156 Prof. Oliver Lodge on the Seat of the 
Fig. 1.—Kohlrausch’s Early Form of Condenser. 
Both the plates are insulated by silk threads. The fixed wire, d, with 
which the raised plate comes into contact, leads to a Dellman electro- 
meter. The connections are arranged for determining the “ electro- 
scopic tension” on the poles of an open battery, to see if it is the same 
as the H.M.F. (See Poge. Ann. 1848, vol. xxv. pp. 88 and 220,) 
This apparatus he also used to measure the Volta effect between two 
metals, his classical memoir on the subject being in Poggendorff’s Annalen, 
1851, vol. Ixxxii. p. 1. Later he improved the condenser, bringing it into 
the form shown in the following figure. 
Vig. 2.—Kohlrausch’s Later Form of Condenser. 
(See Poge, Ann, 1853, vol. Ixxxviii. p. 464.) 
a as 
