APPENDIX 7 

 REPORT ON THE ASTROPHYSICAL OBSERVATORY 



Sir : The Astrophysical Observatory was conducted under the fol- 

 lowing passage of the independent offices appropriation act approved 

 February 11, 1927 : 



Astxophysical Observatory : For maintenance of the Astrophysical Obsei'va- 

 tory, under the direction of the Smithsonian Institution, including assistants, 

 purchase of books, periodicals, and apparatus, making necessary observations 

 in high altitudes, repairs and alterations of buildings, preparation of manu- 

 scripts, drawings, and illustrations, traveling expenses, and miscellaneous 

 expenses, $32,060, of which amount not to exceed $29,000 may be expended for 

 personal services in the District of Columbia. 



The observatory occupies a number of frame structures within an 

 inclosure of about 16,000 square feet south of the Smithsonian Admin- 

 istration Building at Washington, a cement observing station and 

 frame structure for observers on a plot of 10,000 square feet leased 

 from the Mount Wilson Observatory, and an observing station on 

 Table Mountain, Calif. This last station, provided by Mr. John A. 

 Roebling, includes a tunnel for instruments, small structures for the 

 field director and for the assistant, a shop, and a garage. 



The Astrophysical Observatory also defrays a part of the cost of 

 the maintenance of the observing station at Montezuma, Chile, which 

 was erected in 1920 with means furnished by Mr. Roebling. The 

 constructions there comprise a tunnel for instruments, a small struc- 

 ture for observers, shop, garage, and a telephone line 12 miles to 

 Calama. 



The present value of the buildings and equipment for the Astro- 

 physical Observatory owned by the Government is estimated at 

 $50,000. This estimate contemplates the cost required to replace the 

 outfit for the purposes of the investigations. 



WORK AT WASHINGTON 



{a) Reduction of observations. — Three field stations — Table INIoun- 

 tain, Calif., Montezuma, Chile, and Brukkaros, South West Africa — 

 are now steadily sending results of daily observations of the intensity 

 of solar radiation to the Smithsonian Institution. The work of com- 

 paring these observations, of detecting and determining sources of 

 error, and correcting therefor, and the care of keeping the three 

 stations, thousands of miles away in the wilderness, supplied with 



ill 



