[ 5 2 5 ] 
taken in the drawing. 7 , the penumbra. K , K , 
the Aiders. L, L, L, L, pullies, over which the 
line runs, that moves the penumbra. M, the han- 
dle, to which both ends of the line are Axed. N, 
a collar on the axis of the handle. O, O, the 
fights on the pedeftal. 
LX VIII. A Letter from the Reverend Henry 
Miles, D. D. F. R. R. to Mr. John 
Canton, F. R. R. concerning the late hard 
hF lather . 
D ear Sir , 
Read Feb. aSj'y Thank you for your account of the 
/5+ JL Aate of your thermometer, on the 
days moft remarkable for cold this leafon ; and, in 
a paper inclofed, have fent you the regifter I made of 
my thermometer (fee p. 527.), on the fame days, ac- 
cording to your deiire wh^ph, if you pleafe, you may 
lay before the Royal Society, with the few following 
remarks : 
You tell me, you have never before obferved fo 
great a degree of cold ; nor have I, for feverai years 
before you began to make your obfervations, or fince 
you did. It was in the year 1740. when I, occafion- 
ally, hung a mercurial thermometer abroad ; and in 
February, the following year, -conftantly. Not having 
heard, that any one had ufed to do fo, I was led to it > 
by a very fenfible warmth in the air, which I per- 
ceived upon accidentally looking out at my window, 
a good while before day : So that I cannot undertake 
to 
