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THE AUTOBIOGRAPHY OF AN ELECTRON


[Illustration: A WELL-KNOWN PHENOMENON PRODUCED BY ELECTRONS

_Photo_

_The Fleet Agency_

A sudden discharge of electrons from cloud to cloud, or from cloud to
the earth, constitutes what we call "lightning."]


THE AUTOBIOGRAPHY OF AN ELECTRON.

Wherein the Scientific Ideas of the Present
Time Are Explained in an Interesting
and Novel Fashion

by

CHARLES R. GIBSON, F.R.S.E.

Author of "Scientific Ideas of To-Day," "Electricity of To-Day"
"The Romance of Modern Electricity," _&c. &c._

Illustrated







Philadelphia
J. B. Lippincott Company
London: Seeley & Co. Limited
1911




PREFACE


Although text-books of science may appear to the general reader to be
"very dry" material, there is no doubt that, when scientific facts and
theories are put into everyday language, the general reader is genuinely
interested. The reception accorded to the present author's _Scientific
Ideas of To-day_ bears out this fact. While that volume explains, in
non-technical language, the latest scientific theories, it aims at
giving a fairly full account, which, of course, necessitates going into
a great deal of detail. That the book has been appreciated by very
varied classes of readers is evident from the large numbers of
appreciative letters received from different quarters. But the author
believes that if the story of modern science were told in a still more
popular style, it would serve a further useful purpose. For there are
readers who do not care to go into details, and yet would like to take
an intelligent interest in the scientific progress of the present day.
Some of those readers do not wish to trouble about names and dates,
while the mere mention of rates of vibration and such-like is a worry to
them. They wish a book which they may read with the same ease as an
interesting novel. Hence the form of the present volume.

       *       *       *       *       *

The author is indebted to Professor James Muir, M.A., D.Sc., of the
Glasgow and West of Scotland Technical College, and to H. Stanley Allen,
M.A., D.Sc., Senior Lecturer in Physics at King's College, University of
London, for very kindly reading the proof-sheets. The author is indebted
further to Professor Muir in connection with some of the illustrations,
and for others to Dixon and Corbitt and R. S. Newall, Ltd., Glasgow;
Siemens Schuckert Werke, Berlin.




CONTENTS


                                                                    PAGE

CHAPTER I

WHAT THE STORY IS ABOUT

The Scribe introduces the Electron to the reader. He has something
    to say also about the mysterious aether which pervades all
    space. He emphasises the fact that the electron is a real
    existing thing                                                    21

CHAPTER II

THE ELECTRON'S PREFACE

The Electron explains the reason why it has written its
    autobiography                                                     29

CHAPTER III

THE NEW ARRIVAL

The Electron points out who the new arrival is really. It relates
    an amusing experience. It tells how man disturbed electrons
    before he discovered their existence. An ancient experiment,
    and what the wise men of the East thought about it. How
    electrons are responsible for the electrification of any
    object. Handled by a new experimenter, they surprise man. Man
    becomes of special interest to the electrons                      32

CHAPTER IV

SOME GOOD SPORT

The Electron explains how man succeeded in crowding them together,
    with some rather exciting results from the overcrowding. One
    historical incident. Man's fear of the consequences. How a
    party of electrons wrecked a church steeple. An unfortunate
    accident                                                          42

CHAPTER V

MY EARLIEST RECOLLECTIONS

The Electron's story begins at a very far distant period, before
    this world had taken shape. The Electron was present when the
    atoms of matter were being formed. The birth of the moon.
    Something still to be discovered. The moulding of the planet.
    Boiling oceans. The electrons took an active part in making
    sea-water salt. The Electron explains why it has been chosen to
    write the story of itself and its fellows                         52

CHAPTER VI

MAN PAYS US SOME ATTENTION

The electrons are encouraged by one of the experiments made by man.
    They hope it may lead to their discovery, so that their
    services may be recognised. The Electron's experience in a
    vacuum tube. A disappointment and a revival of hope. A great
    declaration by one individual man. The Electron misjudges man.
    Mention of a great discovery. The christening of the electrons    60

CHAPTER VII

A STEADY MARCH

The Electron explains how they produce the electric current. How
    man discovered means of making the electrons march. A simple
    explanation of how a complete electric circuit is always
    necessary. How an "earth circuit" works. How the marching
    electrons can do work                                             68

CHAPTER VIII

A USEFUL DANCE

A perpetual dance. A responsible position. How the safety of the
    mariner depends upon the electrons' dance. How electrons
    produce a magnet. A convenient kind of magnet, which gains and
    loses its attractive power when desired. How a permanent magnet
    is made. The great service of electrons in modern life            76

CHAPTER IX

HOW WE CARRY MAN'S NEWS

The method of sending the news. The Electron's personal experience.
    A series of forced marches. How man controls the electrons. How
    the electrons reproduce the signals                               86

CHAPTER X

HOW WE COMMUNICATE WITH DISTANT SHIPS

An entirely different means of communication. A surprise to man,
    but not to the electrons. How the electrons produce waves in
    the surrounding aether. How these waves disturb distant
    electrons. The Electron's personal experience. Its description
    of its actions in a wireless telegraph station                    94

CHAPTER XI

HOW WE REPRODUCE SPEECH

Why it is not correct to speak of the electrons as carriers of
    speech. The action of electrons in the working of telephones.
    The Electron's own experience in wireless telephony              106

CHAPTER XII

OUR HEAVIEST DUTIES

A roving commission. How electrons can move gigantic cars and
    trains. The action of electrons in dynamos and motors. How the
    electrons transmit the energy. What makes the motor go           116

CHAPTER XIII

A BOON TO MAN

A simple explanation of how the electrons produce light. How the
    Electron provides a connecting link between matter and the
    aether. How light reaches the earth from the sun. How the
    electrons produce that beautiful luminous effect which man
    calls an "Aurora." How the earth has become a negatively
    charged body. How electrons produce radiant heat. The
    difference between light and heat                                126

CHAPTER XIV

HOW WE PRODUCE COLOUR

What colour is really. How the different colour sensations are
    stimulated by the electrons. The Electron as a faithful
    satellite to the atom. How electrons can produce the different
    aether waves. How the electrons respond to the different waves.
    The production of artificial light. Co-operation of the
    electrons. Man's ridiculously wasteful processes. The
    electrons' secret                                                136

CHAPTER XV

WE SEND MESSAGES FROM THE STARS

The kind of messages referred to. How the electrons have informed
    man of what the stars are made. How man reads the electrons'
    wireless messages. How it is other electrons that enable man to
    read the messages. The real explanation of reflection of light.
    How light is absorbed by some objects. How some substances are
    transparent. Why objects appear coloured. What makes the lines
    in the spectra of stars. The spectroscope                        144

CHAPTER XVI

HOW MAN PROVED OUR EXISTENCE

How man reasoned out a plan for detecting the electron. How the
    electrons altered some lines in the spectrum. The curious
    manner in which the Electron informed man that certain stars
    are approaching this planet, while others are receding from it   158

CHAPTER XVII

MY X-RAY EXPERIENCE

X-rays are an old story to some electrons. The Electron's personal
    experience. A very sudden stop. How electrons made a
    fluorescent screen send out light. The electrons assist the
    surgeon. A curious find. Detecting imitation diamonds. The
    Electron and the mummy                                           166

CHAPTER XVIII

OUR RELATIONSHIP TO THE ATOMS

How the atoms of matter attract one another. What constitutes the
    temperature of a body. What the atoms are made of. An important
    thing still to discover about the atom. The elements. How the
    electrons produce compound substances. The real explanation of
    chemical changes                                                 178

CHAPTER XIX

HOW WE MADE THE WORLD TALK

It was nothing new on the part of the electrons. Exaggerated
    rumours. The electrons and radium. Fast-flying electrons.
    Atomic explosions                                                186

CHAPTER XX

CONCLUSION

The Electron is made to sum up a few of the wonders which it has
    related, in order to emphasise the great services which
    electrons render to man                                          194

APPENDIX                                                             200

INDEX                                                                211




LIST OF ILLUSTRATIONS


                                                                    PAGE

A WELL-KNOWN PHENOMENON PRODUCED BY ELECTRONS             _Frontispiece_

DAMAGE DONE BY A PARTY OF ELECTRONS                                   45

A TOBACCO TIN DEFYING GRAVITATION                                     79

A MOTOR-CAR WITH WIRELESS TELEGRAPH                                   99

A TRAIN IMPELLED BY MOVING ELECTRONS                                 119

PROTECTION AGAINST A DISCHARGE OF ELECTRONS                          129

THE SPECTROSCOPE AND THE ELECTRONS' WIRELESS MESSAGES                149

HOW ELECTRONS PRODUCE X-RAY IMAGES                                   171




CHAPTER I

WHAT THE STORY IS ABOUT


The reason for writing this story is given in the Preface, but the title
is so strange that the reader will wish naturally to know what the story
is about. What is an electron? Is it an imaginary thing, or is it a
reality?

One of the reasons for writing this story in its present form is to help
the reader to realise that electrons are not mythical, but real existing
things, and by far the most interesting things we know anything about.
The discovery of electrons has shed a new light upon the meaning of very
many things which have been puzzles until now. They give us a reasonable
explanation of the cause of light and colour. They provide a new idea of
the constitution of matter. They enable us to picture an electric
current, and they give us definite, though by no means final, answers
to the why and wherefore of magnetism, chemical union, and
radio-activity.

The story is imaginary only in so far that one of the electrons itself
is supposed to tell the tale. But in the endeavour to make the story
interesting, there has been no sacrifice of accuracy in the statements
of fact.

While all names and dates, and many other details, have been kept out
rigidly from the story, a note of the more important of these has been
added in an Appendix for the sake of those readers who may wish to refer
to them.

It will be well to introduce the electron to the reader before leaving
it to speak for itself. We have definite experimental proof of the
existence of electrons, and yet it is very difficult to realise their
existence, for two reasons. In the first place, they are so
infinitesimally small. We count a microbe a small thing; we can see it
only with the aid of a very powerful microscope. Yet that little speck
of matter contains myriads of particles or _atoms_. An atom of matter is
therefore an inconceivably little thing, but even that is a great giant
compared to an electron. Our second difficulty in realising the
existence of an electron is that it is not any form of what we call
_matter_; it is a particle of _electricity_, whatever that may be.

From the earliest experiments it became evident that there were two
distinct kinds of electricity. These were described by the pioneer
workers as _positive_ and _negative_ electricities. To-day we have
definite experimental proof that negative electricity is composed of
separate particles or units. Just as matter is composed of invisible
atoms, so also is negative electricity of an atomic nature. These
particles of negative electricity have been christened electrons,
_electron_ being the Greek word for _amber_, from which man first
obtained electricity. Of course no one can ever hope to see an electron,
but physicists have been able to determine its size and _mass_, its
electric charge, and the speeds at which it moves.

While it has been known for more than a century that _light_ is merely
waves in the all-pervading aether of space, set up by incandescent
bodies, it has been a puzzle always how matter could cause waves in the
aether, as it offers no resistance to the movement of matter through it.
Here we are on the back of a great planet, flying through space at the
enormous rate of one thousand miles per minute, and yet our flimsy
atmospheric blanket is in no way disturbed by the aether through which we
are flying. In the following story we shall see that these electrons
help us towards a solution of this and many other problems; they provide
the missing link between matter and the aether.

But what is this _aether_ of which one hears so much in these days? The
truth is we know nothing of its nature. We cannot say whether it is
lighter than the lightest gas or denser than the densest solid. The
aether, whatever it may be, is as real as the air we breathe. It is the
medium which brings us light and heat from the sun, and which carries
our wireless telegraph and telephone messages. The whole universe is
moving in this great aether ocean.

In order to make the electron's story perfectly intelligible to every
reader, I have added a short explanatory note at the beginning of each
chapter. These notes merely state the facts about which the electron is
speaking.

To make the electron's story as realistic as possible, it has been
necessary to give the imaginary electron perfect freedom of knowledge
concerning itself and its surroundings. In our schooldays we had to
write the autobiographies of steel pens, and such-like, but these
inanimate things had to be endowed with powers of thought, feeling, and
desire. It is very important, however, to remember that an electron is a
particle of negative electricity--_a real existing thing_.




CHAPTER II

THE ELECTRON'S PREFACE


While many scientific men now understand our place in the universe, we
electrons are anxious that every person should know the very important
part which we play in the workaday world. It was for this reason that my
fellow-electrons urged me to write my own biography. My difficulty has
been to find a scribe who would put down my story in the way I desired.
The first man with whom I opened negotiations wished me to give him
dates and names of which I knew nothing. And he asked such stupid
questions about where I was born and who my parents were, as if I were
flesh and blood.

I am pleased to say that my relationship with the scribe who has put
down my story in the following pages has been of the most friendly
description. Apart from a little tiff which we had at the outset, there
has been no difference of opinion. He complained that I related things
in too abstract a form. However, we got over the difficulty by a
compromise; I have allowed him to place what he calls "The Scribe's
Note" at the beginning of each chapter, but it will be understood
clearly that these are merely convenient embellishments, and that I am
responsible for the story of my own experiences.




CHAPTER III

THE NEW ARRIVAL


    _THE SCRIBE'S NOTE ON CHAPTER THREE_

    It will be well to keep clearly in mind that an electron is a
    real particle of negative electricity.

    Electrons have been discovered only within recent years.

    No matter from what substances we take them, they are always
    identical in every respect.

    Some electrons are attached to the atoms of matter in such a way
    that they may be removed easily from one object to another.

    When a surplus of these detachable electrons is crowded on to
    any object, we say that it is charged with negative electricity.

    We speak of the other object, which has lost these same
    electrons, as being charged with positive electricity.

    In this chapter the electron refers to the old-world experiment
    in which a piece of amber when rubbed attracts any light object
    to it.

    For many ages man believed this to be a special property
    belonging to amber alone.

    One of Queen Elizabeth's physicians discovered that this
    property was common to all substances.




CHAPTER III

THE NEW ARRIVAL


It is most amusing to me and my fellow-electrons to hear intelligent
people speak of us as though we were new arrivals on this planet. Dear
me! We were here for countless ages before man put in an appearance. I
wonder if any man can realise that we have been on the move ever since
the foundations of this world were laid. It is man himself who is the
new arrival.

It does seem strange to us that men should be so distinctly different
from one another. We electrons are at a decided disadvantage, for we are
all identical in every respect. I have no individual name--it would
serve no purpose. Even if you could see me, you could not distinguish me
from any other electron. I wonder sometimes if men appreciate the great
advantage they have in possessing individual names. I was impressed
with this thought one fine summer morning. While I was riding on the
back of a particle of gas in the atmosphere, I was carried through the
open window of a nursery just as the under-nurse was putting the room in
order. A little later there was some commotion in the nursery, for the
young mother and her mother had come to see the twin daughters being
bathed by the nurses. The grandmother happened to remark how very much
alike the two little infants were. She said laughingly to the head nurse
that she must be careful not to get the children mixed. But the big
brother, aged five years, remarked that it would not matter really how
much they were mixed until they got their names. Sometimes I wish we
electrons did differ from one another, so that we might each possess an
individual name, but no doubt it is necessary for us all to be exactly
alike.

Long before man had discovered us, he caused us deliberately to do
certain things. He was mystified by the results of his experiments, for
he was not aware of our presence. A few of my fellow-electrons have
rather hazy recollections of being disturbed while clinging to a piece
of amber. They had been disturbed often before in a similar way, by
being rubbed against a piece of woollen cloth, and the result had been
always that a number of electrons let go their hold upon the cloth and
crowded on to the amber. The overcrowding was uncomfortable, but it
happened usually that the surplus electrons found some means of escape
to the earth, where there is no need of excessive crowding.

On the occasion to which I refer, it so happened that the rubbing had
been unusually vigorous and prolonged, so that the electrons were
crowded on to the amber in great numbers. In their endeavour to escape
they produced a strain or stress in the surrounding aether, and this
caused a small piece of straw, which was lying within the disturbed
area, to be forced towards the amber.

What attracted the attention of the electrons was that the man who was
holding the piece of amber removed the clinging straw and replaced it
exactly where it had been lying. In the meantime he had been handling
the amber, and many of the crowded electrons had managed to make a bolt
for the earth by way of the man's body. They did this so very quietly
that the man did not feel any sensation. However, as soon as the amber
was rubbed again, a similar crowd provided the same attractive property.
We electrons became impatient to hear what man would say of our work,
for it was apparent that he had noticed the movements of the straw. You
will hardly believe me when I tell you to what decision these wise men
of the East came. They declared that, in rubbing the amber, it had
received heat and life. As if life could be originated in any such
simple manner!

You can picture our disappointment when we found that man was going to
ignore our presence. Occasionally we were given opportunities of
displaying our abilities in drawing light objects towards pieces of
rubbed amber. But the funny thing was that man got hold of the stupid
idea that this attractive property belonged to the amber instead of to
us. If he had only tried pieces of sulphur, resin, or glass, he would
have found that these substances would have acted just as well. You see
it was not really the substance, but we electrons who were the active
agents.

We had given up all hope of being discovered, when news came along that
a learned man was on the hunt for us. He was crowding us on to all sorts
of substances. He rubbed a piece of glass with some silk, and at first
he was surprised greatly to see light objects jump towards the excited
glass. Of course, we were not surprised in the very least. The only
thing that amused us was to find that he was making out a list of the
different substances which showed attractive properties when rubbed. He
could not, evidently, get away from the idea that it was the substances
themselves that became attractive.

We were sorry that the poor experimenter wasted so much time and energy
in trying to crowd us on to a piece of metal rod. He rubbed and he
rubbed that metal, but it would attract nothing, and I shall tell you
the reason. You know that we electrons hate overcrowding; indeed we
always separate from one another as far as possible when there is no
force pulling us together. We only crowded on to the amber because we
could not help ourselves; we had no way of escape, for amber is a
substance we cannot pass through. But we have no difficulty whatever in
making our way along a piece of metal, and as soon as the rubbing
began, some electrons moved off the metal by way of the man's arm and
body to make room for those being crowded on to the metal from the
rubber. And so there never was any overcrowding, and consequently no
straining of the aether. But it was not long before we found that man had
succeeded in cutting off our way of escape. He had attached a glass
handle to the metal rod, and we were compelled to overcrowd upon the
metal as we could not pass through the glass handle. Neighbouring light
objects were attracted by the excited or "electrified" metal. Even this
demonstration did not put man upon our track.

Perhaps I should explain in passing, that when a glass rod is rubbed
with a silk handkerchief we crowd on to the silk, and not on to the
glass. This leaves the glass rod short of electrons, and the aether is
strained so that light objects are attracted. Man did notice that there
was some difference between a piece of amber and a piece of glass when
these were excited. What the difference was he could not imagine, but to
distinguish the two different conditions he said that the amber was
charged with _negative_ electricity and the glass with _positive_
electricity.

From that time forward man became of special interest to us. We felt
sure that sooner or later he was bound to recognise that we were at work
behind the scenes. It seemed to us, however, that man was desperately
slow in turning his attention towards us, and we tried to waken him up
in a rather alarming fashion, as I shall relate in the succeeding
chapter.




CHAPTER IV

SOME GOOD SPORT


    _THE SCRIBE'S NOTE ON CHAPTER FOUR_

    Men began to make glass plate machines for producing
    electrification on a larger scale.

    The electric spark is produced.

    The electron tells the story of the first attempt to store
    electricity in a glass jar.

    This is what we do now by means of a Leyden jar.

    A sudden expulsion of electrons from one object to another is
    called a discharge of electricity.

    Lightning is a discharge of electrons from a cloud to the earth
    or from cloud to cloud.

    In repeating Franklin's experiment of drawing electricity from
    thunder-clouds, a Russian professor received a fatal shock.




CHAPTER IV

SOME GOOD SPORT


Now I must tell you of a surprise in which I took an active part. Some
man thought he would separate a great crowd of us from our friends. Of
course, he did not think really of _us_, but whatever he may have
supposed he was doing, he succeeded in accumulating greater crowds of us
together than he had done previously. He managed this by making simple
machines to do the rubbing for him on a larger scale. The result was
really too much for us; we were kept crowding on to a sort of brass comb
arrangement from which we could not escape, as the metal was attached to
a glass support. Talk about overcrowding! I had never experienced the
like before, and I felt sure some catastrophe would happen. Suddenly
there was a stampede, during which a great crowd of electrons forced
their way across to a neighbouring object and thence to the earth. I
can assure you it was no joke getting through the air. We all tried to
leap together, but some of the crowd were forced back upon us; then bang
forward we went again, back once more, and so on till we settled down to
our normal condition. Of course all this surging to and fro occupied far
less time than it takes to tell. Indeed, I could not tell you what a
very small fraction of a second it took.

I wish you had seen the experimenter's surprise as we made this jump. We
caused such a bombardment in the air that there was a bright spark
accompanied by a regular explosion. Some men ran away with the idea that
electricity was a mysterious fire, which only showed itself when it
mixed with the atmosphere. Nothing delighted us more, after our own
surprise was over, than to have a chance of repeating these explosions,
to the alarm of the experimenters. But the best sport of all was to
come, and when I heard of it I was so disappointed that I had not been
one of the sporting party. It came about in the following way.

[Illustration: DAMAGE DONE BY A PARTY OF ELECTRONS

_By permission of Dixon and Corbitt and R. S. Newall, Ltd._

_Glasgow_

When a myriad of electrons is discharged suddenly from a cloud to the
earth, it happens sometimes that considerable damage is done. The above
photograph is of a church steeple damaged by lightning in 1875. No
lightning-conductor was provided, so the electrons had to get to earth
by way of the steeple itself, with the disastrous result as shown.]

One learned man thought he had hit upon a good idea. He tried to
crowd a tremendous number of us into some water contained in a glass
jar. Without condescending to think of us, he crowded an enormous number
of electrons from one of his rubbing machines along a piece of chain
which led them into water. The overcrowding was appalling, for it was
impossible to escape through the glass vessel. Things had reached a
terrible state, when the experimenter stopped the machine and put
forward his hand to lift the chain out of the water. Now was the chance
of escape, so the whole excited crowd made one wild rush to earth by way
of the experimenter's body. The rapid surging to and fro of the crowd
racked the man's muscles. I wish I had been there to see him jump; they
say it was something grand. You can imagine how the little sinners
enjoyed the joke; they knew they were safe, as man had no idea of their
existence at that time.

Another man was foolhardy enough to try a similar experiment, and they
say that his alarm was even greater; indeed, he swore he would not take
another shock even for the crown of France. We were all eager to get
opportunities of alarming man, not that we wished him any harm, but we
thought he might pay us a little more attention.

I remember one occasion upon which some of us were boasting of what we
had done in the way of alarming men, whereupon one fellow-electron
rather belittled our doings. He maintained that he had jumped all the
way from a cloud to the earth, along with a crowd of other electrons. In
doing so they had scared the inhabitants of a whole village, for they
alighted upon the steeple of a church, and in their wild rush they
played such havoc among the atoms composing the steeple that they did
considerable outward damage to the great structure.

I may as well confess that we are not free agents in performing these
gigantic jumps; we are compelled to go with the crowd when things are in
such a state of stress. We simply cannot hold on to the atoms of matter
upon which we happen to be located. It is only under very considerable
pressure that we can perform this class of jump, and I beg to assure you
that we are perfectly helpless in those cases where we have been dashed
upon some poor creature with a message of death.

Alas! on one occasion I was one of a party who killed a very learned
man. It was most distasteful to us; we could not possibly prevent it. He
had erected a long rod which extended up into the air, and terminated at
the lower end in his laboratory. Some of us who were in the upper
atmosphere were forced on to this iron rod, and from past experience we
quite expected that we should be subjected to a sudden expulsion to
earth. Indeed we were waiting for the experimenter to provide us with a
means of escape, when suddenly he brought his head too near to the end
of the rod, and in a moment we were dashed to earth through his body. We
learned with deep regret that the poor man had been robbed of his life.

To turn to something of a happier nature, I shall proceed to tell you of
some of my earliest recollections. Remember I shall be speaking of a
time long before man existed--even before this great planet was a solid
ball.




CHAPTER V

MY EARLIEST RECOLLECTIONS


    _THE SCRIBE'S NOTE ON CHAPTER FIVE_

    This great globe upon which we live was once a glowing mass of
    flaming gas.

    It is possible that the whole solar system was once one great
    mass.

    In any case, we have no doubt that the moon is simply the result
    of a part of our glowing mass having become detached.

    In the hottest stars we find only the lightest atoms of matter,
    such as hydrogen gas, the atoms of heavier substances being
    found in stars which have begun to cool down.

    The electrons have been present from the very beginning, and it
    is they who go to make up the atoms of matter.

    We picture an atom of matter as a miniature solar system of
    revolving electrons.

    There is doubtless a corresponding amount of positive
    electricity, but so far we have no evidence of its nature.




CHAPTER V

MY EARLIEST RECOLLECTIONS


Before giving an account of the everyday duties which we perform, it may
interest you to hear something of our early history.

Not only have we been on the move ever since the beginning of this
world, but some of us have clear recollections of this planet long
before it was a solid body. The whole world was a great ball of flaming
gas. I have heard some fellow-electrons say that we were attached to a
greater mass of incandescent gas before the beginning of this world, but
I have no personal recollections of it. But one thing I do remember is a
great upheaval which caused a large mass of gas to become detached from
our habitation. Without any warning a great myriad of our
fellow-electrons were carried away on this smaller mass. At first this
detached mass circled around our greater mass at very close quarters,
but we soon found that our friends were being carried farther and
farther away, until they are now circling around this solid planet at a
comparatively great distance. Man calls this detached mass _the moon_,
and when I have heard children say in fun that they wish they could
visit the man in the moon, I have longed to go and see how it fares with
those fellow-electrons who seem to be separated from us in such a
permanent manner.

After this exciting event, which I have heard described as "the birth of
the moon," our great ball of flaming gas began to cool gradually. But
you will be interested in what happened before the moon's birth. I saw a
crowd of electrons suddenly congregate together along with _something_
else which man has not discovered. Never mind the other part, but
picture a number of electrons forming a little world of their own. There
they went whirling around in a giddy dance. I saw these little worlds or
"atoms" being formed all around, and I feel truly thankful now that I
was not caught in the mad whirl, for these fellow-electrons have been
kept hard at it ever since, imprisoned within a single atom. I have met
a very few electrons who have escaped from within an atom, but I shall
tell you about them later on.

The first thing I noticed was that each of the atoms had practically the
same number of electrons in it. At that time I thought only in an
abstract way, but since then I have learned that these were _hydrogen_
atoms; hydrogen being the lightest substance known to man. Exactly what
happened next I cannot recollect, but my attention was attracted later
to larger congregations of electrons forming other little worlds of
their own. These atoms were, of course, heavier than the hydrogen atoms.
I saw quite a variety of different systems, of which I thought then in
an abstract fashion, but which I know now to be atoms of _oxygen_,
_nitrogen_, _carbon_, _iron_, _copper_, and so on. While man has given
the atoms these distinguishing names, you will understand that the
incidents which I am relating took place long before there was any
appearance of solidity about our planet; these substances were all in a
gaseous state.

After this, I recollect that there was a great envelope of water-vapour
condensed around the planet. Some condensed into liquid water upon the
surface of the globe, while part was suspended in the form of clouds.
Some of my fellow-electrons acted as _nuclei_ or foundations for the
formation of the cloud particles. The water which condensed upon the
earth settled down in the hollows, which had been produced previously by
the immense pressure of the water-vapour envelope. We can hardly believe
it is the same world.

You cannot imagine how strange it was to see the great oceans boiling
and steaming; of course, they were fresh water then. I need hardly tell
you that they have become salt only because the rivers have brought down
sodium into them, and when these sodium atoms unite with chlorine atoms
they form particles of common salt. I know all about this because we
electrons play a very important part in all such combinations.

One very memorable recollection is that of life originating in the
oceans. I wish I could let you into the secret of _the origin of life_,
but, according to the Creator's plan, man must find out for himself.
Your guesses are all wide of the mark.

By the way, perhaps I should explain why I have been selected to write
this biography. The first reason is that I am a free or detachable
electron, and the second point in my favour is that I have had
exceptional opportunities of seeing about me. I have heard men say that
lookers-on see most of the game, and as I have witnessed the gradual
evolution of things, you will understand that I have views of my own. A
casual observer might think that things had deteriorated, for long ago
there were immense monsters upon this planet, and these would put all
modern creatures in the shade as far as size and strength are concerned.
But one of the most interesting things to me has been to watch the
evolution of man, and more especially the gradual development of his
brain. Indeed, sometimes I have wished that I had happened to be an
electron in the brain of a man; but, on the other hand, my career would
not have been of the varied kind which it has been.




CHAPTER VI

MAN PAYS US SOME ATTENTION


    _THE SCRIBE'S NOTE ON CHAPTER SIX_

    Men found that by exhausting the air from glass globes or tubes
    it was possible to pass electric discharges through them, and in
    so doing some very beautiful luminous effects were produced
    within the vacuum tubes.

    It was when experimenting with one of these tubes that a
    scientist suggested that radiant particles were being shot
    across the tube.

    These particles were really electrons, but it was thought at
    that time that they were atoms of matter.

    Another scientist declared, from certain mathematical
    calculations, that there existed extremely small particles of
    something around the atoms of matter, and that it was the motion
    of these in the aether which produced _light_.

    People were not willing to accept this theory.

    Some time later another scientist was able to prove by
    experiment that these particles did exist.

    This was done by means of the spectroscope, as will be related
    by the electron in a later chapter.




CHAPTER VI

MAN PAYS US SOME ATTENTION


From the little I have told you already of our experiences, you will see
that men had been making many experiments in which we electrons took a
very active part. It was disappointing that even although we had
surprised man in so many different ways, he had never become suspicious
of our presence. One day, however, we did begin to hope for recognition.
I was present, with a great crowd of electrons, imprisoned within a
glass globe from which the air had been extracted. We were very pleased
to find that the surrounding space had been cleared of air, for it was
apparent that the experimenter was going to make us jump across from one
end of the glass tube to the other.

A crowd of us had collected on the extremity of a wire, or "electrode,"
at the one end of the tube, while another similar crowd was present on
the other electrode at the opposite end of the tube. While I speak of a
crowd, meaning that there were millions of us, I do not suggest that we
were overcrowded, for we had plenty of elbow-room to move about on the
atoms to which we were attached. All in a moment the scene was changed.
We felt a crowd of electrons pressing us forward and forcing us right up
to the very end of the electrode. We found that the crowd was
approaching by a wire leading into the tube. Soon the crowding had
reached such a condition that we became alarmed; we could see no way of
escape. We were imprisoned by the glass walls, but we soon discovered
that many of the electrons who had been stationed on the other electrode
had deserted their posts and fled along a wire leading out of the tube.
If we could only follow them. It would be a tremendous jump to get over
to the other wire, but the way was fairly clear of air. When the
overcrowding reached a certain point we were literally shot across from
the one electrode to the other. This was the first time I had ever
experienced anything of the kind, but many fellow-electrons had gone
through similar performances for years at the hands of other
experimenters.

However, it was somewhat alarming to be fired off like a rocket across
the tube. What happened after that I cannot recollect, but some time
later I was present in that or a similar tube when I heard the
experimenter say to a friend that he believed there were particles
flying across his tube. We sent news all along the line stating that at
last we had been discovered, and I can assure you that we felt proud.
But our joy was not long-lived, for it turned out that we were
considered to be particles or atoms of matter; the experimenter spoke of
us as "radiant matter." This was a real disappointment.

It took us some time to recover from our disappointment at being
mistaken for clumsy atoms of matter. We are of a higher order of things
altogether. No atom of matter can travel at speeds such as we can. We
cross these vacuum tubes with speeds equal to millions of miles per
minute.

A great many of us were kept busy within vacuum tubes by other
experimenters, but nothing very exciting happened. Indeed, we had lost
all hope of attracting man's attention to ourselves as long as we were
imprisoned within these tubes. In the meantime our hopes were revived by
news which reached us from another quarter.

We heard that a very learned man had declared boldly that there did
exist little particles which revolved around the atoms of matter, and
that it was the motion of these tiny particles in the aether which
produced the well-known waves of _light_. There was considerable
rejoicing among us, for we were anxious to have our services recognised
by man. This great man was not guessing merely; he was willing to prove
by mathematical calculations that we did exist in reality. Of course, we
ourselves required no proof of our existence, but we believed that man
would be convinced. Our high hopes were soon laid low; news reached us
that people were shaking their heads and saying that figures could be
made to prove anything.

After we had settled down to our ordinary duties, we got word that at
last man had really detected us in a flame of gas. This seemed quite
reasonable, for, as I shall relate to you in another chapter, we have a
very lively time of it in a flame of gas. However, when we were
informed that man had discovered us by means of a sort of telescope
arrangement, I, for one, began to doubt the truth of the discovery. Some
time before this I had heard that men were spying at gas flames in the
hope of finding us, and this seemed most ridiculous, for if man could
not see the large congregations of us called _atoms_, how could he
expect to see individual electrons? My ignorance was dispelled when it
was explained that man had not been looking for us directly, but for the
aether waves which we produce. But I have not had an opportunity of
explaining to you how some of us produce waves in the aether; I shall
have to wait till a later chapter. In the meantime I may say that since
this important discovery I have taken some part in an experiment similar
to the historic one wherein we were detected, but of that too I shall
have more to say again.

The rejoicing at this discovery was not confined to us, for men of
science were quick to grasp the importance which was attached to this
new knowledge. We felt that man was bound to acknowledge our services
from that day. The next event was our christening, and this was not all
plain sailing. Indeed, we have been rather annoyed with one name which
some good friends persist in giving us. I refer to the name _corpuscle_,
which we feel to be a sort of nickname, although it may have been
suggested in all kindness. It may be difficult for you to appreciate our
dislike to this name, but it seems to us to savour too much of material
things. It is not dignified; you must remember we are not matter. We are
delighted with what we prefer to call our real name--electron--for that
speaks of electricity. As you know, we are units of particles of
negative electricity, and so this seems a most sensible and suitable
name. But I must hasten to tell of some of our everyday duties in which
we serve man.




CHAPTER VII

A STEADY MARCH


    _THE SCRIBE'S NOTE ON CHAPTER SEVEN_

    The steady motion of electrons from atom to atom along a wire,
    or other conductor, constitutes the well-known "electric
    current."

    The moving electrons disturb the aether around the wire and
    produce what we know as a "magnetic field."

    The electron explains why it is necessary to have a complete
    circuit before any electric current can take place.

    Also how one length of wire may be used to connect two distant
    places provided the two extremities of the wire are buried in
    the earth.




CHAPTER VII

A STEADY MARCH


Personally I knew nothing about marching until quite recently. Indeed,
none of my fellow-electrons seem to have had definite ideas of regular
marches previous to last century. That century is prominent in our
history as well as in man's. There is no doubt that before then we must
have made more or less regular marches through the crust of the earth
and elsewhere; but for myself I have no such recollection previous to
the following occasion.

The experience was not a very exciting one. I found myself passing along
from atom to atom in a copper wire. But what was of special interest to
us was that it became evident that these enforced marches were being
deliberately controlled by man. Of course you will understand that man
knew nothing of our existence at that time. All he knew was that when
he placed a piece of zinc and a piece of copper in a chemical solution,
there were certain effects produced in some mysterious fashion. For
instance, when he connected the top of the two metals in this chemical
cell or "battery" by a piece of wire, he got what he described as an
_electric current_. Now all that happened really was this. The chemical
action in this battery which man had devised caused a rearrangement
among the atoms composing the metals and the solution, with the result
that we poor electrons had to rearrange our domiciles. As an
accumulation of electrons gathered on the zinc, some of us were forced
along the connecting wire towards the copper. As long as the chemical
action in the battery was kept up, so long were we kept on the march
from the zinc to the copper by way of the wire.

Man tried increasing the length of this wire bridge across which we had
to pass, but we had no difficulty in making our way along. But you must
not run away with the idea that we rush along the wire with lightning
speed. Although we can fly through the aether at a prodigious speed, our
progress from atom to atom in a wire is more like a snail-pace. As a
matter of fact, our rate of march is much less than the walking pace of
a man; indeed it may be stated conveniently as so many yards per hour.

Some people may find it difficult to believe that our rate of march is
so very slow. Their front door is a good many yards away from their
electric bell, but it does not take us an hour, or any appreciable part
of a minute, to summon the maid. The secret is that there is a whole
regiment of us along the wire, and before one of us moves on to a
neighbouring atom, another electron must move off that atom and on to
its neighbour, and so on. In this way the electrons at the far end of
the wire commence to move at practically the same moment as those near
the battery.

It has been a source of amusement to me to see people perfectly
mystified by the fact that they can get no electric current unless they
have a complete circuit. What else could they expect? How could man
march if he had no road to march on? You see, the reason for our march
is that we wish to escape from the overcrowding on the zinc, and we are
forced towards the copper. The atoms composing the wire are our
stepping-stones, and if there is not a complete chain of atoms we are
helpless. You have already heard how we can jump an air-space under very
great pressure, but that condition does not exist in the present case.
When we are disturbed by the chemical action of the battery, we should
prefer to have a short-cut from the zinc to the copper, but if the only
path man gives us is by way of a long wire, then we must be content to
travel that road, in order to reach the copper. It is a matter of little
moment to us what arrangement man makes as long as he gives us a
complete path. For instance, he may lead us out from the zinc to a
distant telegraph instrument, and then, instead of providing a second
wire to take us back to the battery, he may conduct us by a short wire
to the earth. We are quite content to lose ourselves in this great
reservoir, provided man places another short wire from the earth to the
copper of the battery at the other end of the line. Then as we slip off
at the one end of the line, an equal number of electrons can climb up at
the other end, and thus enable all our friends in the long wire to keep
up a steady march.

This march of ours is not merely a means of transporting ourselves from
one place to another; it is to enable us to do work. It is only when we
are in motion that we can do useful work, for we must move before we can
disturb the aether, and it is by means of the aether that we transmit
energy.

If you place a magnetic needle or mariner's compass near a wire along
which we are making a steady march, you will find that we can affect our
fellow-electrons who are stationed within the magnetic needle. We cause
the needle to swing round and take up a position at right angles to our
line of march. We succeed in doing this because these electrons in the
magnetic needle are on the move also. But this reminds me that I have
never told you how we produce that aether disturbance which you call
_magnetism_.

When, as children, you played with toy magnets in the nursery, little
did you think that there was a host of tiny electrons amusing you. And
yet we electrons are responsible entirely for all magnetic effects, as I
shall proceed to explain.




CHAPTER VIII

A USEFUL DANCE


    _THE SCRIBE'S NOTE ON CHAPTER EIGHT_

    We believe magnetism to be due to electrons revolving around
    atoms of iron and other magnetic substances, as related by the
    electron in this chapter.

    We have seen that the steady motion of electrons along a wire
    produces a magnetic field around the wire.

    Therefore if we have electrons revolving round and round the
    atoms in a piece of iron, there will be a miniature magnetic
    field around each atom.

    The electron explains why a piece of iron does not show the
    magnetic power locked up within it until it is "magnetised."

    The electron refers to electro-magnets; an electro-magnet is
    simply a piece of soft iron with a coil of insulated wire wound
    around it.

    The iron only shows its magnetic power as long as a current of
    electricity is kept passing through the surrounding coil of
    wire, for reasons which the electron explains.




CHAPTER VIII

A USEFUL DANCE


I may tell you quite frankly that I have never taken part in the
perpetual dance of which I am about to tell you. I am of a free
and roaming disposition, but I have often watched some of my
fellow-electrons at this work. Of course, it is pleasant work, as all
our duties are, now that man acknowledges our services.

We are responsible for the behaviour of the mariner's compass needle. It
is we who cause it to point continually in one definite direction. If we
ceased to dance around the iron atoms in the compass needle aboard a
ship, the man at the helm could not tell in what direction he was going,
and sooner or later he would be almost certain to wreck his vessel. For
this service alone man ought to be grateful to us, but before I have
finished my story, you will find that even this important duty is but a
small affair when compared with many of our other tasks.

There is one matter I should like to make quite clear to you. Although
we electrons are all identical, we have different stations to fill. You
have doubtless become familiar with my roving disposition, and you
probably think of me as a detachable electron. Then there are our
friends who are locked up within the atoms of matter--part and parcel of
the atom. And now I am introducing you to those electrons who act as
satellites to the atoms, revolving around them at a comparatively great
distance, just as the moon revolves around the earth. These are the
electrons which give rise to the magnetism in a piece of iron. There are
other electrons which perform very rapid revolutions around all classes
of atoms, but I shall introduce these friends later on.

[Illustration: A TOBACCO-TIN DEFYING GRAVITATION

That phenomenon known as "magnetism" is due to the steady locomotion of
electrons, as explained in the text. Here we see a large magnet
attracting a tinned iron box which is tethered to the table by two
cords. The result is that the box is supported in the air. The spiral
wires are connected to the electro-magnet, an explanation of which is
given in Chapter VIII.]

I need hardly remark that a piece of ordinary iron does not behave like
a magnet. Indeed, it is fortunate that it does not. If it did, man could
not get along with his work very well. The hammer would stick to the
head of the nail it had struck, the fire-irons would stick to the
fender, while the cook's pots and pans would hold on to the kitchen
range. That would be a very stupid arrangement, but we electrons have
really no say in the matter of arrangement. We are always on the move,
performing a perpetual dance around the iron atoms, but the atoms
arrange themselves in a higgledy-piggledy fashion, so that the electrons
on one atom pull the aether in one direction while others pull the aether
in an opposite direction. In this way the outward effect is not
perceptible. When, however, man places a coil of wire around the iron,
and makes a crowd of electrons march along the wire, these marching
electrons affect the aether, which in turn influences the satellite
electrons which are revolving around the atoms of iron. You may be
somewhat surprised when I tell you that, owing to this aether
disturbance, these satellite electrons are able to produce a
rearrangement among the atoms. If you doubt my word, you may easily
prove the truth of the statement. If you magnetise a long bar of iron
you will find that its length is actually altered. This is due to our
having disturbed the arrangement of the atoms.

Perhaps I should explain that when we force the atoms into their new
condition, we can do so only under the aether stress set up by our
fellow-electrons who are marching in the neighbouring wire. Whenever
their march ceases the aether stress is withdrawn, and the atoms are able
to fall back into their old higgledy-piggledy condition. In this way man
is able to make a piece of iron a magnet and to unmake it as often as he
cares by simply switching on and off the electric current from the wire
surrounding the iron.

If a piece of hard steel is used in place of soft iron, then we find
that the atoms are not so easily disturbed, but when they are once
brought into line with one another, they will remain in their new
condition after the aether disturbance has been withdrawn. It may seem
strange to you that quite a small percentage of carbon atoms added to
the pure soft iron should cause such a marked difference, but the matter
seems plain enough to us. Man was so impressed with the manner in which
the atoms were evidently fixed in their new condition that he spoke of
_permanent magnets_. It is especially fortunate for man that these
pieces of steel do retain their magnetism, and give us a reliable
mariner's compass. But I shall tell you how you may disturb even these
sedate atoms. If you hammer the metal very vigorously, or if you heat it
to redness, you will find that the atoms have been freed from what
appeared to be their permanent position, and they are back to their old
higgledy-piggledy condition, so that we electrons are all opposing one
another. Remember we are hard at work all the time although we may be
giving no outward sign of our activity.

While we render an important aid to man by providing this permanent
magnet for his compass, you will find that a very great deal of our
assistance to man in his everyday life depends upon our behaviour in
soft iron electro-magnets. It is in these that man can control our
behaviour at will. It is through this simple piece of apparatus--the
electro-magnet--that man has been able to accomplish so much in
signalling to his friends at a distance. It is also by means of these
electro-magnets that man can get us to turn an electric motor, and so
on. But I must tell you, first of all, how we enable man to signal to a
distance, or, in other words, how we carry man's news.




CHAPTER IX

HOW WE CARRY MAN'S NEWS


    _THE SCRIBE'S NOTE ON CHAPTER NINE_

    The electron explains wherein its method differs from all other
    methods.

    It is well known that within recent years the old iron telegraph
    wires have been replaced by much lighter copper wires; the
    electron explains the reason for this change.

    It describes how the electrons manage to work the most widely
    used form of telegraph instrument, which is called the "Morse,"
    after its inventor.

    Here we find one of the practical applications of the
    electro-magnet described in the preceding chapter.




CHAPTER IX

HOW WE CARRY MAN'S NEWS


It is we electrons who have so very far outdistanced all material
carriers of news. You must acknowledge that the best runner, the
swiftest horse, the fastest express train, and the prize carrier pigeon,
are all nowhere when compared with us electrons.

But I do not wish to mislead you in any way, and I can speak from
personal experience in this case. We do not race off with man's messages
in the same sense as these other messengers do. Our swiftness of
communication depends upon the simple fact that man provides a whole
connecting regiment of us between the two distant places. And when the
order to march is given we all move off at practically the same moment.
In this way the electrons at the far end of the connecting wire are able
to cause signals there immediately. This is the secret of man's success
in being able to hold immediate communication with his distant friends.
His success is due entirely to the co-operation of us electrons.

My personal experience has been in connection with a very simple
telegraphic arrangement. Indeed, the most of our duties in transmitting
messages are performed with this particular kind of instrument, known as
a "Morse sounder."

At the time of which I speak, I had become attached to an atom of iron
in the end of a long telegraph wire. From this you will probably guess
that my experience was gained some time ago, for man does not use iron
wires nowadays in fitting up telegraph lines. He used iron at first, and
some of these lines still exist, but when he discovered that a very much
lighter copper wire would serve the same purpose, he discarded the heavy
iron wires. Man explained the matter by saying that the copper offered
less resistance to the electric current, and the majority of people were
quite satisfied with this kind of explanation. Of course these are
merely convenient phrases which give man no real reason for the
difference. The real reason is that we electrons are able to move about
from one copper atom to another with very much greater ease than we can
among the iron atoms. That is the reason why man made the change from
iron to copper wires, although he had no idea of the reason at the time.

To return to my experience in connection with a telegraph instrument, I
found that we were being subjected to a series of forced marches. The
whole regiment of electrons along the line made a forward move. The line
of march ended in a short length of fine wire wound around a piece of
soft iron to form an electro-magnet. The end of the wire dipped into the
earth, as I have explained in an earlier chapter.

Now all that we electrons had to do was to make a forward move, halt,
forward again, another halt, and so on. Sometimes the signal to halt was
longer in being given than at other times, but we found that this was
intentional, and that there were two definite lengths of march. I have
explained already how we marching electrons cause an electro-magnet to
attract a piece of iron and let it go again as soon as we cease
marching. It only remains for me to give you a general statement of how
we work the Morse telegraph.

Man has arranged a little lever with an iron end-piece immediately above
the electro-magnet, so that the magnet may attract it. Of course you are
aware that it is the electrons within the soft-iron core of the
electro-magnet who produce the magnetic effect. Every time we electrons
in the surrounding wire make a forward move, the electro-magnet pulls
down the end of the little lever referred to. As long as we keep
marching, so long will the end of the lever remain down, but the moment
we halt, the lever is free to be pulled up by a spring attached to it.
The movements of the lever indicate the length of our long and short
marches, and it is by means of these that man sends signals. All that he
does is to control our march, by means of an electric push and a battery
at one end of the wire, and it is we who produce the signals at the
distant end of the wire. Each time man presses the push we move the
distant lever. When we pull the lever down it is so arranged that it
makes a sound like "click," and when we let it spring up against a stop
it makes another sound not unlike "clack." Our long and short marches
are therefore converted into long and short "click-clacks." Man has made
a simple code of signals representing his alphabet, and right merrily do
we rap out the signals for which we receive orders at the distant end of
the wire, while some one at the other end listens to the sounds we cause
to be made.

I have told you enough of our duties to let you see how we are able to
carry man's news from one part of the earth to any other part. By far
the greatest part of our signalling work is done with this simple Morse
sounder.

It may interest you to note that we can produce those signals far faster
than man can read them. When man found this out he took advantage of our
powers. He made an automatic transmitter which could manipulate the
make-and-break of the battery current far more rapidly than any human
fingers could do. Then as we rapped off the signals with lightning speed
at the distant end, he attached a little ink-wheel to the end of the
moving lever, so that it could mark short and long strokes on a ribbon
of paper passing close to it. Although man could not distinguish the
signals by his ear he was able to read the record of those we caused to
be left upon the paper ribbon.

We have been made to work many other forms of telegraph instruments. In
some of these we control type-letters, while in others we imitate
handwriting, but all these are merely adaptations of our powers of
marching. We are proud of our achievements in rapid signalling, which
all right-thinking people have not been slow to acknowledge.




CHAPTER X

HOW WE COMMUNICATE WITH DISTANT SHIPS


    _THE SCRIBE'S NOTE ON CHAPTER TEN_

    In this chapter the electron deals with that modern
    marvel--_Wireless Telegraphy_.

    Here the aether of space plays a very prominent part.

    The author has given some particulars about the aether in the
    first chapter (_What the Story is about_).

    In conjunction with that, the electron may be left to tell its
    own story.




CHAPTER X

HOW WE COMMUNICATE WITH DISTANT SHIPS


Our duties in this case are totally different from those of which I have
been telling you. While we electrons can do many wonderful things, we
cannot march through space. We may be fired off like bullets from the
sun to the earth, but that is quite another matter. I shall have
something to say about that fact later on. You have seen already that
man can make us jump only a very short distance, even when he has
cleared our path of the obstructing air, as he does in a vacuum tube.

If men were to provide us with a complete path of metal atoms from the
shore to the ship, we could set to work upon the simple plan which I
have described in the preceding chapter. But, needless to say, man has
more sense than to attempt to keep up metallic connection with a ship
going away out to sea.

Even the wisest men were surprised when they heard that we electrons
could signal through space to great distances without any connecting
wires. We ourselves were not surprised. Had we not been doing this very
thing from the foundation of the world? Our fellow-electrons in the sun
have never ceased to communicate with those of us upon the earth. Of
course I am referring at present to those aether waves which man calls
_heat_ and _light_. But the waves which we make to carry man's messages
through space are of the very same nature, the only difference being
that they are much longer, or, in other words, much farther apart. They
do not follow each other so closely, and they do not affect the eye or
the sense of touch. However, these long waves are able to bestir some of
us electrons who are situated at a great distance from the sending
electrons.

Our method of producing such waves in the aether is by surging to and fro
from atom to atom in an upright wire. When we make a rapid to-and-fro
motion we send out great waves in the aether. The original plan adopted
by man was to make us jump across a spark-gap, but in this case also it
was our rapid oscillation to and fro that produced the waves. If we wish
the waves to carry to a great distance, we must club together in
considerable force to supply the necessary energy. The energy which we
can get from a battery and induction coil is not sufficient for any very
long distances. In such cases we require the aid of a _dynamo_, a
machine about which I shall have some experience to relate in another
chapter.

In communicating through space, our position is very similar to that of
two men shouting to one another over a distance. The one man disturbs
the air, thus sending air-waves (sound) over to his friend, and these
waves produce certain sensations which he can interpret. I should like
you to understand that we electrons are upon a higher plane than atoms
of matter. We cause waves in the all-pervading aether, not among clumsy
particles of air. After these aether waves have travelled enormous
distances they retain sufficient energy to disturb electrons situated at
the distant place.

I shall tell you of the first experience I had in this connection. I
found myself attached to an atom of _nickel_, a kind of atom which looks
to us electrons very much like an iron atom, because it has nearly the
same number of electrons composing it, only they are arranged
differently. But I was telling you that I found myself on this nickel
atom sealed up in a small glass tube. Of course there were myriads of
similar atoms all around me, but I did not feel very happy. I was being
urged forward, and yet I could not get across from some atoms to others,
for the nickel was in the form of loose filings. From past experience I
knew that there was a battery along the line somewhere; I could feel the
strain. All of a sudden I was startled to find that I could move
forward. Exactly what happened, I am not at liberty to tell, but this
much I may say, that it was the arrival of some aether waves which
altered the condition of things among the filings in the tube.

[Illustration: A MOTOR-CAR WITH WIRELESS TELEGRAPH

It has become quite a fashion in America to have motor-cars fitted up
for wireless telegraphy. That the electrons play an important part in
telegraphing through space is explained fully in Chapter X.]

We had just started out on our march forward when we received such a
shaking that we found ourselves in the same isolated positions as at
first; we could not get across from one particle to another. More
aether waves arrived, we made a fresh start, then came another rude
shaking, and so on we went starting and stopping. Indeed, it was the
regularity of these long and short marches that gave me the first idea
that we were being controlled by some telegraph operator. We were amused
to find that the rude shaking, of which I have been telling you, was
caused by the action of some of our fellow-electrons. Some of them in
their march around an electro-magnet in the receiving instrument caused
a little lever to knock against our tube and give us a sudden jolt.

I should like you to notice that the energy with which we moved the
telegraph instrument did not come from the distant station. It was a
local battery which worked the receiving instrument, but this battery
was controlled by the incoming aether waves affecting the tube of
filings. There is really no mystery about the matter, but I am anxious
not to take credit for anything more wonderful than we have actually
accomplished.

We electrons have rendered a very great service to man by enabling him
to communicate with his friends who are far out on the ocean, and cut
off from all possible chance of material communication. We are willing
to serve man on land also, though we very much prefer the ordinary
marching arrangement if he will provide a connecting wire. The fact is
that we find it very much more difficult to send aether waves over land
than we do over water.

I have heard some men ask how many different telegraph instruments may
be worked at one place simultaneously without confusion. That is a
question for man himself to answer. We electrons are able to produce any
variety of waves of different frequency or length; it remains only for
man to construct apparatus that will respond only to a definite rate of
waves. I hear that man has made considerable progress in tuning the
wireless instruments.

Some men are eager to get us to carry messages through space across the
great oceans from shore to shore. We shall not refuse, provided man
supplies sufficient energy, but I must admit that we electrons prefer
the submarine cable. Of course man may put this down to our laziness; we
certainly prefer as little severe straining as possible.

I have been telling you of my earliest and only personal experience in
connection with space telegraphy. I understand that greatly improved
methods have been adopted since that time, but I have never happened to
drift in their direction.




CHAPTER XI

HOW WE REPRODUCE SPEECH


    _THE SCRIBE'S NOTE ON CHAPTER ELEVEN_

    In the first part of this chapter the electron explains the part
    it plays in ordinary telephony.

    The reader will picture the transmitting instrument at the one
    end of the line influencing the receiving instrument at the
    distant end.

    Towards the end of the chapter the electron turns its attention
    to the newer subject of _wireless telephony_, which has been
    accomplished now over a distance of several hundred miles.




CHAPTER XI

HOW WE REPRODUCE SPEECH


My scribe suggested a rather clumsy title for this chapter--"Electrons
_versus_ atoms as carriers of speech." I expect he made this suggestion
without much thought, for there are two serious objections to such a
title.

In the first place, we are not carriers of speech. We are controlled by
speech at one end of the telephone line, and we make a reproduction of
the speech at the distant end of the line. No sound passes between the
two places; there is only a movement of electrons along the connecting
line.

My second objection to the hurriedly suggested title is that it is
hardly fair to make any comparison between the achievements of atoms of
matter and those of ourselves. We are not in the same category as
atoms. Besides, we electrons are dependent entirely upon the material
atoms for making our work useful to man. For instance, we might keep on
making waves in the aether for all time, and yet if the atoms of matter
were to pay no heed to those imperceptible waves, man would never be
aware of their presence. Indeed we electrons act solely as go-betweens.
On the other hand, it is only fair to ourselves to point out that a
group of atoms in one town could never communicate with a group of atoms
in a distant town unless we electrons came to their aid. It is true that
over a very short distance the atoms may communicate directly. For
instance, if a heavy blow is given to a large gong, the atoms of metal
may vibrate so energetically that they succeed in disturbing the atoms
of gas of the surrounding atmosphere for some considerable distance. But
in the case of speech, the speaker cannot supply any great energy, so
that he can disturb the atmosphere only to a very limited distance. We
electrons, however, can do yeoman service in this respect. We have
enabled men to speak to one another over immense distances.

The whole affair is very simple. Man speaks and causes the atmospheric
atoms to vibrate and impinge upon a light disc or diaphragm in a simple
instrument which man has named the _telephone_. This vibrating disc
presses upon a myriad of carbon particles contained in a small case or
box, the disc forming one side of the box. When these carbon particles
are pressed together we electrons can get across more easily from atom
to atom. There is a battery urging us forward, but our motion is
dependent entirely upon the manner in which the vibrating disc presses
upon the carbon particles. I cannot describe our movement in the
line-wire as a march; it is in reality a surging to and fro.

You will understand that this to-and-fro motion of the electrons in the
line-wire varies according to the vibrations of the sending disc, which
is controlled by the speaker's voice. At the distant end of the line we
electrons bring our magnetic powers into action. We keep varying the
attractive powers of an electro-magnet, according to the motion of the
electrons in the wire. This ever-changing magnet produces vibrations in
an iron disc which is fixed close to the magnet. This disc is set
vibrating in exact sympathy with the sending disc. When the listener
places this receiving disc close to his ear, the vibrations are carried
by the atmospheric atoms to his hearing apparatus. All that we electrons
have done is to cause one disc to vibrate in exact synchrony with
another distant disc. But that is all that is required, for the
receiving disc will reproduce similar air-vibrations to those set up by
the man's voice at the distant place. I have pointed out already that we
do not attempt to carry the sound. It is true that the atoms of matter
do the hard work, but it is we electrons who enable a group of atoms in
one town to communicate with a group of atoms in a distant town.

It was natural that as soon as man found that he could work his
telegraph instruments without the aid of connecting wires, he should try
to do the same with his telephone instruments. We were sorry when we
found men trying to use the original spark-telegraphy methods for
telephones. While we had no difficulty in operating a telegraph
instrument by means of aether waves and the tube of filings, it was quite
impossible for us to produce telephone vibrations on the same
principle. This spark method was a too rough-and-ready plan. The waves
we produced were like sudden splashes in the aether ocean, whereas we
knew that we must produce regular trains of continuous waves in order to
reproduce telephone vibrations. However, you may be aware that we have
succeeded by a different arrangement of apparatus. Indeed it may
interest you to know that one of my most recent experiences has been in
connection with some wireless-telephone experiments.

Unfortunately I was not in a very favourable position to learn all that
was going on, but it was quite exciting work. I happened to be attached
to an atom of copper in a length of wire which had been run up into the
air on a sort of flag-pole arrangement. I need hardly say that I was not
alone, for by this time you will have become accustomed to picture
myriads of electrons occupying a very small space.

We were set vibrating to and fro with tremendous energy, but what
bothered me most was the great variation in our movements. It was the
nature of these variations which gave me the clue that we were being
controlled by the vibrations of a telephone disc. I can tell you we did
make a complex series of waves in the surrounding aether! These waves
went out through space and influenced some electrons stationed at a
great distance. When these electrons at the receiving station were set
in motion they controlled the electric current from a local battery
which set a second telephone disc vibrating in synchrony with the one at
the sending station.

On questioning some of my fellow-electrons who happened to have been
nearer the transmitting part of the instrument than I had been, I got
some interesting information. They tell me that there was a dynamo and
an arc lamp in our circuit, while the telephone instrument was in a
neighbouring circuit. The electrons surging to and fro in the telephone
circuit influenced those energetic electrons in the arc-lamp circuit to
which the aerial wire was attached. You see that my position in the aerial
wire was not a very advantageous one for observing what was taking
place.

This was truly a great achievement--to enable one man to speak to
another distant hundreds of miles, and without the aid of any connecting
wire. I think you will agree with me that we have excelled all past
records in the world of wonders.




CHAPTER XII

OUR HEAVIEST DUTIES


    _THE SCRIBE'S NOTE ON CHAPTER TWELVE_

    Here the electron explains its behaviour in a dynamo at work.

    The principle of the dynamo was discovered by Faraday in the
    thirties of last century.

    He found that when a coil of wire was moved through a magnetic
    field, there was a current of electricity induced in the moving
    coil.

    Experimental machines were constructed, and after a while a
    practical dynamo was evolved.

    Wires are attached to a dynamo and the electric current is led
    out.

    This current may be conducted to a distant tramway car, and, by
    sending the current through an electric motor, mechanical motion
    is produced and the car propelled along.

    An electric motor is practically the same as a dynamo, but
    instead of turning its coil round in order to produce an
    electric current, we pass a current into the coil and it moves
    round. It will be sufficient to leave the electron to tell its
    own story.




CHAPTER XII

OUR HEAVIEST DUTIES


This is another of those roving commissions in which I have been
privileged to take part on more than one occasion.

If you think of the giant size of an electric tramway car or a railway
train, and try to compare one of these with an electron, such as your
humble servant, it will seem quite ridiculous that I should suggest that
it is we electrons who move those huge vehicles. Yet such is the actual
case.

Of course we require the application of very considerable power to urge
us to so heavy a task. All the energy which we can get from a few
electric batteries might enable us to drive a toy car, but when it comes
to turning the wheels of a real car or train, we require a
correspondingly greater amount of energy.

I may as well tell you quite frankly that we electrons are only the
intermediaries or go-betweens. Indeed, you must have noticed that in
every case we act merely as a connecting link between matter and the
aether, and between the aether and matter.

But what I want to tell you of, is the part we play in moving an
electric car or railway train. It is really all very simple if you could
only see it from our standpoint. Picture a host of us attached to copper
atoms in a coil of wire which is being moved through that disturbed
aether called a _magnetic field_. We are set in motion immediately. It is
true that when we are moved forward into the field we march off in one
direction, only to be arrested and made to move off in the opposite
direction as we leave the field, but it really makes no difference in
our working capabilities as long as we are kept on the move. This is
what is actually taking place in the armature of a dynamo as it revolves
between the poles of the electro-magnet. There is no peace for us so
long as the coil is kept revolving; we are kept in a constant state of
rapid to-and-fro motion.

[Illustration: A TRAIN IMPELLED BY MOVING ELECTRONS

_By permission of Siemens Schuckert Werke_

_Berlin_

It is remarkable that the motion of electrons in an electric conductor
can result in the movement of heavy vehicles. How this comes about is
explained in Chapter XII.]

This is all we electrons do in a dynamo, but when the ends of the outer
circuit or mains are brought into contact with the ends of our
revolving coil, we set the electrons in the mains surging to and fro in
step with ourselves. Man describes this motion of the electrons in the
mains as an _alternating electric current_, but by a simple commutator
on the dynamo he may arrange that we set the electrons marching in one
direction in the mains. This he describes as a _direct electric
current_.

It is a matter of indifference to us whether man drives our coil round
by means of a steam-engine, a water-wheel, or a wind-mill; all that we
electrons want is to be kept surging or vibrating to and fro. Now you
will be able to appreciate how we electrons get up sufficient motion to
enable us to perform what I have described as _our heaviest duties_.

Perhaps you will find it difficult to believe me when I tell you that as
we march along the connecting wire to a distant tramway car we transmit
the energy through the surrounding aether, and not through the wire. This
is our mode of working in every case, whether it be an electric bell, a
telegraph, or telephone. That is to say, while we electrons move from
atom to atom in the connecting wire, it is the disturbed aether
surrounding us which transmits the energy. You must have realised by
this time how very intimate is the relationship between ourselves and
the aether.

To return to the tale of our tramway work, you will picture my
fellow-electrons aboard the car being energised by the incoming current.
Those electrons present in the armature coil of the motor are set into
motion, as also are those in the wire of the neighbouring
electro-magnet. The result is that these two sets of electrons so
disturb the aether and affect one another that the coil is moved round
into a different position. You will remember the experiment of which I
told you, in which a magnetic needle would insist always in taking up a
position at right angles to a wire in which an electric current is
passing. Well, when the motor coil has turned into its new position, we
electrons receive an impulse from our friends in the line-wire which
causes us to retrace our steps in the coil. This action of ours causes
the coil to make a further movement in the same direction as at first.
Again we change our direction of march, and again the coil changes its
position towards the electro-magnet. The sole duty of these electrons in
the armature coil is to keep surging to and fro, while those electrons
in the electro-magnet keep up a steady march in one direction. This
arrangement necessitates the armature coil to keep changing its position
continually, and when we have the armature coil spinning round at a
steady pace, it is easy for man to connect the armature to the axles of
the tramway car and cause us to drive the wheels round.

I need hardly say that it makes no difference to us whether we are asked
to drive a tramway car, a railway train, or a host of machines in a
factory or workshop. All that we electrons in the motor require is to
have sufficient energy passed along to us from our fellows in the
distant dynamo. Again I admit frankly that the atoms of matter play a
very important part in these our heaviest duties, but you will see that
without our active assistance they could not transmit the necessary
energy to a distant car or train.




CHAPTER XIII

A BOON TO MAN


    _THE SCRIBE'S NOTE ON CHAPTER THIRTEEN_

    While it has been known for a long time that _light_ and
    _radiant heat_ are merely waves in the aether, it was not known
    until recently how these waves were produced.

    The discovery of electrons has given us a reasonable solution of
    our difficulty.

    The electron explains the actions of its fellows in this great
    work of producing light and heat.

    Incidentally the electron explains how they produce an aurora in
    the heavens, and how it is that the earth has become a
    negatively electrified body.




CHAPTER XIII

A BOON TO MAN


Every living thing is dependent upon our activities. It is we electrons
who send out heat and light from the sun, and it is we who receive these
on their arrival upon this planet. Our action in the matter is really
very simple, but until man discovered our existence, he was mystified
considerably.

We were amused to hear man say that the atoms of incandescent matter in
the sun produced waves in the aether, and that when these aether waves
fell upon other atoms on this planet, these were set into a state of
vibration, thus producing heat and light. Now if man had only stopped to
think, he would have seen how ridiculous it was to speak of atoms of
matter producing waves in the aether. He ought to have known that atoms
of matter cannot affect the aether, for it offers no resistance to
matter moving through it.

Man might have pictured himself riding on the back of this great planet,
flying through space at a speed very similar to that of a rifle bullet,
and yet even the flimsy blanket of air surrounding the planet is not
disturbed by the aether through which it is rushing.

It is true that the atoms of matter play an important part in the origin
of heat, but the atoms in the sun could no more affect the atoms on the
earth than could a man on the earth push the moon about. It is the very
intimate connection between us electrons and the all-pervading aether
which enables our fellows in the sun to communicate with those of us
upon this planet. Where would man be without us?

[Illustration: PROTECTION AGAINST A DISCHARGE OF ELECTRONS

_By permission of Siemens Schuckert Werke_

_Berlin_

When a man is encased completely in an over-all made of flexible
metallic gauze he is proof against shock due to a discharge of
high-tension electricity. The part played by electrons in the case of
electric shock is explained in Chapter IV.]

I cannot understand wherein man should find any mystery in connection
with this very simple action of ours. You will picture our distant
fellow-electrons making very rapid revolutions around the atoms of
matter to which they are attached as satellites. Just as the moon
circles around the earth, so do we circle around our atoms, but at an
enormously greater speed. Of course the whole length of our orbit is
inconceivably small, and the speed of our revolutions is inconceivably
great. It is our rapid motion through the aether which produces those
waves known to man as radiant heat and light. Some one may ask how it is
that we electrons can disturb the aether while the giant atoms cannot.
The obvious answer is that we are not matter, but electricity; we are
not in the same category as atoms of matter.

To complete the picture which I was drawing, you have only to think of
the aether waves arriving upon this planet and disturbing sympathetic
electrons, causing them to revolve around their atoms in similar fashion
to our distant fellows who are producing the aether waves.

It may be that some people get confused between this action and that of
those electrons who are shot off bodily from the sun towards the earth.
Believe me, there is no connection between the two things. The stream of
electrons shot off from the sun is deflected towards the magnetic poles
of the earth, and as the electrons enter the upper layers of the
atmosphere they produce that beautiful luminous effect which man
describes as an _Aurora_.

I have never taken part in one of these great displays, for, as far as
my recollection goes, I have never been in the sun, although some
fellow-electrons declare that at one time we were all in the same great
glowing mass of which the sun, and every member of the solar system,
formed a part. However that may be, I certainly have no experience of
aurorae, but I have assisted in producing the very same effect upon a
small scale within a vacuum tube. The air remaining in these so-called
vacuum tubes is just as rarified as the air in the upper layers of the
atmosphere, and when we are shot across the tube we act in the same way
as those electrons arriving upon this planet from the sun.

You will observe that as a surplus of electrons arrives upon the earth
from the sun, the earth is naturally a negatively electrified body, but
I need hardly say that the earth does not keep all the electrons which
arrive upon it.

My scribe points out that I am wandering from the story which I set out
to tell in this chapter, so I shall try and please him.

The direct cause of light, whether it be natural or artificial, is the
rapid motion of electrons around atoms of matter. If they revolve at a
comparatively slow speed they produce those aether waves which man calls
_radiant heat_. If these satellite electrons, however, desire to affect
the eye of man, they have to move around at a very much greater speed.
If we travel at too fast a speed, then we cease to cause the sensation
of light. But, believe me, all the waves we make are of the same nature,
no matter what names man has given them. The only difference we can make
in the waves is the rate at which they follow one another. Of course we
can also make them larger or smaller in height, or, in other words, of
greater or less amplitude, but that does not affect their properties.

In the following chapter I shall tell you of some remarkable phenomena
which our different aether waves produce in the brain of man.




CHAPTER XIV

HOW WE PRODUCE COLOUR


    _THE SCRIBE'S NOTE ON CHAPTER FOURTEEN_

    Colour is merely a sensation in the brain.

    What the electrons really produce are aether waves, and these
    give rise to the sensations of colour.

    However, the electrons may claim to produce colour in the same
    sense as we savages produce pain in fellow-men by firing
    rifle-bullets at them.

    The electron explains how some objects appear white, while
    others are red, and so forth.

    It explains also how electrons produce artificial light.

    The electron twits man upon his ridiculously wasteful processes
    of obtaining artificial light.




CHAPTER XIV

HOW WE PRODUCE COLOUR


In the preceding chapter I have been telling you how we electrons
produce waves in the aether ocean. I pointed out that if we make the
waves follow each other at too slow or too fast a rate they fail to
affect man's eyes.

It may seem strange to you that only a very small range of our aether
waves should affect man's visionary apparatus. Of course this limitation
lies beyond our province; we can produce endless variety of aether
waves--it is man's organs which fail to appreciate the bulk of these.
However, there is plenty of variety in the sensations which we can
produce in man. If we make the waves follow each other at a certain
speed, man says he has the sensation of _red_. If we move faster, he
speaks of _orange-colour_, and as we increase our speed he names his
further sensations as _yellow_, _green_, _blue_, and _violet_. Then if
we combine all these waves--that is, if we produce them all at one
time--he says he has the sensation of _white_. If we produce none of
these waves, he calls the result _black_.

While we electrons are very versatile, our actions are dependent in a
great measure upon circumstances. For instance, if an electron is acting
as a satellite to one particular kind of atom, its rate of revolution
around that atom may be very different from that of an electron
similarly attached to another kind of atom. We electrons are all
identical, but the speed of revolution is determined by the kind of
atom. The reason is very simple; electrons revolve around some atoms at
a much greater distance than they would around other atoms. Those making
only the smaller orbits not only get around their atoms in less time,
but they are also travelling at a greater pace. It is this fact which
enables the electrons to produce the various wave-lengths which
stimulate the different colour sensations in the brain of man.

I think you will have no difficulty in seeing how it is that we come to
produce such a variety of wave-lengths--in other words, how we are able
to make the waves follow each other more or less rapidly. You will
understand that we do not produce colours; we merely make various waves
in the aether, and these waves excite the colour sensations in man. I
mention this simple fact, because I hear many people speaking of our
aether waves as "coloured rays," which, of course, is quite a ridiculous
description.

Suppose some of those waves which give rise to the red sensation happen
to fall upon a lump of matter which contains only electrons capable of
producing waves that affect the green sensation. What will happen? There
will be no response, and the object, although viewed by "red light,"
will appear black.

If an object, such as the white paper upon which my scribe is recording
my story, contains a variety of atoms with electrons capable of
revolving at all the different rates which produce colour sensations,
then when "white light" falls upon the object it appears white (all the
colour sensations combined). If, on the other hand, a "red light" only
falls upon it, then only the electrons capable of responding to that
rate of wave will be set in motion, and the object will appear red, and
so on with the other rates of aether waves.

So far I have been telling you what happens when different waves of
light fall upon us. Now I shall endeavour to explain how man has caused
us to produce artificial light. At present all man's methods in this
direction are dependent upon making some substance so hot that it
becomes incandescent. Even his most modern methods seem to us to be
ridiculously wasteful and most roundabout. I shall speak only of the
electric glow lamp, as I have had some experience in connection with
this.

On one occasion I had been taking part in a regular forward march from
copper atom to copper atom in a conducting wire. I had no idea of the
purpose of our march till I suddenly found myself handed over to some
carbon atoms, who were in a very lively state of vibration. We had much
more difficulty in making our way through this substance, and it was the
passive resistance offered to the advance of the electrons who had
preceded me that had driven the carbon atoms into this state of great
excitement. In our march through the copper conductor we had been
offered very little resistance, so that we had left the copper atoms in
peace--at least man could not detect easily any excitement (heat). But
so long as our forced march was maintained among the carbon atoms, so
long did the high temperature exist.

You will understand I and the other marching electrons did not produce
the waves of light sent out by the glow lamp. What we did was to set the
atoms of carbon into a rapid vibratory state, and they in turn caused
their satellite electrons to hasten their pace. Some electrons produced
one rate of waves, and some another rate, but by the time the carbon was
incandescent there were electrons sending out all the variety of
wave-lengths, the combination of which produces the sensation of white.

I have accused man of adopting very wasteful processes, so I had better
explain the matter. In the preceding description of what is occurring in
an electric glow lamp, I have spoken only of those aether waves which
constitute light. But there are myriads of electrons in the carbon of
the glow lamp that never attain the requisite speed to produce those
waves; they revolve around their atoms at too slow a rate. They
certainly disturb the aether, but the crests of the waves are so far
apart that they do not affect the eyes of man. The business of these
waves is to set up heat in the bodies upon which they fall. You may be
surprised to know that in this contrivance of man, called an electric
glow lamp, and, indeed, in all his other artificial light-producers, he
causes far more electrons to produce radiant heat than the desired light
waves. A most wasteful process!

Man has a long way to travel yet before he succeeds in producing
artificial light by a reasonable process. Indeed I doubt if any of you
can realise, as we do, how exceedingly stupid the existing methods are.
Think for a moment of the glow-worm, in which we electrons produce light
without setting up any wasteful heat waves. There is a strong contrast
between this peaceful plan and that of the excited carbon atoms. When
will man succeed in discovering this secret of ours?




CHAPTER XV

WE SEND MESSAGES FROM THE STARS


    _THE SCRIBE'S NOTE ON CHAPTER FIFTEEN_

    It is remarkable that man has been able to discover what the
    distant stars are made of.

    Our knowledge concerning the chemistry of the stars has been
    obtained by means of the spectroscope, in which a beam of light
    from the star is passed through a glass prism.

    The result is the well-known image of the coloured spectrum, in
    which certain well-defined lines appear, according to the
    distant elements originating the aether waves.

    The electron explains the whole subject from its own point of
    view.




CHAPTER XV

WE SEND MESSAGES FROM THE STARS


It is only within recent times that man has observed that we send
messages from the distant stars to this planet. But there is nothing new
to us in this proceeding; we have been busy sending these messages ever
since the solar system was formed. Through all those ages we have kept
on sending these messages, knowing that in time man must come to take
notice of them.

If the subject should happen to be new to you, you will be anxious to
know to what kind of messages I refer. Needless to say, they are
wireless messages--waves in the great aether ocean. The waves, to which I
refer specially, fall within that small range of which I told you
something in the preceding chapter. In other words, they are those waves
to which man has given the name _light_. But what special information
do these waves, coming from the stars, convey to man? They tell him of
what materials these distant stars are made. Needless to say, it is we
electrons who produce those informative waves.

You are familiar with our method of producing waves. You know that we
whirl around the atoms of matter at prodigious speeds, and that
according to the number of revolutions we make per second, we produce
waves of corresponding frequencies.

In an earlier chapter I have hinted that the speed of the revolving
electron is determined by the kind of atom to which it acts as a
satellite. For instance, when electrons revolve around iron atoms they
produce certain wave-lengths, while those moving around hydrogen atoms
produce an entirely different series of waves. But how is man to
recognise these?

It is quite evident that man may gaze at a distant star and be little
the wiser concerning the different lengths of the waves which impinge
upon his eyes. He may observe that the sensation is inclined to red,
from which he may infer that the waves are long ones--that they are
farther apart than some of the waves produced by a white-hot body. But
had man been content to try and decipher our wireless messages in this
rough-and-ready manner, he would never have gained the interesting
information which we have now placed in his hands. How, then, did we
enable man to read our messages?

Our plan may seem to be somewhat mysterious, but I assure you that it is
really very simple. When these aether waves of light fall upon a
triangular prism of glass, the waves are bent out of their normally
straight path. But the point that may seem strange to you, is that those
waves which produce the sensation of red are not bent so much as the
others. The more rapidly the waves follow one another, the greater is
the bending of such a ray from its original direction. In this way the
various wave-lengths are all spread out, so that they form an image like
a coloured ribbon, red at one end, being followed by orange, yellow,
green, blue, and violet. Every man must be familiar with this coloured
spectrum. When some of my fellows are enclosed in drops of water in the
air they produce a great rainbow spectrum across the heavens. But I
must tell you how we electrons succeed in bending these rays of light.

I have told you already how we either absorb or reflect the aether waves
which happen to fall upon us. In most substances it is only those
electrons very near the surface that are disturbed. They succeed in
stopping the waves. They may do this in either of two different ways. If
the satellite electrons are attracted strongly by their atoms, the
electrons will spin around the atoms keeping time to the movements of
the incoming waves, and in this way the electrons take up the energy of
the waves. In doing this, the electrons send out fresh waves in the
aether. This is the real explanation of what man calls _reflection_ of
light.

[Illustration: THE SPECTROSCOPE AND THE ELECTRONS' WIRELESS MESSAGES

The spectroscope is seen in the extreme left of No. 1 photograph. The
instrument is explained at page 207.

The operator is passing an electric current through a glass tube
containing a rarefied gas, causing the gas to become luminous. When he
examines its light through the spectroscope he sees bright lines as
shown in photograph No. 2, and from the position of these lines he can
tell what substance is producing the light. No. 2 is the spectrum of
mercury vapour. No. 3 is part of the spectrum of the sun. Note the dark
lines, as explained in the text.]

In the second case, the electrons are not so firmly attached to their
atoms, so that the incoming waves dislodge them, and they are knocked
about from atom to atom, and in this way the energy of the waves is
frittered away. Man speaks of the light having been _absorbed_ by the
substance upon which it fell. In both cases the only electrons which
take part in these actions are those electrons who can move in
sympathy with the incoming waves.

It will be clear to you that only those of us who are near the surface
of a substance know anything about these incoming waves. The electrons
attached to atoms in the interior of the substance are left in peace,
owing to the defensive actions of our fellows on the outside. But this
is not the case with all substances. There are some congregations of
atoms through which the aether waves can make their way. Man calls such
materials _transparent_; for example, glass and water are transparent
substances. The fact of the matter is that in such substances none of us
are able to respond to the incoming waves, and so we cannot stop them. I
should say almost none of us, for there are always a few electrons
present who happen to be in sympathy with the incoming waves. That is
why no substance is perfectly transparent.

The point concerning which I wish to speak in particular is this.
Although we allow the aether waves to pass through such substances, we do
offer some slight resistance to the passage of the waves; the faster the
to-and-fro motion of the waves, the more resistance do we offer. That
is why the waves of highest frequency are bent farthest from the
straight line when passed through a glass prism. We actually force the
aether waves to travel slower through a piece of glass than through the
air.

Now there should be no mystery concerning our action in a triangular
piece of glass. Whatever combination of aether waves falls upon it, the
different trains of waves are sorted out according to their frequencies.
Suppose, for instance, that aether waves emitted from some incandescent
sodium are passed through a glass prism. The bulk of the electrons
attached to the sodium atoms are capable of revolving at speeds which
produce waves causing the sensation of yellow. Hence there will appear a
very distinct line of yellow light in the spectrum. But why should the
light be in the form of a line? Simply because our aether waves are
passed through a narrow slit in a shutter. But I need not trouble you
with further details of our actions, which, although very simple to us,
may seem somewhat strange to you.

You will understand, however, that we form bright lines in different
parts of the spectrum, according to the kinds of atoms to which we are
attached. It was this fact which attracted man's attention to our
wireless messages. He soon discovered the meaning of these lines, for he
commenced to take exact notes of the different positions in which we
placed these lines. He saw that when we were attached to hydrogen atoms
we always produced three prominent lines; a very distinct line in the
red section, another in the blue part, and a third one somewhat fainter
and farther along in the blue. On the other hand, when attached to
sodium atoms, we produced two very distinct lines in the yellow. When
attached to iron atoms we produced a great variety of lines in the
spectrum. Of course these substances have to be incandescent to enable
us to produce the aether waves.

Now it will be clear to you how we send wireless messages from the
distant stars. These stars are great masses of flaming gases, so that
the satellite electrons are kept busy dancing attendance to excited
atoms. The electrons are constantly sending out aether waves, which reach
this planet. We sort out these waves when man passes them through a
glass prism, mounted in a telescope arrangement which he calls a
_spectroscope_. He then examines the positions of the lines we produce
in the resulting spectrum, and from these he knows what kinds of atoms
are present in the distant star. It is we who have informed man that
there are forty different materials in the sun, the most common of which
are hydrogen, sodium, iron, copper, nickel, and zinc. Of course these
all exist in a gaseous form.

There is one point about which I need hardly trouble you, although it is
worth mentioning in passing. While we produce bright lines in the
spectrum of any incandescent substance on this planet, our messages from
the stars appear as dark lines. The reason for this is that there are
cooler masses of the gases surrounding the incandescent masses forming
the stars, and these cooler gases completely absorb the waves we
produce. So completely are these waves absorbed that blank spaces are
left in the spectrum, and these are the dark lines to which I refer. As
they are in the same positions that the bright lines would have occupied
had the waves reached the earth, it makes no difference to the reading
of our messages.

Curiously enough, some of our actions in forming lines in the spectrum
led to our actual discovery by man; but I shall tell you of this in the
following chapter.




CHAPTER XVI

HOW MAN PROVED OUR EXISTENCE


    _THE SCRIBE'S NOTE ON CHAPTER SIXTEEN_

    Several men of note declared that "little particles" revolved
    around the atoms of matter, and that it was the motion of these
    particles which produced the well-known aether waves of light.

    This idea was suggested by the result of certain mathematical
    calculations.

    It was some time before real experimental proof was obtained.

    The electron tells its own tale of this great discovery.

    When the electron speaks of a spectrum line being shifted up or
    down the scale, it means towards the violet or the red end
    respectively.

    We may picture the spectrum as analogous to the keyboard of a
    piano.

    In the second part of this chapter, the electron explains how it
    has enabled man to discover that certain stars are approaching
    the earth, while others are receding from it.




CHAPTER XVI

HOW MAN PROVED OUR EXISTENCE


We electrons had waited long ages for man to acknowledge our services,
but we did not despise the acknowledgment which a few men accorded us
upon the basis of their mathematical calculations. It was natural,
however, that we should want something more definite than this.

You can imagine our joy when real experimental proof of our existence
was established. Perhaps you think that we should have been satisfied
with this. But even this did not bring acknowledgment from many outside
scientific circles, and not even from all within those circles. As our
services to man are universal, we feel that all men should become
acquainted with our doings. Indeed that was the chief argument used by
my fellow-electrons, who urged me to write this autobiography. The
story of our actual discovery by man is an interesting one.

It all came about in a very simple manner, but in quite a different way
from what most electrons expected. Man reasoned within himself that if
we electrons really did revolve around atoms and thus produce waves in
the aether, as had been suggested, he ought to be able to affect our
movements by disturbing the aether in which we were revolving. Of course
man cannot disturb the aether directly; he must employ some of us to do
this for him. He caused us to produce a very powerful magnetic field,
which, as you know, is a disturbance of the aether. Man did not bother
thinking about _us_ in this connection; he simply sent an electric
current around an electro-magnet, but I have explained to you the very
active part we play in electric and magnetic actions.

From my story in the preceding chapter, you are aware that man had
observed the meaning of the bright lines in the spectrum of any
incandescent body. When he examined the aether waves we send out from
sodium atoms, he found two very distinct lines in the yellow. Because of
the brightness of these lines, man selected a sodium flame to
experiment with in the present case.

You will picture a great host of my fellow-electrons revolving around
the atoms in a sodium flame. The flame was placed between the poles of a
very powerful electro-magnet, and a beam of aether waves (light) produced
by us was directed into the spectroscope. The experimenter focussed all
his attention upon one of the bright yellow lines. He noted very
carefully the exact position in which we placed it. He then produced the
magnetic field around the flame, in which my fellow-electrons were
revolving at a steady pace, and, behold, the line which he was watching
split up into two lines, one taking up a position a little higher up the
spectrum scale, and the other going a little lower down towards the red
end. What could this mean?

Man had no difficulty in knowing the cause of this alteration; indeed,
it was exactly what he had hoped would take place. Of the two new lines,
one represented waves a little shorter, while the other line indicated
waves a little longer or farther apart, than the original waves forming
the single line. This could only come about by some of the electrons
having had their rate of revolution increased, while that of others had
been reduced. These alterations were due to the aether disturbance (the
magnetic field). Those electrons whose orbits happened to lie in one
position had their rate of revolution increased, while those whose
orbits lay in another position had their speed reduced. Man was
convinced at last that we "particles" were real existing things.

Whenever man withdrew the aether disturbance, the electrons fell back
into their natural rate of revolution, and the original single line
appeared in the spectrum.

I took no part in the original experiment which gave absolute proof of
our existence, but since then I have been present in a laboratory when
the same experiment has been repeated.


This is not the only case in which we alter the positions of definite
lines in the spectrum. Indeed, we have given man some interesting
information about the motions of distant stars--information which he
could not have obtained in any other way. We have sent wireless messages
from distant stars, indicating that they were approaching the earth,
while electrons aboard other stars have signalled that they are receding
from the earth. All this may seem mysterious to you, and yet our actions
in the matter are very simple. Indeed, we do nothing but what I have
told you of in the preceding chapters. We send out definite wave-lengths
in the manner described already. But if we are on board a star which is
travelling towards the earth, our waves will naturally follow a little
closer at each other's heels. On the other hand, if the star is receding
from the earth, the waves must be a little farther apart than they would
be if the star were at rest.

You will understand that the electrons are revolving at the same speeds
in both cases, but the forward movement of the star crowds the waves
together, while a receding star stretches them out a little farther
apart. The result at the receiving end is that the crowded waves are
just as though they had come from electrons revolving at a greater speed
than is actually the case. Hence the line appears farther along the
spectrum, up the scale of frequencies, than would have been the case
had the star not been moving forward in the line of sight. Thus if the
hydrogen lines, of which I have spoken elsewhere, should appear higher
up the spectrum than usual, then man knows that the star from which
these waves are coming is approaching the earth.

It will be evident that when known lines in the spectrum are shifted
down the scale (towards the red end of the spectrum), then the rate of
the waves has been decreased, and man knows that the star carrying these
stimulating electrons is receding from him.

You will observe that we electrons perform no new duty in connection
with this matter; it is entirely the motion of the body carrying us that
alters the positions of the lines. But I must hasten on to tell you of
some personal experiences.




CHAPTER XVII

MY X-RAY EXPERIENCES


    _THE SCRIBE'S NOTE ON CHAPTER SEVENTEEN_

    The present generation were all very much interested in the
    discovery of X-rays.

    With the aid of a battery and an induction coil, man causes an
    energetic electrical discharge to pass through a vacuum tube.

    When the flying electrons strike upon a little metal target
    placed in their path, they produce the well-known Roentgen rays.

    We have all become familiar with the great penetrating powers of
    these rays.

    The electron may be left to tell its own story.




CHAPTER XVII

MY X-RAY EXPERIENCES


It was no surprise to us that we could produce what man calls X-rays,
but we were very much surprised at the use to which man put these
splashes which we made in the aether. A limited number of us had been
producing X-rays on our own account for many ages, but I shall tell you
of that in a later chapter, when you will hear how we made the world
talk.

I must tell you of my own experiences in connection with these X-rays,
which I hear some men describe also as _Roentgen rays_. I found myself
once more within a large vacuum tube, and as soon as I felt a crowd of
my fellows pushing me forward, I was quite prepared to be shot across
the tube, as on previous occasions. Personally, I was not prepared for
what was to come. Just as we reached the centre of the tube we collided
with a metal plate or target. It was no joke to be pulled up so suddenly
when travelling at a terrific speed. I noticed at the time that our very
sudden stoppage had a peculiar effect upon the aether. Of course we never
bothered about a name for this disturbance; it is man who requires to
have names for everything. He was quite right to call this aether
disturbance "X-rays," for even now he does not know the real nature of
these. I have heard him describe them as thin pulses in the aether, but
there is something more.

I may as well confess that although we observed this aether disturbance
arising from our sudden stoppage, we paid little attention to it, until
it became apparent that man was continuing to produce these rays for
some special purpose. He had discovered that we could shoot these rays
right through many solid substances which were not transparent to light.
But I have not told you how man came to know that we could produce these
penetrating rays.

On one occasion we were sending out these rays, which, by the way, do
not cause any sensation in man's visionary apparatus. The room was in
darkness. Some of the invisible rays fell upon a collection of small
chemical crystals which were fixed on the surface of a screen. Our
fellow-electrons, who were attached to the atoms of the crystals, were
bestirred into action. They could not reflect the X-rays, but they set
up regular trains of waves in the aether, some of which came within the
range that affects man's vision. Man knew that this chemical screen
could not produce light on its own account, and it became apparent that
the vacuum tube must be sending some aether waves towards the chemical
screen.

As the electrons on the screen produced an aether disturbance different
from that which fell upon it, man called this a _fluorescent screen_.

At first we took merely a passing interest in the experiments which man
made with these X-rays of ours, for it seemed to us as though man
thought them only good enough for amusing his friends. Indeed, we paid
little heed to what he was doing, until we observed that the rays were
being used by surgeons. We were interested at once, for here we could
serve man.

My first experience in this connection was quite interesting. A young
girl had got a needle into her hand while she was playing about, and the
surgeons were at a loss to know where the needle had lodged. We lost no
time in producing X-rays which could penetrate the flesh of the hand,
and reach the fluorescent screen on the other side. The bones of the
hand blocked the way of our rays, but not so completely as the needle
did. Hence we produced upon the screen a faint shadow of the flesh of
the hand, a much deeper image of the bones, and a black shadow of the
needle. This enabled the surgeon to see where the needle was hiding.

Sometimes we were called upon to produce rays for detecting bullets in
the flesh, or for showing the nature of a fractured bone. We were never
surprised to find that our call was to detect a coin in the throat of a
child, but in this connection a big surprise awaited some of us. I was
not one of the party, but I have the information from some
fellow-electrons.

[Illustration: HOW ELECTRONS PRODUCE X-RAY IMAGES

The upper photograph shows the X-ray apparatus in use. The operator is
examining the bones of the lady's hand, which she places between the
X-ray tube and the fluorescent screen. The rays pass through the flesh,
but are obstructed by the bones, the rings, and the bangle, so that a
shadowgraph or image is formed upon the screen, which becomes luminous
where the rays succeed in reaching it. The actual examination is made in
a dark room. Owing to the way X-ray photos are taken (by contact) the
image is reversed in a photograph, so that a left looks like a right
hand.]

A party of electrons were present within an X-ray tube at a large
hospital, when they were called upon to produce rays for examining
the throat of a little girl. They had become so used to this call that
they did not doubt there would be a coin in the child's throat. However,
they lost no time in producing the penetrating rays, and you can imagine
their surprise when they produced the image of a toy bicycle upon the
screen. It seemed ridiculous that such a toy could have entered a
child's throat.

When we had shown the surgeons exactly where the toy was, they set to
work to remove it. The electrons heard later that the operation was
successful in every way. Every one was interested, and we were proud. I
do not wish to appear boastful, but I wonder how many operations owe
their success to these rays which we produce for man.

It was natural that man should try if these searching rays could affect
the chemicals upon a photographic plate, and we soon proved that they
could. It made no difference to us whether man kept the plate sealed up
in its light-proof envelope, or whether he placed the plate within a
wooden box. These protecting covers offered no barrier to our rays. We
produced shadowgraphs of any objects placed between our tube and the
photographic plate.

Two of my early experiences may be of interest to you. The first of
these seemed to me a rather tame affair. Our X-ray tube appeared to be
arranged for the amusement of fashionable folk. One grand lady placed
her hand behind the fluorescent screen, whereupon we produced an image
of the bones of her hand and very dark images of all the many rings upon
her fingers. Several of the rings had enormous diamonds, but it was
after she had gone away that I overheard two gentlemen speaking about
the rings. One asked the other if he had observed the beautiful
diamonds, whereupon the other roared with laughter. It seems that we
proved them to be imitation diamonds, for our rays could not penetrate
them, whereas they have no difficulty in passing through real diamonds.
We therefore produced black shadows of the imitation diamonds. Little
did the grand lady know how we had exposed her sham jewels.

My second experience was a very curious one. I learned that our tube was
being carried to some distance. After a while we were placed beside a
peculiar-looking object, which the men referred to as the "mummy." One
of the men suggested that they should photograph its feet, but before
doing so they darkened the room and set us to work upon the fluorescent
screen. The owner of the mummy got rather nervous as to what we might
disclose, and as the force urging us into action was somewhat erratic at
first, we produced only a very indistinct image. We were greatly amused
at the nervous excitement of the owner; he seemed to think our verdict
was that there were no bones. However, the man with the apparatus soon
got things into better condition, and this enabled us to produce X-rays
satisfactorily. The result was that they secured some excellent
photographs of the hidden bones of the mummy.

Before telling you how we made the world talk, I should like to give you
a clear idea of our relationship to the atoms of matter.




CHAPTER XVIII

OUR RELATIONSHIP TO THE ATOMS


    _THE SCRIBE'S NOTE ON CHAPTER EIGHTEEN_

    We have no doubt that an atom of matter is a miniature solar
    system of revolving electrons.

    These electrons, being negative particles of electricity, would
    repel each other just as any two similarly electrified bodies
    do.

    There must therefore be some equivalent of positive electricity,
    but whether this exists in the form of a sphere or in separate
    particles we have no definite knowledge.

    One atom differs from another in the number of electrons which
    go to make up the atom.

    The electron explains how the atoms of matter are united to one
    another, how different compound substances are formed, and how
    chemical changes take place.




CHAPTER XVIII

OUR RELATIONSHIP TO THE ATOMS


I am sorry that this part of my story must remain incomplete for the
present. I am not free to tell you all I know; you must try and get
behind the scenes on your own account.

One thing I am at liberty to tell you is that my fellow-electrons who
are locked up within the atoms are not without hope that they may gain
their freedom once more at some future time. I know this first-hand, for
I have met some fellow-electrons who have escaped from within an atom,
but I shall delay telling you about these fellows till the succeeding
chapter. My object in mentioning this fact now is to give you confidence
in what I am about to say regarding the nature of the atom.

On one occasion I overheard a conversation between two men who were
discussing the construction of matter. One remarked that the atoms were
the bricks of the universe, whereupon the other asked how the little
bricks were cemented together. I wish that man could have seen a lump of
matter as we see it. He would have been surprised to learn that the
atoms never really touch each other. They are always surging to and fro,
or _vibrating_, and it is this motion which constitutes the
_temperature_ of the body which they compose.

It must be clear, however, that in a solid body one atom attracts
another atom across the intervening atomic spaces. This is another duty
devolving upon us; what we do, really, is to upset the electric balance
between the different atoms, and thus produce electrical attraction.

First of all, perhaps, I should explain that the different kinds of
atoms are simply congregations of different numbers of electrons. Of
course there is the other part, of which I am forbidden to speak--the
part which man vaguely describes as _positive electricity_. However, you
may take it from me that while it is true that the main difference
between an atom of gold and an atom of iron, or of oxygen, is in the
number of electrons it contains, there is a very important difference in
the arrangement of the electrons. You know that they form rings outside
one another, all of which revolve at enormous speeds. The number of
electrons in the different rings varies according to the kind of atom.

It is quite correct for man to speak of the atoms containing certain
definite numbers of electrons, but I should like you to understand
clearly that the exact number of electrons is not permanently fixed; one
or more electrons can slip off one atom and become attached to a
neighbouring atom which happens to be capable of accepting it or them.
It is the interchange of these few detachable electrons that causes one
atom to attract another. In other words, it is the differently charged
atoms which attract each other, just as man crowds a surplus of
electrons on to one object and finds it attracted bodily towards another
object having a deficiency of electrons.

It is this electrical attraction between the atoms which enables us to
build up the particles, or _molecules_, of matter in such a variety of
forms. First of all, we play the most important part within the atoms.
We have formed only a limited number of such atoms. I am not free to
tell you exactly how many, for man has discovered only about eighty of
these different congregations of electrons, each kind of which he calls
an _element_. The way in which we have coupled these different
elementary atoms together must appear remarkable to all thinking men;
there seems to be no end to the possible variety of combinations.

In one case we unite an atom of _chlorine_ to an atom of _sodium_ and
thereby produce a molecule of common salt. In another case we unite an
atom of _oxygen_ to two atoms of _hydrogen_, and the resulting
combination is an invisible molecule of ordinary water.

It has always seemed to me very strange how some men have difficulty in
regard to these combinations. I have heard a man ask how two different
gases, hydrogen and oxygen, when united, should form a liquid, and not a
gas. I wish you could see things as we see them. The atoms are neither
gaseous, liquid, nor solid; they are little worlds of revolving
electrons.

I have spoken of the attraction between atoms, and again between
molecules, in forming a solid body. It will be clear that there is less
of this _cohesive force_ in the case of a liquid, whereas it is absent
entirely in the case of a gas. In this case the molecules have become so
far separated from one another that they cease to attract each other,
and if left free they will soon part company, and spread themselves
broadcast over the face of the earth.

Whether a substance passes into a solid, a liquid, or a gaseous state,
the atoms remain constant, but their vibratory motion is altered very
considerably. However, I was about to tell you that we electrons can
make some very interesting combinations of atoms. Those I have mentioned
so far are of a very simple nature, but we have built up individual
molecules containing hundreds of atoms. We link about a hundred atoms
together and produce a molecule of what man calls _alum_, and we require
to unite about a thousand atoms together to make one molecule of
_albumen_ (the white of an egg).


When man speaks of a chemical change having taken place in a substance,
it is simply the electrons who have made a friendly interchange of
detachable electrons, thereby causing a different assemblage of the same
atoms. During these changes we never alter the nature of the atom. That
little world of revolving electrons known as an atom of gold, remains
always an atom of gold. But you must not run away with the idea that the
atoms will never change. Indeed, man has discovered that the atoms are
not eternal, as I shall explain in the following chapter.




CHAPTER XIX

HOW WE MADE THE WORLD TALK


    _THE SCRIBE'S NOTE ON CHAPTER NINETEEN_

    The discovery of radium is within the memory of all.

    Many exaggerated statements went abroad at the outset, but the
    real facts are full of interest, and they have shed much new
    light on many subjects.

    Three different kinds of radiation were found to be emitted by
    radium.

    At first man could not tell what these were, so he named them
    after the first three letters of the Greek alphabet--Alpha,
    Beta, and Gamma, rays.

    The electron tells the interesting story of these rays, and
    relates the experiences of some fellow-electrons who escaped
    from within a radium atom.




CHAPTER XIX

HOW WE MADE THE WORLD TALK


We electrons were amused at the stir which we unconsciously caused
throughout the civilised world. We had done nothing different from what
we had been doing for ages, but a few men had been taking note of what
we were about, and when the phenomena to which I refer became known to
the world, many wild rumours were circulated.

One of these rumours was to the effect that steam-engines and their
expensive furnaces were to disappear very quickly. If the two last words
had been omitted--I should not say that the prophecy is untrue, but man
has a long way to travel yet before reaching that goal. My fellows
within the atoms have sufficient energy to supply all mankind with power
if he could but unlock even a small fraction of it.

Another statement was that this newly discovered substance, _radium_,
could cure some diseases which man had believed to be incurable. All I
shall say about this is that the statement was an exaggerated one.

Then it was said that radium disproved much of man's scientific
knowledge, but instead of that being so, we electrons have greatly
extended man's knowledge by our radio-active actions. If any man
believed the atoms of matter to be eternal, we certainly disproved that.
Here, in radium, man could see atoms going to pieces.

I have questioned a fellow-electron who escaped from a radium atom as to
what upset their equilibrium, but I find that he does not know, or he
pretends not to know. All he has told me is that he was flung off
suddenly from within the atom with great energy, for he had been
revolving at a tremendous speed. In his sudden flight he passed some
newly formed _helium_ atoms, which contained many of those electrons who
had been his co-partners in the former radium atom. Being an electron,
he was travelling at a far greater speed than these flying atoms of
matter, but he assures me that these helium atoms were going faster
than atoms can travel under any other circumstances.

Another thing that this escaped electron told me was that when he and
his fellow-electrons made a sudden start on leaving the atom of radium
they caused a proper splash in the surrounding aether, just such as we
electrons produce when we are suddenly stopped in an X-ray tube. Man
observed these rays proceeding from radium, but, not knowing the cause
of them, he called them _gamma rays_. We can, of course, produce
radiographs when these rays fall upon photographic plates. Indeed, some
of my fellow-electrons, when escaping from radium, have produced rays
sufficient to penetrate a six-inch boulder and affect a photographic
plate lying beneath the boulder. In time man recognised these rays as
X-rays.

Man did not find only these rays--he discovered that electrons were
escaping, but before he had recognised what we were, he had named us
_beta rays_. These fast-flying electrons have had experiences which
never fall to electrons except when escaping from an atom. Their
velocity is so great that they can be shot right through a sheet of
aluminium foil. If these escaped electrons are allowed to settle on any
object, they will necessarily cause an overcrowding, or, in other words,
the object will become negatively electrified.

The one thing that puzzled man most was to find out what the helium
atoms were. He had named them _alpha_ rays, but as he found he could not
get them to penetrate even a thin sheet of paper, he was confident that
they must be atoms of matter. It was only when he had gathered
sufficient to examine the spectrum that he found these to be helium
atoms.

I think what really made the world talk was the fact that electrons were
escaping from what had been supposed to be an eternal habitation. In
other words, this material radium was actually going to pieces. That is
to say, _gradually_, as far as man is concerned, for, looking at it from
our point of view, the word _gradual_ seems out of place entirely. The
breaking up of an atom is really of the nature of an explosion. It is a
continual bombardment that is proceeding in radium. Why man is apt to
think of it as a gradual effect is that there is such an enormous
number of atoms in a tiny speck of radium, that even the incessant
series of explosions will take a very long time to break down the whole
of the small particle.

Electrons differ in their opinions as to whether man will succeed in
drawing upon this internal energy of the atom. My own difficulty is
that, having been a roaming electron at all times, I have no idea
regarding the cause of the atomic explosions. I have remarked already
that the electrons locked up within the atoms possess more energy than
man could ever use. If all these electrons were deprived of their
energy, the atoms of matter would cease to exist, and man, where would
he be?




CHAPTER XX

CONCLUSION


    _THE SCRIBE'S NOTE ON CHAPTER TWENTY_

    Not many of us have realised the true importance of electrons in
    the Creator's plans.

    In the following short chapter the electron is made to sum up a
    few of the wonders which it has related, in order to focus our
    attention upon the grand place which the electrons occupy in the
    universe.




CHAPTER XX

CONCLUSION


From what I have told you of myself and my fellow-electrons, it must be
apparent that we are of tremendous importance to man. I have told you
something of the part we played in building up this world--how we not
only form the atoms of matter, but also hold these bricks of the
universe together. I have given you a rough sketch of the composition of
these bricks.

You must have realised also that without us the whole universe would be
in darkness. There would be no light, no heat, and consequently no life.
Indeed, there could be no material existence without us.

Where would man be if we failed to perform our mission? He could not
exist if we even neglected a few of our duties. Not only do we form the
atoms of which his body is composed, also holding these together, but
we produce all those chemical changes within his body which are
absolutely necessary to maintain life. His very thoughts are dependent
upon our activities.

I have told you how we send man's messages across the earth, and how we
transmit power from place to place. Also how we have enabled man to gain
knowledge of the distant stars, and to examine the bones of his living
body.


If man could cross-examine me or any of my fellows, I expect the first
question would be--What are you electrons made of? But man must find
this out for himself. The Creator has placed man in a world full of
activity, and it is of intense interest to man to discover the meaning
of all that lies around him. That is why I have been bound over by my
fellows to tell you only so much of our history as man has discovered.
But I am disclosing no secret when I admit that our very existence as
electrons is dependent upon the aether.


If I can find another scribe to write a revised biography for me a few
hundred years hence, I shall have a much more interesting tale to tell,
for many of our doings, of which man knows nothing at present, will be
secrets no longer by that time.




APPENDIX


    _THE SCRIBE'S NOTE ON APPENDIX_

    As explained by the author in Chapter I., this appendix has been
    added for the sake of those readers who may wish further details
    than have been given in the electron's story.

    It is only necessary to give a brief notice of the more
    important particulars, as the author has written recently upon
    this subject in a popular form.[1]

[Footnote 1: "Scientific Ideas of To-day." By Chas. R. Gibson, F.R.S.E.
(London: Seeley & Co., Ltd. Five shillings net.)]




APPENDIX


It was known two thousand years ago that when a piece of amber was
rubbed with a woollen cloth, the amber would attract light objects
towards it. Amber was considered to be unique in this respect.


About the year 1600, one of Queen Elizabeth's physicians, Dr. William
Gilbert, inquired into this attractive property of amber. He found that
many other substances possessed the same property. Indeed it is common
to all substances in some degree. We say the amber or other object is
"electrified."


It was observed by the early experimenters that there were two kinds of
electrification. To one of these they gave the name _positive
electricity_, and to the other _negative electricity_.


Every electrified object will attract an object which is not
electrified, and two objects which are oppositely electrified will
attract one another also. But two objects which are similarly
electrified will repel each other.


Man got tired of rubbing objects by hand, so he fitted up simple
machines in which glass cylinders or plates were rubbed against leather
cushions. The electricity was then collected by little metal points
supported on an insulated metal sphere.


The experiment of attempting to store electricity in a glass vessel
filled with water was made at the University of Leyden (Netherlands).
The water was replaced later by a coating of tin-foil on the inner
surface, while a similar metallic coating on the outside took the place
of the experimenter's hand. These jars are called _Leyden jars_, after
the place in which the discovery was made.


About 1790, Professor Galvani, of Italy, observed that the legs of a
freshly killed frog twitched at each discharge of an electrical machine.
Later he found that the same twitching occurred when he connected
certain parts with a piece of copper and zinc. He believed this to be
due to "animal electricity" secreted within the frog.


Professor Volta, also of Italy, proved that Galvani's idea was wrong,
and that the electricity resided in the metals rather than in the frog.
He showed that when two pieces of dissimilar metal were put in contact
with one another, there was a slight transference of electricity between
them. He constructed a pile of copper and zinc discs, with a moist cloth
between each pair or couple, and by connecting wires from the top copper
disc to the lowest zinc disc he was able to show that an appreciable
current of electricity was produced. Later he placed a piece of copper
and a piece of zinc in a vessel containing acidulated water, whereupon
he found that a steady current of electricity was obtained. This was the
invention of electric batteries.


The phenomena of _magnetism_ were known to the ancients, but it was not
until the nineteenth century that we found any real connection between
electricity and magnetism. In 1819, a Danish philosopher, Hans
Christian Oersted, discovered that an electric current passing in a wire
affected a magnet in its neighbourhood. If the magnet was supported on a
pivot, after the manner of a compass needle, it would turn round and
take up a position at right angles to the wire carrying the electric
current.


The molecular theory of magnetism presumes that every molecule of iron
is a tiny magnet, having a north and south pole. In a piece of
unmagnetised iron, these tiny magnets are all lying so that they
neutralise one another. When they are turned round so that their north
poles are all lying in one direction, then the iron is said to be
magnetised.


The electron theory of magnetism does not do away with the older
molecular theory just referred to. The electron theory goes a step
farther, and tells us that these molecules are magnets because of a
steady motion of electrons around the atoms of iron.


It was discovered in 1825 that when an electric current was sent through
an insulated wire wound around a piece of soft iron, the iron became a
magnet; when the current was stopped the magnetism disappeared. Such
magnets are called _electro-magnets_. If a piece of hard steel is
treated in the same way it becomes a _permanent magnet_. It was this
intimate connection between electricity and magnetism, or, in other
words, the invention of these electro-magnets, which brought us electric
bells, telegraphs, telephones, dynamos, and electric motors.


It should be noted that while iron is attracted by either pole of a
magnet, there is such a thing as magnetic repulsion. This, however,
takes place only between two magnets, and then only between like poles.

       *       *       *       *       *

Some German physicists made a number of electrical experiments with
vacuum tubes. When Sir William Crookes (England) was experimenting with
similar vacuum tubes he suggested that matter was in a "radiant" state
during the electric discharge within the tubes.


In 1880, H. A. Lorentz, of Amsterdam, declared that light was due to the
motion of small particles revolving around the atoms of matter.


Professor Zeeman, of Holland, produced experimental proof of Lorentz's
theory. He showed that the revolving "particles" were influenced by a
powerful magnetic field, in the manner explained in the electron's
story. This discovery was made in 1896, or sixteen years after Lorentz's
declaration. It was Dr. Johnstone Stoney, of Dublin University
(Ireland), who christened these particles "electrons."


The X-rays were observed for the first time by Professor Roentgen, of
Germany, in 1895. The screens used for viewing the luminous effects
produced by the X-rays are coated with very fine crystals of _barium
platinocyanide_. These screens were in use for another purpose previous
to the discovery of X-rays.


We know now that _chemical affinity_ is merely electrical attraction
between the atoms of matter.


The spectroscope consists of a glass prism, or series of prisms, mounted
between two metal tubes. One tube is provided at one end with a vertical
slit, through which the light that is to be examined is passed. At the
other end of the tube is a lens, so that the beam of light from the slit
emerges through the lens as a pencil of parallel rays. The pencil of
light then falls upon the glass prism, striking it at an angle. In
passing through the prism, the light is bent round so that it enters the
second tube, which is simply a small telescope. The prism separates the
aether waves according to their wave-lengths, and produces the well-known
coloured spectrum, which is magnified by the telescope. The reason for
the bending of the different waves is explained in the electron's
story.




INDEX


Absorption of light, 148

Aether, the, 24

Aether waves, 96, 131, 133, 137, 146, 148, 163

Alpha rays from radium, 190

Alternating electric current, 121

Amber electrified, 32, 34 to 37, 201

Artificial light, 140, 142

Atoms breaking up, 188, 190

Atoms co-operating with electrons, 108, 123

Atom's internal energy, 187, 191

Atoms of matter, 52, 54, 78, 128, 180, 184

Attraction between atoms, 180

Attraction, electrical, 35, 202

Attraction, magnetic, 78, 205

Aurora, 132

Automatic telegraph transmitter, 91


Battery, electric, 70, 203

Beginning of the world, 53

Beta rays from radium, 189

Birth of the moon, 52, 54

Bricks of the universe, 180, 195


Chemical affinity, 206

Chemical combinations, 56, 182

Chemistry of the stars, 52, 55, 144, 153

Chlorine atoms, 56, 182

Cloud formation, 56

Circuit, earth, 72

Coherer, tube, 98

Cohesive force, 183

Colour, 136

Compass needle, 77

Complete electric circuit, 71

Conductors, 37, 68

Connecting link between aether and matter, 118, 127

Corpuscles, 66

Crookes, Sir William, 205

Current of electricity, 68


Dark lines in spectrum, 154

Detachable electrons, 78, 181

Detecting imitation diamonds, 174

Direct electric current, 121

Discharge of electricity, 42

Discharge through a vacuum, 60

Discovery of electrons, 160, 206

Discovery of X-rays, 169

Dynamo, 116, 118


Earth circuit, 72

Electrical discharge, 42

Electricity, positive, 23, 32, 39, 52, 180

Electricity, negative, 23, 32, 39

Electric battery, 70

Electric current, 68, 70

Electric motor, 116, 122

Electric shock, 47

Electrified objects, 37, 38, 201

Electro-magnets, 76, 81, 83, 118, 205

Electrodes, 61

Electrocution, 49

Electron as a go-between, 118

Electron, derivation of the word, 23

Electron, discovery of, 160, 206

Electrons, 25, 32, 66, 78, 138, 162, 195

Energy transmission through the aether, 73, 121

Energy within the atom, 187, 191


Field, magnetic, 68, 76, 118

Fluorescent screen, 169, 206


Galvani's discovery, 202

Gamma rays from radium, 189

Gilbert's discovery, 201

Glass, electrified, 37, 38

Glass prism, 147, 152

Glow-lamp, electric, 140, 141

Glow-worm, 142


Heat, radiant, 126, 131, 133, 142

Helium atoms, 188, 190

Hydrogen atoms, 55, 182


Insulators (non-conductors), 37, 47

Iron atoms, 77

Iron wires discarded, 88


Lamp, electric, 140

Leyden jar, 42, 202

Light, 23, 60, 64, 133

Light absorbed, 148

Light, artificial, 140, 142

Light, reflected, 148

Lightning, 42, 48

Lines in the spectrum, 152, 154, 160, 162

Lorentz's declaration, 206


Magnetic attraction, 78, 205

Magnetic field, 68, 76, 118

Magnetic repulsion, 205

Magnetism, 73, 76, 203, 204

Magnetism and electricity, 73

Magnets, electro-, 76, 81, 83, 205

Magnets, permanent, 83

Mariner's compass, 77

Matter, 52, 54

Metal electrified, 37, 38

Molecules of matter, 181, 183

Moon's birth, 52, 54

Morse telegraph, 88

Motion in line of sight, 162

Motor, electric, 116, 122


Negative electricity, 23, 32, 39


Oersted's discovery, 204

Oxygen atoms, 182


Permanent magnets, 82

Positive electricity, 23, 32, 39, 52, 180

Prism of glass, 147, 152


Radiant heat, 131, 133, 142

Radiant matter, 63, 205

Radium, 188

Rainbow, 147

Rays from radium, 189, 190

Reflection of light, 148

Repulsion, electrical, 202

Repulsion, magnetic, 205

Roentgen rays, 167

Roentgen's discovery, 168, 206


Sea, cause of saltness, 56

Shock, electric, 47

Silk, electrified, 38

Sodium atoms, 56, 182

Spark, electric, 44

Spectroscope, 152, 154, 207

Spectrum, 144, 147, 152, 154

Speed of electrons in conductor, 70

Stars approaching the earth, 162

Stars, constituents of the, 52, 55, 146

Stoney, Dr. Johnstone, 206

Sun, constituents of the, 154

Sun's heat, 128, 131


Telegraph signals, 90

Telegraphy, wireless, 95

Telephone, 109

Telephony, wireless, 110

Temperature, 180

Tramway, electric, 117, 118, 122

Transparent substances, 149


Vacuum tubes, 60, 61, 132, 205

Velocity of electrons, 70

Volta's discovery, 203


Waves in the aether, 96, 133, 137, 146, 148, 163

Wireless messages from the stars, 162

Wireless telegraphy, 95

Wireless telephony, 110


X-rays, 166, 206

X-rays from radium, 189

X-ray photography, 173


Zeeman proves existence of electrons, 161, 206


Printed by BALLANTYNE, HANSON & CO.
Edinburgh & London




       *       *       *       *       *




Transcriber's Note

    The following changes have been made to the original text:

    Page xi:  "always necessary, How" changed to "always necessary. How"
    Page 205: "vacuum tubes, When" changed to "vacuum tubes. When"
    Page 214: "Negative electricity, 23, 32, 9" changed to "Negative
	          electricity, 23, 32, 39"



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