APPENDIX 8 

 KEPORT ON THE ASTROPHYSICAL OBSERVATORY 



SiRr I have the honor to submit the following report on the opera- 

 tions of the Astrophysical Observatory for the fiscal year ended June 

 30, 1950: 



The Astrophysical Obseivatory has continued its two divisions, the 

 Division of Astrophysical Research, devoted to the study of solar 

 radiation, and the Division of Radiation and Organisms, founded in 

 1929 for the study of radiation effects on organisms. 



Beginning September 1, 1948, the Division of Radiation and Organ- 

 isms was entirely reorganized under the new chief of the division. Dr. 

 Robert B. Withrow. During this fiscal year Dr. Withrow's extensive 

 program of remodeling and reconditioning the laboratories was com- 

 pleted and his new research program inaugurated. 



Progress on the new editions of the Smithsonian Meteorological 

 Tables and the Smithsonian Physical Tables can be reported. The 

 sixth edition of the Meteorological Tables was in press at the end of 

 the year, and the manuscript of the ninth edition of the Physical 

 Tables was nearly completed. This new and completely revised 

 edition of the Physical Tables has been compiled under the direction 

 of Dr. WiUiam E. Forsythe. Preparation of this manuscript has 

 proved a colossal task because of the great volume of new material 

 made available since the eighth revision was issued in 1932. 



DIVISION OF ASTROPHYSICAL RESEARCH 



Early in June 1950, the Director left Washington on an inspection 

 trip that included both the Montezuma, Chile, and the Table Moun- 

 tain, Calif., field stations. He spent 16 days in June at the 

 first-named station and 9 days in July at the second. Excellent skies 

 prevailed especially at Montezuma during his stay. Many intercom- 

 parisons of instruments were made, as well as direct comparisons with 

 substandard silver-disk pyrheliometer S. I. No. 5, which he carried 

 with him from Washington. Inventories were made at both stations 

 of all nonexpendable equipment on hand. Various phases of the work 

 were discussed in detail with the personnel of the field stations. 



The Montezuma field station has now been in continuous operation 

 for 30 years. Throughout this period an average of three determina- 

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