Mr. swift’s Account , See. 455 
portion as it is increafed in the prime conductor in the 
fame time. 
Another thing peculiar to this machine is, that the 
whole is infulated, fo that being able to collect the elec- 
tric matter without any connexion with the earth, and 
having at the fame time bodies or conductors poiitively 
and negatively electrified, I apprehend I am enabled by 
this apparatus to exhibit many experiments more analo- 
gous to the natural effects of lightning from the clouds, 
than it is poflible to do with only one conductor poiitively 
electrified ; becaufe in nature clouds are conflantly flying 
in the air which are differently electrified, and, difeharg- 
ing themfelves in each other, produce the lightning often 
feen in the atmofphere. 
I have annexed a flight Iketch of the apparatus : a is 
the glafs cylinder ; b the prime conductor, on two glafs 
Items ; c the anti-conductor, on two glafs Items, con- 
nected with the cufhion of the machine; dd is a pole or 
round ftaff, well covered with metal, with a ball at each 
end, which hangs over the two conductors b and c; this 
ftaff is fattened to the crofs pole/, which is fufpended by 
a filk line in fuch a manner that the ftaff dd is equally 
balanced. 
It may be proper to mention a few' common experi- 
ments and obfervations, to fhew, that the two conductors 
O o o 2 
are 
