CONTENTS

PAGE
INTRODUCTION[xi]
Part I
CHAPTER I.—SOME GENERAL EXPLANATIONS[3]
An Invisible World-power—Generating Electricity—What a Boy CanDo—Inexpensive Tools—Some Practical Advice
CHAPTER II.—CELLS AND BATTERIES[12]
Simple and Inexpensive Cells—How to Make Cells and Batteries—APlunge-battery—A Storage-battery—Dry-cells and Batteries
CHAPTER III.—PUSH-BUTTONS AND SWITCHES[33]
How to Make Push-buttons—Switches and Cut-outs—Table-jackSwitches—Binding-posts and Connectors—Lightning-arresters and Fuse-blocks—Some Practical Precautions
CHAPTER IV.—MAGNETS AND INDUCTION-COILS[54]
Simple and Horseshoe Magnets—Induction-coils—An ElectricBuzzer—Electric Bells—A Large Induction-coil—Circuit-interrupters
CHAPTER V.—ANNUNCIATORS AND BELLS[78]
A Drum-sounder—A Simple Annunciator—A Double Electric Bell—AnElectric Horn—How to Make a Burglar-alarm—Electric Call-signals—Clock-alarms—A Dining-table Call
CHAPTER VI.—CURRENT-DETECTORS AND GALVANOMETERS[102]
How to Make Detectors—An Astatic Current-detector—An AstaticGalvanometer—A Tangent Galvanometer
Part II
CHAPTER VII.—ELECTRICAL RESISTANCE[125]
Governing the Electric Current—Ohm’s Law—Resistance-coils andRheostats—How to Make Simple Apparatus—Liquid Resistance—Importance of Switches—Uses of aHouse-current—Running a Sewing-machine, Fan, or Toys—An Easy Method for a Boy’s Use
CHAPTER VIII.—THE TELEPHONE[156]
Vibratory Waves—A Bladder Telephone—A Single (Receiver) Line—Planof Installation—A Double-pole Receiver—The Transmitter—Another Form of Transmitter—The WiringSystem—A Telephone Induction-coil—An Installation Plan—A Portable Apparatus
CHAPTER IX.—LINE AND WIRELESS TELEGRAPHS[190]
A Ground Telegraph—How to Talk from House to House—The Morse TelegraphCode—A Story of Edison—How Detectives Used the Code—Wireless Telegraphy—Its True Character—Howa Boy Can Make a Practical Apparatus—Receiving and Sending Poles—Induction-coils, Batteries, Coherers andDe-coherers, etc.—Working Plans in Detail—Aërograms Across the Atlantic and, perhaps, Around the World
CHAPTER X.—DYNAMOS AND MOTORS[229]
Dependence of Modern Electricity upon the Dynamo—A Field of Force Cuttinganother Field of Force—Varieties of Dynamos—Simpler Forms ofGenerators and Motors—How to Make a Uni-direction Current Machine—Permanent Magnet, Armature, Shafts, Wheels,etc.—A Small Dynamo—Machines to Light Lamps, Run Motors, etc.—A Split-ring Dynamo—A SmallMotor—The Flat-bed Motor—Motors of Other Types
CHAPTER XI.—GALVANISM AND ELECTRO-PLATING[266]
A Fascinating Use of Electricity—A Simple Electro-plating Outfit—TheSulphate of Copper Bath—How to Make the Tank and Other Apparatus—A Variety of Beautiful and UsefulResults—Explanations of Various Batteries—The Cleansing Process—ThePlating-bath—Silver-plating—Gold-plating—Nickel-plating—Finishing—Electrotyping—PracticalDetails of Interesting Work
CHAPTER XII.—MISCELLANEOUS APPARATUS[294]
Making a Rotary Glass-cutter—To Smooth Glass Edges—Cutting Holes inGlass—Anti-hum Device for Metallic Lines—A Reel-car for Wire—Insulators—Joints andSplices—“Grounds”—The Edison Roach-killer—An Electric Mouse-killer
CHAPTER XIII.—FRICTIONAL ELECTRICITY[312]
Its Nature—Limited Uses—Simplicity of Apparatus—A “WimshurstInfluence Machine”—Materials Required—Glass, Tin-foil, Spindles, Uprights, Wheels, etc.—A LargeLeyden-jar—Apparatus for Interesting Experiments—Necessity of Caution
CHAPTER XIV.—FORMULÆ[327]
Acid-proof Cements—Hard Cement—Soft Cement—Very HardCement—Clark’s Compound—Battery Fluid—Glass Rubbing—AceticGlue—Insulators—Non-conductors—Insulating Varnish—Battery Wax
CHAPTER XV.—ELECTRIC LIGHT, HEAT AND POWER[334]
(By Joseph B. Baker)
The Work of the Dynamo—The Electric Light—Uses of theArc-light—Incandescent and Other Lamps—Electric Heat—Electric Furnaces—WeldingMetals—Electric Car-heaters—Household Uses—Electric Power—Power fromWater-wheels—Transformers—Rotary Converters—Oil-switches—Electric Traction—TheTrolley-car—The Continuous-current Motor—The Controller—Electric Locomotives—Other Forms of ElectricTraction
A DICTIONARY OF ELECTRICAL TERMS[359]