Tables 113-114, 



^33 



RELATIVE DENSITY OF MOIST AIR FOR DIFFERENT PRESSURES 



AND HUMIDITIES. 



TABLE 113.— Values of 



760' 



from h = l to ft = 9, for the Computation of Diflferent Values 



of the Ratio of Actual to Normal Barometric Pressure. 



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

 sure. When air contains moisture, as is usually the case with the atmosphere, we have the 

 following equation for pressure term: /i = B — 0.378^, where e is the vapor pressure, and B the 

 corrected barometric pressure. When the necessary psychrometric observations are made the value 

 of e may be taken from Tabl? 189 and then 0.378? from Table 115, or the dew-point may be found 

 and the value of 0.378^ taken from Table 115. 



Examples of Use of the Tablb, 



To find the value of — when /i r= 754.3 

 760 



A = 700 gives .92105 



^ 



754-3 



065789 

 005263 

 000395 



To find the value of — when /i = 5.73 

 760 



/« = 5 gives .0065789 

 ,7 " .0009210 

 .03 " .0000395 



5-73 



.OC7^:?04 



TABLE 114, —Values of the logarithms ot ~ for values of 7i between 80 and 340. 



Smithsonian Tables. 



