108 AXXUAL REPORT SMITHSONIAN INSTITUTION, 1922. 



results. In order to aid these enterprises, the director has designed 

 a full set of solar-constant apparatus, and it is expected that within 

 the next fiscal year two sets will be prepared by contract for the 

 Australian and Argentine stations. 



PERSONNEL. 



Mr. A. F. Moore, field director at Mount Harqua Hala, was added 

 to the staff of the Astrophysical Observatory on July 1, 1921. 



SUMMARY. 



The outstanding event of the fiscal year was the publication in 

 June, 1922, of Volume TV of the Annals of the Astrophysical Observ- 

 ator}'^, covering results from 1912 to 1920. New apparatus and 

 methods are described, a critical survey of the work is given, and 

 long tabular summaries of all solar observations made are included. 

 From these results it is indicated in numerous ways that the sun's 

 output of radiation varies, that the march of its variations depends 

 on the sun's rotation, and that it produces effects of several kinds 

 on terrestrial physics and meteorology. Much progress has been 

 made at the new station on Mount Harqua Hala. Solar-constant 

 observations were made there on over 70 per cent of the days, but 

 are withheld from publication until completely discussed for evi- 

 dences as to systematic errors. Expeditions were made to Chile and 

 to Mount Wilson. 



Eespectfully submitted. 



C. G. Abbot, 



Director. 



Dr. Charles D. Walcott, 



Seo'efary, Smithsonian Institution. 



