220 Love and Smeal: Pyschrometric Formula 



less humidity may be expected, and it is possible that the value 

 of A will then be found to be somewhat lessened. The results 

 so far have shown no systematic dependence of A on wind- 

 velocity or direction, though there appears to be a tendency 

 for it to decrease as the velocity rises and as the wind changes 

 from north to south. In calm air the - values are certainly 

 larger than when the air is moving. This is in accordance with 

 the results of other observers and with the Stefan-Maxwell 

 theory. The mean value of A for calm air is 0.0008370, for 

 moving air 0.0006806 ; the latter number agrees nearly with 

 those obtained by others using artificial ventilation. 



In conclusion we desire to record our thanks to Professor 

 Lyle for the kindly interest which he has shown, and for the 

 loan of the thermometers, which has enabled the work to be 

 done in a satisfactorv manner. 



