162 ESSAYS anp OBSERVATIONS | 
fome other fluids to be mentioned by and 
by, I have produced a finking of the ther- 
mometer much more confiderable. 
In making experiments of this kind, it 
is to be obferved, that the cold produced is 
of very fhort duration. On this account 
it is not proper to employ a thermometer 
inclofed in a glafs tube; and itis neceflary 
to employ one having a fmall ball, which 
may render it more fenfible- But, asa 
fmall ball occafiens the divifions of the 
{cale to be the fmaller, a thermometer fil- 
led with quick filver is not fo proper for 
thefe experiments, as one filled with fpirit 
of wine; having at the fame time both a 
fmall ball and a flender ftem. What beft 
of all fhews the cold produced, and is in- 
deed, with refpeé to feveral fluids, quite 
neceflary, is an air thermometer. This 
too will be rendered more convenient by 
having the upper part of the 
tube bent as in the figure an- 
nexed, fo that the ball may | 
be moiftened without the li- | 
quor’s running down upon 
the {tem and {cale. 
