APPENDIX 7 

 REPORT ON THE ASTROPHYSICAL OBSERVATORY 



Sir : I have the honor to submit the following report on the activi- 

 ties of the Astrophysical Observatory for the fiscal year ended June 

 30, 1935 : 



This observatory comprises : (a) The central station at Washington 

 where apparatus is made and standardized; where reports are com- 

 puted, written, and published; where preparations for expeditions 

 are made; and where a general oversight is maintained of the field 

 stations, (h) A station on Mount Wilson, near Pasadena, Calif., 

 where brief expeditions for special researches go from time to time. 

 (c) A station on Table Mountain near Swartout, Calif., where daily 

 observations of the solar constant of radiation are carried on. (d) 

 A similar solar-constant station on Mount Montezuma, near Calama, 

 Chile, (e) A similar station on Mount St. Katherine near Mount 

 Sinai, Egypt. These stations are supported principally by annual 

 Government appropriations, but in a considerable part by private 

 funds. 



REVISION OF SOLAR-CONSTANT METHODS 



Records of daily observations at Mount St. Katherine since Decem- 

 ber 1933 being available, a complete reduction of them was under- 

 taken by the assistant director, L. B. Aldrich. Additional assistance 

 was generously made available under a grant from John A. Roebling, 

 so that at times as many as six computers assisted Mr. Aldrich in 

 this work. By these means he was able to compute numerous " long 

 method " values of the solar constant of radiation, base thereon a 

 suitable " short method " of reduction, and compute so many values 

 by the short method as to show that the Egyptian station bids fair 

 to prove of high excellence. Although the complete computation of 

 all available days would not be finished before August 1935, Mr. 

 Roebling was so far pleased and satisfied with the results from Mount 

 St. Katherine, and so impressed with the need of this cooperating 

 station, that in June 1935 he made a further grant to finance its 

 occupation as a solar radiation station until 1938. At the same time 

 he provided for a revision and extension of " short method " tables 

 for the stations at Montezuma, Chile, and Table Mountain, Calif., 

 which will be undertaken as soon as the work of reduction for Mount 

 St. Katherine is completed. It is pleasant to recall that the project 



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