that motion can be produced with the aid of the electric current in
many different ways. It can be produced at the ends of wires which
simply reach across the room, or which reach miles from the source
of the current. To get practical results for commercial purposes we
require a proper source of current, proper conductors, and proper
apparatus to convert the motions into useful work. The motions given to
the parts of the apparatus in the previous experiments are not suitable
for commercial purposes, as they are in straight lines. A rotary motion
is needed to do good work; and when this is applied to a shaft, belts
can be used to run all sorts of machinery. (See Electric Motors.)
[Illustration: Fig. 148.]
=EXPERIMENT 189. Rotary motion with a hollow coil of wire and a
permanent magnet.=
=453. Directions.= (A) Arrange as in Fig. 148. A key can be
used instead of the reverser. The coil of the galvanoscope, G
V, has a magnetic field about it when the circuit is closed.
The needle has a permanent field.
(B) Close the circuit for an instant, let the needle swing back
past the zero mark, close the circuit again, etc., until the
added impulses give the needle a complete turn.
(C) Keep the needle turning on its axis by opening and closing
the circuit at the proper time. With a little practice you can
make it turn rapidly.
(D) Reverse the motion of the needle. (See § 455.)
[Illustration: Fig. 149.]
=EXPERIMENT 190. Rotary motion with an electromagnet and a
permanent magnet.=
=454. Directions.= (A) Arrange as in Fig. 149. Place the
compass a short distance from the end of the core of the coil
H (No. 89). Close the circuit, and as soon as the needle gets
part way around open it again, closing it at the proper time
to give the needle a new impulse. The speed can be regulated,
somewhat, by changing its distance from the core. A key may be
used in place of a reverser.
(B) Reverse the direction of rotation.
_=455. Discussion of Exps. 189-190.=_ We have, in these experiments,
the key to the action of electric motors. By properly opening and
closing the circuit, the rotary motion can be kept up as long as
current is supplied. If a small pulley were attached to the top of
the compass-needle in Exp. 190, a tiny belt could be attached, and we
should have a machine that could do, perhaps, a fly-power of work. (See
Electric Motors.)
CHAPTER XXVII.
APPLICATIONS OF ELECTRICITY.
_=456. Things Electricity Can Do.=_ Among the almost countless things
that electricity can do are the following: It signals without wires. It
drills rock, coal, and teeth. It cures diseases and kills criminals. It
protects, heats, and ventilates houses. It photographs the bones of the
human body. It rings church bells and plays church organs. It lights
streets, cars, boats, mines, houses, etc. It pumps water, cooks food,
and fans you while eating. It runs all sorts of machinery, elevators,
cars, boats, and wagons. It sends messages with the telegraph,
telephone, and search-light. It cuts cloth, irons clothes, washes
dishes, blackens boots, welds metals, prints books, etc., etc.
As this book deals almost exclusively with experiments, to be performed
with simple, home-made apparatus, space cannot be given for a
discussion of the many instruments and machines which make electricity
a practical every-day thing. (See "Things A Boy Should Know About
Electricity.") The principles upon which a few important instruments
depend, however, will be given.
[Illustration: Fig. 150.]
=EXPERIMENT 191. To study the action of a simple "telegraph
sounder."=
=457. Directions.= (A) Arrange as in Fig. 150. The
electromagnet is supported upon its base, as directed in § 407.
Coil H, K, and D C are joined in series. The iron strip, I, can
be held by the left hand, while K is worked with the right.
(B) Press the key, closing the circuit for different lengths of
time, and note that the _armature_, I, responds exactly to the
motions at K.
_=458. Discussion.=_ The downward click makes a distinct sound, and in
regular instruments the armature is allowed to make an upward click,
also. The time between the two clicks can be short or long to represent
_dots_ or _dashes_, which, together with _spaces_, represent letters.
(For telegraph alphabet, and complete directions for making and
connecting a home-made telegraph line, see Apparatus Book.)
[Illustration: Fig. 151.]
_=459. Telegraph Line; Connections.=_ Fig. 151 shows complete
connections for a home-made telegraph line. The capital letters are
used for the right side, R, and small letters for the left side, L.
Gravity cells, B and b, are used. The _sounders_ S and s, and the
_keys_, K and k, are shown by a top view, or plan. The broad black
lines of S and s represent the armatures, which are directly over the
electromagnets. The keys have switches, E and e.
The two stations, R and L, may be near each other or in different
houses. The _return wire_, R W, passes from the copper of b to the zinc
of B. This is important, as the cells must help each other; that is,
they are in series. The _line wire_, L W, passes from one station to
the other, and the return may be through a wire, R W, or through the
earth; but for short lines a return wire is best.
_=460. Operation of Line.=_ Suppose R (right) and L (left) have a line.
Fig. 151 shows that R's switch, E, is open, while e is closed. The
entire circuit, then, is broken at but one point. As soon as R presses
his key, the circuit is closed, and the current from both cells rushes
around from B through K, S, L W, s, k, b, R W and back to B. This makes
the armatures of S and s come down with a click at the same time. (See
Exp. 191.) As soon as the key is raised, the armatures raise, making
the up-click. (See § 458.) As soon as R has finished, he closes his
switch, E. L then opens e and answers R. Both E and e are closed when
the line is not in use, so that either can open his switch at any time
and call up the other. Closed circuit cells are used for such lines. On
large lines the current from a dynamo is used.
[Illustration: Fig. 152.]
=EXPERIMENT 192. To study the action and use of the "relay" on
telegraph lines.=
=461. Directions.= (A) Arrange as in Fig. 152. Place K and D C
at one end of the table to represent the sending station. At
the other end of the table place E, which is the electromagnet
of the relay, and H, the electromagnet of the sounder. Connect
the ends of E with K and D C, L W being the line wire, and R W
the return. In practice, the return is through the earth. The
relay armature, R A, should vibrate towards E every time K is
pressed. C is a piece of copper against which R A presses each
time it is attracted by E, and this closes what is called the
local circuit. Connect the poles of another battery, L B, with
C and H, and the other end of coil H with R A. The sounder
armature, S A, should be arranged as in Exp. 191. Small springs
are shown on the two armatures, and these keep them away from
the cores when the circuits are open.
(B) Fasten the parts to a board, and study the connections and
action of this home-made outfit.
=462. The Relay= replaces the sounder in the line wire circuit,
and its coils are usually wound with many turns of fine
wire, so that a feeble current will move its nicely adjusted
armature. Owing to the large resistance of long telegraph
lines, the current is weak when it reaches a distant station,
and not strong enough to work an ordinary sounder. The current
passes back from the relay to the sending station through the
earth. The relay armature acts as an automatic key to open and
close the local circuit, which includes also a battery and
sounder. The line current does not enter the sounder. (See
"Things A Boy Should Know About Electricity.")
[Illustration: Fig. 153.]
=EXPERIMENT 193. To study the action of a two-pole telegraph
instrument.=
=463. Directions.= (A) Arrange as in Fig. 153. Connect the two
coils to the connecting plates, as described in § 408. Join a
strip of copper Cu with wire 2 leading from D C, and join the
zinc of D C to M. The ends of wires 1 and 3 should be near Cu
but they must not touch it. If Cu be slightly curved so that
its ends are raised above the table, the ends of wires 1 and
3 may be put directly under the ends of Cu; each half of Cu
can then be used as a key. Two armatures, A and B, should be
held as shown. D C can be placed at one side, of course, its
terminals being joined to M and Cu.
(B) Press first one end and then the other of Cu, so that the
current will pass through H or E at will.
(C) Paste pieces of paper to the armatures, the left one being
marked with a dot, and the other with a dash. The one who
sends the message can make dots or dashes at the instrument by
pressing the proper key. This form of instrument can be easily
made by boys, and the messages are more easily read by the eye
than by the ear, as in regular sounders.
[Illustration: Fig. 154.]
=EXPERIMENT 194. To study the action of a simple "single needle
telegraph instrument."=
=464. Directions.= (A) Arrange as in Fig. 154. Stick a pin on
each side of the N pole of the galvanoscope-needle through the
degree-card, so that the needle can make but part of a turn
when the circuit is closed.
(B) Touch one lever of the reverser C R, then the other, to
see whether connections are right. The needle should be forced
against one pin and then against the other. If motions to
the left represent _dots_, and those to the right _dashes_,
combinations of dots and dashes can be used for letters as in
the "sounder" (Exp. 191).
(C) Arrange the apparatus shown in Fig. 122 so that messages
can be sent.
[Illustration: Fig. 155.]
=EXPERIMENT 195. To study the action of a simple automatic
"contact breaker," or "current interrupter."=
=465. Directions.= (A) Arrange as in Fig. 155. Slip a spring
connector attached to wire 1 upon the iron strip I, a short
distance from its end. Hold the left-hand end of I firmly in
one hand, and with the other hold the connector on wire 2 just
above that on 1. The right-hand end of I should be just above
the core of H.
(B) Allow the current to pass through the circuit by touching
the two connectors together gently. Does the armature make one
click, as in the telegraph sounder, or does it vibrate rapidly?
(C) Try the connectors in various positions on I.
_=466. Automatic Current Interrupters=_ are used on bells, buzzers,
induction coils, etc. The principle upon which they work is shown in
the above experiment (Fig. 155). The current, as it comes from the
carbon of D C, is obliged to stop when it reaches I, unless the two
connectors touch. As soon as the current passes, I is pulled down
and away from the upper connector, and this breaks the circuit. I,
being held firmly in the hand, immediately springs back to its former
position, closing the circuit. The rapidity of the vibrations depends
somewhat upon the position of the connectors upon I. In regular
instruments, a platinum point is used where the circuit is broken; this
stands the constant sparking at that point.
[Illustration: Fig. 156.]
=EXPERIMENT 196. To study the action of a simple "electric
bell," or a "buzzer."=
=467. Directions.= (A) Fig. 156 shows the circuit explained in
Exp. 195, with a key or push-button put in, so that the circuit
can be closed at a distance from the vibrating armature.
(B) Have a friend work the key while you hold I and wires 1 and
2 as directed in Exp. 195. The circuit must not be broken at
two places, of course, so begin by holding the two connectors
together. The armature should vibrate rapidly each time K is
pressed.
_=468. Electric Bells and Buzzers=_ are very nearly alike in
construction; in fact, you will have a buzzer by removing the bell from
an ordinary electric bell. Buzzers are used in places where the loud
sound of a bell would be objectionable.
By placing a bell near the end of the vibrating armature (Fig. 156), so
that the bell would be struck by it at each vibration, we should have
an electric bell. By making the wires 1 and 3 long, the bell or buzzer
can be worked at a distance. (See Apparatus Book, Chapter XV, for
Home-made Bells and Buzzers.)
[Illustration: Fig. 157.]
=EXPERIMENT 197. To study the action of a simple telegraph
"recorder."=
=469. Directions.= (A) Cut from a tin box, or can, a piece of
tin about 4 in. long and 1-1/2 in. wide. Bend this double to
make two thicknesses. This will serve as an armature I (Fig.
157). Nail to one end of I a small spool, S, and into this put
a short length of lead-pencil, P, which may be held firmly in S
by wrapping a little paper around it. Connect the ends of coil
H to a key and cell as in Fig. 156.
(B) Hold or fasten I in place, and have a friend make dots and
dashes at the key, while you draw a piece of paper past the end
of P. A little adjusting will be necessary to get the pencil to
write only while the circuit is closed. In regular machines all
the parts are automatic.
[Illustration: Fig. 158.]
=EXPERIMENT 198. To study the action of a simple "annunciator."=
=470. Directions.= (A) Arrange as in Fig. 158. Fasten the
two electromagnets, H and E, to a board or a piece of stiff
cardboard. They may be held in place by passing strings over
them and through the board, tying on the other side. The ends
of coils H and E should be joined to pieces of tin, A, B, C, by
means of connectors. K and K are keys or push-buttons, which
in real instruments are in different rooms. Two steel pens may
be swung on pins a short distance from the ends of the cores,
so that their lower ends will be attracted to the cores the
instant the current passes through them. The residual magnetism
should hold them against the cores until removed. Hairpins,
nails, or needles can be used instead of pens.
(B) Press first one K and then the other to see whether your
connections are correct.
_=471. Annunciators.=_ There are many forms of annunciators in use to
indicate, in a hotel for example, a certain room when a bell rings at
the office. If a bell be included in the circuit between D C and A
in Fig. 158, it will ring each time a key is pushed. This will call
attention to the fact that some one has rung, and the annunciator will
show the location of the special call. Large instruments are made with
hundreds of electromagnets, each one answering to a special room. The
instrument should be set, of course, after each call. A nail or screw
wound with insulated wire can be used for the electromagnets of a
home-made annunciator.
=EXPERIMENT 199. To study the shocking effects of the "extra
current."=
=472. Directions.= (A) Use the two electromagnets joined to
the connecting plates (Fig. 132), to generate a self-induced
or extra current. Connect R of Fig. 132 with the zinc of a dry
cell, and between L and the carbon of the cell place a key; in
other words, join the electromagnets, cell, and key in series.
Two good cells in series can be used to advantage.
(B) Wet the ends of two fingers of the left hand, press one
upon L and the other on R, thus making a shunt with your hand.
With the right hand work the key rapidly. If the current is
strong enough you should feel a slight shock in the fingers
each time the circuit is broken. The extra current (§ 444)
causes the shock as it shoots through the fingers.
(C) If you have electric bells or telegraph sounders use them
for this experiment.
_=473. Induction Coils=_ are instruments for producing induced currents
of high E. M. F. The apparatus shown in Fig. 141 forms a simple
induction coil. The _primary_ coil is made of coarser wire and has less
turns of wire than the _secondary_ coil. The current in the primary
circuit is usually interrupted by an _automatic interrupter_ (Exp.
195), thus producing an alternating current in the secondary coil,
the voltage of which depends upon the relative number of turns in the
two coils. Induction coils are used in telephone work, for medical
purposes, for X-ray work, etc., etc.
(For Home-made Induction Coils see Apparatus Book, Chapter XI.)
[Illustration: Fig. 159.]
=474. Action of Induction Coils.= Fig. 159 shows a top view of
one of the home-made induction coils described, in full, in the
Apparatus Book. Wires 5 and 6 are the ends of the primary coil,
while wires 7 and 8 are the terminals of the secondary coil.
The battery wires should be joined to binding-posts W and X,
and the handles to Y and Z. Fig. 160 shows the details of the
automatic interrupter which is placed in the primary circuit.
[Illustration: Fig. 160.]
If the current enters at W, it will pass through the primary
coil and out at X, after going through 5, R, F, S I, B, E and
C. The instant the current passes, the bolt becomes magnetized;
this attracts A, which pulls B away from the end of S I, thus
automatically opening the circuit. B at once springs back to
its former position against S I, as A is no longer attracted;
the circuit being closed, the operation is rapidly repeated.
(For commercial forms and uses of induction coils see "Things A
Boy Should Know About Electricity.")
_=475. Transformers=_, like induction coils, are instruments for
changing the E. M. F. and strength of currents. There is very little
loss of energy in well-made transformers. They consist of two coils of
wire on the same core; in fact, an induction coil may be considered
a transformer. If the secondary coil has 100 times as many turns of
wire as the primary, a current with an E. M. F. of 100 volts can
be taken from the secondary coil, when the E. M. F. of the current
passing through the primary is 1 volt; but the _strength_ (amperes) of
the secondary current will be but one-hundredth that of the primary
current. By using the coil of fine wire as the primary, the E. M. F. of
the current that comes from the other coil will be but one-hundredth
that in the fine coil. It will have 100 times its strength, however.
Continuous currents from cells or dynamos must be interrupted, as
in induction coils, to be transformed from one E. M. F. to another.
Transformers are now largely used in lighting and power circuits, etc.
(See "Things A Boy Should Know About Electricity.")
_=476. The Dynamo.=_ We saw in the Exps. of Chapter XXV. that currents
of electricity can be generated in a coil of wire (closed circuit)
by rapidly moving it through the field of a magnet. As shown by the
experiments, this can be accomplished in many ways. The dynamo is a
machine for doing this on a large scale, the coils being given a rotary
motion in a very strong magnetic field; and as the number of lines of
force that cut the coil is constantly changing, there is a current in
the coil as long as power is applied, and this current is led from the
machine by proper devices.
_The dynamo is a machine for converting mechanical energy into an
electric current, through electromagnetic induction._
If a loop of wire (Fig. 161) be so arranged on bearings at its ends
that it can be made to revolve, a current will flow through it in
one direction during one-half of the revolution, and in the opposite
direction during the other half, it being insulated from all external
conductors. Such a current inside of the machine would be of no value;
it must be led out to external conductors. Some sort of sliding contact
is necessary to connect a revolving conductor with a stationary one.
[Illustration: Fig. 161.]
[Illustration: Fig. 162.]
Fig. 162 shows the ends of a coil joined to two rings, X, Y, which
are insulated from each other, and which rotate with the coil. Two
stationary pieces of carbon, A, B, called _brushes_, press against
the rings, and to these are joined wires which complete the circuit,
and which lead out where the current can do work. The arrows show the
direction of the current during one-half of a revolution. The rings
form a _collector_, and this arrangement gives an alternating current.
[Illustration: Fig. 163.]
In Fig. 163 the ends of the coil are joined to the two halves of a
cylinder. These halves, X and Y, are insulated from each other and
from the axis. The current flows from X onto the brush A, through some
external circuit where it does work, and thence back through brush
B onto Y. By the time that Y gets around to A the direction of the
current in the loop has reversed, so that it passes towards Y; but it
still enters the outside circuit through A because Y is then in contact
with A. This device is called a _commutator_, and it allows a constant
or direct current to leave the machine.
In regular machines there are many loops of wire and several segments
to the commutator. The rotating coils are wound upon an iron core,
so that the lines of force, in passing from one pole to the other,
will meet with as little resistance as possible. The coils, core, and
commutator, taken together, are called the _armature_. The magnets
which furnish the field are called the _field-magnets_. These are
electromagnets, the current from the dynamo, or a part of it, being
used to excite them. There are many forms of dynamos, and many ways
of winding the armature and field-magnets, but space will not permit
a discussion of them here. (See "Things a Boy Should Know About
Electricity.")
_=477. The Electric Motor.=_ Experiments have shown that motion can be
produced by the electric current in many ways. The galvanoscope may be
considered a tiny motor.
_An electric motor is a machine for transforming electric energy into
mechanical power._
While the electric motor is similar in construction to the dynamo, it
is opposite to it in action. Motors receive current and produce motion.
The motion is a rotary one, the power being applied to other machines
by means of belts or gears.
[Illustration: Fig. 164.]
=EXPERIMENT 200. To study the action of the telephone.=
=478. Directions.= (A) Join the ends of coil H (Fig. 164) to
the astatic galvanoscope. Move magnet M back and forth in front
of the soft iron core, while H is held in position. Watch the
needle. Imagine that vibrations in the air caused by the voice
are strong enough to give M a slight motion to and fro, and you
can see how a current would be sent through the galvanoscope by
speaking against M.
_=479. The Telephone=_ is an instrument for reproducing sounds at a
distance, and electricity is the agent by which this is generally
accomplished. The part spoken to is called the _transmitter_, and the
part which gives the sound out again is called the _receiver_. Sound
itself does not pass over the line. Although the same apparatus may be
used for both transmitter and receiver, they are generally different in
construction.
[Illustration: Fig. 165.]
_=480. The Bell or Magneto-transmitter=_ generates its own current,
and is, strictly speaking, a dynamo that is run by the voice. You have
seen, by experiments, that a current can be generated in a coil of wire
by moving a magnet back and forth in front of its soft iron core. In
the telephone this process is reversed, soft iron in the shape of a
thin disc (D, Fig. 165) being made to vibrate by the voice immediately
in front of a coil having a permanent magnet, M, for a core.
The soft iron diaphragm is fixed near, but it does not touch the
magnet. The coil consists of many turns of fine insulated wire. The
current generated is an alternating one and exceedingly feeble; in
fact, it can not be detected by a galvanoscope.
_=481. The Receiver=_ has the same construction as the bell
transmitter, and receives the currents from the line. As the diaphragm
is always attracted by the magnet, it is under a constant strain.
This strain is increased when a current passes through the coil in a
direction that adds strength to the magnet, and decreased when the
current weakens the magnet.
When the current through the coil is always in the same direction,
but varies in strength, the diaphragm will vibrate on account of the
varying pull upon it.
[Illustration: Fig. 166.]
When the current through the coil is an alternating one, the same
result is obtained, as the magnet gets weaker and stronger many times
per minute. Fig. 166 shows two bell instruments joined, either being
used as the transmitter and the other as the receiver.
_=482. The Carbon Transmitter=_ does not in itself generate a current
like the magneto-transmitter; it merely produces changes in the
strength of a current that flows through it, and that comes from some
outside source.
In Fig. 167, X and Y are two carbon buttons, X being attached to the
diaphragm, D. Button Y presses gently against X. When D is caused to
vibrate by the voice, X is made to press more or less against Y, and
this allows more or less current to pass through the circuit, in which
also is the receiver, R. This direct undulating current changes the
pull upon the diaphragm of R, causing it to vibrate and reproduce the
original sounds spoken into the transmitter.
[Illustration: Fig. 167.]
_=483. Induction Coils in Telephone Work.=_ As the resistance of
telephone lines is large, a current with a fairly high E. M. F. is
desired. While the current from one or two cells is sufficient to
work the transmitter, it is not strong enough to force its way over a
long line. To get around this difficulty an induction coil is used to
transform the battery current, that flows through the transmitter and
primary coil, into a current with a high E. M. F. that can go into the
main line and force its way to a distant receiver.
The battery current in the primary coil is undulating, but always in
the same direction, the magnetic field around the core getting weaker
and stronger. This causes an alternating current in the secondary coil
and main line.
[Illustration: Fig. 168.]
Fig. 168 shows the two coils, P, S, of the induction coil. The primary,
P, is joined in series with a cell and transmitter. The secondary
coil, S, is joined to the receiver. One end of S can be grounded, the
current completing the circuit through the earth and into the receiver
through another wire entering the earth. There are many forms of
transmitters. (See "Things a Boy Should Know About Electricity.")
_=484. Electric Lighting and Heating.=_ Whenever resistance is offered
to the electric current, heat is produced. By proper appliances, the
heat of resistance can be applied just where it is needed, and many
commercial processes depend upon electricity for their success. Dynamos
are used to generate currents for lighting and heating purposes. There
are two great systems of lighting, the one by _arc_ lamps and the
other by _incandescent_ lamps. (See "Things a Boy Should Know About
Electricity.")
_=485. Arc Lamps=_ produce a light when a current passes from one
carbon rod to the other across an air-space. As the current starts
through the lamp, the ends of the carbons touch, and the imperfect
contact causes resistance enough to heat the ends red-hot. They are
then automatically separated, and the current passes from one to the
other, causing the "arc." The resistance of the air-space is reduced by
the intensely heated vapor and flying particles of carbon.
_=486. The Incandescent Lamp=_ consists of a glass bulb, in which is a
vacuum, and the light is caused by the passage of a current through a
thin fibre of vegetable carbon, enclosed in the vacuum. The fibre would
burn instantly if allowed to come in contact with the air. The fibres
have a high resistance, and are easily heated to incandescence.
CHAPTER XXVIII.
WIRE TABLES.
_Copper Wire Tables_ are very convenient, and a necessity when working
electrical examples. The tables here given are taken from a dealer's
catalogue, and will be found sufficiently accurate for ordinary work.
_Explanation of Tables._ In the _first_ column are given the sizes of
wires by numbers. The B & S or American gauge is used. In the table
below is given a comparison between the B & S and the Birmingham gauges.
The _second column_ gives the diameters of wires. The diameter of No.
36 wire is 5 thousandths of an inch; the diameter of No. 24 wire is a
little over 20 thousandths or 2 hundredths of an inch.
The _third column_ contains what is called circular mils, a mil being
a thousandth of an inch. The figures in this column are obtained by
squaring those in the second; thus, for No. 36 wire, 5 × 5 = 25.
This column is useful when working examples where the squares of the
diameters are wanted. The rest of the table explains itself.
The table at the bottom gives a comparison between the fractional and
decimal parts of an inch. Space can not be given here for a series
of examples showing the many uses of this table. (See "Elementary
Electrical Examples.")
COPPER WIRE TABLES.
(Based on the
B. A. Unit.)
=====+=======+=========+=======+===================================+
Gauge| DIAM- |Sectional|Capac- | OHMS |
| ETER. | AREA | ity. | |
-----+-------+---------+-------+-----------+----------+------------+
B.&S.| In | In |In Amp-| Per | Per | Per |
No. |1000ths|Circular | eres. | 1,000 | Mile. | Pound. |
| | Mils. | | feet. | | |
-----+-------+---------+-------+-----------+----------+------------+
0000|.460 |211600. | 312. | .04906| .25903| .000077|
000|.40964 |167805. | 262. | .06186| .32664| .00012 |
00|.3648 |133079. | 220. | .07801| .41187| .00019 |
0|.32486 |105534. | 185. | .09831| .51909| .00031 |
1|.2893 | 83694. | 156. | .12404| .65490| .00049 |
2|.25763 | 66373. | 131. | .15640| .8258 | .00078 |
3|.22942 | 52634. | 110. | .19723| 1.0414 | .00125 |
4|.20431 | 41743. | 92.3 | .24869| 1.313 | .00198 |
5|.18194 | 33102. | 77.6 | .31361| 1.655 | .00314 |
6|.16202 | 26251. | 65.2 | .39546| 2.088 | .00499 |
7|.14428 | 20817. | 54.8 | .49871| 2.633 | .00792 |
8|.12849 | 16510. | 46.1 | .6529 | 3.3 | .0125 |
9|.11443 | 13094. | 38.7 | .7892 | 4.1 | .0197 |
10|.10189 | 10382. | 32.5 | .8441 | 4.4 | .0270 |
11|.090742| 8234. | 27.3 | 1.254 | 6.4 | .0501 |
12|.080808| 6530. | 23. | 1.580 | 8.3 | .079 |
13|.071961| 5178. | 19.3 | 1.995 | 10.4 | .127 |
14|.064084| 4107. | 16.2 | 2.504 | 13.2 | .200 |
15|.057068| 3257. | 13.6 | 3.172 | 16.7 | .320 |
16|.05082 | 2583. | 11.5 | 4.001 | 23. | .512 |
17|.045257| 2048. | 9.6 | 5.04 | 26. | .811 |
18|.040303| 1624. | 8.1 | 6.36 | 33. | 1.29 |
19|.03589 | 1288. | .... | 8.25 | 43. | 2.11 |
20|.031961| 1021. | .... | 10.12 | 53. | 3.27 |
21|.028462| 810. | .... | 12.76 | 68. | 5.20 |
22|.025347| 642. | .... | 16.25 | 85. | 8.35 |
23|.022571| 509. | .... | 20.30 | 108. | 13.3 |
24|.0201 | 404. | .... | 25.60 | 135. | 20.9 |
25|.0179 | 320. | .... | 32.2 | 170. | 33.2 |
26|.01594 | 254. | .... | 40.7 | 214. | 52.9 |
27|.014195| 201. | .... | 51.3 | 270. | 84.2 |
28|.012641| 159.8 | .... | 64.8 | 343. | 134. |
29|.011257| 126.7 | .... | 81.6 | 482. | 213. |
30|.010025| 100.5 | .... | 103. | 538. | 338. |
31|.008928| 79.7 | .... | 130. | 685. | 539. |
32|.00795 | 63. | .... | 164. | 865. | 856. |
33|.00708 | 50.1 | .... | 206. |1033. | 1357. |
34|.006304| 39.74| .... | 260. |1389. | 2166. |
35|.005614| 31.5 | .... | 328. |1820. | 3521. |
36|.005 | 25. | .... | 414. |2200. | 5469. |
37|.004453| 19.8 | .... | 523. |2765. | 8742. |
38|.003965| 15.72| .... | 660. |3486. |13772. |
39|.003531| 12.47| .... | 832. |4395. |21896. |
40|.003144| 9.88| .... | 1049 |5542. |34823. |
-----+-------+---------+-------+-----------+----------+------------+
=====+=======================+========================
Gauge| FEET. | POUNDS.
| |
-----+-----------+-----------+-----------+------------
B.&S.| Per | Per | Per | Per
No. | Pound. | Ohm. |1,000 feet.| Ohm.
-----+-----------+-----------+-----------+------------
0000| 1.56122|20497.7 | 640.51 |12987.
000| 1.9687 |16255.27 | 507.95 | 8333.
00| 2.4824 |12891.37 | 402.83 | 5263.
0| 3.1303 |10223.08 | 319.45 | 3225.
1| 3.94714| 8107.49 | 253.34 | 2041.
2| 4.97722| 6429.58 | 200.91 | 1282.
3| 6.2765 | 5098.61 | 159.32 | 800.
4| 7.9141 | 4043.6 | 126.35 | 505.
5| 9.97983| 3206.61 | 100.20 | 318.
6| 12.5847 | 2542.89 | 79.462 | 200.
7| 15.8696 | 2015.51 | 63.013 | 126.
8| 20.0097 | 1599.3 | 49.976 | 80.
9| 25.229 | 1268.44 | 39.636 | 50.
10| 31.8212 | 1055.66 | 31.426 | 37.
11| 40.1202 | 797.649 | 24.924 | 20.
12| 50.5906 | 632.555 | 19.766 | 12.65
13| 63.7948 | 501.63 | 15.674 | 7.87
14| 80.4415 | 397.822 | 12.435 | 5.00
15| 101.4365 | 315.482 | 9.859 | 3.12
16| 127.12 | 250.184 | 7.819 | 1.95
17| 161.29 | 198.409 | 6.199 | 1.23
18| 203.374 | 157.35 | 4.916 | .775
19| 256.468 | 124.777 | 3.899 | .473
20| 323.399 | 98.9533 | 3.094 | .305
21| 407.815 | 78.473 | 2.452 | .192
22| 514.193 | 62.236 | 1.945 | .119
23| 648.452 | 49.3504 | 1.542 | .075
24| 817.688 | 39.1365 | 1.223 | .047
25| 1031.038 | 31.0381 | .9699 | .030
26| 1300.180 | 24.6131 | .7692 | .0187
27| 1639.49 | 19.5191 | .6099 | .0118
28| 2067.364 | 15.4793 | .4837 | .0074
29| 2606.959 | 12.2854 | .3835 | .0047
30| 3287.084 | 9.7355 | .3002 | .0029
31| 4414.49 | 7.72143| .2413 | .0018
32| 5226.915 | 6.12243| .1913 | .0011
33| 6590.41 | 4.85575| .1517 | .00076
34| 8312.8 | 3.84966| .1204 | .00046
35|10481.77 | 3.05305| .0956 | .00028
36|13214.16 | 2.4217 | .0757 | .00018
37|16659.97 | 1.92086| .06003| .00011
38|21013.25 | 1.52292| .04758| .00007
39|26496.237 | 1.20777| .03755| .00004
40|33420.63 | 0.97984| .02992| .000029
-----+-----------+-----------+-----------+------------
Comparative Table of the Fractional and Decimal Parts of an Inch.
+-----------------+
| 1/64 = .015625 |
| 1/32 = .031250 |
| 3/64 = .046875 |
| 1/16 = .062500 |
| 5/64 = .078125 |
| 3/32 = .093750 |
| 7/64 = .109375 |
| 1/8 = .125000 |
| 9/64 = .140625 |
| 5/32 = .156250 |
| 11/64 = .171875 |
| 3/16 = .187500 |
| 13/64 = .203125 |
| 7/32 = .218750 |
| 15/64 = .234375 |
| 1/4 = .250000 |
| 17/64 = .265625 |
| 9/32 = .281250 |
| 19/64 = .296875 |
| 5/16 = .312500 |
| 21/64 = .328125 |
| 11/32 = .343750 |
| 23/64 = .359375 |
| 3/8 = .375000 |
| 25/64 = .390625 |
| 13/32 = .406250 |
| 27/64 = .421875 |
| 7/16 = .437500 |
| 29/64 = .453125 |
| 15/32 = .468750 |
| 31/64 = .484375 |
| 1/2 = .500000 |
+-----------------+
Comparative Table of B. and S. and B. W. Gauges in Decimal Parts of an
Inch.
+------------+--------------+-------------+
|Birmingham | American | No. of |
|Wire Gauge. | (B. and S.) | Wire Gauge. |
| | Wire Gauge. | |
+------------+--------------+-------------+
| 0000 | .46 | .454 |
| 000 | .40964 | .425 |
| 00 | .3648 | .38 |
| 0 | .32486 | .34 |
| 1 | .2893 | .3 |
| 2 | .25763 | .284 |
| 3 | .22942 | .259 |
| 4 | .20431 | .238 |
| 5 | .18194 | .22 |
| 6 | .16202 | .203 |
| 7 | .14428 | .18 |
| 8 | .12849 | .165 |
| 9 | .11443 | .148 |
| 10 | .10189 | .134 |
| 11 | .090742 | .12 |
| 12 | .080808 | .109 |
| 13 | .071961 | .095 |
| 14 | .064084 | .083 |
| 15 | .057068 | .072 |
| 16 | .05082 | .065 |
| 17 | .045257 | .058 |
| 18 | .040303 | .049 |
| 19 | .03589 | .042 |
| 20 | .031961 | .035 |
| 21 | .028468 | .032 |
| 22 | .025347 | .028 |
| 23 | .022571 | .025 |
| 24 | .0201 | .022 |
| 25 | .0179 | .02 |
| 26 | .01594 | .018 |
| 27 | .014195 | .016 |
| 28 | .012641 | .014 |
| 29 | .011257 | .013 |
| 30 | .010025 | .012 |
| 31 | .008928 | .01 |
| 32 | .00795 | .009 |
| 33 | .00708 | .008 |
| 34 | .006304 | .007 |
| 35 | .005614 | .005 |
| 36 | .005 | .004 |
| 37 | .004453 | |
| 38 | .003965 | |
| 39 | .003531 | |
| 40 | .003114 | |
+------------+--------------+-------------+
LIST OF APPARATUS
FOR
The Study of Elementary Electricity and Magnetism by Experiment.
The =100= pieces of apparatus in the following list are referred to,
by number, in the experiments contained in "The Study of Elementary
Electricity and Magnetism by Experiment." This list is furnished
to give those who wish to make their own apparatus an idea of the
approximate size, etc., of the various articles used. The author is
preparing a price catalogue of the articles included in this list,
and of odds and ends needed in the construction of simple, home-made
apparatus.
=No. 1.= A package of 25 steel sewing-needles. To be suitable for
experiments in magnetism, these should be of good, hard steel, and not
too thick.
=No. 2.= A flat cork, about 1 in. in diameter and 3/8 in. thick.
=No. 3.= A candle for annealing steel.
=No. 4-15.= One dozen assorted annealed iron wires, from 1 in. to 6 in.
in length. The iron should be very soft.
=No. 16.= One English horseshoe magnet, 2-1/2 in. long, best quality.
=No. 17.= A small box of iron filings from soft iron.
=No. 18.= A compass (Fig. 5). The needle swings very freely; it is
enclosed in a wooden pill box, the cover of which forms the support.
=No. 19, 20.= Two soft steel wire nails, 2 in. long.
=No. 21, 22.= Two pieces of spring steel, about 3 in. long and 3/8 in.
wide, to be magnetized by the student and used as bar magnets.
=No. 23.= An iron ring, or washer, about 7/8 in. in diameter.
=No. 24.= A sifter for iron filings. This consists of a pasteboard pill
box: Prick holes through the bottom with a pin.
=No. 25.= A thin, flexible piece of spring steel, about 3 in. long and
1/8 in. wide.
=No. 26, 27.= Two ebonite sheets (E S, Fig. 34), each 4 in. square.
These are made with a special surface. They are very much better than
the ordinary smooth ebonite.
=No. 28.= One ebonite rod (E R, Fig. 34), 3-1/2 in. long, with special
surface.
=No. 29.= One ebonite rod, 1-3/4 in. long, with special surface, used
to support the insulating table, No. 43 (I T, Fig. 32).
=No. 30.= One piece of flannel cloth, 7 in. square.
=No. 31.= Six sheets of tissue-paper, each 4 in. square.
=No. 32.= A few feet of white cotton thread.
=No. 33.= A few feet of black silk thread.
=No. 34.= One support base (S B, Fig. 56). This is of thin wood, about
3-3/4 in. by 6-1/2 in., to one end of which is fastened a spool for
holding the support rod (No. 35).
=No. 35.= One support rod (S R, Fig. 56), 7 in. long and 5/16 in.
in diameter. This rod has a hole in each end. The small hole is for
holding the support wire (No. 36); the large hole is for the ebonite
rod (No. 29).
=No. 36.= One support wire (S W, Fig. 144).
=No. 37.= One wire swing (W S, Fig. 29).
=No. 38.= One sheet of glass, 4 in. square.
=No. 39.= One bent hairpin (H P, Fig. 32).
=No. 40.= Bottom of flat box (B F B, Fig. 32), 3-5/8 in. in diameter.
=No. 41.= Top of flat box (T F B, Fig. 33).
=No. 42.= One electrophorus cover (E C, Fig. 34), 3-5/8 in. in
diameter. This has rounded edges, and a small tube is riveted into the
top of it to hold the insulating handle, E R.
=No. 43.= One insulating table (I T, Fig. 32). This is made the same as
No. 42, and is supported by No. 29.
=No. 44.= One insulated copper wire, 2-1/2 feet long.
=No. 45.= One rubber band (R B, Fig. 33).
=No. 46.= Six bent wire clamps (B C, Fig. 37).
=No. 47.= One tin box conductor (T B, Fig. 42). This cylindrical
conductor is about the size of an ordinary baking powder box.
=No. 48.= One hairpin discharger for the condenser.
=No. 49.= Two sheets of aluminum-leaf for the leaf electroscope (Fig.
57) and other experiments.
=No. 50.= One bent wire (H P, Fig. 57) used in connection with the leaf
electroscope.
=No. 51.= A dry cell, ordinary size about 7 in. high and 2-1/2 in. in
diameter.
=No. 52.= Enough mercury to amalgamate battery zincs. A wooden pill box
containing about half a thimbleful will do.
=No. 53.= A coil containing 25 feet of No. 24 insulated copper wire for
connections.
=No. 54.= One dozen spring connectors (Fig. 61) for making connections.
These are made of brass, nickel plated, and do not affect the
compass-needle.
=No. 55.= A telegraph key (Fig. 68) without switch. The metal straps
are made of aluminum; they are 1/2 in. wide, and are fastened to a neat
wooden base.
=No. 56.= Three metal plates, each about 2 in. by 3/4 in., on which
spring connectors (No. 54) are to be pushed in order to join two wires.
=No. 57.= A current reverser (Fig. 69). The straps are made of aluminum
and are fastened to a neat wooden base.
=No. 58.= A galvanoscope (Fig. 72) including a degree-card (No. 99).
The cardboard coil-support, C S, is 5 × 6-1/4 in., and the hole in it
is 3-3/8 in. in diameter. The coil is 4-1/4 in. in diameter, made of
No. 24 insulated copper wire.
=No. 59.= An astatic galvanoscope (Fig. 77). The whole may be taken
apart and mailed in the containing box, B, which is 4-3/8 × 3-1/8 × 1
in. The coil is made of No. 31 wire, and has a resistance of about 5
ohms. Spring connectors are used to join a wire to the apparatus by
pushing the connectors into the tubular binding-posts, L and R.
=No. 60-63.= Four strips of sheet zinc, 4 in. by 1/2 in., not
amalgamated.
=No. 64.= A carbon rod, 4 in. long (Fig. 81).
=No. 65, 66.= Two glass tumblers (Fig. 81).
=No. 67, 68.= Two strips of sheet copper, 4 in. by 1/2 in. (Fig. 85).
=No. 69.= One galvanized iron nail.
=No. 70, 71.= Two wooden cross-pieces (Fig. 85).
=No. 72.= One dozen brass screws, 5/8 in. long, size No. 5, with round
heads.
=No. 73.= A porous cup (P C, Fig. 87) that will stand inside of the
tumblers (No. 65).
=No. 74.= A zinc rod, about 3/8 in. in diameter, like those used in
Leclanché cells.
=No. 75.= A sheet copper plate for the two-fluid cell (C, Fig. 87).
This is 2 in. wide; it nearly surrounds the porous cup, and is
supported upon the edge of the tumbler by a narrow strip, A, with which
connections are made by spring connectors (No. 54).
=No. 76.= One strip of sheet iron, 4 in. by 1/2 in.
=No. 77, 78.= Two strips of sheet lead, 4 in. by 1/2 in.
=No. 79.= A resistance coil (Fig. 94). The coil is made of No. 24
insulated copper wire; it has a resistance of 2 ohms (nearly) and is
fastened to a cardboard base. It is so arranged that either one or two
ohms can be used at will.
=No. 80.= A Wheatstone's bridge (Fig. 103), including a scale (No.
100). The aluminum straps, 1, 2, 3, are fastened to a neat wooden base,
10 in. long by 2 in. wide. A No. 28 German-silver wire is used for the
bridge.
=No. 81.= A piece of No. 30 uncovered German-silver wire, 2.1 meters
long, used for resistance (Fig. 96).
=No. 82.= A piece of No. 28 uncovered German-silver wire, 2.1 meters
long.
=No. 83-85.= Three plate binding-posts, consisting of bent straps of
sheet aluminum (X, Y, Z, Fig. 96).
=No. 86.= Two ounces of copper sulphate, commonly called bluestone. The
crystals may be kept in a large wooden pill box.
=No. 87.= One dozen copper washers.
=No. 88.= One combination rule, 1 ft. long, marked with English and
metric systems.
=No. 89.= A hollow coil of No. 24 insulated copper wire (Fig. 130). The
spool, on which the wire is wound, has a hole for a five-sixteenths
inch core. It is turned down thin, so that the wire is near the
core. The coil is about 1-1/8 in. long and 1 in. in diameter. Spring
connectors are joined to the ends of the coil.
=No. 90.= A hollow coil of No. 25 insulated copper wire, similar to No.
89, with spring connectors attached to its ends.
=No. 91.= Carbon rod for electroplating.
=No. 92, 93.= Two soft iron cores, with screws (I C, Fig. 130). These
cores are 5/16 in. in diameter, and have a threaded hole in one end for
fastening them to No. 94.
=No. 94.= A tin box with three holes punched in its top (Fig. 132).
This serves as a base, as well as a yoke, for the two electromagnets,
A, B, shown in plan.
=No. 95.= Combination connecting plates (Fig. 132). Three aluminum
straps are fastened to a wooden base. They are turned up at their ends
so that spring connectors can be easily pushed upon them.
=No. 96.= One long iron core (L I C, Fig. 140). This is of soft iron,
5/16 in. in diameter, and long enough to pass through both coils (No.
89, 90).
=No. 97.= Bar magnet, about 4 in. long and 5/16 in. in diameter.
=No. 98.= Coil of insulated wire wound on a soft iron core, to act as
a primary coil for induction experiments. This coil fits inside of the
hollow coils (Nos. 89, 90).
=No. 99.= A printed degree-card for the galvanoscope (No. 58). This is
printed on stiff cardboard, about 3 in. in diameter.
=No. 100.= A printed scale for the Wheatstone's bridge (No. 80). This
is printed on stiff paper. The scale is 8 in. long, and is divided into
10 large divisions, each of which is subdivided into 10 parts, thus
making 100 parts in all.
INDEX.
Numbers refer to paragraphs. See Table of Contents for the various
experiments.
Abreast, arrangement of cells, 365.
Accumulators. (See storage cells.)
Action, local, 273.
Air, as insulator, 144, _a_.
Alternating currents, 443.
Amalgamating, 257, 274.
Amber, 107.
Ammeter, 353.
Ampere, the, 351, 357.
Ampere's rule, 386.
Annealing, 6.
Annunciators, 471.
Anode, 373, 378.
Applications of electricity, Chap. XXVII.
Arc lamp, 485.
Arrangement, of cells, 363 to 368.
Armature, the, 11, 78, 476.
Astatic needles, 251, 253, 254;
galvanoscope, 252, 256.
Atmospheric electricity, Chap. XIII., 217;
causes of, 221.
Attraction, mutual, 111;
and repulsion, laws of magnetic, 29;
electric, laws of, 121.
Aurora borealis, 223.
Batteries, Chap. XV.;
storage, 382.
Bell, electric, 468.
Bell telephone, 480.
Bichromate cell, 289.
Bound electrification, 162, 191.
Breaking a magnet, 51.
Bridge, Wheatstone's, 324 to 330.
Brushes, 476.
Buzzers, electric, 468.
Cable, submarine, as condenser, 182.
Capacity, inductive, 169;
electrical, 176, 178.
Carbon, transmitter, 482;
electroscope, 114.
Cathode, 373.
Cell, galvanic, Chap. XV.;
arrangement of, 363, 364, 365, 368;
chemical action in, 270, 271;
direction of current in, 268;
local action in, 273;
open and closed circuit, 286;
polarization of, 278;
poles of, 269;
simple, 275;
secondary, 382;
single-fluid, 275;
two-fluid, 281, 285;
various galvanic, 286 to 291.
Charge, in condenser, 195;
residual of condensers, 197.
Charging conductors, Chap. VIII.
Chemical action, 369.
Chemical effects of current, Chap. XXI.
Circuit, electric, 266;
divided, 293;
short, 295.
Coercive force, 44, 46.
Coils, 390;
induction, 473, 474;
method of joining, 408;
polarity of, 392;
resistance, 309;
simple resistance, 310.
Commutator, 476.
Compass, 26;
our, 32;
needle, 243, 249.
Compound magnets, 73.
Condensation of electrification, Chap. X., 178.
Condensers, 178;
action of, 186, 191;
induction coil, 181;
submarine cables, 182.
Conductive discharge, 149, 184.
Conductors, 126, 129, 133;
hollow and solid, 153;
and insulators, relation between, 133;
and non-conductors, 312.
Connections, electrical, 226 to 230.
Contact breaker, Exp. 195;
§ 466.
Convective discharge, 149.
Copper sulphate solution, 283.
Cores, of electromagnets, 397.
Coulomb, the, 354.
Current electricity, Part III.
Current, 144, _a_, 264;
detectors, 232, 239;
direction of in cell, 268;
direct and alternating, 443;
extra, 444;
interrupters, 466;
primary and secondary, 441;
measurement of, 352;
reverser, 235, 237;
strength of, Chap. XX., 350, 358, 362 to 365;
unit of, 351.
Daniell cell, 290.
Declination, 84.
Depolarizers, 280, 282.
Detectors, current, 232, 239.
Diamagnetic bodies, 15.
Dielectric, 184, 191, 195.
Dielectrics, 166.
Dip, 86.
Direct currents, 428, 443.
Dischargers, 188.
Discharges, kinds of, 149.
Divided circuits, 293, 323.
Dry cells, 288.
Dynamo, 435, 476.
Earth's magnetism, 83, 92, 93.
Electric, bells, 468;
chime, 193;
circuit, 266, Chap. XVI.;
current, 144, _a_, 264;
density, 155;
field, 156;
horse-power, 355;
lighting, 484;
machines, static, 216;
motor, 477;
polarization, 159;
resistance, Chap. XVIII.;
wind, 155.
Electricity, static, Part II.;
Current, Part III.;
Applications of, Chap. XXVII., 456;
kinds of, 100;
derivation of name, 107;
Atmospheric, Chap. XIII., 217.
Electrification, Chap. VI., 103, 116, 132, 134;
and heat, 104;
condensation of, Chap. X.;
escape of, 155;
free and bound, 162;
induced, Chap. IX.;
kinds of, 120;
of earth, 222;
source of in cells, 265;
theories about, 145;
two kinds of, 120, 211.
Electrics and non-electrics, 134.
Electrified bodies, 102, 107.
Electrodes, 269.
Electromagnetism, Chap. XXII., 383.
Electromagnets, Chap. XXIII., 396;
cores of, 397;
horseshoe, 405.
Electromotive force, 144, Chap. XVII., 296, 300, 303;
measurement of, Exp. 140;
of polarization, 373, 382;
series, 301;
unit of, 297.
Electrophorus, 138;
action of, 171, 172;
our, 139.
Electrolysis, 370.
Electrolyte, 370.
Electroplating, 376, 378.
Electroscope, action of, 206, 208;
carbon, 114;
pith-ball, 200;
our leaf, 201, 202.
Electroscopes, Chap. XI.
Electrotyping, 379.
Equator of magnet, 13.
Equipotential points, 326.
External resistance, 307, 368.
Extra current, 444;
Exp. 199.
Field, electric, 156;
magnetic, Chap. IV., 62, 80;
magnets, 476.
Figures, magnetic, 64;
permanent, 417.
Force, 103;
lines of magnetic, 64, 73, 80, 156;
lines of electric, 156;
lines of about a wire, 385.
Franklin, Benjamin, 218.
Free electrification, 162.
Frictional electricity, Part II.
Fulminating panes, 180.
Galvanic cells, Chap. XV., 265;
chemical action in, 270;
various kinds of, 286 to 291.
Galvanoscope, 240 to 249.
Glass, as insulator, 136.
Gold-leaf electroscope, 200, 209.
Gravity cell, 291.
Hardening steel, 8, 10.
Heat, effect on resistance, 343;
effect on magnet, 49.
Horse-power, electric, 355.
Horseshoe magnet, 11;
advantages of, 82;
electromagnets, 405.
Hydrogen, 260, 262, 271, 278, 279, 373.
Inclination of needle, 86.
Induced currents, Chap. XXV.;
and work, 429;
and lines of force, 432, 435, 438;
direction of, 439.
Induced magnetism, Chap. III.
Induction coils, 473;
action of, 474;
condensers of, 181;
with telephone, 483.
Induction, electromagnetic, 426;
laws of, 440;
static, theory of, 159;
successive, 168.
Inductive capacity, 169.
Insulators, Chap. VII., 125.
Internal resistance, 307, 314, 358, 362, 368.
Iron and steel, Chap. I.
Iron, hardening properties of,
Exp. 4;
impurities of, 1;
kinds of, 2;
soft, 10.
Jar, Leyden, 179.
Key, 233, 234.
Lamp, arc, 485;
incandescent, 486.
Laws, of electrification, 121;
of induction, 440;
of magnetism, 29;
of resistance, 349.
Leclanché cell, 287.
Leyden jar, 179.
Lighting, 484, 485, 486.
Lightning, 144, _a_; 218;
rods, 220.
Lines of force, about a wire, 385, 388;
electric, 156;
and induced currents, 432, 438;
magnetic, 64, 73, 74, 80, 156;
resistance to, 78, 397.
Local action, 273.
Local currents, 273.
Lodestone, 93.
Magnetic, bodies, 15;
circuits, closed, 420;
field, 62, 80;
figures, permanent, 417;
figures, 64, Exp. 161, 162, Exps. 168 to 171;
force, lines of, 64, 80, 156;
induction of the earth, 92;
needle, 26;
needles, balancing of, 88;
needle, dip of, 86;
problems, 33;
saturation, 42;
screens, 18;
tick, Exp. 160;
transparency, 18.
Magnetism, Part I.;
induced, Chap. III., 53;
residual, 44, 53;
temporary, 53;
terrestrial, Chap. V.;
theory of, 42;
of earth, 83;
laws of, 29.
Magnets, bar, 21;
compound, 73;
effect of breaking, 51;
equator of, 13, 51;
experimental, 407;
kinds of, 11;
natural, 93;
poles of, 13, 25;
practical uses of, 16.
Mercury, 274.
Motion, production of, Chap. XXVI., 445, 452, 455.
Motors, electric, 477.
Mutual attractions, 111.
Natural magnets, 93.
Needle, astatic, 251, 253, 254;
magnetic, 26, 32.
Negative electrification, 120.
Neutral bodies, 102.
Non-conductors, 312.
Non-electrics, 134.
North-seeking poles, 25.
Ohm, the, 308.
Ohm's law, 356.
One-fluid theory, 145.
Open and closed circuits, 266;
cells, 286.
Oxygen, 372, 373, 382.
Peltier effect, 424.
Pith-ball electroscope, 200.
Plates or elements, 267.
Polarization of cells, 278;
effects of, 279;
electric, 159, 164;
electromotive force of, 373;
magnetic, 56;
remedies for, 280.
Poles, 13, 25, 64, 92;
consequent, 39;
of coils, 392;
of electrodes, 269;
reversal of, 35;
rule for, 31.
Pole pieces, 56.
Positive electrification, 120.
Potential, 133,144;
energy, 103.
Primary current, 441.
Proof-plane, 209.
Quantity, unit of, 354.
Recorder, Exp. 197.
Relay, telegraph, 462.
Repulsion, laws of electrostatic, 121;
laws of magnetic, 29.
Residual, charge in condenser, 197;
magnetism, 44;
magnetism of core, Exp. 159.
Resistance, coils, 309;
effect of heat on, 343;
electrical, Chap. XVIII., 305, 319, 321;
external and internal, 307, 362, 368;
internal, 314, 358;
laws of, 349;
to lines of force, 78;
measurement of, Chap. XIX.;
unit of, 308.
Retentivity, 44, 46.
Reverser, current, 235, 237.
Rheostat, simple, 344.
Saturation, magnetic, 42.
Secondary cells, 382;
current, 441.
Self-induction, 444.
Series arrangement of cells, 364.
Shocks, 188.
Short circuits, 295.
Shunts, 293.
Silk, as insulator, 136.
Single-fluid cell, 275.
Single needle telegraph, Exp. 194.
Sounder, telegraph, 458.
Spark, 144, _a_.
Static electricity, Part II.
Static electric machines, 216.
Steel, Chap. I.;
kinds of, 2;
magnetism of, 42, 46, 49.
St. Elmo's fire, 222.
Storage cells, 382.
Successive, induction, 168;
condensation, 199.
Sulphuric acid, 258, 262, 314.
Tangent galvanometer, 352.
Telegraph, line, 459, 460;
relay, 462;
single needle instrument, Exp. 194;
sounder, 458;
static, 130.
Telephone, the, 479;
Bell, 480;
carbon transmitter, 482;
with induction coils, 483;
receiver, 481.
Tempering steel, 8.
Temporary magnetism, 53.
Terrestrial magnetism, Chap. V.
Thermoelectricity, Chap. XXIV., 423.
Thermopile, 425;
home-made, 421.
Thunder, 219.
Transformers, 475.
Transmitters, 480, 482.
Two-fluid cell, 280, 281;
care of, 282;
chemical action in, 285.
Two-fluid theory of electrification, 146.
Unit of, current strength, 351;
E. M. F., 297;
of power, 355;
quantity, 354;
resistance, 308.
Variation, angle of, 84.
Varieties of electricity, 100.
Volt, the, 297.
Voltameters, 297, 353, 380.
Water, composition of, 372.
Watt, the, 355.
Wheatstone's bridge, 324 to 330.
Wind, electric, 155.
Wire tables, Chap. XXVIII.
Yoke, use of, 406.
Zero, potential, 144, _a_.
Zinc, chemical action with, 271;
with commercial, 273.
Zinc plates, reasons for amalgamating, 274.
Notes.
Notes.
ELECTRICAL BOOKS
ELECTRICAL APPARATUS
GAMES PUZZLES
EDUCATIONAL
AMUSEMENTS
[Illustration]
THOMAS M. ST. JOHN, Met. E.
A Word to Parents About Games and Educational Amusements.
Systematic play is as important as systematic work. The best games
and home amusements are as valuable to a child as school-studies; in
fact, they bring out and stimulate qualities in a child, which no
school-study can. Fascinating home amusements are as necessary as
school-books.
Boys and girls like to be busy. Their amusements should be entered
into as heartily, chosen as carefully, and purchased as willingly as
school-books.
=Games.=--JINGO and HUSTLE-BALL are good games.
They are interesting and full of action.
They arouse a child's common-sense.
They cultivate an ability to think rapidly, judge correctly, and decide
quickly.
They educate the eye and hand at the same time.
They are very simple, and may be played at once.
=Educational Amusements.=--There is a peculiar fascination about
Electricity and Magnetism, which makes these subjects appeal to every
boy and girl.
There is nothing better than science studies, to teach children
to observe and to see what they look at; besides, it is _fun_ to
experiment. "Fun With Electricity" and "Fun With Magnetism" are
educational amusements. They contain fascinating experiments and are
systematically arranged.
Juvenile Work in Electricity.
_From The Electrical Engineer, May 19, 1898._
The position that Young America is now taking in the electric and
magnetic field is very clearly shown at the Electrical Show now being
held at Madison Square Garden, by an exhibit of simple experimental
apparatus made by young boys from the Browning School, of this city.
The models shown cover every variety of apparatus that is dear to
the heart of a boy, and yet, along the whole line from push-buttons
to motors, one is struck by the extreme simplicity of design and the
ingenious uses made of old tin tomato cans, cracker boxes, bolts,
screws, wire, and the wood that a boy can get from a soap box.
The apparatus in this exhibit was made by boys 13, 14 and 15 years
of age, from designs made by Mr. Thomas M. St. John, of the Browning
School. It clearly shows that good, practical apparatus can be made
from cheap materials by an average boy. The whole exhibit is wired and
in working order, and it attracts the attention of a large number of
parents and boys who hover around to see, in operation, the telegraph
instruments, buzzers, shocking coils, current detectors, motors, etc.
Mr. St. John deserves the thanks of every boy who wants to build his
own electrical apparatus for amusement or for experimental purposes, as
he has made the designs extremely simple, and has kept constantly in
mind the fact that the average boy has but a limited supply of pocket
money, and an equally limited supply of tools.
How Two Boys Made Their Own Electrical Apparatus.
=CONTENTS:= _Chapter_ I. Cells and Batteries.--II. Battery
Fluids and Solutions.--III. Miscellaneous Apparatus and Methods
of Construction.--IV. Switches and Cut-Outs.--V. Binding-Posts
and Connectors.--VI. Permanent Magnets.--VII. Magnetic
Needles and Compasses.--VIII. Yokes and Armatures.--IX.
Electro-Magnets.--X. Wire-Winding Apparatus.--XI. Induction
Coils and Their Attachments.--XII. Contact Breakers
and Current Interrupters.--XIII. Current Detectors and
Galvanometers.--XIV. Telegraph Keys and Sounders.--XV.
Electric Bells and Buzzers.--XVI. Commutators and Current
Reversers.--XVII. Resistance Coils.--XVIII. Apparatus for
Static Electricity.--XIX. Electric Motors.--XX. Odds and
Ends.--XXI. Tools and Materials.
"The author of this book is a teacher and writer of great ingenuity,
and we imagine that the effect of such a book as this falling into
Juvenile hands must be highly stimulating and beneficial. It is
full of explicit details and instructions in regard to a great
variety of apparatus, and the materials required are all within the
compass of very modest pocket-money. Moreover, it is systematic and
entirely without rhetorical frills, so that the student can go right
along without being diverted from good helpful work that will lead
him to build useful apparatus and make him understand what he is
about. The drawings are plain and excellent. We heartily commend the
book."--_Electrical Engineer._
"Those who visited the electrical exhibition last May cannot have
failed to notice on the south gallery a very interesting exhibit,
consisting, as it did, of electrical apparatus made by boys. The
various devices there shown, comprising electro-magnets, telegraph keys
and sounders, resistance coils, etc., were turned out by boys following
the instructions given in the book with the above title, which is
unquestionably one of the most practical little works yet written that
treat of similar subjects, for with but a limited amount of mechanical
knowledge, and by closely following the instructions given, almost any
electrical device may be made at very small expense. That such a book
fills a long-felt want may be inferred from the number of inquiries
we are constantly receiving from persons desiring to make their own
induction coils and other apparatus."--_Electricity._
"At the electrical show in New York last May one of the most
interesting exhibits was that of simple electrical apparatus made by
the boys in one of the private schools in the city. This apparatus,
made by boys of thirteen to fifteen years of age, was from designs
by the author of this clever little book, and it was remarkable to
see what an ingenious use had been made of old tin tomato-cans,
cracker-boxes, bolts, screws, wire, and wood. With these simple
materials telegraph instruments, coils, buzzers, current detectors,
motors, switches, armatures, and an almost endless variety of apparatus
were made. In his book Mr. St. John has given directions in simple
language for making and using these devices, and has illustrated
these directions with admirable diagrams and cuts. The little volume
is unique, and will prove exceedingly helpful to those of our young
readers who are fortunate enough to possess themselves of a copy. For
schools where a course of elementary science is taught, no better
text-book in the first-steps in electricity is obtainable."--_The Great
Round World._
Exhibit of Experimental Electrical Apparatus AT THE ELECTRICAL
SHOW, MADISON SQUARE GARDEN, NEW YORK.
While only 40 pieces of simple apparatus were shown in this
exhibit, it gave visitors something of an idea of what young
boys can do if given proper designs.
[Illustration:
"HOW TWO BOYS MADE THEIR OWN ELECTRICAL APPARATUS"
Gives Proper Designs--Designs for over 150 Things.]
JUST PUBLISHED.
How Two Boys Made Their Own Electrical Apparatus.
Containing complete directions for making all kinds of simple
electrical apparatus for the study of elementary electricity.
By PROFESSOR THOMAS M. ST. JOHN, New York City.
The book measures 5 × 7-1/2 in., and is beautifully bound in
cloth. It contains 141 pages and 125 illustrations. Complete
directions are given for making 152 different pieces of
Apparatus for the practical use of students, teachers, and
others who wish to experiment.
PRICE, POST-PAID, $1.00.
The shocking coils, telegraph instruments, batteries, electromagnets,
motors, etc., etc., are so simple in construction that any boy of
average ability can make them; in fact, the illustrations have been
made directly from apparatus constructed by young boys.
The author has been working along this line for several years, and he
has been able, _with the help of boys_, to devise a complete line of
simple electrical apparatus.
_THE APPARATUS IS SIMPLE because the designs and methods of
construction have been worked out practically in the school-room,
absolutely no machine-work being required._
_THE APPARATUS IS PRACTICAL because it has been designed for real use
in the experimental study of elementary electricity._
_THE APPARATUS IS CHEAP because most of the parts can be made of old
tin cans and cracker boxes, bolts, screws, wires and wood._
Address, THOMAS M. ST. JOHN,
407 West 51st Street,
New York.
Fun With Magnetism.
BOOK AND COMPLETE OUTFIT FOR SIXTY-ONE EXPERIMENTS IN MAGNETISM....
[Illustration]
Children like to do experiments; and in this way, better than in any
other, _a practical knowledge of the elements of magnetism_ may be
obtained.
These experiments, although arranged to amuse boys and girls, have been
found to be very _useful in the class-room_ to supplement the ordinary
exercises given in text-books of science.
To secure the best _possible quality of apparatus_, the horseshoe
magnets were made at Sheffield, England, especially for these sets.
They are new and strong. Other parts of the apparatus have also been
selected and made with great care, to adapt them particularly to these
experiments.--_From the author's preface._
=CONTENTS.=--Experiments With Horseshoe Magnet.--Experiments With
Magnetized Needles.--Experiments With Needles, Corks, Wires, Nails,
etc.--Experiments With Bar Magnets.--Experiments With Floating
Magnets.--Miscellaneous Experiments.--Miscellaneous Illustrations
showing what very small children can do with the Apparatus.--Diagrams
showing how Magnetized Needles may be used by little children to make
hundreds of pretty designs upon paper.
=AMUSING EXPERIMENTS.=--Something for Nervous People to Try.--The
Jersey Mosquito.--The Stampede.--The Runaway.--The Dog-fight.--The
Whirligig.--The Naval Battle.--A String of Fish.--A Magnetic Gun.--A
Top Upsidedown.--A Magnetic Windmill.--A Compass Upsidedown.--The
Magnetic Acrobat.--The Busy Ant-hill.--The Magnetic Bridge.--The
Merry-go-Round.--The Tight-rope Walker.--A Magnetic Motor Using
Attractions and Repulsions.
_The Book and Complete Outfit will be sent, Post-paid, upon receipt of
35 Cents, by_
THOMAS M. ST. JOHN, 407 W. 51st St., New York.
A Few Off-Hand Statements
that have been made about "Fun With Magnetism" and "Fun With
Electricity" in letters of inquiry to the author. (These statements
were absolutely unsolicited.)
"My little boy has your 'Fun With Magnetism' and enjoys it so much that
if the 'Fun With Electricity' is ready I would like to have it for him.
Please let me know," etc.
"I have had much fun with 'Fun With Magnetism.'"
"My boy has 'Fun With Magnetism' and has enjoyed it very much and would
like the other. Will you," etc.
"Please let me know when 'Fun With Electricity' is upon the market, for
if it is as good as this, I shall certainly want it."
"I have just received 'Fun With Magnetism' and am delighted with it.
Please send me 12 sets," etc.
"I have 'Fun With Magnetism' and 'Fun With Electricity' and have
enjoyed them very much. Please send," etc.
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etc.
"'Fun With Electricity' is fine and I have had lots of fun with it.
Please send," etc.
"Having experimented with both of your apparatus 'Fun With Magnetism'
and 'Fun With Electricity,' and having found them both amusing and
instructive, I wish to ask," etc.
"I have purchased your outfits 'Fun With Electricity' and 'Fun With
Magnetism,' and though they are designed for amusement, I find them a
great help in my studies. Will you please," etc.
"I have one of your outfits of 'Fun With Electricity,' and I enjoy it
very much, some of the experiments being very astonishing. Will you
please," etc.
"I have enjoyed 'Fun With Magnetism' and 'Fun With Electricity' very
much."
"My little boy has your book 'Fun With Electricity,' which has given
him much amusement. He would like to have," etc.
"I am very much pleased with both outfits. I am very much in favor of
such things for boys; it keeps them occupied with something that is
both amusing and instructive. Send me," etc.
Fun With Electricity.
BOOK AND COMPLETE OUTFIT FOR SIXTY EXPERIMENTS IN ELECTRICITY....
[Illustration]
Enough of the principles of electricity are brought out to make the
book instructive as well as amusing. The experiments are systematically
arranged, and make a fascinating science course. No chemicals, no
danger.
The book is conversational and not at all "schooly," Harry and Ned
being two boys who perform the experiments and talk over the results as
they go along.
"The book reads like a story."--"An appropriate present for a
boy or girl."--"Intelligent parents will appreciate 'Fun With
Electricity.'"--"Very complete, because it contains both book and
apparatus."--"There is no end to the fun which a boy or girl can have
with this fascinating amusement."
=THERE IS FUN IN THESE EXPERIMENTS.=--Chain Lightning.--An Electric
Whirligig.--The Baby Thunderstorm.--A Race with Electricity.--An
Electric Frog Pond.--An Electric Ding-Dong.--The Magic
Finger.--Daddy Long-Legs.--Jumping Sally.--An Electric Kite.--Very
Shocking.--Condensed Lightning.--An Electric Fly-Trap.--The Merry
Pendulum.--An Electric Ferry-Boat.--A Funny Piece of Paper.--A Joke on
the Family Cat.--Electricity Plays Leap-Frog.--Lightning Goes Over a
Bridge.--Electricity Carries a Lantern.--And _=40 Others=_.
The _=OUTFIT=_ contains 20 different articles. The _=BOOK OF
INSTRUCTION=_ measures 5 × 7-1/2 inches, and has 38 illustrations, 55
pages, good paper and clear type.
_The Book and Complete Outfit will be sent, by mail or express, Charges
Prepaid, upon receipt of 65 Cents, by_
THOMAS M. ST. JOHN, 407 W. 51st St., New York.
Fun With Puzzles.
BOOK, KEY, AND COMPLETE OUTFIT FOR FOUR HUNDRED PUZZLES....
The BOOK measures 5 × 7-1/2 inches. It is well printed, nicely bound,
and contains 15 chapters, 80 pages, and 128 illustrations. The KEY is
illustrated. It is bound with the book, and contains the solution of
every puzzle. The COMPLETE OUTFIT is placed in a neat box with the
book. It consists of numbers, counters, figures, pictures, etc., for
doing the puzzles.
=CONTENTS=: _Chapter_ (1) Secret Writing. (2) Magic Triangles, Squares,
Rectangles, Hexagons, Crosses, Circles, etc. (3) Dropped Letter and
Dropped Word Puzzles. (4) Mixed Proverbs, Prose and Rhyme. (5) Word
Diamonds, Squares, Triangles, and Rhomboids. (6) Numerical Enigmas. (7)
Jumbled Writing and Magic Proverbs. (8) Dissected Puzzles. (9) Hidden
and Concealed Words. (10) Divided Cakes, Pies, Gardens, Farms, etc.
(11) Bicycle and Boat Puzzles. (12) Various Word and Letter Puzzles.
(13) Puzzles with Counters. (14) Combination Puzzles. (15) Mazes and
Labyrinths.
"Fun With Puzzles" is a book that every boy and girl should have. It
is amusing, instructive,--educational. It is just the thing to wake up
boys and girls and make them think. They like it, because it is real
fun. This sort of educational play should be given in every school-room
and in every home.
"Fun With Puzzles" will puzzle your friends, as well as yourself; it
contains some real brain-splitters. Over 300 new and original puzzles
are given, besides many that are hundreds of years old.
=Secret Writing.= Among the many things that "F. W. P." contains, is
the key to _secret writing_. It shows you a very simple way to write
letters to your friends, and it is simply impossible for others to read
what you have written, unless they know the secret. This, alone is a
valuable thing for any boy or girl who wants to have some fun.
_The Book, Key, and Complete Outfit will be sent, postpaid, upon
receipt of 35 cents, by_
THOMAS M. ST. JOHN, 407 West 51st St., New York City.
Fun With Soap-Bubbles.
BOOK AND COMPLETE OUTFIT FOR FANCY BUBBLES AND FILMS....
[Illustration]
=THE OUTFIT= contains everything necessary for thousands of beautiful
bubbles and films. All highly colored articles have been carefully
avoided, as cheap paints and dyes are positively dangerous in
children's mouths. The outfit contains the following articles:
One Book of Instructions, called "Fun With Soap-Bubbles," 1 Metal Base
for Bubble Stand, 1 Wooden Rod for Bubble Stand, 8 Large Wire Rings for
Bubble Stand, 1 Small Wire Ring, 3 Straws, 1 Package of Prepared Soap,
1 Bubble Pipe, 1 Water-proof Bubble Horn. The complete outfit is placed
in a neat box with the book. (Extra Horns, Soap, etc., furnished at
slight cost.)
=CONTENTS OF BOOK.=--Twenty-one Illustrations.--Introduction.--The
Colors of Soap-bubbles.--The Outfit.--Soap Mixture.--Useful
Hints.--Bubbles Blown With Pipes.--Bubbles Blown With Straws.--Bubbles
Blown With the Horn.--Floating Bubbles.--Baby Bubbles.--Smoke
Bubbles.--Bombshell Bubbles.--Dancing Bubbles.--Bubble
Games.--Supported Bubbles.--Bubble Cluster.--Suspended Bubbles.--Bubble
Lamp Chimney.--Bubble Lenses.--Bubble Basket.--Bubble Bellows.--To
Draw a Bubble Through a Ring.--Bubble Acorn.--Bubble Bottle.--A
Bubble Within a Bubble.--Another Way.--Bubble Shade.--Bubble
Hammock.--Wrestling Bubbles.--A Smoking Bubble.--Soap Films.--The
Tennis Racket Film.--Fish-net Film.--Pan-shaped Film.--Bow and Arrow
Film.--Bubble Dome.--Double Bubble Dome.--Pyramid Bubbles.--Turtle-back
Bubbles.--Soap-bubbles and Frictional Electricity.
"There is nothing more beautiful than the airy-fairy soap-bubble with
its everchanging colors."
_=THE BEST POSSIBLE AMUSEMENT FOR OLD AND YOUNG.=_
_The Book and Complete Outfit will be sent, POST-PAID, upon receipt of
35 cents, by_
THOMAS M. ST. JOHN, 407 West 51st St., New York City.
Things A Boy Should Know About Electricity.
(In Preparation.)
This book explains, in simple, straightforward language, many things
about electricity; things in which the American boy is intensely
interested; things he wants to know; things he should know.
It is free from technical language and rhetorical frills, but it tells
how things work, and why they work.
It is brimful of illustrations--the best that can be had--illustrations
that are taken directly from apparatus and machinery, and that show
what they are intended to show.
This book does not contain experiments, or tell how to make apparatus;
our other books do that. After explaining the simple principles of
electricity, it shows how these principles are used and combined to
make electricity do every-day work. The following are
_Some of the Things Electricity Can Do:_
It signals without wires.
It drills rock, coal, and teeth.
It cures diseases and kills criminals.
It protects, heats, and ventilates houses.
It photographs the bones of the human body.
It rings church bells and plays church organs.
It lights streets, cars, boats, mines, houses, etc.
It pumps water, cooks food, and fans you while eating.
It runs all sorts of machinery, elevators, cars, boats, and
wagons.
It sends messages with the telegraph, telephone, telautograph,
and search-light.
It cuts cloth, irons clothes, washes dishes, blackens boots,
welds metals, prints books, etc., etc.
_Everyone Should Know About Electricity._
=Things A Boy Should Know About Electricity= will interest _you_. We
shall be glad to send you complete information as soon as it is ready.
Send us your address now.
Dewey Flag Poles
=ARE LITTLE MODELS OF REAL FLAG POLES....=
[Illustration]
They are appropriate for any occasion, and suitable for any kind of
decoration. They should stand on tables, mantels, pianos, etc.; in
fact, there is no better ornament for general use.
"They should be in every home and in every school-room in the United
States."
"No toy fort complete without a Dewey Flag Pole."
"The children can fasten them on the windowsill and watch them flutter
by the hour."
"They hoist like big flags, at half-mast, etc."
"Invaluable for store-window decoration."
[Illustration]
PRICES
SMALL SIZE: height 18 inches, fitted with
United States or Cuban Silk Flag (4×6 in.)
post-paid, 30c.
LARGE SIZE: height 24 inches, fitted with
United States Silk Flag (7 × 10 in.), post-paid, 40c.
LARGE SIZE: fitted with Cuban or British Silk
Flag (8×12 in.), post-paid, 50c.
_DEWEY FLAG POLES are beautifully made of hard wood, and fitted with
best Silk Flags_.
GAMES.
Hustle=Ball.
A quick, sharp, decisive game that is thoroughly American.
Played by means of Magic Wands, and Polished Balls of Steel.
_=Needed:= "A quick eye and a nimble hand."_--_Shakespeare_.
_The Rule: Just keep cool--and hustle._
Four Games with One Outfit:
"Hustle Ball,"
"Leap-Frog,"
"Cross-Country Race,"
"Magnetic Potato-Race."
The game-board is new and original, as well as the methods of playing.
The game is put up in a strong box having a beautifully lithographed
cover, and measures 8 × 15-1/2 inches. With the game-board are
furnished, magic wands, polished steel balls, an "extra strength"
horseshoe magnet, and a complete set of illustrated rules and
directions for playing.
"Unlike all other games."
"Any one can play Hustle-Ball."
"Just the thing for progressive parties."
"Hustle-Ball games are intensely exciting."
"No waiting for some one to play."
"You win or lose a point in a few seconds."
"By handicapping the best players, all games are made equally
interesting and exciting."
"A game for Grandparents, as well as for Grandchildren."
A Brand-New Idea in Games.
[Illustration]
[Illustration]
'_A HUSTLE FROM THE WORD GO._'
_=This Exciting Game=_ will be sent, _=Charges Prepaid=_, by mail
or express, upon receipt of 65 Cents.
Address THOMAS M. ST. JOHN,
407 West 51st Street,
New York City.
JINGO
THE GREAT WAR GAME
Social Exciting Interesting Simple.
A Thorough War Game:--Infantry Against Infantry, Cavalry Against
Cavalry, Etc.
Jingo is really a great war contest between England and America. Upon
the game-board are 14 beautiful war scenes, each lithographed in 8
colors. American and English flags, coats of arms, cannon, torpedoes,
etc., aid in making this game artistic, handsome and attractive. The
following companies, ships, etc., are shown:--_American_, 12th U. S.
Infantry,--6th U. S. Cavalry,--2d U. S. Light Artillery,--U. S. Mortar
Battery,--U. S. Monitor "Miantonomoh,"--U. S. Ram "Katahdin,"--U.
S. Battleship "Indiana,"--U. S. Torpedo Boat "Cushing,"--U. S
Dynamite Cruiser "Vesuvius." _English_, 30th East Lancashire,--1st
Royal Dragoons,--Royal Horse Artillery,--Royal Artillery,--H. M.
S. "Thunderer,"--H. M. S. "Seagull,"--H. M. S. "Nile,"--H. M. S.
"Australia,"--H. M. S. "Dart."
The game board is over 16 inches square when opened. Jingo is made and
finished in a manner which makes it the most beautiful, artistic, and
practical game ever published.
"Just what every boy likes."
"A good idea well carried out."
"The Game-board is a work of art."
"Any child can play Jingo at once."
"It is the handsomest game on the market."
JINGO JUNIOR is the Greatest Game ever Invented for Little Folks.
It is played upon the Jingo board with the extra ammunition furnished.
These Two Great Games make a most complete and beautiful outfit for
home amusement.
JINGO AND JINGO JUNIOR.
Two Fascinating and Entirely Different Games, Played with One Outfit,
and Complete in One Box.
[Illustration]
_THIS HANDSOME OUTFIT_ for playing the _TWO GREAT WAR GAMES_
will be sent _CHARGES PREPAID_ upon receipt of _=$1.00=_.
Address THOMAS M. ST. JOHN,
407 West 51st Street,
New York City.
Transcriber's Notes
In the text version, Italic text is denoted by _underscores_ and bold
text by =equal signs=.
Obvious punctuation errors have been repaired.
The book contains some inconsistent hyphenation which has been left as
printed.
p. xi. (TOC) "constructiou" changed to "construction"
p. xiv. (TOC) "The Prodution of Motion" changed to "The Production of
Motion"
p. 27. para. 73. "thick permament magnets" changed to "thick permanent
magnets"
p. 99. para 253. "wabble" may be a typo for wobble but has been left on
the off chance that this could be what was intended.
p. 118. Fig 91. The final column has been scored through but appears to
read "CU to ZN"
p. 131. para. 324, 325. German-silver Wire, G-s W used here but
previously G S W used.
p. 164. para 395. "circuit in closed" changed to "circuit is closed"
p. 166. para 398. "core inside of the c l" changed to "core inside of
the coil" after checking original scans.
p. 169-170. It appears that a word has been omitted across the page
break. "The copper washer, C W, be used." has been changed to "The
copper washer, C W, should be used.". (Alternative words are possible!)
p. 211. No. 35. 5-16 in. changed to 5/16 in.
p. 213. No. 92, 93. 5-16 in. changed to 5/16 in.
p. 214. No. 96. and No. 97. 5-16 in. changed to 5/16 in.
p. 216. Entry for Coulomb moved from end of "C" to above Current.