572 On the Force of Sicam or Vapour 
in like circumstances; 1000 parts of any elastic 
fluid expands nearly in a uniform manner into 
1370 or 1380 parts by 180° of heat, 
It will be unnecessary to repeat in detail the 
numerous experiments made on the various 
liquids in all temperatures from 32° to 212°; as 
the results of all agree in one general rule or 
principle, which is this: let » represent the space 
occupied by any kind of air of a given temper- 
ature and free from moisture; p= the given 
pressure upon it, in inches of mercury ; ¥ =the 
force of vapour from any liquid in that temper- 
ature, in vacuo; then, the liquid being admitted 
to the air, an expansion ensues, and the space 
occupied by the air becomes immediately, or 
in a short time — 1+ 2 Fi or which is the same 
+5 p 
thing, — pay 
Thus in water for instance : 
Let p = 30 inches, 
ff = 15 inches, to the given temp. 180°, 
Then, os eo Coe The space ; or 
eel aeaane wes Spee : 
the air becomes of twice the bulk, 
-If the temperature be 203°, f = 25, and the 
space becomes 6 times as large as at first. 
If p = 60 inches 
f = go inches to the given temperature 
