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lead, which will remain in the earth many cen- 
turies without any confiderable decay ; and the 
tops of chimneys being covered with it C d \ and fur- 
nifhed with a long, tharp- pointed rod of copper, 
or iron pointed with copper, which I think fhould 
extend at lead: five, or fix feet, above the top 
of the chimney, ot higheft part of the build- 
ing ; a communication fhould be made from it 
by plates of lead, eight, or ten inches broad, with 
the lead, on the ridges, and gutters, and with the 
pipes which carry down the rain-water; which 
pipes fhould be continued to the bottom of the 
building, and there made to communicate, by 
means of other leaden pipe, or a plate of it, as 
before-mentioned, with the water in a well, the 
moift earth, or the main pipe which ferves the 
houfe with water. 
SECTION FOURTH, 
Defcription and Ufe of a new prime- conductor. Con- 
trived by Mr. henly, and executed by Mr. Edward 
nairne. 
A. tab. xiv. fig. 7. A glafs-tube, eighteen 
inches long, and near two inches in dia- 
meter. 
B. C. Balls of Brafs, with a ferule, two inches 
long, to each of them ; which ferules are 
to be cemented to the ends of the tube, 
and made air-tight. 
( d ) I mention covering the tops of chimneys with lead, as a 
protection to the upper courfes of bricks, from the effeCts of 
wind ; and not as being of any eflential fervice to the conductor, 
any farther than as it may affift in fixing the pointed rod, which 
is to be elevated above it, more fecurely. 
F f f 2 One 
