Chapter I: Preface

I gladly take this opportunity of acknowledging the generous assistance I have received in the preparation of this book.

I am indebted to the following firms for much useful information regarding their various specialities:--

Chloride Electrical Storage Co. Ltd.; General Electric Co. Ltd.; Union Electric Co. Ltd.; Automatic Electric Co., Chicago; Westinghouse Cooper-Hewitt Co. Ltd.; Creed, Bille & Co. Ltd.; India Rubber, Gutta Percha, and Telegraph Works Co. Ltd.; W. Canning & Co.; C. H. F. Muller; Ozonair Ltd.; Universal Electric Supply Co., Manchester; and the Agricultural Electric Discharge Co. Ltd.

For illustrations my thanks are due to:--

Marconi’s Wireless Telegraph Co. Ltd.; Chloride Electrical Storage Co. Ltd.; Harry W. Cox & Co. Ltd.; C. H. F. Muller; W. Canning & Co.; Union Electric Co. Ltd.; Creed, Bille & Co. Ltd.; Ozonair Ltd.; Kodak Ltd.; C. A. Parsons & Co.; Lancashire Dynamo and Motor Co. Ltd.; Dick, Kerr & Co. Ltd.; Siemens Brothers Dynamo Works Ltd.; Vickers Ltd.; and Craven Brothers Ltd.

Mr. Edward Maude and Mr. J. A. Robson have most kindly prepared for me a number of the diagrams, and I am indebted to Dr. Myer Coplans for particulars and a diagram of the heat-compensated salinometer.

I acknowledge also many important suggestions from Miss E. C. Dudgeon on Electro-Culture, and from Mr. R. Baxter and Mr. G. Clark on Telegraphy and Telephony.

Amongst the many books I have consulted I am indebted specially to _Electricity in Modern Medicine_, by Alfred C. Norman, M.D.; _Growing Crops and Plants by Electricity_, by Miss E. C. Dudgeon; and _Wireless Telegraphy_ (Cambridge Manuals), by Prof. C. L. Fortescue. I have derived great assistance also from the _Wireless World_.

Finally, I have to thank Mr. Albert Innes, A.I.E.E., of Leeds, for a number of most valuable suggestions, and for his kindness in reading through the proofs.

W. H. McC.

LEEDS, 1915

CONTENTS

CHAPTER PAGE
I. THE BIRTH OF THE SCIENCE OF ELECTRICITY 1

II. ELECTRICAL MACHINES AND THE LEYDEN JAR 9

III. ELECTRICITY IN THE ATMOSPHERE 18

IV. THE ELECTRIC CURRENT 27

V. THE ACCUMULATOR 38

VI. MAGNETS AND MAGNETISM 44

VII. THE PRODUCTION OF MAGNETISM BY ELECTRICITY 56

VIII. THE INDUCTION COIL 61

IX. THE DYNAMO AND THE ELECTRIC MOTOR 66

X. ELECTRIC POWER STATIONS 75

XI. ELECTRICITY IN LOCOMOTION 83

XII. ELECTRIC LIGHTING 93

XIII. ELECTRIC HEATING 109

XIV. ELECTRIC BELLS AND ALARMS 116

XV. ELECTRIC CLOCKS 124

XVI. THE TELEGRAPH 128

XVII. SUBMARINE TELEGRAPHY 144

XVIII. THE TELEPHONE 154

XIX. SOME TELEGRAPHIC AND TELEPHONIC INVENTIONS 171

XX. WIRELESS TELEGRAPHY AND TELEPHONY--PRINCIPLES AND
APPARATUS 179

XXI. WIRELESS TELEGRAPHY--PRACTICAL APPLICATIONS 203

XXII. ELECTROPLATING AND ELECTROTYPING 213

XXIII. INDUSTRIAL ELECTROLYSIS 224

XXIV. THE RÖNTGEN RAYS 228

XXV. ELECTRICITY IN MEDICINE 241

XXVI. OZONE 247

XXVII. ELECTRIC IGNITION 253

XXVIII. ELECTRO-CULTURE 258

XXIX. SOME RECENT APPLICATIONS OF ELECTRICITY--AN ELECTRIC
PIPE LOCATOR, ETC. 266

XXX. ELECTRICITY IN WAR 274

XXXI. WHAT IS ELECTRICITY? 287

INDEX 295

LIST OF PLATES

PLATE IN COLOUR: THE MARCONI TRANSATLANTIC WIRELESS STATION AT
GLACE BAY, NOVA SCOTIA _Frontispiece_

FACING PAGE
HYDRO-ELECTRIC POWER STATION 30

(_a_) EXPERIMENT TO SHOW MAGNETIC INDUCTION 48

(_b_) EXPERIMENT TO SHOW THE PRODUCTION OF MAGNETISM BY AN
ELECTRIC CURRENT 48

(_a_) LINES OF MAGNETIC FORCE OF TWO OPPOSITE POLES 50

(_b_) LINES OF MAGNETIC FORCE OF TWO SIMILAR POLES 50

A TYPICAL DYNAMO AND ITS PARTS 70

LOTS ROAD ELECTRIC POWER STATION, CHELSEA 76

POWER STATION BATTERY OF ACCUMULATORS 80

ELECTRIC COLLIERY RAILWAY 86

TYPICAL ELECTRIC LOCOMOTIVES 90

NIGHT PHOTOGRAPHS, TAKEN BY THE LIGHT OF THE ARC LAMPS 96

WHERE ELECTRICAL MACHINERY IS MADE 120

SPECIMEN OF THE WORK OF THE CREED HIGH-SPEED PRINTING TELEGRAPH 140

LARGE ELECTRIC TRAVELLING CRANE AT A RAILWAY WORKS 164

(_a_) MARCONI OPERATOR RECEIVING A MESSAGE 188

(_b_) MARCONI MAGNETIC DETECTOR 188

RÖNTGEN RAY PHOTOGRAPH OF BRITISH AND FOREIGN FOUNTAIN PENS 240

BACHELET “FLYING TRAIN” AND ITS INVENTOR 272

(_a_) CAVALRY PORTABLE WIRELESS CART SET 280

(_b_) AEROPLANE FITTED WITH WIRELESS TELEGRAPHY 280

ELECTRICITY