136 
de. joule on the theej^ial eeeects oe co:mpeessin& fluids. 
Tempera- 
ture ill 
degree 
Centigrade. 
t. 
Expansibility by 
heat per degree 
Centigi’ade. 
e. 
Pressure 
in pounds 
on the 
square foot. 
P- 
Capacity 
for heat of 
a cubic foot 
of the oil, 
in pounds 
of water. 
K. 
Deflections of fhe needle, 
each the mean of ten 
observations. 
Value of the 
deflections. 
16 
•0007582 
16777 
29-83 1 
32-31 
32-5 
Mean 32*4 
95o' = 2-11 
17-29 
•0007582 
33117 
29-83 1 
64-31 
66*0 
. Mean 65-15 
867 = 2-04 
16-27 
•0007582 
53634 
29-83 1 
108-7' 
109*3. 
?■ Mean 109 
950 = 2-11 
Experimental Theoretical 
, thermal effect 
increased 
bv one-tenth. 
effect, or 
373- ftp 
JK 
0-0792 0-0886 
0-1686 0-1758 
0-2663 0-2837 
The specific heat of the oil was found by the method of mixtures to be 0 o o a 
16--5, Its expansion, determined by the weight of a volumenometer RUed with it at 
various temperatures, proved to be -0007582 at 2r-3. Its specific graw^' at 0 
0-915. It was important to ascertain its specific heat and expansion at a tempe 
near that which it had in the experiments, because, though quite transparent, it ecame 
considerably more fluid when the temperature was much raised Such a ^adnal c ange 
of state in any viscous substance is accompanied by the absorption of latent heat and 
an increase in the rate of expansion, which are greatest at the temperatiu-e at which the 
change of state is most rapid. 
