ASTRONOMICAL OBSERVATORIES. 421 



Directors : U. UssnER, 1774. 

 J. Brinkley, 1792. 

 W. E. Hamilton, 1827. 

 F. Beunnow, 18G5. 

 Egbert S. Ball, Astronomer Eoyal of Ireland, 1875. 



J3unsiuk Observatory belongs to Trinity College, Dublin. It was 

 founded in 1774, by means of a legacy left for tbc purpose by F. An- 

 drews. It is built in the midst of a vast park at Dunsink, 3f miles (6 

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

 is a structure of three stories, surmounted by a revolving dome. An 

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

 of Trinity College. 



Instruments : 



(«) Meridian circle : IMakers, PiSTOR & Martins j diameter of circles, 

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

 jective, 6.4 inches; magnifying power ordinarily employed, 180 diam- 

 eters. 



{b) Meridian transit instruments : One, made by Eamsden; aperture, 

 4 inches; not in use. {!/) One with reversible circle by Eamsden & 

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

 not in use. 



(c) Equatorial instruments : One; makers, Cauchoix object-glass, 

 Grubb mounting; aperture of objective, 11:] inches; magnifying powers 

 of eye-pieces, 300; is generally used, (c') One of 4 inches aperture; 

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



{d) Spcctroscojoes : One of Browning's 2-prism spectroscopes; and 

 one of Vogel's small-star spectroscopes. 



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



{(j) Clocks: One mean time; maker, BooTii, of Dublin ; one sidereal; 

 maker. Dent, Loudon. 



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



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

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

 being about 5 miles from Dunsink. 



Dun Echt (Aberdeen), Scotland. 



Longitude from Greenwich, 9™ 40« W. 



Latitude, 57^ 9' 30" N. 



Authority' for longitude: Ordnance Survey; for latitude, observations 

 with a SiMMs's alt azimuth. The transit circle confirms the re- 

 sult within a fraction of a second. 



Astronomer : Ealph Copeland. 

 Dun Echt Observatory, the property of the Earl of Crawford 



AND Balcarres (late Lord Lindsay), is on the estate of Dnn Echt, 



about 13 miles west of Aberdeen. 



