€30 EEPORTS OF ASTEONOMICAL OBSERVATOEIES. 



Mrs. Anna Winlock, 

 Mrs. R. T. EoGERS, 

 ^Y. V. Brown, 



A. W. Cutler, 



J. Rayner Edmunds, 



B. PiCKMANN Mann, ' 

 William A. Rogers, 



Arthur Searle, 



Frank Waldo, 



O. C. Wendell. 

 Annexed to Harvard College ; projected in 1810; ground acquired in 

 1827; instruments set up in 1839; a central structure, with a great dome, 

 two wings, two i^avilions, surmounted by domes at the extremities of 

 the wings. Here it was that G. P. Bond discovered in 1818 the seventh 

 satellite of Saturn {Hyperion)^ and in 1850 the dusky interior ring inside 

 the bright rings of that planet. This observatory possesses one of W. 

 C Bond's chronograi^hs, mounted in 1849, and an equatorial of 20^ 

 inches (0™.G8) aperture. 

 Instruments : 



(a) Meridian circle: makers, Troughton & Simms (glasses by Alvan 

 Clark & Sons) ; diameter of circles, 36 inches ; divided to 5' ; each cir- 

 cle read by 4 microscopes to O'M; aperture of objective, 8^ inches: 

 for observations of the sun, aperture employed, 8^ inches; magnifying 

 X)ower ordinarily employed, 300 to 350 diameters, (a') East transit cir- 

 cle, by Troughton & Simms; diameter of circles, 48 inches; divided to 

 5'; each circle read by 4 microscoijes to 0".2; aperture of objective, 

 44 inches. 



(b) Meridian transit instruments : one made by Herbst, of Pulkowa; 

 aperture, 2| inches ; magnifying power, up to 200 diameters. {!)') Large 

 photometer, mounted in the meridian, for comparing images of stars 

 during transit. 



(c) Equatorial instruments : one made by Merz ; aperture of objective, 

 15 inches ; magnifying j)owers of eye-pieces, 100 to 2000. [c') West equa- 

 torial, by Alvan Clark & Sons ; aperture, 5^ inches. 



{d) 8x)ectroscopcs : three, described in vol. viii of the Annals of the 

 Observatory. 



{c) Photometers and other subsidiary apparatus : One Zollner i)hoto- 

 meter, and several photometers of other kinds. 



(/) Ghronofiraphs : two, spring governors, by W. BoND & Son; one 

 small barrel chronograph. 



{g) Clocks: one mean time; maker. Bond, 394: one sidereal; makers, 

 Frodsham, 1327; Bond, 312. 



(h) Chronometers: two sidereal; makers, Frodsham, 3451; Bond, 

 230; one thermometric chronometer, Frodsham, 3424. 



(i) Miscellaneous : Comet-seeker and other small telescopes and appa- 

 ratus. 



