Mechanical Theory of Heat to the Steam Engine. 31 
For this purpose I have used above 100° the numbers cited by 
Regnault* himself. Moritz} has recently directed attention to the 
fact, with reference to the values under 100°, that the formula 
which Regnault has applied between 0° and 100° is somewhat 
inaccurate, particularly m the neighborhood of 100°, in conse- 
quence of the use of seven-figure logarithms in calculating the 
constants. Moritz has therefore calculated these constants with 
ten-figure logarithms, assuming the same values from observ- 
ation, and has communicated the values of p deduced from 
a 
I have collected the values of g and 7’ g, thus found in a ta- 
ble communicated at the end of this memoir. For the sake of 
completeness I have added the values of p belonging to, them, 
those of Regnault above 100°, those calculated by Moritz below 
100°. In each of these three series of numbers, the differences 
of every two successive numbers are given, so that we may fin 
from this table, for every given temperature, the values of those 
three quantities, and conversely, for every given value of one of 
those three quantities, the corresponding temperature. 
After what has already been said as to the calculation of g, I 
scarcely need to add that I do not consider the numbers of this 
e 
always rest upon rather uncertain data, we may apply for this 
Purpose these numbers without hesitation, without phen 9 
fear that the uncertainty of the result will be thereby sensibly 
increased, ; 
g are expressed in kilograms upon a square meter; in the tu- 
bles, on the contrary, the same unit of pressure is retained to 
which contain neither p norg as a factor by the number 13°596. 
I will, for the sake of brevity, denote this number, which is 
at of water at its maximum density, by &. ; 
This modi fication of the formulas produces almost no increase 
of calculation, inasmuch as it consists in substituting in every 
* Mém. de l’Acad. des Sciences, T. xxi, p. 625. = 
+ Bulleti ico-mathematique de l’Acad. de St. Petersburg, T. xii, 
ms tin de la Classe physico-ma\ tique | 
