CAPACITY AND RESIDUAL CHARGE OP DIELECTRICS. 
113 
charge creeping above the level of the acid, and is filled with sulphuric acid to the 
shoulder; it is then placed in sulphuric acid in a glass beaker, which forms the 
inner lining of a copper vessel consisting of two concentric tubes ])etween which oil 
Fuji 
is placed, ihermometers, T^, placed in the acid outside the jar and in the oil, 
are made to register the same, or nearly the same, temperatures when taking obsei'- 
vations, hut gives the temperature taken for the flask. The flask is heated by a 
kunsen burner placed under the copper vessel. Two electi’odes a, c, insulated from 
MDCCCXCVII.—A. O 
