£ 00 sir ROBERT barker’s Account of 
fitting of the feveral parts, in the neceffary and fufficient 
fupports to the very large ftones that compofed them, 
and in the joining and fattening each into the other by 
means of lead and iron. 
The fituation of the two large quadrants of the m- 
ftrument marked a in the fir ft plate, whofe radius is 
nine feet two inches, by their being at right angles with 
a gnomon at twenty-five degrees elevation, are thrown 
into fuch an oblique fituation as to render them the moft 
difficult, not only to conftru<5t of fuch a magnitude, but to 
fecure in their pofition for fo long a period, and affords a 
ftriking inftance of the ability of the architect in then 
conftruftion; for, by the fhadow of the gnomon thrown 
on the quadrants, they do not appear to have altered in 
the leaft from their original pofition; and fo true is the 
line of the gnomon, that, by applying the eye to a fmall 
iron ring of an inch diameter at one end, the fight is 
carried through three others of the fame dimenfion to 
the extremity at the other end, diftant thirty-eight feet 
eight inches, without obftrutfion; fuch is the firmnefs 
and art with which this inftrument has been executed. 
This performance is the more wonderful and extraor- 
dinary when compared with the works of the artificers of 
Hindoftan at this day, who are not under the immediate 
direction 
