KODUCT1 



C. For steam from 100 to aao C, 

 log p - a - ba* + r0". 



log 6 - o .4121470. 

 log c - 7.7448001 - 10. 

 log - 9.997412127 - ia 

 log 0-0.007 590697- 



-* / - 100. 



D. For steam from - 20 to 220 C, 

 log^ - a - ba* - . 



a - 6.2640348. 

 log 6 - o. 1397743- 

 log c - 0.6924; 

 log a -9.994049292 - 10. 

 log - 9.998343862 - 10. 



II - / + 20. 



aid of the formula! A and B, Regnault calculated and recorded 



of th'- pressures of saturated steam for temperatures from - 32 



to 100 C. The formula D was calculated from the data given above 



for tin- umjwratures - 20, + 40, 100, 160, and 220 C., and was 



:!u- whole range of experiments. By this formula, 



instead of formula C, he calculated the pressures set down in his tables 



.res from 100 C. to 220 C. In the calculations of the 



TIN and in their application to computations of pressures at given 



temperatures, there is an inevitable loss of accuracy 90 that the result* do 



not agree satisfactorily with the original data. 



Equations for the Pressure of Steam at Paris. In view of the preceding 



appeared desirable to re-calculate the constants for Equa- 



B and C, with a degree of accuracy that should exclude any doubt 



as to the reliability of the refills. Accordingly, the logarithms required 



taken from Vega's ten-place table, and then the remainder of the 



calculations were carried on with natural numbers, checking by inde- 



pendent methods, with the following results: 



B. For steam from o to 100 C, 

 log p - a - &a" + , 



- 4-7393622142. 

 log b -0.6117400100, 

 log.c - 8. 1320378383 - 10. 

 log a - 9.996725532820 - ia 

 log ft - 0.006864675924. 

 M - /. 



