SECT. II.] 
PROPERTIES OF STEAM. 
53 
State of the calorimeter, equal in specific heat to 
42909 grains of water. 
Temperature of 
the room. 
Temperature at 
the beginning. 
Temperature at 
the end. 
Elevation of its 
temperature. 
Quantity of va 
pour condensed 
into water. 
Heat of conver 
sion of the water 
into vapour 
in degrees. 
61° 
55i° 
674° 
12i° 
Grains. 
457 
1029°*3 
62i 
57 
67i 
10i 
377 
1052-3 
Mean 
- 1040-81 
The result of the second experiment being compared by our formula, (note to 
art. 75,) we have 
42909 x 10i 
377 
+ 67i = 1262°-5, 
from whence, deducting 212° on the supposition that the specific heat of steam is 
equal to that of water, we have 1050 o, 5 for the constant quantity of heat for con 
version into steam. The very small difference between this and Count Rumford’s 
result, arises from the fractions neglected in reducing the French to English weights. 
80. Count Rumford also made experiments on the quantity of heat developed 
in the condensation of the vapour of alcohol: the results of these experiments were 
less regular than those of the experiments made with water, as might have been 
expected, but they were nevertheless sufficiently uniform to give the quantity of 
heat with considerable certainty. 
The vapour which is extricated from spirit of wine, when boiled, varies a little 
with the intensity of the fire used in boiling it; he took care therefore to note the 
time which was taken in every experiment, in order to be able to judge, by com 
paring the quantity of vapour condensed with the time employed to form it, of 
the intensity of the heat employed to boil the liquid. In the following table will 
be found the details and results of five experiments made on the same day, 
(January 21, 1812,) with alcohol of different degrees of strength. The specific heat 
of the calorimeter and the water it contained, was always equal to that of 42909 
grains of water; and the thermometer employed was that of Fahrenheit. 
Specific gra 
vity of the 
alcohol em 
ployed. 
Time em 
ployed in the 
experiment. 
Temperature 
of the apart 
ment. 
State of the calorimeter. 
Quantity of 
alcohol con 
densed in the 
calorimeter. 
Heat of con 
version of the 
liquid into 
vapour. 
Temperature 
at the begin 
ning. 
Temperature 
at the end. 
Elevation of 
its tempera 
ture. 
81763 
84714 
85342 
85342 
85342 
4i min. 
8 — 
7 — 
5 — 
61° 
601 
61 
61 
64 
56° 
55i 
54i 
56 
57 
661° 
65| 
68i 
66i 
71i 
101° 
10 
141 
10i 
14i 
Grains 
875 
755 
1079 
805 
1102 
479°-92 
500-03 
499-54 
476 83 
499-65 
Mean - 49113 
i Philosophical Mag. voi. xliii. p. 65.