i -g Mr. smeathman’s Account of 
The interior building or afiemblage of nurferies, chambers, 
&c. has a flattifh top or roof without any perforation, which 
would keep the apartments below dry, in cafe through accident 
the dome fhould receive, any injury and let in water ; and it is 
never exadily flat and uniform, becaufe they are always adding 
to it by building more chambers and nurferies : fo that the 
divifions or columns between the future arched apartments ' re- 
ferable the pinnacles upon the fronts of fome old buildings, , 
and demand particular notice as affording one proof that for the 
mod part the infects projedt their arches, and do not make them, . 
as I imagined for a long time, by excavation (tab. VII. fig. 2. b.). 
The area has alfo a flattifh floor, which lays over the royal- 
chamber, but fometimes a good height above it, having nurfe- 
ries and magazines between (tab. VII. fig. 2. c*)» Itis like wife 
water-proof, and contrived, as far as 1 could guefs, to let the 
water off, if it fhould get in, and run over by fome fhort way. 
into the fubterraneous paffages which run under the loweft ap- 
artments in the hill in various directions, and are of an aftonifh- 
ing fize, being wider than the bore of a great cannon. I have a 
memorandum of one I meafured, perfectly cylindrical, and 
thirteen inches in diameter (tab. VII. fig. 2. d. d.)> 
Thefe fubterraneous paffages or galleries are lined very thick 
with the fame kind of clay of which the hill is compofed, and 
afcend the infide of the outward fhell in a fpiral manner, and 
winding round the whole building up to the top interfedl each 
other at different heights, opening either immediately into the 
dome in various places, and into the interior building, the new I 
turrets, &c. or communicating thereto by other galleries of 
different bores or diameters, either circular or oval. 
From every part of thefe large galleries are various fmall 
pipes or galleries leading to different parts of the building. 
Under 
