Chapter I: 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