s, and thus opened a new chapter in the
history of mankind.

GEORGE ILES.

CONTENTS

FRANKLIN, BENJAMIN

LIGHTNING IDENTIFIED WITH ELECTRICITY

Franklin explains the action of the Leyden phial or jar.
Suggests lightning-rods. Sends a kite into the clouds during
a thunderstorm; through the kite-string obtains a spark
of lightning which throws into divergence the loose fibres
of the string, just as an ordinary electrical discharge
would do. 3

FARADAY, MICHAEL

PREPARING THE WAY FOR THE ELECTRIC DYNAMO AND MOTOR

Notices the inductive effect in one coil when the circuit in
a concentric coil is completed or broken. Notices similar
effects when a wire bearing a current approaches another
wire or recedes from it. Rotates a galvanometer needle by
an electric pulse. Induces currents in coils when the magnetism
is varied in their iron or steel cores. Observes the lines
of magnetic force as iron filings are magnetized. A magnetic
bar moved in and out of a coil of wire excites electricity
therein,--mechanical motion is converted into electricity.
Generates a current by spinning a copper plate in a horizontal
plane. 7

HENRY, JOSEPH

INVENTION OF THE ELECTRIC TELEGRAPH

Improves the electro-magnet of Sturgeon by insulating its
wire with silk thread, and by disposing the wire in several
coils instead of one. Experiments with a large electro-magnet
excited by nine distinct coils. Uses a battery so powerful
that electro-magnets are produced one hundred times more
energetic than those of Sturgeon. Arranges a telegraphic
circuit more than a mile long and at that distance sounds
a bell by means of an electro-magnet. 23

ILES, GEORGE

THE FIRST ATLANTIC CABLES

Forerunners at New York and Dover. Gutta-percha the indispensable
insulator. Wire is used to sheathe the cables. Cyrus W.
Field's project for an Atlantic cable. The first cable fails.
1858 so does the second cable 1865. A triumph of courage,
1866. The highway smoothed for successors. Lessons of the
cable. 37

BELL, ALEXANDER GRAHAM

THE INVENTION OF THE TELEPHONE

Indebted to his father's study of the v