52 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 



65 



stant temperature gradient " and by Suring's formula for the water- 

 vapor pressure. 



But the purpose of observations of the kind here described is a 

 double one. In the first place, to find the general law for the average 

 conditions, and in the second place to give an idea of the deviations 

 likely to occur from these average conditions. 



Table VIII — India 



Means. 



io.o-ii .0 



10.31 

 10.69 

 10.97 

 10.82 

 10.52 

 10.52 



10.47 

 10.67 

 10.77 

 10.64 



10.64 



0.402 



0.405 

 0.410 

 0.396 

 0.395 

 0.397 

 0.402 



0-435 

 0.440 

 0.436 



0.412 



11. 0-12.0 



H-43 



0.436 

 0.433 

 0.438 

 0.396 

 0.391 

 0.394 

 0.396 



0.412 



D. THE EFFECTIVE RADIATION TO THE SKY AS A FUNCTION OF TIME 



Exner 1 has made a comparison between the radiation values ob- 

 tained at different hours of the night on the top of Sonnblick. He 

 finds that there are indications of a maximum of radiation in the 

 morninsr before sunrise. 



1 Met. Zeitschrift (1903), 9, p. 409. 



