G(jO reports of astronomical observatories. 



Its'STRUMENTS: 



(c) Equatorial instrument : maker, John Byrne, of New York ; ap- 

 erture of objective, 4r-^ iuclies; focal distance, 65 inclies; magnifying 

 powers of eye-pieces, 20, 30, 45, GO, 80, 150, 250, 300, 350, and 450; also 

 an amj)lifier, which doubles each of these powers when used. Attached 

 to the telescope is a finder of 1^ inches aperture, magnifying 20 diame- 

 ters. Eight ascension circle divided to read to 4 seconds of time; dec- 

 lination circle divided to read to V of arc. Both circles divided on 

 silver and read by microscopes attached thereto. Driving-clock. 



(d) Spectroscope: one. 



(r/) ClocTi: mean time; maker, Seth Thomas, Sons & Co. 



(i) Miscellaneous: Filar micrometer; divided on silver to measure 0".3 

 of arc in distance and 6' in position, with suitable eye-pieces and illu- 

 minating apparatus. 



Observations during the past year: 



No observations have been systematically made during the year ending 

 January 1, 1881, owing to the removal of the observatory and the con- 

 sequent confusion arising therefrom. 



Eochester, Monroe County, New YorTc. 

 Warner Observatory. 



Longitude from Washington, 3™ 8^ W. 



Latitude, 43° 8' 11" K 



Authority, for latitude and longitude : Signal Service officer. 



Director: Lewis Swift. 

 Instruments : 



(c) Equatorial instrument : makers, Alvan Clark & Sons (con- 

 structing); aperture of objective, 16 inches; magnifying powers of eye- 

 pieces, from 45 to 2000. (c') Altitude-azimuth, 4J inches, by Fitz; 

 powers from 25 to 432. Telescope 4^-inch refractor, originally by Fitz, 

 but since last report the flint lens of the objective was unfortunately 

 broken; it has been replaced by Alvan Clark & Sons. lis perform- 

 ance, which was always good, appears to be rather better than before 

 the accident. 



Observations during the past year: 

 The work done during the past year has been a repetition of that for 

 several years past, viz, comet seeking and observing those discovered 

 by others. The nebulae observed and heretofore overlooked, which, 

 however, are very few in number, have been also carefully recorded on 

 star charts. This facilitates the prompt detection of a comet. Much 

 caution, however, is necessary not to announce and especially not to 

 cable the discovery of a comet where no motion has been detected. 



