t 3 s 3 
V. Appendix to the Defcription of a new Electrometer. In & 
Letter from the Rev . Abraham Bennet, M. A. to Charles 
Blagden, M. D. Sec. R . S. 
HE following defcription of my Electrometer, connected 
with M. Volta’s Condenfer, waits on the approbation 
of the Royal Society, to be inferted in the Philofophical Tran- 
sactions, as an Appendix to my Paper, communicated by Dr. 
Priestley. 
The metallic cap of the electrometer is for this purpofe to 
be ground and polifhed flat and fmooth, to fit a piece of marble 
alfo polifhed on both fides, and varnifhed. In the fide of the 
marble is to be fixed a glafs or baked-wood handle. Laftly, on 
the top is a fmaller metallic plate, furnifhed alfo with an in- 
fulating handle. The whole conftruCtion will be underftood by 
the annexed drawing (fee Table III. fig. 2.). When a fmall 
charge of eleCtricity is communicated to the metal at A, whilfl 
the marble B is touched, the Angle condenfer is charged, and its 
eleCtricity (if in fufficient quantity) will be fenfible when the 
marble is lifted up by the handle C ; but, if not now fenfible, 
touch the fmall plate D, whilfl: thus lifted up ffom the cap, and 
then lift it off the marble by its infulating handle, and pre- 
Read December 21, 1786. 
s I a, 
Wirkfworth, Dec. 18, 17S6. 
