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LITTLE BLUE BOOK NO. 133
Edited by E. Haldeman-Julius
Principles of
Electricity
Maynard Shipley
HALDEMAN-JULIUS COMPANY
GIRARD, KANSAS
Copyright, 1925,
Haldeman-Julius Company.
PRINTED IN THE UNITED STATES OF AMERICA
PRINCIPLES OF ELECTRICITY
CONTENTS
Chapter Page
1. “What Is Electricity?” 5
2. Magnetic Phenomena 13
3. Pioneers in Electromagnetic Theory 19
4. Theories of Electricity 30
5. Modern Magnetic Theory 41
6. Proofs that Electrons Are Atoms of Electricity 44
7. The Discovery of Wireless Telegraphy 55
PRINCIPLES OF ELECTRICITY
CHAPTER 1
“WHAT IS ELECTRICITY?”
Many persons who have devoted no time to the study of physics wonder
what the force is that drives the street-car along—turning its wheels,
while at the same time furnishing incandescent lamps (light) for the
passengers. They have been told, of course, that the “power” used is
“electricity”, generated by dynamos “at the power-house”, and conveyed
to the rapidly moving car by the overhead wire.
“Electricity: yes, but what is electricity?” This is a natural and
perfectly legitimate question for a layman to ask.
Scientists and philosophers are asking the same question. But they
understand quite well that it is like asking: “What is matter?” Very
probably the average inquirer does not ask the question, “What is
electricity?” in the same spirit. We can answer one question no better
than the other, if the ultimate nature of either matter or electricity
is what the inquirer has in mind.
For matter, in the last analysis, is electricity. Yet the same person
who might ask: “What is electricity?” would not think of asking: “What
is matter?” He thinks he knows what matter is—his common sense tells
him that _matter is what it appears to be_. “Matter’s matter, and
there’s an end of it.”
And just so the physicist insists upon his common-sense right to
reply: “Electricity is electricity.” It is what it appears to him to
be. And it appears to be a form of _energy_, or a _mode of
motion_.
Thales, the reputed founder of Greek science and philosophy, would
call electricity “the soul of the universe”, because it “endows all
things with motion”. This “soul”, interpenetrating all matter—if not
constituting it—is by nature always moving—it is self-moving; motion
is part of its very essence. In the lodestone, said Thales, “it moves
iron.”[1]
As has been said so many times before, Thales was the first to call
attention to the fact that amber (fossilized resin), when rubbed
with wool or fur, possesses the curious property of attracting small
particles, such as straw, pith, lint, dried leaves, etc.;—though there
is no reason to suppose that he was the discoverer of this phenomenon.
He called the amber _elektron_; and today we call the indivisible
corpuscles, or natural unit charges of negative electricity,
_electrons_—the true _atoms_ of electricity.
But hard rubber, or sealing-wax, is just as “mysterious” as the
lodestone (magnetite—natural magnetic iron). Rub the sealing-wax with
fur, and it will exhibit all the peculiar properties of the lodestone.
Rub glass with silk, and it, too, becomes a lodestone in effect. The
ancient Greek philosophers could not explain these phenomena in precise
terms.
Empedocles (born between 500 and 480 B. C.) accounted for the
attraction of iron to the magnet on the hypothesis that “emanations”
or “effluences” from the magnet penetrate into the “symmetrical pores”
of the iron, drawing the iron itself and holding it fast. The concept
“electricity” was unknown to the Greeks. But it is possible that
Empedocles had in mind some such “effluence” or “emanation” as the
“fluid” electricity of Benjamin Franklin (1706-1790) and his successors.
The soul-force (“moving power”) of Thales—always moving and causing
movement—and the “effluences” of Empedocles have become the “field
of force” of Faraday, Sir J. J. Thomson, and Sir Oliver Lodge. The
self-moving “soul” of nature, manifest in the lodestone, or acting
on the lodestone, or on the particles said to be “attracted” by the
lodestone, is but a synonym for the lines of force of the magnetic
field of modern physics. Thales and Empedocles spoke in the language
(terminology) of their day and age. The “emanations” of Empedocles are
the “corpuscles” of Thomson—a body becoming positively electrified
by “losing some of its corpuscles”, and hence capable of drawing
negatively charged particles to itself.
Electricity and magnetism are related but not identical. A moving
magnet can induce an electric current in a wire, and an electric
current can produce magnetism in iron. The construction of telegraph
and telephone instruments depends on the fact that an electric current
can produce magnetism and that magnetism can produce an electric
current.
We know _effects_ which we call “electricity”, just as we know the
phenomena associated with living protoplasm without knowing what “life”
is. It may be that “life” and “electricity”, as well as “electricity”
and “magnetism”, are all different aspects of the same thing.
Today we say, in the words of Dr. Charles P. Steinmetz (“Relativity and
Space”, Pages 18-19):—
“The space surrounding a magnet is a magnetic field. If we electrify a
piece of sealing-wax by rubbing it, it surrounds itself by a dielectric
or electrostatic field, and bodies susceptible to electrostatic
forces—such as light pieces of paper—are attracted. The earth is
surrounded by a gravitational field, the lines of gravitational force
issuing radially from the earth. If a stone falls to the earth, it is
due to the stone’s being in the gravitational field of the earth and
being acted upon by it.”
Again:—“Suppose we have a permanent bar magnet and bring a piece of
iron near it. It is attracted, or moved; that is, a force is exerted on
it. We bring a piece of copper near the magnet, and nothing happens. We
say that the space surrounding the magnet is a _magnetic field_.
A _field_, or _field of force_, we define as ‘a condition
in space exerting a force on a body susceptible to this field’. Thus,
a piece of iron being magnetizable—that is, susceptible to a magnetic
field—will be acted upon; a piece of copper, not being magnetizable,
shows no action.... To produce a field of force requires energy, and
this energy is stored in the space we call the field. Thus we can go
further and define the field as ‘_a condition of energy storage in
space exerting a force on a body susceptible to this energy_’.”
Thales said that the “divine moving power”, the soul of nature, under
certain conditions “moves iron”, through the mysterious properties
of the lodestone. Modern science, borrowing from Aristotle the term
_energia_, substitutes for “soul of nature” the single word
_energy_. Aristotle declared that “not capacity, but energy ...
is the first principle anterior to and superior to anything else”
(_Metaphysics_ xii, 7: cf. also _Physics_ ii, 9, 6).
Modern science describes in more precise phrases what _occurs_
when a body susceptible to the influence of the magnet is brought into
proximity to a lodestone (magnetite). It gives us a picture of “lines
of force” (energy) in a defined “field”. But it tells us no more about
what energy _is_ than Thales tells us what his “moving power” is.
Dr. Steinmetz tells us that “energy is the only real existing entity,
the primary conception, which exists for us because our senses respond
to it” (_Op. cit._, Page 23). For Thales the universal “moving
power” of nature operates _on_ or _in_ all matter; for the
physicist of today the moving power (energy) is matter—man’s perception
of matter being the response of his senses to the vibrations of energy.
“All sense perceptions are exclusively energy effects,” and “energy is
the only real existing entity.”
Thales may or may not have considered the cosmos as “matter”
_and_ “soul” or “moving power”. In any event the pre-Socratic
Ionian philosophers recognized no distinction between matter and soul
in our modern sense. The moving power of nature (soul) was as much a
material substance as gross matter itself, only more rarefied, more
elusive. It was equivalent to the “energy”—electricity—of modern
science.
Here we have, then, the answer to the question: “What is electricity?”
It is _energy_—“the only real existing entity, the primary
conception, which exists for us because our senses respond to it.” “All
sense perceptions are exclusively energy effects.” This is the answer
to the question: “What are the Hertzian waves, used in ‘wireless’?” It
is the answer also to the question: “What is light?” as well as “What
is electricity?” By carrying the explanation of the beam of light
and the electromagnetic wave (like that of the radio communication
station or that surrounding a power transmission line) back to the
_energy_ field (or, less accurately, the field of force), we have
carried it back, as Dr. Steinmetz well declared, as far as possible,
“to the fundamental or primary conceptions of the human mind, the
perceptions of the senses.”
All that we know of the world is derived from the _perceptions of our
senses_, which are for us the only _real facts_, all things
else being conclusions from them; and “all sense perceptions are
exclusively _energy_ effects.” Electricity is an energy effect,
perceived by our senses. No other definition or explanation can or need
be given, since _energy is the primary conception_. And this
explains also what matter is, since _energy_ and _matter_ are
interchangeable—or equivalent—terms. What we call electricity is one
of the _effects of energy_ on our senses. In itself, it _is_
energy, the stuff that matter is made of; at once the “moving power”
and the thing moved.
Everything has been said that can be said now as to what electricity
_is_: our concern in the remainder of this volume will be to
discover what electricity _does_ and how it acts.
* * * * *
The reader of this little book who may be more or less familiar
with larger volumes dealing with electricity, energy, electrons,
electromagnetic waves or oscillations, magnetic and dielectric fields
(usually combined), light-waves, etc., will notice that no mention
has been made of the classical ether hypothesis, the universal
_plenum_ in which energy is said to be stored, and in which
transverse waves of light are said to occur, ether atoms or vibrations
moving at right angles (perpendicularly) to the light-beam.
Now, transverse waves can exist only in rigid (solid) bodies. The
universal ether of space, referred to in the text-books, must—for
reasons which I need not discuss here—be a solid body of a rigidity
much greater than that of steel, while at the same time possessing
a very great elasticity so that bodies (such as the planets) moving
through it meet with no resistance, no friction. The electron theory of
Lorentz, Larmor, Thomson, Lodge and others is based upon the assumption
that such a _plenum_, or medium, is a real substance. As a matter
of fact, it is not known that any such medium (or ether) does exist,
and it is now recognized that while light is a _wave_, a periodic
phenomenon, like an alternating current, it is not necessarily a
wave _motion_ of something or in something, any more than it is
necessary to assume the alternating current or voltage wave to be a
motion of matter.
Electrical engineers make no assumption regarding the existence of an
ether filling all space and interpenetrating all matter—have no need
for an ether as the hypothetical carrier of the electric wave. And just
so the physicist of today has no real need for the classical assumption
that the light-wave is a wave motion of or in something of great
rigidity yet highly elastic and frictionless, filling all space. Light
is now known to be a high-frequency electromagnetic wave, and cannot
logically be considered as a wave motion of a hypothetical ether. “The
ether thus vanishes, following the phlogistin and other antiquated
conceptions.”[2] As Prof. A. S. Eddington remarks in his “Report on
the Relativity Theory of Gravitation” (1920), “Light does not cause
electromagnetic oscillations; it _is_ the oscillations.”
We know nothing whatever about the so-called ether of space; but we can
formulate very clearly “The Principles of Electricity” without the aid
of that hypothesis.[3]
FOOTNOTES:
[1] If a light piece of iron is placed near a magnet, it moves to the
magnet and clings to it; but if the magnet is the lighter of the two
bodies, it moves toward the piece of iron.
[2] Steinmetz, Dr. Charles P., “Four Lectures on Relativity and Space,”
Pages 21-22, London and New York, 1923. See Lecture II, “Conclusions
from the Relativity Theory,” Pages 12-45. See also, Campbell, Dr.
Norman R., “Modern Electrical Theory. Supplementary Chapters:
Relativity,” Cambridge University Press, 1923.