HYGROMETRICAI, TABL,ES. XXXV 



TABLES 33, 34. 



Barometric pressures corresponding to the temperature of boiling water. 



Table 33. English Measures. 



Table 34-. Metric Measures. 



Table 33 is a conversion into English measures of Table 34. The 

 argument is the temperature of boiling water for every tenth of a degree 

 from 185^0 to 2i2r9 Fahrenheit. The tabular values are given to the 

 nearest 0.0 1 inch. 



Table 34 is Regnault's table of barometric pressures corresponding to 

 temperatures of boiling water, revised by A. Moritz {Acad. Sci. Bull., St. 

 Petersburg, xiii., 1855, col. 41-44). To the degree of precision here desired, 

 these values do not differ from the more recent reduction by Broch. The 

 argument is given for every tenth of a degree from 8o°o to loofQ C. The 

 tabular values are given to the nearest o. i mm. 



HYGROMETRICAIv TABI.ES. 



PRESSURE OF AQUEOUS VAPOR IN SATURATED AIR. 



Tables 35, 36, and 43, giving the pressure of aqueous vapor in saturated 

 air, are based upon Dr. Broch' s reduction of the observations of Regnault 

 {Travaux et Mimoires du Biireau international des Folds et Mesures, t. I, 

 p. A 19-39). This reduction assumes that the observations may be repre- 

 sented by the empirical formula 



bt + ct^ + dV^ + et^ +//5 

 F^A X 10 ■ — 



1 -{- at 



in which F is the pressure of aqueous vapor expressed in millimetres of 

 standard mercury, that is at 0° C. and at latitude 45° and sea 

 level, its density being 1 5- 59593- 

 /, the temperature expressed in normal Centigrade degrees. 

 a = 0.003667458 



By using the simultaneous values of F and / given by Regnault's 

 observations, Dr. Broch obtained a series of observation equations whose 

 solution by the method of least squares gave the following values for the 



coefficients : 



A= 4.5686859 



b= 10-2 X 3. 134 366 174 



^ = — IO"5 XI.416112423 



d= 10-7 X 1.935338308 

 <? = — 10-9 X 2.646 535 103 

 /= IO-" X 1.139377 15S 



From this formula Broch' s tables of vapor pressure were computed. 



