640 Mr. nairne’s Account of 
tend to fay; but fome of the following experiments will 
fhew that the pear-gage ftill continued in many cafes to 
indicate a lefs degree of exhauftion than the barometer- 
gage. 
In all the preceding experiments the pump was 
worked for ten minutes, and the pear-gage was at the 
end of that time pufhed down fo as for the mouth to be 
immerfed in the ciftern of quickfilver, and the air then 
let in according to the manner of uling this gage; but 
now that I found that the teftimony of this gage fo fel- 
dom agreed with that of the barometer-gage, I wifhed to 
try, whether they might not agree when the receiver was 
exhaufted only in part, though they did not when it was 
exhaufted as much as poflible. For this purpofe I had 
the fame receiver fitted with two pear-gages, fo that I 
now could immerfe the mouth of one of them in the 
ciftern of quickfilver when I had exhaufted the receiver 
in part only, and not immerge the mouth of the other 
till the receiver was exhaufted for the ufual time of ten 
minutes ; in which time I found 1 could always raife the 
quickfilver in the barometer-gage as high as if I were to 
work the pump much longer. 
EXP. 
