80 ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 3 6 



PERSONNEL 



No changes of personnel have occurred other than the shiftmg of 

 observers from one field station to another, except that on April 16, 

 1936, Alfred G. Froiland reported as bolometric assistant to take 

 station at Mount St. Katherine. 



SUMMARY 



The year has been distinguished for the introduction of a new 

 criterion for distinguishing unsatisfactory sky conditions at the 

 solar-constant stations. This will add decidedly to the accuracy and 

 harmony of the results. Studies of the variability of the sun over an 

 interval of 15 years have disclosed many periodicities, all aliquot 

 parts of 23 years, which altogether make up the apparently irregular 

 solar variation of long term. The cycle of 23 years is abundantly 

 evidenced in weather and things dependent thereon. Besides this it 

 is shown that the weather is to a great extent governed for at least 

 2 weeks afterward by the initiation of incidental rising or falling 

 solar radiation, usually of only a few days' duration. Expert opinion 

 concurs that this affords a promising method of forecasting certain 

 weather features for at least 2 weeks in advance. Unfortunately, it 

 requires expansions of our solar-observation program, which thus 

 far there are no funds to finance. Papers detailing these investi- 

 gations w^ere published by the Director in the Smithsonian Miscel- 

 laneous Collections under the following titles: "The Dependence of 

 Terrestrial Temperatures on the Variations of the Sun's Radiation", 

 "Further Evidence on the Dependence of Terrestrial Temperatures 

 on the Variations of Solar Radiation", and "Solar Radiation and 

 Weather Studies." 



Respectfully submitted. 



C. G. Abbot, Director, 



The Secretary, 



Smithsonian Institution. 



