APPENDIX 5. 
REPORT ON THE ASTROPHYSICAL OBSERVATORY. 
Sir: I have the honor to present the following report on the opera- 
tions of the Smithsonian Astrophysical Observatory for the year 
ending June 30, 1914: 
EQUIPMENT. 
The equipment of the Observatory is as follows: 
(a) At Washington there is an inclosure of about 16,000 square 
feet, containing five small frame buildings used for observing and 
computing purposes, three movable frame shelters covering several 
out-of-door pieces of apparatus, and also one small brick building 
containing a storage battery and electrical distribution apparatus. 
(6) At Mount Wilson, Cal., upon a leased plot of ground 100 
feet square, in horizontal projection, are located a one-story cement 
observing structure, designed especially for solar-constant measure- 
ments, and also a little frame cottage, 21 feet by 25 feet, for observer’s 
quarters. 
Upon the observing shelter at Mount Wilson there is a tower 40 
feet high above the 12-foot piers which had been prepared in the 
original construction of the building. This tower has been equipped 
with an improvised tower telescope for use when observing (with 
the spectrobolometer) the distribution of radiation over the sun’s 
disk. 
During the year apparatus for research has been purchased or 
constructed at the Observatory shop. The value of these additions 
to the instrumental equipment, not counting the tower above men- 
tioned and its equipment, is estimated at $1,500. 
WORK OF THE OBSERVATORY. 
AT WASHINGTON. 
Observations.—Mr. Fowle has continued the difficult research on 
the transmission through moist air of radiations of great wave 
length, such, for instance, as those which bodies at the temperature 
of the earth emit most freely. He uses a very powerful lamp made 
up of a large number of Nernst electric glowers, and examines by 
the aid of the spectrobolometer the energy spectrum of the rays 
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