TABLES 154-155. 



RELATIVE DENSITY OF MOIST AIR FOR DIFFERENT PRESSURES 



AND HUMIDITIES. 



TABLE 154. Values of =^- from h = 1 to h = 9, for the Computation of Different Values of the Ratio 



/OU 



of Actual to Normal Barometric Pressure. 



This gives the density of moist air at pressure h in terms of the density of the same air at normal atmosphere pressure. 

 When air contains moisture, as is usually the case with the atmosphere, we have the following equation for pressure 

 term : h B 0.378*, where e is the vapor pressure, and B the corrected barometric pressure. When the neces- 

 sary psychrometric observations are made the value of e may be taken from Table 150, and then 0.378*? from Table 

 153, or the dew-point may be found and the value of 0.378* taken from Table 153. 



EXAMPLES OF USE OF THE TABLE. 



To find the value of when h 754.3 

 760 



h = 700 gives .92105 



50 ' .065789 



4 .005263 



.3 " .000395 



754-3 



.992497 



To find the value of when h 5.73 

 760 



h =. 5 gives .0065789 

 .7 ' ' .0009210 

 .03 " .0000395 



5-73 



.0075394 



TABLE 155. Values of the logarithms of -g- for values of h between 80 and 340. 



Values from 8 to 80 may be got by subtracting i from the characteristic, and from 0.8 to 8 by subtracting 2 from the 



characteristic, and so on. 



SMITHSONIAN TABLES. 



