_BY THE SAME AUTHOR._
=FUN WITH MAGNETISM.= A book and complete outfit for _Sixty-One
Experiments_.
=FUN WITH ELECTRICITY.= A book and complete outfit for _Sixty
Experiments_.
=FUN WITH PUZZLES.= A book and complete outfit for _Four
Hundred Puzzles_.
=FUN WITH SOAP-BUBBLES.= A book and complete outfit for _Fancy
Bubbles and Films_.
=HUSTLE-BALL.= An American game. Played by means of magic wands
and polished balls of steel.
=JINGO.= The great war game, including =JINGO JUNIOR=.
=HOW TWO BOYS MADE THEIR OWN ELECTRICAL APPARATUS.= A book
containing complete directions for making all kinds of simple
apparatus for the study of elementary electricity.
=THE STUDY OF ELEMENTARY ELECTRICITY AND MAGNETISM BY
EXPERIMENT.= This book is designed as a text-book for amateurs,
students, and others who wish to take up a systematic course of
simple experiments at home or in school.
_IN PREPARATION._
=THINGS A BOY SHOULD KNOW ABOUT ELECTRICITY.= 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.
_Ask Your Toy Dealer, Stationer, or Bookseller for
our Books, Games, Puzzles, Educational
Amusements, Etc._
Thomas M. St. John, 407 West 51st St., New York.
The Study of Elementary Electricity
and Magnetism by Experiment
Containing
TWO HUNDRED EXPERIMENTS
PERFORMED WITH
SIMPLE, HOME-MADE APPARATUS
BY
THOMAS M. ST. JOHN, Met. E.
Author of "Fun With Magnetism," "Fun With Electricity," "How
Two Boys Made Their Own Electrical Apparatus," Etc.
[Illustration: Logo]
NEW YORK
THOMAS M. ST. JOHN
407 West 51st Street
1900
Copyright, 1900,
By THOMAS M. ST. JOHN.
To the Student.
This book is designed as a text-book for amateurs, students, and others
who wish to take up a systematic course of elementary electrical
experiments at home or in school.
The student is advised to begin at the beginning, to perform the
experiments in the order given, and to understand each step before
proceeding. Certain principles and explanations necessarily precede the
practical and perhaps more interesting applications of those principles.
In selecting the apparatus for the experiments in this book, the author
has kept constantly in mind the fact that the average student will not
buy the expensive pieces usually described in text-books.
The two hundred experiments given can be performed with simple,
inexpensive apparatus; in fact, the student should make at least a part
of his own apparatus.
For the benefit of those who wish to make their own apparatus, the
author has given, throughout the work, explanations that will aid
in the construction of certain pieces especially adapted to these
experiments. For those who have the author's "How Two Boys Made Their
Own Electrical Apparatus," constant references have been made to it
as the "Apparatus Book," as this contains full details for making
almost all kinds of simple apparatus needed in "The Study of Elementary
Electricity and Magnetism by Experiment."
THOMAS M. ST. JOHN.
_New York, April, 1900._
The Study of Elementary Electricity and
Magnetism by Experiment
PART I--MAGNETISM
PART II--STATIC ELECTRICITY
PART III--CURRENT ELECTRICITY
The Study of Elementary Electricity and Magnetism by Experiment.
TABLE OF CONTENTS.
PART I.--MAGNETISM.
PAGE.
CHAPTER I. =Iron and Steel= 3
Introduction.--Kinds of iron and steel.--Exp. 1, To
study steel.--Discussion.--Exp. 2, To find whether a
piece of hard steel can be made softer.--Annealing.--Exp.
3, To find whether a piece of annealed steel can be
hardened.--Hardening; Tempering.--Exp. 4, To test the
hardening properties of soft iron.--Discussion.
CHAPTER II. =Magnets= 7
Kinds of magnets.--Exp. 5, To study the horseshoe magnet.--Poles;
Equator.--Exp. 6, To ascertain the nature of substances attracted
by a magnet.--Magnetic Bodies; Diamagnetic Bodies.--Practical
Uses of Magnets.--Exp. 7, To study the action of magnetism
through various substances.--Magnetic Transparency; Magnetic
Screens.--Exp. 8, To find whether a magnet can give magnetism
to a piece of steel.--Discussion; Bar Magnets.--Exp. 9, To make
small magnets.--Exp. 10, To find whether a freely-swinging bar
magnet tends to point in any particular direction.--North-seeking
Poles; South-seeking Poles; Pointing Power.--The Magnetic
Needle; The Compass.--Exp. 11, To study the action of magnets
upon each other.--Exp. 12, To study the action of a magnet upon
soft iron.--Laws of Attraction and Repulsion.--Exp. 13, To
learn how to produce a desired pole at a given end of a piece
of steel.--Rule for Poles.--Our Compass.--Review; Magnetic
Problems.--Exp. 14, To find whether the poles of a magnet
can be reversed.--Discussion; Reversal of Poles.--Exp. 15,
To find whether we can make a magnet with two N poles.--Exp.
16, To study the bar magnet with two N poles.--Discussion;
Consequent Poles.--Exp. 17, To study consequent poles. Exp.
18, To study the theory of magnetism.--Theory of Magnetism;
Magnetic Saturation.--Exp. 19, To find whether soft iron
will permanently retain magnetism.--Retentivity or Coercive
Force; Residual Magnetism.--Exp. 20, To test the retentivity
of soft steel.--Discussion.--Exp. 21, To test the retentivity
of hard steel.--Exp. 22, To test the effect of heat upon a
magnet.--Discussion.--Exp. 23, To test the effect of breaking a
magnet.--Discussion.
CHAPTER III. =Induced Magnetism= 20
Exp. 24, To find whether we can magnetize a piece of iron
without touching it with a magnet.--Temporary Magnetism;
Induced Magnetism.--Exp. 25, To find whether a piece of steel
can be permanently magnetized by induction.--Exp. 26, To
study the inductive action of a magnet upon a piece of soft
iron.--Polarization; Pole Pieces.--Exps. 27-30, To study pole
pieces.
CHAPTER IV. =The Magnetic Field= 23
Exp. 31, To study the space around the magnet, in
which pieces of iron become temporary magnets by
induction.--Discussion; The Magnetic Field.--Exp. 32, To
study the magnetic field of a bar magnet.--Magnetic Figures;
Lines of Magnetic Force.--Exps. 33-37, To study
the magnetic fields of various combinations of bar magnets.--Exps.
38-39, To study the lifting power of combinations
of bar magnets.--Discussion; Compound Magnets.--Exps.
40-42, To study the magnetic field of the
horseshoe magnet.--Discussion; Resistance to Lines of
Force.--Exp. 43, To show that lines of force are on all
sides of a magnet.--Discussion.--Exp. 44, To study a
horseshoe magnet with movable poles.--Discussion; Advantages
of Horseshoe Magnets.
CHAPTER V. =Terrestrial Magnetism= 31
The Magnetism of the Earth.--Declination.--Exp. 45, To study
the lines of force above and below a bar magnet placed
horizontally.--The Dip or Inclination of the Magnetic
Needle.--Exp. 46, To study the dip or inclination of the magnetic
needle due to the action of the earth.--Discussion; Balancing
Magnetic Needles.--Exps. 47-48, To study the inductive influence
of the earth.--Discussion.--Natural Magnets.--Exp. 49, To test
the effect of twisting a wire held north and south in the earth's
magnetic field.--Exp. 50, To test for magnetism in bars of iron,
tools, etc.
PART II.--STATIC ELECTRICITY.
CHAPTER VI. =Electrification= 39
Some Varieties of Electricity.--Exp. 51-52, To study
electrification by friction.--Discussion.--Electrified and
Neutral bodies.--Force; Resistance; Work; Potential Energy;
Electrification.--Heat and Electrification.--Exps. 53-54, To
study electrical attraction.--Discussion.--Exp. 55, To study
mutual attractions.--Mutual Attractions.--Exps. 56-58, To study
electrical repulsions.--The Carbon Electroscope.--Discussion of
Experiments 56, 57, 58.--Exp. 59, To study the electrification
of glass.--Questions.--Exp. 60, To compare the electrification
produced by ebonite and flannel with that produced by glass and
silk.--Discussion.--Laws.
CHAPTER VII. =Insulators and Conductors= 47
Exps. 61-63, To study insulators.--Conductors.--Exp.
64, To study conduction.--Discussion.--Exp. 65,
To study conduction.--Telegraph line using static
electricity.--Discussion.--Relation between conductors and
insulators.--Electrics and Non-electrics.--Exp. 66, To study the
effect of moisture upon an insulator.--Discussion.--Exp. 67, To
test the effects of moisture upon bodies to be electrified.
CHAPTER VIII. =Charging and Discharging Conductors= 52
The Electrophorus.--Exp. 68, To learn how to use the
electrophorus.--Exp. 69, To study "charging by conduction."--Exp.
70, To study potential; Electromotive force.--Pressure;
Potential; Electromotive force; Current, Spark.--Theories about
Electrifications.--Exp. 71, To study some methods of discharging
an electrified body.--Disruptive, Conductive and Convective
Discharges.--Exp. 72, To study intermittent or step-by-step
discharges.--Discussion.--Exp. 73, To ascertain the location of
the charge upon an electrified conductor.--Discussion.--Hollow
and Solid Conductors.--Exp. 74, To study the effect of points
upon a charged conductor.--Electric Density.--Electric Wind.
CHAPTER IX. =Induced Electrification= 60
Electric Fields; Lines of Force.--Exp. 75, To study
electric induction.--Electric Polarization; Theory of
Induction.--Exp. 76, To learn how to charge a body by
induction.--Free and Bound Electrifications.--Exp. 77, To
show that a neutral body is polarized before it is attracted
by a charged one.--Polarization Precedes Attraction.--Exp.
78, To find whether electric induction will act through an
insulator.--Dielectrics.--Exp. 79, To find whether a polarized
conductor can act inductively upon another conductor.--Successive
Induction.--Inductive Capacity.--Exp. 80, To study the action of
the electrophorus.--Discussion.--Details of action.--Exp. 81,
To see, hear, and feel the results of inductive influence and
polarization.--Discussion.
CHAPTER X. =Condensation of Electrification= 68
Exp. 82, To find whether a large surface will hold more
electrification than a small one.--Electrical Capacity.--Exp.
83, To find whether the capacity of a given conductor can
be increased without increasing its size.--Condensation;
Condensers.--The Leyden Jar.--Fulminating Panes.--Induction
Coil Condensers.--Submarine Cables.--Exp. 84, To study the
condensation of electrification.--Discussion.--Exp. 85, To study
the action of the condenser.--Discussion.--Exp. 86, To study the
effect of electrical discharges upon the human body.--Shocks;
Dischargers.--Exps. 87-88, To show the strong attraction between
opposite electrifications in the condenser.--Discussion.--Exp.
89, To show how the condenser may be slowly discharged.--The
Electric Chime.--Exp. 90, To ascertain the location of a charge
in a condenser.--Discussion.--Exp. 91, To find whether any
electrification remains in the condenser after it has once been
discharged.--Residual Charge.--Exp. 92, To study successive
condensation; the chime cascade.--Discussion.
CHAPTER XI. =Electroscopes= 77
Electroscopes.--Our leaf electroscope.--Exp. 93, To study the
leaf electroscope; charging by conduction.--Discussion.--Exp.
95, To learn some uses of the electroscope.--Discussion.--The
Proof-plane.
CHAPTER XII. =Miscellaneous Experiments= 81
Exp. 96, To show that friction always produces two kinds of
electrification.--Discussion.--Exp. 97, To show "successive
sparks."--Exp. 98, To show to the eye the strong attraction
between a charged and a neutral body.--Exp. 99, To feel the
strong attraction between a charged and a neutral body.--Exp.
100, The human body a frictional electric machine.--Static
Electric Machines.
CHAPTER XIII. =Atmospheric Electricity= 84
Atmospheric Electricity.--Lightning.--Thunder.--Lightning
Rods.--Causes of Atmospheric Electricity.--St. Elmo's
Fire.--Aurora Borealis.
PART III.--CURRENT ELECTRICITY.