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_NATURE'S MIRACLES, VOL. III._
Electricity
and Magnetism
BY
ELISHA GRAY, PH.D., LL.D.
WILLIAM BRIGGS
29-33 Richmond St. West, Toronto
C. W. COATES, Montreal, Que.
S. F. HUESTIS, Halifax, N.S.
CONTENTS.
CHAPTER PAGE
INTRODUCTION v
I. THE AUTHOR'S DESIGN 1
II. HISTORY OF ELECTRICAL SCIENCE 6
III. HISTORY OF MAGNETISM 20
IV. THEORY AND NATURE OF MAGNETISM 25
V. THEORY OF ELECTRICITY 39
VI. ELECTRICAL CURRENTS 49
VII. ELECTRIC GENERATORS 62
VIII. ATMOSPHERIC ELECTRICITY 77
IX. ELECTRICAL MEASUREMENT 83
X. THE ELECTRIC TELEGRAPH 88
XI. RECEIVING MESSAGES 103
XII. MISCELLANEOUS METHODS 108
XIII. MULTIPLE TRANSMISSION 114
XIV. WAY DUPLEX SYSTEM 129
XV. THE TELEPHONE 134
XVI. HOW THE TELEPHONE TALKS 145
XVII. SUBMARINE TELEGRAPHY 154
XVIII. SHORT-LINE TELEGRAPHS 159
XIX. THE TELAUTOGRAPH 165
XX. SOME CURIOSITIES 171
XXI. WIRELESS TELEGRAPHY 176
XXII. NIAGARA FALLS POWER--INTRODUCTION 186
XXIII. NIAGARA FALLS POWER--APPLIANCES 190
XXIV. NIAGARA FALLS POWER--APPLIANCES 199
XXV. ELECTRICAL PRODUCTS--CARBORUNDUM 209
XXVI. ELECTRICAL PRODUCTS--BLEACHING-POWDER 218
XXVII. ELECTRICAL PRODUCTS--ALUMINUM 223
XXVIII. ELECTRICAL PRODUCTS--CALCIUM CARBIDE 228
XXIX. THE NEW ERA 234
INTRODUCTION.
For the benefit of the readers of Vol. III, who have not read the
general Introduction found in Vol. I, a word as to the scope and object
of this volume will not be amiss.
It will be plain to any one on seeing the size of the little book that
it cannot be an exhaustive treatise on a subject so large as that of
Electricity. This volume, like the others, is intended for popular
reading, and technical terms are avoided as far as possible, or when
used clearly explained. The subject is treated historically,
theoretically, and practically.
As the author has lived through the period during which the science of
Electricity has had most of its growth, he naturally and necessarily
deals somewhat in reminiscence. All he hopes to do is to plant a few
seed-thoughts in the minds of his readers that will awaken an interest
in the study of natural science; and especially in its most fascinating
branch--Electricity.
If Vol. I is at hand, please read the Introduction. It will bring you
into closer sympathy with the author and his mode of treatment.
Again, if the reader is especially interested in the theory of
Electricity it will help him very much if he first reads Vols. I and II,
as a preparation for a better understanding of Vol. III. All the natural
sciences are so closely related that it is difficult to get a clear
insight into any one of them without at least a general idea of all the
others.
NATURE'S MIRACLES.
ELECTRICITY AND MAGNETISM.
CHAPTER I.
THE AUTHOR'S DESIGN.
The writer has spent much of his time for thirty-five years in the study
of electricity and in inventing appliances for purposes of transmitting
intelligence electrically between distant points, and is perhaps more
familiar with the phenomena of electricity than with those of any other
branch of physics; yet he finds it still the most difficult of all the
natural sciences to explain. To give any satisfactory theory as to its
place with and relation to other forms of energy is a perplexing
problem.
It is said that Lord Kelvin lately made the statement that no advance
had been made in explaining the real nature of electricity for fifty
years. While this statement--if he really made it--is rather broad, it
must be acknowledged that all the theories so far advanced are little
better than guesses. But there is value in guessing, for one man's guess
may lead to another that is better, and, as it is rarely the case that
each one does not give us a little different view of the matter, it may
be that out of the multiplicity of guesses there may some time be a
suggestion given to some investigator that will solve the problem, or at
least carry the theme farther back and establish its true relationship
to the other forms of energy. I cannot but think that there is yet a
simple statement to be made of Energy in its relation to Matter that
will establish a closer relationship between the different branches of
physical science. And this, most likely, will be brought about by a
better understanding of the nature of the interstellar substance called
Ether, and its relation to all forms and conditions of sensible matter
and energy.
In the talks that will follow it will be the endeavor of the writer to
give such a simple and popular exposition of the phenomena and
applications of electricity, in a general way only, that the popular
reader may get, at least, an elementary understanding of the subject so
far as it is known. As we have said, the descriptions will have to be
elementary, for nothing else can be done without such elaborate
technical drawings and specifications as would be impossible in our
limited space, and would not be clear to the ordinary reader who knows
nothing of the science.
Thousands who are employed in various ways with enterprises, the
foundations of which are electrical, know nothing of electricity as a
science. A friend of mine, who is a professor of physics in one of our
colleges, was traveling a few years ago, and in his wanderings he came
across some sort of a factory where an electric motor was employed.
Being on the alert for information, he stepped in and introduced himself
to the engineer, and began asking him questions about the electric motor
of which he had charge. The professor could talk ohm, amperes, and volts
smoothly, and he "fired" some of these electrotechnical names at the
engineer. The engineer looked at him blankly and said: "You can't prove
it by me. I don't know what you're talking about. All I know is to turn
on the juice and let her buzz." How much "juice" is wasted in this
cut-and-dry world of ours and how much could be saved if only all were
even fairly intelligent regarding the laws of nature! A great deal of
the business of this world is run on the "let her buzz" theory, and the
public pays for the waste. It will continue to be so until a higher
order of intelligence is more generally diffused among the people. A
fountain can rise no higher than its source. A business will never
exceed the intelligence that is put into it, nor will a government ever
be greater than its people.
Let us begin the subject of electricity by going somewhat into its past
history. It is always well to know the history of any subject we are
studying, for we often profit as much by the mistakes of others as by
their successes. I shall also give the theories advanced by different
investigators, and if I should have any thoughts of my own on the
subject I shall be free to give them, for I have just as good a right to
make a guess as any one. It must be confessed, however, that the older I
grow the less I feel that I know about the subject of electricity, or
anything else, in comparison with what I see there is yet to be known. I
once met a young man who had just graduated from college, and in his
conversation he stated that he had taken a course in electricity. I
asked him how long he had studied the subject. He said "three months." I
asked him if he understood it--and he said that he did. I told him that
he was the man that the world was looking for; that I had studied it for
thirty years and did not understand it yet.
"A little learning is a dangerous thing"--for it puffs us up, and we
feel that we know it all and have the world in our grasp; but after we
have tried our "little learning" on the world for a while and have
received the many hard knocks that are sure to come, we are sooner or
later brought up in front of the mirror of experience, and we "see
ourselves as others see us," and are not satisfied with the view.
Whatever the theories may be regarding electricity, and however
unsatisfactory they may be, there are certain well-defined facts and
phenomena that are of the greatest importance to the world. These we may
understand: and to this end let us especially direct our efforts.