The Apparatus Used
17
of the Leyden jar; the smaller the capacity, the greater the frequency.
The oscillatory discharge of the Leyden jar was first noticed by Prof. Joseph Henry in 1842. Von Helmholtz in 1847 said: “We assume that the discharge of a Leyden jar is not a simple motion of the electricity in one direction, but a back-and-forward motion between the coat-
Fig. 5.—Battery of Leyden Jars.
ings in oscillation, which becomes continually smaller until the entire vis viva is destroyed by the sum of the resistances.” In 1853 Lord Kelvin proved the oscillatory discharge mathematically, and in 1859 Feddersen demonstrated it experimentally, by employing a rapidly revolving mirror.
