Page 29

Three Electrical Sources. Frictional Electricity. Leyden Jar. Voltaic
or Galvanic Electricity. Voltaic Pile; How Made. Plus and Minus
Signs. The Common Primary Cell. Battery Resistance. Electrolyte and
Current. Electro-magnetic Electricity. Magnetic Radiation. Different
Kinds of Dynamos. Direct Current Dynamos. Simple Magnet Construction.
How to Wind. The Dynamo Fields. The Armature. Armature Windings.
Mounting the Armature. The Commutator. Commutator Brushes. Dynamo
Windings. The Field. Series-wound Field. Shunt-wound. Compound-wound.

V. HOW TO DETECT AND MEASURE ELECTRICITY Page 49

Measuring Instruments. The Detector. Direction of Current. Simple
Current Detector. How to Place the Detector. Different Ways to Measure
a Current. The Sulphuric Acid Voltameter. The Copper Voltameter. The
Galvanoscope Electro-magnetic Method. The Calorimeter. The Light
Method. The Preferred Method. How to Make a Sulphuric Acid Voltameter.
How to Make a Copper Voltameter. Objections to the Calorimeter.

VI. VOLTS, AMPERES, OHMS AND WATTS Page 60

Understanding Terms. Intensity and Quantity. Voltage.
Amperage Meaning of Watts and Kilowatt. A
Standard of Measurement. The Ampere Standard. The
Voltage Standard. The Ohm. Calculating the Voltage.

VII. PUSH BUTTONS, SWITCHES, ANNUNCIATORS, BELLS AND
LIKE APPARATUS Page 65

Simple Switches. A Two-Pole Switch. Double-Pole Switch. Sliding
Switch. Reversing Switch. Push Buttons. Electric Bells. How Made. How
Operated. Annunciators. Burglar Alarm. Wire Circuiting. Circuiting
System with Two Bells and Push Buttons. The Push Buttons, Annunciators
and Bells. Wiring Up a House.

VIII. ACCUMULATORS, STORAGE OR SECONDARY BATTERIES Page 82

Storing Up Electricity. The Accumulator. Accumulator Plates. The Grid.
The Negative Pole. Connecting Up the Plates. Charging the Cells. The
Initial Charge. The Charging Current.

IX. THE TELEGRAPH Page 90

Mechanism in Telegraph Circuit. The Sending Key. The Sounder.
Connecting Up the Key and Sounder. Two Stations in Circuit. The Double
Click. Illustrating the Dot and the Dash. The Morse Telegraph Code.
Example in Use.

X. HIGH-TENSION APPARATUS, CONDENSERS, ETC. Page 98

Induction. Low and High Tension. Elastic Property of E