from the Report of the Committee , 8cc. 82 1 
I muft at the fame time obferve, that, in ftating the 
different circumftances in which lightning may he col- 
lected fo as to affeCt a building, I have fuppofed a cafe 
which poffibly may never exift. I have faid, that lightning 
may accumulate direCtly over a building, and admitted, 
that in that cafe the cloud might be drained of it by a 
pointed conductor. Now we have no evidence, that the 
accumulation of lightning is confined to a fingle cloud, 
or fmall circumfcribed fpot in the heavens. On the con- 
trary, the numerous explofions, which in molt thunder 
Itorms happen nearly at one and the fame inftant, rather 
lead us to imagine that a great part of the horizon is at 
thofe times full of lightning, and therefore incapable of 
being drained. I would therefore wilh to have my fup- 
pofition underftood as a mere imaginary fuppofition, for 
the fake of rendering the argument more perfpicuous, 
and not as the admiflion of a real faCt. 
Laftly, I beg leave to correCt an expreffion I have ufed 
with refpeCt to pointed conductors, that they only ope- 
rate where their operation is not wanted. Now this is 
not accurately true : for if by operating upon a quantity 
of electricity too fmall in itfelf to do mifchief, they pre- 
vent its growing to a great and dangerous quantity, this 
would, as far as it goes, be a very confiderable advantage. 
I ought 
