858 Mr. nairne’s Experiments toftevo the 
from my artificial cloud, that then the longeft fpark that 
I could get to a point was one inch and one tenth ; but 
to a three tenth ball it ftruck eight inches and feven 
tenths : and what further confirmed me in my opinion 
was, that when I placed a brafs cone, half an inch at the 
bafe and two inches high, on my artificial cloud, to carry 
off part of its electricity, in order to prevent its being 
charged to high, every thing elfe being the fame, that then 
I could get a ftroke to the point one inch and one tenth as 
before, and fometimes not longer to a three tenth ball ; 
but to a one inch and three tenth ball the diftance was 
lefs, being not more than half an inch. But when I 
made no other difference than taking off the cone from 
the artificial cloud, it then ftruck to the point as before, 
viz. one inch and one tenth, and to the three tenth ball 
eight inches and feven tenths ; but to the one inch and 
three tenth ball nine inches and one tenth, inftead of 
only half an inch, as it did when the cone was on, and 
of confequcnce the conductor not fo highly charged. If 
the fubftitute was placed in contaCl with the artificial 
cloud, then there was no diftance at which it would 
ftrike to the point, but only to the balls, as Mr. wilson 
obferves was the cafe with his apparatus. His words are,, 
p. 1 1 . “ So that bringing the two fubftitutes into con- 
u taC't occafions the fame phenomena that the great cy- 
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