AP P E N D 1 X. 329 
plrations of an Houri and in twenty foui: 
Homs 9791 Grains, or i. 39-Poiind; which 
fuppofing the Surface of the Lungs to be as 
found in Vol. I. p. 242. 4i6'3y fquare Inches, 
then the Qiiantity evaporated from that in- 
ward Surface will be part of an Inch 
depth. 
Experiment VII. 
I. ^ I ^HE Confideration of the continued 
jL Succeflion of frefli Air, which is 
found neceffary to keep a Fire burning ; alfo 
of the intenfe Degree of Heat which a Fire 
foon acquires by' being vigoroufly blown on 
by Bellows ; thefe Confiderations put me 
upon trying by Experiment what the Velo- 
city and Force of that Air might be 5 which 
I found by applying a proper mercurial Gage 
to the Nofe of a Pair of Smith’s Bellows ; 
whereby I found the Force of the compreffed 
Wind in the Bellows, was fufficient to raife 
the Mercury in the Gage about an Inch high, 
fometimes a little more and fometimes a little 
lefs. Whence the Force with which the Bel- 
lows impel Air into the Fire, is nearly equal 
to ^th Part of the Weight of the Atmo- 
fpherCa 
