C 42 ] 
VIII. A Report of the Committee appointed 
by the Royal Society, to confider of a Me- 
thod for fecurmg the Powder Magazmes 
at Purfleet. 
To the President and Members of the 
Royal Society. 
Gentlemen, 
T H E Society being confulted by the Board of 
Ordnance, on the propriety of fixing con- 
ductors for fecuring the powder magazines at Pur- 
fleet from lightning, and having thereupon done us 
the honour of appointing us a committee, to confi- 
der the fame, and report our opinion j we have ac- 
cordingly vifited thofe buildings, and examined, with 
care and attention, their fituation, conflrudtion, and 
circumfiances, which we find as follows. 
They are five in number, each about 160 feet 
long, and about 52 feet wide, built of brick, arched 
under the roof, which in one of them is dated, with 
a coping of lead 22 inches wide on the ridge from 
end to end $ and the others, as we were informed, 
are 
