APPENDIX 8 
REPORT ON THE ASTROPHYSICAL OBSERVATORY 
Sir: I have the honor to submit the following report on the opera- 
tions of the Astrophysical Observatory for the fiscal year ended June 
30, 1946: 
The Astrophysical Observatory comprises two divisions: (1) The 
Division of Astrophysical Research which is devoted to a study of 
solar radiation, and (2) the Division of Radiation and Organisms 
which investigates the effects of radiation upon organisms. ‘The Ob- 
servatory is supported largely by Congressional appropriation, 
amounting in this fiscal year to $51,039, and in part by private funds, 
The equipment and housing of both divisions have remained nearly 
unchanged during the year. 
(1) DIVISION OF ASTROPHYSICAL RESEARCH 
Work at Washington.—In addition to the usual routine of correct- 
ing, recomputing, and verifying the solar observations as received 
from the three field stations (Montezuma, Chile; Table Mountain, 
Calif.; and Tyrone, N. Mex.), a tabulation was made, after critical 
study, summarizing the solar record for the calendar year 1945. These 
values add another year to the great table of volume 6 of the Annals 
referred to in last year’s report. Progress has also been made in the 
continued search for possible improvements in solar-constant instru- 
mentation and methods. A new vacuum bolometer, designed by L. 
B. Clark, technologist of the Observatory, is in preparation. This 
new design will eliminate the gradual loss of sensitivity which we have 
noted in the past arising from certain impurities in the vacuum 
chamber. 
Reference was made in last year’s report to a contract, signed in 
June 1945, with the Office of the Quartermaster General, Army Service 
Forces, under the terms of which the Observatory is to make a detailed 
study of sun and sky radiation at Camp Lee, Va., as part of extensive 
tests in progress there to determine the causes for the deterioration of 
tents and tent fabrics. It is known that radiation from the sun and 
sky falling upon exposed fabrics over extended periods is a factor 
which hastens deterioration in the fabrics. Practically nothing is 
known, however, of the amount of radiation required, nor of the part 
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