2 6 PROPERTIES OF STEAM AND OTHER VAPORS. 



use some such approximate method, and it does not appear profitable to 

 recompute tables at thi> time. 



Fortunately Regnault determined the relation of temperature and 

 pressure, and gave the following equations for pressure in millimetres of 

 mercury, the temperature being on the Centigrade thermometer. 



SULPHUR DIOXIDE. AMMONIA. 



log p - a - ba - eft* log p - a - ba n - eft* 



a - 5.6663790 a - 11.5043330 



b - 3.0146890 b - 7.4503520 



c = 0.1465400 c -= 0.9499674 



log a - 9.9972989 - 10 log a = 9.9096014 10 



log ft - 9.9872000 10 log ft = 9.0939729 - 10 



n - / + 28 n = / + 22 



Limits, - 28, + 62. Limits, - 22, + 82. 



The corresponding equations for pressures in pounds per square inch 

 for temperatures Fahrenheit are: 



SULPHUR DIOXIDE. AMMONIA. 



log p = a ba n eft" log p = a - ba n - cft n 



a = 3.9527847 a = 9.7907380 



log b 0.4792425 log b = 0.8721769 10 



log c = 9.1659562 10 log c = 9.9777087 10 



log a = 9.9984994 - 10 log a = 9.9997786 10 



log ft = 9.99293890 - 10 log ft = 9.9966516 10 

 n = / -I- i8.4F. n = t + 7.6 F. 



In the Thermodynamics of the Steam-engine by the author, pages 1 1 7 

 to 126, this calculation has been carried out with the best ascertained 

 properties of the superheated vapors of sulphur dioxide and ammonia 

 with the following results: 



SULPHUR DIOXIDE. AMMONIA. 



French units, pv = 14.5 T - 48 p* M frv = 54.3 T - 

 English units, pv = 26.4 T - 184 p' M pv = 99 T - 



The application of these equations to the vapors when saturated gives 

 the following results: 



