Jtnall Quantities of Electricity. 1 1 
back of the plate. The plate itfelf is of ftrong tin, and mea- 
fures about eight inches in diameter. The {land AB projects 
very little before the plate, by which means, when two of 
thole plates are placed upon a table facing each other, the 
wooden {lands will prevent their coming into aCtual contact, as 
may be clearly perceived in fig. 3. 
I need not deferibe the manner of doubling or of multiply- 
ing with thofe plates; the operation being eflcntially the fame 
as when the plates are conftruCted according to Mr. Bennkt’s 
original plan, excepting that, inftead of placing them one 
upon the other, mine are placed facing each other; and in 
performing the operation they are laid hold of by the wooden 
{land AB ; lb that no friction can take place either upon the 
glafs legs, or upon any varnifh ; for thefe plates have no need 
of being varnifhed. Sometimes, inftead of touching the plates 
themfelves with the finger, I have fixed a piece of thin wire to 
the back of the plate, and have then applied the finger to the 
extremity of the wire, fufpeCting that fome friction and fome 
electricity might pofiibly be produced when the finger was 
applied in full contact to the plate itfelf. 
It is evident, that as the plates do not come fo near to each 
other in this, as they do in the other conftruCtion, the electri- 
city of one of them cannot produce fo great a quantity of the 
contrary electricity in the oppofite plate ; hence, in this con- 
ftruCtion, it will be neceflary to continue the operation of 
doubling fomewhat longer; but this difadvantage is more than 
repaid by the certainty of avoiding any friction. 
Having conftru&ed thofe plates, I thought that I might pro- 
ceed to perform the intended experiments without any further 
cbftruCtion ; but in this I found myfelf quite miftaken : for, 
oji trying to multiply with thofe new plates, and when no 
C 2 eleCtricity 
