running; friction clutches are used also to throw in gears of
different sizes to increase or decrease the speed of the vehicle, as
well as to drive backward.

[Illustration: AN AUTOMOBILE BUCKBOARD]

The early gasoline automobiles sounded, when moving, like an artillery
company coming full tilt down a badly paved street. The exhausted gas
coughed resoundingly, the gears groaned and shrieked loudly when
improperly lubricated, and the whole machine rattled like a runaway
tin-peddler. Ingenious mufflers have subdued the sputtering exhaust, the
gears are made to run in oil or are so carefully cut as to mesh
perfectly, rubber tires deaden the pounding of the wheels, and carefully
designed frames take up the jar.

Steam and gasoline vehicles can be used to travel long distances from
the cities, for water can be had and gasoline bought almost anywhere;
but electric automobiles, driven by the third of the three powers used
for self-propelled vehicles, must keep within easy reach of the charging
stations.

Just as the perfection of the gasoline motor spurred on the inventors to
adapt the steam-engine for use in automobiles, so the inventors of the
storage battery, which is the heart of an electric carriage, were
stirred up to make electric propulsion practical.

The storage battery of an electric vehicle is practically a tank that
holds electricity; the electrical energy of the dynamo is transformed
into chemical energy in the batteries, which in turn is changed into
electrical energy again and used to run the motors.