REPORTS OF AsriJONOMK'Ar. OBSERVATORIES. ()85 



Dublin, Ireland. 

 7>ini.siiik Oh.scrratory. 



Longitude from (h-ecnwicli, 25'" 21'' W. 



Latitude, 53° 23' V.V N. 



Authority for latitude aud longitude: J)r. liuuNXOW. 



I)i}-€cfor,s: II. Usshek, 1774; 



J. Brinkley, 1792; 



W. K. Hamilton, 1827; 



F, Brunnow, 1805 ; 



Prof. Robert S. Ball, LL.I)., F. K. S., Astronomer Royal 

 of Ireland^ 1875. 

 Assistant: J. L. E. Dkeyer. 



Observatory of Trinity College. 



Founded in 1771, by means of the legacy left for the i)urpose by F. 

 Andeews; built in the midst of a vast park at Dunsink, IV} miles (6 

 kilometers) northwest of Dublin. It was not finished until 1792. A 

 structure of three stories, surmounted by a revolving dome. 

 Instruments : 



(«) Meridian circle: makers, PiSTOR & Martins; diameter of circles, 

 36 inches; divided to 2'; read by 8 microscopes to 1"; aperture of ob- 

 iective, G.4 inches ; magnifying power ordinarily employed, 180 diam- 

 eters. 



(h) Meridian transit instruments : one, made by Kamsden; aperture, 

 4 inches: not in use. {h') One with reversible circle by Ramsdbn & 

 BerCtE ; object-glass, 3 inches ; diameter of circle, 8 feet ; 3 micrometers: 

 not iu use. 



(c) Uquatorial instruments: one; makers, Cauchoix object-glass, 

 Grubb mounting; aperture of objective, llj inches; magnifying powers 

 of eye-pieces, 300: is generally used. {&) One of four inches aperture ; 

 English equatorial by Tulley. (?) Hardly ever used. 



(d) Spectroscopes : one of Browning's two-prism spectroscopes ; and 

 one of Vogel's small-star spectroscopes. 



(/) Chronograph: maker, Grubb; two barrels and controlled clock. 



{g) Clocks: one mean time; maker, Booth of DubUn : one sidereal; 

 maker, Dent, London. 



(//) Chronometer : sidereal ; maker, M'Master. 



(/) Miscellaneous: The mean-time clock controls by electricity the 

 clocks in the port and docks board and Trinity College, the distance 

 being about five miles from Dunsink. 



Dunsink Observatory belongs to Trinity College, Dublin. An annual 

 visitation of the Observatory is held every summer by the board of 

 Trinity College. 



Observations during the past year (1880) : 



The meridian observations of red stars (commenced by Dr. Cope- 



