34 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



In table I are given : The date, the time of day, the barometric 

 pressure B, the temperature of the air, the humidity (in mm. Hg.) 

 p, and the effective radiation R. The temperature fall between the 

 time of observation in the evening and the time of sunrise is indi- 

 cated by Af. 



Table II 



From figures ia and lb, where the radiation (crosses) and the 

 humidity (circles) are given as functions of time, it is already evi- 



