of investigation, had not, after all, left much of a legacy in either
principles or appliances. The lodestone and the compass; the frictional
machine; the Leyden jar; the nature of conductors and insulators;
the identity of electricity and the thunder-storm flash; the use of
lightning-rods; the physiological effects of an electrical shock--these
constituted the bulk of the bequest to which philosophers were the only
heirs. Pregnant with possibilities were many of the observations that
had been recorded. But these few appliances made up the meagre kit
of tools with which the nineteenth century entered upon its task of
acquiring the arts and conveniences now such an intimate part of "human
nature's daily food" that the average American to-day pays more for his
electrical service than he does for bread.

With the first year of the new century came Volta's invention of the
chemical battery as a means of producing electricity. A well-known
Italian picture represents Volta exhibiting his apparatus before the
young conqueror Napoleon, then ravishing from the Peninsula its treasure
of ancient art and founding an ephemeral empire. At such a moment this
gift of despoiled Italy to the world was a noble revenge, setting in
motion incalculable beneficent forces and agencies. 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