*oS Mr. cavendish’s Obfervations 
Boiling point. Freezing point, 
220.3 • 29,9 
2l8,8 - 30,9 
215.3 - 32 
The boiling point was tried in the manner recommended in 
the report of the Committee of the Royal Society, printed in 
the Philofophical Tranfa&ions for the year 1777, anc * allowance 
made, as there directed, for the height of the barometer at that 
time. In fixing the freezing point alfo allowance was made for 
the temperature of the room in which it was tried. 
The great difference in the polition of the boiling point on 
thefe thermometers leems owing only to care not hav ing been 
taken to keep the quick frlver in the tube of the fame heat as 
that in the ball, which is a circumftance that was very little 
attended to when they were made ; and I am afraid is not fo 
much obferved at prefent as it ought to be, and which in A 
and B, whofe tubes contained upwards of 900° of quickfilver, 
caufed an exceflively great error, and much more than it did in 
G, which contained fewer degrees in its tube. 
In order to fee whether the inequalities of the bore of the 
tube were properly allowed for, a column of quickfilver, about 
100 long, was feparated from the reft ; and it was examined, 
whether its length comprehended the fame number of degrees 
on the fcale in different parts of the tube ; when no fenfible 
error could be found in this refpedt in G, and none worth re- 
garding in B. The thermometer A, by reafon of its being 
conftrudted with a bulb tilled with air at top, could not be exa- 
mined in this manner ; but there is no reafon to think, that it 
was faulty in this refpedt. 
A 
B 
G 
From 
