SECRETARY'S REPORT 



131 



The ninth revised edition of the Smithsonian Physical Tables is in 

 press. At the end of the fiscal year, Dr. Forsythe, who prepared the 

 manuscript, had corrected approximately one-third of the galley 

 proof. 



Work in Washington. — The checking and appraisal of observations 

 of sun and sky radiation made at two high-altitude field stations, 

 Montezuma (Chile) and Table Mountain (Calif.), have continued 

 under the direction of Mr. Hoover. Some progress has been made in 

 the preparation of material for a new volume of the Annals of the 

 Astrophysical Observatory. 



Incident to the review of results during the past decade, an exam- 

 ination was made to determine what, if any, relationship is apparent 

 between the solar-constant record and the number of sunspots. During 

 the last maximum of sunspots in 1947, the total number of spots was 

 greater than during any maximum since 1778. In 1947 the number 

 averaged 151.6. In 1778 it was 154.4. The next greatest maximum, 

 139.1, occurred in 1870. A curve is here presented showing monthly 

 mean values of the solar-constant compared with monthly means of 

 sunspot numbers for the same days. It includes all solar constants 

 graded fair or better during the 11-year period 1940 to 1951. A fairly 

 regular increase in solar constants is apparent with increasing sunspot 

 numbers. 



1.950 



\fi 



b8 



11/ 



10 



1.6 



T 



(The number near each point 

 indicates the number of monthly 

 means included in each group.) 



\ . --13 



\i 6 _. Jio 



•^7J 



'W 



-® 7? 



Sunspot numbers 



12T 



i?o 



175 



Figure 1. — Monthly mean values of the solar constant compared with monthly 

 means of sunspot numbers for the same days. 



