in EleSir icily. 673 
fo foon as hares skin, it might, perhaps, be found better 
to fubftitute them for hares skin. 
,1 have alio excited a very confiderable electrical force 
on ftrong filk velvet, tied upon the circumference of two 
wooden disks, two feet in diameter, and diftant about 
three feet from one another, fixed upon a wooden axis. 
The velvet was fupported by a ftrong filk cloth tied un- 
der it, in order to give it more ftrength and fteadinefs. 
This machine had the appearance of a drum, and was 
whirled round, as is ufually done with glafs cylinders. 
The rubber was a cufhion covered with hares skin. 
As filk cloth, and more particularly oiled filk, very 
eafily receives a ftrong electricity, I make no doubt but a 
good ufe might be made of them, by expofing a great 
furface of them (which may be as large as one pleafes) to 
friction. I have attempted more than one method of 
conftruCting fuch a machine; but as I tried it only in 
fmall, I have not purfued the objeCt far enough, and 
therefore, I think, I have no right to throw out hints 
unfupported by experience. 
