Page:Reflections on the Motive Power of Heat.djvu/111

1 metre of mercury (see Mémoire already cited), taking for the unit the specific heat of the same weight of air under the pressure of 0^m.760.

According to the law that specific heats follow with relation to pressures, it is only necessary to have observed them in two particular cases to deduce them in all possible cases: it is thus that, making use of the experimental result of MM. Delaroche and Bérard which has just been given, we have prepared the following table of the specific heat of air under different pressures:

Specific Heat of Air.

Pressure in Atmospheres.	Specific Heat, that of Air under Atmospheric Pressure being 1.	Pressure in Atmospheres.	Specific Heat, that of Air under Atmospheric Pressure being 1.
${\tfrac {1}{1024}}$	1.840	1	1.000
${\tfrac {1}{512}}$	1.756	2	0.916
${\tfrac {1}{256}}$	1.672	4	0.832
${\tfrac {1}{128}}$	1.588	8	0.748
${\tfrac {1}{64}}$	1.504	16	0.664
${\tfrac {1}{32}}$	1.420	32	0.580
${\tfrac {1}{16}}$	1.336	64	0.496
${\tfrac {1}{8}}$	1.252	128	0.412
${\tfrac {1}{4}}$	1.165	256	0.328
${\tfrac {1}{2}}$	1.084	512	0.244
1	1.000	1024	0.160

The first column is, as we see, a geometrical progression, and the second an arithmetical progression.