lectricity. The
Condenser. Connecting up a Condenser. The Interrupter. Uses of
High-tension Coils.

XI. WIRELESS TELEGRAPHY Page 104

Telegraphing Without Wires. Surging Character of High-tension
Currents. The Coherer. How Made. The Decoherer. The Sending Apparatus.
The Receiving Apparatus. How the Circuits are Formed.

XII. THE TELEPHONE Page 110

Vibrations. The Acoustic Telephone. Sound Waves. Hearing Electricity.
The Diaphragm in a Magnetic Field. A Simple Telephone Circuit. How to
Make a Telephone. Telephone Connections. Complete Installation. The
Microphone. Light Contact Points. How to Make a Microphone.
Microphone, the Father of the Transmitter. Automatic Cut-outs for
Telephones. Complete Circuiting with Transmitters.

XIII. ELECTROLYSIS, WATER PURIFICATION, ELECTROPLATING Page 123

Decomposing Liquids. Making Hydrogen and Oxygen. Purifying Water.
Rust. Oxygen as a Purifier. Composition of Water. Common Air Not a
Good Purifier. Pure Oxygen a Water Purifier. The Use of Hydrogen in
Purification. Aluminum Electrodes. Electric Hand Purifier.
Purification and Separation of Metals. Electroplating. Plating Iron
with Copper. Direction of Current.

XIV. ELECTRIC HEATING. THERMO-ELECTRICITY Page 135

Generating Heat in a Wire. Resistance of Substances. Signs of
Connectors. Comparison of Metals. A Simple Electric Heater. How to
Arrange for Quantity of Current Used. An Electric Iron.
Thermo-Electricity Converting Heat Directly into Electricity Metals.
Electric, Positive, Negative. Thermo-electric Coupler.

XV. ALTERNATING CURRENTS, CHOKING COIL, TRANSFORMER Page 145

Direct Current. Alternating Current. The Magnetic Field. Action of a
Magnetized Wire. The Movement of a Current in a Charged Wire. Current
Reversing Itself. Self-Induction. Brushes in a Direct Current Dynamo:
Alternating, Positive and Negative Poles. How an Alternating Current
Dynamo is Made. The Windings. The Armature Wires. Choking Coils. The
Transformer. How the Voltage is Determined. Voltage and Amperage in
Transformers.

XVI. ELECTRIC LIGHTING Page 161

Early conditions. Fuels. Reversibility of Dynamo. Electric arc.
Mechanism to maintain the arc. Resistance coil. Parallel carbons for
making arc. Series current. Incandescent system. Multiple circu