SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 95 



Again, referring to page 252, Annals, volume 5, consider the third 

 line of the first table. The average yearly range from winter to 

 summer of the published mean solar-constant values observed at Mon- 

 tezuma in the period of 10 years from 1921 to 1930 is only from 1.9397 

 calories (the lo-year mean, June to August) to 1.9398 (the lo-year 

 mean, December to February). If the silver-disk pyrheliometer cor- 

 rection factors were omitted, we see from page 69, and from the 



Table i 

 Croup A 



figures just given above, that for the lO-year averages instead of a 

 yearly range of o.oooi calorie (or 5/1000 percent) the solar-con.stant 

 values would have shown an approximate average yearly range from 

 winter to summer of about 0.0180 calorie (or almost an entire 

 1 percent). 



These facts alone show strongly indirect evidence that it is very 

 improbable that the application of the silver-disk correction factors 

 can properly l)e omitted. 



