same period. In
1705 Hawksbee made numerous experiments; also Gray, in 1720, and a
Welshman, Dufay, at about the same time. The Germans, from 1740 to 1780,
made many experiments. In 1740, at Leyden, was discovered the jar which
bears that name. Before that time, all experiments began and ended with
frictional electricity.

The first attempt to "bottle" electricity was attempted by
Muschenbr[oe]ck, at Leyden, who conceived the idea that electricity in
materials might be retained by surrounding them with bodies which did
not conduct the current. He electrified some water in a jar, and
communication having been established between the water and the prime
conductor, his assistant, who was holding the bottle, on trying to
disengage the communicating wire, received a sudden shock.

In 1747 Sir William Watson fired gunpowder by an electric spark, and,
later on, a party from the Royal Society, in conjunction with Watson,
conducted a series of experiments to determine the velocity of the
electric fluid, as it was then termed.

Benjamin Franklin, in 1750, showed that lightning was electricity, and
later on made his interesting experiments with the kite and the key.

DISCOVERING GALVANIC ELECTRICITY.--The great discovery of Galvani, in
1790, led to the recognition of a new element in electricity, called
galvanic or voltaic (named after the experimenter, Volta), and now known
to be identical with frictional electricity. In 1805 Poisson was the
first to analyze electricity; and when [OE]rsted of Copenhagen, in 1820,
discovered the magnetic action of electricity, it offered a great
stimulus to the science, and paved the way for investigation in a new
direction. Ampere was the first to develop the idea that a motor or a
dynamo could be made operative by means of the electro-magnetic current;
and Faraday, about 1830, discovered electro-magnetic rotation.

ELECTRO-MAGNETIC FORCE.--From this time on the knowledge of electricity
grew with amazing rapidity. Ohm's definition of electro-motive force,
current strength and resistance eventuated into Ohm's law. Thomson
greatly simplified the galvanometer, and Wheatstone invented the
rheostat, a means of measuring resistance, about 1850. Then primary
batteries were brought forward by Daniels, Grove, Bunsen and Thomson,
and electrolysis by Faraday. Then came the instruments of precision--the
electrometer, the resistance bridge, the ammeter, the voltmeter--all of
the utmost value in the scien