es. For the first
time man had command of a steady supply of electricity without toil or
effort. The useful results obtainable previously from the current of a
frictional machine were not much greater than those to be derived from
the flight of a rocket. While the frictional appliance is still
employed in medicine, it ranks with the flint axe and the tinder-box
in industrial obsolescence. No art or trade could be founded on it; no
diminution of daily work or increase of daily comfort could be secured
with it. But the little battery with its metal plates in a weak
solution proved a perennial reservoir of electrical energy, safe and
controllable, from which supplies could be drawn at will. That which was
wild had become domesticated; regular crops took the place of haphazard
gleanings from brake or prairie; the possibility of electrical
starvation was forever left behind.

Immediately new processes of inestimable value revealed themselves; new
methods were suggested. Almost all the electrical arts now employed
made their beginnings in the next twenty-five years, and while the more
extensive of them depend to-day on the dynamo for electrical energy,
some of the most important still remain in loyal allegiance to the older
source. The battery itself soon underwent modifications, and new types
were evolved--the storage, the double-fluid, and the dry. Various
analogies next pointed to the use of heat, and the thermoelectric cell
emerged, embodying the application of flame to the junction of two
different metals. Davy, of the safety-lamp, threw a volume of current
across the gap between two sticks of charcoal, and the voltaic arc,
forerunner of electric lighting, shed its bright beams upon a dazzled
world. The decomposition of water by electrolytic action was recognized
and made the basis of communicating at a distance even before the days
of the electromagnet. The ties that bind electricity and magnetism in
twinship of relation and interaction were detected, and Faraday's work
in induction gave the world at once the dynamo and the motor. "Hitch
your wagon to a star," said Emerson. To all the coal-fields and all the
waterfalls Faraday had directly hitched the wheels of industry. Not
only was it now possible to convert mechanical energy into electricity
cheaply and in illimitable quantities, but electricity at once showed
its ubiquitous availability as a motive power. Boats were propelled by
it, cars were hauled, and even papers