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tance. For though I have reafoa to believe, that the 
wire communicating with the ground would prevent 
the mifchiefs of a thunder cloud, which came near 
an apparatus of this fort ; yet as water is a more ready 
conductor than the ground, it fhould, if pofhble, be 
infilled upon in this particular cafe, and employed. Mr. 
Weft’s apparatus, defcribed by the before-mentioned 
Mr. Kinnerfley, terminated in an iron ftake, driven four 
or five feet into the ground ; neverthelefs the earth did 
not condud the lightning fo faft but that, in a thunder 
ftorm, the lightning was feen to be diffufed near the 
ftake two or three yards over the pavement, though at 
that time very wet with rain. It is prefumed, that had 
this iron ftake been placed in water inftead of earth, 
the lightning had not been vilible, on account of the 
water’s receiving the eledric matter more readily than 
earth. Where this apparatus therefore is applied to 
powder magazines, it fliould certainly terminate in 
water. At Mr. Hamilton's at Cobham, about twenty 
miles from hence, where an apparatus of this fort 
was ereded upon an high and greatly- expofed build- 
ing, as there was no water but at a great diftance, 
the bottom of the wire was placed deep in an hill 
of inoift fand. If, inftead of one wire, two, three, 
or more, were adapted to the brafs rod in this man- 
ner, and conduded to the water, or if the brafs rod 
itfelf was continued to the water, I ftiould confider 
it, in extraordinary cafes, as an additional fecurity. 
This will explain my fentiments upon the third, 
fourth, and fixth queftions. 
V. As the expectation of the utility of this appa- 
ratus is prefumed to be the preventing of the accumu- 
lation of eledricity in its neighbourhood, by afford- 
i ing 
