Memoirs presented to the Cambridge philosophical society on the occasion of the jubilee of Sir George Gabriel Stokes, bart., Hon. LL. D., Hon. SC. D., Lucasian professor.

VII. Experiments on the Oscillatory Discharge of an Air Condenser, with
a Determination of "v." By OLIVER J. LODGE, D.Sc., F.R.S.. and
R. T. GLAZEBROOK, M.A., F.R.S.
[Received 9 August, 1899.]
PART I.
GENERAL DESCRIPTION OF THE METHOD.
AFTER a considerable number of experiments on the discharge of Leyden jars, and
a qualitative study of the electric oscillations accompanying such discharge, it seemed
desirable to make an exact determination of the frequency of alternation given by a
standard condenser through a circuit of known self-induction, in order to ascertain
whether the well-known theory of the case was accurate or only an approximation.
The absolute determinations necessary were three, viz.:(1) The capacity of a condenser, which is K times a length;
(2) The self-induction of a coil, which is /u times a length; though it
would be natural to measure it indirectly by comparison with the already carefully
determined standard of electrical resistance;
(3) The period of one oscillation of the discharge, under circumstances when
the damping influences are not appreciably disturbing.
The resistance of the circuit might possibly enter as a correction into the result,
and many other minor determinations might have to be made, but these three are the
main quantities involved, and the relation between them is
T= 27r (1. K.),
and the formula would be verified if the resulting value for the product of the as yet
entirely unknown constants, t the permeability and K the inductive capacity of the
medium, agreed at all closely with the already otherwise determined value, viz. the
square of the reciprocal of the velocity of light.
It was hoped indeed that the method might turn out sufficiently accurate to give
a useful re-determination of this important quantity. It was with this idea in mind