APPENDIX 5. 



REPORT ON THE ASTROPHYSICAL OBSERVATORY. 



Sir : The Astrophysical Observatory was conducted under the fol- 

 lowing passage of the sundr}^ civil act approved June 12, 1917: 



Astrophysical Observatory: For maintenance of Astrophysical Observatory, 

 under the direction of the Smithsonian Institution, including assistants, pur- 

 chase of necessary books and periodicals, apparatus, making necessary observa- 

 tions in high altitudes, repairs and alterations of buildings, and miscellaneous 

 expenses, $13,000. 



For observation of the total eclipse of the sun of June eighth, nineteen hun- 

 dred and eighteen, including purchase of necessary apparatus and supplies, 

 transportation of equipment to and from observing station, hire of temporary 

 assistance, transportation and subsistence of observers, and miscellaneous 

 expenses, $2,000. 



The observatory occupies a number of frame structures within an 

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

 ministration Building at Washington, and also a cement observing 

 station and frame cottage for observers on a plot of 10,000 square 

 feet, leased from the Carnegie Solar Observatory on Mount Wilson, 

 Cal. 



Its equipment comprises special optical, electrical, and other appa- 

 ratus adapted to measure radiation of the sun, the sky, and terrestrial 

 sources. Much of the apparatus has been built at the observatory 

 instrument shop on the Smithsonian grounds in Washington ac- 

 cording to designs of the director. The instrument maker, Mr. A. 

 Kramer, has been employed by the observatory nearly 30 years 

 in this experimental construction work, and his experience and 

 skill, added to his natural ability, render him invaluable. New 

 designs are continually being worked out as new experiments are 

 being made. 



The present value of the buildings and equipment is estimated at 

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

 the outfit for the purposes of the investigations. Owing to the 

 highly specialized character of the apparatus no such value could be 

 obtained at public sale. 



WORK OF THE YEAR. 



At Washington. — As heretofore the work of measuring and com- 

 puting from the records obtained in the field on Mount Wilson has 



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