on Mr. hutchins’s Experiments . 309 
From what has been faid it appears, that 183', 3 on the Icale 
of G are equal to only i8o‘ on a thermometer adj lifted as re- 
commended by the Committee, and therefore 72° are equal to 
70 0 -*; fo that the point of - 40° anfwers really to - 38°^ ; 
that is, the cold fhewn by this thermometer at the tempera- 
ture of about - 40° is T4 too great. In like manner it ap- 
pears, that the cold fhewn at that temperature by B is 4%, and 
by A 64, too great. 
On the whole, thefe thermometers feem to have been care- 
fully made, their difagreement being owing only to a faulty 
manner of adjufting the boiling point, and to not allowing lor 
the temper of the air in fettling the degree ol freezing ; and as 
thefe points were examined after they came back, the experi- 
ments made with them are juft as much to be depended on as 
if they had been truly adj ufted at hrft. 
Thefe inftruments were made in the year 1776, and were 
intended to have been fent to Mr. hutchins that year, through 
the hands of the late Dr. maty, who promifed to recommend 
the experiment to him; but, by not being got reat.7 time 
enough to be lent that year, and a miftaKcn luppohtion that 
Mr. hutchins was to come back the next fummer, they were 
prevented from being fent till 1781 ; when S11 Joseph banks- 
was informed by Mr. wegg, that theie was a gentleman at 
Hudfon’s Bay who was willing to undertake any experiments 
of that kind ; and that the Hudfon’s Bay Company would be 
at the expence of any inftruments necefiaiy loi the puipole. 
Then, as Sir Joseph thought the abovementioned apparatus 
well adapted to the purpofe, 1 gladly embraced the opportunity 
of fending it. It appears, however, from the letter inferred 
bv Mr. hutchins, that Dr. black, without being acquainted 
7 with . 
