asure rather than a task. We find,
therefore, that in 1912, "self-starters" began to be used. These were
not all electrical, some used tanks of compressed air, others
acetylene, and various mechanical devices, such as the spring
starters. The electrical starters, however, proved their superiority
immediately, and filled such a long felt want that all the various
makes of automobiles now have electric starters. The present day motor
car, therefore, uses gasoline for the engine only, but uses
electricity for ignition, starting, lighting, for the horn, cigar
lighters, hand warmers on the steering wheel, gasoline vaporizers, and
even for shifting speed changing gears, and for the brakes.

On any car that uses an electric lighting and starting system, there
are two sources of electricity, the generator and the battery, These
must furnish the power for the starting, or "cranking" motor, the
ignition, the lights, the horn, and the other devices. The demands
made upon the generator are comparatively light and simple, and no
severe work is done by it. The battery, on the other hand is called
upon to give a much more severe service, that of furnishing the power
to crank the engine. It must also perform all the duties of the
generator when the engine is not running, since a generator must be in
motion in order to produce electricity.

A generator is made of iron, copper, carbon, and insulation. These are
all solid substances which can easily be built in any size or shape,
and which undergo very little change as parts of the generator. The
battery is made mainly of lead, lead compounds, water and sulphuric
acid. Here we have liquids as well as solids, which produce
electricity by changes in their composition, resulting in complicated
chemical as well as electrical actions.

[Fig. 1 The Battery]

The battery is, because of its construction and performance, a much
abused, neglected piece of apparatus which is but partly understood,
even by many electrical experts, for to understand it thoroughly
requires a study of chemistry as well as of electricity. Knowledge of
the construction and action of a storage battery is not enough to make
anyone an expert battery man. He must also know how to regulate the
operating conditions so as to obtain the best service from the
battery, and he must be able to make complete repairs on any battery
no matter what its condition may be.

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