lb. 
15.2 
10.37 
1.01 
the Source of the Heat excited by Friction . 93 
■, . . , Quantity of ice-cold water which, 
Of the heat excited there appears to with the given quantity of heat, 
might have been heated i8ode- 
have been actually accumulated, or made to boii. 
J In avoirdupois weight. 
In the water contained in the wooden box, 
1 8~lb/avoirdupois, heated 150 degrees, name- 
ly, from6o°to 210° F. 
In 113.131b. of gun-metal, (the hollow cylinder,) 
heated 150 degrees ; and, as the capacity for heat of 
this metal is to that of water as 0.1100 to 1.0000, this 
quantity of heat would have heated 12^ lb. of water 
the same number of degrees - 
In 36.75 cubic inches of iron, (being that part of 
the iron bar to which the borer was fixed which en- 
tered the box,) heated 150 degrees; which may be 
reckoned equal in capacity for heat to 1.21 lb. of water 
N. B. No estimate is here made of the heat accu- 
mulated in the wooden box, nor of that dispersed 
during the experiment. 
Total quantity of ice-cold water which, with the heat 
actually generated by friction, and accumulated in 2 
hours and 30 minutes, might have been heated 180 de- 
grees, or made to boil - 
From the knowledge of the quantity of heat actually pro- 
duced in the foregoing experiment, and of the time in which it 
was generated, we are enabled to ascertain the velocity of its 
production , and to determine how large a fire must have been, 
or how much fuel must have been consumed, in order that, in 
burning equably, it should have produced by combustion the 
same quantity of heat in the same time. 
In one of Dr. Crawford's experiments, (see his Treatise 
on Heat, p. 321,) 371b. 70Z. Troy,= 181920 grains, of water, 
W'" 
0 *. Oz : 
26.58 
5J 
/ 
3 ! ” J 
21 b 4 8 0 * y'Tj 
/ 8 i<) 20 J/ d‘ 
'St 
» 4 /S' 8/ 
Che ,7 3 c. 
Oz 
300 ' 
243 'Z 
7 8/0 'OS 
2 oo ' . 
/Csyz 
' > A 
lx'" 
. . ce^ Si. 
21 "2 crib/ 
'3 
sG Z/0 /L 
=M\ &- 2 g 
//> 
JO 0 z 
, . / 
7 / p sw 
$ 31 - 
