738 Col. roy’s Experiments for 
it in any other light) ftill exifts. Thus, in the coldeft of 
the morning, as well as in the ordinary obfervations, when 
the temperature is at or near freezing, the mean ratio of 
the weight of quickfilver to air, is about 10850 to 1. 
When the obferved and reduced temperatures are re- 
fpeftively 41 0 and 3 5 °, the ratio between them is that 
of 1 1 295 to 1, anfwering nearly to what hath been af- 
figned to them when the heat is 69°. 3 2. Again, 
in the hotteffc obfervations of the 14th and 15th of 
July 1759, an d 20th of July 1760, on the higheft, 
and confequently the bell ftations, when the obferved 
and reduced temperatures are refpeftively 8 i°. 7 and 
7 5°. 6, quickfilver is to air as 12650 to 1. Now if we 
reduce this number 1 2 6 5 o by a proportionable part, for 
the degrees of difference between Mr. de luc’s zero 
6 9 0 . 3 2, and the obferved and reduced temperatures re- 
fpeftively, we fhall have, in the firft cafe, 12200; and 
in the laft, 1-2390 to 1, for the ratio of the weight of 
quickfilver to air; either of which exceeds very confi- 
derably 11232, which hath been affigned to them. 
With regard to the obfervations on the Dole, the de- 
left is anfwering to the obferved temperature of' 
66°. 6, and which is only reduced to 65°. 2. On this 
great height, the ratio of the weight of quickfilver to 
