Advantage of elevated pointed Conductors. 857 
ftrike as far to the three tenth ball as the point; but in 
my experiments I have had it ftrike ten inches three 
tenths to a point, and ten inches and eight tenths to a 
three tenth ball; but to a one inch and three tenths ball 
it commonly ftruck to fifteen inches, and fometimes to 
fixteen inches. In anfwer to the eighteenth and following 
experiments I mult obferve, that the fubftitute being- 
fixed is unnatural; for clouds are compofed of a fluid 
matter, moving with the utmoft facility in another fluid 
fubftance; and from my twenty-third experiment, where 
the fubftitute was fixed, the point was ftruck; yet in the 
twenty-fourth experiment, where there was no other 
alteration than, allowing the cloud to move freely, then 
the point was not ftruck. I imagine, if Mr. wixson’s 
large artificial cloud at the Pantheon, which was 155 
feet long and 16 in diameter, had been properly infu- 
lated, and there had been feveral cylinders properly 
mounted to have charged it, he would have found the 
ftriking diftance, and every other of his experiments, 
very different from what he did, particularly thofe where 
his fubftitute was fixed about one inch and a half from 
his large artificial cloud. 
My reafons for thus thinking are, that when I placed 
a fubftitute of exactly the fame dimenfions in every re- 
fpe£t as his, and placed it alfo about one inch and a half 
Vo l. LX VIII. 5O from 
