[ 427 ] 
and kites being frequently raifed, to the great- 
eft heights poflible, together with a thermome- 
ter in different ftates of the weather, would 
probably foon throw new light upon this fubjedt, 
and perhaps produce difcoveries, of which we 
now have not theleaft idea. From my experiments, 
and obfervations, on the electricity of fogs ; I once 
imagined, that, whenever I faw a very thick one, 
and the air was at the fame time (harp, and frofty ; 
that fog, was ftrongly eledtrified pofitively: but I 
have met with feveral exceptions to this rule, for on 
Dec. 24, 25, 26, 27, 28, 29, 1772, in all which 
days there were thick fogs, thermometer from 36 
to 33, wind conftantly N. E. I could perceive no 
fenfible eledtricity. Hence I conjedlured,that though 
1 could difcover none in my fituation , yet higher in 
the atmofphere it might probably be found in plen- 
ty, and this conjedture was prefently afterward 
verified by Mr. nairne, who obferved the air to 
be eledtrical, when he flood in the golden gallery of 
St. Paul’s cathedral, which is about two hundred 
and eighty feet in height, though he could difcover 
none in the ftone gallery, which is confiderably 
lower: and the fame obfervation hath ftnce been 
made by others ; and by myfelf, when I found 
the divergence of the balls to be incrcafed, if I 
projedled the rod, (from which they were 
fufpended) through one of the lights, in the 
lanthorn ; which is ftill higher. And it is 
with fome pleafure that I have fince obferved 
that Dr. lind, and Mr. brydone, have made the 
( 0 ) If Lord Charles cavendish’s can be raifed properly, 
perhaps that may be preferable to any other. 
I i i 2 fame 
