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

CHAPTERPAGE
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

CHAPTER I
THE BIRTH OF THE SCIENCE OF ELECTRICITY