[ 20 5 ] 
oned. I would recommend likewife an increafe of 
their number j as the effects of one apparatus of this 
kind can extend only to a certain diftance, and that 
to no great one ; and the fecurity, where mifchiefs 
from lightning are frequent, mufc arife from their 
number. In countries and places fo circumftanced, 
no houfe or other building fhould be without one at 
leaft j large edifices ought to have feverah The 
number fhould be in proportion to the fize of the 
building. 
III. In powder magazines, I fhould recommend the 
apparatus to be detached from the building itfelf ; 
and to be only placed as near it as might be. Pow- 
der magazines fhould never be conftru&ed fo, as to 
cover a large quantity of ground. If fecurity from 
lightning was confidered in their conftru&ion as a 
confiderable objedt, I fhould recommend a circular 
building ; in the periphery of which fhould be placed 
ftorehoufes fufficient in their number and extent to 
contain the quantity of powder propofed. In the 
centre of this circle fhould be a well, very near which 
fhould be eredled a pole or maft, high enough to reach 
fome feet above the buildings of the powder maga- 
zine, or the buildings in it’s neighbourhood. From 
this maft there fhould rife a brafs rod, five or fix feet 
in length, an inch in thicknefs, and ending in a 
point ; and from this rod a wire of copper of a fize 
not lefs than that of a large goofe quill, fhould be con- 
veyed down the maft, and terminate in the water of 
the well. If there is no well, the wire fhould be 
laid into the neareft water ; as the expence even of 
fome hundred yards of a wire of this fort can hardly 
be confidered as an object in an affair of this impor- 
tance. 
