432 ASTRONOMICAL OBSEEVATORIES. 



Directors : J. A. voN Segner, 1735. 

 J. Tobias Mayer, 1754. 

 a. M. LoRNiTZ, 1702, 

 A. G. Kastner, 17G4. 

 K. F. VON Seyffer, 1800. 

 0. F. Gauss, 1807. 

 Dr. E. F. W. Klinkerfues, 18G6. 

 Dr. W. SCHUR. 



Fouuded iu 1731, at the same time with the university, and located 

 ill one of the round towers of the ancient fortification, around which 

 was built an exterior gallery. In 1811 the observatory was transferred 

 to a more suitable spot outside the southern gate- way of the town. This 

 new building is on the plan of a rectangle, with the longer sides facing 

 east and west. An addition is made by wings to the north; a cupola 

 surmounts the central vestibule, and a terrace encircles the whole struc- 

 ture. In 1818 the first meridian circle ever made and mounted in Euroj^e 

 was placed there. 



Instruments : 



{a) Meridian circles : One made by Eepsold, sr,, of Hamburg; diam- 

 eter of circle 3^ feet, divided to 5' ; read by two microscopes to 1" ; ap- 

 erture of objective 4-J inches (114"""); magnifying power ordinarily em- 

 ployed, 9G diameters: one made by Eeichenbach, of Munich; diame- 

 ter of circle 3 feet ; divided to 3' ; read by four microscopes to 0.24" ; 

 aperture of objective 4^ inches (lOO*""') ; magnifying i30wer ordinarily 

 employed, 50 diameters. 



• {h) 3Ieridi(m transit instrument : Maker, EEiCHENEAcn, of Munich ; 

 aperture, 4 J inches (110'""') ; magnifying power, 75 diameters; (&') one 

 portable, maker, Ertel, of Munich. 



(c) Equatorial instrument : Maker, Frauenhofer, of Munich ; aper- 

 ture of objective, 2.9 inches (74'"™); magnifying power of eye-piece, 75. 

 (c') Five telescopes : makers, 1st, Merz, of Munich ; 6 feet long, aper- 

 ture 5 inches ; 2d, Steinheil, of Munich ; 5 feet long, aperture 4 inches; 

 3d, DOLLOND, of Munich; 4 feet long, aperture, 3i inches; 4th, Dol- 

 LOND, of Munich ; 3 feet long, aperture 3 inches ; 5th, Plossl, of Vi- 

 enna ; 28 inches long, aperture 2^ inches. Three comet-seekers : makers, 

 1st, Merz, of Munich ; inches aperture ; 2d, Merz, of Munich ; 3 

 inches aperture; 3d, Voigtlander, of Brunswick; 2^ inches aperture. 



{d) Spectroscope : By Merz, of Munich. 



(/") Chronograph: By Ausfeld, of Gotha. 



{g) Cloclcs: One mean time; maker, CastenS; two sidereal: makers, 

 1st, IlARDY, of London; 2d, Shelton. 



(li) Chronometers: Four mean time; makers, 1st, Berthoud ; 2d, 

 Sackmann ; 3d and 4th, Knoblich ; 5th, HARDY ; sixtieth part of a 

 second. 



(i) Miscellaneous: Heliometer by Frauenhofer, of Munich; theodo- 



