632 
Mr. nairne’s Account of 
EXP. xxxii. The receiver was taken off, and after the -j 
cement was wiped clean from it, and every part made I 
perfe&ly dry, it was put again on the pump-plate, J 
and a little oil only was poured round the outfide edge, J 
Exp. xxxiii. The receiver was taken off again, and in-^ 
Head of the oil it was fet on a piece of leather, l 
which had been foakcd two days in water, — J 
exp. xxxiv. The laft experiment repeated with the 1 
fame piece of leather, — — 
exp. xxxv. The laft experiment repeated again with 
the fame piece of leather, — — 
exp. xxxvi. The receiver was taken off, and inftead of 
the leather foaked in water, there was put on a piece of I 
the fame fort of leather, foaked in a mixture of water | 
and fpirit of wine, fuch as Mr. smeaton ufed, J 
iExp. xxxvii. The laft experiment repeated with the! 
fame leather, — — ; — J 
exp. xxxviii. The laft experiment repeated again with^ 
the fame leather, — — 
j 
Degrees of exhauf- 
tion according to 
Barom. 
£ a S e * 
Pear- 
gage. 
nearly 600 
full 600 
16,000 
5 l 
1500 
S l 
IOOO 
47 
12,000 
47 
1150 
47 
500 
The great difference in the teftimony of the pear-gage 
in thefe fix laft experiments appeared to me exceedingly 
aftonifhing, for the leathers feemed each of them to be 
as moift at laft as at firft. 
By thefe experiments I was convinced how effe&ually 
the ufe of leather foaked in water, or in water and fpirit of 
wine, prevents the pump from exhaufting to any confi- 
derable degree. I have made a number of experiments of 
the fame kind as thefe ; but have never been able to ex- 
hauft, under fuch circum fiances, to a greater degree than 
between 50 and 60, when the heat of the room was 
2 about 
