Appendix V. 



REPORT OF THE WORK OF THE ASTROPHYSICAL OBSERVATORY FOR 

 THE YEAR ENDING JUNE 30, 1900. 



Sir: The kinds and amounts of the Observatory property are approximately as 

 follows: 



Buildings i»^6, 300. 00 



Apparatus 30,000.00 



Library and records 5, 400. 00 



Total 41, 700. 00 



During the past year the acquisitions of property of the kinds just enumerated 

 have been as follows: 



(a) Aj)paratus. — Astronomical and physical apparatus has been purchased at an 

 expenditure of $2, 100. ' The main separate items are an equatorial mounting for 8-inch 

 telescope, with clock and with coelostat attachment; a 10-inch concave mirror of 75 

 centimeters focus, and a special tremor reducing support and magnetic shielding 

 device designed for use with a new galvanometer of extraordinary sensitiveness. A 

 12-horse power motor with connection to the city electric service, for use in running 

 the cooling plant, has been installed at a cost of |200. 



(b) Library and recorch. — The usual jieriodicals ha\-e been continued, and additional 

 photographic star and moon mai)S have been purchased, the total expenditure for 

 these purposes being |200. 



Total accessions of property, $2,500. 



No alterations of consequence have been made in the Observatory buildings and 

 grounds. The cost of repairs to buildings has aggregated $200. 



Losses of property have been inconsiderable, from a monetary poijit of view, but I 

 regret that a box of holographs containing the originals of some of the illustrations of 

 the forthcoming Volume I of the Annals was injured ])y water during my absence on 

 the eclipse expedition, and the holographs (about 20 in number) were much damaged. 

 It is fortunate, however, that negatives of them are preserved. 



The Work op the Observatory. 



Two objects have principally occupied the Observatory staff during the past year — 

 first, the publication of Annals of the Astrophysical Observatory, Volume I, and, 

 second, the observation of the total solar eclipse of May 28, 1900. Considerable time 

 was, however, devoted to the design and construction of the sensitive galvanometer, 

 with magnetic shielding and steady suj^port above alluded to. 



It will be most convenient to describe the work of the year under three headings, 

 as follows: 



1. Publication. 



2. Progress of the usual work of the Observatory. 



3. Observation of the solar eclipse. 



(1) Publication. — Volume I of Annals of the Astrophysical Observatory, now being 

 issued, containing an account of the research on the infra-red solar spectrum and the 



^I here include only such apparatus as is of permanent value to the Observatory, 

 and not such as served a merely temporary purpose in connection with the recent 

 total solar eclipse. 



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