344 M\ mudge on the ConJlruBiion 
of about two-tenths of an inch long; moreover, the 
figures in the feveral lines were differently difpofed, and 
the fum of each line alfo differed. It is evident that by this 
method all guefs is precluded ; and that of twoinftruments, 
of the fame powers, that which can make out the leaft 
order of figures, which will be known by the fum, is the 
beft telefcope. Such a plate I caufed to be fixed up for 
experiments againft the top of a ft eeple, about three hun- 
dred yards North of my houfe; and it will ferve to give 
fome idea of the diftindtnefs with which very fmall figures 
could be made out at that diftance, by faying, that in a 
clear ftate of the air, and with the Sun behind me, with 
a telefcope of eighteen inches focal length, which Count 
bruhl did me the honour to accept and now has in his 
poffeflion, I have feen the legs of a fmall fly, and the 
fhadows of them, with great precifion and exadtnefs. 
I cannot conclude without indulging myfelf in an ob- 
fervation on the amazing fagacity of Sir Isaac newton 
in every fubjedt upon which he thought fit to employ 
his attention. It was he who firft propofed, and indeed 
pradtifed, the polifhing with pitch; a fubftance which at 
firft fight perhaps every one but himfelf would have 
thought very improper, from its foftnefs, to produce that 
corredtnefs of figure fo neceffary upon thefe occafions; 
and yet I do believe, that it is the only fubftance in nature 
..-a that ' 
