as perfectly suited to play Darlene as
Katy Selverstone was. This was a real coup. MCI was brilliantly drawing
in a big crowd through a skillful interplay of television, print, and
the Net.

Selverstone herself had become a living ad for MCI, drawing stare after
stare as she walked down the Manhattan streets. Her Gramercy role was a
real tribute to her acting ability. _Entertainment Weekly_ described her
as not “much of a gadget-head. ‘I’ve got a 12-inch, black-and-white TV
that emits a faint gaseous odor,’ she says. ‘And I have to change
channels with a pair of pliers.’” The word from MCI was that she’d just
bought a computer and would herself be on the Net. Advertisers hired
models today on the basis of looks and I wondered if, in the future,
they would consider the ability to give good chat online.

A major problem, however, arose with this scenario in MCI’s case. While
I hadn’t asked for an interview or e-mail from the real Darlene, I had
yet even to hear from her handlers after six weeks. These people had
wooed me with a first-class Web area and encouraged me to write in, and
yet they had then ignored me except for a little boilerplate from their
Darlene-bot, who said she was busy coping with “emergencies.” The MCI
media crew reinforced my skepticism; only after a series of phone calls
was I able to pry basic information. On a day when Pettit solemnly
promised he’d talked to me, he was off holding a press conference for
the _Wall Street Journal_ and the other usual suspects without alerting
me about the postponement. Clearly this was a big company focused on
other big companies, and I wondered if the small merchants in the Web
area might suffer if they entrusted their fates to MCI. I myself was not
just a writer. I made it clear that I was also a customer of MCI Mail,
an electronic mail service to which I had subscribed for a decade.
Perhaps someday I might even want a Web area through MCI. And this was
the treatment I got?

If MCI slighted me—a writer-customer who spoke out in print and on the
Net, and who had many friends there—how would it treat the Larry Grants
of the future? I thought of the elusive, virtual character who had asked
me to write to her. In a metaphorical sense, small merchants might
futilely spend their days searching for Darlene. Now I wondered about
Bob Lilienfeld. How was he coming along with his own information
request? Was there _any_ chance that White Rabbit might end up in an
electronic mall after all? Lilienfeld, albeit not a mall booster, was in
many ways a good prospect since he was so Net oriented and could
appreciate a good deal. Why, he even owned stock in MCI.

Efficiently, however, MCI had alienated Bob Lilienfeld. Just like me, he
had not heard a peep out of the company, even after filling out a form
for his two months of trial services. He had followed up with three
e-mail notes to an address set aside for prospects like him. I told
MCI’s media people about this mini-debacle and was assured that someone
would contact Lilienfeld. But after several weeks, no one had. MCI was
nicely apologetic, of course. Mark Pettit and colleagues reminded me of
the huge number of people who had replied to the Gramercy Press ad. They
said, too, that MCI technical people were busy at work answering
questions, while creative types handled the correspondence for Darlene.
But they were missing the point. This was a massive advertising
campaign, and they should have planned for success as well as failure.

The issue _should_ not have had anything to do with corporate size. MCI
could have requested zip codes and states and sorted out Darlene’s
e-mail in that way—for area sales reps to answer if her handlers in New
York were swamped. In fact, the form that Lilienfeld filled out did ask
for his postal address. It also inquired, “What interests you?” so that,
during the two-month trial, MCI could mail him news stories through the
new automatic clipping service. “You can choose any topic: your
competition’s advertising, the future of your industry, or southwestern
cooking, anything,” MCI had assured him. And yet, after six weeks, he
hadn’t received a single call or piece of literature.

As if that weren’t enough of an outrage, MCI’s fees might overwhelm many
small business people. MCI wanted to charge some $2,000 a month for
getting them on the World Wide Web—or at least several times what many
independent malls would have billed. Yes, MCI talked about adding value
through its brand name and through customer draws such as directory
services for the Net and for voice. It would even line up copywriters
for the storefronts. But what good would this do merchants whose volumes
simply did not justify such expenditures? Pettit reminded me that a
quarter-page listing in a phone directory cost $2,000. But that wasn’t
true in many areas, and most merchants did not take out that much space
anyway. Even then the typical business person might hire an extra clerk,
and perhaps have money left over for advertising with a smaller
cybermall. That, of course, was projecting into the future. After all,
even Larry Grant wasn’t grossing more than $15,000-20,000 a year at the
time, and the Lilienfelds had a long climb ahead to reach that level.

Perhaps MCI would learn. I still loved the sparkle of the Gramercy
area and hoped that it would thrive in the end. Regardless of my
doubts and frustrations, I hadn’t anything against the people of MCI,
especially Mark Pettit, who, despite his absentmindedness, had
actually been more helpful than the others. MCI wasn’t Canter and
Siegel. It hadn’t disrupted Usenet. As long as it paid its own way and
did not take advantage of its Net connections in ways that stifled
competition—Washington needed to monitor MCI closely—then it could
actually help the average Net user. The greater the volume on the Net,
the greater would be the virtual pipeline and the lower the cost for
everyone. So, far from disliking MCI’s interest in the commercial
promise of the Net, I still saw plenty of potential here. MCI simply
needed to understand the obvious. If its electronic marketplace were
to succeed, then the company must price its services more
realistically and not keep customers searching for Darlene.

Federal Express and Right-O-Way:
Absolutely, Positively on the Net

A FedEx woman called me up and asked what the people in Memphis could do
to retain my business, which had plummeted to almost zero volume.
“You’ve given me great service,” I said, thinking of all the
foot-to-throttle occasions when FedEx had picked up manuscripts on
deadline. “But you see, I’m on the Internet nowadays. _Everything_ for
my current book project goes ever the wire.” I was working on a guide
telling how to lobby for one’s political beliefs online, and the
publisher had even received the book proposal via the Net. Lots of
people were doing the same, not just with the Net but with commercial
services and fax. On legal lists, some lawyers were debating the
validity of electronic mail for business matters, but the new technology
would quiet the discussion soon enough when foolproof, digital
signatures could establish the identity of the sender.

No one needs to weep for FedEx, United Parcel Service, and the rest,
however. The typical computer is a medium-sized box full of parts that
come in much smaller boxes, such as a disk drive or a modem. And, as
shown by the thickness of _Computer Shopper_ and other magazines that
cater to computer users buying from afar, FedEx and similar services are
thriving. That is just one example. High-tech companies, especially the
network kind, want reputations for reliability and fast turnarounds.
They love the FedEx slogan: “When it absolutely, positively, has to be
there overnight.” Courier services are godsends for corporations that
rely on just-in-time delivery to reduce inventories of spare parts. If
nothing else, this principle appeals to manufacturers with slim
inventories. Also, more and more people are working at home. At the same
time, upscale consumer magazines abound with ads touting merchandise via
express, everything from steaks to flowers.

The real question, then, isn’t how to downsize but rather how to cope
with the deluge of business in small packages. And Federal Express views
the Internet as among the more promising of many possibilities.

For years, FedEx used its own network to set up computer links through
which high-volume, Fortune 500 companies could request pickups, track
shipments, and receive invoices. First, FedEx communicated with
mainframes. Then it began supplying some customers with personal
computers; eventually, some companies shipping as few as three packages
a day could qualify. “We started with the biggest customers first and
then extended that service to smaller and smaller companies,” said
Robert Hamilton, a marketer at FedEx dealing with information matters.
The next move was supplying tracking software through which people could
use their own machines to dial up FedEx. Step by step, FedEx was working
to get almost _all_ customers online to its computers—even the operators
of small home businesses.

The Internet could play an important role here because it is the closest
thing to a universal computer network. By the mid-1990s people in the
air freight business caught on to the advantages of the Net over the
proprietary networks in many cases. The Internet reached scores of
countries, no small advantage in an internationally oriented business,
and planners could use the Net’s volume to help slash the costs of
telecommunications _and_ improve service to customers. Right-O-Way, a
freight forwarder in Tustin, California, was among the Net pioneers.
Back in 1992 the company had figured out how to use customers’ personal
computers to print out bar code labels.

With portable radio-frequency scanners linked to the firm’s mainframe,
Right-O-Way’s workers could track shipments for customers—could, in
other words, offer the same services that Ex could. Right-O-Way’s
customers dialed up the company directly rather than through the
Internet. But in 1994, Martin Hubert, vice president of information
systems, hooked Right-O-Way into the Net for customers wanting to use
it. He spent just $1,000 on additional UNIX software, modems, network
setup charges, and programming time, and $350 a month in
Internet-related bills.

“Some customers have tried it already,” Hubert said. “We have sales
people use the Internet to access shipping data. Our advanced overseas
partners can access our computer directly for e-mail, tracking, and
tracing. Customers like BMW, ClothesTime, and Packard Bell access our
computer and save money on long-distance charges from overseas.”[2.7]
Those companies could reach the Right-O-Way computer directly, getting
immediate answers while they were online. Using the Net, they could even
schedule shipments. Right-O-Way told me that it protected account
numbers by requiring customers to use passwords that they received
through sales reps and ways other than the Internet.

What’s more, the company served even customers having only the most
basic of Internet connections. Yes, you could Telnet into the
Right-O-Way computer system on the Internet—could issue commands as if
you were at a keyboard at headquarters. But if you lacked Telnet
capabilities and didn’t mind the delay, you could also send electronic
mail messages in the appropriate format to track shipments or issue
pickup orders.[2.8]

Around the same time, FedEx and other industry giants were gearing up to
do business on the Internet. The Net, of course, wasn’t the only
possibility. Federal Express by then was an old hand at using its own
network, which at the time accounted for more than 50 percent of the
packages shipped. It was also distributing Windows and Mac software to
enable tracking through the FedEx net. Just the same, in December 1994,
after having earlier experimented with the Net for the distribution of
press releases, FedEx turned to the Internet’s World Wide Web as a way
for customers to track packages. Within FedEx’s Web area, they could key
in the number of the package and get the latest information.

I checked out the Web service. At www.fedex.com I saw “FedEx” in big
purple and orange letters, along with a short, easy menu that led me to
electronic forms. A detour offered “Interesting Facts about FedEx!” It
was the “world’s largest express transportation company,” had 1994
revenues of $8.5 billion, employed “more than 505,515 worldwide,” served
191 countries, owned more than 400 aircraft ranging from 32 Fokker F-27s
to 5 Airbuses and 13 McDonnell Douglas MD-11s, operated “more than
32,560 vehicles, and shipped an average of more than 2 million packages
each day.” Another menu item could tell me about pickup availability. If
I typed in the time I would have a shipment ready to go, my zip code,
and the destination code, among other items, then FedEx would tell me
how soon it could deliver the package using Priority Overnight Service
or alternatives.

Right now, however, I wanted to learn the whereabouts of a test
package—containing nothing more than Robert Hamilton’s business
card—that went out under airbill number 50044562. It was a no-brainer. I
chose “Select Track a FedEx Package” and keyed in the number. Almost
immediately I learned when a courier had picked up the package and when
it had left Memphis. And eventually the Web would pass on other facts
such as the name of the driver at the destination, the delivery time,
and who signed for the package. An idea hit me. When you filled out an
express form in the future, perhaps you could give both your recipient’s
e-mail address and your own. Via the Net, a service could tell the other
person that a package was on the way—and after it arrived, you’d
automatically receive a receipt.

Even as the FedEx area existed now, however, it was serving customer
needs well. Yes, I appreciated the flash of MCI’s efforts, and I
understood why Darlene and friends were attracting many more people than
the courier company was right now. But compared to MCI, FedEx left me
feeling _better_. Those modest little electronic forms, the ones that
would let me track packages and check out Ex’s service availability by
location and time, treated the customers as individuals and responded in
seconds. MCI, however, ignored Bob Lilienfeld, who, disgusted, later
sold his stock.

On top of everything else, MCI, which had vastly more programming talent
than FedEx did, had missed out on some major opportunities for
interactive software. I could imagine a small company keying in a
description of its telecommunications and network requirements and
getting a series of at least basic recommendations. On a
package-by-package basis and in the most private of ways, FedEx was
doing this already—since its forms queried you about your shipping needs
of the moment and then told you what services were available. The people
at MCI weren’t dumb. They could turn around their operation in a
flash—they might have done so by the time you read this—but in terms of
customer service FedEx was clearly the winner right now.

“Five years from now,” said Robert Hamilton, “35 or 40 percent of the
customers connected to FedEx could be using the Internet.” His company
stood a good chance of saving millions in annual communications costs
and the expenses of staffing phones. “The big factor is how individuals
are connected today,” he said. “With CompuServe and America Online
galloping in the direction of the Internet, maybe that will happen
sooner rather than later.” FedEx would let customer usage, not official
corporate policy, drive its use of the Net, and that is exactly how it
should be. One way or another the Net would definitely figure in its
plans. The only question was, “How much?”

The big need now, of course, was for customers to be able to key in
their account numbers and get immediate pickups. FedEx did face some
challenges here. FedEx needed to blend the Internet into its existing
network of computers, and this complicated the security issues. FedEx
wanted to make certain that a cyberthief couldn’t go on a joyride with
an illegally obtained account number of a customer. So it was evaluating
security-enhanced software from CommerceNet, a California organization
that helped put businesses on the Net. Meanwhile, we customers could not
use the Net to schedule shipments through Federal Express. FedEx had
offered a temporary solution: we could at least download software that
let us call up the company directly, or we could reach FedEx via America
Online or another commercial network. That would do for the moment.

Mulling over what I’d seen and heard up to now, I could not escape three
conclusions. First, it was clear that computer networks could be a help,
not a threat, to delivery companies that were trying to upgrade service.
No longer would I have to wait for an operator to schedule a pickup or
check on shipments from FedEx. The second conclusion was broader: The
Net often could be good for corporations of _all_ sizes, not just
Fortune 500 firms like FedEx. Right-O-Way had staked out its own place
in cyberspace by going for the simplest solution—Telnet and electronic
mail—rather than worrying first about the World Wide Web. The company
could add the Web later. On the Internet, with its inherent economies
for the Right-O-Ways of this world, “smaller” didn’t have to mean
“backwards.”

The third conclusion about these case histories resulted from my
comparisons of MCI and the courier companies, and it transcended the
fact that they were in different industries. Even on the Internet, good
customer service would have to be a company’s first priority and counted
even more than the technology per se. Oh, you could use electronic
forms. But unless you programmed the forms to provide the right
services—rather than simply trying to sell The Product and awe the
customers—you might actually alienate the people you were trying to
befriend. MCI didn’t understand this sufficiently. FedEx and Right-O-Way
did.

Intel: How the Net Helped Turn an
Advertising Sticker into a Warning Label

The Internet, of course, can hurt as well as help business. Well
populated with skeptical academics—whose postings often find their way
onto the screens of equally skeptical journalists—the Net is a good
place to learn about scams. Legitimate companies, of course, needn’t
worry: They will benefit as word of their successful products spreads,
and the Net excels as a conduit for rumor control. Should there ever be
another Tylenol scare, you can bet that publicists will use the Net to
get the truth out. Even legitimate businesses, however, can feel the
wrath of the Net if they err—as Intel, the chip maker, found out in the
ugliest of ways after it released the Pentium chip.

The Pentium chip was the new flagship product, the speedster that would
let PCs impinge on minicomputer territory. But that wasn’t all. Intel
envisioned the Pentium as the perfect chip for computers aimed at the
home market. No longer would Mom, Pop, and The Kids poke along with
computers weaker than those at the office. Thanks to Intel, they would
enjoy glitzy cartoons, educational programs, and other multimedia
offerings in full glory on their machines at home. Intel launched a
major TV campaign and persuaded scores of computer makers to adorn their
boxes and ads with “Intel Inside” stickers. Intel was looking ahead to
millions of dollars of Christmas-related sales. At the time, I suspect,
the Internet didn’t figure that prominently in Intel’s plans. Its Net
area was hardly as dazzling or as ambitious as those of many other
companies. That would change.

The trouble started when a mathematics professor in Virginia found that
under certain conditions, the Pentium chip would make mistakes in
arithmetic. There at Lynchburg College, Dr. Thomas Nicely couldn’t
believe his screen. To his amazement, he was able to verify that the
chip, not the human, was at fault here. In October 1994 the professor’s
“Bug in the Pentium” memo went out over the Internet. It circulated
rapidly from mailing list to mailing list, from newsgroup to newsgroup,
as well as on commercial nets such as CompuServe and Prodigy.

Pentium-hostile messages flew back and forth between scientists,
corporate executives, consultants, and other influential people, who,
thanks to the Internet, could share complaints more efficiently than
ever. Intel tried some damage control via the Net and in press
statements. The heat reached the point where the head of Intel asked a
underling to issue an apology and a technical explanation. The message
betrayed corporate panic, pure and simple. “I am posting from my home
system,” Richard Wirt, Director of Software Technology, prefaced a
weekend note. And then came an “I am truly sorry” message from Andy
Grove, President of Intel. In various statements Intel assured customers
that the average computer user would typically run across the problem
once every 27,000 years. The official line was that nontechnical people
needn’t worry. Intel announced it would replace chips _if_ people could
show that the defect could harm their work.

That still didn’t placate the Net and the media. Netwise reporters at
papers such as the _Washington Post_ and _New York Times_ and at
_Newsday_ warned the thousands of Christmas shoppers who were about to
buy $2,000 Pentium machines. Billions of dollars were at stake here.
Computer makers had already moved millions of Pentium machines, and IBM
came out with a statement saying that it would replace defective
chips—even though Intel kept claiming that the nontechnical need not
worry. It didn’t help when shoppers learned that Intel knew about the
Pentium’s defects as early as June.

What most threatened the Pentium, however, may have been the humor. It
started on the Net and, via mailing lists such as On-Line News, reached
major newspapers. David Letterman started cracking jokes. Politicians
and chips had something in common. If still quite alive when Letterman
ridiculed it, the Pentium was headed toward the emergency room
afterward—given the speed with which the story was traveling around. On
the Net itself, and on the front pages, typical Pentium humor went
something like this:

    Q. “How many Pentium designers does it take to screw in a light
        bulb?”

    A. “1.99904274017, but that’s close enough for nontechnical people.”

    Q. “What do you get when you cross a Pentium PC with a research
        grant?”

    A. “A mad scientist.”

    Q. “What’s another name for the “Intel Inside” sticker they put on
        Pentiums?”

    A. “The warning label.”

Maintaining to the end that this was more of a marketing problem than a
technical one, Intel relented. It agreed to replace chips for free
without interrogating the public. What’s more, Intel expanded its
presence on the Net. It now offered a nice area on the World Wide Web
with items ranging from product descriptions to job announcements.
Still, this fiasco aside, Intel had a good reputation for quality
control, and by not shrinking from the Net community, it was responding
correctly.

Another major lesson should also have sunk in among marketers of all
kinds—beyond the obvious fact that the Internet could spread news of
flawed products. Customers throughout the world could use the same
channels to find out about geographically based price gouges. If a
software firm charged reasonable prices in the United States but boosted
price tags for Europeans, then the Net would spread the word. Software
companies might not appreciate this immediately, but sooner or later
they would. This was especially true of companies sending their products
over the Net. The Internet Adapter, the product that had proven to be so
good to my wallet, would have cost me $25 even if I’d lived in
Antarctica or New Zealand. I wondered how long it would be before the
traditional vendors of shrink-wrapped software would understand this
lesson and stop squeezing customers outside the United States. Even with
the expenses of middle people and translation factored in, the prices of
some American software products were too high in Europe. Consumerism on
the Net just might make the marketplace more sane.

Other Hazards For Business People

Not surprisingly, the old sixties people saw the Internet as a victory
of smallness over big corporations. Little companies could use the Net
in new and imaginative ways and woo prospects thousands of miles away.
Some enthusiasts promoted the Net as a powerful weapon for individuals
who hated life in sluggish, bloated corporations.

Still, the Net might not always be a Nirvana for small entrepreneurs.
Consider the Lilienfelds. What if toy companies decided to sell on the
Net directly, for example? The Lilienfelds themselves could still fare
well since they were working hard to become known for personal service.
For example, if a toy weren’t shown online, Bob might even scan in a
photo from a wholesaler’s catalogue and e-mail it to an interested
buyer. And he and his wife were planning to make themselves a
conspicuous presence in relevant newsgroups, while respecting
netiquette. But not all of the small merchants would be as astute and
dedicated. I suspected that many bankruptcies lay ahead.

Other problems might hit large as well as tiny companies. Many customers
refused to give their credit card numbers online; in fact, many stores
didn’t even _want_ them. The Net wasn’t entirely secure. Theoretically,
snoops in a number of locations could intercept orders and pick up the
MasterCard or VISA numbers with software that looked for common data
associated with credit cards. I regarded this as a temporary problem.
Lilienfeld had dealt with it nicely by letting people—at least those in
the United States—phone in their credit card numbers for free. The
numbers would remain safe in White Rabbit’s computers, ready for future
transactions. Besides, as Lilienfeld pointed out, it wasn’t worth the
trouble for thieves to keep a tab on small stores like his.

Bigger businesses, however, were right to worry, and solutions were on
the way. Popular browsers such as Netscape, for example, were coming
with security features. Customers would be able to effortlessly transmit
their credit card numbers in encoded form.

What about the problem of customers without sufficient funds to pay for
merchandise? Some Web merchants could almost instantly verify that a
customer had enough money in a credit account. The process would be even
easier if companies such as Microsoft followed through with plans to
team up with credit card companies. But that still left another worry
for customers—privacy.

If you use old-fashioned paper money, your transactions aren’t
traceable. With electronic money—or with regular credit or conventional
debit cards—they might be. What if you were a gay woman, lived in a
small Arkansas town, and enjoyed lesbian literature? Or suppose that in
the future you were caught up in a divorce and your wife employed a
cyberdetective to snoop on your spending habits? DigiCash, a company in
Amsterdam, thought it had a solution in the form of anonymous electronic
money that you could spend without being traced. Only your digital
banker would know for sure. The possibility, of course, gave fits to tax
collectors throughout the world. It was one of the reasons why
bureaucrats in the United States had lobbied so hard for industry to
adopt the Clipper chip, which allowed federal snoops to break its codes.
Clearly, however, the Clipper effort could _harm_ U.S. companies.
Suppose foreign governments used a similar approach—making it easier to
steal commercial secrets from American-owned multinationals?

Still another threat to business is from people who might spy on or
change data on corporate systems. Hackers got into General Electric
computers containing secrets. The solution to these electronic thefts,
in many cases, was stronger “firewalls”—electronic gateways between
public and private areas. In some instances, however, the threat was
exaggerated. Yes, in theory, hackers could turn your home phone into a
pay phone or make off with your corporate password or spy on your
electronic mail. And some hated commercial activities on the Net and
were ready to act. But by far, these were exceptions: most of the better
hackers were benign—they saw themselves more as scholars than as snoops
and saboteurs. Indeed, old-timers would not use the word “hackers” to
describe the malevolent; no, they were “crackers.”

Ironically, on the Net, the real worry isn’t hackers but snoopy
competitors, who, without necessarily breaking the law, can find out
information about prices and new products much more efficiently than
before. A rival phone company has paid thousands and thousands of visits
to the MCI area on the Web. This must be going on constantly. Earlier,
Digital Equipment Corporation offered software demonstrations over the
Net and found that its competitors were tying the machines up. More
scrupulously, companies could use powerful searching tools such as the
Lycos on the Web to seek out files mentioning rivals’ products. They
could also send the names of rivals to a computer at Stanford
University. And then whenever a company was mentioned in a major Usenet
newsgroup, an electronic clipping service would send the information
back to them at no charge. A careless engineer or marketer could
jeopardize thousands or millions in investments. The answer, of course,
is to educate people about the risks.

Not so controllable is the risk of companies using the Net to troll for
unfavorable mentions of rivals—grist for negative advertising. There is
only one solution: make better products or give better service.

                  *       *       *       *       *

Of the goods and services discussed here, a major kind is conspicuously
missing so far: entertainment. Some of the best is free. Just ahead
you’ll find a favorite of many Netfolks—the Internet Underground Music
Archive, from which you can download free samples from top hits as well
as surprises from new musicians.

                                CHAPTER
                                 THREE

    EntertaiNet: A Few
    Musings on Net.Rock,
    Leonardo da Vinci and
    Bill Gates, Bianca’s
    Smut Shack, and
    David Letterman
    in Cyberspace


Don’t count on the Ugly Mugs pushing Billy Joel off the charts, or even
showing up at your closest record store.

They’re zany, avant-garde musicians whose work is a cross between Frank
Zappa and freakish, carnival rock—not the stuff of the Top 40. But Jeff
Patterson, a thin, pale guitarist with a fondness for old jeans and
green-topped sneakers, can still spread the word about himself and the
other Mugs. Their music is on the Internet. Fans as far off as Turkey
and Japan can dial the Internet Underground Music Archive run by
Patterson and his “co-czar,” Rob Lord. Hundreds of musicians are
suddenly in cyberspace. For just $100 a year they can pay IUMA to post
cuts from their music, complete with information on how you can send
away for the CDs and tapes. In fact, some have even posted complete
songs to the Net for free.

Tens of thousands of Netfolk a week dial up IUMA, making 200,000
page-accesses—perhaps a third of the attention that _Playboy_ gets, but
still one of the best numbers on the Web. That’s no small feat: The
archive more or less started in a tiny room with a bare lightbulb
dangling from the ceiling, and it is still a low-budget operation run by
two information science majors.

IUMA is just one of many delights on the Net for techies and
technophobes alike. Entertainment and culture are taking off in a major
way in cyberspace just when clueless Snubbites are deriding the Net as
artless. I can enjoy gifted but unheralded performers, from reggae
artists to banjo players. The New Zealand Symphony is online with a
digitized rendition of the national anthem down there. Imagine the
possibilities for fans of classical music in the future—the chances to
hear live performances of Tchaikovsky directly from Moscow, or enjoy
classical Chinese music from Peking or Taipei. Net.radio is already
here. WYXC, for example, a station at the University of North Carolina
at Chapel Hill, sends rock music into the ether twenty-four hours a day.

Running software called RealAudio, owners of deluxe home computers can
hear top-ten rap from an Internet site in South Korea, astrological
forecasts from England, and selected programs from ABC News, National
Public Radio, the C-SPAN cable network, the radio version of the
_Christian Science Monitor_, the National Press Club, the Canadian
Broadcasting Corporation, and a wealth of other draws whenever they
want—even weeks or months after the original broadcasts.

Just a mouse click on the right Web address conjures up a Daniel Schorr
commentary, or a feature about the Illinois reporter whom the mob
supposedly buried in concrete, or scads of other NPR offerings that I
wish I could have enjoyed when they first aired. I don’t have to bother
with tricky downloads of files containing the sound. This happens on its
own.

RealAudio sounds rather muffled right now, at least on my computer, as
if the technology is a throwback to 1920s radio. But sooner or later it
will make FM stereo seem antediluvian.

Consider, too, the diversity of programming from grassroots people who
can broadcast at a fraction of the costs of even peanut-whistle
stations. Thousands of mom-and-pop sites—unencumbered by the Federal
Communications Commission, unless the nanny faction wins out in D.C. and
cracks down on the Net—may be online in the next year or two. What
happens when unpopular political beliefs spread around this way? Will
the Oklahoma City tragedy be invoked to squelch RealAudio and
equivalents?

Cheerier possibilities may arise. Someday you might go hiking in the
middle of the Rockies and be able to tune in performances and talk shows
from all over the world through a net.satellite link; never mind the
limits of the local radio stations.

Even video transmission will be routine over the Net or a successor. And
then what? When Michael Moriarty, a TV actor, appeared in a public Q & A
session on Prodigy, the possibilities made him wonder if network
television would go the way of vinyl records. “Television,” he told the
_New York Times_, “might become the 33-1/3 of the visual arts.”

For the moment, however, the Net is Fan Central for television along
with other media. David Letterman fans and those of Jay Leno debate the
merits of their favorite talk show hosts, while major movie studios
preview their megahits with video clips. Elvis is alive and well in an
area on the Web. And just when we Netfolks are ridiculing the TV moguls’
dream of 500 channels of _Terminator_ movies, Hollywood has used our Net
to ballyhoo _Junior_—a comedy starring the Terminator himself, Arnold
Schwarzenegger. As if that isn’t enough, Hollywood has just released
_The Net_, a thriller with some evil techies; let’s see what the
marketers will post on the Web to push _that_ one. Lower on the show
business hierarchy, you can find model Danielle Ash replying to
questions, in alt.sex.breasts, about her double Fs.

Netfolks with more elevated tastes can dial up the WebMuseum, Paris, or
check out the works of new digital artists from Boston or New York or
dozens of other big cities. Obviously the Net isn’t the same as
beholding a Rembrandt in Holland and gazing into the face of a local man
or woman a few feet away. That’s screamingly clear. Stoll, the near
Snubbite, correctly notes that “Rembrandt painted real people—their
facial features and mannerisms live on today in the Dutch population.
Dressed in period costumes, I’ll bet the security guard with his war
medals and the young woman tour guide would look as if they stepped out
of one of those incredibly detailed paintings.” Moving and true.
Imagine, however, the benefits of the WebMuseum to people without the
Snubbites’ ability to jet to Amsterdam or Paris. What’s more, the Web
brings its own glories to compensate; I can view Artist X’s work, then
call up text about the person or the times; if anything the Web can
provide _more_ context than do the skimpy handouts available at most
museums.

Caviling away, Stoll also objects that computers can’t reproduce the art
exactly. But colors and resolution will just keep improving. The
Snubbites who rant about lost details remind me of the foes of
electronic books; incorrectly, given the ease of digitizing everything,
the foes worry that new technology could kill off distinctive
type-faces. But we shouldn’t preserve art and literature just by
attending to the detail work. Culture also needs a place in the public
mind; da Vinci-class art should be free, or close to it, by way of the
Net. That is surely the ethos of Nicholas Pioch. An ex-Microsoft intern
now studying economics in his native France, he is behind the WebMuseum,
Paris, the new name it bears, now that bureaucrats won’t let him say,
“Le WebLouvre.”

Within Le WebLouvre—there, I’ll say it anyway—I saw such da Vincis as
_Mona Lisa_ and _Virgin and Child with the Infant John the Baptist and
St. Anne_. I went on to look at Rembrandts, van Goghs, Cezannes, Dalis,
Klees, and Manets, among others, and to read two warnings. “If you think
the law prevents you from viewing these exhibits, you should stop now
and do something more interesting, such as flying to Paris and touring
live!” Pioch wrote. “Some companies may be trying to get a monopolistic
grab on arts and culture,” he said elsewhere, “developing a pay-per-view
logic, shipping out CD-ROMs while trying to patent stuff which belongs
to each of us: a part of _our_ human civilization and history.”

How right Pioch was. Bill Gates has just bought a notebook of Leonardo
da Vinci, and let’s hope that like some of the old robber barons, Gates
will habitually share his acquisitions with the world. But a major
difference shows up here. Andrew Carnegie and the rest did not make
their money off art and entertainment, part of Gates’ master plan. For
Bill Gates to give away great paintings and manuscripts will be like
Carnegie giving away steel. His motives may be the most ethereal, and
with a $10-billion net worth, he can afford many a donation; but a
conflict will forever arise between Gates the businessman and Gates the
philanthropist. Just which side will prevail when he dies? If not in
life, then in death, by way of his lawyers, will he have the decency to
turn _all_ his old masters loose on the Net for free viewing? No
judgments here. Perhaps that day will come. He has already agreed to
loan the notebook to a museum.

Old masters, of course, are far from the only Culture on the Net, and I
doubt that Bill Gates will be interested in buying some of the other
kind—especially Bianca’s Smut Shack. Don’t ask me if Bianca exists. The
Shack’s “trolls” swear that she does. If so, maybe a good many Netfolks
know her at least slightly. They can click on a picture to flit from
room to room of her virtual apartment on the Web, leave notes on the
walls of her virtual bathroom, enter her virtual music room to take in
the latest jazz or rock, or engage virtually in sex acts with strangers
in Argentina or Brazil or San Francisco or wherever else hormones fuel
technology.

Bianca’s proud trolls have not sold out their mascot; the virtual Bianca
lives on the Web for fun, not direct money making. But sooner or later,
elsewhere on the Net, if this has not happened already, an ad agency
will create a fictitious character who buys CDs, foods, books, video
tapes, automobiles, and other products only from hidden “sponsors”—not
open, MCI-style ones (as described in chapter 2). I’ll hope that day is
far off. The FCC has had problems enough regulating children’s TV;
imagine what could happen if supposedly educational areas knuckled under
to Madison Avenue. I’m not sure if laws are the solution here, but it
would behoove Net providers to come up _now_ with rules against that
sort of thing.

In the fun areas of the Net, other dangers lurk for the vulnerable.
Millions of Netfolks enjoy role-playing in imaginary worlds known as
Multi-User Dungeons, where they can be knights or damsels, regardless of
gender—sometimes men assume women’s roles to win more attention. At the
risk of sounding like Stoll and the Snubbites, I have mixed feelings
about the worth of MUD-style diversions.

A real potential exists for cocaine-heavy addiction—far more than just
regular Netsurfing, where you’re not competing to rescue a fair maiden
or dodge alien attacks. Stories circulate of role-players who have
kissed off good grades and careers. Up in Canada, one player got so
wrapped up in his game that my researcher found him amid wall-to-wall
trash as he struggled to balance his schoolwork and role-playing.

Just like online groups for depressed people, however, MUDs and similar
areas can bring shy Netfolks together face to face. I heard of several
romances, in fact, that the games led to. Risks notwithstanding, games
do more good than harm if players just know when to quit. Like it or
not, among millions of Netfolks, MUDs and cousins are as much a part of
the Internet as the Web and @ signs.

Of all the entertainment on the Net, however, the musical and video
kinds could most intrigue the masses as the technology takes off; with
just a modem, a reasonably powerful computer, and a $100 sound card, you
can hear the offerings of IUMA and similar areas. You don’t even need
programs such as Mosaic or Netscape if you know what you’re doing.
People with cheapie dial-up connections and no frills software can
download rock albums and the rest. Granted, the technology as a whole
could be better, and even using IUMA can tax the wallets and patience of
some. In most cases you’ll spend more time downloading the music—from a
remote machine to your own—than you will hearing it. Fidelity on some
setups may be just this side of a tin can. But that’s now. Wait.

Transmissions in the future will zip along through cable TV connections
to the Internet, or through ISDN[3.1] phone connections. Then you’ll
truly be able to use the Net as a jukebox and _hear_ what you click on
with your mouse. What’s more, even now, with the right software, you can
enjoy almost CD-ROM-quality fidelity from areas such as IUMA. Audio was
the next step up after text, of course, and, yes, video is on the way.
Techies already have mounted gigabyte after gigabyte of amateur videos
on the Net. Sooner or later, directors of little films will enjoy a
monster-sized IUMA-style archive. Perhaps Rob Lord and Jeff Patterson,
those co-czars of IUMA, will run _it_, too.

If you think that the $10-billion-a-year recording industry is a little
nervous, you’re right. In early 1994 Lord told the _San Jose Mercury
News_: “We want to kill the record companies.” He and Patterson have
backed off since then; they’ve even helped Warner and other giants set
up Net areas of their own. IUMA’s own 500-act selection is pathetic
compared to those at the largest record stores. Still, think about the
long run: The IUMA model just might jeopardize the seven-digit salaries
of top recording executives. After all, if the Net can advertise music
and even be used to take orders—perhaps with electronic forms—just what
becomes of the big studios? They themselves will sell music directly
over the Net, but with heavy competition.

The bypass-the-middle-man idea could apply in other ways. What about
radio hosts, for example? Suppose they can reach people all over the
world through the Internet, and perhaps ultimately through wireless
connections based on the Net. Will they need CBS or NBC or ABC or
equivalents as much as they do now? I can already download snippets
from, say, the Canadian Broadcasting Corporation. Too, just what will be
the fate of art dealers if so much of art goes digital and people can
discover artists on their own without leaving their living rooms?
Publishers of newspapers, magazines, and books, of course, are in a
quandary—see the next chapter on electronic publishing.

In some ways I don’t envy the big guys. IUMA is clearly wired into the
Internet, while companies such as CBS, at least at this point, are
fumbling in some respects. Many of the amateurs on the Net are actually
coming up with better offerings than are the professionals. When I
dropped by, the official Letterman page on the WWW was far from an
abomination, and yet at the same time it showed the problems here.

The page indeed was full of odds and ends about how to get _Late Show_
tickets, Letterman’s upcoming guests, his top-ten lists (the one for the
April 13th broadcast was on “Ways CBS Can Raise Money,” with number one
being “A two-hour paycheck freeze on Letterman”), and the rest. But
where were the connections with the rest of the Net, especially the many
Letterman fans out there? How about the fans’ Letterman pages? Or
relevant mailing lists or newsgroups? Perhaps they were there but
hidden, but whatever the case the cyberspace Letterman was less hip than
the one on The Box.

To Letterman’s credit, he didn’t fake things. He publicly confessed he
was ignorant of data ways. But in my opinion, his Web people could have
done better.

Moving on to the CBS home page, I saw an offer for me to “Join the EYE
ON THE NET club. That way we can send you more information about CBS and
its programs. You can also take part in special previews and other
interactive events. Fill out the following registration form and we’ll
give you a special CBS screen saver just for joining.” Oh, boy, that was
just why I was on the Internet—to end up on marketers’ lists. I didn’t
blame CBS for trying; some of Letterman’s fans would like the free
software. But surely the network could have done better.

Aaron Barnhart, who put out a good little electronic fan newsletter
called _Late Show News_, defended Dave’s people on the Net. “I think
it’s great,” he said of the official Letterman area. “All of these large
entities are trying their best to integrate with the interactive age. A
lot of e-mail gets passed that you never see, so don’t assume that just
because there aren’t any bulletin boards ... there is no interaction
happening.”

Perhaps he was being kind to his sources for his newsletter—I hadn’t any
idea. What was clear was that he’d made a second career of Lettermandom.
He devoted twenty to thirty hours a week to Letterman-related
activities. Much of his newsletter was a review of reviews (“Frank Rich
of the _New York Times_ wrote one of his standard pitiless columns last
week on the Oscars broadcast, and we quote, ‘in which the belly-flopping
David Letterman demonstrated just how large a bullet he dodged by not
moving his own show to L.A.’”). Barnhart also served as owner of the Top
10 List (“60,000 subscribers and booming”).

So what was Barnhart in it for? He was freelancing for the _Village
Voice_, and I could see where some attention might do any writer’s
career good, but if Barnhart even wanted to be on _The Late Show_
itself, he did a pretty good job of concealing that. “Attention is
great,” he said, “but it doesn’t pay the rent.” Did he send stuff into
the show? “No.” So why was Letterman so popular on the Net?
“Demographics.” Well-off computer owners just liked that kind of
program.

I checked out the Letterman page maintained by Jason A. Lindquist, an
electronic engineering student at the University of Illinois,
Champaign-Urbana, a self-described “Statistician, Smart-Ass-for-Hire,
and Mac Programmer.” I found references to newsgroup postings on such
items as “Dave instigates the feud with Bryant Gumbel with these words,”
“The great Stevie Nicks controversy of 1986,” “Madonna—Your first choice
to date your son,” and “No inside stuff on the strong guy or the fat guy
here.” And I saw mentions of the newsletter, the Frequently Asked
Questions List, and at least two Letterman-related newsgroups. CBS ought
to hire this guy.

It was time to move on to alt.fans.letterman. I did a search within
Netscape for the word “Leno” in the subject header and found a post from
an apparent Leno fan on the attack: “Everyone knows that Jay Leno is way
better than ugly gap-tooth Dave!”

“Oh,” replied one of the faithful, “you say that Jay Leno is still on
the air? Is it true that they use a wide-angle lens to photograph that
lantern jaw of his? Just wondering.”

“Letterman has more comedy in his little pinkie toe than Leno will have
in his wildest dreams,” said another Davite, “and if Letterman is so
ugly, who has all the models and top actresses flirting with him and
asking him to go out—it certainly isn’t Leno.”

_That_, not the official Letterman area, was the true Net. Just what
might await the world if the inmates actually ran the asylum and
themselves mounted a major entertainment effort rather than trusting the
corporate world. It had happened with the Internet Underground Music
Archives, and I liked the results.

IUMA

The normal story is that IUMA began when Rob Lord and Jeff Patterson,
the co-czars, met in a newsgroup devoted to supermodels. Both liked Kate
Moss, a waify Calvin Klein woman; strutting down the runways, she was
lost amid the big, bosomy knockouts favored by so many young men on the
Net. It turned out that Lord and Patterson were both from Valencia,
California, a far-north suburb of Los Angeles. They knew each other
slightly from William Hart High School, both had worked in record stores
while teenagers, and both had both been attending the University of
California at Santa Cruz. That’s the story, and it’s true.

IUMA, however, in another way, may have started not on the Net but in
the corporeal United Kingdom.

Thousand and thousands of Brits were dancing to synthesized _bleeps_,
_conks_, _cooonkks_, _clunks_, _bomb-bombs_ and _tssss-tsss-tssses_, and
odds and ends that I could never even come close to reproducing here.
The name of the music was Rave, as in “raving mad,” and by the time Lord
was in high school in the 1980s, the craze had found its way to Los
Angeles.

Middle-class white suburbanites, Latinos, Blacks, they were all
_bleep_ing and _conk_ing together, thousands of them, risking the wrath
of the fire department, overcrowding the halls, going at it from 11 P.M.
on, some dancing twelve hours on into the morning.

“No place in Los Angeles,” Lord said of the Rave halls, “had such a
peaceful coexistence as between these three groups. They didn’t say
anything. They shared the beats and feelings and the technology. And on
the Rave scene, the person in charge is the DJ, and they’re sort of the
cultural funnel. The DJs were in charge of finding these odd records
that would come from Belgium and from the UK and from Chicago, and there
were some made-in-Los Angeles things. They were hard to find, but the
DJs were responsible for scouting them out and bringing the very latest
_bleeps_ and _conks_ together.”

“So,” I asked, thinking of IUMA and Lord’s chance to bring the world to
his listeners, “you liken yourself to those DJs?”

“Yeah, yeah!” Lord said enthusiastically. “I believe IUMA is my personal
implementation of Rave’s calling. I just love working with technology
and all those kinds of things, and what Rave culture espoused was that
there’s a new revolution going on, an information revolution. You know,
one of the biggest stars of Rave music was a band called Dee-Lite. And
one of the first lines was, ‘From New York City in the age of
communication.’ And that means all kinds of communications, a shrinking
world, Internet, it means ideas and the convergence of ideas.”

Returning to the subject of his younger days, Rob Lord told me how
much he hated the Depeche Mode music that was so popular in
upper-middle-class neighborhoods like his—the kind the record stores
were selling. He wanted his music from the clubs, from the 100-copy
pressing, not from the megaconglomerates offering the likes of
Depeche. “The lyrics were terrible, and the emotions were feigned.”
I’m sure Depeche fans might disagree. The point, however, was that
Depeche music was much more readily available at record stores than
Rave was, and Rob grew unhappy with the distribution system.

Jeff Patterson, working at a music store, just like Rob Lord, was
equally disgusted. Patterson and co-workers “would sit there and talk
about who’s making all the money.” CDs cost $15-$17 at Music Plus, his
employer. Elsewhere they were around $12-$13. “And you know, we were
thinking like, ‘Where is that extra $4 being pocketed?’ You know, after
all the costs were taken out, then their manager would get paid, the
record company would get paid, people on the tour would get paid, and
then the band would finally get some money after all that, and it was
usually a very small check. So the artists that were actually continuing
to be artists were the artists that were making money; so it was, like,
this level of superstardom that was consistent and the barriers of entry
were extremely high.”

That was true in all kinds of creative endeavors, especially in writing.
I myself was amused when lobbyists representing industries such as music
and publishing would rant on and on about the need for “creative
incentives.” If business people at the megaconglomerates really
understood incentives, they would cut out their caviar, sell off the
executive jets, and spend more than a modicum on garden-variety
artists—not just the Mailers and Madonnas. When, even as a teenager,
Jeff Patterson started asking where the money was going, he was laying
some of the more important underpinnings for IUMA.

An “A” student who would later graduate near the top of his class,
Patterson wrote a school paper on another major issue: censorship. Back
in the 1980s, Tipper Gore, Al’s wife, had helped start a group called
the Parents Music Resource Center, which wanted to rate music and keep
the more nefarious offerings out of the hands and CD players of young
people. “I was a big fan of Frank Zappa and he was basically taking it
upon himself to challenge the PMRC.” The Senate held hearings. And
Patterson recalled that PMRC deemed a Zappa recording, “Jazz from Hell,”
to be sinful. The album lacked lyrics and the cover just showed Zappa’s
face. “It was obvious,” Patterson said of Tipper’s group, “that they
weren’t actually listening to the content or caring what it was. They
just kind of labeled some artists as being bad, and therefore were
trying to prevent stores from selling many albums.” I asked if that made
Patterson think later on, “Let’s go on the Net so we don’t have those
bozos to worry about.” “Yeah, yeah. That actually had a big part in it.”

From the start, it was clear that Patterson’s own music wouldn’t exactly
please the conventional. In high school he played guitar in speed metal
bands, which are “usually a lot faster, a lot more angry sounding” than
heavy metal. When the Ugly Mugs found each other at William Hart High,
Patterson rejoiced in his friends’ weirdness. The style in this case was
Dada, a form of random art.

“Who cared if anyone liked listening to it,” Patterson said. “We just
wanted to play it. We were using mainly guitar and keyboards and bass.
However, we wouldn’t always play them in the normal standard ways. Like,
we’d use guitar for percussion or something, and we had also used a
vacuum cleaner and things like that. A lot of times we just recorded
sounds of things that were just laying around.” Their big gig was at an
interpretative dancing class at a community college where teacher and
students loved Dada-style mime.

The Ugly Mugs was a life, not just a band. Except for an Egyptian
guitarist, whose hair stubbornly kept turning into an Afro when he let
it grow, all the Mugs sported long locks. In a dark, ratty,
poster-ridden room, they would talk politics and philosophy, standard
teenage fashion.

Lord ended up at the University of California at Santa Cruz, and
Patterson himself went on to the University of California at Berkeley,
where he studied computers, his fallback field. He had made music on
them in high school, and, in fact, at Berkeley. “I started changing my
major to be a combination of music and computers. Two years into it I
really got frustrated with the high pressure and decided to transfer to
U.C. Santa Cruz. It’s right on the beach, a laid-back community.
Everyone drives, like, five miles under the speed limit.” Beyond that,
members of the Ugly Mugs had moved there, and in Patterson’s opinion,
the school itself was “really great.”

David Huffman taught there. In a certain niche of computerdom, Huffman
was famous as the creator of Huffman coding, a compression routine that
software products such as Stacker use to double the space available on
hard drives. Music isn’t exactly a low-bandwidth use of the Net.
Compression routines of one kind or another are de rigueur for the
transmission of high-quality sound—not just because of the space that
the material requires, but also because big files take longer to
transmit.

At the time Patterson moved to Santa Cruz, he wasn’t using Hoffman
compression on the Net or posting CD-quality sound from hundreds of
musicians through an IUMA-style operation. But like other techies, he
was posting files in the synthesized MIDI format. “The stuff I put up
there, it sounded like a bad Casio keyboard playing our songs. It really
wasn’t very representative at all. I’d just sit there at my computer,
compose ’em on the computer, and upload ’em on the Net. I posted them to
a couple of news groups, like alt.binaries.sound and things like that
and basically got no response at all.”

Jeff Patterson was reading the supermodel newsgroup when he saw a
posting from Rob Lord in favor of Kate Moss, the model that so many of
the regulars considered too bony. Patterson replied. “We were both huge
Kate Moss fans.” Lord sent him some e-mail talking about how Kate Moss
should be the “queen of supermodels.” People on the Net have a custom of
leaving “signatures” at the bottom of messages—places where they may
post their address or phone number, or an I-don’t-speak-for-IBM
disclaimer, or quote somebody to support them or deride them—and
Patterson took quick notice of Lord’s “.sig.” It alluded to “MPEG Audio
Compression, 16 to 1 CD Quality.”

“And,” Patterson recalled, “I was like, ‘Wow, what’s that?’ So I
e-mailed him back talking about getting together some Moss pictures, and
in passing I asked him about MPEG compression.” MPEG stood for Motion
Picture Expert Group—engineers who set standards for audio and video
compression. Growing curious, Patterson downloaded software so he could
play MPEG through his sound card. The results delighted him, and he
spread the news to the other Ugly Mugs. Hey, guys, Patterson said in
effect, what if we put our music on the Internet? “They thought it was a
pretty good idea. So we decided to chip in together and go ahead and buy
the software that we needed to compress MPEG files, because you could
get that player for free, but the compressor cost $100. Rob came over to
my house, and I told him we were putting our band on the Net, and he was
all excited about the whole idea of creating this archive of bands on
the Net.“ But of course! Rave-think could reach cyberspace.

Something was evident here, something obvious to me, but perhaps not to
all the bluenoses and prudish, power-fixated bureaucrats. Patterson and
Lord were proving the old wisdom that hormones could drive technology on
the Net, or at least the applied variety.

The wizardry of MPEG would be useless if people didn’t use it. And it
took a meeting of Patterson and Lord in the supermodel group—not one
devoted to Bible study, or to paeans to Bill Clinton or Al Gore, or to
the mandarins of Singapore—for IUMA to give MPEG one of its biggest
boosts on the Net. Why, horror of horrors, Patterson and Lord just may
have wanted to scan and swap _copyrighted_ photos of Kate Moss. One way
or another MPEG would become important on the Net, but thanks to people
like these two, it was happening far faster than it would have
otherwise. Technology was at odds with the vested interests of record
companies, and they knew it.

At around the same time IUMA was getting under way in fall 1993,
lobbyists for the companies and performing artists were fighting for
laws that could lead to onerous pay-per-listen schemes—while publishers
were trying to lay the basis for pay-per-read. Indeed, business people
and creators should receive fair compensation, especially the creators;
but in the zeal to protect major political contributors from the
entertainment industry, bureaucrats and lawyers could imperil technology
in the most lethal of ways. Bruce Lehman, Bill Clinton’s intellectual
property czar, would prove it later with a stunningly oppressive
proposal called the Green Paper, a technophobic lawyer’s wetdream, a
techie’s nightmare.

The first song the Ugly Mugs put on the Net was called ”_Arbeit Macht
Frei_”—German for “Work will make you free.” A punky carnival song, it
sparked an instant debate on free speech.

Asked about the title, Patterson told me, “It was kind of born out of
our frustration of, ‘In order to have the money to do everything that we
want to do, we have to work, but if we work, we can’t do anything we
want to do.’ So it was kind of like commenting on people’s attitude of,
‘If you work you’ll be able to do what you want to do,’ when actually
you won’t be able to do what you want to, because you’ll be working.
Actually it wasn’t a smart song title. It was a phrase that was over the
gate on the way to the Auschwitz concentration camp in Poland.
Unfortunately, people took it to be this Nazi song, which is actually
completely the opposite of what we meant.

“We got responses from people who flamed me because they thought it was
extremely cruel to be using this as a name for a song and taking it all
lighthearted when it actually meant something serious to a lot of
people. Whenever anyone actually wrote to me, I usually sent them back
the lyrics and explained our stance, why it was called that. It
definitely created enough of a stir among the few people who heard it.
You wonder if a label would ever take a chance with something like
that.”

On the Net, however, “_Arbeit Macht Frei_” would find its audience. A
man from Turkey asked for a full demo tape—unavailable—and more songs.
Other Netfolks wrote in from Texas, Florida, and elsewhere in the
States, some of whom said more or less: “You know, wow, I’m a Zappa fan
and I can hear the influence. It’s pretty cool.” The Net, in character,
was blurring distinctions between artists and fans and helping the two
groups mix. “We realized we had something,” Patterson told me. “Like,
‘Jeez, we got these responses to a band that had never played anywhere
and didn’t have a tape out.’ So we started grabbing a couple of our
friends’ bands—like my roommate’s. And we put Rob’s roommate’s band up
there, and we just kind of kept grabbing bands to put up. And slowly
everyone was getting one or two responses to what they had posted. And
we needed a place to actually keep all this music. There were like four
bands maybe at that time.”

Patterson, however, quickly filled up all the disk space available to
him at his commercial Internet provider, Netcom; so he and Lord
contacted their university and asked if they could store the music
there. “Well, it turned out that the guy who was in charge of running
the FTP site was a musician—he was in four bands—and he said, ‘Sure, go
for it.’ And we put his four bands up there.”

The technology would have seemed infuriatingly hard to the world at
large. You couldn’t just hook into the World Wide Web, point and click
your way to the IUMA archives, and choose the song you wanted; no, you
had to do FTP, short for File Transfer Protocol, threading your way
through the big hard drives at Santa Cruz, until you reached the
subdirectory with the music. And then, with most software, you had to
type out the file names. Patterson and Lord didn’t even start out with
postings on Gopher (which, to be grossly simplistic, is a more primitive
version of the Web).

Even back then, however, the two were thinking about the Net equivalent
of album covers or of the J cards that record companies used to tout
cassettes. In other words they didn’t just post files of sound alone.
They also pondered the use of files with pictures that music fans could
download.

“At this point,” Patterson said, “it was still just a fun project. We
didn’t think about making it a money-making venture at that point. We
were just like, you know, ‘Let’s put bands up and see what we can do to
mess with the record industry.’ We had this attitude like, ‘We’ll cut
out waste in the industry.’ At that time there was, like, no press about
us, so we weren’t really vocal, but we had those attitudes. We were kind
of like naive and rebellious.”

Then an event happened that was almost as significant to IUMA as was the
discovery of MPEG. Lord discovered the World Wide Web. “None of us,”
Patterson recalled, “had any clue what it was. I think it was in
December of ’93 that we got a hold of a copy of Mosaic.” They tried it
out in a faculty lounge at U.C. Santa Cruz. “There wasn’t really much
content on the Web at all. It was pretty much, like, weather satellites.
We realized from that point on that we could really do something with
taking the music and the pictures and using the World Wide Web as the
way to present everything. People would be able to look at the album
cover, read the text, see ‘play’ buttons. You know, press the play
button, hear the music, and all that sort of thing.

“So,” Patterson said, “we called up the guy we knew from maintaining the
FTP archives at U.C. Santa Cruz, and asked him what he knew about the
World Wide Web.” Overnight he learned how to set IUMA up on the Web. His
name was Jon Luini, and he would become a partner in IUMA, the co-czars’
“Kaiser.”

Meanwhile IUMA’s popularity kept growing, and soon the archives landed
on SunSite UNC, a big digital library sponsored by Sun Micro Systems at
the University of North Carolina at Chapel Hill. IUMA would even make it
to servers in Europe, so that people there could enjoy the music without
tying up the trans-Atlantic connections. Other big companies, such as
Silicon Graphics, took an interest in IUMA and donated computers and
other gear.

But how were Patterson and Lord—and their musicians—going to make money
off the Internet, where “free” was a religion and where commercial audio
might be pirated? I loved the many legitimately free pleasures of the
Net. It was truly for sharing. IUMA, of course, was offering lots of
music at no charge. Via the World Wide Web, I myself was giving away a
book chapter I’d written for a forthcoming information science
collection; and I hoped that at least some material from _NetWorld!_
would be retrievable without any money changing hands. But what to do
about the darker side of “free?”

Sympathetic to the cash-short but clearly a realist, Lord told how
casually kids copied computer games for each other. “There’s a complete
underground going on,” he said, and he told how young hackers had
secretly turned the IUMA archives into a site for stolen software. The
mischief was hard to spot just by doing the usual check of the storage
area.

“We deleted their stuff,” Lord recalled, “and left a note saying, ‘Leave
us alone, you Rug Rats,’ because it was clear there were 13-year-olds
doing it. Some of the biggest pirates in the world are younger than 15.”

His words rang true. Adolescents in the States were no match for the
best pros abroad, but the teenaged pirates could still be awesomely well
organized. One group of teens might crack the software. Another group
might craft a slick screen telling who had defeated the protection. Lord
told of a 13-year-old making $24,000 a year writing and selling
shareware; and although the business was legitimate, this example showed
the energy and brains out there among the young—in other words, the
difficulty of fighting rip-offs.

Lord and Patterson were thinking about releasing IUMA offerings with
digital identifiers that would make it easier to track down thieves. And
yet another tack could be to design the music files that you could play
only with the right digital keys. IUMA’s owners were of GenNet; they
were more interested in relying on technology than law to thwart
pirates.

Piracy is one reason why major record companies feel uneasy about the
Internet. Unable to ignore so large a market, they want help in getting
their message across to the strange, young denizens. Warner paid IUMA to
put short samples of music online, along with pictures and information
about the artists. It was similar to what Patterson and Lord were doing
already.

Now, however, like many others, the two were looking ahead to new
business models. Lord had a bunch of possibilities in mind.

One was that people would pay if they liked what they heard, and maybe
even give in advance. Another was that they would receive little
gifts——maybe clay cats?——for making donations.

Patterson, however, offered some models that were more conventional.
Gasp, his comments even sounded like an actual business plan.

First, he said, he and Lord would take orders for CDs and tapes online
for companies such as Tower Records. Then IUMA would go the next step.
It would sell files of music electronically. Fans would be able to use
Web browsers like Netscape to encrypt credit card numbers so hackers
couldn’t intercept them. Eventually IUMA would sell music for instant
listening without customers first having to transfer it to their hard
disks. “There could be some kind of royalty treatment,” Patterson said.
“You might pay two cents every time you listened to a song. Or you could
just buy an album.” Some good possibilities existed here as long as no
one gouged. If people could hear music with just a tiny investment up
front, that might benefit new performers.

More immediately, IUMA was helping fledgling musicians and others by way
of an informal support network. Sue Few, a Santa Cruz woman who’d
formerly worked for record companies, went online with a newsletter
called _Sound Check_ and offered a stream of tips on subjects such as
copyright law, musicians’ unions, royalties, and lining up bookings.
“Booking people aren’t so bad, are they?” she wrote. “If they enjoy your
tape and feel you’ll fit well with their customers, you’ll get
booked—simple as that. So they don’t return your telephone calls—keep
calling until you talk to a live person and still keep calling until you
get an answer and a date from them.”

IUMA itself was a calling card of sorts. Record companies and clubs
could cruise the archives looking for bands to sign up.

Most important of all, however, IUMA helped potential fans and musicians
get together. At the time I toured the IUMA area you could check out
offerings by “Last 15 Bands” just uploaded to the archives, by artist,
by label, by location, and by song title. Or you could click on a
database with a number of options. I myself wanted to know more about
Scott Brookman, who had written “When I Die You Can’t Have My Organs,”
and who, as a result of IUMA, had been on National Public Radio.

A digitized photo showed him to be a bearded man with glasses. Something
white was against his face, though I couldn’t quite discern the shape. I
hoped it wasn’t a stray from an anatomy lab.

Messages on the screen said IUMA would let Netfolks listen to Brookman’s
“Organs” in stereo or mono. I clicked on the latter option and watched
the bottom of my screen as it showed the number of bytes passing over
the wires from a computer in California to my 486DX-class machine.
Within 45 seconds I’d received a 119K file. In size it was equivalent to
maybe 60 double-spaced, typewritten pages even though this was music not
text.

“When I die,” the lyrics wafted out of my stereo hooked to the 486, “you
can’t have my organs, though you think that you will need them ...” If
I’d had the right software on my machine, I could have heard several
minutes’ worth. The song was good even if, with my primitive sound
software, it wasn’t even AM in audio quality. My rather untrained ears
picked up a Loudon Wainwright-ish edge to the music. I made a mental
note to myself. When I was off my book deadline, I’d do what I should
have done in the first place and install the MPEG software whose
existence had helped make IUMA possible. I had heard only a little cut
in another format With MPEG I could have enjoyed three minutes’ worth,
and in better fidelity.

In the IUMA area Brookman said, “Organs” was “from my latest cassette
release, ‘They’ll Nickel and Dime You to Death.’” He thought of his
music “as a bizarre mix of stylistic parody, satire, self-referential,
and meta-songs, full of clever guitar riffs and daring vocal harmonies.
I write about personal heroes, local history, teenage memories, bits of
folklore, and sometimes I make fun of rock music (lovingly, of course).
Usually the result is intentionally funny ...”

Brookman’s inevitable pitch for money was reasonable enough. “I hope you
enjoy the song, and I really think you should get yourself a copy of
‘They’ll Nickel and Dime You to Death.’ Send a check for five bucks (no
charge cards) made payable to Loser Records. That’s a full 60 minutes of
awesome music for only $5. Where else, other than a used record store,
can you find that kind of entertainment bargain? Here’s our address:
Loser Records, P.O. Box 14719, Richmond, Virginia 23221.” Hey, I’d
already enjoyed a bargain, his delightful little fan area. I would
remember the name Brookman.

People could leave feedback and I brought up some. “My colleagues and I
agree—what a scream!!” read a note from Virginia, where Brookman lived.
“I think we’re going to track down your CD. Congrats on a nifty tune!
It’s good to hear a local band ‘make it big.’” An Australian wrote in:
“Heheheheh. Nice sense of humour.” None other than Jon Luini, Raiser of
IUMA, said of “Organs”: “I cannot get this song out of my head! The
sincerity around this song is a great combination with the odd nature of
the lyrics, especially when combined with the folk feel of the music. It
makes me feel like it should be included whenever people first get their
driver’s license.”

Brookman’s electronic mail address was online, of course, together with
those of listeners who had offered feedback. Anyone wanting to start a
fan list focused on him would already have some names and e-mail
addresses handy.

This was what the Net was so good for—not displaying Canteresque spam on
behalf of Green Cards or pitches from CBS to join its fan club.

Small business actually enjoyed an advantage here. To CBS, fan mail must
have been a nice a way of gauging the market. But the Brookmans of this
world could go far beyond that and establish good rapport with fans, one
by one—something for which the people at the CBS site would never have
had time, given its volume. Small worked in other ways for Brookman. He
or Loser Records (were they the same?) could do a short run of CDs and
spread the news with minimum investment. Pressing a thousand CDs costs
less than $2,000 nowadays. Combine that with the Net, and the music
world just might be a little kinder to a young performer than it was in
the days when Lord and Patterson were toiling away in the record stores
back in Valencia.

Granted, a place in the IUMA archives was hardly a guarantee of success.
A musician with the band Black Watch told me that she and her colleagues
normally heard only from a fan or so a week. IUMA would _not_ make a
band instantly rich. On the other hand, she loved the feedback and
encouragement that arrived from all over the world; and, we both
thought, wasn’t that important, too—not just the money? The music was
finding its way to those who loved it. Besides, in the end, all the
small fry might add up. Lord said that instead of one Madonna there
might be fifty—“Maybe it will no longer make sense to have even
one.”[3.2] Perhaps, I hoped, the money instead would reach the Black
Watches.

Once Lord had predicted that in several years IUMA might be “a one- or
two-digit percentage of the $9 billion music industry.”[3.3] I didn’t
know what would happen. Major record companies would surely be doing
plenty on their own. And when I talked to Lord in April 1995, IUMA’s
annual revenues were still in the low six figures. But that could
change, quickly. No matter what happened, IUMA was brilliant for a
niched world in which millions were rebelling against the
any-color-if-it’s-black mindset.

We want just the right friends and spouse; the right home; the right
coffee; the right newsgroups, now that they existed for all; and, yes,
just the right music.

                  *       *       *       *       *

The same nichization is happening in the world of publishing—the
Internet is home to hundreds if not thousands of electronic
publications. So what’s a hometown paper to do? Just how is _Time_
magazine responding? And in such strange times—normal times, actually,
once they’ve been around long enough—what becomes of books, especially
when you consider the digital piracy issue. In the next chapter I’ll lay
out the problems and even suggest a few solutions.




                                CHAPTER
                                  FOUR

    Pulped Wood versus
    Electrons: Can the
    Print World Learn to
    Love the Net?


I ran across A. C. Snow on the Internet the other day, and old memories
poured forth.[4.1] A.C. is as low tech as they come. He writes a Tar
Heelish column with jokes and stories about church picnics and football
and beach trips, and yet there he was online with the folksy prose that
I remembered from eons ago. The _Raleigh Times_ is gone now. A.C. works
instead for the bigger _News & Observer_, a sister newspaper that
thudded against my dormitory door when I was in college. Weekday
circulation is around 150,000 nowadays, and many state legislators wake
up each morning to the _N & O_—it just might be the most powerful paper
in North Carolina.

Millions of people on the Net, however, would question the need for the
three-story tan brick building, the fleet of delivery trucks, and the
recent decision to invest $36 million in color presses.

You can’t update the ink on pulped trees the way you can move around
dots on a computer screen. “Aren’t newspapers obsolete?” scads of
techies are asking. Besides, the Raleigh-Durham-Chapel Hill area has
changed. Thousands of locals swap e-mail addresses at cocktail parties,
while many schoolchildren grow up reading off computer screens as well
as from books. IBM and other Fortune 500 companies are in Research
Triangle Park outside town.

Still, like the Raleigh area, the _N & O_ has evolved. In a nearby
building, a small crew is putting out electronic newspapers on the
Internet and on a bulletin board system. This isn’t just a
pulp-and-ink-era newspaper company. It’s also an Internet provider.
Aided by two phone companies, the _N & O_ gives out free Internet
service to teachers and students to find out what the latter would like
online in the future. It’s offered Netfolks a colorful, multimedia tour
of the state. Tens of thousands drop by the _N & O_ area each week. “The
Internet is like the real world—unorganized, unruly, and filled with
more happenings than any one person can possibly track,” says Frank
Daniels III, the paper’s executive editor. “It’s growing at a fantastic
speed, and its citizens are literate. An opportunity for editors!”[4.2]

Not everyone on the print side feels as he does. When a _Washington
Post_ writer did a gossipy little item on Cliff Stoll’s net.exposé, the
journalist said book editors were looking forward to reviewing _Silicon
Snake Oil_ as “confirmation of what they hoped was true all along.”[4.3]
That may or may not have been a joke. Whatever the case, a war is going
on between pulped wood and electrons. Can commercial publications, from
newspapers to book publishers, learn to love the Internet, and what does
this mean to us readers?

“There is no doubt in my mind that the Net will force a transformation
of newspapers,” says Peter Lewis, a cyberspace writer for the _New York
Times_, “but demise? That’s what they said about radio and television as
well.”[4.4] Just the same, a headline in _Wired_ magazine said online
newspapers “still suck.” Many newspapers are too enamored with the
traditional models where editors and writers inflict whatever they want
on the unsuspecting public. They don’t give their readers enough of a
chance to speak back online or communicate with each other. Still, the
best electronic publications can indeed be two way. And more and more of
them will be packaged for the medium. You’ll be able to read summaries
of stories, for example, and then summon up longer versions with a click
of the mouse.

Even ads may improve. “Think of the typical print tire ad,” says Teresa
Martin, an online expert with the Knight-Ridder newspaper chain.
“_Yawn._ But what if touching each tire bought up detailed specs about
it, or the sizes in which the store currently has it in stock—or even
some really cool car careening around a racetrack with the voice-over
‘speed rated?’ The ad can be like a window to a store, enticing the
reader in to look for information.”

I know—computers are too hard for many technophobes to learn, too big to
use in bed, and often too blurry or flickery to read off of; and
batteries are forever eager for their next charge. But life will get
better. It will happen faster if governments worry less about smartening
up TV sets and more about smartening up schoolchildren with programs
that drive down the cost of book-friendly computers. Much, however, is
already going on. Xerox, for example, has experimented with a computer
screen whose output is as sharp as printing on paper. It’s a power hog,
but less hungry screens are coming. Writing in _Digital Media_, Martin
says the right hardware could be a mere six years away.[4.5] I myself
think—based on my monitoring of technical publications—that her estimate
is conservative.

Besides, even now, electronic texts can at least complement the paper
kind. For example, they can increase the variety of newspapers, books,
and magazines available. After U.S. Senator Jesse Helms joked that Bill
Clinton would need a bodyguard to protect him from angry service people
who resented his military policies, I did not rely just on the
_Washington Post_ for details. I called up the story directly from the
_News & Observer_ hundreds of miles away. What’s more, it’s easy to
wander from one electronic publication to others when you are after
facts on the same topic, or to search back issues of newspapers and
magazines. Even novelists are discovering the possibilities of the new
media. Readers can choose their own endings or pass on suggestions to
the authors of works in progress.

Adventurous media people are trying to adapt to this online world as
gracefully as they can, and the Internet is oh so enticing to many. The
cost of the technology has fallen to the point where a bare-bones
newspaper can go on the World Wide Web by investing as little as
$5,000-$10,000 up front. Publishers needn’t divvy up revenue with a
commercial online service, such as America Online or CompuServe.

Compared to pulped wood, the Net looks better and better—the price of
paper shot up some 30 percent between the fall of 1994 and the spring of
1995. Environmental regulators are forcing the pulp mills to quit
sullying the air and the water, and new mills can cost half a billion
dollars each to build. “Like the rest of us,” writes Jonathan Seybold,
publisher of _Digital Media_, “the paper company executives read all of
the press stuff about the Information Highway, the rise of online
services, and the decline of paper-based publishing.” And he says they
are now asking, “Why should we invest in a new paper mill?” The result?
Newsprint shortages and higher prices. “The fear,” Seybold says,
“creates its own reality.”[4.6]

More than 100 newspapers either are on the Internet or are planning to
be there. The _New York Times_, for example, has used the World Wide Web
to transmit a fax edition condensed from the normal paper. A full-grown
_Times_ may be on the Net now. The _San Jose Mercury News_ in California
not only is online, it offers a service called News Hound. For just $10
a month, the Hound will automatically scan a massive database from
Knight-Ridder papers and additional dailies, then e-mail you the latest
articles on the cover girls of _Sports Illustrated_, on Afghanistan, on
the Chicago Bears, on Bill Clinton, or on any other topic that quickens
your pulse or makes you reach for your Valium. From the _Halifax Daily
News_ to Poland’s _Gazeta Wyborcza_, newspapers are trying the Net. Even
a strike paper, published by reporters of the San Francisco _Examiner_
and _Chronicle_, made it into cyberspace.

Some Netfolks preferred the strike daily to the electronic spin-offs of
the regular ones, and I wasn’t surprised. What applies to business
applies to newspapers: The Net is a great equalizer in some ways; a
small newspaper can reach as far-flung a readership as an international
daily. In fact, the first paper on the World Wide Web just might have
been the _Palo Alto Weekly_ from Silicon Valley. South Africa’s _Mail &
Guardian_, a 30,000-circulation weekly, finds the Internet a much
cheaper way to reach people overseas than air-mail. Devoted to Russian
news, the _St. Petersburg Press_ uses the Internet to serve an
English-speaking audience throughout the world. The _London Telegraph_
has shown up on the Net with some striking graphics. No longer is the
Internet just for little magazines published by techies and smart young
English majors.

Time Warner has put _Time_, _People_, _Entertainment Weekly_, and a
shelf full of other magazines in a colorful, well-done area of the World
Wide Web. Readers can praise and flame the editors and each other.
Hearst magazines have their own area. _PC Magazine_, one of the giants
of the Ziff-Davis chain, enraged many Netfolks with clueless articles
suggesting a rather thorough ignorance of the Internet and its reasons
for existence. But guess what. Now Ziff-Davis has a wonderful Web area
with generous samples from its magazines, including _PC_. The German
newsmagazine _Der Spiegel_ is on the World Wide Web, too, complete with
some news in English; from Japan, specialized publications serve Net
audiences ranging from gays to office workers.

I learned of the most dramatic use of cyberspace by a magazine just as I
was finishing this book. _Omni_, the popular science publication, said
it would forsake monthly paper editions in favor of a version on America
Online, augmented by just four print editions, one each quarter. It
expected to save some $4 million a year. The newsletter _Interactive
Week Publishing Alert_ raised some valid questions—copies of back
articles from _Omni_ were too hard to locate—but even if the grand
experiment failed, the model was out there. A major publication was more
or less forsaking pulped wood in favor of computer networks.

Book publishers are catching up with newspapers and magazines. Time
Warner, Random House, Macmillan, and McGraw-Hill use the Internet for
promotion, and they will distribute more and more of their books this
way. Free classics like _A Tale of Two Cities_ have been a staple of the
Net for years, thanks to voluntary efforts such as Project Gutenberg.
And now you can pay a few dollars to download a short story by Stephen
King or works by many others.

Meanwhile, however, some old-fogey publishers view the Internet as an
unfathomable virus transmitted via cable. That’s especially true of the
book business. People in it fear a massive bootlegging of their wares.
Using the Net, you can even pirate paper books; there is no technical
reason why machines cannot scan the latest from Philip Roth or Tom
Clancy, convert their novels to bits and bytes, and zap them to your
friends in Juneau. Software-based copy protection could help safeguard
electronic books. But I myself think there are other solutions as
well—for example, a national library fund to make free or low-cost books
practical and reduce the incentive for bootlegging.

Paper publishers also complain that if electronic books are cheaper to
create and distribute, manuscripts will receive less editing. With a
good library system in effect, however, a way would exist to highlight
works of merit—marketers would enjoy less clout and we’d see fewer
best-sellers on astrology and more on history. And without the
distribution costs, more money could go to writers and editors.

Other obstacles also exist in the minds of publishers eyeing the
Internet. Some worry about finding a market for text offered through a
global network. And certain people in the book industry also dread the
competition from the many gigabytes of free material that the Internet
offers. Didn’t Samuel Johnson know best?—No one but a blockhead ever
wrote except for money. If nothing else, many word people are captives
of their senses. They hate reading off computer screens; they want to
hear a newspaper thunk against their doors, hold Section A in their
hands, hear it rattle, sniff the ink.

Going in the other direction, many people on the Internet love to bash
the print world as benighted and even a little worthless. Who needs
publishers when you can post your own books and little magazines for the
world to read on the Net? That’s simplistic in many cases; I’ve got a
little more faith in the editors at Knopf or Viking than I do in the
proofreading gang from the Department of Chemistry or Joe’s Literary
Bar.

People on the Net, however, are right to criticize the print media’s
ignorance of electronic publishing and computer networks. If nothing
else, many traditional publishers fail to grasp the potential here.
Looking at the old, underpowered machines that clutter their offices,
they may believe that computers won’t progress from there. An
intelligent staffer with a publishers group—someone I respected on other
matters—didn’t understand the promise of computers for reading e-books.
I shared this story with Robin Peek of Simmons College, who coedited a
book on electronic publishing for the American Society for Information
Science and the M.I.T. Press. She told me that many book publishers just
hoped that computers wouldn’t improve until the publishers died or
retired. Computers keep stubbornly getting better, though; blurry
screens and fragile hard disks won’t always be the order of day.

More amazingly, a popular magazine misinformed some of us Netfolks that
we were “netgods.” Didn’t our Internet addresses end with a prestigious
“.net” rather than “.com” (the designation for a commercial site) or
“.edu” (for a school site)? Strange. Anyone can pay $14 a month to
ClarkNet or many other services and automatically get an address like
rothman@clark.net. So much for my godliness.

Zeuslike, however, I’ll hurl thunderbolts at HarperCollins and
Doubleday. The former published the book that the immigration lawyers in
Arizona used to justify the off-topic ads that they had inflicted on
thousands of newsgroups. The Canter and Siegel guide was in the same
class as astrology books. It talked about spending just $.0333 per
thousand users per month to reach 30 million people on the Net. Most of
the people, however, can only use e-mail and aren’t on Usenet or the
Web. Doubleday erred in other ways. It let Cliff Stoll smear cyberspace
as “devoid of warmth and human kindness.” Devoid? A rather
all-encompassing word. In both cases the paper publishers were entering
an unknown world.

To give another example, a _New Yorker_ article lamented the destruction
of library catalogues without really telling how electronic libraries
could do the job better. The article went on about the handwritten
annotations on the cards, and I could see the point here. Couldn’t a
card for a Civil War book include an informal recommendation for a book
on Antietam or Gettysburg? Must all cross-references be official? So I
could appreciate writer Nicholson Baker’s worry about the fate of those
beautiful wooden cabinets. What he played down, however, is that
technology can let electronic librarians create quick paths from one
work to another.[4.7]

Far from being exotic nowadays, this technology is the essence of the
World Wide Web. So if you looked up a general item on the Civil War, you
might see some annotated references to an item on Antietam, and go there
instantly with a click of the mouse.

Just as wrongly, an article in the _Atlantic Monthly_ of September 1994
said future electronic books could perish because they used many disk
formats. “The End of the Book?” asked the headline over T. J. Max’s
doomsaying. But CD-ROMs and books on floppy disk are just transitions.
Unless legislators interfere in the most ham-handed of ways, computer
networks should be the natural homes for electronic books. They could
reach us more cheaply, and in greater varieties, without the bottleneck
of physical bookstores. So disk standards should be just plain
irrelevant in the end. The true raison d’etre for the Internet is its
ability to let many kinds of machines share information without the
least worry about floppies or magnetic tape. Most of the time I don’t
know if my no-name IBM clone is talking to a Mac or a $5-million
mainframe. Besides, we mustn’t preserve books just physically; in a
videocentric era we also need to help them survive in the minds of
readers, particularly those outside the elite. We should spread books
far and wide, then, and make the technology as friendly to words as
possible.

But tell that to Max. In his eagerness to put down electronic text, Max
depicted the _print_ version of _Wired_ magazine as hypocritical. He
wrote:

_Although_ Wired _communicates extensively by e-mail with its readers,
conducts forums, and makes back issues available on-line, its
much-repeated goal of creating a magazine—currently called_
HotWired—_that is especially designed to exist electronically remains
fuzzy. For the moment this is no open democracy, and_ Wired _is no
computer screen—its bright graphics would make a fashion magazine
envious_. Wired _celebrates what doesn’t yet exist by exploiting a
format that does: it’s as if a scribe copied out a manuscript extolling
the beauty that would one day be print_.

Strange. Just what’s so odd about using old technology to spread word of
alternatives, especially the dazzling e-magazines that already enliven
the Web? When Nicholas Negroponte published _Being Digital_ (New York:
Knopf, 1995), a bestselling collection of his lively _Wired_ essays,
some Generation Xers bought it not for themselves but for their
parents—which was exactly what Negroponte wanted.

Max is especially off target about _HotWired_. Today, just months after
he wrote of the publishers’ “fuzzy” goal, the magazine is one of the
most successful on the Net with far more than 100,000 readers. It makes
massive use of hyperlinks—the technology I described by way of the Civil
War example. Within discussion areas, readers can create links from
their posts to text, pictures, and sound elsewhere in the World Wide
Web, including their own electronic pages—they needn’t confine
themselves to tiny letters to the editor. Simply put, _HotWired_ both
praises and exemplifies the new medium.

I couldn’t care less, moreover, if this electronic magazine runs long
articles that have come out in print or could have—just so _HotWired_
also gives me new material. Not everyone on the Internet reads the
printed _Wired_. One of joys of the Net, moreover, is the ability to
offer greater levels of detail for those wanting it. What a grouch Max
is. He might as well be a monk lecturing Gutenberg about the glories of
calligraphy.

Even _PC Magazine_, one of my favorites, at times can be all wet about
the Internet and related topics. A columnist suggested that most people
on the Net be forced to pay for each letter sent out; supposedly,
Netfolks were too quick to e-mail each other. Excuse me. Such an
approach could kill off many of the mailing lists through which
academics and nonacademics swap ideas and research notes en masse. A
very small fee based on actual costs and Net congestion? Maybe. But not
one designed to minimize use. To the columnist, however, the Net’s role
as a petri dish may count less than its promise as a corporate mailman.
He misses a major point. The Internet is one of the planet’s cheapest
ways to transmit knowledge, including the kind that might cure cancer or
give us a 150-mpg automobile. While commerce on the Net is laudable, we
need those mailing lists as well—and not just for professors but public
schools, libraries, charities, psychological support groups, and
activists of all ideologies, to name just a few of the better examples.
The economics of the Net will make this possible, especially as
bandwidths increase to accommodate greater use of audio and video—text
just won’t cost that much. Alas, the columnist in this instance failed
to understand the Internet and its possibilities.

I myself won’t claim omniscience about the Net. Once I saw a message on
a mailing list from someone pushing for a huge National Knowledge
Foundation to benefit educators, librarians, journalists, and
investigators. The post mentioned international topics, among others,
and flares went off in my head. I posted some sharply critical,
journalistic questions, wondering if the post had come from a CIA type.
Some people on the list cheered me on while I pressed for public
answers. It turned out that the post _was_ from a former Company man,
and as I persisted in querying Robert David Steele about his funding and
motives, he sent me a colorfully worded note that might have made a
Paris Island drill instructor envious. I quoted his e-mail, as I would
have done if writing this up for a magazine. What a way to justify my
fears of the intelligence establishment playing too powerful a role in
determining the content of material online. I remembered the valuable
exposés that the press had done of the CIA years ago; we need to
separate U.S. journalists from spies, lest impartiality of the news
media suffer. This debate I would win.

But I didn’t. In fact, I suffered a major debacle; flame after flame
from bystanders assailed _me_. Even though I told Robert Steele I wanted
public answers, people felt that I had violated the traditional
prohibition against quoting private posts in public, at least with names
attached. Some of the bluntest Anglo-Saxonisms came from luminaries on
the Internet. People wanted perfect freedom to speak their minds in
messages deemed private, just as professors and students in class would
want to be free to say outrageous things without ending up on the front
pages of the local paper. I, on the other hand, had applied journalistic
expectations to the Net. A reporter might end up with a better story if
a celebrity exploded during an interview and this fact came out in
print. But on the Internet, the freedom to be outrageous in private
mattered more than the freedom to quote, even with advanced warning.
Yes, I had questions about this custom. What if people took advantage of
this Netiquette to engage in sexual or racial abuse, or just abuse,
period? Should rules really be hard and fast? Just the same, in Net
terms, I was the loser here because I wore my Writer Hat at the wrong
time.

Luckily the story ended happily. Robert Steele and I, while disagreeing,
made our peace. I went to one of his conferences and shook his hand.
Later I happily discovered that he shared my hatred of the Clipper chip,
the loathsome White House scheme to make it easier to snoop on citizens’
communications. He was far more openminded than I’d originally expected.
Even without that consideration, however, a feud just didn’t make sense
here. Canter and Siegel may claim you can reach 30 million people in one
swoop, but as I say repeatedly, the Net is a _series_ of communities,
some of them rather small-townish. Within our somewhat overlapping
circles, it would have been mutually harmful for Robert Steele and me to
squander time and reputations on a protracted flame war.

Other kinds of clashes take place between Internet culture and that of
traditional media types; in the eyes of many people on the Net, print
people are not the only villains. _Dateline NBC_ ran a story about
children using computer connections to locate recipes for making bombs.
The children, however, could have done the same at bookstores or public
libraries. _Dateline_’s episode reminded one Netizen of the time NBC
secretly used a hidden ignition system to show that an automobile could
explode. Just as bizarrely, in print and on the air, some journalists
love stories about the Internet as a playground for child molesters. If
we on the Net were a religious or ethnic group, we could start an
antidefamation league and keep it forever busy.

By Net standards, the media bumble in yet other ways. If you’re a
newspaper or magazine journalist, you may have been reared to neuter
yourself about The News; no opinions online, please. On the Net,
however, many people are suspicious if you do _not_ join the crowd and
speak out. They dislike net-thropologists; that is, media people and
others who study the Net rather than contribute to it. Among some
journalists the standard modus operandi is to post questions for an
article, then vanish without sharing anything with the Netfolks.

Happily, this is changing somewhat. In fact, you can find a few
journalists from the _New York Times_, _Wall Street Journal_,
_Washington Post_, and other major papers speaking up online about
matters dear to them. Recently a reader flamed the _Post_ for its
Internet coverage (“what those idiots at the _Post_ write isn’t worth
minimum wage”). Alluding to software that can screen out messages from
offensive people, reporter John Schwartz punched right back: “It’s bozo
filter time.” He had been using online services for years, and here, it
showed. The old stereotype, in which all members of the major media are
clueless, just doesn’t fly any more. Not too long ago somebody shared a
_New York Times_ article—discussing some other people’s proposal for a
national digital library—with hundreds of a members of a list devoted to
law in cyberspace. He did not ask permission from the _Times_. A pithy
reference to copyright law then emanated from none other than Peter
Lewis, who had written the article and was a regular on the list.

So how are Netfolks treating Lewis nowadays? He e-mailed back an answer
in prose worthy of a discussion group on the Internet itself:

    _It took me a while to get used to being flamed by pencil-dicked
    geeks who hide behind their terminals, saying things I’m sure
    they’d never dream of saying to my face. But now I’ve become
    something of a connoisseur of flamage, and while I regret that
    it is widespread on the Net, I regret more that the quality of
    flaming is almost uniformly weak. I now savor good flames and
    ignore the rest. On the other hand, it took me almost as long to
    get used to having instant feedback, often pointed and critical
    and right-on, to my writing. While there is a danger of a
    “chilling effect” from flamage, perhaps subtly influencing
    reporters to back off a subject in anticipation of a flood of
    “Dear Clueless” letters, I think the overall benefit of instant
    and widespread reader feedback is a Good Thing. Perhaps all
    rookie reporters should be required to write a Net story just to
    let them know that they do not write in a vacuum, whether their
    beat is the Internet or the police station or sports._

Like the police beat, the Internet comes with its set of rules—as my
experience with the CIA alum vividly showed. Some on the Net attach a
statement to every post saying it’s copyrighted. Others just worry that
the wrong set of people may read and quote their more outspoken
messages. Lewis considers list and newsgroup posts to be public: “My
mother once advised me, long before she knew I would be a journalist,
‘Never put anything on paper that you wouldn’t want to see on the front
page of the _New York Times_.’”

Still, Lewis normally catches up with the writers of posts he plans to
quote. “However, the reason has more to do with verification than with
netiquette. In cyberland as well as in the real world, as you know, the
fact that someone’s name and address appear in a letter does not
guarantee the identity of the writer.” Lewis reminded me that “half a
century ago some newspapers forbade reporters from quoting sources
contacted by telephone on the same rationale: How do you really know
that was Mr. Doe on the phone if you didn’t see him? In cyberville, not
only can we not see our sources, but neither can we hear them.” And then
a few sentences later came the electronic signature, “Pete (at least,
you _think_ it’s Pete) Lewis.”[4.8]

Other challenges exist online. When reporters use e-mail for interviews,
they take away the element of surprise—often the surest route to the
best answer. “Also,” says Jordan Green, a Canadian freelancer who relies
heavily on e-mail, “there is no body language or voice intonation in
e-mail. We do have our various symbols to >>>highlight<<< and
_emphasize_ WORDS and feelings :-) but there is far more which cannot be
picked up.”

In the end, however, computer networks will make the press better
informed, not worse. Via Lycos, for example, a searching tool on the
Web, I can track down files written by just the right person to
interview or find background information that someone archived from the
relevant newsgroup. Besides, who says that all interviews are
confrontational? Often e-mail is just right, and I can always use the
telephone to fill in gaps. “I used to ask, ‘What’s your fax number?’ at
the end of a phone interview,” says a magazine writer named Peggy
Noonan.[4.9] “Now I also ask, ‘What’s your e-mail address’ because it’s
often much faster to post a question or send a draft for approval via
e-mail than by another means.” Some journalists might object to showing
drafts to sources. But Noonan clearly sees the networks as a godsend for
other purposes as well.

Another believer is Arik Hesseldahl, a young reporter with the _Idaho
State Journal_ in Pocatello who, like many journalists of his
generation, grew accustomed to the technology in college. “Remember that
flesh-eating bug scare a few months ago?” he said. “I got in touch with
a doctor in England who debunked all the rumors and media hype, which is
what it was—hype. Just today I am looking for an expert on nuclear fuel
reprocessing equipment who is untainted by the Department of Energy and
the rest of the federal nuke bureaucracy. Already I’ve gotten five
suggestions for experts.”

I myself see other advantages for people in the pulped-wood world; via
the Net I don’t just approach editors—I hear from them out of the blue
when they like my postings. Other freelancers have also benefited.
Steven Sander Ross, a professor at Columbia University, uses the Net to
communicate with European magazines that pay better than those in the
States. Just as the Net creates global markets for florists and sellers
of teddy bears, it multiplies opportunities for the best writers. That
is true for newspaper and magazine writers now and will be increasingly
true for authors of books. Mind you, there is a downside, too. The Net
may actually _hurt_ the worst writers as they face more competition,
whether from professionals across the planet or from the free material
that Netfolks share with each other.

Here are three case histories that should be of interest to writers,
editors, publishers, and the rest of the cosmos:

• Case History 1. The _News & Observer_ has used the Internet not only
  to reach the denizens but also to get existing readers and advertisers
  on the Net. In an era when so many greedsters hope to charge
  outrageous fees to consumers for online information, the _N & O_ is
  hoping that ads will pay much or even most of the freight.

• Case History 2. Time Warner, as noted, is putting magazines and book
  excerpts on the Internet, and it’s doing so in ways befitting the
  medium. Many of the same concepts carry over from online newspapers,
  which is why this section and the next will be much shorter than Case
  History 1. In fact, so far, an _N & O_-style business model seems to
  be influencing Time at least somewhat.

• Case History 3. Laura Fillmore runs an online bookstore that not only
  sells books but _gives them away_ on the Internet. She even used the
  Net to promote a pulped-wood book that has sold hundreds of thousands
  of copies. Fillmore’s ideas are significant because she is working
  hard to reconcile publishers’ needs with those of society at large,
  and I commend one of her business models as an alternative to
  pay-per-read gouges. The ultimate answer, in my own opinion, is a
  national digital library and a program to drive down the cost of
  book-friendly hardware. Using this approach—a mix of editorial and
  technical wizardry to add to the value of plain text—good publishers
  would flourish. Readers and writers would come out ahead, too.

Finally, I’ll offer an update on the _N & O_ and other publications on
the Internet. When Frank Daniels described the Net as “unorganized” and
“unruly,” he might also have been talking about certain trends in his
own industry. A surprising twist unfolded in the story of the _N & O_.

Newspapers on the Net:
The Raleigh Experiment

More than two decades ago in a scuffy-floored room at the University of
North Carolina, not that far from the _N & O_, I heard Professor Walter
Spearman expound on the prickly question of uppity letters to the
editor. What if a reader taunted, “You’ll never print this?” The crux of
Walt Spearman’s wisdom was this: _Don’t go for the bait. If you don’t
want to print it, don’t._[4.10] He was teaching me to be, in modern
parlance, a “gatekeeper”—to decide which news and opinions made it into
print and which didn’t. Only so many column inches existed on the
editorial page, and we journalists were to watch over this space as if
it were the Mona Lisa. Without the slightest apology, we should tell the
public what to read, and besides lording over the editorial pages, we
should inflict the same front page stories on everyone. The notion that
each reader could write regularly for other readers, or that he or she
could see wire service stories online, was as sacrilegious as it was
science fiction-like.

By the end of the 1970s, however, at Duke, UNC, and N.C. State, hackers
were paving the way for Usenet, a series of discussion areas on the
Internet and on bulletin board systems that let _everyone_ have a
say—from Nazis to Maoists. Together with talk radio and with other forms
of computer communications, Usenet could help Americans bypass the
gatekeepers. Readers wouldn’t see on their screens an appealing
combination of headlines and Times Roman type. But no blue pencils would
be around to scratch out the heresies of nonjournalists.

Usenet in the end wouldn’t just carry alt.activism or comp.general or
alt.sex; it would also be home to a nice little electronic newspaper
called ClariNet, which in 1995 enjoyed 100,000-plus readers, and which
each day let readers choose from among hundreds of dispatches from
Reuters, the Associated Press, and more specialized services. My friend
Jim Besser covered Washington for a string of Jewish newspapers. He
could dial up ClariNet, other sections of Usenet, and the Internet at
large and see material that might take days and days to wend its way
into the _Washington Post_, assuming it ever got there at all. Usenet in
the end was more of a wire service than a newspaper; that just may have
been its real triumph. Some old print people hated ClariNet, seeing it
as a threat to their gatekeeping. For a while, ClariNet sent out the
columns of Dave Barry, the quirky but popular humorist enjoyed by
thousands of Netheads. Then, however, his syndicate pulled him off the
service. Illegal copies had wafted all over the Internet, and the
bootlegging had surely outraged client newspapers—the main reason; but a
second, minor one may have existed as well—the hostility between the Net
and many members of the print media.

The Internet was partly why Michael Crichton, the author of the novel
_Jurassic Park_, could shrug off newspapers and some other mass media as
“tomorrow’s fossil fuel.” The Cable News Network and radio talk shows
are not the only threats to the hegemony of the old-time gatekeepers. So
are the Internet, CompuServe, America Online, GEnie, Delphi, and, of
course, the more than 50,000 bulletin board systems run by hobbyists and
others. “Newspapers,” wrote the media critic Jon Katz, “have been
foundering for decades, their readers aging, their revenues declining,
their circulations sinking, their sense of mission fragmented in a world
where the fate of presidents is slugged out on MTV, _Donahue_, and
_Larry King Live_.”

I was fascinated, then, to learn that the old _News & Observer_ was on
the Net now. Was the _N & O_ serving readers better? With the above in
mind I spent several weeks talking to the Raleigh people on the phone
and via e-mail, and studying the electronic versions of the newspaper,
both the free samples on the Net and the version for paying customers.

My conclusions were positive, though not entirely. Katz, the author of
the “Still Suck” article in _Wired_, would have disliked some aspects of
the _N & O_’s electronic efforts. _Wired_ had asked, “How can an
industry which regularly pulls Doonesbury strips for being too
controversial possibly hope to survive online?” And, sure enough, if you
were on the Internet by way of the _N & O_’s service in fall 1994, you
couldn’t subscribe to the alt.sex string of newsgroups. Moreover, unlike
the _Time_ areas online, the _N & O_’s BBS had not sprouted hundreds of
messages from free-spirited readers and editors. Truly controversial
postings were rare. And yet the editors were clearly moving away from
the traditional gatekeeping role. Meanwhile, the _N & O_ was enriching
the Internet by way of well-written news stories and features—many
available for free. Flaws aside, this was a fine example of how the
print media could befriend the Net and the young people who favored
computer screens over pulped wood.

Frank Daniels III, the executive editor, tinkered with computers himself
in high school two decades ago, and as early as the late 1980s he was
using Macs to shuffle around stories on the pages of a magazine that his
family owned in Charlotte, North Carolina. Working with a stock analyst,
Daniels created a computerized database of the top fifty companies in
the Charlotte area, and that, in turn, led to a newsletter. So early on,
Daniels saw how high tech could spawn lucrative opportunities. He also
saw the negatives. The owners of the _Los Angeles Times_, Knight-Ridder,
and other organizations were experimenting with Videotext, which allowed
news stories to scroll across television screens.

Such endeavors were brave. They were also premature. Videotext at the
time cost the customers too much, and just as the Prodigy service would
err later on in the same way, the newspapers failed to appreciate the
fondness of many customers for typing to each other. Reading news
stories and shopping from home weren’t enough.

Many U.S. dailies would go on to flounder even on pulped wood. Whether
Americans were watching video-cassettes or hang gliding, millions had
other uses for their time, especially baby boomers. Some 60 percent of
the households in Wake County had once subscribed to the _N & O_; by the
late 1980s, just 40 percent did. Newspapers kissed off much of the
market, jacked up their prices, and began seeing themselves as a way for
advertisers to reach at least the Oldsmobile set if not the BMW set. And
yet, even by those criteria, the _N & O_ was a slacker. Back then, as it
does today, the Raleigh-Durham-Chapel Hill area boasted one of the
highest concentrations of Ph.D.s in the country. Some 40 percent of the
households now own computers, more than 10 percent can go online, and
the average home price is well on the way to equaling that of some major
metropolitan areas. Even five years ago, and long before, high tech was
enriching the Research Triangle.

But would the _N & O_ adapt to this new market, a harbinger for many
other areas in the United States and elsewhere? Frank Daniels saw the
newspaper as a change-proof antique, and he was ready to dump his _N &
O_ stock and sink the money into an online service.

Then Daniels got some journalistic religion at a newspaper seminar, the
secular equivalent of a good Baptist soaking. To hear him tell it, he
suddenly understood that “the relationship between a newspaper and a
community has such a richness and history that communities shouldn’t
lose that.” And he felt that online services could take advantage of
those relationships with readers and advertisers. Today the _N & O_ goes
by this philosophy, not entirely but to a great extent. Readers can
e-mail many of their favorite writers, while long-time advertisers can
buy _X_ number of column inches in the paper editions and receive
exposure in the electronic editions.

Something else, however, may have bound Frank Daniels to his paper as
well—old family stories and the memories they stirred. The first Daniels
landed in North Carolina several hundred years ago, and the family
reunions continue to this day. Frank III’s great-grandfather, Josephus
Daniels, purchased the _N & O_ at a bankruptcy auction in 1894. He
carried on as one of the state’s more colorful and outspoken publishers,
with a strong populist streak, and took time off in Washington to serve
as secretary of the Navy under Woodrow Wilson. I ran across Josephus on
the Internet, just as serendipitously as I had found A. C. Snow. Through
the American Memory Project at the Library of Congress, I could _hear_
Josephus honor two naval heroes with a speech called “There Is No Rank
in Sacrifice.” I passed on word of my discovery to Bruce Siceloff, an
online editor, and he played another Daniels’ speech for the clan while
showing off the paper’s marvels of technology. Frank Jr., publisher of
the _N & O_, tapped the arm of a cousin who had just walked into the
room. “That’s your grandfather,” he said as the spooky old wax recording
crackled away in its new electronic incarnation.[4.11]

Josephus, though his racial views softened, reflected the separatism of
many Carolinians in the first half of the twentieth century. The paper
itself changed. It eventually hired Claude Sitton, a Pulitzer winner
notable for his civil rights reporting in his days with the _New York
Times_. The _N & O_ in some ways became the _Times South_. Reporters
fought racial injustices. Frank III portrayed the paper of that era as
never having met a cause it didn’t like. What’s more, he said the _N &
O_, although exposing politicians on the take, was too quick to
editorialize for local programs that raised local tax rates. I myself
favored the crusading kind of newspaper—in fact, one risk of a high-tech
orientation was that it could turn a newspaper into an uncritical
cheerleader for business if editors were not careful—but I could
understand Daniels’ concern over government spending. At any rate some
felt that the _N & O_ was losing touch with many readers, and so Frank
Jr. and the others on the board of directors agreed to let Frank III
serve as executive editor in the wake of Sitton’s retirement.

The contrast between the old and new editors couldn’t have been more
stark. Sitton was a formal man who insisted that his reporters wear
suits and ties. Frank III relaxed the dress code. In place of a sign
with his editorial title, he stuck up one that said simply, “Frat Man.”
Old-timers groaned that this young Duke alum lacked enough journalistic
experience. The man had been the newspaper’s _operations manager_.
Wasn’t it apparent? For each year of experience on the State side of
newspapering, you could subtract two years of experience with the
Church.

Even under Sitton, the reporters typed away on a modern publishing
system for newspapers. But that was more or less all they did—write.
Many could just as well have been pounding away on old Smith Coronas.
They hadn’t any desire to learn the technology, not when there were
doors to knock on, vote counts to check, political corruption to
chronicle, Ku Klux Klan rallies to report, and courthouse records to
search the old-fashioned way. Young Daniels set to work changing all
that, and with the most surpassing of allies. The news librarians almost
instantly grasped the potential of computerized databases. So did Pat
Stith, the senior investigative reporter. The _N & O_ would go on to
collect state records showing traffic or hunting violations, or others,
and then seek out patterns. “We analyzed all the speeding tickets,” said
Daniels, “and found out what percentage of tickets were given at each
mile-per-hour level. It turns out that if you go 63 miles per hour in a
55-mile-per-hour zone, you have less than a 1 percent chance of getting
a ticket.” Via the same quantitative techniques, the _N & O_ could
evaluate the programs of local government. By the time Daniels had
effected his transformation, he had squeezed dozens of personal
computers into an already-crowded newsroom.

A year or so after Frank Daniels III became executive editor, he first
beheld the Internet over at North Carolina State. “An engineering
student said, ‘Have you seen this?’ and he showed me Usenet. And about
forty-five minutes later, while I was thirty minutes late for a meeting,
I was speechless. I walked out. I was just buzzing with the
possibilities.” Daniels saw some engineering newsgroups and, yes, some
sexually related ones. “I couldn’t believe how many people I saw talking
together, just following each other’s conversations. The letters to the
editor at the time were the only connection the _News & Observer_ had
with its readers.

“Our business is connecting people. Here was a whole world that existed
without our knowledge. It was a small world and an elitist world, but it
confirmed my earlier belief that computers were going to be ubiquitous.”

Effortlessly Daniels understood that Usenet wasn’t Videotext—people
_wanted_ you to talk back. So the Internet was at least on his mind as a
possibility for the time when the numbers were right. Daniels for the
moment pushed into less exotic areas; for example, he started a useful,
lively, but expensive fax newsletter for the elite, _The Insider_, which
covered North Carolina politics with a commitment to detail missing from
the daily press. The _N & O_ also offered sophisticated research
services, using the databases it was amassing. And the paper let readers
dial up stories over the telephone through a technology known as
Audiotext.

The electronic action, however, really took off after Daniels hired
George Schlukbier, a computer-oriented librarian who had worked wonders
at the _Sacramento Bee_. Like Daniels the frat boy, Schlukbier flaunted
a few eccentricities within bounds. An electronic signature at the
bottom of his Internet messages identified him as “Chief Bull Goose
Looney,” a tribute to the giant Indian who terrorized Nurse Ratched in
_One Flew Over the Cuckoo’s Nest_, the Ken Kesey novel. Some, of course,
might argue that the Internet is itself a virtual asylum with the
inmates in charge.

Schlukbier and Daniels checked out Prodigy and America Online to see
about getting on those networks and decided that the numbers stank. Yes,
Prodigy-style services already had their networks in place, and the _Los
Angeles Times_ and papers in George, New York and elsewhere would go on
to sign up. But the _N & O_ concluded—rightly, in my opinion—that the
online services would need the newspapers more than the newspapers would
need the online services. Newspapers were the best source of steady,
detailed news about local communities. Each year the _N & O_ spent $12
million covering mainly local and state news, an amount that even a
giant like Prodigy could not replicate everywhere. “They’ve got their
view of the world that’s defined by whatever technology they adopted at
the time they started their service,” Daniels would later say. “We got
uncomfortable with the fact we’d be living their rules, and the
customers would be their customers.”[4.12]

Some other newspapers felt happy with Prodigy. “No,” said Mike Gordon,
an editor with Cox Newspapers in Atlanta, “Prodigy isn’t taking most of
the money.” What’s more, his online edition could enjoy revenue from
online ads. Still, more and more publishers were turning to the Internet
rather than Prodigy-type alternatives, and the balance of power changed.
When Microsoft started a new online service later, it offered newspapers
as much as 80 percent of revenue—at least several times the amount that
Prodigy had offered the _N & O_. (The Atlanta papers would themselves
end up on the Internet eventually, not just on Prodigy.)

Instead of relying on a Prodigy-style service, Schlukbier started a
locally oriented BBS with an Internet connection and a strong emphasis
on schoolchildren, not just the adult readers of today. This orientation
may have baffled many. Some newspaper publishers were too myopic to see
past the next quarter, especially if they worked for the big chains.
Exceptions did exist, of course. Knight-Ridder, for example, regardless
of its public ownership and its Videotext flop, was still pouring
millions into the new technology. As a family-owned newspaper, however,
without security analysts breathing down its corporate neck, the _N & O_
was especially free to experiment. Schlukbier believed that a decade
would pass before 40 or 50 percent of the homes in Raleigh were online,
and by then the children would be of customer age.

“By focusing on third-graders,” Schlukbier said, “I’ve got ten years to
learn from them what information they really need and want.”[4.13] What
they hoped for, in many ways, didn’t seem like a newspaper at all.
Rather they wanted their own tools. The bulletin board blossomed with
imaginary worlds in which, for example, Frank Daniels was the owner of a
fictitious newsstand. Children could wend their ways through cyberspace
by using written descriptions and computer commands to tell where they
were and what they were doing. George Schlukbier’s young son, Shane,
designed a mythical camp online with danger-ridden woods. Some may have
wondered how this applied to _newspapers_; I myself did. And then it
dawned: if newspapers would be increasingly two-way in the future, just
like the Net, then didn’t it make sense to see how the children
interacted with each other, as they did in role-playing games? The
children could change as they grew older, or moved away from the area
when their parents packed up for another job with IBM, but the
journalists could still observe the basic patterns.

The _N & O_ put more than 6,000 children and 700 teachers online for
free. NandOLand was the name of the educational service designed with
children in mind; a mouse click on a cloud, for example, would take
children to a NASA area on the Net. The students could send electronic
mail to each other or type to each other instantly. “I have seen
children who never cared what they wrote turn to a dictionary rather
than send a letter to a key pal with misspelled words,” said a teacher
named Stephanie Toney. “I have seen a child with a severe reading
disability sit for hours and concentrate on e-mail to another person on
the other side of the world. His English teacher would have given her
right arm to interest him in reading and writing for this period of
time.”

Granted, NandOLand wasn’t the entire solution to the needs of children.
Many couldn’t spend much time on a machine at school and lacked one at
home. But the program was much better than the alternative: expensive
school connections to the Net or no Internet at all.

Like the children, the _N & O_ itself was learning—about the local
schools and other institutions and the Net itself. “How many newspaper
editors and reporters get to talk with students, parents, and teachers
any time they want to without making a big deal of it?” asked
Daniels.[4.14] And so the educational coverage was better. Rosalind
Resnick, publisher of _Interactive Publishing Alert_, wrote that the _N
& O_ was “at the head of the pack when it comes to promoting
interactivity between its readers and reporters.” By the summer of 1995
every staff member, including those in circulation and advertising,
would be able to go on the Net from their desks. Daniels’ own Net
address showed up on the paper’s editorial page each day. The _N & O_
was publishing a dozen or two Internet items each month, complete with a
column called “Net Rider.” How different the paper was from a rival in
nearby Durham: “We don’t print many Internet stories,” a staffer there
said when I asked to speak to whoever covered the Net. The words were
spoken almost in a way to suggest that “Internet” was synonymous with
“_N & O_.”

Not everyone was happy with the _N & O_’s Internet service. Around 700
people had subscribed commercially by fall 1994, paying $20 a month, and
some rightly complained about the look and feel of the BBS and the busy
phone lines they had encountered during the summer. When I posted a
query on the Internet, at least half of the replies were hostile to the
online _N & O_. Some showed a knee-jerk hatred because they disagreed
with the paper’s politics. But others were right on target. The BBS
incarnation of NandO.Net, the name for the commercial part of the online
endeavors, was more of a rutted dirt road than an eight-lane information
highway. Customers for some months had trouble dialing up the service’s
modems for want of enough phone lines. Other glitches arose. The service
prided itself on the ability to whip people back and forth between the
local board and the Internet-related services without any effort. And
yet in making the transitions, customers suffered delays and software
glitches that they might not encounter with a more polished service.
Schoolchildren and BBS junkies were the best kinds of people to enjoy
the wild ride and the scenery.

The online _N & O_ responded with some technical improvements; the paper
added many more phone lines and gave customers the ability to use Mosaic
to point and click their way through the Web. Mosaic had a much smoother
feel than the BBS software. By late 1994 the _N & O_ was offering the
public an electronic newspaper and the Internet at the competitive rate
of $20 a month while helping to subsidize the educational side. And it
was serving people with different levels of equipment. The BBS was
designed to work especially well with less powerful machines and
snailish modems that were far too slow for Mosaic.

On the Net, the people who answered my queries had another major
complaint—the inability of NandO.Net to make alt.sex-style groups
conveniently available. Frank Daniels made no apologies. However liberal
towns like Chapel Hill might be, the state as a whole was of the
opposite bent. And that included more than a few church-goers in
Raleigh. “The community standards of our community don’t mix with some
of the sexual parts of Usenet,” Daniels said, “so we edit them out.” In
addition, most subscribers were children. “I have a seven year old,” he
said, “and I don’t want him delving into alt.sex.bestiality or those
other places.” Many of the Netheads would have said that one person’s
“editing” was another’s “censorship.” I myself, however, understood
Daniel’s worries. At least two other Net services were available in the
same area, so it wasn’t as if he were gatekeeping for the entire town;
what’s more, he said that when the software allowed, the sex-related
newsgroups would be available as an option. Just the same, the issue
epitomized the clash between the gatekeeping ethos and that of the
Internet.

More serious than the lack of alt.sex, to my mind, was Daniels’ failure
to appreciate sufficiently the political freedom of Usenet, the same
service that had attracted him to the Internet in the first place. I
complained to him that his own BBS included far, far less in the way of
political discussion than I’d have wanted, and I contrasted this to the
robust debates of Usenet. “To be honest, David,” he said, “I think one
of the least useful pieces of the Internet so far is their political
discussions. They’re not very good ones. There’s a lot of flaming. The
political discussions aren’t very productive. I follow mainly the local
ones here. These people discuss national issues and never have a
policymaker looking in there. So why discuss it if it isn’t going to
have an impact on policy?”

While Daniels was worlds ahead of newspaper editors at large, he was
showing the vestiges of the gatekeeping mindset that the new technology
had made obsolete. I myself disliked unmitigated flaming. And yet there
were times when harsh words were called for. The _N & O_ didn’t wimp out
when the editorial board attacked the Ku Klux Klan or the more
outrageous statements of Jesse Helms, the right-wing senator. Why should
people online be any different? And although it might be nice for a
policymaker to read my public messages as soon as I sent them out—and,
yes, I could recall hearing out of the blue from the White House after
one such posting—that was hardly necessary. Democracy isn’t just a
citizen writing to a congressman. It is also citizens communicating with
citizens, educating, proselytizing; and with the economies of Usenet,
more citizens could reach their peers for greater enlightenment. And
then, if a consensus were reached, political action might ensue, such as
letters to Congress. So why must politicians be involved from Day One?
Daniels was out of touch here, and I hoped he’d catch on.

Admittedly NandO.Netters could hook up with the Usenet political areas,
even if the _N & O_ played them down; but the newspaper didn’t really
promote political debates on the BBS itself. And it was not just because
Daniels believed that the readers disliked flaming and extremism—it was
also because he felt that real, live politicians were not ready for
online appearances yet. “When we can get commitment from the politicians
and policymakers, then we’ll make a push at it. But not until it becomes
something where our community can have really productive discussions. I
don’t want to train them not to like them. What happens is that the
people on the Net are trained not to like them. Extremists and flamers
love them.” I supposed there were a lot of us undesirables, however; for
alt.activism and similar areas were among the more popular newsgroups on
the Net—no match for alt.sex, but certainly not small time.

If Daniels had had a complete set of Net values, he would have
understood the benefits of debate online, and not just the political
action but the _education_. I myself was liberal. And yet when
discussing information policy, I could learn at times from the most
zealous of Libertarians and Objectivists. Some were among the most
advanced of the technologists. In fact, their technical backgrounds may
have led to their hatred of regulation—they loathed the bureaucrats who
could not fathom the direction in which computers and communications
were headed.

To his credit, Daniels at least was not calling for censorship of
Usenet; he was merely saying that he wanted his own service to be
different. What’s more, technology and marketing forces, the great
deciders of cyberspace, might change his mind for him.

Just as he had assumed in the first place, people on the Net wanted to
_talk_—not just to the _N & O_ but to each other about all kinds of
topics, including material in the paper itself. And the more comfortable
the readers grew with the online world, the more spirited, the more
Usenet-like, would be the discussions. No, the meek would not suddenly
turn into flamers. But the thrill of technology would be less of a
distraction, and they would pay more heed to what they had to say and
grow more adventurous about it. On the _N & O_’s present BBS, with its
often awkward commands, many people were not even leaving messages for
each other. Instead they typically used the system at a more primitive
level to type out their thoughts with the other person online at the
same time. I hated this approach. It brought to mind Dave Barry’s crack
that the Internet was like CB radio with typing.

Even if Daniels still did not enjoy the political debates on the Net
itself, he was living up to the old tradition of sharing material with
the rest of the world. In that sense his newspaper was exemplary. The _N
& O_ didn’t just offer news, discussion areas, and games for its
subscribers: Sample news and features were free to anyone who wanted to
read them. That was how I’d first run across A.C. Snow. I’d seen the _N
& O_’s name on a list of newspapers, and A.C. had caught my eye as I was
wandering through the Gopher that stored sample news stories and columns
from the paper. The World Wide Web, however, was the best way to try out
the electronic _N & O_. When I dialed up the main page for NandO.Net, I
could see a colorful, bluish logo and enjoy a newsstandish atmosphere,
with scads of goodies to explore. The _N & O_ differed from many
electronic newspapers. It didn’t just inflict on readers a digest of
generic news, with only the most cursory helping of original material.

I read samples from the regular _N & O_ and specialized publications
such as the _Insider_; enjoyed brief but regularly updated electronic
news intended for the Net itself; wandered through a little bookstore
with cover shots from books by Snow and other columnists; wended my way
through tens of thousands of words from a journalism seminar at Harvard;
soaked up long, multimedia features; dialed up samples of rock music;
and ventured into the sports area—the _N & O_’s most popular material on
the Web.

The sports area was the baby of a bearded, forty-something editor named
Eric Harris who had turned into a Nethead, and who like Schlukbier came
with a nickname: “Zonker.” A child, seeing the beard and taking in the
personality, had compared him to the Doonesbury character. That was a
little unfair. Zonker of the comics is a goof-off, while Zonker of the
Net is a workaholic whose messages might bear 4 A.M. time stamps. Harris
is Webmaster—the man with the daily responsibility for the content of
the Web area in general—but his true love was sports. He packed the
server with game schedules. During the ’94 baseball strike the _N & O_
indulged fans with whimsy such as “Cybersox Take the World
Series”—reportage of mythical games. “Need something to do while we wait
for the owners and players to resolve their differences?” the Web area
asked on another electronic page. “Well, the Baseball Server is doing
its part. Download the above images, tack them onto the wall, and buy a
set of darts. Then, every time you feel a twinge of baseball withdrawal,
grab a dart, think a ‘warm’ thought about one of the participants, and
let the fun begin.” And sure enough, Netfolks could print out pictures
of the villains, each of whom had a superimposed picture of a dartboard
and the wonderful caption: “The only losers are the fans.”

The _N & O_ also shared with the Net a variety of other material, of
which my favorite was North Carolina Discoveries. A lively feature
writer named Julie Ann Powers sought out offbeat places. In Lake Norman,
for example, she found that “houses and hangars ring the airstrip and
each lot comes with a grass taxiway to the paved and lighted runway.” In
Orient, a hamburger-and-hot-dog cook named Red Lee claimed that at
twenty-five cents each, his offerings were the cheapest in the country.
And in Tryon, the publishers of the _Daily Bulletin_ said that at 8 by
11 inches, their newspaper might be the smallest in the world. Powers
drove from town to town in a Ford Explorer that she had nicknamed
Barlowe after Arthur Barlowe—one of the first Europeans to behold the
state of North Carolina. Barlowe was a gadgeteer’s heaven on wheels,
full of audio and video equipment. People on the Web didn’t just enjoy
gloriously descriptive stories from Powers: with Mosaic-style software
they could _see_ a picture of her wearing a sun hat on a beach or gaze
at sand dunes or waterfalls or whatever she happened to be writing about
at the time. If they owned a sound card, they could _hear_, too. She
walked around carrying a microphone so large that it resembled a
folded-up umbrella.

Powers might well be one of the first multimedia reporters to work for a
Net-oriented daily newspaper. I asked her to share a few trade secrets.
She said she interviewed people twice. The first time she gathered the
basics for her regular story; the second time they spoke while tape
rolled. Powers said she never knew which sounds would work out and which
wouldn’t. A recording of a glorious waterfall ended up sounding like a
toilet flushing.

I asked about the challenge of balancing her traditional duties as a
reporter with those as an audio-oriented interviewer. Some old hands in
the _N & O_ newsroom saw the gadgetry as a threat. It was all too
remindful of the days when computers were replacing typewriters in the
newsroom, and many reporters and editors balked at being typesetters.
But Powers turned the new technology to her advantage. The microphone
and electronic camera—a photographer followed her around—made her more
aware of her surroundings and sensitive to new story angles. Once she
did a story on Ten Commandment Mountain. It was part of a Biblical theme
park, a peak in western North Carolina with God’s words spelled out in
“concrete letters each measuring five feet high and four feet wide.” A
roar from a giant lawn mower kept drowning out the voice of the man she
was interviewing. “They always ask,” he volunteered, “how do you mow
that mountain?” Presto, she had the magic quote to use near the lead. “A
special mower with a low center of gravity,” she revealed, “tilts and
leans up and down the steep planes.”

Whether reading about twenty-five-cent hamburgers or godly peaks, I
could scoot easily between pictures and words. The _N & O_ had a “North
Carolina Discoveries” logo at the top of one page, a picture of Powers
in the same area, and then a list of the Discoveries stories that she
had done. By clicking my mouse on a list of story headlines in blue
letters, I could immediately go to the stories. When I chose “Home Sweet
Hangar,” I sped to the same headline atop a color photo of an aviation
buff inspecting “his Cessna 172 after rolling it out of the hangar at
his house in Lake Norman Airpark.” Yes, the caption was there too. And
then I saw the story lead with an apt quote (“It’s like being an avid
golfer and living on the golf course”) followed by a list of other
items. I could choose “Audio: Talking about life on the flight line” if
I wanted to hear an interview. What’s more, if I’d set up my software, I
could even have picked “Video” and gone on to a list of short movies. I
also saw background items such as a list of “Triangle-area flight
schools” and “FAA regulations: How to get your pilot’s license.” The
beauty of this arrangement was that the _N & O_ could provide all kinds
of wonderful details for the interested without inflicting them on
others. Unless they mouse-clicked the appropriate words in blue letters
(or whatever the special color), they would never see the material.

The _N & O_ used the same approach on news stories. When North Carolina
was about to gas a man named David Lawson, readers could click on the
item “The Lawson Execution.” They could see a schedule of the events
ahead—from Lawson’s removal from his cell to the EKG examination that
would help certify his death. After the Associated Press reported the
execution, readers could click on a headline and read the details. They
could even summon up “Preparing for the execution” or “How the gas
chamber works.”

The Lawson story was a just a sample—the _N & O_ at the time wasn’t
constantly doing multimedia on breaking news—but it was easy to envision
the future for American newspapers using the Web. Imagine the blessings
for journalists who wanted to write on neat little odds and ends without
getting in the way of their main articles. They could merely add “links”
to offshoot stories. Perhaps the reader could even click and summon up a
collateral audio report or even a video. At first it might be hard to do
all this on deadline, but links would be a cinch as software improved.
What’s more, newspaper writers might evolve into true personalities just
like their counterparts on television. After all, if a reporter’s byline
were in blue letters, you could click your mouse to see a photo and
maybe even a bio featuring credentials—you could find out, for example,
if the legal reporter held a law degree. You could also quickly locate
copies of earlier work or a list of his or her favorite books.

Granted, electronic newspapers posed new challenges. Not all stories
lent themselves to multimedia, for example. What if newspapers played
down those that didn’t? “If you tried to do that with a lot of news
stories,” Julie Powers told me, “you would end up serving the video
masters rather than the news functions.” Still, in the end, the reader
would enjoy far more choices than before.

The Web, as I saw it, held out yet other possibilities for local papers
such as the _N & O_. Suppose you lived in Chapel Hill and wanted to see
what news had happened there in the past 24 hours; you could click on a
map of the Raleigh area and behold a story list from your town.
Neighborhood-level submaps could show still more. You could read the
most minor tidbits—for example, new requests for zoning changes or items
from neighborhood newsletters. Even more helpful, you could find old
stories and other background information. Let’s say you were shopping
for a condo on a certain street. You might think the neighborhood was
safe—Chapel Hill is a university town, remember—but learn that many
crimes had occurred nearby. Furthermore, you could adjust the _kind_ of
information that you summoned from the Web. For example, you could see
lists of houses for sale in a neighborhood and then retrieve their
photos along with audio sales presentations. Moving on to another
information category, you could uncover lists of nearby stores or see
test scores from the closest elementary school. And you might even see
ads from nearby restaurants and click on them to order.

The food-related examples weren’t entirely hypothetical; Zonker Harris
pointed me toward me some mock ads from Hardee’s and a chain called
Little Caesar’s Pizza. The same business principles I discussed in
chapter 2 applied here. Rather than planning to inflict vast quantities
of material on the unwilling, the _N & O_ made the ads useful and
entertaining. Elsewhere in the _N & O_ area I saw an ad for a computer
dealer, among others, but the real triumph was the area from Mammoth
Records—with home pages for bands, promo photos, discographies, tour
dates, album covers, and more, including a catalogue and, yes, free
samples.

But what about the economics of all this? Via an electronic edition the
_N & O_ wouldn’t collect the fifty cents it charged per hard copy issue,
but it wouldn’t have to buy newsprint and distribution services. _That_
was how George Schlukbier hoped the newspaper would turn a profit
eventually. The electronic activities, although not yet profitable as a
whole, were coming along. People on the Net, for example, were calling
up the pages within the _N & O_’s area several hundred thousand times a
week. A page was what you saw when you clicked the mouse to call up an
item, and each page could be just a few lines of information, or go on
for a number of screens. Zonker Harris expected that by the end of 1994
as many people would be dialing up the _N & O_ as called up SunSite UNC,
the popular collection of files at the University of North Carolina.
Readers retrieved Mammoth Record’s pages some 35,000 times a week. That
didn’t mean 35,000 people—there was plenty of repeat business, and of
course the same people looked at more than one page—but the numbers
looked good as a start.

Just who, however, was reading the Web areas of the _N & O_ and other
Internet publications? The _Washington Post_ and many other dailies had
chosen to avoid the Net for the moment because they thought that the
right people weren’t there. And some marketers and journalists tried to
reinforce such arguments by citing a study of 4,777 Web readers by
researchers at the Georgia Institute of Technology. Ninety-four percent
were men, and 56 percent were 21-30 years old—almost half were students
or faculty members or had other university ties. “These are hardly the
type of people to make large consumer or business purchases,” a _San
Francisco Chronicle_ story observed. The experience of JoAnn and Bob
Lilienfeld, as recounted in chapter 2, showed that riches would not
automatically come to merchants on the Web. And yet the potential was
there. The Web readers uncovered by the institute weren’t charity
cases—just yups. Studying the readers of the Baseball server, the _N &
O_ found they were a long way from poverty. Twenty percent of these
Netfolks, for example, earned $35,000-$50,000 a year, 18 percent earned
$50,000-$75,000, and 4 percent earned more than $75,000. And, of course,
many of these Netfolks were young people who would carry their Net habit
over to their jobs and their personal lives. Not surprisingly,
Schlukbier claimed keen interest from representatives of companies such
as J.C. Penney and Radio Shack, and, of course, from fast-food chains,
which, in so many cases, targeted their ads at the young.

Cleverly the _N & O_ built on existing relationships with advertisers.
If you were already on the paper and bought _X_ number of lines, then
you could get the Net as a bonus. North Carolina businesses paid as
little as $50 a month in basic fees to be in the _N & O_’s area on the
Net, not including add-ons such as design services. Big national firms
would pay well into the thousands. Given the newness of the medium, this
would scare off many—unless, like the _N & O_ itself, they saw the Net
as an investment in the future. Then the experiment might work. In my
mind, however, there was one other variable: What about _national_
publications competing with local papers for the same _national_
advertisers? Already Time Warner and the _N & O_ were watching each
other carefully.

Magazines: Time Warner

Typing away on Macintoshes on the fortieth floor of the Time Life
Building in Manhattan, ten floors above _People_ magazine, a small team
started an area of the Web known as Pathfinder. It offered electronic
versions of Time Warner’s vast stable of magazines. Zonker Harris at the
_N & O_ had a slogan, “May the best server win.” The Durham newspapers
might not be in the game so far, but _Time_ and brethren were.

Zonker was justifiably proud of the 300,000 or so accesses a week that
the _N & O_’s Web area was enjoying after several months on the Web. But
just within a week of start-up in fall 1994, the Time Warner area was
drawing more than 80,000 accesses a _day_. That didn’t mean that the _N
& O_’s efforts were doomed—hardly. But despite all the talk about the
Net being nirvana for smaller companies, Fortune 500 corporations
arrived with some advantages of their own. Once readers grew comfortable
with a certain area of the Web, they might spend less time on other
parts of the Net. This wasn’t so much a pattern at the time, but as mass
audiences descended on the Net, corporate logos might count far more.
Beyond that, Time Warner already offered a daily version of _Time_—a
_newspaper_ in effect. It was just one service among a rackfull of
publications. Readers could read up on foreign policy or the latest
_Star Trek_ film in _Time_, take in reviews from _Entertainment Weekly_,
keep up with Ice-T and other hip-hop musicians in _Vibe_, or fire off
questions to authors of best-sellers from Warner Books.

An even greater threat to the _N & O_, in the long run, was the fact
that Time Warner didn’t just own magazines and book publishers. It also
owned _pipes_, including a cable operation in the Raleigh area. And
someday it might use cable TV lines to send the Net into homes there,
competing with the _N & O_, which had already been providing Internet
services. If no antitrust or other legal boundaries existed, then Time
Warner would be remiss in its duties to its stockholders if it did not
explore this route. Think what this would mean to users of the World
Wide Web. If an article came with fancy photos, they might have to wait
several minutes for the whole works to reach them at a speed of 14.4
kilobits per second. But suppose Time Warner used cable TV to bring the
Internet to them. Their televisions would still work with cable the
usual way. But their computers could share the cable and retrieve Web
articles and other material in a fraction of the time. Cable modems sold
for hundreds of dollars. But pilot projects were going on with other
companies, and the cost could soon drop to a fraction of that amount.
More important, big, well-financed corporations might be willing to
modify the old cable for these new capabilities.[4.15] What did this
mean for local, _N & O_-sized companies? Just as high tech had blurred
the difference between telephones and televisions, the Net itself was
blurring the barriers between local and national. It was unclear whether
the public would win or lose.

For better or worse, Time Warner’s area on the Net was part of an
evolution in cyberspace. The process had begun with the small academic
magazines and hobbyist publications that turned to the Net as a cheap
way to find readers. Many if not most still relied on plain text without
graphics; they were little more than archived dispatches to mailing
lists—which was fine because the words mattered above all. One of the
best of these was Adam Engst’s _Tidbits_. Written for Apple owners, it
also appeared on the World Wide Web and bulletin board systems, and
Engst claimed more than 100,000 readers—no small feat for a
kitchen-table-style publisher. Nonconglomerates still provided most of
the magazines on the net, and not all were for techies or sci-fi buffs.
_International Teletimes_ was edited by Ian Wojtowicz, a gifted high
school student who lived in Vancouver, British Columbia. _Teletimes_
went out over the Web with fetching art, not just text, and some of the
prose could have graced _Harper’s_ or the _Atlantic_. Recounting a
winter trip by train, a college student named Paul Gribble wrote: “Every
now and then we pass a lake, completely frozen over, flat and white,
smooth as a skating rink. I’d love to walk to the center of a big frozen
lake like that and just sit there for a while. I’d feel like the first
blot of paint on a fresh silk canvas.”

Many steps up from _Teletimes_, in business terms, was _Global Net
Navigator_. Like the _N & O_ in North Carolina, _GNN_ was trying to use
advertising to support its activities, and you could see ads from
companies as large as Digital Equipment Corporation. _GNN_ was not just
technical. It posted informative, brightly written articles on topics
ranging from money to food and travel. _Wired_ magazine was on the Net,
too, with an offshoot called _HotWired_, which itself wandered far from
technical topics and attracted lucrative ads from the likes of Volvo and
AT&T. None of these publications, of course, happened to be a Household
Name like Time Warner’s _Time_ or _People_. Many experts felt that as a
profitable medium for big-time magazines—and let’s not confuse size with
quality or lack thereof—the Internet had a long way to go.

Jeffrey Dearth offered at least an interim answer. Teaming up with a
small corporation with the grand name of the Internet Company, Dearth
offered the Electronic Newsstand. Like the Pathfinder or _N & O_’s Net
edition, the Newsstand was a godsend to browsers. You could wander
through sample articles from _Business Week_; _Field & Stream_; _The
Economist_; _The New Yorker_; _National Review_; _Maclean’s_, Canada’s
largest newsweekly; or The _New Republic_, of which Dearth himself was
publisher. The Time Warner experiment notwithstanding, most of the Names
were far behind. Dearth offered them the equivalent of a catch-up course
or at least some solid remedial instruction. They could test the waters
of the Net to see how much interest their articles drew, before deciding
whether to set up their own areas there. Via the Newsstand, magazines
could accept subscription orders.

But order taking was a long way from fancier “interactivity”—to use a
pet term of media people—and this was where Time Warner’s Pathfinder
area would shine. The area didn’t just recycle magazines on the Net, it
also offered powerful tools to find old articles by typing in search
words or the names of topics. From the start, the searching capability
was among the more popular services. Soon Pathfinder would include
hypertext links that let you go from an article on a certain topic to an
ongoing discussion. Already Time Warner provided special services such
as one for gardeners. They could type in their general wishes about
flowers and supply their location and other odds and ends, and then Time
would offer tips on what to grow. It also allowed inquirers find out how
their congressman or senator had voted on certain key issues. And many
more applications like this were on the way. What’s more, people could
talk back to Time Warner writers and others by way of an advanced
bulletin board system designed for the Web. It was _much_ easier to use
than the _N & O_’s.

Not everyone liked the Web area. One woman hated the “overstuffed”
artwork—others said it gobbled up too much downloading time. She also
chided _Time_ for putting out the online version of _Sunset_ magazine
“for Northern Californians still living in their ’50s ranch houses.” I
myself, however, enjoyed the kitsch and flashy, busy look of the Web
area as a whole. That was the way the _real_ magazines came across; this
was pop culture, not the _Kenyon Review_.

Almost immediately the _Time_ board teemed with lively talk on issues
ranging from Clintonian stupidities to, yes, the future of the
electronic medium. I felt much more comfortable here than in the message
area of the _N & O_; people on the _Time_ board spoke their minds more
freely. Some amusing posts showed up. Amazingly, the software let people
key in their own identities, and the late Henry Luce, cofounder of
_Time_, arose from the grave as luce@pastmytime.com. One message
appeared, truthfully or not, with the name of a staffer at _U.S. News &
World Report_. He promised that _U.S. News_ would set up an outpost on
the Net soon, and someone at _Time_ twitted him for not answering e-mail
promptly. Despite my fondness for the reporting in _U.S. News_, I had to
agree. Researching a Net guide for political activists, I’d written
_U.S. News_ six months ago and had yet to receive an answer.

Time Warner also showed network savvy by following the example of _GNN_
and similar publications and providing some hypertext pointers to the
rest of the Internet, rather than expecting readers to stay within its
own area. Time Warner even enlisted some of its household names in the
cause. The electronic version of _Entertainment Weekly_, for example,
did not just review Madonna or Springsteen or the latest Hollywood
films; it also directed people to popular, entertainment-oriented sites
on the Net itself by way of hypertext links. I still wanted to see many,
many more links—a strength of _GNN_. But I suspected that would come in
time.

Planning the Pathfinder service, Time Warner had even consulted with the
publisher of _Wired_. “They’re providing real news, not just PR blather
or sales areas for their products,” said Chip Bayers, the managing
editor of _HotWired_, the _Wired_ offshoot on the Web. And he was right.

I myself was no cheerleader for Time Warner in some ways—I worried about
media concentrations.[4.16] But here the Suits deserved their due.
_HotWired_ offered avant-garde graphics on the Web along with services
such as bulletin boards and free archives; I was pleased, yet hardly
surprised. _Wired_, after all, was still a bit of an upstart despite
heavy investment from a corporate arm of the powerful Newhouse
family.[4.17] But Time Warner was different—the epitome of the
journalistic and Hollywood establishments, a company with many benefits
from the status quo. I recalled the upbeat stories that _Time_ had run
about the world of 500-channel television. Such articles betrayed far
more tolerance of the “one to many” broadcast model, as opposed to the
newer, more anarchistic model of the Net. Many in the Time Life tower,
especially on the entertainment side, might still harbor these less
adventurous visions. And yet the company was now spreading its bets
around. That seemed sensible enough, given the chilliness that some test
markets had shown interactive TV.

A _Time_ writer named Philip Elmer-DeWitt had grown more and more
attuned to the potential of the Net. He was a regular on The WELL, the
bulletin board system frequented by many of the elite journalists on the
Internet. Again and again Elmer-DeWitt showed up on newsgroups and
mailing lists with spunky, opinionated posts on such topics as the media
and telecommunications. He lent his name to a successful legal campaign
to aid Brock Meeks, a small publisher on the Net who faced a libel suit
from a mail-order tycoon in Ohio. What’s more, Elmer-DeWitt was
sensitive to the threats from the Clipper chip, which Washington might
use someday to invade the privacy of millions of Americans. He clearly
represented the interests of his employer, but he did so with a good mix
of wit and smarts that endeared him to many on the Internet. His
electronic signature said, “Read Time on America Online where we are
paid to take abuse.”

Enlivened by posts from Netfolks and WELLfolks whom Elmer-DeWitt had
befriended, _Time_’s message board thrived on America Online. But now,
quite correctly, _Time_ had run an article pointing out the advantages
of the Internet from the perspective of publishers. _Time_ raised a big
question, the same one Frank Daniels had asked. Did publications really
have to fork over such a hefty percentage of their online revenue to
commercial services, such as America Online, when the Internet existed?
Time Warner’s well-stocked area on the Net was itself an answer of
sorts. Granted, the company’s outpost on America Online wasn’t about to
vanish. Time Warner was testing both interactive TV and computers as
transmission vehicles; similarly the company was not committing itself
to any single network in cyberspace. I took it for granted that sooner
or later Time Warner might end up on the network that Bill Gates was
starting. Just as _Time_ reached newsstands everywhere, the electronic
equivalent could seek out eyes wherever the phone lines led. _Sports
Illustrated_, _Fortune_, and _People_ would soon be on CompuServe. And
yet Time Warner’s priority in the computer world was clear: the Internet
above all else, at least for the moment.

“When we put _Time_ on America Online,” said Walter Isaacson, editor of
new media at Time, “it is done on their server, using their software,
and only someone subscribing to America Online and using America Online
software can access it. On the Web, anyone using public domain software
can get to it.” I could just have substituted “_News & Observer_” for
“_Time_,” an impression only strengthened by the next sentence: “We have
a direct relationship to our readers.” Isaacson went on: “There will be
massive amounts more content from Time Inc. on the Web than on America
Online or CompuServe, which will just feature individual magazines.”

Some twenty-two magazines were to go on the Web. Isaacson said around
ten editors would participate full or part time. Total investment in the
Web site was to reach the “mid six figures,” and “with advertising it
should be in the black within a year.” “There may be a mix of ads and
subscription fees,” Isaacson said. Mercifully, the advertising would not
be the intrusive Prodigy kind that popped up on the bottom of my screen
in a garish, Vegas style.

Jim Kinsella, the ex-newspaper editor who presided over the Web area,
said he was pushing for a subscription fee of around $8 a month. I would
have wanted the price to be a few dollars lower, but it was fine if I
got enough for my money. If nothing else, Kinsella wanted readers to be
able to stay online without the time charges that made thousands unplug
their hookups with America Online and similar services. A product
manager with Microsoft would later say as much to the _New York Times_
in discussing Bill Gates’ new service: “We’re trying to reduce the
threshold of pain. We think users hate connect fees.”[4.18]

Kinsella’s $8 monthly fee—his proposed figure, not Time Warner’s—would
be for Pathfinder itself, not for the Internet connection. I did some
quick math. Pathfinder could indeed be a competitive possibility if Time
Warner were able to lower the cost of using the Internet by way of cable
television from the $75-$100 a month that people typically paid for such
arrangements.

Mass use might enable Time Warner to undercut the $20 that the _N & O_
presently charged. Typical readers might want to keep reading a _local_
newspaper, and the _N & O_ could drop its own prices, but this was still
a good example of how national media just might drain at least some
readers away from the local media. Understandably, Kinsella was thinking
in mass, national terms, as I would have done. He predicted that within
five or ten years half the country might be able to reach the Net in one
way or another. Others at Time were similarly optimistic.

Not everyone in late 1994 was so sanguine. Mark Stahlman, for example, a
media expert in New York, shrugged off Net publications as “just the
latest in a series of fads.” Richard M. Smith, _Newsweek_’s editor in
chief who was running the new-media committee of the Magazine Publishers
of America, was skeptical about online services in general: “The people
who are making money are the people who are running conferences about
it.”[4.19]

Smith was oversimplifying somewhat, but formidable barriers did exist,
of which one of the biggest happened to be the limits of the technology.
Reading electronic text for hours on end could be murder on both the
back and the eyes. All day long I sat in front of a computer screen; the
last thing I wanted was to have to do it while I wandered through
magazines or books. Television wouldn’t do: I hated the idea of reading
a magazine or novel from ten feet away. Besides, didn’t magazines and
books exist to be enjoyed in bed, on the hammock, or at the beach?

Mightn’t Silicon Valley, however, come out with small, tablet-style
computers designed for reading? “TeleReaders” could feature optional
keyboards for people who wanted to use them as general purpose
computers. Screens, needless to say, must be much sharper than today,
and without so much flicker. Batteries should last longer. And, ideally,
you should be able to dart from place to place in a newspaper or
magazine by merely touching a “pen” to the appropriate part of your
screen. _That_ was what the magazine, newspaper, and book industries
needed, rather than just more conferences. Washington could even
encourage this by way of a focused procurement program for schools and
libraries; the same machines could even be used for electronic forms for
government and commerce.

Roger Fidler of Knight-Ridder had already been experimenting with
mockups of tablet-style machines. He was more interested in a
newspaper-oriented approach and less in a general one than I was. But
the basic idea was the same—words needn’t be captives of the printed
page. The real question was this: How soon until the right technology
appeared? Electronic magazines such as Time Warner’s would still make
money without a TeleRead-style approach, but the full potential would
not be reached, especially if more children abandoned words for TV and
computer images. That was even truer for the world of books. Even more
than magazines and newspapers, e-books suffered from the limits of
technology. It wasn’t just a question of the right machine for viewing;
at issue were other matters such as copy protection and billing. But at
least some partial solutions were on the way, and even with the present
difficulties of the medium, online bookstores were sprouting up on the
Internet. One of the best was run by Laura Fillmore, an editor in
Massachusetts who had once worked for Little, Brown.

Books: Laura Fillmore and
the Online Bookstore

An elderly man owned a charming old store in a southern town with the
standard magnolias, wrought iron staircases, and hot, moist summers, and
he loved to brag about his shiny new safe. Most customers did not know
about it or care. Rather than worrying so much about the protection of
his wealth, he might have been better off to imitate his rivals and
invest his money in air-conditioning instead of the safe.

The man reminded me of myopic publishers and authors. Not quite grasping
the full potential of the Internet, they fretted too much about
copyright protection, and not enough about making their wares friendly
to shoppers. A pay-per-read company in Virginia was typical here. You
could download its books off the Internet, but you did not enjoy such
niceties as links to other titles online. Nor could you print more than
a page or so at once. Beyond that, you had to clutter up your computer
system with a $25 gadget hooked up to the printer port. If you were
working on tight deadlines and were rich and desperate enough, you might
stomach this copy protection system. But I dreaded the possibility of
its adoption by the book industry as a whole; established publishers and
writers just might see the world pass them by if they cared too much
about cybersafes and not enough about customer amenities. Many megabytes
of good, free reading awaited the public on the Web, and not everyone
understood the value that professional editors and writers could add.

Nowadays, however, more publishers and hangers-on were catching on to
the nuances of the Net. Among them was Laura Fillmore, a publishing
consultant who owned the Online BookStore in Rockport, Massachusetts.
She must have driven some traditionalists crazy. Fillmore actually had
the notion that ASCII—text in a popular format, without italics and the
other trimmings—should be free to everyone. She loved Project Gutenberg,
which an Illinois academic had started to put classics and other works
on the Net at no charge. Fillmore was the antithesis of a techno-geek,
the kind of woman who just might read Dickens to her two children on
snowy days, and who was a regular on the speaker circuit within her
industry. She had majored in English at Barnard College and worked for a
publishing company that dated back to the nineteenth century. Fillmore
helped bridge the past and the electronic era. Her vision wasn’t quite
the same as mine, but it was worlds apart from that of piracy-fixated
publishers who saw electronic readers as a criminal class.

The move to the Net was, in her opinion, part of a long evolution toward
a new form of decentralized publishing. She recalled when the great
houses didn’t farm out editing and other tasks as often as they do
today, and when almost every book took nine months to reach the stores.
“Back in the late ’70s when I was at Little, Brown,” she said, “we
needed to get special permission to use Ex. When an author wanted his
sales figures, I’d walk up the street to the top floor of a separate
building where Rose, the lady with the P & L cards, had been keeping
tabs for twenty years, and I’d sign out the neatly penciled card and
carefully carry it to my boss, wrapping it in plastic against the
weather if necessary. I passed the copyediting department with their
well-stocked reference library, a bastion against inaccuracies, and the
design department, smelling of wax, hung with rulers, sizing wheels, and
X-acto knives.”[4.20] The industry, though, had changed; now freelancers
throughout the country, not just in New York or Boston, were often
editing and even publishing books. Fillmore herself had gone into
freelance editorial work years before, and she still remembered “the
shrinking feeling in my stomach the first time I bought a computer setup
back in 1984: $10,000 of the bank’s money for an XT and an HP LaserJet.
The salesman left, I was back at the C prompt, and the room grew dark.
No matter which buttons I pushed, ‘Abort, Retry, Ignore’ glared back
persistently. Finally, I chose none of the above and unplugged the whole
thing.”[4.21] Fillmore overcame her technophobia, but the chaos of
change still made her uncomfortable. “Increasing speed and volume have
led to high job turnover, a blurring of disciplines. Our computerized
tools allow the editor to become a typist, a designer, and a
type-setter, the designer becomes a software junkie, a graphic artist, a
prepress house. No time for galleys! Straight to pages! No time for
pages; straight to film. The drop dead date is bottom line. Sales are
needed this quarter.”[4.22]

Years ago, competition had reached the point where many typesetting jobs
left the United States. “We even hired freelancers thirdhand in
Singapore and Haiti,” Fillmore recalled in a speech. “The publisher
hired me; I hired someone stateside to hire someone in-country to hire
the keyboarder and, still, the publisher ended paying maybe half what
the job would have cost him at $15 per hour. Our topic today is
slavery.”[4.23]

But in Fillmore’s opinion, this distributed form of publishing, where
tasks went every which way, would take a newer and more humane form. In
the 1980s books had appeared on computer networking, a kinder technology
than the brutal, production-oriented variety of the past. And now
Fillmore saw in networks a chance to “elicit life from people” who used
computers to communicate. Her own “epiphany” came when a Net-oriented
writer, John Quarterman, author of _The Matrix_, introduced her to “the
then alien concept of electronic mail. My assistant would pick up mail
from my lone correspondent, the author, print it out, put it in my in
box, and I would handwrite responses which she would input and send back
in due time. It sounds quaint, but it seemed to make sense to me at the
time—in the same way computerized typesetting distributed though
unconnected PCs made sense.” On the Net, everyone could publish, not
just giant publishing houses. And so Quarterman could forward to her
some public messages from students who were defying the Chinese Army in
Tiananmen Square. They could speak for themselves; no one edited them.
They weren’t like the freelance typists in Haiti: They were not “hidden
and voiceless behind four middlemen” and “with no hope of a phone, much
less an Internet connection.”[4.24]

The overlap in Fillmore’s mind, between publishing and communicating via
the Net, was entirely natural. When the Haitians typed, they created a
digitized version of the book they were working on. They were not just
transferring words to paper. Bits and bytes, once created, could go
anywhere.

Fillmore, of course, was hardly the first to think of consolidating
knowledge. As early as 1945 a scientist had published a preternaturally
farsighted _Atlantic Monthly_ article that was to electronic publishing
what Leonardo da Vinci’s notebooks were to inventions in general.
Vannevar Bush had proposed a memex, a microfilm-based device that could
bring together knowledge from many disciplines—along with the thoughts
of the user. It would be, in other words, a cross between a personal
file cabinet and a giant library. In a speech, Fillmore quoted a key
passage: “The human mind ... operates by association. With one item in
its grasp, it snaps instantly to the next that is suggested by the
association of thoughts, in accordance with some intricate web of trails
covered by the brain.”[4.25] Bush might as well have been describing the
World Wide Web and its links that allow you to click on “Boeing” and see
“Airplanes” or click on “Clinton” and see “Presidents.” Ted Nelson, a
dreamer-writer-programmer, was thinking of the memex when he invented
hypertext links. That concept, in turn, excited Tim Berners-Lee, a
staffer at a physics institute in Berne, Switzerland, who was the father
of the Web—the vast network of computers through which I could retrieve
the Raleigh _News and Observer_, _Time_, and Fillmore’s offerings.

Back in 1992, however, the World Wide Web was a fraction of its present
size, and programmers had yet to release easy, graphically oriented
browsers such as Mosaic that would help tame the Web. Even more than
today, people needed books to fathom the Net. And yet no popular-level
guide was in print. So it was entirely fitting that when Fillmore
decided to create a book from scratch—rather than just produce it for a
publisher—the Internet was the subject. This how-to guide was _The
Internet Companion_, the author was Tracy LaQuey, and the paper
publisher was Addison-Wesley. Fillmore kept the network rights and
looked forward to distributing the book through her new Online
BookStore. Barry Shein of Software Tool & Die, the first commercial
service to hook ordinary mortals into the Internet, had offered her
space on his bank of hard disks. “He described his operation,” she said,
“as basically an electronic store with empty shelves and a cash register
at the door. I decided that I’d find electronic properties to fill these
shelves.”[4.26] But the Internet at the time had Acceptable Use Policies
that prevented her from making a profit. What to do?

Fillmore hit on a solution that actually rewarded her for an idealistic
approach to publishing. She gave away—with great luck in the end—ASCII
files from the book in hopes of drumming up interest in the paper
version. “Who wants to read hundreds of pages in ASCII anyway?” Fillmore
would later ask. Unadorned ASCII by itself wasn’t always that pleasant
to read, and many people liked the Net version well enough to shell out
money for a paper book. “Even our publisher was supportive of our
effort,” Fillmore said, “and happy with the resulting sales
figures.”[4.27] Orders poured in from as far off as Finland and Korea.
Netfolks all over the world could learn of Fillmore’s offering
immediately rather than waiting for reviews to show up in local
magazines and newspapers.

Within two years, _Companion_ had sold hundreds of thousands of copies.
Al Gore had written the foreword just before his election as vice
president, but the freebies on the Net certainly hadn’t hurt. Other
publishers also found that free copies could be a boon, not a bane. _Zen
and the Art of the Internet_ (Prentice Hall) and _The Hacker’s
Dictionary_ (MIT Press) similarly flew off the racks. “Giving something
valuable away for free,” Fillmore said, “can make money.”[4.28]

Of course some would say she hadn’t actually published online. Rather
she had used the medium to promote a paper book. Still, the prospect of
purely electronic publishing beckoned. “I was seduced by the prospect of
the then 10 million people on the Internet—10 million literate people
with disposable incomes—attached to the Net. Why not acquire lots of
Internet rights to lots of books and put them online at the Online
BookStore. Surely some percentage of those people would buy files of a
popular author’s books for a reasonable price.”[4.29] Fillmore was
sensible enough to price her offerings for consumers who were spending
their own money, not their bosses’. Some commercial databases were
charging as much as $200 per hour or more, while Fillmore was thinking
more in terms of $5, say, for a short story downloaded from the Net.

The test story was “Umney’s Last Case,” a fifty-page Stephen King story
from a collection called _Nightmares and Dreamscapes_. King was among
the best-selling writers on the planet. Fillmore dreamed of tens of
thousands of dialups even if “Umney” intrigued only 1 percent of the 10
million people on the Net at the time. Fillmore had picked out just the
right King story, one where a time traveler gave a Toshiba T-1000 laptop
computer to a tough detective around 1939—someone who in turn used his
“plastic Buck Rogers steno machine” to write a story within King’s own
tale.

Fillmore’s “Umney” project was a sensation at the biggest book fair in
the world, the one at Frankfurt; upbeat stories appeared in places
ranging from European news programs to the _Wall Street Journal_. She
witnessed “a vast amount of smoke, a tremendous marketing boost for the
printed book again, lots of noise—and by extension, lots of profit for
the publisher and for the author—but handfuls of per-copy sales.”[4.30]
They didn’t even pay for all the phone calls used to set up the deal.

I was hardly surprised. Enjoying access to many megs of free material on
the Net, the typical denizen didn’t want to shell out even $5 for the
story even if she or he could simply fax in a credit card number. It
wasn’t that King’s work was worthless—quite the opposite. Rather, on the
Internet and with this business model, “Umney” at most any realistic
price could not compete with free material such as Usenet postings.

Yes, the Net teemed with sci-fi and fantasy fans. But as I saw it, they
were too busy talking to each other, and, while they would have been
delighted to download “Umney” for free, they balked at spending the $5.
You might say that “Umney” was like a typical TV program. The appeal was
potentially broad but not deep. Pay-per-view wasn’t that much of a hit
on cable TV, and the same principle applied here. “Umney” could enhance
a collection of material for subscribers—we go back to the flat-fee
example of the _News & Observer_ and Jim Kinsella’s vision for Time
Warner—but even a Stephen King story wasn’t strong enough on its own for
online use. Part of the problem, I believed, was the medium. The right
technology for reading fifty-page short stories just wasn’t out there
yet. With the proper equipment, the value would increase.

Besides, even now, Fillmore could use a license or sponsorship model.
She sold “Umney” to two computer networks, one of them CompuServe, which
gained the right to post the story for a week during a conference on
paperless publishing. “Hundreds of people have accessed it,” Fillmore
said. The future possibilities were evident now. Corporations someday
might sponsor books on computer networks the way they sponsored programs
on CBS or NBC. In fact, whole sites on the Net—with the names of
companies—could serve as homes for innovative projects. Sun Microsystems
was oriented toward UNIX, relied heavily on sales to Net users, and
benefited from the goodwill and publicity that its SunSite libraries
enjoyed. Fare ranged from presidential speeches to the Internet
Underground Music Archive; there could be a place for commercial e-books
as well in these high-tech sandboxes, as Fillmore jokingly called such
areas.

The sponsorship model wasn’t perfect, of course. Fillmore herself was
the first to wonder which corporations would have sponsored writings
about the uprising in Tiananmen Square. Big companies often favored
upbeat material. As I saw it, fiction and nonfiction books alike might
suffer if this model alone prevailed. They differed from newspapers and
magazines; book publishers thought more in terms of individual
properties, and beyond that, publications such as the _N & O_ and _Time_
already enjoyed strong identities from their paper incarnations. The new
media were less a challenge to their editorial integrity. But many
sponsored books might degenerate into the Net equivalent of the wretched
infomercials on TV, the ones where over-the-hill actors “interviewed”
astrologers or memory experts, and where the audiences clapped
thunderously on cue.

Wisely, Fillmore did not give up on “Umney” entirely—it was still online
when I was writing this chapter—nor did she quit using the Net to
promote writings on paper. Even more important, she tried out writings
that took advantage of links to other material on the Web.

_Bless This Food: Amazing Grace in Praise of Food_ was an example of
prime material for hypertext. The paper book bought together
food-related prayers from many times and places. But everything was
contained. You couldn’t wander outside the printed pages. Thanks to
Fillmore, however, you could click on Buddhist-related material and see
a Buddha’s image piped in from the Smithsonian. You could even e-mail
the author of _Bless_, Adrian Butash. Fillmore wasn’t just selling the
book itself—she was offering it as a “dashboard” that could take you to
related material on the Net. Certainly the Smithsonian hadn’t had
_Bless_ in mind when it posted the picture of Buddha. However, through
the pointers in the electronic edition, you could learn of this image
and view it in just the right context; that, after all, was the splendor
of the Web. Quite honestly, then, Fillmore could charge $25 for a book
that sold in hardback from Delacorte for $18.95. She was giving you
_more_ for your money. Besides, if you proposed new links and she liked
them, you would receive some royalties. You, the reader, could be part
of the book and the author’s life. We could all be editors.

As a writer, I had somewhat mixed feelings about this. I loved e-mail
from readers. But I was already spending too many hours a day on
electronic correspondence of one kind or another. I hated the idea of
suffering a constant stream of e-mail from Project X when I wanted to
move on to Project Y. If this model won out, writers would have to be
much choosier about the projects they took on—knowing that publishers
expected more commitment.

Given the deluge of 50,000 titles a year that readers face just from
U.S. publishers, more than a few people would enjoy such a prospect. But
they shouldn’t grow too complacent. With electronic publishing much
cheaper than the paper variety, we might eventually see 100,000
commercially published titles a year. I, for one, wouldn’t mind as long
as quality and royalties don’t suffer. The problem is not too many
books, but rather the need for better software to sort through them—or
for more hypertext editors to issue good pointers. That is one reason
why I loved the idea of publishers selling pointers as well as actual
material.

Not every writer would be open-minded, of course; even Fillmore at first
had feared hypertext. When O’Reilly and Associates put one of her papers
on the Web through _GNN_—spreading around her observations on electronic
publishing—she saw all kinds of links. By clicking on blue letters, for
example, readers would call up material about a founder of Internet.
Fillmore felt as if a Philistine had taken her beautiful bowl, her
self-contained piece of writing, and turned it into a colander. Some
writers might see a parallel in another way: Suppose the colander leaked
readers, who, seeing the links, dove off into another area of the Net,
and _never_ returned. Fillmore had adjusted to this possibility, and I
could, too. Just like Zonker Harris I was of the “May the best server
win!” mentality, except that I refused to confuse popularity with merit.
Books weren’t like sports servers.

From society’s viewpoint, another issue presented itself here. Both
Fillmore and I wondered about the damage that television and computers
might be doing to people’s attention spans. “Attention deficit disorder
seems to have arisen at the same time that computers have spread to the
home and office,” she said, “and I don’t think that’s an accident. How
many people age twelve and younger are capable of reading 300 pages of
sustained argument about anything?” Another worry arose, too, in my
mind. Like Frank Daniels, I realized that an entire generation of
children was spending more time gazing at computer and TV screens than
they devoted to books and traditional newspapers.

I felt that technology was destiny, that Washington and other
governments should promote computers that encouraged the receptive to
read e-books hour after hour. Too much of the new-style education, as
envisioned by many, would be task oriented—would be _training_ as much
as _education_ per se. That was fine for technical matters where, for
example, a future factory worker might want to learn the basics of
engine design. Hypertext was superb. The student could study a diagram
of a diesel engine, click on an individual part, and read and hear a
detailed explanation of its function. But I wanted technology that also
encouraged people to read and absorb whole books.

If book readers were too small a minority, then countries such as the
United States would be less democratic and more oligarchic, with the
elite all too able to manipulate the other citizens. Some social critics
such as Neil Postman demonized technology as a source of mindless
distractions for the masses. I, however, saw opportunity if we acted
soon enough before we lost more children to TV. That meant sharp
screens, smaller, lighter machines, and other advances—which would come
sooner or later, but which could be hastened by the coming of a focused
procurement program. Washington should assure the Valley a market for
the right hardware. It should also try harder to help schools absorb it,
so the machines wouldn’t just sit idle in closets.

A national digital library, not just a digital store leading to
commercial collections, was just as essential as better hardware. Today
a college student researching the effect of Shakespeare on popular
culture is able to find the Bard’s work at the school library. But what
about tracking down newer books that the library couldn’t afford to buy?
Also, only one student could read a paper copy at a time; suppose a
professor wanted many students to compare impressions of a novel,
especially one that was out of print and long gone from the bookstores?
People on the technical side could benefit even more than those in the
humanities. The best and most recent guides to Microsoft Word or
Windows, for example, didn’t come from educators; rather they came from
the private sector. The faster this knowledge could reach average
citizens, the easier it would be to upgrade the labor force.

A national digital library, moreover, would help many businesses market
their goods. A food company trying to sell a new line of rice, for
example, could instantly call up cookbooks of many ethnic groups and
find out the relationship between food and the cultures. In an era of
customized products, companies needed to learn quickly about niche
markets. That would be especially true as business globalized; corporate
planners had to keep on top of conditions in many countries.

So TeleRead-style libraries—which let people look through many kinds of
information, everything from books to UN reports—could make real
contributions in the United States and elsewhere. If nothing else,
governments needed to understand the possible efficiencies. Yes, public
and academic librarians would choose books. But innovative, private
firms would own the computer banks (well backed up) storing the books
and other material; many different contractors, always trying to outdo
each other’s technologies, could compete. Other efficiencies would
accrue. Pooling the public libraries of rich and poor citizens would
help everyone by increasing the variety of books available to all.

Big Brother needn’t run a national digital library. Subject-oriented
librarians in many cities might acquire material; in effect they would
be putting a public library system online, one that reflected the tastes
of, say, Lyons as well as Paris. How much more supple than the
overcentralized approach that the French now favored for their national
library! The elite librarians could still identify the books _they_ had
blessed, but the provincials could have their say as well; and, given
the variability of literary tastes over the ages, the latter in some
cases might prevail anyway.

What’s more, by gambling money up front to qualify for royalties from
TeleRead, writers and commercial publishers could bypass the librarians.
Book people such as Laura Fillmore could thrive under this approach. A
national library could offer e-books not only to citizens directly but
also to independent-minded entrepreneurs such as Fillmore, who could
charge for their custom links. I loved the idealism she showed in
suggesting that ASCII be free. It was a good model in many cases for
today. But I feared that as computers grew better for book reading—and
it would happen eventually, with or without a TeleRead program—free
ASCII would take away too many paying customers. And if ASCII books
weren’t free? Then, more than ever, piracy would occur regardless of
various legal and technological precautions. So the answer should be
free national digital libraries—well stocked and with fair pay for
writers and publishers—to reduce the temptation to bypass copy
protection. Use tracking to report dialup counts and pay originators of
material, but not for billing. _That_ was the way to take full advantage
of the technology and keep market incentives while promoting literacy.

Rich countries would be the first to start libraries of this kind. They
could safeguard their intellectual property by helping poorer countries
get books online if the latter agreed to honor copyright laws. The time
would come for national and international Electronic Peace Corps to make
this possible. EPCs could help upgrade Third World phone systems on site
and share knowledge via e-books, e-mail, two-way video, and otherwise.
To enforce global copyright law, we needed carrots as well as sticks.

What’s more, governments could protect books with technology far less
cumbersome than the $25 gadgets that the pay-per-read bookstore in
Virginia used. _Then_ e-text stood a chance. I thought of the old
merchant down South: Safes were useful, but only if the customers could
enjoy an air-conditioner—an easy-to-use digital library for all of a
country’s citizens.

National digital libraries, of course, could link up with each other and
form an official world library someday. But, given the many cultural
differences, that was impossible now. National libraries, then, were the
way to go—with opportunities for citizens in different countries to read
each other’s books when governments allowed this. I pitied the censors.
In an era of international computer networks, national libraries would
end up anyway as one big global library for citizens of open societies
and for the more resourceful people of countries such as Iran. Simply
put, national digital libraries would make it so much easier to market
or shop for books internationally. When a Swedish anarchist heard about
TeleRead, his big question wasn’t, “Isn’t this an opportunity for
cultural imperialism?” Instead it was, “Will I be able to read American
best-sellers as quickly as people there can?” Whatever the kind of
book—a Tom Clancy thriller or an anarchistic tract—TeleRead libraries
would allow easy global distribution.

In rich countries such as the United States and Sweden, the need for
national digital libraries would only grow with the introduction of
better televisions and video games, not to mention the distractions of
the Net itself—including virtual reality, at some point. Even in wealthy
nations, people had only so much disposable income. How much of it would
be left for online books? Mightn’t we use e-forms and digital libraries
to transfer resources from paperwork to knowledge? As much as I
applauded the good work that Frank Daniels was doing with the third
graders in Raleigh, I was a little put off by the online questionnaire
for adults and children using his BBS. It asked about favorite TV
programs, physical appearance, sports, and other activities, but a
simple question was missing—one that I felt certain would have been on
the list twenty years ago: “What are your favorite books?”

Spring 1995: An (Interim) Afterword

Whatever the medium—newspapers, books, or magazines—many Netfolks saw
the Internet as a path to diversity. That was partly why I liked seeing
_The News & Observer_ online with A. C. Snow et al. Maybe the Internet
could rescue locally owned newspapers before they all tumbled down the
maws of conglomerates. On May 17, 1995, however, _The NandO Times_, the
Webbed newspaper of the _N & O_, ran a story that I’d never wanted to
read. A chain was buying up the company. For perhaps the first time, a
Net daily reported on the sale of it and its pulped-wood siblings.

A color photo showed Frank Daniels III briefing his staff. What really
caught my eye, however, was a revelation that I saw later in the _New
York Times_: “Frank Daniels III said he was convinced that the paper
needed to find a larger parent in part to give the paper the resources
necessary to nurture those new electronic efforts.” More than a few of
us newspaper junkies had hoped that the new technology would help keep
the _N & O_ local. I recalled one reason why Daniels had not dumped his
_N & O_ stock in the 1980s in favor of an investment in an online
service. “The relationship between a newspaper and a community,” he had
said, “has such a richness and history that communities shouldn’t lose
that.” Now, however, after 101 years in the Daniels family, the _N & O_
and trimmings were going to a California chain for $373 million. The
buyer was McClatchy Newspapers Inc., the former employer of George
Schlukbier, the Daniels’s new-media guru.

No wicked corporate conspiracies existed here. The Danielses simply felt
comfortable with McClatchy, which not only shared the _N & O_’s still
basically liberal politics but also enjoyed a good reputation in the
newspaper business.

Run out of Sacramento, McClatchy Newspapers was a family-owned chain
with just twelve dailies. It allowed much more leeway to local editors
than many others did, and I might well have reacted just as the Daniels
family did when the McClatchy people came calling. The _N & O_ mustn’t
end up in the hands of some skinflint chain; McClatchy Newspapers could
be an excellent alternative.

Still, the sale did not delight me. The Net, after all, was supposed to
be good for small guys, including, presumably, family-owned enterprises.
Josephus Daniels had bought the _N & O_ at that bankruptcy auction in
1894, seen it through the Roaring Twenties, the stockmarket crash, and
the heyday of his friend FDR. He must have died thinking that the
Daniels name would forever grace the masthead. From a portrait in the
boardroom, he looked out at his progeny announcing the transaction. Just
why couldn’t all the computers and cables and videocams have helped
strengthen the family business, not force its sale?

I could see how the latter may have happened. The Daniels had had to
invest in both the printing press and the new med_ia_, with an emphasis
on the plural. A story on newsprint, an Internet audio, and a video
would cost more than just an old-fashioned version. Network-related
expenses of the _N & O_ may have been smaller than the investment in new
press, but they would only grow in the future. No-frills Web areas cost
next to nothing to set up. But net.papers with the very flashiest
graphics and full-motion video would need programmers and designers and
other specialists, not all of them cheap. At the same time the Daniels
wanted to cover their circulation area well, and that meant a big,
expensive staff of reporters, too.

Just as important, however, the _N & O_ faced strong competition for
advertisers and readers. Yes, the Net shrank distances and gave smaller
companies some new marketing opportunities. But as shown by Time
Warner’s giant electronic newsstand, it could also create some good
synergies for media conglomerates offering package deals to national
advertisers. In certain respects—hardly all—readers also benefited. I
could key in “Carly Simon,” for example, and see any stories that might
have appeared about her, not only in _Time_ but also in _Entertainment
Weekly_ or _People_. Frank Daniels could bring together wire service
news and offbeat items from technical publications and others. But in
the future he couldn’t match the brand appeal of corporations such as
Time Warner.

Daniels had a right to be proud of his technological accomplishments, of
course. But from now on, assuming that he stayed, as he apparently would
for the moment, he would be an employee rather than a member of the
owning family. Forget the Third Wave talk of Net saving us all from
conglomerates. We could all have our own home pages on the World Wide
Web, of course, and maybe put out little magazines; and IUMA-style
startups could always use the new technology to startle the Goliaths—and
in the end, exceptions notwithstanding, the Internet did foster
diversity. Clearly, though, it was far from an all-purpose savior for
the _N & O_s of the world. However powerful in North Carolina, the
Raleigh newspaper was hardly on an equal footing when it competed
against the very largest media organizations.

As if to underscore that point, eight huge newspaper publishers had
banded together earlier that spring to form New Century Network, a club
for the big boys on the Net. Some people wondered if the giants might
lose out in the end—readers wanted to tour the Web themselves, not just
confine themselves to material favored by newspaper coalitions. And
maybe New Century wouldn’t end up so exclusive after all. Also,
advertisers might prefer to sprinkle their cash around the Web rather
than focus it on newspaper chains—they could pay for links to their
pages from many sites without much ado. The natural economies of the Net
might yet win out over the business plans of the giants. Still, for the
moment, publishers such as Gannett and the Washington Post Company were
apparently setting the tone of New Century itself. The 185 New Century
papers claimed more than 23 million paying readers.

“New Century might raise antitrust questions,” wrote Rory O’Connor, a
reporter for the _San Jose Mercury News_, part of Knight-Ridder, a chain
in New Century. Peter Winter, interim chief executive of New Century,
said the publishers were “comfortable with our conformance to antitrust
statutes.”[4.31]

Antitrust was the talk of the newspaper and online industries. In early
June the U.S. Justice Department said it was studying the network that
Microsoft aimed to launch in August. Just by clicking on the proper icon
available through the Windows 95 operating system, people could join the
Microsoft Network. And some newspapers and other online services feared
that Microsoft could stifle the competition. In a year Windows might
sell 20-40 million copies; what if several million users clicked?

Newspapers worried increasingly about the Microsoft Network and other
online services. American Opinion Research of Princeton, N.J., found
that almost a fifth of the surveyed editors and publishers thought they
might lose more advertising to online services than to television.
Nearly three-quarters said the business was in good shape now. Just a
half felt the same would be true by the year 2005.[4.32]

The newspaper chains tried to fight back. Large papers now owned 11
percent of the shares in Netscape Communications, the wizards behind the
fastest and best browser on the Web. For the moment things seemed fine
for the public. Netscape came up with new wrinkles that other companies
didn’t offer, such as the ability for Web pages to sprout color
backgrounds without much fuss. But so far it was working with
standards-setting bodies rather than saying, “Hey, you guys, these
features will be _mine_ alone.” I just hoped that in the future Netscape
wouldn’t fashion its software to bind people to specific sources of news
from conglomerates such as Knight-Ridder. Perhaps half the people
cruising the Web were now using Netscape.

In a buying spree of its own, America Online purchased Internet fixtures
such as WAIS Inc., the software company. WAIS had made some of the best
publishing tools on the Net. America Online also bought the WebCrawler,
a first-rate index to the Web. The company acquired Global Net
Navigator, too, the wonderfully Netcentric magazine from O’Reilly and
Associates, a guardian of Net culture. Just like Frank Daniels III, Tim
O’Reilly alluded to the cost of online services. Explaining the sale, he
told a GNN mailing list that “in order to really do justice to the
information problem GNN was created to solve, GNN would have to be
scaled up beyond our ability to fund it on our own. With many large
players entering the Internet information services market, the best way
to keep our lead was to team up with one of them.”

The most dramatic—and, some critics might say, ominous—alliance may have
happened when MCI teamed up with Rupert Murdoch to form a new
partnership that could offer many kinds of material on the Net. It
committed as much as $2 billion toward his News Corporation.

MCI wasn’t just eager to be a pipeline for publishers and others—it
wanted to Originate Content. The phone company was already publishing
readers’ short stories electronically by way of Gramercy Press. Soon it
would release a trade paperback—yes, a book on pulped wood—from a
novelist writing under the name of a fictitious Gramercy author. But the
Murdoch alliance meant so much more. This global entrepreneur controlled
Harper-Collins through News Corps. Would his electronic books enjoy
global distribution advantages via MCI’s pipelines, compared to
offerings from smaller, less connected publishers?

Within the book business itself, the movement toward the Net was
accelerating as summer 1995 neared. More and more authors were online,
getting feedback from fans—just as the fledgling rockers of IUMA did. It
was a great morale booster, but only to a point. The novelist Nicholson
Baker, author of the _New Yorker_ article on electronic library
catalogues, complained that e-mail had “the problem of promptitude. You
have to answer within four days or you’re being rude. I like the
stateliness of paper, where you can take six months. You’re still being
unforgivably rude, but somehow it’s okay because other people have been
rude in this way before.”[4.33] Obscure writers, however, found the fan
mail from the Internet to be more helpful. In that way the Net was a
_friend_ of diversity.

Smaller publishers were also growing more comfortable with the Internet.
Bookport, a California-based service, let them post their books on the
World Wide Web for Netfolks to read page by page. Alas, a customer could
not obtain a whole e-book at once. The idea, of course, was to
discourage piracy. I disliked the idea of pay-per-read prevailing; the
library model would make books much more popular among the young and
actually _help_ good publishers. But the Bookport was well done with
oodles of great links to book-related sites on the Web. One of the first
titles was _Netiquette_, a guide to manners on the Internet; that was in
the community-minded spirit of the traditional Net.

Larger publishers, too, pushed ahead on the Web. Time Warner was selling
“Quick Reads.” It was a series of reference books, self-help guides, and
others that you could download in full and search for, say, the right
quote from a famous business executive (_Bartlett’s Book of Business
Quotations_) or the appropriate recipe (the _Cooking Library_). I could
understand Time Warner’s fondness here for reference books. Most readers
didn’t want to gawk at electronic novels hour after hour. The big
question, in cases of tech-savvy conglomerates like Time Warner, was not
whether the publishers were ready. It was whether the _public_ was;
whether enough people would end up soon enough with the proper hardware
for reading books in bed or on the sofa.

That, of course, was where TeleRead came in. Whatever their sizes,
publishers needed to hook the nonelite in this videocentric era before
they gave up on the written word.

                  *       *       *       *       *

The above is not to suggest that text is the only way to communicate
knowledge over the Net. The right graphics certainly can as well. One of
the most intriguing examples of the potential here is a remarkable
endeavor—the Visible Human Project—in which, so to speak, a murder lives
on forever in cyberspace to the benefit of medical education and cancer
research. I’ll discuss this in the next chapter.




                                CHAPTER
                                  FIVE

    Wired Knowledge:
    When They Let a
    Murderer Loose
    on the Internet


Paul Jernigan was a tattooed ex-mechanic just under six feet tall and
weighing 200 pounds. He had been a drug addict and a chronic drunk, but
nearly all his organs still looked in textbook shape by the standards of
gross anatomy—a stroke of luck that would later help him win him a
macabre competition. Jernigan had fatally stabbed and shot a
seventy-five-year-old watchman after stealing a radio and a microwave
oven. More than a decade had passed. So had his hopes for a successful
appeal to the courts.

Lying on a gurney in a Texas deathhouse—his arms outstretched, as if in
a crucifixion—Paul Jernigan just gawked upward as his brother watched.
No last words came before the poison flowed into Jernigan’s veins.

Jernigan gave himself to science. A not-so-loquacious sister told me
this was to spare the family the cost of burial. “It was like, matter of
fact,” his last attorney said of the donation. “It was a gift. He wasn’t
going to laud himself, pat himself on the back. We didn’t send an
embossed announcement that ‘Paul Jernigan has donated his body to
science and this is his ticket to redemption.’”[5.1] A former cellmate
offered his own twist. Supposedly, Jernigan wanted his family to be able
to sell his life story for a true-crime book. The donation just might
make the planet care more about him in death than in life.

Within a year of the execution, in fact, I was reading clips about Paul
Jernigan from the _London Times_, _Jerusalem Post_, _New York Times_,
_Washington Post_, _Los Angeles Times_, and the _Boston Globe_. My
favorite lead came out in a British paper called _The Independent_: “A
killer was yesterday let loose on the Internet computer network.” I
wondered how he’d respond to flaming. The new Jernigan lived on as a
digital atlas of the human body, a few steaklike cross sections of which
I could dial up on the World Wide Web.

The Visible Human Project had come out of the National Library of
Medicine in a Maryland suburb near Washington, D.C. It was one of the
most spectacular examples of the Net’s potential for spreading
knowledge, the topic of this chapter.

Researchers had cut Jernigan into four blocks, frozen him in a blue gel,
ground him down millimeter by millimeter, digitally photographed the
1,878 cross sections that emerged, scanned these slices[5.2] into a
computer, put them on magnetic tape, and then on the Internet. Now the
cadaver would be grist for medical educators and cancer researchers and
perhaps even the designers of a “Fantastic Voyage”-style game. Players
might explore the human body from the inside, just as Isaac Asimov’s
characters did in his novel. The government itself was spending $1.4
million on the project; expected commercial payoffs could reach the tens
of millions and maybe more. Research and education, however, would be
paramount here.

The Visible Human Project is but one of thousands of uses that academics
and researchers have found for the Internet. The Net is why many
scientific luminaries were quick to slap the “fraud” label on efforts to
create energy through cold fusion. Skeptics throughout the world could
compare notes. If Paris couldn’t replicate an experiment, then Boston
would know within hours. Working in the other direction, fusion
stalwarts have used the Internet to swap data and maintain the faith.
Cyberspace is to knowledge what beehives are to honey.

Already the Net teems with thousands of mailing lists devoted to the
most arcane disciplines, not just to the mainstream ones. Many
scientists and other researchers envision the Net as a substitute for
paper-style academic journals, subscriptions to some of which can cost
as much as a Ford Escort. Stevan Harnad has caught the imaginations of
many academics with “A Subversive Proposal” for scholars to publish
their finished works formally on the Net without offering them to
academic publishers. He puts out a vigilantly edited, psychology-related
magazine with a circulation of tens of thousand on the Internet; he sees
no reason for the Net just to be a repository for pre-publication
papers. In his opinion, academics could use such opportunities to enjoy
greater bargaining power with existing publishers.

Yet another glory of the Internet is that it serves as a bridge between
experts and nonexperts, as well as one between authorities in many
academic disciplines. A dean of a law school, for example, can sign up
for mailing lists on electronic serials to learn more about the
technology that is fueling the drive for copyright reform.

From Day One, the Internet was a creature of the elite research
establishment, but knowledge-related uses have steadily grown more
egalitarian—starting with the brightest students in elementary and high
schools, then moving on to average children, and even to problem kids.

To dispose of a major issue, No, the Net shouldn’t replace teachers. I
couldn’t agree more with Cliff Stoll when he rants against lax standards
and mindless technocratic schemes. Well-trained teachers can provide
inspiration and guidance to help children explore networks on their own.
The last thing we need is to turn the educational reaches of the Net
into one big flash card. What the Net can do is prepare children to deal
with source material, with actual papers written by researchers, as
opposed to pabulum in textbooks.

Correctly, Stoll criticizes some educators for teaching astronomy
without children studying the actual sky; computer programs should only
supplement such activities, not replace them. But shouldn’t he apply the
same “real thing” logic to Web-distributed source material and applaud
students’ easier access to it? Only the brightest children will benefit
from a complicated mathematical treatise. But surely even an average
student could take advantage of a historian’s paper on a nearby Civil
War battle. If anything, teachers could use the Web and other areas of
the Net to demand _more_ research from students. Just why must Stoll
compare the Net to a fun but dumb educational film? Is a Web version of
the _Odyssey_ to be confused with some educational Looney Tunes?

Intriguingly, Web technology makes it possible for students to produce
information, not just soak it up. In Fairfax County, Virginia, students
at Thomas Jefferson, a high school for the gifted, are posting their
“pages” on the World Wide Web. I can remember when college applicants
submitted tape recordings of their music. Now they can also give M.I.T.
or Caltech the addresses of their Web pages and demonstrate, in the most
direct way, their familiarity with networking. They can post their
papers and point to other people’s pages that interest them.

Also, at Jefferson and countless other schools, students can
electronically send their classmates to knowledge-rich sites on the Web.
Clicking on “NASA” in blue letters within Bob’s area, Jill can see what
the space program is doing. Then she can return, click on other blue
letters, and check out his tip to visit a history-related site
discussing the Sputnik and Vanguard days. Via a project called
MendelWeb, Ellen can read the famous treatise of Gregor Mendel, the
geneticist, and retrieve other scientists’ opinions; then she might
write her own paper and post it on the Web for classmates and even for
students elsewhere.

Clearly the value of the Net, for students and researchers alike, isn’t
just in the information per se—it’s also in the ease of sharing it.
Teachers can point to common Web resources (such as MendelWeb) from Web
pages where they add their own comment, or even their own study guides.
They can also link to other guides.

Some Web sites even offer electronic forms with questions to which
students can respond—in either a multiple choice or an essay format.
Andy Carvin, a specialist in educational technology with the Corporation
for Public Broadcasting, praises the World Wide Web as “an excellent
tool in which to design online curricula.” Understandably, even
elementary schools are getting on the Web with their own areas.

Other good things are happening. By way of a project called Big Sky
Telegraph, Native Americans in Montana have been pen pals with children
in the former Soviet Union. What better way to stir up an interest in
writing, politics, and geography at the same time? Significantly, in
Montana and other places, many schools are not on the Net directly.
Instead, schools use affordable bulletin board systems—their own or
perhaps those operated by hobbyists—which can relay Net-originated
material. If need be, such systems can run on ancient computers of the
kind found at garage sales; some messages may be delayed for days, but
that’s better than no connection at all. Within the BBS world, moreover,
nets even exist especially for education. Consider K12Net, which
includes at least “three dozen conferences specifically related to K-12
curriculum” and reaches some sixty school-associated systems in New
Zealand alone. More and more, however, lucky schools are hooking into
the Internet directly or at least arranging for teachers and students to
get accounts elsewhere.

As a ninth grader at Poolesville Middle Senior High School, in
Poolesville, Maryland, Chris Gazunis used the Net to study catastrophes
such as earthquakes, hurricanes, and oil spills. “We didn’t just look at
a textbook diagram of what caused an earthquake and the casualty number
associated with it,” he recalled. “We used the networks to learn what
happened to the people’s lives and homes. Instead of just being given a
set of directions and material that would result in an earthquake
resistant building, we designed and tested them ourselves.”[5.3]

Randy Hammer, a high schooler at Timberline High School in Lacey,
Washington, who is blind “with two glass eyes,” once had to have sighted
people read the newspaper to him. No longer. Via network connections, he
can enjoy the _Washington Post_, the _Moscow News_, and science-oriented
publications—thanks to a gadget that reads aloud to him the words on his
screen. “It’s hard now,” he wrote, “to remember how I lived without this
wealth of materials and information at my fingertips.”[5.4] That’s what
happens when the hardware is around.

Even in a wealthy place like the United States, however, society so far
has been stingy toward high tech in public schools. The ratio between
students and computers is something like 16 to 1. Some 75 percent of
American schools have computers capable of getting on the Net, but the
children can’t all use them at once. What’s more, just 35 percent of
public schools have Internet hookups in classrooms, media centers, or
computer labs. Only 3 percent of the classrooms themselves are wired in,
according to a survey from the U.S. Department of Education.

We’re talking almost Third World here. “It’s amazing to me how people
outside of education have no idea how teachers still have to line up
outside the teachers’ lounge to use the telephone,” says a senior
analyst at the Congressional Office of Technology Assessment.[5.5]

In the end, as I see it, the real solution is a TeleRead-style program
of the kind described in the previous chapter. It would connect the
students to the nets from home, reduce the future communications costs
of the schools somewhat, and allow students to explore computer networks
at leisure rather than just during the school day. A few small steps are
already being taken in this general direction. The state of Maryland has
granted limited—but free—Internet privileges to school children and
other residents. Without leaving home, they can dial up material ranging
from weather reports, to academic papers, to Shakespearean poetry.
Joseph Peightel, a cable splicer with Bell Atlantic, says that the
Sailor program is just the ticket for his ten-year-old daughter, whose
hunger for books outstrips the family budget. While the Peightels can’t
retrieve the latest best-sellers, they at least can enjoy Project
Gutenberg-style material in the public domain. The Maryland program
helping the Peightels is not TeleRead, and it comes with problems and
inefficiencies, but it may be as close as any state effort to the
nirvana envisioned by Al Gore, in which all children could dial up the
Library of Congress.

Needless to say, I bristle when Cliff Stoll glosses over the reasons why
the Net can’t provide easy answers to questions such as “What political
compromises caused Bismarck to become the capital of North Dakota?” or
“Why isn’t Kyoto the capital of today’s Japan?” or “What’s the history
of the Ruhr Valley, and what are the implications of its new Eastern
European competition?” Of course. Worried about piracy, publishers have
understandably kept their textbooks off the Net. The last laugh,
however, just may be on the more zealous of the copyright interests.
Right now Stoll couldn’t be more correct about the need for more and
better books on the Net; but as shown by, say, MendelWeb, the academic
community is doing plenty on its own. And if this keeps up, the demand
for copyrighted, commercial books, the kind that feed me, my editors,
and yes, my publishers, too, could suffer. Far better to have a national
digital library with privately originated books available from the very
start.

Ahead I’ll examine more closely some scientific and educational uses of
the Net. Selections—yes, the print kind, not the Jernigan variety—will
appear on:

• The “hows,” the positives, and the negatives of the Visible Human
  Project—it stands out for reasons beyond the drama. The Clinton
  administration has encouraged high-bandwidth, scientific users of the
  Net. The original Visible Man requires sixteen gigabytes of
  storage—enough space to hold fifty _Encyclopaedia Britannica_s. Some
  say this isn’t the best use of Net resources. I disagree, however, and
  I’ll tell why. Along the way I’ll pass on information about the
  Internet’s Visible Man before he became so visible.

• High school use of the Internet. The United States is hardly the only
  nation with thousands of children in cyberspace—countries ranging from
  Canada to Singapore are putting students online, directly or
  indirectly. Significantly, computers and networks can help students
  outside the elite. Some proof of this comes from Nova Scotia, where,
  for several years, a high school has been using the Internet to
  benefit some “at-risk” students. I’ll tell you about the Internet
  success that a Canadian teacher named Jeff Doran has enjoyed with
  leather-jacketed teenagers. Many are racing into the computer lab and,
  let’s hope, away from fates such as Paul Jernigan’s. The Internet
  project at Park View Education Centre is far from an unqualified
  triumph—many Park View teachers still fear the technology—but patterns
  there suggest a vast potential for educational uses of the Net if
  schools will modernize their curricula.

The Visible Man

The doctor, a Scottish-accented man in his fifties or sixties, had
collected a wall full of diplomas and plaques. Perhaps that’s why he
felt entitled to give only the sketchiest of explanations when he told a
Midwestern friend of mine that she might need heart surgery to avoid a
possible stroke. Karen* would be in the hospital just a day or so. But
during this time a surgeon would insert a catheter up her groin and go
on to kill off selected heart cells. With luck, the operation would end
her atrial fibrillation. It had made her heart throb as quickly as 200
beats a minute on occasion and had sent her to the emergency room.

Karen pressed for details about the recommended operation. “Ma’am,” Dr.
S. said in a peremptory burr, “this is too technical.”

It was Valentine’s Day and Karen and her husband would rather have been
thinking about hearts in that way alone. But she wanted to know all.
“Ma’am, I’ll draw you a picture,” Dr. S. said a bit grudgingly. The
doctor sketched a crude heart that might as well have been on a greeting
card. Hastily drawn lines showed how electric impulses were traveling
through Karen’s heart with an extra path. The operation would cut off
the surplus wiring, so to speak.

Well, this was a start. But Karen still felt ignorant, and it was _her_
body into which the catheter would go. And so it is with many patients,
not all, but many. Even good doctors don’t always tell enough.

The Visible Human Project, however, would make it easier for Karen to
learn more. Dr. S. could have shown Karen a computer image of an actual
human heart and have pointed to the exact areas that the surgeon would
kill off. Karen would have picked up a better appreciation of the
complexities of the proposed operation. At the same time, Dr. S. could
also have juggled around computer images to show the increased risk of
clotting that would result if she _failed_ to have the operation. Karen
would have emerged better informed and more confident—or less, whatever
the facts justified. Someday she might even be able to dial up on the
Internet an animated, perfectly detailed series of pictures of the
operation.

That was what the Visible Human Project would mean. What’s more, patient
education was just one of many uses; the right technology could
revolutionize the training of doctors and advance medical research.

As far back as the 1980s, such ideas intrigued Michael Ackerman, a Ph.D.
in biomedical engineering who worked for the National Library of
Medicine, part of the National Institutes of Health. He heard of a
project at the University of Washington that was digitizing the human
brain, although not the entire body. Researchers at other schools hoped
to do the same with other organs. But they were less keen on collecting
images and other data than on using them, so why duplicate each other?
Like the Internet itself, then, just one digitized corpse could help
many researchers at once.

In North Carolina a marketing executive with a drug company was dreaming
of a human atlas on a computer screen. Why should medical students have
to make do with fold-out drawings in anatomy guides? Michael Du Toit,
Vice President of marketing for Glaxo Inc., passed the idea on to a
small company called Butler Communications, which checked out the
technology. Glaxo had three goals. First, it wanted to create the basic
images. Second, it wanted viewers to be able to wander through the body;
ideally they could move the body for the best view, spin it, travel
through it. And third, it wanted researchers to be able to give the
lungs cancer, clog the arteries to the heart, and demonstrate the
effects of drugs. But computers weren’t ready. “The hype versus the
deliverable,” Robert Butler told me, “was miles and miles apart.” To
meet Glaxo’s specs—to show the body by way of artistic recreations and
virtual reality—might cost as much as $100 million.

Imagine the excitement that Du Toit and Butler must have felt on
learning that academic and government researchers were finally coming up
with the means for this to happen at a fraction of the expense. The Feds
put out a request for proposals for the dissection job, and the crew at
the University of Colorado made the final cut. Still unanswered was the
question of whose corpse would end up on the Internet. The contest
judges allowed a bit more leeway than did the people choosing Miss
America and Mr. Universe.

The ideal candidate for Visibility could be anywhere from maybe thirty
to sixty years of age and be a bit thin or pudgy, albeit not exceedingly
so. Height mustn’t go too far beyond the norms for male and female.
Above all, the innards of the body had to be photogenic from an
anatomical perspective. That weeded out anyone worn down by cancer or
similar disease, not to mention any victims of automobile accidents or
knifings.

A little unfairly, this contest had geographical limits. Texas,
Maryland, and Colorado were the states with subcontracts to provide the
body. I could understand Maryland and Colorado, but Texas? I wondered if
the reason would be the fondness of the people down there for capital
punishment. No longer did bodies have to roast in electric chairs. Texas
helpfully killed its murderers with lethal injections. So, in this
competition, Paul Jernigan was a strong contender from the beginning.

Murder is an act of the will no matter how poor or Hitlerian our parents
are, or what genes shape us and our brains. But if Fate sent anyone to
the deathhouse gurney and to Visible Manhood, it was Paul Jernigan. He
lived out an updated Dreiser novel.

His full legal name was Joseph Paul Jernigan, and he was born in Geneva,
Illinois, on January 31, 1954, the youngest of Earl Jernigan’s six
children. The boy suffered from asthma and almost died of it. He and his
brothers and sisters typically owned just one pair of jeans each. Their
mother eked it out in a chicken-processing plant, as a clerk at
Montgomery Wards, and at other low-paying jobs, and they lived in public
housing. She married a truck driver who, like Earl, was a strict
disciplinarian toward the children. Later she suffered a stroke.
Afflicted with a learning disorder, Paul flunked a grade at school and
dropped out two years before graduating. He was a drunk and eventually
was doing a pharmacy’s worth of drugs, from Quaaludes to horse
tranquilizers.

The Army trained Paul Jernigan as a mechanic, sent him to Germany, then
tossed him out as unsalvageable. Perhaps recognizing the cruel matrix
that shaped Jernigan, it gave him a general discharge (a “no comment” in
effect) rather than a dishonorable one. A shrink later found Jernigan to
be a passive-aggressive man who was sometimes TNT-volatile. In the years
after the military Jernigan kept a cooler of ice and beer in his
automobile; a typical paycheck went for pot, cheeseburgers, and enough
octane for himself and the car.

Paradoxically, though, friends trusted Paul Jernigan with their
children. Jernigan was the perfect baby-sitter who enjoyed romping
around with his charges. He married for a stretch and loved his
stepchildren.

But he failed at marriage just as he had failed in school and in the
Army.

Jernigan bungled at burglary, too. He was already a two-time loser in
1981 when he and a pal named Roy Lamb were driving down the road in
Corsicana, Texas, a small, howdy-neighbor kind of town south of Dallas
on Interstate 45. Emboldened by a night of booze and pot, the two
decided to rob Edward Hale’s house. They began stuffing their loot into
a pillow case when Hale surprised them. Lamb ran out. Jernigan beat Hale
over the head with an ashtray, hoping to kill off the witness. Hale
stubbornly survived. Then Jernigan stabbed him with a rusty, dull-bladed
meat knife, which just bent on Hale’s chest. And so he took a shotgun
and fired until the watchman was dead. Edward Hale did not die
painlessly.

After the murder, Jernigan went to Houston to try to straighten out his
life. He was in a halfway house when arrested.

Some would say Jernigan needn’t have wound up on the gurney; the law
prevented the courts from accepting an accomplice’s testimony. Mark
Ticer, his last attorney, believes that Jernigan may have felt so
contrite that he wanted to die. Ticer grew truly fond of his client. In
character, Jernigan would constantly inquire about the lawyer’s
two-year-old and remember birthdays.

Jernigan gave Ticer’s wife, Cecily, some earrings made from gold bought
with his military pension, and he crafted a wishing-well bucket for
Ticer. Ticer was as trusting of the murderer as Jernigan’s friends had
been; he would have trusted him with his own young daughter. Even on
death row Jernigan would write to the stepchildren from his failed
marriage.

Smoking a hand-rolled cigarette and sipping a Pepsi, he would discuss
legal strategy with Ticer until finally there wasn’t quite so much to be
strategic about.

“Paul,” Ticer more or less said, “things are not going well. I guess I
have to talk about your burial arrangements if they’re going to execute
you. I know your family doesn’t have a lot of money.” And it was there
in the Ellis prison in Huntsville that Ticer learned of The Gift.
Neither knew Jernigan would eventually become the Visible Man.

Mark Ticer tried for a stay of execution up to the last minute. Aware of
Ticer’s devotion to him, Jernigan asked his lawyer not to witness his
last minutes. Death was almost instant. Paul Jernigan died much more
smoothly than he had lived.

The state anatomical board, a subcontractor of the University of
Colorado, took it from there. Jernigan got one and a half gallons of 1
percent formalin. That was a light touch. Often cadavers are embalmed
with ten gallons of a stronger preservative, and they sit and pickle for
a year, so that when medical students cut them up all the tissues are
gray. But the idea here, in case Jernigan won the Visible Man honors,
was to keep his tissue looking nice and bright like prime meat; the
students would be able to enjoy a better, more realistic view.

Writing this chapter, I pondered the use of the state anatomical board
as a cadaver procurer. Thank God the board was separate from the court
system. Given the rage for businesslike government, I could just imagine
some of the wilder politicians setting up an execution quota to work
toward a balanced state budget. But the real reason for the use of
Jernigan’s corpse was more prosaic. Texas had one of the best
cadaver-donation programs in the country, and of some 2,000 bodies that
year, his just happened to show up at the right time and in the right
condition.

A Learjet flew Jernigan from Texas to Colorado. Awaiting him were the
masterminds of the dissection effort at the University of Colorado
Health Sciences Center in Denver. Victor Spitzer specialized in
radiology and cellular and structural biology; David Whitlock was a
professor of cellular and structural biology. The people working most on
Jernigan would be the research assistants in the dissection room, which,
day to day, was overseen by Tim Butzer, thirty, and his wife, Martha
Pelster, a bright, curly-haired woman of twenty-five who would later
apply for medical school. Helen Pelster, another assistant, was the
sister of Martha Pelster.[5.6] The whole scenario—the family
connection—begged for embellishment from Stephen King or Robin Cook.

I asked Martha Pelster if her work haunted her at night. “I kind of keep
it on a pretty even level,” she said. “I don’t have too much trouble
with it.”[5.7] She said Butzer felt the same.

Had Jernigan inspired much after-hours talk with her husband?

“If there was a problem that needed to be worked out.”

But did Pelster and Butzer reflect on the Visible Man’s past in relation
to what was happening now?

“Not too much. Getting emotionally involved with something like that—you
don’t want to discuss it. It isn’t relevant to what we’re doing.”

Inquiring about the university’s most famous cadaver, I learned that
Jernigan had come with at least two tattoos on his chest area; they
looked vaguely like dragons. His build and muscles were impressive. The
lab had to modify some of the machinery to handle Jernigan. He showed up
with just one testicle, which, I learned elsewhere, was the aftermath of
painful surgery from his military days. I also heard that another
operation had left him without an appendix. Students and researchers
seeking to unravel the mysteries of appendixdom would just have to turn
elsewhere. As a taxpayer, however, I didn’t feel cheated. This was the
States, not Bangladesh; did that many Americans die without any remnants
of surgery? Jernigan’s cadaver stood head and shoulders above a rival, a
woman who was a chronic alcoholic with visible damage to her liver. In
the hierarchy of the dissection room livers must have counted more than
appendixes.

Before the millimeter-by-millimeter grinding, the scientists treated
Jernigan to magnetic resonance imaging (MRI, mixing radio waves and
magnetic fields) and computer-aided tomography (CAT or CT, which is like
topography except that it’s on the innards of the human body). MRI picks
up soft tissue. CAT scans are good for hard tissue, and for the
differences between it and soft tissue. The researchers CT’ed Jernigan
both before and after he was frozen, and these scans had to correspond
with the alignment of the digitized photographs. Imagine the precision
required here.

Preparing to slice the icy cadaver into four blocks for convenient
grinding, the lab crew sharpened up on a less exalted cadaver. Vertebrae
were a problem. “This saw would curve,” Pelster said, “so you wouldn’t
have a perfect perpendicular flat cut. It would have a curve to it. So
we took the cadaver back to the CT scanner and found the level where we
could make a cut.” In the end there were three cuts and four sections of
Jernigan—head and torso, abdomen and pelvis just down to the thighs, the
rest of the thighs and the knees, and just below the knees to the feet.
The frozen pieces went into an aluminum mold, one at a time. And then
the researchers poured a blue gel around them (the same blue you’ll see
on the edges of the cross sections if you dial them up on the World Wide
Web). The result was four chunks of ice, each approximately 20 by 20 by
15 inches.

The grinding area was the next stop. Plexiglass enclosed it. That was a
must. Pieces of cadaver would fly everywhere as science turned Paul
Jernigan into dust with a spinning, carbide-tipped blade. “You’d think
we’d have trouble sectioning bone,” Pelster said, “but that’s not been
the case. Bone always cuts very clean. But sometimes we have a lot of
trouble with the tendons. The tendons are such that they don’t want to
shear off cleanly, and so a lot of time we did hand scalpel work on each
slice. So the slices might take ten minutes each instead of four minutes
each.” Actually the time varied. “Ninety slices were the most we cut on
any one day, and we averaged sixty. Sometimes it was ten a day. It was
about four months of sectioning.”

“Were you worried about damaging the goods?” I asked.

“Definitely. We just did the best we could.”

“Any near misses?”

“There were definitely a few. We never were to the point where we
torpedoed the whole project. It would be more a possibility of losing a
slice. We never came close to botching the whole thing. You look back
and you see a little dot of ice here or there, things like that. You do
the best you can. But I think it turned out well.”

All along, of course, cameras and lights were clicking and flashing
away. The slices went into a black-walled, reflection-proof chamber for
photographing by one digital camera and two with film. A table held the
cameras. It turned to give each a view of the cross sections from the
same angle. The results went into a Macintosh Quadra 840AV with 128
megabytes of random access memory and 2 gigabytes of hard disk space. It
was, in other words, many times more powerful and could store at least
several times more than the average personal computer. As with the
grinding, problems sometimes arose. “You think computers are so
precise,” Martha Pelster said, “but they’re not. Things are always going
wrong.” Typically working with her and Tim were such people as the man
who kept the grinding machine running, a camera expert, and a computer
expert (Helen Pelster, Martha’s sister), who would transfer the
digitized Jernigan to tape and CD-ROM. Come the end of a hard day of
photography, the lab crew collected everything and put it back in the
freezer. “And then when we were finished doing this,” Pelster said, “we
had many bags of things that needed to go be cremated.” The dust went to
a contractor for incineration.

Digitized photos and CAT and MRI images from Jernigan went to National
Library of Medicine in Maryland and to the Scientific Computing Division
at the National Center for Atmospheric Research in Boulder, Colorado.
The latter worked with a Cray Y-MP/8 supercomputer and Silicon Graphics
workstations to study the results. A headline on the World Wide Web
summed up the magnitude of the computational task: “The Visible Human
Project: Can It Bring a Supercomputer to Its Knees?” A machine with the
power of the Cray could take the 1,878 cross sections, stack them like
slices of an upright bread loaf, and create electronic bones or hearts
or brains that looked as if they had never been taken apart in the first
place.

By fall 1994, Michael Ackerman at the National Library of Medicine was
ready to tell the world about the electronic Jernigan and to have his
images posted on the Net by way of the weather forecaster’s facilities.
“We hold this out as an example of the future of health care,” Ackerman
said. He predicted that the study of medicine would become increasingly
visual. No one talked then of a murderer, and so the first stories on
the wire services blandly mentioned an anonymous thirty-nine-year-old
donor from Texas who had died of a drug overdose.

Learning that a digitized corpse would go on the Internet, not everyone
greeted the news with unalloyed praise. Some reviled this as a waste of
Net resources. Why not use CD-ROMs to distribute the information? To an
extent I could see their arguments. The Library was releasing sixteen
gigabytes of images at the start, and even someone with a deluxe Net
connection could spend a week or so downloading it. Critics believed
that this squandered bandwidth, that it was a bit like cruising down a
narrow country road with an overgrown tour bus and fifty cars honking at
it from behind. The strain on the Internet was far from that bad. But
even by Net standards this was indeed a behemoth, and much more
importantly, the bandwidth defenders worried about the precedent being
set here. Sixteen gigabytes of images was equivalent to 8 billion pages
of double-spaced typing. Individual e-mail messages commonly took up
only a page or two.

Even so, the Visible Man had his friends out there in cyberspace.
Anxious to beat rivals to the data, one company kept its modems pumping
away for a week until it had received all of Jernigan. It didn’t want to
wait weeks or months for tapes. Thanks to the Net, many people
throughout the world could receive Jernigan at the same time. In the
first few months of the release, more than 900 companies, schools, and
people wrote Ackerman about licenses giving them permission to use the
data in experiments and products. Some 100 actually followed
through—everyone from pharmaceutical firms to a young artist who,
according to Ackerman, assured him that she would make tasteful use of
the images.

Luckily from a bandwidth perspective, you didn’t have to download all of
Jernigan. Each slice was a mere seven megabytes in a spatial resolution
of 2,048 by 1,216 pixels (several times sharper than that of a typical
personal computer). A maker of software for ophthalmologists could pull
down only the images dealing with the eye and related brain areas. Those
aiming for the podiatry market could focus on the feet and ankles.
What’s more, even without a license, ordinary Net users could dial up
Jernigan Lite, so to speak, from the World Wide Web.

Coming over the Net eventually would be more than just the raw,
unprocessed images. Refined versions—for example, animated Jernigans,
rotating in 3-D, or even virtual reality versions—could go anywhere in
the world. And when they did, researchers and students would be wanting
their own pet views. CD-ROMs just didn’t store enough data to anticipate
all the possibilities. Typically they could hold maybe 650 megabytes of
data. Even extended, the storage would offer a fraction of what could be
available via high-speed connections to sites from Paris to Melbourne.

Jernigan, you might say, was more than just the material for a medical
experiment. He was also a focus of a research project to develop special
formats for libraries of visual information on the Net. Eventually
people would be able to download not just images but also the “objects”
that made up the images.

“These objects will have knowledge in them,” Michael Ackerman said, “so
they know how they relate to each other and the rest of the scheme. Say
you ask for the heart. What you get of course is the not a picture of
the heart but the objects that made up the heart that your software has
now rendered as the heart. If you point to something on the heart, it
can open up because it’s made up of these objects. And if you point to
something on the margin of the heart and say “What is attached here?”
that object on the margin knows what its nearest neighbor is even though
it’s not in the picture. And it knows to go back to the database and
bring up what’s attached to it.”

Such an approach might even take advantage of Web-style technology to
link together libraries at a number of locations. So you might smoothly
travel from, say, a processed image of a blood vessel done up at School
X to an animated image of a heart as tweaked by Company Y.

Those uses would increase the load on the Internet, of course. But
ultimately the principle of the expanding pipeline might work to the
benefit of all. That is, the heavier the traffic on the Net, the heftier
the connections would be built. So in the end, everything would be
cheaper—from image transmissions to sending one-page notes by electronic
mail. The challenge, of course, was for this to happen without the costs
of ordinary Net users being driven up by the workload that the image
libraries and similar endeavors would bring about. That’s where TeleRead
might come in. It could systematically promote the mass use of
electronic forms for tax documents, business transactions, and other
purposes. And indirectly the money saved on paperwork could go not only
toward a national library but also to help upgrade the present Internet
for researchers and the world at large.

Right now people tended to see the applications of the Net in terms of
one use versus another—in terms of money for low-cost networks for
consumer education versus high-bandwidth connections of the kind that
Ackerman wanted. With a TeleRead-style approach and enough imagination,
however, we could take full advantage of the economies of the
technology. And so although we would not end the clashes between Net
users with different priorities, we could at least reduce them.

Several other cost-related questions arose beyond those of the expense
of the network connections. I wondered how much patients would be
charged to see a picture of the innards of Jernigan or a Visible Woman.
Robert Butler doubted that his client, Glaxo, was ready to say. However,
he left me with the impression that this probably would not be pay per
view. Glaxo had its own reasons for going ahead—for example, showing
doctors the effects of its pharmaceuticals on the body. So, no, he said,
this was not a plot to gouge the public with peep shows.

A related issue, arising from the involvement of drug companies, was the
question of proprietary information. While the images were on the
Internet for all to see, this project was not entirely in the spirit of
the Net’s openness. Butler, for example, might have feared that I was
working for a rival corporation, and he waited several weeks to return
my calls. I could understand his reasons. Still, I was startled to learn
that Ackerman at the National Institutes of Health would not even
release to me a list of the companies that had licensed the use of the
images. Nor had NIH organized a newsgroup or a mailing list. Surely all
the hundreds of licensees would have common problems, common
opportunities, that they could discuss without imperiling each other’s
projects.

Yet another question went back to one of the main reasons given for the
project. Could medical students really learn by hooking into the Net and
dialing up the images from the Visible Man? David Dean should have been
a complete booster of this endeavor. He was, after all, a Ph.D. who
worked in medical imaging and taught anatomy at Case Western Reserve
University. And yet he told me, “I feel you can’t replicate the
experience in the anatomy lab. Students will have no time for this
stuff. They’re totally overwhelmed. They can see the same structures
again and again in different bodies.”

At the University of North Carolina in Chapel Hill, Gerry Oxford,
professor of physiology, said that seeing organs in three dimensions
wasn’t the same as _feeling_ them. “Physicians in training need a
visceral appreciation of the fact that they will have responsibility for
the human body.” Even a believer in the project, Marc Nelson, assistant
dean of medical education at the Stanford University School of Medicine
in Palo Alto, worried that electronic anatomy could lessen contacts
between students and teachers.[5.8]

Real bodies, however, cost universities $600 each—assuming they could
get them in the first place. And students would not have eyeballs,
hearts, hands, and livers to themselves.

Of all the boosters of the project, Martha Pelster may have been the
most persuasive. She worked as a lab assistant, had cut up dozens of
bodies, and now was headed to medical school. “When you look at this
cadaver,” Pelster said of the digitized Jernigan, “everything is still
in its orientation. When you go in and dissect, you take a lot of stuff
out. If you cut something wrong or cut through something and toss the
object into the reject bin, you’ve lost it. But with this visible male,
you can go back in again. You can see what happened before your lab
partner went in there and messed up your cadaver. This cross-sectional
anatomy is going to be the be-all and end-all. A book can’t have this
many cross sections, this good.”

Just as important, no one in the project, from Ackerman to Pelster, was
touting electronic cadavers as a complete substitute for the real ones
that the medical students studied. The digitized versions would simply
augment the real cadavers, the ones that you couldn’t reboot if you cut
them the wrong way. In the new era, medical schools could even require
students to put the human body together, not just take it apart.

Cadavers in cyberspace would offer yet another advantage: even
schoolchildren could study them. People for the Ethical Treatment of
Animals and some rock-n-roll musicians such as Pearl Jam were asking
schools to “cut out dissection” and use computer imaging or model frogs.
Thanks to the Visible Human Project, however, students someday would do
better than just viewing pixels flashing across the screen. They would
be able to tour the body of an actual human. Potential medical students,
moreover, could get a head start. Long before they reached the slicing
rooms, they would be familiar with electronic cadavers and be able to
make better use of the real ones. What’s more, the digitized Jernigan
could revolutionize training in laparoscopic surgery, where doctors
inserted tubes in patients and operated with tiny instruments and
TV-like monitors and cameras. The view on the video screen of a training
computer could be true to life.

All this was not even to mention other applications—for example,
computer-simulated crash tests to improve auto safety, efforts to study
the range of wrist motion and reduce carpal tunnel syndrome in typists,
or investigations of ways to protect athletes against injuries.

I asked Mark Ticer if Jernigan’s family had ever thought of suing for
any of the wealth that the project might create from medical products
and the rest.

The answer pleased me in this litigious era. Ticer said that if anything
the family would be offended that anyone raised the issue. That was the
way Jernigan and his kin were. “There wasn’t a condition attached to his
gift,” Ticer said.

Sharon Kuster, Jernigan’s sister, said her brother would “probably be
happy about it. I am.”

“Now he can be remembered for all the good he did rather than all the
evil,” Ticer said. “I think he’d be quietly delighted.” I picked up on
the “quietly.” Jernigan’s invisibility, prior to his crimes, was not
just because of his station or lack of station in life. That was his
way. Many other inmates on death row gravitated toward microphones.
Jernigan spurned them. The true crime book, if one ever resulted, would
never have come out while he was walking and breathing.

Shortly after I talked to Mark Ticer and Sharon Kuster, my friend Karen
got the results of an intensive examination by a second doctor. It
seemed that Karen would not be undergoing the heart surgery. But even
now she couldn’t tell for sure. What’s more, if Karen received drugs
instead, the medical benefits of the Visible Man might still help her
someday; a major pharmaceutical company, after all, was hoping to use
the digitized cadaver as a tool to explore and demonstrate the effects
of its products.

My thoughts shifted back to Jernigan the human. Lying on the death
gurney, awaiting the poison, would he have wanted to make The Gift if
someone had rushed in and asked at the last minute, “Do you realize
you’ll be all over the Internet? That you’ll suffer the ultimate
invasion of privacy? That strangers from here to Oslo will see your
guts?” I’d like to think that Jernigan would have nodded and the Learjet
would still have flown the body up to Denver. For the sake of Karen, of
other sick people, of those who just might live longer and better if
their surgeons were slightly more skilled, or if they themselves could
make the right decisions about their medical care—for the sake of them
all, I was not-so-quietly delighted that the invisible man was now
visible.

Schools: Park View Educational Centre

The big motto out of the United States, in the 1990s, seemed to be,
“Build jail cells, not classrooms.” Again and again, politicians would
promise to shrink the bloat in school budgets while Fighting Crime; I
shared some of their skepticism toward the edutocracy. Washington, D.C.,
was Exhibit A here. In one recent year the city had shelled out half a
billion on public schools but paid just $2 million for books.

Suppose, however, that U.S. schools had been spending their money in a
way that helped keep children out of jail and helped them learn.
Americans might do well to study Park View Education Centre. It is a
high school up in the Canadian province of Nova Scotia, and something
weird and wonderful had been happening there over the past few years. At
Park View the Internet was not reserved just for the usual suspects—the
would-be Bill Gateses, the local Steve Jobses, the prodigies who already
owned PCs and Macs and were dialing up Christie Brinkley photos on
electronic bulletin boards. Many of the children on the Net were the
at-risk students, those in danger of leaving Park View because of
academic or disciplinary problems.

They were in the “general-stream” track. And just as in the States, the
college-bound children looked down on them. That was unfair. Many of the
general students were bright and simply didn’t want to go to college.
Some of the general boys, not all, wore black leather jackets, tight
jeans, and black boots. And they used razor blades to tattoo the logos
of Ford and Chevy onto their skins. The at-risk girls were less
colorful. But some had disciplinary problems of their own, along with
the same lack of interest in academics. What’s more, certain teenagers
in the area were doing marijuana and hashish and boozing it up; teachers
at Park View worried constantly that the wilder of the students would
turn up on the police blotters.

Fighting against pot smoking and other behavior of the Jernigan variety,
some teachers at Park View systematically used the Net to bolster the
egos of the general students while also improving their scholastic
skills. Yes, alarms went off in my head when I heard the word
“self-esteem.” Too often, at least in the States, this quality came at
the cost of academics. Saying, “You’re good!” was not enough. Gold
stars—if dishonestly earned—would just teach the children that the
educators were liars.

Some teachers at Park View Education Centre, however, were mixing
self-esteem with reading and writing in a way that true Net nerds would
love. And it was happening in a cash-strapped place a continent removed
from Silicon Valley in both distance and technical expertise.

This was not borderline Canada. Park View Education Centre was a good
two days’ drive from the state of Maine. The school served Lunenburg
County, a mostly rural area settled by German-speaking people whose
descendants still reverted to dialect. Bridgewater (pop. 9,000 or so)
was the nearest town. Named for the modest bridge across the La Havre
River, it was in many respects All Canadian—with streets with names like
“King” and “Queen” and “Prince.” Businesses such as Gow’s Hardware and
Rofihe’s Men’s Wear had been in the same families for generations. The
Bridgewater area boasted a Michelin tire plant, too, and a mall and twin
cinemas. And it was growing. But many inhabitants were displaced
farmers, lumberjacks, and cod fishermen; tensions from work or the lack
of it could show up in some homes, to the disadvantage of the children.
When I was researching this chapter, Canada’s unemployment rate was 10
percent, while Lunnenburg County’s was 12-13 percent.

In at least one way, Park View Education Centre may have reflected both
the business climate and the Canadian winters, or perhaps just some of
the educational crazes of yesteryear. Park View was built in the late
’70s with narrow little windows that more or less cheated the classrooms
of a river view. Those slots were somewhat emblematic; many children
hadn’t been outside Nova Scotia. Even among the academic-track students,
fewer than 40 percent were making it to college. Park View, then, was
not quite the stereotypical place for educational high tech.

Still, the provincial government, colleges, and the business community
had been quietly working with Park View and other schools to upgrade the
workforce. In this spirit an education professor at Mount Saint Vincent
University, in Halifax, organized a project called Learning Connections.
Pitching in was the Nova Scotia Technology Network. One idea was to use
computers to hook students in with employers by way of the Internet to
give them a taste of the workplace. It would happen. But something would
overshadow it—student-to-student communication over the Net.

Jeff Doran, a technophobic English teacher at Park View, wasn’t sure
what to think when he first heard of the grand plans. His tenth grade
class of general students did not exactly teem with computer nerds. Many
of the children had flunked a grade. “Some of them had reading levels
down around grade three or four. One or two maybe would have been
considered at a grade ten level. I didn’t have any goal except to try to
keep them in school and keep them in class.” He also had his share of
questions about the project itself. “All we were told was that we would
get some computers, and then we’d get this connection through the phone
lines, and the students would be able to write to people around the
world, and then when the project was over at the end of the year, we
could keep the hardware. I had no idea what we were then going to do
with it, and I certainly had never used it before.” Doran didn’t even
own a television or answering machine. “I still had a phonograph. But I
didn’t even have a tape player, and I had been writing on the typewriter
all my life.”

But Doran had something else going for him, something even more helpful
than technological expertise. And that was an abundance of good,
teacherish skills and empathy for his students, even the ones with the
tattoos. He himself had rebelled. A Harvard graduate, he had fled the
United States during the Vietnam War to avoid the draft. Doran’s exact
political beliefs weren’t the point here, though; a dare-devil Green
Beret might have shown the same ability to brook the foibles of the
general students. What mattered was that Doran cared more about results
than about whether the children followed every little rule. Above all he
cultivated rather than feared the students’ ability to think on their
own.

The Nova Scotia Technology Network provided some technical help, but
would not instantly answer every question. “So,” Doran recalled, “we did
a lot of muddling through ourselves and a lot of teaching of each other.
And that was one of the best things. Some of the students became
teachers because they learned by experimenting, and then they showed
each other. And invariably they showed me, and so I learned from them.
The first thing I discovered was that there could be no front of the
room. It had twelve computers in it that circled around the walls. And
there was no way that I could stand at any point and demand everybody’s
attention. I learned that in about three minutes of the first period.”

Significantly, Jeff Doran’s English class for general students had a
one-to-one ratio between students and computers, a stark contrast to
those in just about all other public schools in Canada and elsewhere.
Students could use the machines not only for networking but also for
word processing. In fact, they started using the machines so often that
in those early days, Doran was holding classes in the computer lab
regularly rather than in the scheduled rooms.

I asked Doran which students he remembered most vividly from those first
days on the Net, and two came to his mind: Betty* and Mac*. Betty was
the only girl of the twelve students on the first day of school. “She
was, uhm, kind of an old-fashioned, sweet-faced girl,” Doran said, “with
one of the foulest mouths that I ever encountered. Yeah. But she had to
be to hold her own against these boys. She was surly and sullen and
stubborn with me, and I don’t think she ever actually came to blows with
any of the boys, but she came pretty darned close.” Betty was brighter
than most in the class. And yet, feisty or not, she lacked
self-confidence. Many would have written her off. More than a few
teachers regarded the general classes as a dumping ground. “She was
pretty unimpressed by what she could do in the computer room,” Doran
said. “She at first was doing most of her assignments by handwriting.”

Meanwhile Mac was hardly off to the most promising of starts. His head
was shaved into a Mohawk. A reform school alum, he was short and stocky
and looked a bit like a small World Wrestling Federation champ,
according to Doran. Mac’s face bore scars from the fights he got into.
He would regularly pound the bejeezus out of other teenagers. “I’m not
sure why Mac was in school,” Doran said. “It may have had something to
do with the law—either school or jail. He was not happy to be here. And
his skills were very, very low. He was about the lowest I had ever seen
in a student.”

Okay, so this was the raw material. I didn’t expect Doran to turn either
Betty or Mac into Oxford dons—everything was relative—but I wondered how
far he had gotten with the computers and the Internet.

“Well,” Doran said, “once she finally started on the computer, she
started writing more than she had ever written before. And I believe
that’s how you learn to write, by writing.” She organized her sentences
and paragraphs better, her vocabulary expanded, and fewer spelling
errors popped up in her work—not just because she could spellcheck but
because she cared more. Her scrawlings in a loose-leaf notebook hadn’t
looked so impressive. But now she could use a computer printer and see
the same, beautiful results as an honors student doing a ten-page
thesis.

“The second big difference,” said Doran, “was that she was writing
e-mail to other students. Suddenly she had an immediate audience. This
wasn’t some make-believe English project where we would pretend to have
a pen pal somewhere and pretend to write to them. This was a real person
who was going to read that message and respond right away, and that kind
of feedback made her, and made all of the students, suddenly aware of
the importance of an audience. And an audience in writing is something
that they had never experienced before, because the audience was the
teacher and who cares what the teacher thinks? Except that the teacher
gives you the mark, so you just write what you think the teacher wants
you to say.

“But now Betty and the others had people who would write back and forth
about their weekends, and their boyfriends, and their dates, and their
sports, and their hobbies, and their cats, and so on. And I think it
opened up a sensitivity to what was acceptable in print, and how your
words can affect people, and the differences between people—especially
over great distances, because a large number of the students that we
were writing to in Vancouver were Asian. In fact they were fairly recent
immigrants to Canada, so their English wasn’t that great. So actually
Betty’s writing skills were better.” And that, in turn, helped her think
better of herself.

Meanwhile Mac, too, was progressing. At the start Doran gave Mac and
others a list of twenty words; they were then to look up the definitions
and use the words in sentences. The time limit was four weeks. Mac
needed the month. He couldn’t even cheat well; copying others’ work, he
blundered because he did not know what he was cribbing. “The last thing
that he could ever see himself doing,” Doran said, “would be sitting in
front of a computer, you know, at a keyboard. With these beefy fingers
of his, he was gonna tap away? I mean, that was out of the question.”

Doran, however, managed to stretch out Mac’s attention span to put up
with the limits of the machines—to give them the detailed instructions
they needed. In computerdom, people use the term “boot up” to mean
turning on their machines or loading programs into them. And, Doran
recalled, “There were times I half expected he was gonna literally boot
this thing across the room.”

“Yes,” Mac snapped back at Doran, “I’ll boot the friggin’ thing up!”

“And yet,” Doran recalled, “within that one year he was writing messages
to pals in other schools and to me as well.”

By then Betty wasn’t just sassing back the boys when they teased her.
She was actually teaching them how to use the equipment. Her marks shot
up to the 90s. Not content just to write a few short paragraphs, she was
turning out well-organized letters several hundred words long in a
professional-looking business format. That was unimpressive by the
standards of academic students, but a true triumph for Betty; she even
zapped off a paper letter to a suspense novelist she admired. The
writing skills she developed on the Net had helped make this possible.

Simultaneously her opinion of herself rose to the point where she was
one of the chattier participants in a video that Park View students
helped make, and that was later shown on a Halifax television station.
Students shot scenes to send across Canada to counterparts at a school
in Vancouver, British Columbia. And Betty showed up again and again on
camera. It would have been nice to write that she went on to college,
but she did not. She ended up a waitress. Partly due to the Net,
however, she surely was a better waitress—more at ease with her
customers, and better material someday for management if that was what
she wanted.

And Mac? “One of the last things I got from him,” Doran said, “was a
message about how he felt he had been changing that year, and how he had
been improving. And I agreed—I thought he had, too. And then just about
that time, he pulled this stupid move and got drunk while he was on a
class trip and got kicked out of the school.” But the story didn’t end
then. “Mac moved to British Columbia and is gainfully employed. In the
boys’ cases, the measure of success is that they are not in jail. In
1990, probably ten boys were at risk of failing and dropping out of
school. Two were at risk of ending up behind bars or dead.”

Reflecting on past and present students at Park View, Doran noted the
little triumphs which led to the big ones. The Net helped whet the
children’s interest in school—to the point where, often, just about all
the students in his first period showed up. It was a virtual miracle,
given the sleep hunger of adolescents.

Clearly the Net could be a truant officer’s best friend. “I use
computers a lot,” one enthusiastic student e-mailed me from Bridgewater.
“I come in on any free time that I have, I even give up my lunch hour to
play with the computer, but I would really like to have more class time
in the computer room.” She said that computers “hold so much wonder to a
person. Like me. Writing on a computer does help out with reading and
writing skills.” Another student, a tenth grader who lacked a computer
at home, told how much he’d enjoyed corresponding with an aunt and uncle
in Winnipeg. At the time he e-mailed me, his relatives had just had a
son, and his e-mail was going into their baby book. Textbooks alone
would never, never have encouraged him to look forward to school the way
the Net did.

I asked Doran if there were any test scores for the children to document
the Internet’s benefits to the children at Park View. He said that
scores by themselves would mislead since he had improved as a teacher in
other ways. And yet he believed the Net had helped; since he couldn’t
supervise the class constantly, he had learned to foster curiosity among
the students as they explored the Net on their own. He and some other
teachers in the experiment understood that they and the children would
be learning from each other, that the old authority models were gone.
The same trend was gradually happening in industry in Canada and the
world at large. So if Doran wasn’t turning out Ph.D.s, he at least was
creating better workers.

Other reasons existed for his success. The videotape reinforced the Net
experiences. The Park View students looked forward to seeing their
counterparts. Much more importantly, Doran let children use the Internet
in ways that meant the most to them. The Net was like the videotape.
Doran had expected his students to shoot pictures of quaint homes, of
beaches, of the usual, touristy sites, when they were showing off the
Bridgewater area. Instead the students photographed the places where
they worked and shopped. And that told all. The e-mail was the same way;
students would most benefit from the technology if it was on their own
terms. At Park View, some virtual romances even developed between the
students and those elsewhere. One boy wrote to a Florida school asking
to be put in touch with a cheerleader.

Yet another explanation for Doran’s success was that students could
spend hour after hour on their computer. So they had plenty of time for
school compositions and for writing letters to friends in Vancouver and
elsewhere. (That wasn’t true of all the students in latter years.
Although Doran felt they did well, they might have done still better
with more time.)

Perhaps most important of all, the machines didn’t put down the general
students the way so many humans did. “It’s been my experience that the
technology benefits the struggling student much more than it does any
other student—in literacy growth, self-esteem, tech skills,” said Lorri
Neilsen, the education professor at Mount Saint Vincent University who
had started the Learning Connections project at Park View and elsewhere.

The positives aside, the Bridgewater experiment was not a complete
triumph. “It’s very important to know the spirit of this project was
carried by a handful of teachers,” Neilsen said. In fact, just eight of
forty teachers in the school participated in the project. Skeptics were
worried about it taking time away from the usual curriculum. Yet another
problem was the authority question; some teachers had to know everything
and were nervous about students learning behind their backs. A third
complication was gender: Many female teachers were uncomfortable around
technology.

Answers and solutions existed to all those challenges. In the case of
academic students, I could appreciate the need to cover a vast range of
subjects that colleges demanded. But with a TeleRead-style arrangement,
just about all the major resources would be online anyway. Old material
over a period of time could be scanned into the national database—a
highly economical way to distribute it, and even better by archival
criteria alone since unread paper material might well disintegrate
anyway without anyone caring about it.

Even with the Net as it existed then, students of all kinds learned many
shortcuts that enabled them to turn out better papers. The knowledge on
the Net was far, far shallower on the whole than at, say, the Library of
Congress in the States. But it may well have exceeded what the students
could find in some small-town libraries. If nothing else, by logging
onto the Net, they could learn how to stay up with the most current
knowledge—no small edge in an era when new products replaced old ones in
months rather than in years, and when academic journals proliferated.

What about the authority question? That could diminish in time if
schools of education shifted gears and encouraged teachers to foster
curiosity rather than have students focus just on textbooks and
teacher-certified facts. Would it happen in the United States without a
concerted, TeleRead-style effort? Maybe. But I doubted this.

If nothing else, public schools needed to give their teachers more time
to master the hardware and the Internet so they would not feel so lost
when their students roamed the Net; the equipment alone wasn’t enough.
“Basic technology training is one of the most neglected aspects of
educational reform,” said Andy Carvin, the Net-oriented educational
expert at the Corporation for Public Broadcasting. “More often than not,
when a school or a school district implements a major technology
overhaul, teachers are introduced to the Internet and all of its tools
in a day or two of ‘training.’” Carvin told me, and he was right, that
teachers should enjoy regular use of the technology at home and at
school so the knowledge wouldn’t fade away. Too, they needed to know how
to “combine that knowledge with traditional teaching and
curricula....It’s like learning to use a telephone—you can be taught to
pick up the receiver and press a few numbers, but if you don’t have
anyone else’s number or don’t know how to give out your own number it’s
useless.”

I asked Lorri Neilsen about Canada, and she said that schools of
education up there were making good progress toward correcting
deficiencies. They had better. In the new era of giant databases there
should be more emphasis on finding _and_ evaluating information from
many sources, and less on parroting textbooks. Teachers should encourage
children to look for malarkey in all media, but especially on the Net,
given all the self-publishing there. Perhaps with more women growing up
with computers, female teachers in the future wouldn’t suffer so much
from the old bugaboos about networks and smart, curious, uppity
students.

That still left another issue—the possibility that students might send
offensive messages over the Net and perhaps fixate on its wilder areas
such as the alt.sex series of newsgroups.

“We did have a couple of cases of students in the school sending
threatening and hateful messages,” Doran said, “but these were not my
students. These were what I would call hackers, computer nerds.” Later
Park View forced students to sign agreements under which they would lose
their privileges if they abused the Net. This was not a hypothetical
issue to me. As I was researching this chapter, I found “Fuck you all”
in the subject line of a public message of a list devoted to educational
uses of the Internet. A student at an American school had taken over
someone else’s account. Making students sign agreements wasn’t a total
solution, but it was a good one. If a student misbehaved and lost Net
privileges, then he or she would be at a considerable disadvantage in
competing with peers.

Addressing the newsgroup question, Park View filtered out the groups it
deemed objectionable. I suspected that a smart student could circumvent
these precautions, but if that happened, he might well have been
intelligent enough to cope with the virtual temptations.

Off the Net, at any rate, students could just as well find questionable
reading material. I remembered the pictures of Marilyn Monroe that my
classmates passed around in elementary school back in the 1950s. Did
anything change? Should we really deprive children of the glories of the
Net under the assumption that the kids were all potential pervs? The
best approach was the Park View—one making children sign agreements that
they would be responsible for their own actions, and suspending or
ending their much-cherished Internet privileges if they abused them.

Risks aside, the Internet was a natural place for students of all kinds.
Only a fool would dwell on the hazards of the net to the exclusion of
the possibilities there.

                  *       *       *       *       *

Would that all activities of government be as benign (well, for the most
part) as those of the schools. In the next chapter we’ll learn about
Phil Zimmermann and his brushes with the darker, almost Big Brotherish
side of government.




                                CHAPTER
                                  SIX

    Governments and the
    Net: Making Sure
    Orwell Was Wrong


If a programmer named Phil Zimmermann had his druthers, he would be
leading a pretty sedate life on the whole. He drives a Saturn, lives in
a small house in a middle-class suburb in Colorado with his wife and
children, and dons a suit and does a pretty good yuppie act when he
consults for East Coast companies. In California he fits in with his
blue jeans. Short and paunchy, he is bearded yet harmless.

Some American bureaucrats, however, would lump Zimmermann in with CIA
turncoats and peddlers of illegal plutonium. In November 1994 customs
agents detained him at a Washington-area airport when he was reentering
the States from Eastern Europe. Twice they combed through his bags then
warned him that in the future he might be in for more of the same.

Why this Kafkaesque treatment? Because many in the U.S. national
security establishment hate Phil Zimmermann’s guts. He came up with
Pretty Good Privacy, or PGP for short—a snoop-resistant way of
transmitting e-mail over the Internet and other networks.

Zimmermann loathes snoops and jackboots. Clearly he was not in the
former communist Europe to subvert democracies; in fact, he was telling
people how encryption[6.1] could help preserve their freedom. “I don’t
have to explain to Eastern Europe,” he said, “why it is important for
their governments not to get too powerful.”[6.2]

This dictator-proofing helped win Phil Zimmermann a “Pioneer Award” from
the Electronic Frontier Foundation, the civil liberties group, which
praised him for creating “a worldwide standard for e-mail encryption.”

Zimmermann, however, as the Net’s many libertarians are quick to note,
may end up in jail for allegedly having violated an American export law
that carries penalties as high as a decade in prison and a
million-dollar fine. The Feds treat PGP-style software as a weapon just
like Stealth bombers, ballistic missiles, and nuclear warheads. And some
Washington bureaucrats hate the idea of such a privacy protector in the
hands of too many civilians who are not, well, Washington bureaucrats.

Even if the Feds don’t indict and convict Zimmermann, the U.S.
government has already done its share of bullying here.

The U.S. Constitution forbids prosecutors from dragging Zimmermann into
an overlit room and interrogating him without a lawyer present. Tell
that to Washington, however. Although the law bans the export rather
than the import of powerful encryption software, customs agents at
Dulles Airport, eager for any excuse they could find, quizzed Zimmermann
when he _returned_ from Eastern Europe. An oft-zealous enemy of privacy,
the Clinton Administration has even promoted the manufacture of
encryption devices that would let Feds listen in on supposedly
confidential phone calls. Washington is also spending billions of tax
dollars to make telephone lines more susceptible to tapping.

Zimmermann, meanwhile, has been working on a phone-style piece of
software. Used on the right computer with a $50 sound card and a $7
microphone, it would let people speak securely over the Internet or
ordinary phone lines.

Bill Clinton’s snoops must love Zimmermann about as much as they enjoy
static during wiretaps. Here’s a man who they fear could break the
connection altogether. Many in Washington, especially FBI Director Louis
Freeh, would love to see unauthorized encryption banned entirely, the
real issue here. And Republican Senator Charles Grassley of Iowa has
proposed to make it a crime to distribute scrambling programs by way of
international nets if the Feds lacked the electronic keys to defeat
them. The Grassley measure would even ban some software now classified
as exportable.

Like it or not, however, Washington no longer can control the fate of
industrial-strength encryption.

Far too many Americans—and Russians, Germans, Czechs, Iranians,
Singaporeans, Malaysians, Japanese, Chinese, you name it—know about the
technology. The Feds instead should focus on different law enforcement
techniques, and on powerful computers to unravel the bad guys’ codes.
But the Clinton people and their allies won’t budge. They keep dreaming
of the mass use of D.C.-blessed hardware and software to let law
enforcement people listen in on supposedly confidential phone calls.
Just like the old Soviet KGB, the Feds think that bureaucracy can
prevail over technology, and that government has a God-given right to
force citizens to be snoop-friendly.

The saga of Phil Zimmermann is hardly the only indication that _some_
Big Brotherism is alive and well in the United States—especially when
one considers other outrages, such as the recent net.censorship jihad or
the elitist copyright proposals that would crimp public debate.

In all fairness, the United States is less backwards on encryption
matters than are countries such as France, which bans powerful
cryptography for private use.[6.3] And certainly Bill Clinton isn’t a
dictator. In fact, the trouble with him, at least at the personal level,
is the opposite: He is too much of a wimp to resist civil liberties
threats from the FBI, the National Security Agency, other bureaucracies,
and the more maniacal of the “law-and-order” crowd on the Hill.

Whatever Clinton’s problem, though, his encryption policy is making him
reviled among many skeptical young people in Generation Net, not to
mention the baby boomers, who suffered lie after lie from LBJ and Robert
McNamara during the Vietnam War. A lifelong Democrat, I voted for
Clinton. I might not again. His constitutional lapses, or at least those
of his bureaucrats, just might help pave the way for true Orwellian
scenarios in the United States and elsewhere.

So might the shameful war that a powerful Clinton appointee has waged
against public libraries, one of society’s best defenses against
Orwellian Ministries of Truth.

“Making Sure Orwell Was Wrong,” then, is an apt sub-title for this
chapter. You’ll remember the basics of the novel _1984_—bureaucrats
tinkered with back issues of the _London Times_ to suit the policies of
the moment, brainwashed the proles of Oceania, and spied on most
everyone with TV cameras. All had to obey the mythical Big Brother. The
most vivid image from _1984_ was a boot smashing again and again into a
man’s face. In the era of mainframe computers bigger than overgrown
Cadillacs, many critics of the Vietnam War invoked Orwell and similar
pessimists. Wouldn’t pasty-faced drones in windowless rooms use the
technology to keep dossiers on us?

Then microcomputers popped up. Suddenly good people could use bits and
bytes to fight back against Big Brother. Amnesty International, for
example, could keep databases documenting murder, torture, and other
crimes by dictators. And then, via the Internet and other networks,
Amnesty could spread the news around and marshal world opinion against
the thugs. Other human rights groups and environmental organizations
benefited, too, and soon most everyone agreed about high tech: George
Orwell had been wrong. Progressives with unpopular ideas celebrated the
new tools available to them. And conservatives didn’t disagree that Big
Brother was dead; if microcomputers could nurture freedom and diversity,
why worry so much about antitrust laws and other regulations? A New York
think-tanker would eventually write a reverse _1984_ in which hackers
won over Big Brother.[6.4]

Meanwhile, an open government movement was growing on the Internet,
along with efforts to use networks as an efficient conduit for services.
Far from being Big Brotherish in all ways, Clinton’s people commendably
put a wealth of official documents on the Net, everything from White
House speeches to reports from the Agriculture Department. The states,
too, acted. Californians could track down a complete set of laws and
proposed laws on the Internet. North Carolinians could hook into an
electronic job bank, indicate their desired kind of work, click on a map
to designate a favored location, and watch jobs pop up. Oregonians could
get fishing-and hunting-license information online.

Bureaucrats in Canada, the United Kingdom, Australia, New Zealand,
Argentina, Finland, Austria, Poland, Japan, and a host of other
countries went on the Net to one extent or another.

Even Singapore, hardly famous for civil liberties and freedom of
information, took a few steps to open up. I was surprised and pleased to
find on a government server a 1993 _Wired_ article with the
not-so-flattering title of “The Intelligent Island?” Like many
countries, Singapore faced a dilemma. Would the country’s strict culture
suffer if the masses were allowed access to the Net? Singapore had
flogged an American teenager merely for vandalizing automobiles; imagine
if authorities instead had caught him in a sex act with a local. The
whip was in character; it was a source of local pride, not shame. And
yet if Singapore didn’t truly open itself on the Internet, if it
couldn’t provide a hospitable electronic environment to
megaconglomerates, the country would fall behind nations with a freer
flow of information.

“Most Singaporeans are little rule followers,” a local hacker told
_Wired_. “They are used to being spoon-fed what they are supposed to
know by the government.” He predicted that Singapore would turn into a
“controlled information center. The government will try to suppress
hackers.”[6.5] And yet the very distribution of the article—for all to
see on a Web server, amid official government documents—told me that the
Orwellian scenario was not a full certainty. If _Singapore_ could ease
up a little, there might yet be a little hope for the rest of the
cosmos.

However, the need for some healthy paranoia remains, even if, yes,
Orwell overstated his case. An Internet Central doesn’t exist for
bureaucrats to shut down, of course; messages can arrive by way of many
paths, and electronic mail if need be can travel over normal voice
lines. But martinets of all ilks can’t resist the urge to censor or
unplug. A government computer in Canada is rumored to be programmed to
reject Anglo-Saxonisms as passwords, and I don’t doubt it. Would that
all outrages were so funny.

Claiming software piracy, cops shut down the electronic bulletin boards
of scores of Italian progressives. “In some places,” the activist
Bernardo Parrella reported, “sleeping people were abruptly woken up
facing machine guns.” The boards were part of FidoNet, a worldwide BBS
system with electronic mail connections to the Internet. Significantly
the police didn’t undertake similar harassment against the high-tech
admirers of Hitler and Mussolini. The victims were liberal or left wing.
Within a year, the Italian cops were back at it again, seizing
computers, disks, books, diaries, and other materials from citizens
suspected of anarchistic sympathies. This time the police made no
pretense; the raids were clearly political.

Politicians and bureaucrats can be just as prickly about sex as about
politics. In Singapore, prudes searched the hard disk of computer
systems to see if the good citizens were enjoying the alt.sex
newsgroups. And back in the States, Senator J. James Exon of Nebraska
concocted a nutty scheme to ban “indecent” material from the public
areas of the Net. _1984_ once more came to mind. Big Brother loathed
sex, as Winston Smith, Orwell’s hero, knew all too well in carrying on
an illicit affair with a female bureaucrat.

Jim Exon also hated sex—at least on the Net. I could appreciate his
worries; did nine-year-olds really need to gawk at alt.sex.bestiality,
or kiddie porn, or the next Brandy’s Babes? Exon, though, again and
again, scrambled his facts. He relied partly on a breathless article
that the _Washington Post_ had run under the headline “Molesting
Children by Computer.” Among other things, writer Sandy Rovner had
advised parents to check their kids’ computers for files ending in
“.BMP”. None other than the Microsoft Windows software, however, left
.BMP files on hard drives—as a way to display images such as the
corporate logo. Might Microsoft be a new Sodom?

“Obviously I had not researched the story enough,” Rovner admitted to
her great credit. “I am new to the world of cyberspace.... I have a
computer coach, but even he is behind on the Internet. Yes, I violated a
cardinal rule of journalism—I didn’t know enough about what I was
writing about. And I certainly wasn’t thinking censorship. Mea culpa. I
am a staunch supporter of the First Amendment, as all journalists are or
should be.” And yet Exon cited “Molesting” on the Senate floor to
justify his repressive, cyberspace-oriented change in the existing
Communications Decency Act. “Argghh,” went Rovner.

Even more significantly, Exon, as noted earlier, failed to grasp the
difference between the Internet and television. Children wouldn’t just
flick on a computer and see a Madonna look-alike climaxing with a German
shepherd. They would have to _look_ for pornography. And the industry
was ready to work on software, such as SurfWatch, to help parents keep
their kids out of pre-designated areas of the Net.

Nothing would be foolproof or teen-proof, of course. Brilliant
technologists had designed the Internet to survive 100-megaton H-bombs.
“The Net,” said the hacker John Gilmore in an oft-repeated quote,
“interprets censorship as damage and routes around it.”

Parents’ best response would be at home. Mothers and fathers shouldn’t
expect Uncle Sam to play nanny. As Steve Case, president of America
Online, noted in connection with his company, parents should never turn
their children loose in a city of millions of people. And I believed
that the same held true of the Internet. Why should parents count on
_everything_ being constantly under control. Put the Net on a leash
short enough to suit Exon, and the pornography would still
persist—encrypted and on non-Net bulletin boards if nothing else—but
legitimate users would suffer. Some Internet providers might even shut
down to avoid legal liabilities. Moreover, in an era of global commerce,
Washington shouldn’t put America at such a disadvantage. The losses in
trade and jobs eventually would reach the billions, given the estimated
hundreds of billions of Net-generated business.

“The only thing that censorship will do is drive the best and brightest
members of the U.S. Internet community to countries where they can
express themselves without risk of reprisal—and drain the United States
of its valuable intellectual capital,” _Interactive Publishing Alert_’s
Rosalind Resnick would later write.[6.6] “Personally I’d rather see a
few four-letter words flicker across my computer screen every now and
then than risk losing talented writers, artists and programmers to our
economic competitors.” A mother of two, she counseled parents: “Keep the
computer in a public area of the house, such as the den or living room,
not in your kid’s bedroom. Warn your kids about the dangers of
pedophiles and urge them never to give out their phone number or address
to anyone they meet online.” _That_ was a far better approach than
Washington-mandated net.censorship, one that could work with the
smartest hacker-child. Even the hyper _Post_ article had played up
similar solutions. But Jim Exon couldn’t keep his hands off the Net.

In a superb illustration of the dark side of electronic democracy, Exon
held up a blue binder full of net.smut and, on the C-SPAN television
network, argued for censorship of cyberspace. The vote in the Senate was
84 to 16—how could U.S. senators oppose “decency?” Given all the sex
scandals on the Hill, it was scene worthy of _Elmer Gantry_, the
Sinclair Lewis novel about a moralizing preacher who nonetheless
indulges in sex and booze. The book, of course, ends with the Rev.
Gantry promising, “We shall yet make these United States a moral
nation.”

Around the same time the Senate was hoping to Disneyize the Internet,
Bob Dole, the Republican majority leader, was protecting Bob Packwood by
opposing a move to open the Ethics Committee hearings into the personal
behavior of the oversexed senator from Oregon. As reported by the
_Washington Post_, Packwood allegedly had grabbed and kissed scads of
women—from campaign workers to female staff members, lobbyists, a hotel
clerk, and a baby-sitter—“sometimes forcing his tongue into their mouth
or fondling them.” Packwood, while not owing up to every particular, had
apologized for being “terribly offensive to women.” And now he and Bob
Dole had voted for Draconian net.morality? Dole had even teamed up with
several other senators, including Charles Grassley, the champion of
snoop-friendly software, to offer a cyber-censor bill worse even than
Exon’s.

The ironies wouldn’t stop. None other than Donna Rice, whose escapades
with ex-Senator Gary Hart had helped kill off his political career, was
now praying and crusading against cyber smut—as a spokeswoman for an
antiporn group.

Another irony hit me. Tobacco and liquor advertisements, which promote
products far deadlier to children than any obscenities, were reaching
the Net. The Internet Sleuth, for example, one of my favorite
collections of Net indexes, had advertised Smokin’ Joe’s tobacco
products over a period of at least several weeks. And yet the Exonians
could not stop fixating on words and pictures, as opposed to a massive,
proven threat that had killed millions of Americans. I didn’t want the
government to ban even cancer-weed ads from cyberspace, lest the
regulators go wild and try to make the Net TV-bland; but if Exon and
allies had to crusade, they might as well be consistent about it.
Perhaps as a true children’s advocate, Exon could even give back the
more than $27,000 that his campaign had collected between January 1989
and December 1994 from the tobacco and liquor industries. That was just
a fraction of his total take, but a statement just the same. Maybe the
operators of “adult” bulletin board systems—who used the Net to post
samples, the real source of the problem—could befriend Exon-style pols
with a well-funded political-action committee. “PornoPAC”?

I wondered what would happen next if the net.censors won in the House of
Representatives. Earlier, in chapter 4, I had quoted Peter Lewis of the
_New York Times_ as alluding to the “pencil-dicked geeks” who flamed
him. Would Washington let _NetWorld!_ go out over an Exonized Internet?
This was the only time I had ever seen such language in e-mail from
Lewis, a gifted professional. Society didn’t prevent a woodcarver from
using a certain kind of wood just because hoodlums might buy some
baseball clubs made from it and split each other’s skulls open. Why,
then, draft legislation that so despicably intruded on writers’ work?
And what about teachers and students of literature, including bright,
stable teenagers under eighteen? Or readers who just loved good,
expressive writing? Knowingly or not, the savages in the Senate could be
banning even _Ulysses_ from the public area of the Internet. Never mind
the forthcoming age of electronic books; might Washington someday go on
to suppress the paper editions from stores and libraries?

Quite correctly the Electronic Frontier Foundation warned of the folly
of turning the public regions of the Internet into “the equivalent of
the Children’s Room at the public library,” and forcing Netfolks to seek
out “adult” areas. Get carried away on an Exonized Net, use the wrong
word, and the Feds could fine you up to $100,000 and jail you for up to
two years. Even in private e-mail you’d need to behave yourself: You
could not harass anyone with an “obscene” remark or image, lest he or
she report you. What if an ex-lover took innocent comments and put them
in the wrong context? Tough luck. Sooner or later the courts would
probably clean up after the politicians and toss out the censorship, but
that would hardly matter to the many who suffered in the meantime.

In July 1995 the censorship debate was still at full blast. Just as Jim
Exon had relied on the misleading _Post_ story, so did his side brandish
a sensationalistic _Time_ magazine cover. A shocked, wide-eyed child
gaped at “CYBERPORN,” as the headline described it “EXCLUSIVE: A new
study shows how pervasive and wild it really is. Can we protect our
kids—and free speech?” Out of character, Philip Elmer-DeWitt, one of the
most Net-aware of all the reporters in the mass media, had relied on a
flawed paper out of Carnegie Mellon University. The student perpetrator
of the study, one Martin Rimm, had overgeneralized, and two professors
at Vanderbilt disemboweled him with a 9,000-word rebuttal on the World
Wide Web. If nothing else, the Rimm study had blurred the distinction
between bulletin board systems and the Internet itself and also confused
Usenet with the Net as a whole.

Carnegie Mellon investigated whether Rimm had violated people’s privacy.
Most deliciously of all, however, from a Net perspective, he had written
something else—a self-published novel with such picturesque terms as
“rectum rocket.” Would that Sinclair Lewis and H. L. Mencken had been
around to chronicle the circus.

Over on the House side, Speaker Newt Gingrich sensibly let his
libertarian side prevail and opposed Exon. I wasn’t surprised. How could
Gingrich play nanny while railing in general against regulation and
bureaucracy, especially when he himself had set up shop as a novelist?
My fellow liberals, though, were amazed. It was as if they were watching
the T-Rex in _Jurassic Park_ gobble up a velociraptor that was about to
enjoy a human snack.

Maybe the Exon-style proposals by now will have suffered the fate of the
smaller dinosaur, but similar lunacy is bound to break out anew.[6.7]
Among some on Capitol Hill, the urge to censor is as powerful as the
passion for reserved parking places.[6.8]

If the censors do win, their narrow-mindedness may backfire in ways
beyond the ones I’ve already described—and these risks will only grow in
the future, as the Net becomes still more international. Puritanical
countries such as Singapore might arbitrarily jail visiting Americans
who, from the States, had made Internet postings deemed offensive by the
standards of local dictators.[6.9] The possibilities are endless. A U.S.
novelist passing through a Mideastern country could become the next
Rushdie if the local ayatollahs deemed his online work offensive.

Clinton’s Feds hardly helped when they went jurisdiction shopping and
prosecuted the owners of a California BBS for sex-related material that
violated community standards in _Tennessee_. Applied internationally,
the local-standards principle could send an American to a sword-wielding
executioner someday. The Bill of Rights, alas, is just a U.S.
phenomenon.

Exon You!

When the U.S. Senate passed Jim Exon’s net.censorship bill, the
journalist Brock Meeks wrote a lead for the ages: “U.S. Capitol, Senate
Gallery—It’s all over. Fuck it.” But what happens if net.censors prevail
someday on the House side, too (if they haven’t already), and you can’t
use the F word? Netfolks have a solution:

_Just substitute the last name of the senior senator from Nebraska._
Enemies and lovers can then say, “Exon,” to each other.

That’s obvious. But the gifted trolls at Bianca’s Smut Shack, spreading
a post from the mythical “Ezra Pound Is Innocent Committee,” have
actually promoted a whole new lexicon in honor of Exon and allies. For
example:

Byrd: (noun) The posterior or hinderparts, specifically the anus.

Coats: (noun) Excrement, or as a verb to excrete.

Exon: (verb) To copulate with, the act of copulation.

Gorton: (noun) The female genitals, or specifically the vagina.

Gramm: (verb) To orgasm. Also colloquially used as a noun.

Heflin: (noun) The female secondary sexual characteristics.

Helms: (noun) The male phallus.

Specter: (noun) The clitoris.

However, a borderless Internet can also hinder the censorship crowd. If
American bluenoses such as Exon tried to restrict an electronic _Tropic
of Cancer_, for example, a U.S. publisher just might set up shop in
countries with less infantile politicians. People in the States could
then dial up the computer overseas.

Already the Net has made fools of martinets in the Canadian government.
Ottawa tried to squelch newspaper accounts of a murder, claiming that
the coverage would preclude a fair trial. So people in the States sent
electronic care packages to their Canadian friends—articles from U.S.
papers. Canadian officials banned a pulped-wood issue of _Wired_ for
attacking their stupidity; that was one of the biggest debacles of all,
given the ease of dialing up electronic versions of the magazine, one of
the planet’s most plugged-in publications.

Consider, too, the ramifications of anonymous servers, which strip names
and other identifiers from messages, allowing Netfolks to circumvent
legal bullying by governments and others. In 1995, the Church of
Scientology in Los Angeles got Finnish police to raid a server in
Helsinki that was posting anonymous exposés of this rather litigious
organization. The server survived. But the cops forced Johan Helsingius,
operator of the server, to reveal the name of a Church enemy who
originated the messages. “Now users fear their secrets are at risk,”
_Time_ said of people using his computer service. Case closed on
anonymous servers? Hardly.

Within weeks after the incident I read a note from a hacker telling how
encrypted messages could wend their ways through chains of anonymous
e-mailers in several countries, with the names of the senders remaining
hidden unless most or all of the e-mailers broke under pressure. Yes,
abuses are possible, such as the release of trade secrets, outright
libels, forgeries, or the most vile and violent of pornography. But how
much better to live out this future than one of the Orwellian variety.
Tyrant-bashers in the Thirteen Colonies used the wizardry of their day,
the printing press, to agitate against the Tories; now let’s hope that
if Exonian politicians try to stifle the Net, enough hackers will have
their most dangerous presses ready to go, the servers I’ve just
described. Obsolete or not, the censors aren’t going to stop.

Other Big Brotherish urges have surfaced. While some Power People hope
to be able to learn more about us by fighting PGP-style programs, they
are stymieing our efforts to learn more about _them_. At the same time
the Feds put online thousands of public documents and even the visage of
Bill Clinton’s cat, some politicians on the Hill sought to _weaken_ the
Freedom of Information Act, which makes it easier to dig up dirt on
public officials. Just as important, Clinton people in early 1995 were
proposing new copyright laws that in effect would discourage the
intelligent discussion of public issues on the Internet. It would be
harder to share electronic newspaper clips. Even more disturbingly,
Clinton’s copyright policy could menace our public library system in the
future. Bruce Lehman, his czar of intellectual property, was coming
across as Andrew Carnegie in reverse.

Carnegie is remembered as a Scot who grew rich off steel in the States
and who encouraged people throughout the world to start libraries for
all. He gave millions toward library buildings, with the understanding
that the local taxpayers would finance their support. Carnegie wanted
public libraries to be universities for the common man, and the metaphor
holds up. Today, without paying for college or even for books, Americans
can educate themselves on subjects ranging from microcomputer chips to
medieval history, to Alexis de Tocqueville’s writings on democracy, to
the case for or against feminism or abortion or public broadcasting or
capital punishment. That is life in the era of paper books.

If Lehman had his wishes, however, Americans would not be able to dial
up copyrighted electronic library books from home by way of the Internet
Instead they would have to tote around CD-ROMs and floppy disks.

William F. Buckley Jr. wrote that, in the era of the Internet, the
Lehman vision would be “the equivalent of requiring everyone who listens
to music to buy 78 rpm shellac records. What will the children dial in
to read? The collected speeches of Vice President Al Gore? And believe
it or not, there’s also talk of the Postal Service getting involved in
local public libraries through information kiosks.”[6.10] In effect the
White House approach would jack up the price of independent, privately
originated information, while making it easier to obtain
Washington-blessed information.

The information kiosks led some librarians to think of noses and camel’s
tents. For the Postal Service at one point said it would let local
librarians and citizens use the kiosks to retrieve only designated
categories of information, as opposed to, say, everything on the World
Wide Web. On a 1 to 10 scale of Big Brotherism, the kiosk idea as
originally proposed was an 8.5 or worse.[6.11] If the postal bureaucrats
weren’t trying to be Big Brother in the strictest sense—and no, they
weren’t—then they at least were unwittingly paving the way for him.

Worse, the Postal Service has talked of issuing tens of millions of
“U.S. Cards” that would “mediate all government services and controls
over citizens,” while at the same time an Internal Revenue Service
official has proposed a system that would file our tax returns for
us.[6.12] I hate both ideas. Rather than compiling Orwellian dossiers on
citizens, governments should help us computerize via TeleRead-style
programs so we can more easily do the “paperwork” ourselves by way of
electronic forms. Investigators could audit the forms, but only under
appropriate circumstances. How much better this would be—not just
e-books, but electronic empowerment against bureaucracy—than the vision
that Washington and other governments have in mind for us.

Perhaps the Lehman idea and the Postal and IRS plans will have been
beaten back or rendered harmless by now. Whatever happens, though, it is
clear that new technology may harm both privacy and democracy if our
vigilance lapses.

The threat of electronic oligarchy, stanching the free flow of facts
that intelligent nonmillionaires demand, is hardly unique to the States.
In the United Kingdom, for example, The _Times Higher Education
Supplement_ has warned against a copyright regime that would be a
paradise for read-o-meter companies but a nightmare to people valuing
free libraries. Just like Lehman’s proposal in the U.S., the wrong laws
in the U.K. could lead to a Copyright Gestapo; let’s hope that neither
country will criminalize one of the prerequisites for democracy:
curiosity.

Given the global nature of both encryption technology and copyright law,
the whole world should be watching Washington’s policies. The Clinton
Administration, after all, hopes to internationalize the same mindset
that could send Phil Zimmermann to jail; in fact, many of the American
export controls _are_ in effect in other countries, raising the
possibility that an Australian or a British hacker could end up someday
in the same predicament. In the pages that follow I’ll tell about the
battles that Zimmermann and his allies have fought with Washington.

You’ll read, too, of my fight for an alternative to the Lehmanesque
copyright law. My little case history suggests that the White House is
not so eager to listen to ordinary mortals who speak up on the Net.
Clinton’s people would rather pander to the usual campaign contributors.
So far at least, pious rhetoric notwithstanding, they have basically
neglected the need to put the public library system online with free or
low-cost books from the private sector. Video just might end up reigning
even more supreme than it does today—at the expense of abstract thought
and democracy. Winston Smith would not be happy.

PGP and the Fight for Privacy—and
Against Clipper—on the Internet

Father Bill Morton, an Anglican priest in Woodstock, New Brunswick,
could take confessions via e-mail without violating his vows. Encryption
software guarded the privacy of his communications. In Florida a bright
teenager without any vices—but with a nosy mother—could protect her
diaries. And in New York, an employee of a leading investment house
could routinely guard his credit card number. The same software made it
possible for thousands to use the Net for confidential business
transactions. At the same time, democratic activists in the former
Soviet Union would be able protect their messages if tyranny returns.

The name for this encryption package was PGP and by 1995 it was as much
a cause as a program. Thousands had downloaded it off the Internet and
other networks. Named in tribute to Ralph’s Pretty Good Grocery on
Garrison Keillor’s radio show, PGP stood for Pretty Good Privacy. PGP
lived up to its name—people needed it. Part of the reason was the nature
of the Net itself. A skilled hacker could intercept unencrypted e-mail
more easily than on the regular commercial networks. Mail often passed
through computers at a number of universities and companies before
reaching its destination. Without question the best way to protect the
contents of your outgoing mail was to scramble its message before you
sent it into cyberspace.

PGP was also popular because its use showed that the Net would never
accept Clipper chip encryption schemes—designed to make it easier for
the government to snoop on citizens.

Not surprisingly, then, at the time I was writing this book, Phil
Zimmermann was a hero to many on the Internet. His program meant
dignity. It meant safer commerce on the Net. Other privacy protection
programs existed, but his was most popular, making it all the more
useful. So when the Feds threatened Zimmermann, many people correctly
felt as if Washington were attacking them along the way. The irony was
that the federal government’s policies against safe encryption could
actually threaten world security and had already set back efforts on
behalf of computer security.

In a sense the PGP story was part of a continuum, and not just because
the Egyptians had scrambled messages four thousand years ago or because
encryption had been a staple of Cold Warriors.

Even while growing up in Miami and Fort Lauderdale, Phil Zimmermann had
tinkered with secret codes. At around age ten he had learned Morse code,
Braille, and, via lemon juice, invisible ink. By his teens he was
building code wheels; at Florida Atlantic University, he kept up his
passion for puzzles and secrets. He started out there in physics;
switched to computer science; married; packed up for Boulder, Colorado,
where he became a computer consultant; and thought of a move to New
Zealand. Phil Zimmermann believed it would be safer, in the event of
nuclear war, than Ground Zero countries.

Instead of leaving the States, however, Zimmermann decided to stay and
help throttle back the military. Along with the astronomer Carl Sagan
and Daniel Ellsberg of Pentagon Papers fame—and hundreds of
others—Zimmermann was arrested at testing grounds in Nevada. Soon his
love of computers would be converging with his distrust of people in
uniforms.

Zimmermann in the early ’80s was selling a gadget that plugged into an
Apple II computer but used an 8088 chip just like the then-new IBM
personal computer. This gadget was designed to allow people to keep
their old Apple hardware and software while running new programs for the
fast new chip. Zimmermann called his company Metamorphic Systems. A
programmer from Arkansas saw a Metamorphic ad and called Zimmermann to
pitch to him an encryption system that was too long to run on most
machines. Would Zimmermann care to adapt the system to run on an 8088
chip? He would.[6.13]

RSA was the encryption method here. Named after its three
originators—Ronald Rivert, Adi Shamir, and Len Adleman—RSA was a
virtually uncrackable form of public key encryption. So what did _public
key_ mean? Well, you didn’t have to worry about the wrong set of eyes
seeing the jumble of letters and other characters that made up keys for
messages transmitted to you. You could freely spread it around. Then
someone who wanted to send something confidential to you didn’t have to
contact you for a secret key known only to you. He could use your public
key by way of his RSA software.

Simply put, the public key approach did away with a major problem: how
to send descrambling tools over networks if the information itself
wasn’t secured. People who didn’t know each other could trade public
keys, then share secrets from the start. They could even use the same
software to verify their identities with the help of trusted third
parties, who “signed” the keys with sequences of their own. Imagine the
many possibilities for allowing safe business transactions on networks
between strangers. A lucrative business just might await Zimmermann if
he added his own wrinkles.

With RSA, however, came a series of legal nightmares for Zimmermann.
Starting work on his own software using RSA, he hadn’t any idea at the
start that Rivert, Shamir, and Adleman would be claiming a patent on it.

The trio farmed their rights out to RSA Data Security and, eventually,
Public Key Partners. Jim Bidzos, negotiating for RSA, in many ways stood
out as a political and philosophical opposite of Zimmermann. Bidzos
carried a Greek passport for business reasons but at the same time felt
patriotic enough to have volunteered for the U.S. Marines. The way
Bidzos tells the story (to Simson Garfinkel, author of _PGP: Pretty Good
Privacy_), Zimmermann asked for a “free license” for use of RSA. “When I
told him ‘No,’” Bidzos said, “he was really upset. He told me that he
was behind on his mortgage payments and that he had invested years in
writing this piece of software.” Bidzos said he suggested that
Zimmermann try licensing the patent from a larger company.[6.14]

Zimmermann’s own side of the story differed starkly—in 1991 he wrote Jim
Bidzos a letter saying that Bidzos and Ron Rivert had told him that “you
would grant me a free license to make and sell products with your
algorithm.”[6.15] A few years later he would note to the _Wall Street
Journal_ that he hadn’t sold PGP before his contract with ViaCrypt, one
of RSA’s licensees.[6.16] He steadfastly maintained he had not broken
any laws. Many on the Internet would have agreed, if for no other reason
than that they considered software patents to be abominations. Without
patents to limit them, many programmers felt they could be more
creative. Their ethos was quite in line with the traditional Net ethos.
The predecessor of the Internet, after all, hadn’t just been started to
allow the Pentagon to survive nukes. It also existed to share knowledge.

By 1991 the patent issue wasn’t the only one dogging Zimmermann. The
U.S. Senate was considering a law that would in effect ban Fedproof
encryption here in the United States and potentially prevent him from
selling the software on which he had been toiling for years now.
Washington already forbade export of encryption abroad. The Cold War was
winding down, but export controls were still draconian. Hadn’t we won
World War II because our technology was better, because we had had
nukes, because we could even snoop on secret code transmissions from the
enemy? The export laws and the Pentagon put strong encryption equipment
in the same category as munitions.

But what about at home? Not surprisingly, the FBI didn’t want the wrong
technology to fall into the hands of dope rings, Mafiosi, and others
planning or coordinating crimes. In 1991, then, perhaps at the Bureau’s
request, Senator Joseph Biden of Delaware inserted the following
language into an omnibus crime bill: “It is the sense of Congress that
providers of electronic communications services and manufacturers of
electronic communications service equipment shall ensure that
communications systems permit the government to obtain the plain text
contents of voice, data, and other communications when appropriately
authorized by law.”

A Senate staffer assured civil libertarians that the measure would not
ban strong encryption. Many disagreed. Computer Professionals for Social
Responsibility, library groups, academics, and industry managed to get
Washington to drop the offending language.

By then PGP was all over the Net. Smart lobbying, not the software,
killed the Biden plan. But Zimmermann’s work was still a good, sound
precaution against a relapse. Via bulletin boards and the Internet, a
free version was circulating from one end of Planet Earth to the other,
having gone overseas within a day of its release. In Zimmermann’s words,
it spread “like thousands of dandelion seeds blowing in the wind.” PGP
reached Russia and scores of other countries. It wasn’t like nuclear
weapons or mini-computers; you couldn’t stop a ship from loading or
search the luggage of the suspicious. No, PGP just moved silently over
the wires as hackers throughout the world shared Zimmermann’s craft. The
way Zimmermann told it, however, he had not broken any of the export
laws. And others supported him.

Jim Warren, founder of _InfoWorld_ and a software man respected for his
civic activism on the Net, would later recall that Zimmermann gave PGP
to an acquaintance named Kelly Goen, who “studiously” limited the
uploads to electronic bulletin boards and Internet sites within the
United States. Warren was aware of the uploading process while it
happened. “The whole idea was to provide it to _Americans_,” he would
remember, “so Americans could have personal privacy and security” in
case the U.S. Senate tried to bottle up decent encryption.[6.17]

The National Security Agency—the secret agency that dealt with many of
the best cryptographers and dominated the encryption scene in the United
States—did not complain formally when PGP first hit the Net. And
Zimmermann fretted. Had his baby failed to safeguard privacy enough to
worry the National Security Agency?[6.18]

Back at RSA Data Security, Jim Bidzos wasn’t thrilled when PGP appeared
with RSA technology. He maintained that PGP violated both patent and
export law, and at his urging, some commercial services and universities
banished PGP from their servers.[6.19] Legally, Bidzos may or may not
have been justified. But once again the hacker ethic prevailed on the
Net. Not everyone online took Zimmermann’s side, but by now he was a
serious hero to a group of encryption boosters known as “Cypherpunks,”
the name that a magazine writer had once given them as a joke.

Many of the Cypherpunks were libertarians, or variants thereof, and they
believed in perfect privacy. The punks were to encryption laws what the
National Rifle Association was to restrictions on firearms.

Along with scores of corporations, not just people whom the White House
might dismiss as fringe, the Cypherpunks wanted to use encryption to
protect digital money. They envisioned a society in which bits and
bytes—representing cash—could pass from person to person without Party A
knowing Party B’s identity. The Cypherpunks were smart, and often very
right. Frustrating for others, but rewarding for them, they tested the
tolerance of the most ardent Voltaireans.

Tim May was among the punk leaders. He had once worked for Intel, the
chip maker. As Steven Levy put it in an article for _Wired_, May had
“‘retired’ at 34 with stock options sufficient to assure that he would
never flip a burger for Wendy’s.” He in some ways came across as the
Internet’s Abbie Hoffman, say, or Jerry Rubin. Baby boomers will forever
recall these bearded crazies of the 1960s who ran a pig for president
and protested materialism by going to Wall Street and scattering money
around.

May did not mind getting rich. But he had something of his own to
scatter in cyberspace. It was a series of taunts that appeared at the
bottom of the many messages he posted to the Net: “Crypto Anarchy:
encryption, digital money, anonymous networks, digital pseudonyms, zero
knowledge, reputations, information markets, black markets, collapse of
governments.” If Washington had rigged up a machine to scan the Net and
measure people by levels of subversion, May would have blown out all the
lights and needles. And one of his programs of choice, as advertised
amid the other subversion? PGP, what else?

Timothy May and other Cypherpunks over the next few years would tap out
thousands of messages, exchanging technical tips, dreaming up new forms
of crypto madness, rallying support for encryption and for Phil
Zimmermann. This was a whole subculture with a language and an ethics
code of its own. Sometimes the Cypherpunks fought among themselves.
Later a punk in Colorado “spoofed” Timothy May and, using May’s Internet
address, posted malarkey all over the Net. But true to his anarchistic
leanings, May did not press for the dissident’s expulsion from the punk
mailing list.

Back in November 1992 the punks may have breathed a little easier.
George Bush lost the election. No longer would the president be a
Republican, a World War II veteran, and a former director of the Central
Intelligence Agency. Bill Clinton was a baby boomer. He had spoken out
against Vietnam, he had avoided the draft, he liked Fleetwood Mac, he
played a saxophone, and his vice presidential candidate had made a name
as a loyal supporter of advanced computer networks. So perhaps the Feds
would back off on Zimmermann. At the very least maybe the security
bureaucracy would face a long delay while the Clinton people puzzled out
what to do.

Clinton’s sax and the rest did not count, however; in encryption matters
he might as well have been a ninety-nine-year-old fan of Lawrence Welk.
Within just a few weeks of the inauguration, two men from the U.S.
Customs Department were quizzing Phil Zimmermann. According to the book
_PGP: Pretty Good Privacy_, they said Jim Bidzos had described PGP as a
rip-off of the RSA approach.

Following the Zimmermann interview, Customs pressed ahead both on the
patent front and on export law issues. Zimmermann, however, denied
having swiped PGP from anyone, and he said patent matters should be
between him and Bidzos, not between him and Customs. At the time the
Feds told him he was not the target of an investigation.[6.20]

Soon, however, two subpoenas suggested that Washington was still quite
eager to justify any and all of the Cypherpunk’s paranoia.

One subpoena went to Austin Code Works, which sold public-domain
software that contained some of Zimmermann’s work. Washington struck
out. It had been seeking evidence of overseas sales, and Austin lacked
any in this case. Zimmermann hadn’t even sold Austin his work
directly.[6.21]

Washington was more lucky at ViaCrypt, a company in Arizona, where the
subpoena stuck. Zimmermann had just given ViaCrypt a PGP license. Now he
indeed would be under investigation. In _PGP: Pretty Good Privacy_,
Simson Garfinkel observed that RSA Data did not win similar honors even
though it had placed encryption-related software on the Internet. Nor
did Internet providers such as Netcom, which stored PGP on computers
that people overseas could reach.[6.22] Bill Clinton’s people were
letting foreigners dial up this export-controlled software again and
again. Needless to say, the bullying of Zimmermann still made the
industry nervous—who was next?

As if the Clinton White House hadn’t sinned enough, it was about to
embarrass itself in a high-tech version of the Bay of Pigs. That’s how
critics regarded a nitwit scheme to control encryption and discourage
the public from using good software such as PGP. The Bay of Pigs, a
cuckoo plan for the invasion for Cuba, was a legacy that had come to
John F. Kennedy from the Eisenhower Administration. The odds would have
delighted no one but a masochistic squad of kamikaze pilots. Castro
crushed a small band of Cuban exiles who showed up on Washington’s
behalf at the Bay of Pigs. Like the debacle on the Cuban beaches, the
Clipper chip was really another Republican leftover. The national
security apparatus hadn’t been able to con the Bush Administration into
implementing Clipper before the election. But Bill Clinton himself
lacked the guts to resist the NSA.

“No Such Agency,” as Washington wags called it, operated out of Fort
Meade, Maryland, near the Chesapeake Bay, perhaps explaining its
fondness for assigning nautical names to encryption plans. Many billions
of tax money had gone into the NSA over the years. Thousands worked for
it. And they weren’t just interested in the survival of the United
States. They wanted job security. Clipper was going to be a meal ticket.
Just as some wishful planners had deluded themselves into thinking that
a small band of men could tame Cuba, now the NSA was telling Bill
Clinton’s people that it could use Clipper to control the world of
encryption.

All those irksome constitutional details aside, the NSA’s plan might
actually have made sense once. The people at Fort Meade had done the
United States a service by staying ahead of Soviet encryption in the era
of tail fins and air raid drills. But today such an approach was about
as appropriate as a backyard bomb shelter. As far back as the 1970s, two
men outside NSA’s control had invented public key encryption, which, as
noted before, was a good way for strangers to exchange secure messages
and authenticate their identities from the start. Whitfield Diffie was a
mathematician, computer scientist, and encryption expert. Martin Hellman
was an electronic engineer. Both were grouchy about a computer system
whose users had to entrust their passwords to the systems managers. So
they came up with public key encryption—the same principle that was
behind the RSA approach used in PGP, and now available from Boston to
Brisbane.

Even Bill Clinton couldn’t repeal the past. Just as the Kennedy
Administration had justified Castro’s paranoia, so the Clinton
Administration worked hard to do the same with that of the Cypherpunks.
This time Washington wouldn’t deploy humans. Instead it wanted to rely
on a little computer chip that Steven Levy described as “just another
tiny square of plastic covering a silicon thicket.”

“Tumor-sized” might have been more apropos. Clipper, in fact, was a
tumor of sorts.

In a human body a tumor serves itself, not its host. And that’s what
Clipper was supposed to do. The Clinton Administration wanted to license
Clipper to the private sector, where it would show up in millions of
telephones and dominate the market—displacing future encryption schemes
based on technologies such as PGP. Washington hoped to make Clipper too
cheap to resist and to provide a federal market for Clipper products.
AT&T and the rest could put Clipper in telephones, and then, supposedly,
dope peddlers couldn’t peddle and terrorists couldn’t terrorize without
the Feds having a chance to intercept their conversations. The
government would also work to make computers snoop friendly.

That was the scenario. Like tumors these government-issue chips were to
spread—not only in the States but also overseas. Eventually the Feds
would also announce plans to make Clipper available through software,
rather than just through the chip. Whatever the incarnation of Clipper,
though, Washington would play down the fact that it would corrode the
country’s constitutional right to privacy. America’s Winston Smiths
would have to trust a government that had covered up an unhealthy number
of deaths from nuclear fallout, given us Watergate, and illegally spied
on thousands of Americans.

An old friend of mine, Margaret “Peggy” Engel, a former _Washington
Post_ reporter who ran and still runs a respected journalism foundation,
was among the snoops’ victims. Bureaucrats got the phone company to turn
over a list of Peggy’s calls even though she had not committed a crime.
It seems a freelance writer had managed to dig up some inside
information on the failure of the IRS to collect several billion dollars
in back taxes from corporations that had profited from currency hedging.
This same writer later applied for a grant from Engel’s organization,
the Alicia Patterson Foundation. Vindictively, the Feds snooped on
Engel, too, simply because the writer had made a call to Engel’s office
for an application for a fellowship.

So it went. Because Peggy and I talked from time to time, the Feds had
also tracked her telephone and computer calls to me. They acted against
her under a casually issued court order signed not by a judge but by an
assistant deputy clerk—one of more than 20,000 such actions issued in
the Washington area in 1992. “It’s like getting your parking ticket
stamped,” she told me. “That’s the level of scrutiny that these things
get. And the number keeps growing. I think it’s because of the increase
in fax machines. I think agencies are using it on their employees to
find out who talked to the press or Congress.” And now the Feds wanted
to license the manufacture of a chip that would spill our secrets on
demand.

Granted, the Feds claimed that in the Clipper’s case, one bureaucrat
could not spy alone. The official line was that people from both the
Treasury Department and the National Institute for Standards and
Technology would have to agree before an interception could take place.
If they did, the electronic keys would go over the wires to local police
or others needing the tap. All this would require a court order. Some
Clipper boosters might well have argued, “We’re talking about strict
controls.” But Peggy’s experience still showed the potential the Feds
had for promiscuous Big Brothering, especially since both the Treasury
and the Institute were within the Executive Branch.

Later the front pages would sprout articles about bureaucrats reading
the supposedly confidential tax information of their neighbors or of
movie stars. Yes, the tax people tightened up their operations to avoid
repeats. But supposedly the IRS had been secure in the first place.

The NSA might itself prove capable of some nasty twists. What if it
could call up escrow keys from a database despite all talk to the
contrary? Or suppose it had a database of its own to unlock all the
keys? Would it really want to go to court for authority to snoop? In
_PGP: Pretty Good Privacy_, Garfinkel wisely noted that Washington would
let Clipper chips be exported. And the NSA was allowed to spy on
nondomestic conversations. So he logically wrote: “If Clipper-equipped
radios were being used by Iraqi fighter pilots, the NSA would want to
listen in. Although the NSA hasn’t said so publicly, it is doubtful that
the agency would jeopardize national security in order to play along
with the escrow system.” The NSA might even work out secret deals with
the company making the chips, to assure that the results didn’t
frustrate the snoops.

Adding to the quite-justified paranoia was the fact that only the
dumbest of criminals would rely on Clipper to protect privacy. So what
was the point of using technology meant to turn the bad guys into jail
bait? Why bother to create it in the first place?

Washington countered that criminals would want Clipper phones to talk
securely to the world at large. And I suspected that, yes, they indeed
would buy some equipment with Clipper. But for plotting a $10 million
dope shipment or a terrorist attack, the black hats would quickly learn
to use other scrambling systems; in fact, they could run them on top of
Clipper so the Feds _still_ got only gibberish. Even if the Feds banned
PGP-style protection, criminals would spread the right hardware and
software among themselves. Like drugs or sex, this would be a fine
opportunity for entrepreneurial lawbreakers.

The underworld might even sell Clipper-crackers that could make
criminals just as good at snooping on America’s Winston Smiths as the
Feds would be. High-tech hoods could call their new business Credit Card
Numbers Unlimited. Small wonder that Clipper appalled many security
specialists.

At the same time, experts for the software industry raised questions
about whether the Clipper chip could penetrate the market and, if so, to
what extent? Any way you looked at it, the plan was crazy. If Clipper
couldn’t catch criminals (and did _everyone_ in the White House really
swallow this bilge?), then who was left? People like Peggy Engel, her
muckraking grantee, and me. At least part of the time, we would need
Clipperish encryption if somehow it surprised the experts and did catch
on; our banks might not let us use anything else. How much better if a
PGP-style alternative were the standard instead.

Technically, Clipper was just as scary as it was politically and in
law-enforcement terms. Scientists and mathematicians loved to dissect
encryption schemes in academic papers, and keep checking and rechecking
them over the years for flaws. But Clipper’s designers withheld the
information that outside experts could use to poke holes in the concept.
Unknowns indeed existed. A well-connected scientist at AT&T would later
find a significant weakness in the network version of Clipper, a way to
cripple the snoop-on-me-please feature.

All in all, Clipper actually emerged as a world security threat.
Washington was harming electronic commerce by promoting a crippled and
questionable program for encryption. The Administration in effect was
delaying the adoption of truly comprehensive security standards for the
international community, especially business people outside the States.
The standards were on the way, but not as fast as if Clinton’s people
hadn’t wreaked havoc on the private sector by way of moronic export
controls.

“We need strong cryptography for mainstream society on the Net,”
Zimmermann told me. “It’s like making locks. It’s as if I were in the
business of selling very, very strong locks.” He reminded me of the case
of Kevin Mitnick, who was arrested for breaking into scads of computers
and stealing oceans of valuable information. The FBI chased him for a
couple of years. “Isn’t it ironic that this guy was able to inflict such
damage because our systems are so insecure?” Zimmermann asked. “Our own
government suppressed the availability of strong encryption technology.
They brought it on themselves, or, I should say more accurately, they
brought it down on us.”

At the same time, through Clipper and through efforts against PGP and
other effective software, Washington in effect was lending moral support
to dictatorships. Clipper used a technique called _key escrow_. That was
a nice way of saying you had to trust Uncle with your secrets since he
had a copy of your key. But what if Uncle weren’t Uncle Sam? What if he
instead were Uncle Saddam?

“You may have the Saddam Husseins of the world, the North Koreans, being
able to hang on to power,” Zimmermann said, “by using this technology to
oppress their own political opposition.”

Clipper could do harm even in countries friendly to the United States.
Washington wanted them to adopt Clipper-style standards. And at the very
least the Clinton Administration was encouraging these governments to
demand the keys to whatever encryption schemes their citizens used. That
could boomerang mightily against American companies doing business
outside the States. Phil Zimmermann recounted to me a rumor he’d heard
about a giant entertainment conglomerate that had negotiated a huge deal
in France; its executives found the French to be uncannily prescient
about the Americans’ tactics. The espionage rumor might or might not be
accurate. But fear of French spying against Yanks was common enough for
many people from U.S. firms to be very careful about what they said on
the telephone, or where they left their suitcases. The French had
prohibited strong cryptography. And the Clipper plan, while not a ban on
decent encryption, certainly deprived American companies of the moral
foundations they needed to protest the French law. In the long run a
Clipper arrangement might indeed pave the way for a ban in the United
States itself against PGP-strength products, and already it could prop
up such moves abroad, to the great disadvantage of American companies
with secrets to protect.

In another way, too, Clipperish approaches would make U.S. companies
less competitive. American software firms wanted to build encryption
into spreadsheets, databases, word processors, and other major
applications. If the Feds bullied them into using Clipper, then their
products would be less attractive than those of rivals. Consider the
market for software to store sensitive material such as medical records;
would a European hospital favor a crippled American program over a
German program with robust encryption?

That wasn’t so abstract a question. An engineer from the giant Siemens
conglomerate in Germany told me later that he was working on medical
software, and he expected his employer to clobber U.S. rivals if their
products used a questionable, Clipperish encryption scheme. What’s more,
crypto mavens were common enough overseas for even American companies to
think about hiring them in the former Soviet Union to bypass the export
controls. If it happened, it would be the ultimate statement on the
absurdity of both the controls and Clipper.

Not surprisingly, a great hue and cry against Clipper came from the
American software industry, and meanwhile the hackers themselves were
waging full-scale warfare against it on the Net. Thousands of Netfolks
participated in the anti-Clipper activities of groups such as the
Computer Professionals for Social Responsibility, the first group to
sound the tocsin.

In 1994, however, as clueless as ever, the White House officially
endorsed Clipper—no ifs ands or buts—and made arrangements for the
production of the chips. “Encryption is a law-and-order issue since it
can be used by criminals to thwart wiretaps and avoid detection and
prosecution,” Al Gore said in justifying Clipper. “It also has huge
strategic value. Encryption technology and cryptoanalysis turned the
tide in the Pacific and elsewhere during World War II.” But exactly.
People on the Net thought that Clipper was just plain brain-dead as a
way to protect security, a triumph of bureaucrats over techies.

You even didn’t have to be on the Net to hate the tumor chip. At the
request of _Time_ and CNN, Yankelovich Partners polled 1,000 Americans;
did they think that private phone calls mattered more than wiretap
powers for police? Four-fifths opposed Clipper. Newspapers churned out
editorial after editorial, and with good cause: Imagine the joys of
trying to expose government corruption if the biggest crooks on the
public payroll might someday be able to monitor your conversations
whenever they wanted.

Quite properly, then, most citizens did not trust Washington. Hackers
wore sweatshirts that played on a slogan that Intel used to promote
computers using its chips. Alluding to Clipper, the sweatshirts read,
“Big Brother Inside.” Tens of thousands of people on the Net lent their
names to an anti-Clipper petition originated by Computer Professionals
for Social Responsibility. John Perry Barlow, the Grateful Dead lyricist
who cofounded the Electronic Frontier Foundation, told how snoopy Feds
would have to kill him and pry his private PGP key from his “cold, dead
fingers.” Through it all, meg after meg of messages went out over the
Net—everything from sophomoric diatribes to carefully reasoned pleas for
anti-Clipper letters to local members of Congress.

After questioning some arguments against Clipper, one man found himself
vilified all over the Net, complete with a lie that he had made a
homosexual advance against a hacker. The privacy movement was supposed
to defend Americans’ right to dissent, not enforce its own form of
alternative orthodoxy. I felt grumpy, then, about the smear. But that
was a relatively rare incident; typical opposition to Clipper was
passionate but high minded.

Except for the smear described above, the meanest statements came not
from Clipper foes but from Stewart A. Baker, a PGP critic who was about
to return to private practice after serving as chief counsel for the
National Security Agency. _Wired_ commendably let Baker give his side.
The magazine did so “with all the enthusiasm,” Baker wrote, “of Baptist
ministers turning their Sunday pulpits over to the Devil.”

Understandably Baker began by denying that Clipper would “create a brave
new world of government intrusion into the privacy of Americans.” Baker
said that key escrow would merely maintain Washington’s rights to do
wire-taps as presently authorized. That was a wrong; the government
actually was going out of its way to make us all tap ready, as if we
were back in the old Soviet Union in the KGB era. But at least in this
case Baker wasn’t maligning the Net. The nastiness oozed out later when
his article took on “Myth Number Two: Unreadable encryption is the key
to our future liberty.” Baker shrugged off such reasoning as “the
long-delayed revenge of people who couldn’t go to Woodstock because they
had too much trig homework. It reflects a wide—and kind of
endearing—streak of romantic high-tech anarchism that crops up
throughout the computer world.” Then he let loose against PGP-style
programs itself. “Some argue that widespread availability of this
encryption will help Latvian freedom fighters today and American freedom
fighters tomorrow.” Presumably thousands of PGP boosters were hunkered
down making bombs in Manhattan basements.

Having tried to ignore the legitimate uses of PGP by thousands of
peaceful, law-abiding citizens, Baker then told how “a high-tech
pedophile in Santa Clara, California, had a PGP-encrypted diary of his
contacts with susceptible young boys using computer bulletin boards all
over the country.” Oh. So between overthrowing the government, PGP users
would be seducing eight-year-olds. Baker huffed that “if unescrowed
encryption becomes ubiquitous, there will be many more stories like
this.”

Poor Baker. If he’d really wanted to do his attacks right, he could have
quoted with full grimness the writings that Timothy May, the Cypherpunk,
had posted on the Net in the spirit of Jerry Rubin and Abbie Hoffman.

May was the author of a long, detailed, sometimes even Talmudic list of
frequently asked questions and answers on cryptography and the fight for
privacy, which might or might not have been on the Net at the time Baker
was writing his _Wired_ piece. But if not, he could have found
equivalent thoughts among May’s many postings to the Cypherpunks’ rather
public list. Laying out the case against strong encryption programs in
the PGP vein, May conjectured that they could make killing for hire much
more practical. People using encryption could rely on trusted agents who
dispensed anonymous digital cash. “There are some ways to reduce the
popularity of this Murder Incorporated system,” May said, and kindly
assured readers that he had been thinking about them.

For good measure May noted that racists such as the Aryan Nation were
using encryption, and “other kinds of terrorists” might be relying on it
as well. “Expect more uses in the future, as things like PGP continue to
spread.” As if that weren’t enough to pull bureaucrats’ chains, May
said: “Many of us are explicitly anti-democratic and hope to use
encryption to undermine the so-called democratic governments of the
world.”

May, ever the idea juggler, also weighed in with some powerful arguments
_for_ PGP that appealed strongly to a stodgy old Democrat (small “d” as
well) like me. Even the Feds should have grasped them. “Could strong
crypto be used for sick and disgusting and dangerous purposes?” May
asked. And then he answered himself: “So can locked doors, but we don’t
insist on an ‘open door policy’ (outside of certain quaint sorority and
rooming houses!). So do many forms of privacy allow plotters, molesters,
racists, etc., to meet and plot.” Whatever May was, anarchist,
libertarian, objectivist, or nothing, he was making more sense in those
three sentences than Baker could have in a 1,000 essays.

After May signed up for Cyberia, a legally oriented list, he was one of
the favorite nonlawyers there, winning friends even among those who
disagreed with his politics. In one limited way he may have been more
threatening to Washington than Hoffman or Rubin, for, rather than just
ranting and raving and putting on a good show, he could communicate all
too cogently with members of the establishment. At the same time the
Feds were fixating on Zimmermann, May casually told the lawyers how he
moved in and out of the country without letting Washington veto his
speeches on encryption. In effect his gleeful confession made mockery of
the laws. If D.C. couldn’t even control a traveler—there in flesh and
blood—how could it monitor electrons speeding over the phone wires?

“I myself just presented a paper on ‘Crypto Anarchy and Virtual
Communities’ in Monte Carlo,” May told the cyberlawyers, at least one of
whom was an attorney from the Justice Department. “I described
algorithms, methods, etc., and was never asked or instructed to submit
to the Men in Black in D.C.” He was even carrying around “several
gigabytes of code, essays, programs.” But never was he “ever stopped,
questioned, or searched. Only upon landing in San Francisco was I asked
to state my business overseas. I said I was meeting with cryptographers
from around the world! This was met with confusion by the
twenty-two-year-old Customs officer; but after asking if any of them
were from Russia or Iraq, and I told him I had no idea if there were or
not, he waved me through.” May said most U.S. cryptographers “just shrug
and ignore the _possibility_ that our papers may be illegal to present
outside the U.S.”

His observations came as the Electronic Frontier Foundation was trying
to resolve matters in a more tidy way. It was sponsoring a lawsuit to
prevent Washington from restricting the spread of encryption-related
writing and software. Quite correctly the EFF argued that the encryption
laws were an “impermissible prior restraint on speech, in violation of
the First Amendment.” An EFF victory, needless to say, could nuke the
government’s case against Zimmermann.

With Hooverian tenacity, as if Phil Zimmermann were Dillinger or a
godfather, Washington kept up its harassment and even escalated it in
some ways. Jim Warren saw this happen firsthand. He had asked to testify
several years ago in Zimmermann’s defense, but the authorities ignored
his request. Then in 1995 he had published op-ed pieces in San Jose and
San Francisco papers, in which he throttled the FBI and NSA for getting
in the way of the best possible security on the Net. In the wake of the
Mitnick break-ins, he had accused the Feds of “endangering millions of
innocent citizens and law-abiding businesses that use the Net or cell
phones, in order to protect their ability to monitor the few who might
be guilty of something.” Almost immediately two U.S. Customs agents
favored Warren with a surprise visit to his house and quizzed him about
Zimmermann and PGP. “When they began the interview,” he said, “they
handed me a subpoena that said I was ‘COMMANDED to appear and testify
before the Grand Jury of the United States District Court’ in San
Jose.“[6.23]

“Who says government isn’t responsive,” Warren quipped.

He said this in a folksy newsletter sent to hundreds of people on the
Net. Its well-earned name was _Government Access_; he had been the main
organizer of a successful campaign to get California to put legislative
information on the Internet for free. As much as anyone he was trying to
work within The System. Yet he was ever skeptical toward “Congress
Critters.” Again and again Warren’s newsletter in effect depicted a
Washington that could be Torylike in its contempt toward Netfolk.

Warren didn’t just write of the well-publicized threats like the Exon
bill, or the Clinton Administration’s prosecution of a couple in
California because their sex-oriented BBS did not come up to Bible Belt
community standards in Tennessee, or the Zimmermann case itself. Warren
also wrote of obscure people such as a Berkeley-area hacker who, enraged
by restrictions on encryption and by other actions in the vein of King
George’s Stamp Act, had fled to Sweden.

“Sweden is no paradise,” the expatriate told Warren via e-mail, “but I
don’t ever worry that the government is going to break into my home. I
know that I’ll be able to run my BBS, maintain all the contacts I’ve
developed over the years, and continue to use the various nets without
fear of Uncle Sam attacking me. So now I’m trading in my U.S. passport
for one that is a lot less threatening to me and my PC.” Warren added:
“This is the second former American I have known who has done this for
exactly these reasons!” I remembered a hacker libertarian who had been
hoping to construct an island in the Caribbean, beyond the reach of
technophobic politicians.

Warren was disappointed enough with Washington to tell the Net: “I’m
beginning to feel like a German Jew in 1935.” He didn’t just hate
Clipper and the harassment of Zimmermann. On top of everything else,
Washington had recently passed a digital telephone bill that “would make
Lyndon Johnson, Nixon’s Watergate team, and J. Edgar Hoover drool on
their bibs.” The project would cost the taxpayers billions of dollars
over the years—all this to make the phone system more tappable, out of
fear that crooks might otherwise forward phone calls to bugfree
locations. Washington was actually setting aside more money for snooping
than for electronic libraries. And now Warren feared that the Feds
someday would ban encryption outright.

Beyond D.C.’s computer-related stupidities, he loathed the way the Feds
played fast and easy with the Constitution on matters such as drug law
enforcement. Agencies, for example, could keep money and equipment taken
from suspects and use them for their own purposes, thus giving police “a
profit motive” to abuse Americans’ rights.

“No doubt,” Warren said, “many in Germany told that nation’s Jews, ‘It’s
not that serious’ and ‘It’s just a phase—it’ll pass’ as they disarmed
the citizens in the name of law and order only a few years before
filling the camps and ovens that somehow good, law-abiding Germans just
never knew about until after the war. If we don’t watch out, our
government’s cure for ‘crime’ will become even more dangerous than the
illness. And this time, I don’t think Sweden will be a safe haven.”

Clearly Warren was a long, long way from the optimism of _Orwell’s
Revenge_, the book in which Big Brother lost to the hackers.

I doubted that the United States was quite as Oceania-like as Jim Warren
obviously believed, and his own German parallel might be stretching it.
Stamp Act parallels did, however, fit. An old, ignorant, Torylike order
wanted to pass laws to contain the new, and I could envision an
increasing number of ugly confrontations between bureaucrats and
Netfolk. Baker, the ex-NSA man, hadn’t hesitated in the least to come up
with his wacky characterizations of Clipper foes. To the D.C. policy
elite, we on the Net were fair pickings.

All the hype about the Information Superhighway notwithstanding, most of
the Feds didn’t feel quite as at home on computer networks as billed.
Most Congress members in mid-1995 still lacked public e-mail addresses.

Meanwhile, the Net was catching on among millions of younger Americans
who surfed freely, while their elders could barely master commercial
networks such as CompuServe. By way of Clipper and blatantly
anti-network copyright proposals, the White House was kissing off all
too many within Generation Net.[6.24]

A further embarrassment was the contrasting enlightenment of some
Republican conservatives, who many Democrats on the Net might have
dismissed entirely in the past. Rush Limbaugh, the right-wing talk show
host, didn’t just show up on CompuServe as a visitor. He personally
logged on again and again and even met his wife there. He might not be
on the Net itself, but he was much more at ease with the technology than
were the majority of the liberals on the Hill. Meanwhile, the most
powerful conservative of all, House Speaker Newt Gingrich, spoke out
against the Exon amendment. William Buckley, the noted conservative
journalist, was a major backer of my proposal for a decentralized
national library system online. And the conservative writer George
Gilder, while all too zealous at times about free markets, had made some
of the most prescient predictions on the direction in which the
technology was headed.

Too many Democrats were TV-centric, while Gilder believed that computers
would be the new entertainment medium, prevailing over television. Sales
figures proved him right. More Americans bought desktops computers in
1994 than purchased color televisions, and it was only a matter of time
until they logged onto computer networks and worried about their privacy
there. And here were Clinton and Gore pushing Clipper with more ardor
than they could summon up for well-stocked electronic libraries for all.

Of course, not everybody on the Democratic side was hopeless, and many
Republican law-and-order types loved Clipper, the Bush leftover. Also,
these same politicians might well applaud the Clinton Administration’s
anti-Net copyright proposals, not understanding all the undertows that
could ultimately drag property rights under. But at least they hadn’t
enlisted civil libertarians and populists in their campaigns to the
extent that Bill Clinton had. I’d never have voted for the man if I’d
known in advance about Clipper, the harassment of Zimmermann, and the
antediluvian copyright policies. Bush in some ways might have been
preferable. Not knowing the difference between a potato chip and a
silicon chip, he would have done much less damage. A smarter, more
principled Democrat than Clinton could pick up the pieces in ’96.

Clinton’s Justice Department showed a brazen and bizarre lack of
fairness toward Zimmermann. Until the statute of limitations expired—and
that was fuzzy, even to lawyers—the Feds might just let him dangle.
Without finding Zimmermann guilty of anything, or even charging him,
Washington in a sense was already leveling penalties. He had to spend
hours and hours away from his regular consulting business to work on his
case.

Total costs might reach $300,000 if the prosecutors decided to act. Even
if lawyers donated their time—and Zimmermann might enjoy the services of
some noted attorneys outraged by the threat to civil liberties—there
would be the burden of telephone costs, travel, and hotels. Appeals for
donations went up in such areas of the Usenet as talk.crypto.politics,
comp.org.eff.talk, and, of course, alt.security.pgp. People could pay by
credit card, encoding their numbers via PGP.[6.25]

In the end, no matter what happened to Zimmermann, the real victory
might be in the marketplace. And there Clipper was losing. AT&T and a
chip maker named VLSI Technology came out with a chip that would
challenge even the NSA’s supercomputer. Given a choice between that and
Clipper, who’d want the latter? Even before then, in fact, few customers
were going for Clipper-based equipment.[6.26] In the end it looked as if
Washington would resort not to a chip but to continued pressure on U.S.
corporations to make available the key schemes of more secure plans. And
even then, I hoped, the industry would balk. The more such foolishness
became a habit here, the less protected would be American companies
abroad, as people outside the States followed Washington’s example.

Some of the biggest Clipper haters, meanwhile, were overlooking their
differences to unite against the tumor chip. Jim Bidzos’ company had
already granted a license for the basic technology to ViaCrypt, which,
at least in the latter’s opinion, left it free to sell a commercial
version of PGP. And this past action may have been a door opener in a
way for Phil Zimmermann. PGP was no longer so much of an outlaw program
in the eyes of many, and businesses felt they could use it and get
technical support. Beyond that, professors at the Massachusetts
Institute of Technology, whence much of the RSA technology had come,
were sick of all the patent wars. They just wanted to see solid
encryption in use. And Bidzos, however much he quarreled with
Zimmermann, was himself determined that the Feds not control encryption.
The compromise could go a long way toward enshrining RSA as at least an
informal world standard, and thwarting RSA’s biggest competitor, the
NSA.

And so Bizdos and colleagues let PGP be used for noncommercial purposes
as long as the newer versions were incompatible with the older ones that
lacked the blessing of RSA and Public Key Partners. Of course that still
didn’t solve the hassles of securing international commerce with a truly
strong encryption standard with which the U.S. government felt
comfortable. But even if PGP-style products weren’t official, they were
murdering Clipperish schemes before snoop-ready chips and programs could
take root. The world’s governments might well have to join countries
like France and try to ban strong encryption.

But could they? Too many people in too many countries were already using
software such as PGP. Hackers proudly included their public PGP
keys—those weird combinations of letters and numbers—at the ends of
their messages or told how people could obtain them. PGP keys were
becoming status symbols. PGP wasn’t yet built into popular e-mail
programs such as Eudora for easy use, so, if nothing else, the keys
indicated a certain level of technical expertise. They were the new
vanity plates of the dataways. PGP was even becoming a small industry;
for example, you could shell out $20 and officially register your key
with a company in Palo Alto, California, called SLED. And then people
receiving messages from you would know they were really from you.

SLED required a mailed or faxed driver’s license or passport, or a
preprinted personal check. This wasn’t the best proof of identity, but
it would at least let Netfolks spot obvious forgeries immediately. If
nothing else, you could “register” your key with friends who were well
known and well trusted on the net.

With or without formal registration, more and more Netfolks felt lost
without their PGP. Father Bill Morton, the Anglican priest mentioned
earlier, the one who used PGP to accept confessions over the Net, wrote
a parody:

               _It’s one for the money,
               Two for the show,
               Three to get ready,
               Now go, cat, go!
               But don’t you step on my PGP.
               You can do anything, but lay off my PGP_.

Responding to a query I’d posted in several encryption-related
newsgroups, he explained in an e-mail why PGP meant so much to him.
Confessions were just part of the story:

    _In the history of Anglican pastoral care, there is a strong
    tradition of the use of the letter as a means of spiritual
    guidance. Actually this tradition goes deep into the roots of
    the Catholic Church. Some of the books regarded as “spiritual
    classics” are compilations of correspondence between a person
    and their spiritual director. Until the advent of PGP, e-mail
    was not a suitable place for such correspondence. It’s one thing
    to have your correspondence published 100 years after the fact;
    it’s quite another to run the risk of having your personal
    thoughts posted to a Usenet newsgroup or read by the sysop of a
    BBS. Now they know that even if they hit the wrong button and
    send their e-mail to the wrong place, it is secure....
    Legislation that would make encryption illegal or require a
    mandatory backdoor would totally compromise any trust in e-mail
    or any other form of electronic text system such as word
    processors._

Father Morton’s respect for privacy came through when I asked for
examples of confidences that people had shared with him by way of PGP:
“No matter how I disguise the facts,” he told me, “even if I were to
create a fictitious person, someone somewhere would believe that they
were reading the details of their life story.” And so he was vague,
other than to say, to give an idea of the gravity of what he heard,
“Thoughts, dreams, hopes, as well as lust, anger, and hatred. Sometimes,
actually oftentimes, there are things that you wouldn’t even tell your
spouse. Our lives are based on trust.”

Thanks to PGP, Father Morton could maintain that trust not only with
people locally in Woodstock, New Brunswick, but with Netfolk from
thousands of miles away.

Some people met him in newsgroups. “We’ll have an exchange of e-mail on
a specific topic,” he said, “and at one point it will become evident
that I am a priest.” He neither hid nor played up his occupation. Upon
learning it, he said, the Netter at the other end “may wish to change
the topic and enter into a brief correspondence about a particular
question. That conversation might last one or two posts and is usually,
though not always, in PGP.” In addition, he corresponded with a very
small group of people regularly about significant events in their lives.
These conversations were always in PGP.

“Before PGP,” Father Morton said, “e-mail was guarded in its content. A
typical e-mail exchange might be to set up a phone conversation or
meeting or discuss issues in very general terms. Now, at least in a few
cases, the PGP mail is much more open in its content, and as a result
the e-mail pastoral relationship can be much more productive.”

Father Morton was not alone in his use of PGP to protect personal
secrets. For example, the Samaritans, a group devoted to talking people
out of suicide, said it would accept PGP-encrypted messages.

“The Samaritans,” announced a Usenet post, “have always taken the
confidentiality of callers extremely seriously. Indeed the most
frequently asked question within the movement about our e-mail service
is, ‘What about confidentiality?’” Surely, in an era when more and more
communications happened to be electronic, it would be folly to deny
reliable encryption to the Samaritans and the people they helped.
Although the Samaritans felt more confidence about the security of
unprotected e-mail than did Father Morton, they understood an important
truth: _perceptions_ mattered as much as anything. If their
correspondents lacked faith in the confidentiality of e-mail, they
couldn’t write as freely. And, as I saw it, they might not be as open to
rescue. If Washington banned PGP, if it replaced it with an inferior,
Clipperish arrangement, the Samaritans just might not be as successful
as with truly secure encryption.

Privacy wasn’t just for confessions and for suicide prevention. It was
also for teenagers. Donna—she supplied her real name but I’ll protect
her with a pseudonym—lived in Florida and was a seventeen-year-old
junior in high school who was already using PGP. She e-mailed me:

    _I couldn’t speak for other teenagers and their parents, but
    with my extremely intrusive mother, I use all the privacy
    devices I can get. I’ve kept extensive journals since second
    grade—she’s always read them and nosed around, no matter where
    I’ve tried to hide them. She’s opened letters from friends and
    pokes her nose into anything that she considers unorthodox; we
    don’t quite see eye to eye on many issues. I’m a good student,
    responsible, don’t drink or do drugs, blah blah blah, but she
    has continuously invaded my privacy over the years despite her
    lack of justification._

    _Two years ago I tried a locked drawer where I kept all of my
    papers, letters, and the like, but she has opened the drawer
    with my keys. So now I just do everything on the computer and
    encrypt/password it. I can see how some parents might justify
    searching their kids’ rooms—just as police can under
    circumstances justify searching homes._

But, Donna went on, if a child were doing something _illegal_, there
“would be physical evidence.” That seemed clear: You could encrypt a
diary full of unorthodox musings; you could not encode a marijuana
stash.

I would have trusted Donna, but I still had mixed feelings about most
teenagers using PGP without their parents’ sharing the keys. How long
until Senator Exon ranted that the young would encrypt dirty bytes? In
the end, however, just as with children’s use of the Net itself, PGP
should be a family decision, not a federal one; Washington mustn’t turn
into a giant version of Donna’s mother. Risks from a ban, even one
limited to children, so outweighed the benefits. If Donna’s mother
wanted to understand her daughter, then maybe she needed to spend less
time doing a domestic-level KGB act and more time at a computer—seeing
for herself what her daughter was up to. In the process she might
understand Donna well enough to tolerate her opinions. She’d better
learn to brook them; her daughter was almost eighteen, the age of
adulthood in the United States. Soon many parents would be more
comfortable with the technology, and then, family by family, parents
could decide whether to be Big Mama or Big Daddy and look for
PGP-encrypted files. It should be a family, not a government, matter.

If nothing else, parents themselves could use PGP to guard their own
privacy. “I use PGP at home solely for keeping confidential information
from prying eyes—for instance, from my son and my son’s friends, as well
as for keeping their information in one central place,” said Joe
Collins, an employee of an international investment bank based in New
York. It guarded his burglar alarm codes, the codes to the family safe,
all credit card numbers, and all passwords to software on the family
computer. Yes, some popular software came with encryption, and certain
people might have argued that home users such as Collins didn’t need
PGP. But the encryption found in popular software was nowhere near in
PGP’s league. In fact, Crak Software, a company in Phoenix, Arizona,
even sold “password-recovery software” to crack popular programs such as
WordPerfect, Word, Excel, Lotus 1-2-3, and Quattro Pro (for backup
purposes).

AIDS activists especially understood the possibilities of good, strong
encryption; victims of the disease, after all, were treated about as
fairly as lepers had been in biblical times. In New York a group called
ACT UP tried to get the public health officials to encourage labs to use
PGP to protect the identities of patients. The officials liked the idea.
The program died at the hands of a parsimonious governor; but sooner or
later, I suspected, PGP would be used in one way or another to protect
the privacy of AIDS patients, if it wasn’t already.

In the business area, the advantages of keeping PGP legal—and avoiding
Clipperish solutions—were just as clear as at the personal level. “PGP
is essential,” said Robert David Steele, a former CIA agent whose
passion for legalized encryption and dislike of Clipper must have
endeared him to many hackers.[6.27] “Security is the foundation for
openness. In order for a world of open electronic exchanges actually to
succeed, electronic persons have to know three things, all of which PGP
supports: (a) that the person on the other end of the link is who he
says he is, (b) that the information being received is genuine and not
altered, and (c) that a digital cash payment will be forthcoming,
assuming that this is part of the transaction.” Steele was not just
talking about the benefits of PGP for business alone, but clearly it was
among the major uses that he quite properly had on his mind here.

Many business people on the Net agreed. I was hardly surprised to read
in the _New York Times_ about the use of PGP “in what was apparently the
first retail transactions on the Internet using a readily available
version of powerful data encryption software designed to guarantee
privacy.” A Philadelphia man had used PGP to scramble his credit card
number and spent $12.48 and shipping costs on a compact disk with rock
music from a New Hampshire company called Net Market. More benefits were
to come. Already other companies were working on digital cash, which
could let bits and bytes go out over the Net in ways that prevented them
from being easily traced. They would be, in other words, just like
dollar bills.[6.28] You could spend them without Big Brother knowing
that you’d bought a _Playboy_, a Rush Limbaugh book, a condom, or
whatever else might somehow cause your neighbors or your boss to take
offense.

PGP also made sense for privacy protection _within_ companies. An
accounting firm in Palo Alto, California, for example, used PGP to guard
backup tapes in case of loss or theft, and a Washington accountant
relied on it for client communications.[6.29] And when Zimmermann
himself asked online for PGP testimonials, a man with a
telecommunications firm on the West Coast told him how much he loved it
as an alternative to Clipper:

    _Once it becomes a standard, the competitive software industry
    will have no incentive to continue technical development in
    crypto. And then once Clipper gets cracked by outsiders or
    otherwise compromised, there will still be a lot of bureaucratic
    inertia protecting it and keeping the fact that it’s been
    compromised a secret._

    _We see a serious need for crypto to protect client records
    regarding their telephone systems and computer networks, to
    protect our internal company memos sent via e-mail, and to
    protect strategic business information sent via e-mail. We
    figure that a misrouted piece of client data is a potentially
    serious liability issue, and a misrouted sales proposal or
    similar business document is like leaving a credit card on a
    park bench. Due diligence, fiscal responsibility, and all that.
    The big plus is simply that we will be able to confidently move
    a lot more of our business online, which will make a huge
    difference to us. More efficient handling of client requests,
    more efficient internal discussions, and more effective
    communication with investors. In particular I do a lot of
    strategic business planning online, and it always bugs me in the
    back of my mind—‘What happens if this gets lost on the
    Internet?’ In one sense good crypto is like a good business
    dinner. It facilitates the flow of ideas in a relaxed
    atmosphere._

At the same time, needless to say, PGP could improve the flow of
_political_ ideas. In 1993 Boris Yeltsin had been at odds with foes
nostalgic for the old Soviet state. “If a dictatorship takes over
Russia,” a message from Latvia had told Zimmermann, “your PGP is
widespread from the Baltic to the Far East now and will help democratic
people if necessary. Thanks.”[6.30] In Burma rebels used PGP against an
oppressive regime. A writer in Thailand said that before PGP reached
them, captured papers had “resulted directly in arrest, including whole
families, and their torture and death.” Activists in El Salvador and
Guatemala also relied on the program. “In this business, lots of people
have been killed,” said Daniel Salcedo, a member of the Human Rights
Project of the American Association for the Advancement of
Science.[6.31] David Banisar of the Electronic Privacy Information
Center told me of PGP being used in Kenya, Mali, Senegal, Egypt, and
Mali, among other countries.

“Wire tapping is conducted in nearly every country in the world,”
Banisar wrote in a paper with the marvelous title of “Bug Off!” “It is
frequently abused.” A 1992 State Department report, for example, told of
governments and private organizations snooping away in dozens of
countries. And it hadn’t happened just in the Third World. “There have
been numerous cases in the United Kingdom which revealed that the
British intelligence services monitor social activists, labor unions,
and civil liberties groups,” Banisar said in a paper written for Privacy
International.[6.32] What’s more, the Canadian Communications Security
Establishment had shelled out more than $1.1 million to scan through
millions of messages and pick out dangerous words and phrases.[6.33]
Would the CCSE abuse the system and routinely compile dossiers on
law-respecting people? And what about the FBI here in the States? Many
Netfolks took it for granted that Louis Freeh’s people were keeping up
with Usenet.

“The FBI has the ability to police the Internet and, indeed, has been
doing so,” David Nadler and Kendrick Fong, two tech-oriented lawyers,
would write later on in _Computer Digest: The Journal of Professional
Development for the Washington-Baltimore Technology Community_. “In
fact, the FBI has been collecting Usenet postings since the late 1980s.”

A formulaic condemnation of all FBI monitoring, however, would be
unfair. I could hardly object to the Feds reading the public messages of
egotistical nuts with a clear-cut predilection for violence. What better
reason _not_ to censor Usenet and any audio and video equivalents that
might follow? Let the kooks rant away, hour after hour, educating Louis
Freeh about their plans. Usenet wasn’t anyone’s living room. Posting
messages there was like publishing a book or speaking in a town square.
Via the free Stanford Netnews Filtering Service, I could receive
electronic mail messages whenever a specified word showed up in a major
area of Usenet. Yes, I could track people by name. I could also choose
words associated with a topic. That was the magic of the Net; it gave us
small-fry many of the same tools available to the intelligence
bureaucracies. The same kind of wizardry that might let Canadian cops
snoop on citizens could allow me to track the utterances of Al Gore on
the subject, say, of the Internet.

One technology, however, may have bureaucrats more uncomfortable than
any other—encryption. A U.S. database expert named Patrick Ball found
this out the hard way when he was in Ethiopia to help the Office of the
Special Prosecutor. Ball efficiently helped build a database of crimes
that had occurred under the regime of Mengistu Haile Mariam. He was
accomplishing plenty. Then a bureaucratic rival started a turf war with
him. The man falsely claimed that Ball had been using PGP for secret
correspondence, probably with the CIA, even though the truth was a
little more mundane. Ball hadn’t used PGP for anything but test
messages; the people at the other end lacked the technical skills. But
the rival didn’t know. He confused PGP with uuencoding—a way to prepare
programs for accurate transmission via e-mail—and unfortunately the
chief special prosecutor believed Ball’s accuser and forced the database
expert to resign.

So often that was the case with police: They displayed a mix of fear and
ignorance. And they were not totally wrong to be worried. One computer
expert predicted that in the next few years criminals would routinely
use electronic scrambling. “This could signal the end of computer
forensics,” said William Spernow, “before it even gets off the ground.”
A criminal relied on a double set of books, employing PGP to conceal the
accurate one, and dope-peddlers in Miami used encryption.[6.34]

Not only that, just as I was writing part of this chapter, the
newspapers told how terrorists in Japan had killed 10 people and injured
about 5,500 by spreading nerve gas in a Tokyo subway station. Wouldn’t
restrictions on encryption make such acts harder to commit with
impunity?

Strong counterarguments existed, however, against the jackbooters who
would ban strong encryption or impose the Clipper variety on us. I would
rather that nations not spy on each other. But I fully recall the
naiveté of the past, the fantasy that “gentlemen do not open other
gentlemen’s mail”; whether we liked it or not, espionage and
counterespionage would always go on. In that spirit, instead of wasting
money on Clipperish schemes, countries could spend money developing more
powerful computers to crack encryption, and they could also refine the
unscrambling techniques. That would not be cheap. But since bad guys
wouldn’t let Clipper or successors be the apex of technology, the United
States hadn’t any other choice. Other countries might feel otherwise.
Bureaucrats just couldn’t contain technology. Clipperish schemes would
be brainless in any country.

As one alternative, governments could rely more heavily on open
sources—for example, newspapers and other media outlets, especially
those online. The more journalists out there, and the more independent
they were, the harder it would be for nations to keep secrets and
conspire against each other. The United States and friends had the most
selfish of reasons for encouraging the spread of the free press.

The open source idea was hardly original to me. Others had talked about
it for years, most notably Robert Steele, the ex-CIA agent, who observed
that publicly available material was often far more useful than the
clandestinely gathered variety. I didn’t agree with much of what Steele
said—I wanted more isolation between journalists and government than he
might have liked. But his basic point was sound. Information was most
reliable when it was in the open and could be dissected, rather than
hiding it behind a “secret” stamp. The spread of network technology
could only strengthen this premise.

Yet another approach could be the selective use of agents, in new-style
roles, taking advantage of high technology. Here again I had mixed
feelings. But in an era when countries such as Iraq were trying to
develop nuclear weapons, this option should be kept alive.

What about terrorists? As with child-molesting rings and drug cartels,
Clipper just would not do any good. Secret groups would be the last in
the world to use the chip. Far better for intelligence agencies to work
on more powerful computers and truly effective software for cracking
codes. Breakthroughs might not come immediately, but would sooner or
later, and the civilian sector might ultimately benefit when the
technology finally did reach the world at large. Advanced
supercomputers, for example, could be used for weather forecasting, or
for graphics and design—the same wizardry that had helped make possible
the Visible Human Project described in the last chapter.

Meanwhile an open-source approach could often do the job. The accused
terrorists in Japan hadn’t exactly stayed hidden from the world before
the subway incidents. Shoko Asahara, their leader, had delivered sermon
after sermon with allusions to poisonous gas; in the city of Matsumoto
where he had been at odds with authorities over some land, 7 people had
died and 200 had suffered injuries when a cloud of sarin wafted in the
area. Small wonder that the Japanese government had caught up with the
sect so soon after the Tokyo tragedy. Newspaper databases would have
told plenty, beyond any information that happened to be in the
government’s own records.

Legally authorized bugs might be yet another solution, and so, at times,
might be informers wired to make the best case. In an era of
near-invisible electronics, this approach would be increasingly
practical.

What’s more, if Bill Clinton and Al Gore really cared about protecting
citizens in a high-tech age, they would worry less about snooping on
citizens and more about hardening up points of vulnerability. Steele
noted how easily criminals could “maliciously interfere with the
computers that control the power system. It is relatively easy to
destroy computer capabilities—this takes much less skill than to ‘crack’
them and divert computing resources.” Also, terrorists could wreak havoc
with computers that controlled telephone systems in such areas as
communications for government and banking.

He also warned of interference with the computers of Wall Street and the
Federal Reserve. “Trillions in digital data” could vanish into the
ether. “A massive global economic panic” would ensue. Preventative
measures wouldn’t be cheap, but if the American government did care
about security, it would prepare realistically for the threats of the
information era rather than doing an inept Big Brother act.

To rig up a whole nation for wire taps would be both a waste and a
disgrace. I pondered the ironies. Here the NSA and similar agencies were
supposed to protect normality—to guard families against dopesters, sex
perverts, terrorists, and the rest—and yet Phil Zimmermann the husband
and father might go to jail. “I think it’s kind of unreal to him,”
Zimmermann said when I asked how his son felt about this. “I tell him
that I have some talented lawyers working for me, and that we’re doing
the best we can.” And Zimmermann’s wife? “She thinks that they can’t
possibly indict me, because that would be wrong—that somehow they’ll
realize that and just back out. Of course by the time your book is
printed, we’ll know one way or the other whether she was right.”

A Few Words about Library Books,
Democracy, and Socks the Cybercat

The White House in the 1990s was extolling computer nets as a way to
Bring Government Closer to the People. Americans could dial up “An
Interactive Citizens’ Handbook” on the Internet, see a photo of a
teenaged Clinton with JFK, and listen to Socks the Clinton cat meow. But
could Clinton-Gore hear _us_? Just how “interactive” was the White
House?

Clinton boosters formed a group called Americans Communicating
Electronically to improve electronic contacts between mortals and
bureaucrats. Al Gore, meanwhile, had flaunted his typing skills with the
famous visit to CompuServe. But was electronic democracy truly alive on
the Internet and other computer networks? Not quite. All the techish
sizzle notwithstanding, Clinton-Gore might instead be giving us
electronic oligarchy, especially if Republicans followed the horrible
precedents that the White House was setting. Consider the dubious,
somewhat Orwellian process that was shaping the National Information
Infrastructure—the famous data highways and related endeavors.

So far Washington had not worked nearly as hard as it should to drive
down the cost of knowledge for the average American. At the same time a
network-hostile copyright proposal was delighting information
monopolists and imperiling the ability of citizens to share electronic
newspaper clips in even a limited way.

I testified at an official hearing on the NII in 1993, and what most
struck me about Clinton-Gore was the chasm between words and deeds—the
same mind-set that led to Oceania’s propaganda agency being named the
Ministry of Truth. The gospel according to Al Gore was that people of
all income levels would be able to travel the dataways. His musings
later adorned the peach-colored newsprint of _The Mini Page_, a
newspaper insert for children.

“No longer will geographical location, wealth, gender, or any other
factor limit learning,” Gore reassured elementary schoolers. He told how
“a child from my home town of Carthage, Tennessee, will be able to come
home from school, turn on a computer, and plug into the Library of
Congress in Washington, D.C.” The NII would clearly be in the grand
democratic tradition, small “d.”

The next day, however, the _Washington Post_ carried news of a
different stripe from Bruce Lehman, the Clinton-Gore commissioner of
patents and trademarks, who chaired the NII working group on
intellectual property. I learned that “because of the ease of digital
reproduction, Lehman does not foresee that digital libraries will put
copyrighted works within easy reach online the way they do books on a
library shelf. Copyrighted digital materials are likely to be
available only to subscribers—libraries, for example—who pay royalty
fees, he said. People who want the material might have to go to their
local library and use a computer there that would not allow them to
copy or redistribute the work, Lehman said.”[6.35] A few months later
Bruce Lehman would graciously tell the _Wall Street Journal_ that,
yes, he would tolerate children carrying home copyrighted CD-ROMs and
floppies of electronic books.[6.36]

Compared to networked books, however, the CDs and the rest would be
pathetic. Distribution over the Internet and other networks could be the
cheapest way to get the material spread around, while assuring a wide
variety of material for all. When William Buckley likened CD-ROMs to
78-rpm shellac records in the era of the Internet, he couldn’t have been
more precise. And yet this was the future as envisioned by Bill
Clinton’s intellectual property czar. So much for the well-informed
citizenry needed for a Jeffersonian America. Lehman was beating the
bushes for electronic oligarchy.

Once I had felt that the Clinton-Gore people might truly share my own
egalitarian dreams. I’d thought that nonlobbyists like me stood a
healthy chance. I had been writing about computers for close to a
decade; earlier I had covered a poverty beat, and I knew how we could
drive down the cost of small computers so that someday even Head Start
kids could read electronic books on them. What better way to encourage
democracy? The whole country, not just the elite, could grow up
understanding abstract thought. Could the Constitution have been drafted
by a mob of illiterate TV watchers?

Rather than letting Big Brother choose books for us, we could establish
a democratic system with many librarians in many cities empowered to
make acquisitions. Never would bureaucrats be able to do the equivalent
of tweaking old copies of the _London Times_ behind our backs. It would
be too damn hard with so many librarians in so many locations, and with
the same material reposing on millions and millions of tablet-style
computers that individual Americans owned. My vision was one of
electronic federalism, not of Big Brother policing our reading tastes.
TeleRead wouldn’t undermine local schools and public libraries. Quite
the contrary. TeleRead would buy affordable, sharp-screened machines for
them, sending a signal to Silicon Valley and paving the way for similar
computers to go on sale at the Kmart for $99.95 for anyone to buy.

Just as important, unlike the Postal plan mentioned earlier in this
chapter, my TeleRead plan would let schools and libraries use the
hardware without Big Brotherish restrictions. They could store whatever
they wanted on their own computers for local people to dial up. And to
make the national library more useful at the local level, they could add
special, Web-style links designed for the people they served—not just
for whole communities, but perhaps even for individual readers.

What’s more, TeleRead would respect diversity and freedom of expression
in other ways. Publishers could gamble fees up front to bypass
librarians and qualify for royalties, and if censored from the national
library, they could post on the Net itself. I took it for granted that
Washington would try to censor TeleRead. That was the reason I
envisioned a whole network of many librarians, in many places, together
with long-range funding. Besides, my plan reflected the old wisdom from
hackers: When censorship arises, just route around it. Private companies
could make some nice money off officially banned books. Imagine the
promotional opportunities; “Nixed by Washington” could be the new
“Banned in Boston.” What’s more, since TeleRead was public and involved
many librarians, not just a tiny D.C. elite, any censorship would
probably be much more conspicuous than in the world of corporate
publishing.

In other ways, too, TeleRead would be anti-Big Brother. Americans would
not have to make private companies privy to their reading habits. The
national library could track dialups for the purpose of paying writers
and publishers—you couldn’t retrieve books without reporting past
accesses. But TeleRead would include protections. Records associated
with individual users could be temporary, just a way to prevent
information providers from abusing the system with repeated dialups.
People could buy controversial books by way of anonymous digital money.
In fact, with sophisticated enough fraud controls, the same techniques
might eventually be used to prevent names from being associated with
dialup records even for a short time. If nothing else, people could
entrust TeleRead records to certified private companies that reported
accesses without revealing identities.

TeleRead, then, could provide even more safeguards than public library
records in the paper era—significant, since librarians by habit had
respected privacy much more than had other government officials. “There
was a case back in Nixon’s era,” Phil Zimmermann would eventually remind
me, “where Nixon tried to find out what some of his enemies were reading
at the library, and the librarians were, of course, up in arms about
being asked to supply a list of books that had been checked out by a
particular person or a list of people that had checked out a particular
book. They were able to resist the efforts by the government to obtain
that information. I think that we need to have the same kind of controls
in place for future libraries that are on the Net.” I couldn’t have
agreed more.

Even the hardware could serve to thwart Big Brother by promoting free
expression and democracy. TeleRead would let people talk back to
bureaucrats and among themselves; the machines would work with
keyboards, and someday they might even serve in part as wireless digital
telephones, not just computers. TeleRead would let Americans all be more
uppity. The information in the national library would enrich public
debate; it would at least somewhat blur distinctions between the wealthy
and those who otherwise couldn’t afford top-quality information.

This needn’t be just a dream. The United States had a $6-trillion-plus
economy, and if just some of us used electronic forms for government and
commercial transactions, we eventually would save tens of billions in
time and money. As noted earlier in this book, the same pen interfaces
that were ideal for reading would be great for forms. E-forms could help
flag errors in tax returns and other documents, “interview” users
quickly, and just as quickly narrow down questions to the essentials.
And so the saving in time and money could easily justify a well-stocked
national library. No magic was involved here, just an old principle of
information management. Two applications (smart forms and the electronic
books) made more sense than just one (the books). In fact, the American
Society for Information Science would later approach me to do a chapter
on electronic libraries for an ASIS book from MIT Press, and I would
oblige. Clearly TeleRead was a logical link between Gore’s plans for
reinventing government and his oft-claimed desire to drive down the cost
of knowledge.

I was a writer, not an attorney or information scientist, but a number
of well-credentialed people understood the logic of TeleRead, even when
I showed them a version somewhat less refined than the one just
described. At the urging of a distinguished Washington lawyer, I applied
to testify at the interagency hearings on intellectual property law in
the digital age. But he warned me some bizarreness was afoot. Experts
from the Library of Congress would not run the hearings; nowadays
electronic books would be more within the domain of the Commerce
Department. A Commerce bureaucrat instead would be the main player
here—Bruce Lehman. That should have been my tip-off that the proceedings
would be big and furry and jump, and come with a pocket for joeys; but I
went ahead just the same. The lawyer organizing the hearing seemed
friendly, alert, intelligent, receptive. She said each witness would
testify just a few minutes, and that after the hearings the Feds would
carefully examine our words.

My optimism grew. I expected at least a modicum of electronic democracy,
Gore-style, just as promised. So in November 1993 I joined some thirty
other witnesses in Crystal City, Virginia, across the Potomac from
Washington. Bill Clinton wanted his presidential cabinet to look like
America, and, in fact, a black man was secretary of the Commerce. Gazing
around the room, however, I saw a sea of white lawyers in dark suits,
along with a scattering of women in power clothes. I could have been in
California at an elite convocation of the software and entertainment
industries.

I ran into one of the members of the intellectual property group, a
minor White House advisor named David Lytel, who had promised to read my
proposal as sent to him on the Internet. Mr. White House didn’t waste a
nanosecond. “This is like Hollywood,” Lytel said. “Not everyone can be a
star. We can’t use everyone’s idea.”

“I’m not here to star,” I said, “just to testify. Have you read my
proposal?”

He said he had seen the prepared testimony I had left at the entrance to
the auditorium.

“But what about the thousands of words I sent you on the Net? I thought
you’d have a look and—”

“Excuse me,” he said and moved on.

His Hollywood analogy would strike me later as all too apt, for this was
shaping up as a TV-centric NII that favored television and movies over
books. Al Gore later would not hold his grand information summit at the
Library of Congress; no, he would jet off to Hollywood and to a speech
punctuated by jokes with a comedienne.

There in the Crystal City auditorium, I saw a tall, gray-haired man
surrounded by a cluster of other people. Heads bobbed. Stephen Metalitz
was a lawyer and a power in the Information Industries Association, the
IIA. “Welcome, Steve,” Lehman greeted his first witness in a voice that
told me who the true star of the day was. The rest of the hearing
unfolded as I now feared. Witnesses from trade associations pounded away
at the same theme again and again. Copyright law needed to be friendly
to megaconglomerates or they would never bless the dataways with their
_Terminator_ films. It was as if the Internet, already starting to
bristle with small businesses, never existed.

I heard some cogent testimony from some fine people representing
librarians and educators, but all in all, I might as well have been at
an IIA convention. Lehman’s panel of bureaucrats, some of them strangers
to copyright law, just about dozed off during my testimony. Chatting
with me informally, certain industry witnesses were more curious about
my ideas than were the Feds. It wasn’t just to size up the opposition.
For my plan would divert resources from bureaucracy to knowledge, and
could actually _help_ many members of the information industry.

A potential obstacle rose ahead, though: the hostility of real, live
bureaucrats.

During a break I approached a working-group member from one of the most
bureaucratic agencies of them all, the General Services Administration.
“What do you think of my ideas for electronic forms?” I asked. “I
remember when you guys let a senator benefit illegally from a federal
lease on an office building. Imagine what you could have done with
better technology to help flag stuff like that.”

“Oh,” he said coldly, “we can just train our contracting officers
better.” Better to protect jobs for bureaucrats like him than to offer
affordable e-books for schoolchildren.

My foremost opponent, however, as I learned eventually, just may have
been Lehman himself—the chairman of the Intellectual Property Working
Group, which would help set copyright policy for America’s dataways.

Bruce Lehman was Mr. Politically Correct. As his heroes he claimed the
career-enhancing names of Bill Clinton and Martin Luther King; never
mind the damage that his child-hostile copyright policies might do to
ghetto schools, or the fact that the copyright hearing had been about as
well integrated as a Klan meeting. The _New York Times_ would see in
Lehman’s office “a handsomely framed photograph taken at last year’s
White House Christmas party. Bill and Hillary Clinton stand in the
middle. Mr. Lehman is to the left, under a portrait of George
Washington.”

His clothes were as aggressively fashionable as his choice of heroes.
The _Times_’s Teresa Riordan would write of “stylish suits detailed with
a fresh white handkerchief.” He might display “a touch of exotic color,
perhaps a mint-colored watchband or the ruby background of a Brooks
Brother tie.”[6.37] Lehman needn’t haunt any thrift shops. During a
twelve- to fourteen-month period before joining the Administration, he
had pulled down $430,000 as a lobbyist and lawyer for intellectual
property clients.[6.38]

The patent office’s Web site said he had represented “individuals,
companies, and trade associations in the area of intellectual property
rights as it affects the motion picture, telecommunications,
pharmaceutical, computer software, and broadcasting industries.”[6.39]
His clients had included Lotus and Microsoft.[6.40] The latter was
buying up electronic rights as if they were soft drinks for the
programmers’ offices. No, Microsoft would hardly be the world’s leading
backer of a universally affordable, well-stocked national digital
library of the TeleRead variety. I’d lobby anyone, any company, for my
idea. But could I ever persuade Microsoft? Oh, come on. This was the
company that owned the word “Windows.”

Clinton-Gore campaigners had once talked of “People First.” Based on
Lehman’s background and proclivities, however, a better motto in the
case of intellectual property might now be “Entertainment, Information,
and Software Magnates First.” It was as if Clinton-Gore had turned
national health policy over to a zealous insurance lobbyist who had
spent years crusading for higher premiums.

Even at the local level, Lehman was no stranger to the world of money
and politics. In 1991, while a Georgetown lawyer, he had lent $10,000 at
12 percent interest to Washington city council candidate Jim Zais even
though local law apparently restricted candidates to borrowing only from
the usual lending institutions. Zais at the time had raised less than
$13,000 from other sources. Questioned by election officials, the
candidate had claimed ignorance of the law and promptly paid the money
back to Lehman, along with some $120 in interest.[6.41]

Like many of his ex-colleagues at Swidler & Berlin, Lehman had kept his
checkbook wide open when national politicians needed money. Many months
later I learned that between January 1, 1991, and November 28, 1994, the
S & B crowd had made at least $191,000 in political donations, including
more than $22,000 from Lehman himself during his days there. At least
$146,000 of the $191,000 had gone to the firm’s political-action
committee. Lehman’s personal contributions had reached at least eighteen
congressional candidates. In fairness, let me emphasize that Lehman
didn’t just have direct career considerations in mind—he was the first
openly gay man whom the U.S. Senate had confirmed as a top federal
official,[6.42] and he had given generously to gay political-action
committees.

Gay groups, in turn, showed their loyalty. They had wanted Clinton to
appoint Bruce Lehman to _something_, and the White House had made him
patent commissioner even though Lehman knew more about copyrights. Ron
Brown, however, secretary of Commerce, said: “Bruce Lehman is not here
because he’s gay. He’s the absolutely best person for the job.”[6.43]

I believed Brown. If the Clinton Administration wanted library interests
to be kept at bay to placate rich campaign donors, Gore’s dreamy
rhetoric notwithstanding, no one would beat Lehman the ex-lobbyist.

A few weeks after the intellectual property hearing in Crystal City, a
letter arrived from Mr. Reinventing Government himself. I had mailed my
TeleRead proposal and a related _Washington Post_ clip to Al Gore many
months ago in spring 1993, and now he replied: “I am impressed with this
detailed and very professional presentation. The information you
provided certainly appears to contain ideas that merit careful
attention. I will retain this material for future consideration as the
President and I work on related policies and programs.” I hardly
expected a meeting with Clinton and Gore. But was it just possible that
one of their GS-14s might deem me worth five minutes of time, and follow
up with a few questions?

Months passed. An occasional reporter or academic would read my
testimony and call or e-mail, but no one phoned from Commerce.
Meanwhile, seeing my TeleRead proposal on the Net, major vendors
contacted me. Often they asked the big question: “How are you doing in
Washington?”

“Well,” I said in effect, “I hope they’re keeping an open mind.”

“That’s nice, bye,” the answers would more or less come back—assuming I
heard again from people at all. The NII wasn’t just TV-centric. It was
Gore-centric. If you lacked his blessing, and his bland letter to me
didn’t count, you were dead or at least comatose unless the right word
from the White House revived your idea.

Then a “Green Paper” revealing the Clinton Administration’s preliminary
views on data highways and copyright came out. It was even more horrid
than I could have imagined, an insult to the memory of Andrew Carnegie.
The ethos was exactly the opposite of TeleRead’s. For example, if the
paper became law, one could not transmit a newspaper article to a few
friends; the present ambiguities here would be resolved in favor of the
copyright holders. Yes, Washington should not allow anyone to bootleg
newspaper stories or magazine items for hundreds of people in an
electronic discussion group. In fact, I’d once reported a gross offender
to a magazine; I believed passionately in property rights. Clearly
electronic books, of all media, should enjoy protection, which, in fact,
TeleRead would promote by making piracy less lucrative. But we also had
to understand the purpose of copyright law—to help spread information in
a democracy and further the progress of science and the arts. Lehman
either was disingenuous or had let his old $430,000 make him a little
amnesic toward Constitutional tradition.

Ironically, if Lehman’s side won out, writers and journalists would be
among the biggest victims of the very law designed to protect us. After
all, we were not just producers of information; we were also consumers.
To write a book I would absorb millions of words from the Internet,
swapping information with friend after friend along the way, including,
yes, some electronic newspaper clips. But the Green Paper bizarrely
flouted the natural tendency of most people to _share_. Imagine the
effect on teachers and children. Quite rightly, Jim Warren observed that
Washington was cheating the public “to avoid controversy among
‘important’ people.”

“The Draft Report comes down firmly on the side of increased rights for
copyright owners in all relevant contexts, endorsing the goal of
enhanced copyright protection without acknowledging any countervailing
concerns,” wrote Jessica Litman, a law professor at Detroit’s Wayne
State University. In a reply to the Administration she said of the
report: “It appears to be an advocacy document: It at times
misrepresents the state of current law, and gives voice to only one side
of complicated policy debates.”

Another expert, law professor Pamela Samuelson at the University of
Pittsburgh, lambasted the Green Paper in an article for _Communications
of the ACM_, published by the Association for Computing Machinery. She
said that “not since the King of England in the sixteenth century gave a
group of printers exclusive rights to print books in exchange for the
printers’ agreement not to print heretical or seditious material has a
government copyright policy been so skewed in favor of publisher
interests and so detrimental to the public interest.” Contrary to
Washington’s claim, the Green Paper was not just a tweaking of existing
law but a radical revision in favor of publishers.[6.44]

Directly Orwellian questions arose. What about enforcement? How to
thwart the ease of mailing copies over the Net? The Green Paper’s
designers thought that laws against circumventing copy protection would
provide one of the main answers. But in the case of electronic text,
such visions were far too sanguine. People would want the capability to
print out material, and if they could print it out, they could scan it
and put it online again without the protection feature; what’s more,
hackers would inevitably develop software to accomplish the same thing
electronically.

Yes, the Green Paper would let publishers and others sue makers of
devices that could get around copy protection. But just what gear was
covered? Scanners? Fax machines? And what kinds of software? What about
legitimate programs that also had illicit uses? Were we the new Soviets,
living in fear of the digital equivalent of copiers and other subversive
gadgets? As William Buckley would write, “fax machines and e-mail
outwitted and frustrated even the comprehensive revolutionary orders of
Stalin and Mao. This side of what used to be the Iron Curtain, we should
have the resources to handle our native bureaucracy.” The Green Paper
was nothing more than Big Bureaucracy trying to serve Big Business.

The Green Paper had much in common with Clipper. In both cases
bureaucrats were reducing respect for Washington by trying to control
the uncontrollable. I was hardly a kneejerker crying out for a
pigmy-sized government. My liberalism remained. I favored prenatal
nutrition programs, Head Start, public broadcasting, and a host of other
wonderful anachronisms from the heyday of the Democrats. And yet here
was the Clinton Administration blundering along in the most obnoxious
way and turning so many of my fellow liberals on the Internet into
libertarians.

If nothing else, the White House was complicating my job of trying to
sell the Net on TeleRead. It was not just a question of preempting my
idea in favor of an inferior solution rigged up for Clinton’s powerful
friends in entertainment and publishing. Like Clipper, the Green Paper
was lessening faith in Washington, period—no small concern for somebody
advocating a national program such as TeleRead, even one developed with
local sensibilities in mind. Sometimes I wondered if Lehman might be a
Manchurian Patent Commissioner.[6.45] Had the Libertarians brainwashed
him to sully Washington’s good name?

Again and again I flamed Lehman’s Green Paper on alt.activism and at
least half a dozen other newsgroups on the Internet. I hadn’t any
choice. He hated the bytes-want-to-be-free philosophy of TeleRead.
Clearly, if Lehman had read TeleRead, it would have driven him nuts,
given his apparent belief that copyrighted books must _cost_ readers.
TeleRead, on the other hand, would mean fair treatment of copyright
holders and library users alike. With a TeleRead-style library,
publishers, writers, and private nets could still charge for many
categories of information and earn handsome sums from online conferences
and other services and products, including customized software to guide
people through electronic libraries. Also, they would receive fair
royalties for covered material such as books. At the same time, however,
thanks to the cost justification provided by the e-forms, we could make
electronic books free in this TV-fixated era and thus encourage
literacy.

Surely TeleRead could be a logical link between Gore’s plans for
reinventing government and his oft-claimed desire to drive down the cost
of knowledge. With TeleRead, the old scarcities could be obsolete; rich
and poor could dial up the same books. It would be a far cry from the
present when Beverly Hills spent many times more on library materials
than did some poorer jurisdictions. TeleRead was not a cure-all; but in
an era of tight budgets, the national library could be phased in
carefully, year by year, topic by topic, with minimal pain. The
reduction of expensive, onerous paperwork would be like a tax rebate.
For once, a program could simultaneously help schoolchildren and small
business people.

Perhaps the NII Advisory Council would see merit in TeleRead. The White
House didn’t necessarily have to follow its recommendations, but wasn’t
this the age of electronic democracy and citizens’ input? A few problems
had arisen, however. Bill Clinton’s people had tolerated just one
librarian among the more than thirty members of the Council. An
overworked teacher was there representing education. But no full-time
professional writers of books, and just one newspaper publisher, had
ended up tainting the Advisory Council.

Nor did any name show up from a distinguished publishing firm such as
Knopf or Farrar, Straus and Giroux. Instead the White House blessed the
NII with Vance Opperman, a friend of Al Gore’s and a money man for the
Democratic Party,[6.46] who was president of West Publishing. By one
estimate West grossed some $600 million a year with pretax margins of
almost 30 percent, or twice those of rivals.[6.47] West-style firms were
famous for Cadillac-priced data. Opperman’s company had set up
collections of court opinions and slapped a proprietary system of
citations on them. The meter typically ran at $4 a minute or more,
adding up to millions from Feds and taxpayers alike.

Haunted by a group called the Taxpayer Assets Project, the Justice
Department had proposed an electronic database with public-domain
citations to help users locate material. But West had lobbied away the
plans. Nothing must deprive Al Gore’s friend, and so many other
politicians’ friend, of a chance to turn a buck. Opperman seemed about
as eager to drive down the cost of knowledge as Bull Connor was to
further civil rights in the days of cattle prods and police dogs.

At the same time the Advisory Council teemed with people from such
library-like outfits as CBS, Black Entertainment Television, and Walt
Disney. Bill Clinton’s people also let the movie industry’s premier
lobbyist sit on the council—Jack Valenti, a former aide to Lyndon
Johnson; yes, the same Valenti who had made history years ago by
sleeping better at night because, he said, LBJ was in the White House.
To the Council, too, went powerful telephone executives, a man from
Microsoft, and John Scully, the former Apple executive who had been a
Clinton stalwart in ’92. A co-chair was a Clinton supporter named Ed
McCracken. He came from Silicon Graphics, a billion-dollar company that
was hoping to make a fortune off the new video technology.

Clearly entertainment was what counted most here. The term National
Information Infrastructure just didn’t suffice. A more accurate
description, given the paucity of librarians, educators, and journalists
on the council, would have been the National _Entertainment_
Infrastructure. Yes, people like Vance Opperman were interested in
electronic text, but, above all, from a business perspective. Let the
masses watch TV. His company would make a fortune selling pricey
information to the elite.

Mass literacy just wasn’t the main show here, not with all the dutiful
suits watching out for the earnings of CBS or Disney or Microsoft or
West, and without enough librarians and others to balance them out.

A host of other issues remained. How fascinating that so many of the
most influential people in the Clinton galaxy were from outfits such as
telephone companies that wanted to profit off both transmission and
content. Despite all the rhetoric, I wondered how attentive the
Clintonians would be to, say, little companies that were more interested
in producing books or folk albums than in financing _Terminators_ or
laying fiber optic cables.

Could money and politics have mattered just a little in the selection of
people for the NII Advisory Council? If nothing else, a few questions
arose in the case of West Publishing, the giant publisher of legal
information. Vance Opperman was friends with Mack McLarty, Clinton’s
first chief of staff.[6.48] What’s more, Opperman cochaired the finance
committee during the 1994 reelection campaign of Dianne Feinstein, a
Democratic U.S. senator from California who sat on a copyright
subcommittee within the Judiciary Committee.[6.49] A study by the
Taxpayer Assets Project, one of Ralph Nader’s groups, revealed how
civic-minded West was. By way of a political-action committee and gifts
from lawyers, lobbyists, and family members, the West crowd in five
years had given more than $738,000 to Congress members and the
Democratic National Committee.

Judges, too, must have loved the company. A West-run foundation had
dispensed $15,000 awards to federal judges for “distinguished service to
justice.” Over a dozen years, the selection committee had included seven
past or present members of the U.S. Supreme Court, the ultimate
interpreter of copyright law. West had paid for trips to places as far
off as Hawaii and the Virgin Islands. Benefiting, according to the
_Minneapolis Star Tribune_, were Justices Anthony Kennedy, Sandra Day
O’Connor, John Paul Stevens, Antonin Scalia, and now-retired Justices
Lewis Powell, Byron White, and William Brennan.[6.50]

West impressed me. Via campaign gifts, friends, and favors such as the
trips, Opperman’s crew had cozied up to all three branches of
government—the executive, the legislative, and the judiciary.

Eager to see how representative West was with its people’s political
gifts, I phoned the Center for Responsive Politics, the Washington-based
group from which I simultaneously got information about Lehman. Would
the Center please send me a printout of congressional and presidential
donations from some other members of the NII Advisory Council and from
people and political-action committees associated with their companies?

A list arrived for the period between January 1, 1991, and November 28,
1994, and I scanned down the names on the laser-printed sheets. The Walt
Disney people hadn’t disappointed me. Advisory Council member John F.
Cooke, president of the Disney Channel, had given at least $48,000 to
politicians from coast to coast and to Democratic organizations.
Non-Council member Jeffrey Katzenberg, then with the Disney
conglomerate, had donated at least $63,000 in one way or another.

I saw _at least_ $400,000 in Disney-related gifts—donations from top
executives were just the start. Cook and Katzenberg on their own
couldn’t sway the White House and Congress, nor even could all of
Disney; but imagine what Hollywood and other rich industries could do en
masse to influence copyright and telecommunications policies. What
counted most wasn’t the person but the industry. At one recent gathering
at Steven Spielberg’s mansion—in spring 1995, a time not covered by the
laser-printed sheet—Bill Clinton had raised $50,000 per couple.

Whatever the case, the stray change added up. Over at MCA, Advisory
Council member Alvin Teller gave at least $28,250 between early 1991 and
late 1994, while Lew Wasserman, a nonmember, gave at least $87,000.
Advisory Council member Jack Valenti, Hollywood’s big lobbyist in D.C.,
donated at least $56,250.

Advisory Council member Stanley Hubbard, chairman and chief
executive of Hubbard Broadcasting in Minnesota, also made a good
showing. He and relatives gave at least $74,000 to people on the
Hill, political-action committees, and the Democratic Party.
Confronted with $1,000-per-election limits on political gifts to
members of Congress, Hubbard just spread his money around, as if
using greenbacks like calling cards. His donations reached powers
such as Representative Ed Markey of Massachusetts, who, until the
Republican victory in 1994, chaired the House Subcommittee on
Telecommunications and Finance. Many saw Markey as one of the more
progressive NII players. Just think, however, what such politicians
could have done without the distractions of special-interest
money—donations not only to them but also to colleagues who would be
more susceptible to pressure.

Telephone executives made the NII sugar-daddies list, of course.
Advisory Council member Bert Roberts Jr., MCI’s chairman and CEO, gave
at least $28,000 to an MCI political-action committee and to
politicians, ranging from Senator Bob Packwood to, yes, Edward Markey. A
supporting cast came from the ranks of the MCI employees, including one
of my techie heroes, Vint Cerf, “Mr. Internet,” who contributed at least
$1,000 to the same PAC as Roberts.

Advisory Council member James Houghton of Corning Glass donated more
than $50,000 to members of Congress across the country, and to party,
presidential, and PAC funds. Corning, of course, was rooting for
fiberglass cable—a rival in some ways to wireless technology, which some
on the Internet considered the future.

No, the millionaires on the Advisory Council had not committed crimes or
bribed anyone. Under the law, they had a right to give massive amounts
to campaigns as long as each gift did not exceed the legal limits. To my
knowledge no money had come from anyone’s corporate tills, just from
individuals and the political-action committees to which they had
lawfully contributed. Besides, just like Lehman, many other rich donors
must have had the most heartfelt of reasons for personal donations,
going far beyond copyright and telecommunications issues. Even though
copyright holders had donated to many well-positioned politicians such
as Senator Dianne Feinstein, who was active on intellectual property
matters, that was hardly the only reason why Hollywood millionaires
gave. The woman was a California Democrat. Many people at companies such
as MCA were the same. If a Californian, I myself might have voted for
her.

Likewise, the people of West Publishing must have had varied motives in
contributing.[6.51] Vance Opperman was a former antiwar protester and
probably still saw himself as a force for social good. I suspected, too,
that he loved seeing his old friend Al Gore grow in power. At the 1992
Democratic Convention Opperman had described himself as a “political
junkie” who enjoyed hosting political receptions for fun. “I don’t
expect to get any political benefits out of them.”[6.52]

Replying on February 22, 1995, to questions from the _Minneapolis Star
Tribune_, Opperman’s company noted that all donations were legal and on
record at the Federal Election Commission. “It appears that you believe
the laws regarding these matters should be changed,” West said. “If so,
the proper thing for you to do is to seek to change these laws rather
than criticize those who carefully comply with existing law.” The
company denied any efforts to influence officials improperly. West said
that its employees, its political-action committee, and its counsel all
had “long histories of being active in the political process. It is
inaccurate to tie their donations over the past 20 years to any specific
issue of legislation pending before a government body. Your inference
that such donations have been made as one collective effort is also
totally untrue.”[6.53]

West pointed out to the _Star Tribune_ that people from rival
information companies were also making contributions. But of course!
Money always counted in politics. Vance Opperman had put it well several
years ago as head of Opperman Heins & Paquin, a leading law firm notable
for PAC gifts to Minneapolis politicians. “If we have those who oppose
the interests of our clients,” he said, “we do not support them.” He
said the law firm’s PAC ran under this philosophy: “Support your
friends. Punish your enemies.”[6.54]

Presumably Bill Clinton and Al Gore would rather avoid punishment from
the Oppermans of this nation. While almost ignoring librarians and
educators, the Administration had appointed to its Advisory Council some
members of the elite who were already over-represented in the political
process. Did Vance Opperman, as a friend of Gore’s, really have to worry
about the Vice President reading _his_ letters? I wouldn’t have been
surprised if he had Gore’s private e-mail address. Just how many
electronic entreaties to the Hill, or to the Clinton-Gore area on the
Web, would it take to neutralize the little fortune donated by friends
of West Publishing? I couldn’t have agreed more with Cliff Stoll when he
wrote that Washington often ignored citizens’ e-mail. It all figured.
The Power People were too busy raising donations from millionaires and
political-action committees—hardly the biggest champions of low-cost
knowledge.

Granted, some optimists hoped that the Internet itself could help turn
around Washington. Aided by the Net, a group in Washington State had
gathered $26,000 to help defeat Tom Foley, then the Democratic Speaker
of the House. And NewtWatch, an anti-Gingrich effort on the World Wide
Web, had registered as a political-action committee. Some members of
both major parties were hoping to use the Net to raise money efficiently
from small donors.[6.55]

That was far from a full answer, though. Even before I learned of all
the campaign cash from some members of the Advisory Council, I had
wondered about the group’s odd composition. Not everyone on the council
was rich, of course, far from it. But why had business prevailed so
brazenly over the general public and Al Gore’s little neighbor back in
Tennessee, the one who was supposed to dial up books from the Library of
Congress regardless of family income? Just one teacher and one
librarian? In politer language I’d sent the question on to a White House
staffer, and he had patiently explained to me that Washington had to
serve the needs of the “stakeholders.”

I loved the word. It sounded so innocent, so natural, so philosophical.
What if this were eighteenth-century France, the revolution were on, and
Marie Antoinette looked like guillotine fodder? Armed with such a
marvelous locution, she could forego all references to bread and cake
and simply say, “Stop! I’m one of the stakeholders.”

Now having documented a nice flow of money from “stakeholders” to
politicians, especially Democrats, I remembered how many Watergate-era
ambassadorships had gone to the highest bidders. Wasn’t the same ethos
at work here as Richard Nixon’s? I knew of no broken laws—but perhaps
that was the trouble.

“I remember when I got on Energy and Commerce, everybody jumped for the
Telecommunications Subcommittee first,” Peter Kostmayer, a former
Democratic representative from Pennsylvania, said as quoted by veteran
political journalist Martin Schram. “There was a member sitting next to
me, and every time another member bid for that committee, he went
‘Ding!’—as if a cash register was going off.”[6.56] When politicians
talked about the need for election reform and clean, ethical government,
many were themselves superb examples of the need for action.

Maybe, I’d thought earlier, I could at least enjoy an open-minded
hearing from a nonmillionaire on the Advisory Council. Bonnie Bracey was
the only elementary school teacher. She should have loved TeleRead.

But during an official virtual conference organized on the Net by the
Commerce Department, she went after not Opperman but _me_. “I am not the
least interested in the TeleReader,” she said in a public message, “and
I don’t have any money after trying to do this job to invest anyway.” I
was and am a writer. Last I knew, I had not been selling computers.
Bracey needed to scrutinize my proposal. Maybe she could then dismiss it
as a nefarious writer’s plot. TeleRead did, after all, propose a massive
shifting of resources from bureaucracy to various forms of knowledge,
including—_gasp!_—electronic _books_.

At times, Bracey would e-mail me that my proposal intrigued her, but
somehow she would never get around to _study_ it, or at least to telling
me that she had gone beyond summaries. She would repeat the usual
clichés that citizens didn’t want to spend money on schools. Toward
TeleRead’s cost-justification mechanisms, toward the support that it
could win among frugal, business-oriented conservatives such as William
Buckley, she was unresponsive. Granted, she wasn’t callous about the
children TeleRead could help. At the personal level she had been
exemplary, spending hundreds and perhaps thousands of dollars on
hardware and software that she could use in her classes. But TeleRead
for her could have been a bother. Offensively, perhaps, it meant a
national library online for all, regardless of whether they happened to
be students anywhere.

TeleRead, however, was hardly antischool, given all the new
possibilities it could open up online for teachers and students. Looking
back, I just wished that Bracey had seen a note I received from a
teacher in Illinois who had asked more than sixty magazines for
permission to reprint articles for her small class at no profit. Only
twenty-five publications had gone along. “We were ignored sometimes,”
the woman had e-mailed me, “and once I was told, by phone, never to use
any articles from that publication. That was _Windows Magazine_, and I
didn’t renew my subscription.” Of her anthology, she had said: “It’s a
better textbook because it’s more up to date.” Clearly we could never
separate “educational” uses of the NII from the rest; an article from a
commercial magazine could actually prove so much more valuable than an
instantly obsolete textbook. TeleRead would make back issues of
magazines available for free, make current ones easier to obtain, and,
above all, allow free textbooks to be updated instantly, complete with
hypertext links to the rest of the national library.

But predictably the NII Advisory Council ignored TeleRead and more or
less green-lighted the Green Paper. The council for the most part came
out in favor of publishers enjoying control over transmission rights. In
effect these people were kissing off the idea of a comprehensive,
cost-justified library that all Americans could afford to use online,
whether for school or for self-improvement. As I was concluding this
book, it wasn’t certain that the Green Paper would slither its way into
law in more or less the original form. But the news from Capitol Hill
didn’t cheer me. The Republican Congress appeared to be at least as
skewed in favor of copyright holders as were the Democrats.

Even diluted (and renamed the White Paper in the final version), the
Green Paper might well be a disgrace. I worried about the rest of the
world. Imagine the Australians or Europeans looking to the United States
for leadership in Net-related copyright matters. To me, the Green Paper
bore the stains of greenbacks. People around D.C. had a polite little
word, “access.” It didn’t mean legal violations, but rather purchases of
policymakers’ ears. Information magnates had access. I wondered if the
little child in Al Gore’s hometown gave so faithfully to major
politicians, flew Supreme Court justices to Hawaii, and doled out
$15,000 “justice” awards.

The Green Paper, alas, was just one indication of many big shots’
willingness to work against the citizenry. Again and again the denizens
of Capitol Hill bragged about Americans being able to dial up the text
of proposed legislation through a service called Thomas. And yet some
Congress members still hoped to work out deals before the public saw the
results on the Net. Friends of West Publishing used exactly such tactics
on the Hill to try to reduce the amount of information that the
government released for free. West and similar companies wanted to be
able to profit off public data. So their congressional allies were
hoping to cancel out the Freedom of Information Act in cases where
federal contractors had created records.

Any weakening of the act would make me _very_ grouchy; it had opened up
many kind of government information for free or at affordable costs. I
had benefited. Two decades ago the General Services Administration had
tried unsuccessfully to charge me $20,000 to learn details about the
government’s office-leasing program. Using this first-class muck, I had
shown that then-Senator Abraham Ribicoff secretly owned a stake in a
building that the GSA leased for the Central Intelligence Agency. I had
learned, too, of a friend of Spiro Agnew who had been able to avoid
building a half-million-dollar cafeteria required by the lease for the
headquarters building of the Environmental Protection Agency. Because of
the Information Act, I had been able to report both stories and get them
out in the press and on network television. I had spent months camped
out at the GSA, perusing documents; imagine what I could have done with
a computer to ferret out digitized muck. And so I was dismayed to learn
that some in Congress wanted to weaken the Information Act—this in an
era when the Internet supposedly would open up Washington. If not fully
Orwellian, such hypocrisy didn’t promote democratic alternatives to Big
Brother.

Uppity activists used the Net to thwart West at least for the moment. A
bill introduced by Representative William Clinger, a Republican from
Pennsylvania, was to be heard in a subcommittee and rushed through a
committee edit in just a few days with West-friendly provisions. But
James Love of the Taxpayer Assets Project caught wind of the
shenanigans; Jim Warren pitched in with his own jeremiads in _Government
Access_, his online newsletter; and furious Netfolks called and faxed
the Hill. West may have really lost when the Republicans found out
through the Internet about the firm’s generosity toward the _Democratic
Party_, to which its executives gave far more than to the competition.
“Why are we doing this?” the Republicans, in effect, may have wondered.

Only because of some extraordinary diligence by Love and allies did the
public win here. Newt Gingrich could talk all he wanted about the Net
putting citizens and lobbyists on an equal footing, but without a
constant watch on the Hill, scene of so many crimes, the same power
cliques would keep winning again and again, banana-republic fashion.
West might yet succeed.

Around this same time, Sally Katzen, a top bureaucrat with Clinton’s
Office of Management and Budget had asked Congress to make certain that
the Feds could charge more for information in some cases than the cost
of spreading it. They would be able to do this after posting notices in
the _Federal Register_. And then, if insufficient protests ensued, the
info-gouges could begin. Katzen’s proposal didn’t fly, but its very
existence was bothersome enough. The idea hardly jibed with all the nice
rhetoric from the White House about using the Net to promote open
government. So much for freedom of information, Clinton style.

Meanwhile I forged ahead with my TeleRead efforts, perhaps not for this
Congress and this White House, but maybe for those in the future—once
enough voters understood that we mustn’t replicate online the “savage
inequalities” of our schools and libraries. TeleRead if nothing else was
a handy litmus test to find out which policymakers were sincere when
they talked about the need for true public libraries in cyberspace, as
opposed to just digital storefronts with links to publishers. Good
people could disagree with me. But when politicians and their flunkies
did not bother to hear me out despite my idea’s credentials, I was
reminded of how democratic Washington was toward Power People and how
oligarchic it was toward the rest of the cosmos. Sometimes I felt that
my location, in Alexandria, Virginia, was metaphorical. My apartment was
just inside the Washington Beltway.

The question of the moment wasn’t just one of copyright. It was also one
of democracy itself, both the decision process and the aftermath. What
about the Copyright Gestapo? In the future might the Feds monitor the
activities of Republicans more closely than they would those of
Democrats? Would Republicans be more susceptible to charges of
intellectual piracy when they did the inevitable and tried to share old
newspaper clips over the Net? Or vice versa? Would the Democrats suffer
discrimination? What about Italy, where the machine-gun-toting cops had
invoked software piracy laws against leftist bulletin boards but not
against conservative ones? But the Clintonians, so eager to serve their
political friends, were just as cavalier toward these possibilities as
toward the civil liberties risk of Clipper.

Ultimately the copyright-holders’ victory just might be Pyrrhic. Someday
the political terrain could shift and millions of children might grow up
on free, government-commissioned books. Or, perhaps instead, videos in
too many cases would replace text. So we were better off if, as soon as
possible, we used networks to spread _privately_ originated books
through a free, well-stocked library system. TeleRead could indeed help
many in the information industry. From Lexis-Nexis to Random House,
companies could turn profits off dial-up fees, either from works they
commissioned directly or from rights they bought from authors. TeleRead
wasn’t a threat to information companies if they truly added value such
as editing or marketing. Even West could benefit. TeleRead would let
Opperman’s company reap many millions off dial-up rights—not only to
legal writings but also to other kinds—if the market favored it.

No, the real losers would be the bureaucrats, whose work, after all,
would be less in demand in an era of electronic forms in mass use. And
even they could have a soft landing. TeleRead would hardly take place
instantly, and it would remove much of the scut work from the remaining
jobs in government. TeleRead was anti-bureaucracy, not anti-bureaucrat.
For the moment, however, as shown by the obtuseness of the GSA man at
the hearing, the resistance was there.

Some lessons were emerging. Hundreds of people had e-mailed me for
copies of TeleRead. “Even anti-taxers like me would be willing to foot
the bill for something so practical and knowledge infectious,” a home
schooler in Illinois had said. The head of the Digital Publishing
Association, an organization consisting mostly of small publishers and
writers, had loved TeleRead. “Instead of flooding the young mind with
yet another sitcom or soap,” he had said, “TeleRead would allow video to
present them with quality reading materials.” And yet our wishes had not
meant squat.

David Lytel, the White House staffer, may have pressed his delete key
almost as soon as the TeleRead proposal reached him over the Net. He and
his colleagues at the Lehman hearings hadn’t followed up my official
testimony with a single question in person or by phone or e-mail. The
hearings had been a big farce, a caricature of a public relations
exercise. I might as well have been Winston Smith deviating from the
plot and making a few friendly suggestions to one of Big Brother’s TV
cameras. No one would shoot or torture me for saying the wrong things,
but on the major NII issues the Clinton people were about as open as Big
Brother to ideas from below, Net or no Net.

I wasn’t the only writer with a few feelings on the subject of Executive
listening skills in this networked era. A _New York Times_ columnist
later told how cavalier the White House crowd had been toward the e-mail
from her. I’d actually gotten farther than she had. At least Gore had
sent me a higher class of boilerplate. Perhaps that was because I had
actually used conventional rather than electronic mail, and had enclosed
a photocopy of a TeleRead article from the _Washington Post_. Article or
not, however, the White House had thumbed its nose at me. While Clinton
and Gore couldn’t reply to every citizen, the composition of the
citizens’ advisory council had made clear what the NII priorities were,
even in the age of Cyber Socks: Big Government serving Big Business.

Clinton-Gore had better change if they wanted my vote in ’96. Rather
than just sharing Sock’s meows and feeling ever so smug about high-tech
democracy, they needed to spend time more listening to us nonlobbyists
and a little less time keeping Vance Opperman happy. Democracy should
not mean just a dialogue between the White House and the usual
“stakeholders.”

                  *       *       *       *       *

As is obvious by now, intrusive government officials love to fixate on
net.sex. But something else is happening as shown in the next chapter:
net._love_. Let’s hope that Exon and company can tell the difference.




                                CHAPTER
                                 SEVEN

    The Electronic
    Matchmaker


Gregory Smith* had yet to kiss Susan Olson* good night or run his
fingers through her hair. But he could do something else with his
fingers: type to her. Greg was a library and information-management
student in Adelaide in South Australia, she worked for a real estate
firm in Kansas City, Missouri, and they were carrying on a romance by
way of the Internet. “We write letters constantly,” he said, “and
exchange our thoughts on newspaper clippings, music, all manner of
things. About the only thing we haven’t exchanged are marriage vows.”

The outcome, as I began this chapter, wasn’t clear. If the Smith-Olson
affair was like many on the Net, they would pull the plug long before
all the typing destroyed their wrists. “For every good story,” Greg said
of love on the Internet, “there are at least 100 bad stories—people
meeting and realizing there’s a major difference between virtuality and
reality.” A few months later, I decided, I would check back in with Greg
and Sue and report the results at the end of “The Electronic
Matchmaker.”

For the moment I was optimistic. Greg and Sue had been at this for a
good two years; they spent several hours a day pouring out their
thoughts to each other, Greg at his UNIX workstation, Sue at her lowly
Packard Bell computer. He had bought her a diamond ring on a layaway
plan; she was giving him a ring. She would fly Down Under at some point,
and then the next summer, Greg would to go to Kansas City and meet Sue’s
family, including her father, a retired auto worker who, ah, had a few
surprises ahead.

I think of good people like Greg and Sue when I read the tacky, hacky
stories about unhappy affairs online and Net sex. While many
politicians and reporters delve into the sleazier areas of the
Internet—and, yes, regions can look like Silicon-era Sodoms—something
wonderful is also happening on the Net. It’s connecting lovers with
uncannily matched interests and values. Remember, the Internet teems
with more than 12,000 newsgroups. If you’re quirky and picky, if you
insist on a lover whose hobby is Esperanto, the international
language, try soc.culture.esperanto. If you want to find a fellow
Peace Corps alumnus, you can choose from among several newsgroups and
lists. If you’re a Libertarian stalwart and insist that your
girlfriend be nothing but—well, the search may take longer.

Some philosophies just don’t hold out as much appeal to women as do
others. But that has not daunted a smart young Libertarian in
California, Eric Klien, who started what may have been the Internet’s
first matchmaking service, an operation later taken over by Electric
Classifieds. Match.Com offers a long questionnaire that should appeal to
many of the detail-oriented habitués of the Internet.

Whatever your taste, the Net probably has a dating service if that’s
what you want. Operating with a French address on the World Wide Web,
Babb’s Personals shows up with a photo of a green-eyed, dark-complected
woman, and a number of free, anonymous ads in French and English.
Christie’s Internet MatchMaker claims to reach more than 14,000 users in
seventeen cities. On the Net, too, you’ll find HIV Positive Dating
Services (“Meet other positives, negatives, and neutrals locally,
regionally, nationally, and even globally”), Web Personals (“Now over
4,200 different visitors each day!”), and Virtual MeetMarket (“I believe
that the people who browse through here, and more importantly the people
who bother to publish personals here, are somewhat intelligent and
Internet-savvy enough to know the difference between FTP and FTD—you
know, the flower delivery guys?”).

I found some of the catchiest ads on Virtual. One showed a beautiful
twenty-five-year-old brunette in Los Angeles touching an empty set of
casual clothes labeled “Your picture here?” “I’m looking for somebody
who’s [_sic_] personality has a shelf life longer than a month,” she
said, and California spelling notwithstanding, she clearly deserved just
that sort of person. A graduate student, hungering for a “sweet SWM of
my dreams,” inserted a picture of a knight in armor. Seeking “a
Scandinavian beauty,” a graphics designer from South Carolina posted an
almost magazine-quality layout with photos of himself and his cats and
even an aerial shot of Charleston. The prose wasn’t the most
imaginative, and his Scandinavian requirement was rather limiting, but
in a flash the ad showed women what kind of life he could offer them.
Other possibilities exist on the Web. Instead of just saying you like
certain musicians or artists, for example, you might write Web links to
take people to an area with sound or graphics files.

The best matchmaker is the Internet itself, with all its ways of
bringing well-meaning people together. If Greg married Sue, this would
hardly be the first Australian-American marriage born on the Net.
Australia is the e-mail capital of the universe, or at least the
romantic regions thereof. Until surpassed by the United Kingdom and
Canada, Australia had more Net connections than any country except for
the United States. Recently the Aussies’ telcom people started charging
institutions for net connections according to the amount of use, and
that just might crimp future Gregs and Sues. But at least in mid-1995,
Australia’s e-mail laurels remain unthreatened.

American women love Australian men because they speak the same
language—more wittily than we Yanks do, of course—and because they all
carry huge knives with which they can defend their girlfriends against
crocodiles and muggers. Isn’t that so, just as in the movies? American
men worship Australian women because we know they are unappreciated down
on the sheep ranch, they’re literate, and have brilliant careers ahead
of them. Don’t knock stereotypes if they help bring the right people
together.

The film _Crocodile Dundee_ may or may not have been on the mind of
Laura Goodin when she was wandering through soc.culture.australian. She
saw “a message from an Australian composer studying in the U.S.,” who
told of “an alternative tune to ‘Waltzing Matilda.’” Laura asked for the
music. Within months the Aussie proposed, right over the Net in the same
newsgroup. “Congratulatory messages came from all over the United
States, Australia, and New Zealand.” Today Laura Goodin and Houston
Dunleavy are married and living together in the Washington, D.C., area,
with a baby on the way. They exchanged more than 1,500 messages during
their courtship, not to mention countless sessions of typing together in
Teletype fashion, just as Greg and Sue have done. It is not the same as
talking the old-fashioned way but can save enough in phone bills to pay
for an engagement ring or maybe a more powerful computer. “A
long-distance relationship is hellish,” Laura says, “but the pain is
eased somewhat by the Internet.”[7.1]

This isn’t just happening on the Internet itself. When a New York City
woman was testing a service that became America Online, marriage was the
last thing on her mind. Nevertheless she ended up married in Virginia to
a lover she met via e-mail. Rush Limbaugh, the conservative radio host,
met his wife on CompuServe, where, supposedly, she had sought his advice
on coping with a liberal professor. A chef and a substitute teacher met
on Prodigy and flew off to Las Vegas together, thinking they would enjoy
the video poker if nothing else; they won $4,000 and each other.[7.2]

A psychiatrist has even written a novel about online relationships,
_Virtual Love_. “E-mail has been called the singles bar of the 90’s,”
Dr. Avodah Offit told the _New York Times_. “And that concept intrigues
me a lot. The traditional ways that people meet now do not allow much
access to each other’s minds, and that has not led to enduring
relationships.” What’s the best place to find out about your potential
spouse? By sitting silently through movies or boozing it up in noisy,
smoky nightspots, or by sharing intimacies over the modem? “I find
people are more open on e-mail,” she says. And I agree.

The Internet, to be sure, is hardly a romantic nirvana, and although
this chapter will be positive about net romance for the most part, I’ll
mix the praise with some lengthy warnings. Some sections of the Net will
please fundamentalist preachers no more than will the red-light areas of
New York or Calcutta. From alt.sex.bondage I called up a digitized photo
fit for the Marquis de Sade. The caption accurately read, “Japanese girl
tied to rack while master pours hot wax on her breast. Looks very
painful and her face shows it.” Just about all of those posting to the
forum are male despite the heterosexual orientation of the typical
messages. This area of the Net is about as woman friendly as _Hustler_.
Offensively, too, the Internet also comes with sections devoted to
bestiality, and, yes, discussion of adult-child sex. In every case, of
course, society must distinguish between shared fantasies and real acts.
(As indicated in chapter 6, Exonian laws aren’t the solution—parental
vigilance and access-control software are.)

A more serious worry, from the viewpoint of women hoping for romance on
the Internet, is the locker-room attitudes that can show up even in some
respectable areas. Consider the cause of this: the numbers.

If you go by one network veteran, fewer than one in twenty of the early
Netfolks were female. By popular belief, maybe a tenth of the people on
the Net are female, a far smaller percentage than on other services such
as Prodigy and America Online. The truth, however, is a bit more
complicated. John Quarterman and Smoot Carl-Mitchell of Texas Internet
Consulting, which regularly tracks the demographics of the Net, reported
in the May 1995 issue of their publication _Matrix News_ that according
to a survey in October 1994, 64 percent of Netfolks were male and 36
percent female. And among educational institutions the percentage of
females was as high as 41 percent. Borders between the Internet and
commercial services are breaking down Berlin Wall fashion, so you can
expect the Internet to show an increasing amount of female influence.

The old stereotype, however, that the Net is male dominated, would seem
to hold up for the moment. Even the virtual dating services tend to have
far, far more men than women despite, in some cases, better terms for
female customers.

The reasons for the ratios are world famous. Computers in the past were
to girls what trucks and catchers’ mitts were also: the province of
boys. Thousands of men in the computer industry are still oblivious to
the existence of another sex. When I write popular-level computer books,
male editors often demand that I stick to the technology rather than
show how _people_ use it. Most women, however, recoil from the Internet
and other high tech unless they see practical reasons for bothering with
UNIX commands and similar horrors; they have been raised to favor humans
over gadgetry. Let’s hope that the old fears vanish as more women
befriend computers and programs grow easier for both genders.

Meanwhile, however, on some areas of the Internet, women can be treated
like females in Asian countries that pamper baby boys but all too often
let sickly girls die or even kill the fetuses. A few men ignore female
Netfolks except for purposes of humiliation, sex, or combinations of the
two. Although messages from women tend to draw more replies on the Net
than those from males, the end results can dismay; one man reportedly
welcomed a woman to a discussion group, launched a political dialogue,
then shifted in a nanosecond to a request for a swap of nude pictures.
Women tell of weirdoes stalking them via e-mail, flooding their Net
accounts with unwanted messages. One victim, as reported in _Mother
Jones_ magazine, suffered “an untraceable e-mail ‘bomb’ containing
hundreds of sexual and violent messages, the mildest of which was ‘Shut
up bitch.‘”

At the same time women on the Internet can enjoy less of the sort of
attention they desire. Some Netfolks don’t pay as much attention to the
public messages of women, and besides, female Internauts may not want to
post anyway in some areas, given the outright insults and sarcasm that
may await them. Women seek harmony and compromise; much of the Net
thrives on controversy.

My wife, who, like most of her gender on the Internet, hates flame wars,
has even run across a newsgroup whose people venture forth to start
arguments in other groups. What is a hobby to some men can be an
antisocial practice to women. Many women hesitate to speak up on the
Net, whatever the topic under discussion. Disturbing statistics come
from Gladys We, a graduate student at Simon Fraser University in
Vancouver, Canada. Writing in the magazine _Virtual Culture_, she says
at least four-fifths of several hundred postings to alt.feminism were by
men. She tallied figures almost as lopsided in soc.women. “Only in
soc.feminism,” We writes, “amid accusations of censorship, were there
comparable numbers of postings from women and men.”

Given the obstacles that women often face on the Internet, then, it is
amazing at times that _any_ romances happen there. When they do, yet
another danger arises—the risk of missed cues. A friendship online may
cause either sex to ignore mismatched words and gestures that might put
them on guard. One Los Angeles women met her boyfriend on a BBS and
suffered a disaster that could just as well have happened by way of the
Net. He got her pregnant, begged her not to abort, married her, and made
life a real hell, not just a virtual one, until they divorced.

Worrisome, too, are the eternal tensions that go on in cyberspace
between sincere Befrienders and not-so-sincere Gamesplayers, who the
former have trouble detecting. The Befrienders seek friends and lovers;
the Gamesplayers would just as soon toy with a human as hack a program.
An argument might even be made that high tech attracts more than its
share of people who thrive on impermanence. You do not last long in
computers if you believe that Pentium-level chips are forever, or that
28.8K-bps modems are more than throwaway technology in the general
scheme of things. Faster chips, higher speed modems, and new girlfriends
or boyfriends are sure to come along. That’s the mind-set. Let’s just
hope that the girlfriends and boyfriends will last.

“I am burning with a need to talk with you, to share with you my fears,
my joys,” one Australian women cooed via modem to a man in the Canadian
province of Alberta. Within two weeks her ardor did not just cool, it
inexplicably froze. “This is the very last time I will write to you,”
she said. Very possibly—we can’t say for sure without ESP—the Australian
woman was a Gamesplayer.

Gamesplayers enjoy at least one big advantage on the Internet. They can
post their electronic want ads through computers, known as anonymous
servers, that strip their names and other compromising identifiers.[7.3]
And replies can come through anonymous servers. The same technology used
to protect privacy can let Gamesplayers fool victim after victim, and
even mask genders. Particularly in fantasy games on the Net you can
never be sure if you’re typing to a woman or a man who just wants more
attention—abusive or not. What’s more, for the skillful there are ways
to forge messages to unsuspecting neophytes.

Another negative is that the Net can be as helpful to adulterers as to
the moral and sincere. A techie has just poured out to me a story of the
kind that Carson McCullers would have written if she had fixated on the
Internet rather than on the American South. His wife, the mother of two
children, has been using the Net to cheat on him in a massive way. She
befriended two alcoholics by way of her modem, the marriage counselor
says he has done all he could, and now comes word that she just might
have the AIDS virus; I hear it’s too early for a conclusive HIV test.

If sexual excitement is the only goal of _certain_ Netfolks, and if the
crowd in alt.sex.wanted is too creepy, some professional women just
might meet their needs. As noted earlier in this book, a little outfit
called Brandy’s Babes advertised on the World Wide Web—complete with
hints of more than just visual stimuli. The babes are apparently off the
Net now, but some would say that successors are inevitable. In _limited_
ways the Net and the world of professional sex are much alike: both have
their jargon and, for those who seek it, their anonymity.

Both worlds are rich in eccentrics. For example, I recently ran across a
woman in her late forties who was about to bear a baby with a computer
scientist she met on the Net “an hour before April Fool’s Day.” She says
the child was accidentally “conceived about two weeks after meeting ‘in
the flesh.’ We are having the baby first. _Then_ we will talk about
marriage on a serious basis. I’m delighted at the prospect of being a
mum at last, and I am not your average clunky woman at all. I generally
feel much better about myself. I introduced Tom to sex, and he says he
had no idea how cuddle-deprived he was. He’s now quite addicted to me.”
Tom and his computer are now part of her household; like many Netfolks
he can use his modem to work virtually anywhere, which in some cases is
yet another advantage of online romance.

Like most denizens of the Internet, the e-mail lovers just mentioned are
well educated. And, although the woman was between jobs, Netfolks are
normally at least affluent. If they are students, their parents are
middle class or better. While the price of Internet service is coming
down, and while access is free in some cities and at many American
colleges, the Net doesn’t exactly teem with welfare mothers.

So what other patterns emerge among lovers who meet through the Net? “I
haven’t done a study of the personality curve, the introvert-extrovert
ratio,” Avodah Offit, the psychiatrist who wrote _Virtual Love_, told
me, “but my experience is just the opposite of what one might expect My
‘high user’ contacts are all very sociable types who hate being out of
contact with others at any time of day or night. Of course my
correspondents are not generally engaged in romance with me, but they do
write to others online in a variety of relationships.” My own
observations suggest that while many net.lovers may be introverts, her
thoughts would hold true.

Judging from lovers whose photos I’ve seen, the plugged-in couples are
neither more nor less attractive than the world at large. But the
plainer ones can use prose to compensate for looks; this is a medium
where words are everything.

I hope that the people’s love letters don’t just vanish, because the
output of _some_ Netfolks can be charmingly Victorian in style, feeling,
or sheer volume. “My family took it pretty hard at first and were a bit
skeptical, especially my Mum,” says an Australian college student who
fell in love with an American more than a decade older than she is, ”but
then I gave them some of the early letters to read, a pile of 100, the
only ones I had time to print out, and the next day my mother came up to
me and said, ‘I am very happy for you. I am glad you have Frank.’ I was
waiting for the ‘But,’ but it never came.” A New England woman, who
married a fellow clarinet player she met on the Internet, says he once
showed her a $1,000-plus telephone bill. That’s Love, capital L. Maybe
the nineteenth century is alive in some quarters, whatever the medium,
voice or e-mail.

Below I’ll tell stories of Greg and Sue; a bachelor who was looking for
a woman who wouldn’t treat him like “a peripheral”; and a man who, to
his distress, found himself cuckolded more easily because his wife was
on the Net.

Greg and Sue

Adelaide was where Greg Smith majored in library studies at the
University of South Australia. It was a graceful port and state capital
with a Mediterranean climate, a population of a million, the Torrens
River in the center, and swarms of college students from three schools.
Named for Queen Adelaide, the wife of England’s King William IV, the
city dated back to the 1830s. Kangaroos still hopped around in the
countryside, but Adelaide itself was both urban and urbane. It was full
of churches and bars alike, along with trendy shops in Rundle Mall and
elsewhere. The State Theater put on Shakespearean plays at an
internationally known festival center.

Not surprisingly, Adelaide has been described as the Boston of South
Australia. While some young locals may shrug off the place as too
churchy and sleepy, others might disagree. Adelaide in many ways is a
young person’s town—a good place to meet the opposite sex. Greg Smith,
in fact, did find women in the corporeal world around him, but the
relationships never took root, and in the early 1990s he was still on
the lookout in the bars (“universities are great for this”), the parks,
the buses, the mall—you name it. He had his attractions. Greg, in fact,
was on the handsome side, if you went by the digitized photo and other
information conveyed over the Net. He stood six-foot four, weighed
around 190, kept in shape by walking, and had thick, dark brown hair,
and a winsome smile.

“I’m a physical person,” Greg told me. “I like to be with people. I like
‘reading’ people for body language and all that.” From the very start he
was aware of the perils and limitations of the Internet in such areas as
love. You had to trust the words of strangers, not sharing their own
reality. “Relationships are established where one party is totally
sincere and all that, and the other one is just getting a laugh out of
it.” Just the same, he could not resist touring the Internet and the
bulletin board to which his international connections led.

Young people like Greg Smith, who sought out new places on the Net,
whether bulletin boards or electronic libraries, were vaguely like the
Jack Kerouacs of the ’50s who liked bumming around the United States for
its own sake. Some would describe the high-tech Kerouacs as “net
surfers.” But the phrase “net surfing” has become so trivialized in the
media that perhaps we should return to the Kerouac analogy.[7.4]
_Kerouing_, not surfing. Stark differences, of course, existed between
the international Internet and the American towns of _On the Road_, the
famous Kerouac novel. Greg had spent some time in the United States when
he was ten years old and loved to keep up with American sports, but he
was very much a creature of Australia, with a distinctly Aussie flavor
in his accent and values. Nor was he a rebel in the true Kerouac
tradition. You could be a library science major and still soak up the
culture of the Net; you didn’t have to hop on and off freight trains and
risk poverty or a severed leg.

In fact, while hooked into an established institution such as a
corporation or a university, you just might do better than if you had to
buy all the gadgetry yourself—just so you didn’t flunk out while you
were partaking. A _teacher_ might even encourage your wanderings. And
that was how Greg ended up on the Net for the first time in 1992. He
found himself logging onto electronic bulletin boards all over the
planet, with bizarre names such as “Badboy’s Better BBS System” or
“Chatsubo.” He was at least partly drawn to such places because they
were so much like neighborhoods or small towns. Each came with its own
set of friendships, love affairs, and feuds that could reach an
intensity even greater than those on the discussion areas of the main
Net.

The woman who married Rush Limbaugh is said to have exchanged tart words
with Limbaugh on CompuServe at the start of their relationship, and the
same happened with Greg and Sue. They did not attempt an
alt.personals-style romance. Via Chatsubo he and she were just patterns
of dots on each other’s cathode ray tubes. In fact, the two even butted
heads over the question of whether certain people were abusing computer
resources.

Sue, it should be noted, was not a true technophile; she could fire up a
modem and use easy UNIX commands and that was about it. Even so, the two
shared much else. Greg was around twenty at the time, just a year or so
older than she was. Sue was a college student, at Northwestern Missouri
State University. “I like her intensity, her sarcastic wit, her humor,
and her, I dunno, just her way of seeing things,” Greg would say of the
Sue he came to know. “Politically we’re very similar, as regards
political policy and all that. Our tastes in music are close. Our
pleasures are drawn from simple, similar things. For example, we are
both mad about long walks, NFL football, curling up in front of fires,
walking in the mall, playing in the rain, and on and on it goes.” Sue
had been thinking about teaching, among other possible careers
(political work and diplomacy happened to be others), and she enjoyed
museums. Greg’s father had taught Shakespeare once, and his mother had
also been a teacher. So while nothing Oedipal was at work here, Greg
might well be more comfortable with a woman who shared familiar
priorities.

Just as important, both Greg and Sue could breeze along on a keyboard
and say _plenty_ online. In the near future, people might be able to
speak into a microphone with those at the other end seeing words pop up
on the screen, but for the moment the Net was friendliest to good
typists, especially those who could write well, as Greg and Sue could.
They could almost be playwrights, the way they loved stage directions
such as “Hugs” and “Wave good-byes.” If a feeling occurred to either,
they could transfer it from their brain cells to the keyboard and make
the recipient _see_ their thoughts. When Sue sent a letter to Greg and
me, it was obvious she wanted to get back to her private correspondence
with him. She ended her note: “*hugs greg* hold your horses sweetie, I’m
typing as fast as I can :-).” I could see that techie or not, Sue felt
at home at the computer keyboard.

Without trying to woo each other across fourteen time zones, the two
friends grew closer as they made the rounds of the BBSs on the Net. One
of the boards carried a gallery of digitized photos, and Greg enjoyed
Sue’s face. The look was American-Midwestern. Her light blonde hair
flowed in a way that must have pleased him.[7.5] She had green eyes
broken up with what she has described as a “strange shade of yellow.”
The skin was pale, the Scandinavian in her. In one of the shots she
posed with a knee resting on a well-padded armchair. She wore a
crocheted sweater, pants, and flats, and looked sexy but in a fresh,
friendly way that would not have threatened a schoolteacher’s son. Greg,
in turn, pleased Sue; in fact, even more so later on when she learned of
his height; she herself stood five-feet ten and favored tall men.

Sue especially relished his sense of humor. “I could log in after a
totally crappy day in classes and I’d have some corny e-mail from Greg
that would send a smile to my face no matter what I felt like. He was,
still is, and probably will be, the only person who can really cheer me
up no matter what the circumstances are.” Love, however, just wasn’t on
the minds of Greg and Sue in those early days. She had family and
friends in Kansas City and counted on braving the frigid Missouri
winters while she went to college. Meanwhile she had experienced her
share of romances off the Net, including one with a shy friend who
helped introduce her to the online world by suggesting that they _type_
to each other. Sue may or may not have been ready for yet another
relationship.

Even if she and Greg were just friends, they were paving the way for
something more by slowly trading secrets about themselves. Lois Shawver,
a California psychologist often online, warned me of the lack of trust
that can afflict many long-distance relationships via computer. And yet
paradoxically, the Net could bring people closer to each other. “It’s so
easy to end a relationship,” Shawver told me, “you simply stop
corresponding.” So “people seem to be more willing to take a chance and
disclose intimately. That helps to create trust. I do think that also
explains the medium’s ability to help people bridge cultural gaps.” It
was all certainly true in the case of Sue and Greg.

Helpful, too, was the emphasis that they placed on the platonic at the
start, without even meaning to do so. Is it just possible that horny
young men and women on the Internet and elsewhere could declare a
one-year moratorium on the raunchier forms of “cybersex” where men and
women exchanged lewd remarks with each other, Teletype fashion, in group
settings? Ditto for the online world’s many homosexuals and bisexuals.
Ironically the aftermath might be _more_ sex and better sex after some
true friendships developed by way of electronic mail and one-to-one
chats. One test of friendship, of course, might be this: Would a couple
still write to each other if their Net connection ended? And Sue and
Greg had passed so far: Her Internet account had vanished after she left
Northwestern Missouri State University to work and go to school
part-time. She ended up at an insurance company. Letters written on
pulped trees, comic strips, editorial cartoons, music cassettes,
material of all kinds, had traveled between Australia and Missouri. “We
got closer and closer with each postage stamp,” Sue told me, “and
believe me, there were a bunch. The post office likes me a _lot_.”
Finally, however, Sue had returned to the Net, this time with a private
account

On August 7, 1994, she had to break off an online chat to leave for
work. “And I had one more question for her,” Greg recalled. “She asked
what it was. And I asked her plain and simple, ‘Will you marry me?’
There was a pause of about thirty seconds, and she asked me if I was
serious. I said, ‘Yes, never more so,’ and she said ‘Yes.’” Sue let her
mother and a sister in on what was happening. She told certain friends,
too, but not her brother and father. “It’s just going to be
incomprehensible to them,” Greg told me, “that this could happen over a
chunk of cable. Add to that I’m stealing away their last child, not just
out of the home, or the state, but out of the country, and I can
understand why her father is not going to understand.”

The same shocks would presumably await Greg’s mum and dad. “I think it’s
more the medium than anything else. It’s way new to them, but for me
it’s just part of the way we do things now. *Grin*. Mum’s department
just got Lotus’ cc:Mail,[7.6] and she was telling me about it and I was
like ‘Yeah, so?’ but she was really excited about it.” Although Greg did
talk to Sue from home, not just his university, he could do so without
his parents knowing, because of the late hours he keeps, and because he
lived in a converted shed out back of his house. I pondered the ironies
here. Suddenly the Internet held out a new peril for parents. Having
fretted about electronic pornography, Mom and Dad could now worry about
children with more noble but equally secret activities. Parents might
erase porno from a hard drive; it was not so easy to wipe out love as
sincere and intense as Greg and Sue’s.

But had the two actually _talked_, telephone style, over a real phone?
“We’ve had a grand total of one phone call,” Greg told me. Sue dialed
him up. He said she’d kept putting it off because she was scared. “I
know, I know,” he wrote, “we should talk more but I’m just a poor
student.” Greg inserted the computer symbol for a smile to show he was
kidding. “The one thing that surprised me about that call was how
naturally the conversation flowed. I think it came from the fact that we
are friends first and a couple second—that the pressure of the
relationship was negated by the fact that we are such good friends. I
seem to recall impressions more than anything else, like the lilt of her
laugh, the timbre of her voice, the accent. We just talked about
stuff—us, love, Clinton’s screwups in Congress, sports, everything. Very
tough to put the phone down.”

“Still,” I asked Sue by telephone, “won’t it be quite a transition from
the American Midwest to Australia?”

In a friendly, steady voice she told how she had overcome her
hesitations. When Sue toured the local museums now, she saw graffiti on
statues, and she said the neighborhoods were slipping. I thought of my
grandmother’s old place in Kansas City years ago, how it had been
block-busted by sleazes who frightened the whites away and resold the
houses at handsome profits to Afro-Americans. Hotrods had roared up and
down Chestnut Street; Grandma had been the last white holdout. The
memory still enraged me. Although I hadn’t been to Kansas City in years,
I believed Sue.

“My brother and sister are quite a bit older than I am,” she went on,
”and they both have children of their own, and I’m not crazy about the
idea of leaving them to know their aunt through phone calls and video
tapes. But I have no intention of staying in the Midwest just for my
family’s sake.

“It’s my life and what I want to do requires more than the Midwest has
to offer. I can fit in well wherever I go. And I’ve gotten a few books
on Oz. From what I’ve read, I’ll like Australia just as long as I don’t
have to wear one of those damn hats and worship Paul Hogan. I have Greg
to worship. They may drive on the wrong side of the road and drink beer
with lunch, but it’s not like I’ll have to learn a whole new language.”
Besides, she loved the idea of the children growing up with an accent as
delightful as the one she heard from Greg.

I asked Greg if his virtual romance with Sue had changed him. “It’s
relieved a lot of the pressure that exists between myself and women,
because it’s no longer that I’m looking for something more than
friendship—I have a relationship which satisfies those needs and so
don’t need anything from those friendships. What is most interesting is
that change that I haven’t picked up but that other women must have. In
the two-and-a-half years I’ve been at the university, I’ve been ‘hit on’
a grand total of zero times that I can remember. In the twenty days or
so that I’ve been engaged, I’ve been hit on three times. And for the
life of me, I can’t figure out exactly what is making women see me as
attractive. And they weren’t friends or acquaintances either—completely
unknown to me. Weird.”

So how much had Greg changed Sue? “A lot,” she e-mailed back. Sue said:
“Being with Greg has taught me, if anything else, that my life doesn’t
have any boundaries, be they physical or emotional or geographic.” This
was more than lover’s mush; I noticed her use of “With Greg,” as if they
were in the same room.

Asked for love letters—no pressure, let me emphasize—the two obliged
with thousands of words just from their August 1994 writings alone.
Mostly the letters were from Sue whose feelings were more conveniently
preserved in digital form than were the letters from Greg. He wasn’t
holding back: He was the one who had contacted me about their romance.
What followed from Sue was more affecting than anything I’d read in a
novel, for it was real, and I learned about it in the same way that Greg
did, through a series of pixels on a computer screen. Reading this one
message would help explain why she was willing to leave Kansas City; why
she felt that, regardless of a father with heart trouble, she had felt
free to move on; perhaps even why she was willing to share her life so
openly with me through this book, for a chronicle was an affirmation of
sorts.

New to me but old to Greg, the revelation did not come immediately.
Sue’s August letters started out mainly with the routine, the glue of
long-range relationships, the confirmation that she wanted Greg to know
her life and likes. There was talk of food (“I love you more than I love
munching on peanut butter and crackers”), diets (“I splurged on Chinese
and probably regained the three pounds I lost”), art (at the Nelson
museum she favored the impressionists), friends’ babies (“Barbara went
to the doctor this morning to check and see how the baby was doing—she
was about ten weeks along, and she had a miscarriage”), school (Sue was
attending community college and could not resist sharing a few
unabashedly corny jokes about her anatomy course), places to go on
vacation (“Hey,” she said, in a discussion of Mount Rushmore, “do you
Aussies get weird and chisel the faces of dead leaders onto
mountainsides, or is that a distinctly American thing to do?”), and jobs
(“this working full time and college at night is starting to wear me
down a bit, but for the time being it’s what I want to do”).

Like almost any woman she _planned_. The word was that Greg should wrap
some paper around his fingers and snip it off at the right place and
send the results on to her so she’d know the size of his ring. And
should it be silver or gold? They discussed pajamas. “I always thought
it would be cool to share a pair of PJs with someone,” Sue wrote. “I’d
wear the tops, you’d get the bottom. Okay, so I’m cheesy, but I guess
it’s the American upbringing :). Shrug.” In her mind Sue saw the “really
cool chapel in Rapid City, South Dakota, where my grandparents on dad’s
side renewed their vows for their fiftieth wedding anniversary.” “I
wanna get married in it,” she wrote Greg. “There’s a place where you can
light a candle for a loved one and say a prayer to keep them safe. Well,
I lit a candle for Barbara, and then I lit one for us. It felt weird to
be in a church for a good reason. Seems that all the last ones have been
for funerals.”

Another close friend had died some time back, and she reflected on the
connection between that and a period of heavy activity on the bulletin
board circuit. “When I logged on, I could just be some faceless
person—no one had to know that my best friend was in the hospital room
semicomatose because he had developed full-blown AIDS. There were so
many people in my life that just up and left because Ralph* got sick; it
was almost as if I had AIDS just by association. So I got online and
became everyone’s favorite sweetheart.”

Then a signal fact emerged in the correspondence, something that
explained who Sue was, and why Sue felt like Sue, although I believed
that she and Greg would have wanted to be together even if her
circumstances had been different. “I had just found out,” she told him,
“that I had won a fight against a terminal illness while Ralph was
losing his. I don’t talk about the fact that I am a cancer survivor very
much, because I haven’t been in remission that long. It will be two
years in September.

“All I want to do is make it to the five-year mark and forget the pain
and the tears and the chemo and the treatments,” the letter said. “I
want to look forward and be able to see a future without constant trips
to the hospital, to days and nights when I can just be healthy and
happy. I have a tendency to block out when I was sick because if I don’t
think about it, I don’t remember it, and if I don’t remember it, I don’t
worry about it coming back. If you ask, I will tell you everything.”
Very early on in their friendship, Greg had known that the cancer was
cervical; any children would have to be adopted. Sue ended the message
by assuring him that she no longer wanted “the foreign policy degree
from Georgetown anymore, or the chance to have the President asking my
opinion on things.” Her goal now was Greg, an affordable flat, and a
roomful of kids to teach.

The rest of her letters went on to discuss such cosmic questions as
Sue’s love of long showers in the mornings, her tendency to roll around
a little in her sleep, and Greg’s hatred of his cataloguing duties.[7.7]
“I love love love love love you,” he wrote, and heated up the wires some
more while he and Sue dreamed of hugs at the airport, unstoppable
passion, and a wedding.

“Know,” he told her, “that there’s a goofy, tall, dark, Australian,
madly-in-love man here dreaming of you, and us, and the future.” I was
betting right now that they’d make it to that South Dakota church.

Lee Chen: The Lover as a Peripheral

He was a hacker, a true denizen of the Internet, and a poet at times.
A word in one poem told all: “peripheral.” It means a printer, a
modem, a scanner, or any other gadget that plugs into the main
computer, yet is not one of the _very_ most important parts. And
that’s how some women on the Net saw him, the human equivalent of a
printer, someone on the peripheries of their minds. He was among their
friends but not their lovers. His own love went unreturned. So he
called his poem “Song of a Peripheral”; he posted it to alt.romance,
soc.couples, alt.support.loneliness, and alt.support.shyness. It read,
in part:

 _You feel you’re nothing special in her life.
 You never get a sense that she wants you to be close to her.
 You’re just a pleasant, polite friend around the periphery of her world.
 But you still care for her, because she is that special woman—_

 _A sweetest heart who cares for the well-being of others.
 A most sensuous soul who is full of life and passion.
 And a beautiful intellect who brings realist precepts to balance out
    those disillusions in the world._

 _... It’s painful to feel you’re just a Peripheral, isn’t it?_

“How could I _not_ print part of ‘Song’ in this chapter,” I thought, and
wrote Lee Chen for permission. Back came a letter from the Department of
Computer Science at the University of Calgary in Canada. People on the
Internet love to end messages with “signatures” telling how they see the
cosmos, and Lee had picked a quote that looked as gentle and logical as
his poem. The speaker was the President of the United States in the
movie _Dr. Strangelove or How I Learned to Start Worrying and Love the
Bomb_. And the words went, “You can’t fight in here, this is the War
Room.”

Sometimes I thought that in the battle of the sexes, certain areas of
the Internet could be that war room. No man could claim to be a
superhunk or millionaire without risking a female retort in the vein of,
“Yeah, sure.” The Net was rich with put-downs worthy of an old
Tracy-Hepburn movie. Clearly the men had started this war, however.
“When a female shows up,” said the author of an explanatory file on
alt.sex.wanted, “clueless folks tend to e-mail ‘wanna fuck’ messages no
matter _what_ she has said. This means many of them don’t post, only
listen.” Fights had also broken out between the gays and certain
heterosexuals, who came up with the witless fag jokes, and who, in turn,
had drawn equally stupid remarks about “breeders.” In this sexual war,
the biggest losers were SMHGs. That was Netspeak for Straight Male Horny
Geeks, who, as noted earlier, suffered from the laws of supply and (lack
of) demand.

Lee Chen was an SMHG in a nice way. His style had been to try in
alt.personals rather than one of the tackier areas. When Lee had placed
a recent ad, he had described himself as “a romantic dreamer,” and he
wanted “a single woman between the ages of nineteen and thirty-three who
is sincere, intelligent, attractive,” and “passionate” as well. Lee was
twenty-six and entitled to feel his age. Moreover, based on his
self-description, women would have no more reason to run away from him
than they did from Greg Smith in _his_ lonely days.

“I’m five feet eleven inches, 185 pounds, have dark brown eyes and short
black hair,” Lee said. “And I’m a healthy, disease-free nonsmoker and
considered attractive looking.” He told me he held a master’s in
computer science, was continuing his studies, and obviously was destined
to earn a comfortable living at the very least. Lee enjoyed “going out
to movies and romantic dinners, discussing current events and politics,
visiting museums and natural parks, walking along the rivers, listening
to various kinds of music, giving and receiving pleasures with a
sensuous partner.” So far, however, Lee lacked a woman—he was new in
town. Maybe a minor part of his problem, at least among females off
campus, was the kind of place that Calgary was. He saw it as “a cowboy
city, big in the oil business, very similar to Dallas culturally, except
for the cold winter climate.” This particular SMHG might have felt more
comfortable in a more intellectually minded city such as Boston or San
Francisco. But he was no snob and still held out hope of meeting one of
the locals rather than confining the search to university people (“I’m
sure there are many wonderful women in this town”). Simultaneously he
decided to try the Net.

The first time out with a personal ad, Lee heard from a woman in, yes,
Australia—E-Mail Central. Dozens of love letters threatened to melt down
any fiber-optics on the Net; in fact, she sent Lee her erotic poetry and
encouraged him to reply with the same. Through it all, he was high
minded. “I believe in the mutual respect between women and men,” he
said, “but am also saddened by the gradual decline of romantic chivalry
in our society. I feel they don’t need to be mutually exclusive.” His
poet in Australia seemed to feel the same. Within a month she promised
to fly to Canada.

“My darkest knight, my love,” she called him. She was “burning with a
need to talk with you, to share with you my fears, my joys. I ache to be
able to brush a falling raindrop from your cheek and hold your handsome
face close to my heart. I miss you already though we have not met.”

This woman could have been crafting bodice-rippers for Harlequin Books.
“I thrive on every word that falls from your sensuous lips,” she wrote
Lee. “I feel I am being too bold for a lady of my breeding, but what I
feel has gone from my control before I was aware of my feelings.” More
letters followed, more fire, more steam. And then, out of nowhere: “This
is the very last time I will write to you. You have to leave me alone.
Any future mail you send me will remain unanswered. We do not know each
other. Words across a net aren’t a firm basis of a relationship and it
takes time to form a friendship. We have neither and I cannot currently
give either to you. I have strong personal commitments at the moment
that leave me unable to commit to anyone, especially a man in a romantic
way. Please understand. It may have been special and beautiful, but it
has to be over. One day I may be in a position to explain further, but
currently I cannot. I apologise once more and wish you well in your
life.”

“Maybe,” Lee looked back, “it was just a game for her.” And, no dummy,
he had learned from such experiences. Nowadays Lee was wary of anonymous
addresses with low numbers that suggested their owners had been cruising
alt.personal for a long time.

He had also learned of the usefulness of friendship as a prelude to
love. “Of all those ladies who answered my original personal,” he said,
“only one is still corresponding as a friend.” Another female friend was
also in his life online, somebody he met in an unrelated newsgroup. She
typed out an popular opinion and he wrote in to agree, and they found
they shared interests. But neither saw romance immediately ahead. Nor
was that true of the other friendships he had online. Although vague
about them, he suggested that he was still on the periphery.

Reached some months later, Lee told me he had gone on to befriend “quite
a few nice women around this campus.” In person and on the Net, however,
he had yet to meet just the right one for those river walks, museum
tours, and “giving and receiving pleasure.”

“Well, sorry, David,” Lee said, “but I didn’t have a happy ending. I‘m
sure there are some people who actually find their true loves this way.
Although I didn’t find true love, I’ve found many sincere friendships
via the Net. So I’m glad that the Net has worked for me.” I was, too,
and I wished him all kinds of wonderful surprises ahead. Chivalrous
SMHGs like Lee Chen should be more than peripherals.

Net Adultery

Places like New York or Tokyo abound with museums, art galleries, movie
houses, universities, and large pools of single people who hope to meet
the same. Something else, however, awaits those looking for it—more
opportunities for adultery than in small towns. And it is the same with
the Internet. It isn’t just that straying wives and husbands can use
those identity-stripping computers in Finland to make swap shopping
easier. More importantly, the Internet teems with bright, funny, people
who hate convention, including, in some cases, marriage.

For a stretch, a support-style mailing list came across as a Peyton
Place in cyberspace. A man and a woman met there. He told her he would
be leaving his wife and children. She spent that weekend with a _third_
member of the list; after the original man publicly confessed, she
popped up out of the blue to give her side. If anyone doubted that
computers could bring people together in person, this was proof positive
in the worst way. Most members of the list were horrified. They pleaded
for Peyton Placers to go offline. Clearly the Internet does not turn
people into saints—it just makes it easier to do what comes naturally,
good or bad.

But some context, please. The same Net could bring together
old-fashioned romantics. As shown by the Smith-Olson pairing, the Net
could actually _strengthen_ traditional values among those who so
inclined.

Besides, much of the illicit action on the Net was by the mutual consent
of husbands and wives. When I ventured into a seamy area called
alt.personals.poly, I saw an ad posted by a swinging couple from
Florida. “I am 6′3″ brown haired, considered attractive,” said Hank*,
the husband. “She is 5ʹ0″ busty, blonde, blue eyes, very pretty. We’re
not weird or disturbed or wanting to beat people, hahaha. We are very
sensual, passionate, and are good at ya know the fun stuff.” Was this
the ’Bahn that Bill and Al had in mind for us? Not quite. But it wasn’t
as if some pervert was cheating on his wife and hiding behind an
anonymous server while lusting for a nineteen-year-old coed who was new
to both life and the Net. Although I did not condone Hank’s swinging, I
actually felt a little sorry for him after he wrote me a short but
touching letter: He told how a woman had stood him up and the Missus.
Better luck next time, Hank.

Suppose, however, that a man and woman had been married for fifteen
years and had two children, he was a straight-arrow programmer type, she
was funny and sexy, he introduced her to the Internet, and she got
crushes on men whom she befriended over the wire—a marriage just might
fall apart because a stranger might actually fly in from out of town
wanting to get to know her in a biblical way. Such was the case of Phil*
and Jayne*. While I have scrambled the details of the story, it is
entirely true in spirit. They lived in Cincinnati, and Bill worked as a
programmer and an Internet administrator for his employer. He had
arranged for his wife to be able to dial up the office computer from
home and send and receive e-mail. That, as we’ll learn in a moment, was
a key fact.

In many ways Phil and Jayne were a contrast. He could “readily repair my
hurt emotions when it comes to betrayal, be it from friends, or from my
wife.” Phil held himself to the highest of standards no matter how
low-minded the rest of the cosmos was. Jayne, on the other hand, was
wild and loved to party and speak up. “She can drink anyone under the
table,” Phil said. “She has a loud voice and a happy disposition. She
can talk to anyone and make them feel at ease. She is a joy to be with.
A blonde with striking blue eyes. She has the attitude of a redhead but
we never fight. She rarely sports a smile, but when she does, it is
radiant. She has an excellent body, but she keeps on thinking it is not
quite desirable. She has gone in for plastic surgery because of her low
self-esteem.”

For some years in her life, Jayne suffered from another
problem—stodginess, of all things. Taxiing children around, nagging them
to do their schoolwork, playing the good mother, had made her too
conservative. Phil wanted the old sparks back. So he introduced her to
“an e-mail friend of mine who had been a catalyst for many parties as
well. I hoped this would spur her into action.” It did. She began a love
affair over the Net. “I often ran to the computer room after getting
home from work to find Jayne engrossed in some letter writing. She would
immediately cover the screen and ask me to leave. I could see the
discomfort in her face. This was one of my clues to ask around and to
check up on what might be happening. I caught them in the act in a swank
hotel.” For the sake of the children, however, Phil forgave her and did
not divorce. He even revived his friendship with his e-mail friend.

A second man, however, cuckolded Phil a few years later, and like the
first, he was an alcoholic. “He would hound her,” Phil said, “and send
copious amounts of e-mail, call her from wherever he was regardless of
how distant. He had an attitude that ‘no one can tell him what to do,
even if it is an affair.’” So Phil, despite his forgiving nature, did
what many red-blooded men would have done in his place as a local
Internet administrator. He deleted their electronic mail from the office
system. “The second affair rekindled after the lover’s wife left him,”
Phil says. Lawyers successfully pried Jayne and the man apart.

“She has ‘fallen’ into love with other people on the Net,” Phil said,
however, “and some have even taken the trouble to fly in to meet her.”
Fortunately the moon and the stars and the hormones weren’t right. So
where on the Net did Jayne hook up with these winners? Alt.sex.wanted?
No, Phil said—rec.humor. And he actually feared rec.humor more than he
did the plain, sex-oriented areas of the Net, because it might pave the
way for a relationship based on more than carnal impulses.

I asked, “As a local Net administrator, do you think that people on the
Net play around more or less than does the general population?”

“About the same,” Phil said. “But there are a lot more insecure
personalities acting out an alternate personality on the net. This will
often lead, I think, to more misunderstandings. Someone can appear to
love you a lot, over e-mail, but cannot carry through in person.” And
then Phil came up with another fascinating insight, which could also
apply to some relationships on the Internet between single people. He
observed that certain Netfolks really didn’t care that much about the
men or women at the other end. Rather they used electronic mail as a
diary. “Jayne cherished the e-mail she got from one of her lovers,” Phil
said, “but in person he is a lying, cheating, and abusive drunk with a
far more shallow agenda.”

Phil and Jayne were doing what they could to repair the damage. The two
had undergone marriage counseling. “Stop trying to think so much,” Phil
was told. “This makes you appear to be walking on eggshells, making it
harder for Jayne to be honest with you.” I hoped the counseling would
work. As if her infidelity weren’t enough, she now cried because she
might have contracted the virus that causes AIDS. “One of her lovers has
slept around a lot and shot up drugs,” Phil said. “He hasn’t seen a
doctor in ages because of his alcoholic tendencies, and on one occasion
he has said he could have the HIV virus. I assured Jayne ... we will
handle any result from the test one day at a time.” The same thought
might apply to his life with Jayne. One day at a time. In the future, I
hoped, she won’t be so secretive about the dots on her computer screen.

Greg and Sue, an Update

I promised to update you on Greg and Sue. In late May 1995 Greg told me
they were still moving ahead, except that they’d decided it would be
much easier for her if they lived in the States. He would arrive at the
Kansas City airport on Wednesday, July 12, at 11:11 P.M. on American
Airlines. “My parents know,” he said. “On the surface they’re bitchy
about it—well, Mum is—but underneath they’re cool with it. Especially my
dad. He wants to come too.” The older Smith had taken his family to
Colorado years earlier during a teacher-exchange program.

“Work?” Greg went on. “Heck, I can do a lot of things. My preference
would be systems administrator or network maintenance or even Internet
guru-trainer.”

Jokes about Adelaide’s sleepiness notwithstanding, Greg would miss life
down under. He cherished “the laid-back nature of Australia. I spend a
lot of time talking to people, and in 99 of 100 cases, the shopkeeper
will take time out to have a chat about something going on in the world.
People are so open and friendly, gosh darnit. I mean friendly, not
lazy.” He would hate to give up, too, the summer days at the sea, the
music festivals of Adelaide, and the programs of the Australian
Broadcasting Commission (“it’s government funded and turns up some
really cool and alternative stuff”). He would also miss Australian Rules
Football. “Mostly that’s an art form,” Greg said. “Unlike NFL, every
player has to be able to do every other player’s job. There’s no offense
or defense, and it’s such a quick game that offense can turn into
defense in the blink of an eye.”

E-mailing me on a rainy, thundery day—from “America’s Heartland soon to
be changed to America’s Flood Plain”—Sue wrote: “Thoughts and hopes?
Well, I think the one thing I’ve had to struggle with lately is facing
up to the fear that we won’t get along. I know there’s a chance. I’ve
pretty much come to grips with it, so I think that’s a good sign. I
think we’ll work it out. I _hope_ we will, but that’s yet to be
foretold—I’m just looking forward to finally meeting my best friend.

“Where we’ll live is a little uncertain. I’m still making the rounds of
apartment complexes, trying to pick one that I like, that I think he’ll
like, and that is central to work and school.

“Telling people about Greg and me is a little tricky. Most of the people
I work with understand the basic concept of the Internet, but don’t
really understand the idea of love at first talk session. I’ve pretty
much just told people I met Greg through friends. It just makes things a
lot easier, seeing as how I don’t have to explain things over and over
again. Maybe it’s a cop-out, but everyone knows how committed I am to
Greg regardless of how we met, and that’s the important thing.

“My father remains in the dark,” she said. “My mom and I had a big
discussion about things and she felt that was the best way to handle
things with him. I’m just taking things one step at a time and dealing
with them as they come. I don’t want to throw it all in his face. He’s
still my daddy and has the best interest of his baby girl at heart.”
Earlier I’d told Sue that the hassles would vanish when she met Greg,
and she had agreed. “’Cept maybe the fact Greg will be the tallest one
at family reunions *grin*. We’ll all be arguing over whose side of the
volleyball net he’s on. Mine of course. :-) *grin*.”

Sue brought me up to date on work and school. Recently she’d switched
jobs and was now a file clerk for an appliance company where the pay was
higher and the boss friendlier. “I can pretty much study during the slow
periods, which helps a great deal, *brandishes her grade card*. Got it
in the mail today—all A’s. I’m framing this sucker—I actually pulled an
A in algebra!”

Her net.lover was getting a cc of the note to me. “Oh, Greg,” she
couldn’t resist adding, “I did some rearranging for you today. I think
you might be able to have a drawer or two in the dresser *grin* just
kidding. I cleaned my room today and vacated one-half of my drawer
space, a major accomplishment almost tantamount to the A in algebra.
Just don’t look in the closet.”

Redirecting the note back to me, Sue said: “I’ve always been up front
with Greg about who I am and how I look and how I act and all that
stuff. There’s going to be a lot of rough edges we’ll need to smooth
out, but I’d say we’ve got a strong foundation to build on.” Concluding,
Sue said she had undergone a round of antibiotic-hormonal treatments for
an ulcer and gained weight. “The bad news is the weight gain that went
along with it. Least now I have the bust to fill out my bathing suit.”

A few days later I heard from Greg. Uh-oh. “To put it bluntly,” he
wrote, “I am not a happy camper.” I hoped I hadn’t offended him. He and
Sue had given so much of themselves by sharing their letters with me. As
I read on, I found out the true reason for his dismay. It wasn’t an
ever-curious writer, or parents, or friends, or professional colleagues:
Greg had graduated from school and was doing fine with temporary
consulting work. “Visa—problem, big problem. My visitor’s visa has been
denied on the grounds that I have insufficient reason to return to
Australia. The upshot of this is that our wedding and my travel plans
have been severely disrupted, delaying us by anything upwards of about
two months—gawd, I hate the sound of that. I talked to Sue on the phone
last night-her morning, and we’re confident we can make it through
this.”

In character Greg was using the Net, and specifically the newsgroup
alt.visa.us, to help him cope with the visa’crats.

“It makes no sense to me that the U.S. government won’t let in someone
with a college degree that’s in demand in this country,” Sue wrote, “and
who speaks English with such a sexy accent.”

She had one last update later in June: “There’s one thing you _have_ to
change in your chapter, and it’s just one line. I went to the oncologist
and he said I’d had enough tissue regeneration that was healthy to give
me some hope of being able to have kids. So I guess I just might get to
explore the world of labor pains and stretch marks after all. _Ugh._

“And I know this sounds cheezy, but would you mind altering names?”

I was happy to oblige.

“The press here in Kansas City,” Sue said, “has an absolute field day
with stuff like this. A guy got a mail-order bride from Russia a year or
so ago, and they had a five-part segment on his life story in the paper
and on the news. I’d just rather not be looked at as someone who had to
go to a whole other country to find a date. Which is how my father puts
it *sigh*.”

Oh, she had finally told. I wished I could see her father’s face when
Greg actually materialized in K.C. In the most direct way Fred Olson*
might understand how fortuitously the Net had enlarged his daughter’s
range of choices. What counted wasn’t her finding a man, but the best
man for her—whether he was next-door or an ocean away.

                  *       *       *       *       *

So that was how matters stood with Sue and Greg as the presses were
about to turn. I pondered the visa problem. Damn the feds. Already the
ayatollahs of the Senate had been trying to turn the Internet into _Mr.
Roger’s Neighborhood_, while the crew in the White House was crusading
to make the Net more snoop-friendly. Now Washington was getting in the
way of both a romance and a more definitive ending to my love chapter.

As I typed those words I was listening to a RealAudio replay of Senator
James Exon pushing his censorship bill on the Senate floor—an outrage
that could harm not only net.sex but net.love, given the major danger of
abusive enforcement. I loathed the man’s voice. The bullying
selfrighteousness struck me most of all. Exon’s tone was too close to
that of the late Senator Joseph McCarthy, the anti-communist zealot from
Wisconsin. In a very narrow way I regretted that the Cold War was over.
Now the bigots and bullies could focus on _domestic_ troublemakers.
Listening to the digitized Exon, I heard him say that a Nebraskan
football coach had cheered him on. I reflected. Perhaps the senator and
the coach could do a RealAudio broadcast from the locker rooms and show
that in their territory even the after-game talk was G-rated.

My thoughts drifted. RealAudio reminded me of another recent wrinkle,
The Internet Phone, which let Netfolks talk all over the world for free
if they paid flat rates for Net service. What a joy this might be for
people like Greg and Sue in the days before they rushed into each
other’s arms at the airport.

There were a few catches. You needed a deluxe Net connection, alas,
which Sue lacked.

So she and Greg would still have to reach out and touch type to each
other.

That wasn’t so bad, actually. They were saving their e-mail, and someday
the files would remind them of all the promise, all the anticipation,
that the Net had held out for them in the form of each other.

Although I tinkered with The Internet Phone, I preferred electronic
mail, just as I’d normally favored international Morse code over voice
during my amateur radio days. Now that art might be lost. Code didn’t
matter as much on the airwaves as before. The U.S. Coast Guard was
phasing it out. Any future SOS would apparently be in bits and bytes
rather than in dots and dashes, assuming the initials remained at all.
What would also perish—writing on screens, eventually? Just what would
happen to typed words on the Net?

Whether seriously or just as a discussion provoker, a Seattle columnist
had imagined the following: “It’s the year 2020; your daughter Emily is
nine years old and she can’t read or write. Is this your worst nightmare
about our schools come true? Nope, Emily just doesn’t need to read or
write anymore.” That, of course, was exactly the kind of nightmare I’d
had on my mind in proposing TeleRead. We needed graphics, not just
words; but surely we could do better than the Emily scenario.

I’d asked Avodah Offit for comments on net.love rather than on the
effects of the technology in general, but she couldn’t help warning
about the almost inevitable transition of the Net to sounds and images
for all.

Delighted by the renaissance of writing on networks, she’d e-mailed me:
“I think two-way TV will bring us down to earth. It will be a loss
rather than a gain to those of us who enjoy using our imaginations and
our writing skills. Right now we all have an opportunity to use the
literacy that humans have spent thousands of years developing.”

That was how I felt, too, whether the topic on the Net was romance or
gerbil care. An old pop lyric came to mind: “These are the good old
days.” I wondered about the Snubbites and how they would have felt about
Greg and Sue and the many others the Net had brought together; about the
leather-jacketed kids up in Nova Scotia who, for the first time in their
lives, were looking forward to _writing_, however rudimentary the elite
Snubbites might have considered the children’s prose; about all the love
letters that might go unwritten if TV-centric politicians let Emily and
friends live out their lives as illiterates without electronic books or
keyboards or equivalents.

Some things were forever worth our being reactionaries in an enlightened
way. Literacy was one of them. We mustn’t ever let the romance and
civility of the written word die on the Internet.

Once again I recalled some e-mail Sue had sent, in which she had not
meant to be profound but was. Sue the cancer survivor had reminded us of
the need to enjoy both Life and Net, and I wanted similar thoughts to
grace the screens of many lovers, in many countries, and for many years.
“*hugs greg* hold your horses sweetie,” she had written, “I’m typing as
fast as I can....”




                                 Notes

Chapter 1—The Terrain

Footnote 1.1:

  The three Net-hostile quotes are from Joshua Quittner’s “Back to the
  real world: New books from the front lines of the information
  revolution urge cyberspace cadets to get a life,” _Time_, April 17,
  1995, page 56.

Footnote 1.2:

  Luddites, of course, were the loom smashers of the nineteenth century
  who protested automation.

Footnote 1.3:

  Goldberg is author of the book _Questions and Answers about
  Depression_ (Charles Press, 1993), but the book is clearly _not_ his
  main reason for being on Walkers—mentions of _Questions_ have been
  well within limits. Sheer altruism is clearly his true motive.

Footnote 1.4:

  Reid Kanaley, “Computers to the rescue: Internet becoming a worldwide
  safety net,” _Philadelphia Inquirer_, January 17, 1995, page 1.

Footnote 1.5:

  Kanaley.

Footnote 1.6:

  John Schwartz, “On the information net, creativity is its own reward,”
  _Washington Post_, April 10, 1995, page 23 of the “Washington
  Business” section. Schwartz is a _Post_ reporter and columnist.

Footnote 1.7:

  Quittner.

Footnote 1.8:

  Stoll himself noted the Maine-Texas allusion.

Footnote 1.9:

  Irwin Lebow, _Information Highway & Byways: From the Telegraph to the
  21st Century_ (Piscataway, New York: IEEE Press: 1995), page 17. A
  good book. Highly recommended. It even comes with the _Walden_
  allusion, although from a rather different perspective from that of
  Stoll.

Footnote 1.10:

  Thanks to my friend Andy Oram for the buffalo analogy.

Footnote 1.11:

  With hypertext links, readers could click on mentions of the _Star
  Tribune_ and immediately go from my area of the World Wide Web to the
  one where the newspaper had posted the West article. I didn’t
  reproduce the material; I just pointed my readers in its direction.

Chapter 2—Business on the Net:
From White Rabbit Toys to “Intel Inside”

Footnote 2.1:

  The physical description is based on photographs in local newspapers.

Footnote 2.2:

  _Advertising Age_, January 9, 1995, page 22 of the “Interactive Media
  & Marketing” section.

Footnote 2.3:

  Peter Lewis, “Prodigy is leading its peers onto the World Wide Web,”
  _New York Times_, January 18, 1995, page D1.

Footnote 2.4:

  _Interactive Publishing Alert_ is available for $195 for 12
  monthly issues via e-mail, and $245 by regular mail. Contact
  71333.1473@compuserve.com or rosalind@harrison.win.net for more
  information, or write Rosalind Resnick at 1124 Harrison St.,
  Hollywood, FL 33019.

Footnote 2.5:

  _The Cook Report_, written for the Net savvy and dealing heavily with
  local and state Net issues, costs $85 for individuals and $350-$650
  for corporations. Cook’s e-mail address is cook@cookreport.com; his
  physical address, 431 Greenway Avenue, Ewing, NJ 08618.

Footnote 2.6:

  Rates for new customers increased after the _Times_ article on Larry
  Grant appeared in mid-1994.

Footnote 2.7:

  Mark Lyon, “Firm gives air freight a lift on Internet,” _Air Commerce
  Special_ supplement, page 8, distributed with the _Journal of
  Commerce_, December 19, 1994.

Footnote 2.8:

  Of course, on occasion, electronic mail can be delayed for several
  hours and maybe even longer. So Telnet or the World Wide Web would
  probably be better in situations where couriers are on tight
  schedules.

Chapter 3—EntertaiNet: A Few Musings on Net.Rock,
Leonardo da Vinci and Bill Gates, Bianca’s Smut Shack,
and David Letterman in Cyberspace

Footnote 3.1:

  ISDN means Integrated Services Digital Network, which allows
  transmissions faster than the 14.4 Kbps and 28.8 Kbps rates so common
  today.

Footnote 3.2:

  Barry Walters, “The Internet is a punk rocker now,” _San Francisco
  Examiner_, February 27, 1974, page D3 (Style section).

Footnote 3.3:

  Laurel Taylor, “The speed of sound,” _Good Times_, August 18, 1994.

Chapter 4—Pulped Wood versus Electrons:
Can the Print World Learn to Love the Net?

Footnote 4.1:

  A.C.’s work is on the Net, but in the strictest sense he himself
  isn’t. His daughter at a paper in Florida can enjoy his columns online
  but can’t even swap e-mail with him. Perhaps she’ll eventually conquer
  his technophobia. A.C., I’m rooting for you.

Footnote 4.2:

  Frank Daniels III, “One newspaper’s journey on the Internet,” _T
  Leaves: A Newsletter for NAA Members_, October 1994. NAA is the
  Newspaper Association of America.

Footnote 4.3:

  David Streitfeld, “Book report,” _Washington Post_, September 25,
  1994, page 19 of Book World section.

Footnote 4.4:

  Lewis and many other journalists here do not necessarily serve as
  official spokespeople for their publications.

Footnote 4.5:

  Teresea Martin, “Like a newspaper, but better: Tablets will succeed
  where others have failed,” _Digital Media: A Seybold Report_,
  September 13, 1994.

Footnote 4.6:

  Jonathan Seybold, “How the rise of electronic media is affecting paper
  prices,” _Digital Media Perspective_, March 27, 1995.

Footnote 4.7:

  To Baker’s credit, he seems to have learned about the new media since
  writing the article. Commendably he came out for an online
  royalty-collection approach that would be less onerous to readers than
  the approach favored by the Clinton Administration.

Footnote 4.8:

  As usual, for aesthetic reasons, I’m using italics to show emphasis in
  place of the original capitalization.

Footnote 4.9:

  Not to be confused with the former speech writer for Ronald Reagan.

Footnote 4.10:

  I’m not beating up on the late professor, one of the best teachers I
  ever had. In his place, I’d have given the same advice. The
  limitations of 1960s technology made it difficult to think otherwise.

Footnote 4.11:

  E-mail from Bruce Siceloff.

Footnote 4.12:

  Katherine Fulton, “Heirs to newspaper make unlikely pioneers. So why
  is Frank Daniels III out on the frontier?”, _Poynter Special Report:
  Converging Technologies_, 1994, pages 5-7.

Footnote 4.13:

  Ibid.

Footnote 4.14:

  Daniels, in _T Leaves_.

Footnote 4.15:

  The speculation about _Time_’s role in the cable trade is my own. Jim
  Kinsella, one of the organizers of Pathfinder, told me that he liked
  this approach but was not necessarily speaking for the company.

Footnote 4.16:

  In Raleigh, a locally oriented arm of Time Warner might enjoy a big
  advantage over the _N & O_ someday if the newspaper lacked access to
  cable for Internet purposes. Cable will probably be much better than
  phone connections, the kind the _N & O_ uses. The best cure, of
  course, would be laws that (1) assured the _N & O_ a place on local
  cable and (2) also let the phone companies there go into the cable
  business. Then the _N & O_ could choose between Time Warner and its
  phone company allies of the present. Perhaps such laws will be on the
  books by the time you’re reading this. Meanwhile, I’ll hardly blame
  the people at Time Warner for unofficially talking up cable for the
  Internet; as noted before, I’d do the same, given the technical
  benefits.

Footnote 4.17:

  Conspiracy theorists may take note that another arm of the Newhouse
  interests, Ballantine Books, is distributing _NetWorld!_ for Prima
  Publishing.

Footnote 4.18:

  Laurie Flynn, “Getting on-line—the Microsoft way,” _New York Times_,
  November 20, 1994, page F10.

Footnote 4.19:

  The Stahlman and Smith quotes are from “Time Inc. raises its
  multimedia profile with an Internet test,” by Deirdre Carmody, _New
  York Times_, October 24, 1994, page D10.

Footnote 4.20:

  Laura Fillmore, “Online publishing: Threat or menace,” speech to the
  Online Publishing Conference, Graphic Communications Association,
  March 1993.

Footnote 4.21:

  Ibid.

Footnote 4.22:

  Ibid.

Footnote 4.23:

  Fillmore, “Slaves of a new machine: Exploring the for-free/for-pay
  conundrum,” Fifth Conference on Organizational Computing,
  Coordination, and Collaboration: “Making Money on the Internet,”
  Austin, Texas, May 10, 1994.

Footnote 4.24:

  Ibid.

Footnote 4.25:

  Vannevar Bush, “As we may think,” _The Atlantic Monthly_, July 1945.

Footnote 4.26:

  Interview with Fillmore.

Footnote 4.27:

  Fillmore, “Slaves.”

Footnote 4.28:

  Ibid.

Footnote 4.29:

  Ibid.

Footnote 4.30:

  Ibid.

Footnote 4.31:

  Rory J. O’Connor, “News firms plan on-line network,” _San Jose Mercury
  News_, April 20,1995, page 1F.

Footnote 4.32:

  Reuter Information Service, “Newspaper executives see online services
  as prime competitor,” carried by _The NandO Times_, June 9, 1995.

Footnote 4.33:

  David Streitfeld, “Cyberstrokes: For authors, e-mail offers some novel
  reader feedback,” _Washington Post_, June 9,1995, page B1.

Chapter 5—Wired Knowledge:
When They Let a Murderer Loose on the Internet

Footnote 5.1:

  Ronnie Crocker, “Executed killer lives as computer image,” _Houston
  Chronicle_, December 18, 1994, page A1.

Footnote 5.2:

  To be technical, these weren’t true physical slices, just images taken
  of the remaining surface as researchers ground down Jernigan.

Footnote 5.3:

  From an essay that Chris Gazunis wrote in a 1994 contest sponsored by
  the National Center for Education Statistics, the NASA K-12 Internet
  Project, and the National Science Foundation.

Footnote 5.4:

  Randy Hammer was another contestant in the competition that Chris
  Gazunis entered.

Footnote 5.5:

  Peter West, “Wired for the future,” _Education Week_, January 11,
  1995. The senior analyst quoted was Kathleen Fulton.

Footnote 5.6:

  The University of Colorado got a great package deal. While I couldn’t
  rate Helen according to her medical knowledge, she appeared to know
  her computer imaging cold.

Footnote 5.7:

  Not to confuse detachment with callousness. In Pelster’s place—working
  with the cadaver day after day, not just writing about him—I’d have
  coped the same way.

Footnote 5.8:

  The Associated Press quoted Oxford and Nelson.

Chapter 6—Governments and the Net:
Making Sure Orwell Was Wrong

Footnote 6.1:

  Encryption is the scrambling of messages into codes.

Footnote 6.2:

  Simson Garfinkel, _Wired_, March 1995, page 44.

Footnote 6.3:

  To simplify a bit, cryptography is the study, or the technique, of
  making secret messages.

Footnote 6.4:

  Peter Huber, _Orwell’s Revenge: The 1984 Palimpsest_ (New York: The
  Free Press, 1994).

Footnote 6.5:

  Sandy Sandford, “The intelligent island?” _Wired_, September/October
  1993.

Footnote 6.6:

  Rosalind Resnick, “Cyberbiz” column of July 3, 1995, published in the
  _Miami Herald_, on the Knight-Ridder wire and her Web site,
  http://www.netcreations.com. One of the best sites on the whole Net.
  Drop by!

Footnote 6.7:

  Exon has announced plans not to run again—his term ends in 1997. But
  who knows what can happen in the meantime?

Footnote 6.8:

  My favorite observation on the passion for censorship comes from Phil
  Kirby, a former editorial writer for the _Los Angeles Times_, by way
  of Nat Hentoff, in the book _Free Speech for Me, But Not for Thee_.
  “Censorship,” Kirby said, “is the strongest drive in human nature; sex
  is a weak second.” Thanks to Rob Chatelle of the National Writers
  Union for bringing this gem to my attention.

Footnote 6.9:

  The example of messages violating local standards comes from a
  syndicated column by Lawrence Magid that appeared in the _Washington
  Post_ on March 13, 1995.

Footnote 6.10:

  Buckley and George Will are the most famous conservative journalists
  in the United States. Among other accomplishments, Buckley is founder
  of the _National Review_. His comments appeared in an “On the Right”
  column released through the United Press Syndicate on February 24,
  1995.

Footnote 6.11:

  Perhaps the idea will have been changed by now to allow more freedom
  to librarians and the public.

Footnote 6.12:

  David Buerger, “Our lives are quickly becoming an open book,”
  _Communications Week_, May 9, 1994, page 52.

Footnote 6.13:

  Simson Garfinkel, _PGP: Pretty Good Privacy_ (Sebastopol, California:
  O’Reilly & Associates, 1995), page 88.

Footnote 6.14:

  Ibid.

Footnote 6.15:

  Ibid.

Footnote 6.16:

  William M. Bulkeley, “Cipher probe: Popularity overseas of encryption
  code has the U.S. worried; Grand jury ponders if creator ‘exported the
  program through the Internet’; ‘Genie is out of the bottle,’” The
  _Wall Street Journal_, April 28, 1994, page A1.

Footnote 6.17:

  “Tidbits on the PGP/Zimmermann case—Protecting Americans’ privacy,” an
  item that Jim Warren released in the March 6, 1995, issue of his
  online newsletter, _Government Access_.

Footnote 6.18:

  Steven Levy, “Crypto rebel,” _Wired_, February 1993.

Footnote 6.19:

  Ibid.

Footnote 6.20:

  Garfinkel, _PGP_, page 112.

Footnote 6.21:

  Ibid.

Footnote 6.22:

  Ibid.

Footnote 6.23:

  As of this writing, it looked as if Warren wouldn’t testify—perhaps
  because his remarks would have been so helpful to Zimmermann’s side.

Footnote 6.24:

  To its credit, the White House at least called attention to the First
  Amendment nightmares of the Exon “decency” bill. Given how bad the
  bill was, however, that was a little like denouncing slavery.

Footnote 6.25:

  If the case is still on, contact Hugh Miller at hmiller@luc.edu for
  information on making donations.

Footnote 6.26:

  “Another chop at the Clipper chip,” _Business Week_, February 13,
  1995.

Footnote 6.27:

  “I oppose the Clipper Chip and all forms of key escrow because it’s
  impossible to use bad legislation as a substitute for bad
  engineering,” Bob Steele told me. Yes, he’s the same CIA alum as in
  chapter 4, the one with whom I agreed in a friendly way to disagree.
  Hi, Bob—you’re right on about Clipper!

Footnote 6.28:

  Peter Lewis, “Attention shoppers: Internet is open,” the _New York
  Times_, August 12, 1994, page D1.

Footnote 6.29:

  Bulkeley.

Footnote 6.30:

  Ibid.

Footnote 6.31:

  Ibid.

Footnote 6.32:

  Privacy International is an international human rights organization
  founded in 1987 to oppose privacy invasions worldwide. It led the
  campaign to fight a national card proposal in Australia that ended up
  causing Parliament to dissolve in 1987.

Footnote 6.33:

  _Ottawa Citizen_, January 31, 1994, as reproduced by David Banisar in
  his “Bug Off!” paper for Privacy International.

Footnote 6.34:

  Bulkeley.

Footnote 6.35:

  Elizabeth Corcoran, “Bit by bit, an online collection of the Library
  of Congress to digitize artifacts,” the _Washington Post_, October 10,
  1994, page A1.

Footnote 6.36:

  Junda Woo, “Big copyright curbs sought by industry,” the _Wall Street
  Journal_, December 27, 1994, page B5.

Footnote 6.37:

  Teresa Riordan, “Profile: Even in a ‘Big Tent,’ Little Insults, Little
  Compromises,” the _New York Times_, May 29, 1994. The _Times_ is the
  source of information on Lehman’s heroes. To answer the obvious
  question—yes, I asked Lehman for comment on a number of topics ranging
  from campaign donations to his use (or possibly nonuse) of the
  Internet. No reply came. I also asked him about his controversial
  $10,000 gift to a local politician, the one described in this chapter
  and in chapter note 41.

Footnote 6.38:

  Saundra Torry, “Many of Clinton’s chosen earned big bucks in private
  practice,” the _Washington Post_, October 18, 1993, page F7.

Footnote 6.39:

  Found at http://www.uspto.gov/combio.html.

Footnote 6.40:

  Riordan.

Footnote 6.41:

  Pamela McClintock, “D.C. council candidate returns questioned $10,000
  loan,” the _Washington Times_, February 19, 1991, page B4. In a
  “Notebook on Politics” column on February 21, Rene Sanchez of the
  _Washington Post_ described the loan as “apparently in violation of
  D.C. campaign finance law, which sets a $400 ceiling on individual
  campaign donations.”

Footnote 6.42:

  Riordan is the source of the “first” information.

Footnote 6.43:

  Riordan.

Footnote 6.44:

  Pamela Samuelson, “Legally speaking: The NII intellectual
  property report,” _Communications of the ACM_, December 1994. On
  the Web at http://gnn.interpath.net/gnn/meta/imedia/features/
  copyright/samuelson.html.

Footnote 6.45:

  _The Manchurian Candidate_ was the film in which the Communists
  captured a GI, brainwashed him, and groomed their man to be president
  of the United States.

Footnote 6.46:

  Marcia Berss, “West will always be three,” _Forbes_, November 21,
  1994, page 47.

Footnote 6.47:

  Ibid.

Footnote 6.48:

  Ibid.

Footnote 6.49:

  Ibid.

Footnote 6.50:

  Sharon Schmickle and Tom Hamburger, “West Publishing and the courts:
  U.S. justices took trips from West Publishing,” _Minneapolis_ _Star
  Tribune_, March 5, 1995. In of July, 1995, at least, the lead article
  showed up on the Web at http://www.startribune.com/westpub/west.htm.
  The home page for the _Star Tribune_ is http://www.startribune.com/.]

Footnote 6.51:

  I can only speculate since, like Lehman, Opperman refused to answer my
  written queries about donations and other matters.

Footnote 6.52:

  Bill Salisbury, “Minnesota ‘bit players’ enjoy the show; Democratic
  colleagues happy with their role at convention,” the _St. Paul Pioneer
  Press_, July 14, 1994, Page 1A.

Footnote 6.53:

  West’s 6,000-word letter of February 22, 1995, was available on the
  World Wide Web at the following address in July 1995:
  http://www.startribune.com/westpub/perspectives/response.htm.

Footnote 6.54:

  Jack B. Coffman and Thomas J. Collins, “Bankrolling the legislature
  part 6: Who has the clout,” the _St. Paul Pioneer Press_, April 17,
  1992, Page 1A.

Footnote 6.55:

  Margaret Engle, “Virtual money trail: The Center for Responsive
  Politics on the Internet,” _Capital Eye_, June 15, 1995, Page 2.

Footnote 6.56:

  Martin Schram, _Speaking Freely: Former Members of Congress Talk about
  Money and Politics_ (Washington, D.C: Center for Responsive Politics,
  1995), page 85.

Chapter 7—The Electronic Matchmaker

Footnote 7.1:

  The Goodin quotes appear in the paper “The Net and Netizens: The
  impact the Net has on people’s lives,” by Michael Hauben
  (hauben@columbia.edu).

Footnote 7.2:

  The America Online example is from a personal interview, the
  CompuServe one from online messages, and the Prodigy example from
  _People_ magazine.

Footnote 7.3:

  Although anonymous servers protect privacy in most cases, this could
  be happening only up to a certain point. Many on the Net take it for
  granted that national security agencies in the United States can
  monitor traffic to and from the servers and determine the identities
  of the senders.

Footnote 7.4:

  I won’t even bother here with the term “Cyberpunk,” which nowadays can
  mean anyone from a rebellious hacker to a technophobic teenager who is
  trying to make a fashion statement.

Footnote 7.5:

  Sue tells me her hair is shorter these days, “a little past my chin
  now.” I doubt the change will imperil Greg’s ardor.

Footnote 7.6:

  A program for sending and receiving electronic mail over a network.

Footnote 7.7:

  I look forward to an era of electronic books where librarians can
  function more as book reviewers and information hunters, and less as
  clerks.




                                 Index


                                   A

 Ackerman, Michael, 103, 181, 188, 190, 192
 ACT UP, 255
 Adleman, Len, 226-227
 Adultery on Internet, 316-323
 Agnew, Spiro, 286
 AIDS
   HIV Positive Dating Services, 293
   PGP and activists, 255
 Air freight business, 68
 Alicia Patterson Foundation, 235
 American Memory Project, 126
 Americans Communicating Electronically, 263
 American Society for Information Science, 267
 America Online, 31, 32, 123, 128
   Elmer-DeWitt’s message on, 148
   _Time_ magazine on, 148-149
   WAIS Inc., 169
 Amnesty International, 211-212
 Andreessen, Marc, 44
 Anonymous servers, 221
   gamesplayers using, 299
 Antitrust actions, 168-169
 Apple Computer
   Internet gadgets, 31
   Scully, John on NII Advisory Council, 277
 Art on Internet, 83-84
 Aryan Nation, 242
 Asahara, Shoko, 261
 ASCII e-books, 163
 Ash, Danielle, 83
 At-risk students, 198-202
 AT&T, 54
   encryption chip, 240
 Attention deficit disorder, 161
 Austin Code Works, 232
 Australia, 293-294

                                   B

 Baker, Nicholson, 112-113, 170
 Baker, Stewart A., 241-242, 246-247
 Ball, Patrick, 259
 Banisar, David, 257
 Barcroft School page, 17
 Barlow, John Perry, 240-241
 Barnhart, Aaron, 88-89
 Barry, Dave, 123
 _Being Digital_ (Negroponte), 114
 Berners-Lee, Tim, 155
 Besser, Jim, 19, 122
 Bianca’s Smut Shack, 63, 84-85, 220
 Biden, Joseph, 228-229
 Bidzos, Jim, 227, 228, 230, 232, 249-250
 Big Sky Telegraph, 176
 Bitnet, 2
 Bix, 2
 Black Entertainment Television, 277
 _Bless This Food: Amazing Grace in Praise of Food_ (Butash), 159
 BMP files, 214
 Bookport, 170-171
 Book publishers, 110
 Books online, 151-165
 Bookstore, online, 121
 Bracey, Bonnie, 284
 Branch Mall, 50
   customers of, 52
 Brandy’s Babes, 29-30, 299
 Brennan, William, 279
 Brookman, Scott, 101-103
 Brown, Ron, 272
 Buckley, William F., Jr., 222-223, 247
 “Bug Off” (Banisar), 257
 Bush, George, 231
 Bush, Vannevar, 155
 Businesses
   Federal Express, 34-35
   hazards for, 76-79
   Intel, 73-76
   MCI, 34
   and Pretty Good Privacy (PGP), 255-256
   3-D style, 42-43
   White Rabbit Toys, 27-29, 35-48
 Butash, Adrian, 159
 Butler, Robert, 181, 191, 192
 Butzer, Tim, 185

                                   C

 Cable modems, 143
 Cable News Network, 123
 Canada
   government intervention, 220-221
   Park View Education Centre, 195-207
 Canadian Broadcasting Corporation, 87
 Canter, Laurence A., 23-24, 54, 116
 Caras, Sylvia, 12
 Carl-Mitchell, Smoot, 296
 Carnegie, Andrew, 222
 Carvin, Andy, 176
 Case, Steve, 215
 CAT images, 186, 188
 CBS, 87-88
   on NII Advisory Council, 277, 278
 CD-ROM, Visible Human Project and, 188, 190
 Censorship, 215-216
 Center for Responsive Politics, 279
 Cerf, Vint, 55
   political contributions by, 280
 Chen, Lee, 311-315
 Children. _See also_ Education,
   molestation on Internet, 214
   NandOLand for, 130
 Christie’s Internet MatchMaker, 293
 Christopher, Susan O’Hara, 17
 Civic League page, 17
 ClariNet, 122-123
 ClarkNet, 112
 Clinger, William, 287
 Clinton, Bill, 20, 211, 231, 279
 Clipper chip, 78, 116, 147-148, 234-242
   Green Paper compared, 275
   key escrow technique, 238
   PGP software and, 225
   terrorism and, 260-261
 Collins, Joe, 254-255
 CommerceNet, 72
 Compression software, 94
 CompuServe, 2, 31, 123
   Gore, Al on, 263
   Limbaugh, Rush and, 247, 295, 303
   “Umney’s Last Case” to, 158
 Computer Professionals for Social Responsibility, 229, 240-241
 Condom stores, 30
 Cook, Gordon, 49
 Cooke, John F., 279
   _The Cook Report on Internet_, 49
 Copyrights, 118-119
   digital libraries and, 264
   Lehman, Bruce and, 268-272
   United Kingdom regulations, 223-224
   victories for, 288-289
 Corning Glass, 280
 Crak Software, 255
 Crichton, Michael, 123
 Crimenet, 18
 Cronin, Mary, 32, 34
 Crystal City, Virginia, 268-269
 _The Cuckoo’s Egg_ (Stoll), 6
 Cyberia cafe, 25
 Cyberia (legally oriented mailing list), 243
 Cyberpunks, 230-232
 Cyberspace Development Company, 31-32
 _CyberWire Dispatch_ (Meeks), 9
 Cygnus Group, 39-40

                                   D

 Daniels, Frank, III, 106, 124, 125-126, 126-128, 130, 131-142, 165-167
 Daniels, Josephus, 125-126, 166
 _Dateline NBC_, 117
 Dating services, 292-293
 Dean, David, 192
 Dearth, Jeffrey, 144-145
 Delphi, 2, 123
 Depeche Mode, 91
 Depression, 4-5
 Dern, Daniel, 33
 _Der Spiegel_, 109
 _The Diane Rehme Show_, 6-7
 Diffie, Whitfield, 233-234
 DigiCash, 78
 Digital Equipment Corporation, 79
 Digital Publishing Association, 289
 _Doing Business on the Internet_ (Cronin), 32
 Dole, Bob, 216
 Doran, Jeff, 197-207
 Doubleday, 112
 Dubois, Phil, 248
 Dunleavy, Houston, 294
 Du Toit, Michael, 181

                                   E

 Echo, 6
 EcoGopher, 40
 EcoNet, 40
 Education, 172-207
   Park View Education Centre, 195-207
   writing skills on Internet, 198-202
 800 numbers for business, 48
 Electric classifieds, 292
 Electronic cafes, 25
 Electronic Frontier Foundation, 209, 218
 Electronic Frontier metaphor, 33-34
 Electronic libraries. _See_ Libraries
 Electronic Newsstand, 144-145
 Elmer-DeWitt, Philip, 147-148, 218
 _Elmer Gantry_ (Lewis), 216
 E-mail, 14, 59-60, 154
   from Australia, 293-294
   confidentiality of, 252-253
   with NandOLand, 130
   Pretty Good Privacy (PGP) for, 208-211
   religious confessions via, 224-225
   reporters interviewing with, 119
 Encryption software, 209-211, 224
   _See also_ Clipper chip; Pretty Good Privacy (PGP)
   National Security Agency and, 233-234
   subpoenas of makers, 232
 Engel, Margaret “Peggy,” 235-236
 Engst, Adam, 144
 _Entertainment Weekly_, 109, 146
 Envirolink Network, 40
 eWorld, 2
 Exon, J. James, 214, 215, 216, 217, 218, 220, 323

                                   F

 FBI, 228-229
   Usenet postings, collection of, 258
 Federal Election Commission, 281
 Federal Express, 34-35, 67-73
 Feinstein, Dianne, 9, 281
 Few, Sue, 100-101
 Fidler, Roger, 151
 FidoNet, 213-214
 File Transfer Protocol (FTP), 14
 Fillmore, Laura, 121, 151-165, 163
 Firewalls, 78
 Flaming, 118
 Foley, Tom, 282-283
 Fong, Kendrick, 258
 Forms, 267
 France, encryption rules in, 238-239
 Freedom of Information Act, 222, 286
 Freeh, Louis, 219
 Freelancing, 153
 Fry, David, 47, 54
 Fry Multimedia, 54
 FTP (File Transfer Protocol), 97
 _The Future Does Not Compute_ (Talbott), 3

                                   G

 Gamesplayers, 298-299
 Garfinkel, Simson, 227, 232
 Gatekeepers, 122
 Gates, Bill, 84
 Gazunis, Chris, 177
 General Electric
   hackers and, 78
   Web area of, 35
 General Services Administration, 286-287
 GEnie, 2, 123
 GenNet, 99
 German encryption regulations, 239
 Gilder, George, 17, 247-248
 Gilmore, John, 215
 Gingrich, Newt, 219, 247, 287
 Glaxo Inc., 181, 190
 Global markets, 120
 _Global Net Navigator_, 144
 Goen, Kelly, 229
 Goldberg, Ivan, 5
 Goodin, Laura, 294
 Gopher, 14
   for business, 41
 Gordon, Mike, 129
 Gore, Al, 156, 263, 269, 272
 Gore, Tipper, 92
 Gores, Luciana, 35-36, 47
 Government. _See also_ Clipper chip
   and encryption software, 209-211
   information on Internet, 212
   TeleRead and, 268-274
 _Government Access_, 245, 287
 Gramercy Press, 56-64
 Grant, Larry, 33-35, 38, 48-54
 Grant’s Flowers, 33-35, 48-54
 Graphics, 10
 Grassley, Charles, 215, 219
 Green, Jordan, 119
 Green Paper, 96, 273-276
   Clipper chip compared, 275
   NII Advisory Council on, 285-286
 Gribble, Paul, 144
 Grove, Andy, 74

                                   H

 Hackers, 78-79
   Clipper chip and, 240
   public PGP keys, 250
 _The Hacker’s Dictionary_, 156
 Hamilton, Robert, 71-72
 Hammer, Randy, 177
 Harmon, Dave, 7-11
 Harnad, Stevan, 174
 HarperCollins, 112
   News Corps, 170
 Harris, Eric, 136, 140, 142
 Hart, Gary, 216
 Hellman, Martin, 233-234
 Helms, Jesse, 107-108
 Helsingius, Johan, 221
 Henderson, Bill, 3
 Hertz, J. C., 3, 16
 Hesseldahl, Arik, 120
 High school use of Internet, 179
 HIV Positive Dating Services, 293
 _HotWired_, 113-114, 144, 147
 Houghton, James, 280
 _How to Make a Fortune on the Information Super-highway_ (Canter and
    Siegel), 24
 Hubbard, Stanley, 280
 Hubbard Broadcasting, 280
 Hubert, Martin, 69
 Huffman, David, 93-94
 Huffman coding, 94
 Hypertext, 161
   _Bless This Food: Amazing Grace in Praise of Food_, 159

                                   I

 Images, 10
 Information Industries Association (IIA), 269
 Information kiosks, 222-223
 _Insider_, 135
 Intel, 35, 73-76
 Intellectual piracy, 288
 “An Interactive Citizens’ Handbook,” 262-263
 _Interactive Week Publishing Alert_, 110
 Internal Revenue Service, 223
 _International Teletimes_, 144
 _Internet Companion_ (LaQuey), 155-156
 Internet Engineering Task Force, 55
 Internet Phone, 324
 Internet Relay Chat, 14
 Internet Sleuth, 217
 Internet Underground Music Archives, 13, 22, 80-81, 86-87, 90-104
   “Arbeit Macht Frei,” 96-97
   World Wide Web, discovery of, 98
 Isaacson, Walter, 148-149
 ISDN phone connections, 86
 Italy, 213-214
 IUMA. _See_ Internet Underground Music Archives

                                   J

 J. C. Penney, 141
 Japan, terrorists in, 260-261
 Jargon guide, 14
 Jernigan, Paul, 172-173, 179-185

                                   K

 Katz, Jon, 123
 Katzen, Sally, 287
 Katzenberg, Jeffrey, 279
 Kennedy, Anthony, 279
 Kerouac, Jack, 302
 Key escrow, 238
 Killen & Associates, 32
 King, Stephen, 157-158
 Kinsella, Jim, 149
 Klien, Eric, 292
 Knight-Ridder, 129, 169
 Kostmayer, Peter, 283-284
 K12Net, 176-177
 Kuster, Sharon, 194

                                   L

 Lande, Jim, 17
 LaQuey, Tracy, 155-156
 _The Late Show._ _See_ Letterman, David
 Learning Connections, 197
 Legal issues. _See also_ Copyrights
   MCI and, 62-63
   of RSA, 227
 Lehman, Bruce, 20, 96, 222, 268, 269-272.
   _See also_ Green Paper on National Information Infrastructure, 264
 Leno, Jay, 2, 82, 89
 Letterman, David, 2, 75, 82, 87-89
 Levy, Steven, 230-231, 234
 LeWebLouvre, 83-84
 Lewis, Peter, 106-107, 118-119, 217
 Lewis, Sinclair, 216
 Libraries, 112-113
   copyrights and, 264
   information kiosks, 222-223
   national digital libraries, 22, 24, 118, 121, 162-165
   TeleRead-style libraries, 162-165, 265-268
 Lilienfeld, Bob, 27-29, 35-48, 77, 141
   MCI and, 65
 Lilienfeld, Jo Ann, 27-29, 35-48, 77, 141
 Limbaugh, Rush, 247, 295, 303
 Liquor advertising, 217
 Litman, Jessica, 274
 Lobbyists, 20-21
 Local-standards principle, 219-220
 _London Telegraph_, 109
 Lord, Rob, 80, 86-87, 90-104
 Loser Records, 102, 103
 Love, James, 287
 Lowry, Stuart, 37, 47
 Luce, Henry, 146
 Luddites, 3-4, 6
 Luini, Jon, 98, 102
 Lycos
   business and, 50
   print media and, 119-120
 Lynx, 15
 Lysator, 8
 Lytel, David, 268, 289
 .ix

 .nf c
 M
 .nf-

 .ix
 McCarthy, Joseph, 323
 McClatchy Newspapers, Inc., 166
 McCracken, Ed, 277
 McGraw-Hill, 110
 McLarty, Mack, 278
 Macmillan, 13, 110
 Madness, 12
 Magazines, 142-151
   barriers to publishing, 150
 Magid, Larry, 56
 Mailing lists, 7-8, 14-15, 115
 Mammoth Records, 140-141
 Mariam, Mengistu Haile, 259
 Markey, Ed, 280
 Marriage through Internet, 301-311
 Martin, Teresa, 107
 MasterCard numbers, 77
 Match.Com, 292
 Matchmaking on Internet, 291-325
   adultery on Internet, 316-323
   Chen, Lee, story of, 311-315
   marriage through Internet, 301-311
 _Matrix News_, 296
 Max, T. J., 113-114
 May, Timothy, 230-231, 242-244
 MCA, 280
 MCI, 34, 54, 55-67
   e-mail, 59-60
   fees, 66
   Murdock, Rupert and, 169-170
   political contributions by, 280
 MCI Mail, 2, 64-65
 Meeks, Brock N., 9, 147
 Mendel, Gregor, 176
 MendelWeb, 176, 189
 Metalitz, Stephen, 269
 Microsoft
   copyrights and, 270-271
   Internet gadgets, 31
   newspaper online service, 129
   NII Advisory Committee, representation on, 277-278
 Microsoft Network, 168-169
 _The Mini Page_, 263
 Mitnick, Kevin, 238, 244
 Money, electronic, 78
 Moriarty, Michael, 82
 Morton, Father Bill, 224-225, 250-252
 Mosaic, 15, 22, 155
   _Raleigh News & Observer_ on, 132
   The Internet Adapter and, 31-32
 Moss, Kate, 90, 94
 Mozilla, Netscape, 44
 MPEG compression, 94-95
 MRI images, 186, 188
 Multi-User Dungeons, 85-86
 Murdock, Rupert, 170
 Music, 86.
   _See also_ Internet Underground Music Archives

                                   N

 Nader, Ralph, 278
 Nadler, David, 258
 NandOLand, 130
 NandO.Net, 131-135
 _NandO Times_, 165
 National Information Infrastructure, 263-264, 269.
   _See also_ NII Advisory Council
 National Institute of Technical Standards, 235
 National Security Agency, 229-230, 233-234
   authority of, 236
 Negative advertising, 79
 Negroponte, Nicholas, 114
 Neilsen, Lorri, 204, 205-206
 Nelson, Marc, 192
 Nelson, Ted, 155
 _The Net_, 2, 82
 _Netiquette_, 171
 Net Market, 256
 Netscape, 15, 22, 169
   business and, 43-44
   WebSpace with, 42
 Net surfing, 302
 New Century Network, 168
 News Corps, HarperCollins, 170
 Newsgroups, 7-8, 15
 _News & Observer._ _See_ _Raleigh News & Observer_
 Newspapers, 105-109, 121-142
 _Newsweek_, 2
 NewtWatch, 283
 _New York Times_, 108
 Nicely, Thomas, 74
 NII Advisory Council, 276-278
   on Green Paper, 285-286
   political donations by members of, 279-281
 _1984_ (Orwell), 211-212
 Nixon, Richard, 266
 Noonan, Peggy, 119-120
 Nova Scotia Technology Network, 198-199

                                   O

 O’Connor, Rory, 168
 O’Connor, Sandra Day, 279
 Offit, Avodah, 295, 300, 325
 Oklahoma City bombing, 8
 _Omni_, 110
 Online Bookstore, Rockport, Massachusetts, 151-165
 _On the Road_ (Kerouac), 302
 Opperman, Vance, 276-277, 278, 281, 282, 290
 O’Reilly, Tim, 169
 O’Reilly and Associates, 160, 169
 Orwell, George, 211-212
 _Orwell’s Revenge_, 246
 Oxford, Gerry, 192

                                   P

 Packwood, Bob, 216
   political contributions to, 280
 _Palo Alto Weekly_, 109
 Parental control, 132, 215
   Pretty Good Privacy (PGP) and, 253-254
 Parents Music Resource Center, 92
 Park View Education Centre, 195-207
 Parrella, Bernardo, 213
 Password recovery software, 255
 Patent Office Web site, 270-271
 Pathfinder site, 142, 145
   connect fee for, 149
   planning the, 147
 Patterson, Jeff, 80, 86-87, 90-104
 _PC Magazine_, 109, 114-115
 Pearl Jam, 193
 Peek, Robin, 111-112
 Peightel, Joseph, 178
 Pelster, Helen, 185, 188
 Pelster, Martha, 103, 185
 Pentium chip, 73-76
 People for the Ethical Treatment of Animals, 193
 _People_ magazine, 109
 Pettit, Mark, 57, 63, 64, 65
 _PGP: Pretty Good Privacy_ (Garfinkel), 227, 232
 Phair, Liz, 12
 Pictures, 10
 Pioch, Nicholas, 83-84
 Piracy of music, 99-100
 _Playboy_, 1
 Political activists and PGP, 257
 Pornography. _See_ Sex areas
 Postal Service, 222-223
 Powell, Lewis, 279
 Powers, Julie Ann, 136-138
 Pretty Good Privacy (PGP), 208-211, 224-262
   AIDS activists using, 255
   businesses using, 255-256
   political ideas and, 257
   religious communications, 250-252
   teenagers using, 253-254
 Privacy, 116.
   _See also_ Clipper chip;
   Security of e-mail, 252-253
   Pretty Good Privacy (PGP), 208-211
   Samaritans and, 252-253
 Prodigy, 2, 31, 124, 128-129
   matchmaking on, 295
 Project Gutenberg, 110, 152
 Prostitution, 18
   “Brandy’s Babes,” 29-30
 Public key, 226-227
 Public Key Partners, 227

                                   Q

 Quarterman, John, 154, 296
 “Quick Reads,” Time Warner, 171

                                   R

 Radio on Internet, 81
 Radio Shack, 141
 _Raleigh News & Observer_, 105-106, 120, 121-142, 165-168
   Discoveries column, 136-138
   Lawson execution story, 138-139
   NandO.Net, 132-135
   sports areas, 136
 Random House, 13, 110
 Rathje, William, 39, 40
 Ravensburger, 36
 RealAudio, 81-82, 323-324
 Resnick, Rosalind, 49, 131, 215-216
 Ribicoff, Abraham, 286
 Rice, Donna, 216-217
 Right-O-Way, 69, 72-73
 Rimm, Martin, 218-219
 Riordan, Teresa, 270
 Rivert, Ronald, 226-227, 228
 Roberts, Bert, Jr., 280
 Romance on Internet, 291-325
 Rovner, Sandy, 214
 RSA Data Security, 227, 230
 RSA encryption, 226-227
 RSCPublic Key Partners, 250
 _Rubbish! The Archaeology of Garbage_ (Rathje), 39

                                   S

 Sackman, Gleason, 35-36
 Sailor, 178
 Sais, Jim, 271
 Samaritans, 252-253
 Samuelson, Pamela, 274
 _San Jose Mercury News_, 108-109
 Scalia, Antonin, 279
 Scams on Internet, 73
 Schlukbier, George, 128-130, 130, 140, 141
 _Scholarly Publishing: The Electronic Frontier_, 22
 Schools, Park View Education Centre, 195-207
 Schwartz, John, 12-13, 117-118
 Scully, John, 277
 Security, 77.
   _See also_ Privacy Pretty Good Privacy (PGP) for, 208-211
 Selverstone, Katy, 64
 Sex areas, 17.
   _See also_ Matchmaking on Internet
   alt.sex.bestiality, 18
   government intervention in, 214
   local-standards principle, 219-220
   on NandO.Net, 132
 Seybold, Jonathan, 108
 Shamir, Adi, 226-227
 Shein, Barry, 155-156
 Siceloff, Bruce, 126
 Siegel, Martha S., 23-24, 54, 116
 Silicon Graphics, 188
 _The Silicon Jungle_, 61-62
 _Silicon Snake Oil: Second Thoughts on the Information Highway_
    (Stoll), 1, 6, 16, 106
 Singapore, 212-213
 Sitton, Claude, 126-127
 SLED, 250
 Smith, Richard M., 150
 Smokin’ Joe’s tobacco products, 217
 Snow, A. C., 105, 135
 Snubbites, 3-4, 6
   on WebMuseum, Paris, 83
 _Sound Check_, 100-101
 South Africa’s _Weekly Mail & Guardian_, 109
 Spamming, 23
 Spearman, Walter, 121-122
 Spernow, William, 259
 Spielberg, Steven, 279
 Spitzer, Victor, 185
 _Sports Illustrated_, 109
 Spyglass Enhanced Mosaic, 42
 Stacker, 94
 Stahlman, Mark, 150
 Stakeholders, 283, 290
 Stanford Netnews Filtering Service, 258
 Stanley Kaplan, 29
 Steele, Robert David, 115-117, 255, 260, 261-262
 Stevens, John Paul, 279
 “Still Suck” (Katz), 123
 Stith, Pat, 127
 Stoll, Clifford, 1, 4, 6, 7, 10, 13, 16, 19-20, 83, 106, 112, 174-175,
    282
 Suicidal persons, 10-11
 Sun Microsystems, 158
 _Sunset_ magazine, 146
 SunSite UNC, 140-141
   Internet Underground Music Archives on, 98
 Support groups, 4-12
 _Surfing the Internet_, 3
 Surfing the Net, 302
 SurfWatch, 215
 Sweden, regulation in, 245
 Swidler & Berlin, 271
 Symbols for e-mail, 119

                                   T

 Tablet-size computers, 151
 Talbott, Stephen L., 3
 Tankersley, Nancy, 17
 Taxpayer Assets Project, 277, 278
 Teachers, 174-175
 Telephone companies, 54
 TeleRead, 21, 22, 162-164, 265-274
   Green Paper and, 275-276
   NII Advisory Council on, 284-285
   profits from, 288-289
 TeleReaders, 150-151
 Telnet, 15
   into Right-O-Way, 69
 Terrorism, 260-262
 _The Terrorist’s Handbook_, 8-9
 Texas Internet Consulting, 296
 The Internet Adapter, 31-32, 76
 Thoreau, Henry David, 22
 Ticer, Mark, 183-184, 194
 Tidbits, 144
 _Time_ magazine, 2, 13, 109, 142-151
   cyberporn article, 218
 Time Warner, 13, 109, 110, 121, 142-151.
   _See also_ Pathfinder site
   “Quick Reads,” 171
 Tobacco advertising, 217
 Treasury Department, 235

                                   U

 Ugly Mugs, 80, 93
 _ULS Report_, 40-41
 “Umney’s Last Case” (King), 157-158
 United Kingdom, 223-224
   political activists in, 258-259
 UNIX commands, 297
 _U.S. News & World Report_, 146
 Usenet, 122, 127
   censorship of, 134
   FBI collecting postings, 258
   political freedom of, 133-134
   sexual areas of, 132

                                   V

 Valenti, Jack, 277
 ViaCrypt, 228, 232
 Videotext, 124
 Video transmissions, 82
 _Virtual Love_ (Offit), 295, 300
 Virtual MeetMarket, 293
 VISA numbers, 77
 Visible Human Project, 173-174, 179-195
   ideal candidate for, 182
 VLSI Technology encryption chip, 240

                                   W

 WAIS Inc., 169
 _Walden_ (Thoreau), 22
 Walkers in Darkness, 4-11
 Walt Disney, 277, 278, 279
 Warren, Jim, 18, 229, 244-245, 273, 287
 _Washington Post_, 122
   avoidance of Internet, 141
 We, Gladys, 297-298
 WebMuseum, Paris, 83
 Web Personals, 293
 WebSpace, 42-43
 The WELL, 6, 147-148
 West Publishing, 20, 25, 277-279, 286
   political contributions by, 281-282
   thwarted on Internet, 287
 White, Byron, 279
 White Rabbit Toys, 27-29, 35-48
 Whitlock, David, 185
 _Windows Magazine_, 285
 Windows 95 operating system, 31
 Winter, Peter, 168
 Winterbotham, Russ, 25
 _Wired_, 147
   Max, T. J. on, 113-114
   Singapore, article on, 212-213
   “Still Suck” (Katz), 123
 Wire tapping, 257-258
 Wirt, Richard, 74
 Wojtowicz, Ian, 144
 Wolfe, Michael, 47
 Women on Internet, 296-298
 World Wide Web, 15
 ix-
 .nf c
 X
 .nf-
 .ix
 Xerox, 107

                                   Y

 Yellow Pages, 54
 Yeltsin, Boris, 257

                                   Z

 Zappa, Frank, 92
 Zeeff, Jon, 53-54, 55
 _Zen and the Art of the Internet_, 156
 Zimmermann, Phil, 208-211, 224-230, 232, 238, 256-257, 262, 266
   government harassment of, 244-245
   legal costs for, 248-249

------------------------------------------------------------------------

                           Transcriber’s Note

Errors deemed most likely to be the printer’s have been corrected, and
are noted here. The references are to the page and line in the original.
The following issues should be noted, along with the resolutions. FedEx
is referred to three times with the space (e.g. Fed Ex). These have been
removed where it occurs to facilitate text searches.

The quotation at 143.12 (see below) is misprinted, but it is not clear
how. We’ve chosen to retain the opening quote and provide the missing
close. A similar thing happens at 310.14. The sense would dictate that
the quotation continue from ‘really cool chapel’. The added closing
quote is harmless to the sense.

On p. 259, the technical term ‘uuencoding’ is almost certainly meant for
‘unencoding’, which makes no sense in the context. We suspect an
over-zealous but not very technical editor/proofreader.

  6.34     _The Diane Rehm[e] Show_                       Removed.

  13.21    [“]Business on the Net                         Removed.

  44.16    the browser’s technical wizardry[,] was        Removed.
           winning

  45.22    it[’]s a social phenomenon.                    Inserted.

  64.19    a little boilerplate from their Dar[e]lene-bot Removed.

  69.1     same services that Fed[ ]Ex could.             Removed.

  71.8     check out Fed[ ]Ex’s service availability      Removed.

  83.36    Within Le WebLouv[r]e>—there, I’ll say it      Inserted.
           anyway

  94.5     routines of one kind or another are de         Inserted.
           rigue[u]r for

  94.6     the space that the material require[s]         Added.

  95.21    for I[MU/UM]A to give MPEG one of its biggest  Transposed.
           boosts

  96.17    because you’ll be working.[’]                  Removed.

  113.21   M[u/o]st of the time I don’t know              Replaced.

  123.24   I spent several week[s] talking                Added.

  143.12   its duties to its stockholder[s]               Added.

  149.3    “with advertising it should be in the black    Added.
           within a year.[”]

  152.35   to get special permission to use Fed[ ]Ex.     Removed.

  170.6    just as the fledg[l]ing rockers of IUMA did    Inserted.

  172.8    More than [a ]decade had passed.               Inserted.

  181.11   than on using [the ]them                       Removed.

  222.22   American[s] can educate themselves             Added.

  230.17   the Nation[al] Rifle Association               Added.

  233.34   authenticate their identi[f/t]ies from the     Replaced.
           start

  238.4    by way of moronic exp[e/o]rt controls          Replaced.

  242.23   postings to the Cyp[h]erpunks’ rather public   Inserted.
           list

  244.28   innocent citizens and law-a[b]iding businesses Inserted.

  247.8    millions of younger American[s] who surfed     Added.
           freely

  251.9    In the history of Anglican pastoral ca[s/r]e   Replaced.

  257.8    It facilit[i/at]es the flow of ideas           Replaced.

  257.27   used in Kenya, Mali, Senegal, Egypt, and       _sic_:
           [Mali]                                         Somalia?

  259.12   He confused PGP with u[n/u]encoding            Replaced.

  302.27   like the Jack Kerouacs of [the ]’50s           Added.

  310.14   for their fiftieth wedding anniversary.[”]     Added
                                                          (probable).

  315.30   [“]I‘m sure there are some people              Added.

  329.15   _Digit[i]al Media: A Seybold Report_,          Removed.

  334.1    [In of July], 1995, at least, the lead article _sic_: the
                                                          edition of?

                        Sample Chapter heading.

[Illustration]

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