Mr . cavendish on the Torpedo. 219 
of the fame ftrength as that of the leathern torpedo, and 
which I am inclined to think, from my converfation with 
Mr. walsh, may be confidered as about the medium 
ftrength of thofe of a real one of the fame fize as this. 
It was nearly equal to that of the plate of crown glafs 
in p. 206. electrified to fuch a degree as to difeharge it- 
felf when the knobs of a lane’s electrometer were at 
,0115 inches diftance; whence a perfon, ufed to electri- 
cal experiments, may afeertain its ftrength. The way I 
tried it was by holding the lane’s electrometer in one 
hand, with the end retting on the upper furface of the 
plate, and touching the lower furface with the other 
hand, while an afliftant charged the plate by its upper 
fide till it difeharged itfelf through the electrometer 
and my body. There is, however, a very fenfible dif- 
ference between the fenfation excited by a fmall jar or 
plate of glafs like this, and by a large battery electrified 
fo weakly that the fhock fhall be of the fame ftrength; 
the former being fharper and more difagreeable. Mr. 
walsh took notice of this difference; and faid, that the 
artificial torpedo produced juft the fame fenfation as the 
real one. 
As it appeared, that a fhock of this ftrength would 
pafs through a few intervals of the links of the chain, I 
tried what a fmaller would do. If the battery w r as charged 
only to a fourth or fifth part of its ufual height, the 
fhock would not pafs through a fingle interval ; but then 
it was very w eak, even when received through a piece of 
brafs wire, without any link in it. This chain v r as quite 
clean and very little tarnifhed ; the low r eft link was larger 
F f 2 than 
