370 astronomical observatories. 



Ann Arbor, Michigan. 



Detroit Observatory. 



Longitufle from Washington, 2G"' 43.1* W. 

 Latitiule, 42o IG' 48" N. 

 Directors : F. Brunnow, 1854. 



J. C. Watson, LS58. 



M. W. Harrington, 1879. 

 Annex of the University of Michigan. Projected in 1852, commenced 

 in 1853, completed in 1854. The principal structure is surmounted by a 

 dome and has two wings. About thirty planetoids have been discov- 

 ered here. 



Annapolis. Maryland. 



U. S. Naval Academy Observatory. 



Longitude from Washington, 2'" 15.G1» E. 

 Latitude, 38° 58' 53.48" X. 



Authority for longitude, U. S. Coast Survey; for latitude, Professor 

 Chauvenet. 



Director: Lieut. Commander P. F. Harrington, head of department 

 of astronomj', navigation, and surveying. 



The officers attached to tbe observatory are occupied in duties of in- 

 struction in the department of astronomy, navigation, and surveying. 

 The instruments are used in the course of instruction, but regular ob 

 servatious are not made for purposes of astronomical investigation. 

 Instruments : 



{a) Meridian circle: One; maker, Eepsold, Germany; diameter of 

 circles, 30 inches; divided to 2'; read by 4 microscopes to 2". Aperture 

 of objective, 4 inches; for observations of the sun, aperture employed, 

 — inches; magnifying power ordinarily employed, 80 diameters. 



(b) Meridian transit instrument: Maker, Wurdemann; aperture, 2 

 inches ; magnifying power, 40 diameters. 



(c) Equatorial instrument: Makers, Alt AN Clark & Sons; aperture 

 of objective, 7^ inches; magnifying power of eye-pieces, 40, 106,553, 

 and 9GG; micrometer eye-pieces, 89, 226, 673. 



(/) Chronograplis : One Morse fillet; one Transit of Venus Commis- 

 sion. 



(<7) Clod:: One sidereal; makers, Arnold, Chas. Frodsham, London. 



(Ii) Chronometers : Five mean time; makers, Negus, IS'os. 1030, 1088, 

 1260; Dent, 2,099; Hatton, 2G2: two sidereal; maker, Negus, Nos. 

 1520, 1527. 



(«■) Miscellaneous: One Talcott's zenith telescope (Wurdemann); one 

 Transit of Venus telescope (Stackpole); portable transit (WiJRDE- 



MANN). 



