382 ASTRONOMICAL OBSERVATORIES. 



sists of a west rotunda and three additions. It has double brick walls 

 and an air chamber with a space of 6 inches (0.15™) between the walls 



iNSTRUJdENTS : 



[a) Meridian circle: Makers, Troughton «& Sums; diameter of 

 circle, 30 inches; divided to 5'; read bj reading microscopes to 1', and 

 micrometers to single seconds; aperture of objective, 4 inches ; mag- 

 nifying power ordinarily employed, 120 diameters. 



(c) Equatorial instniment : Makers, Alvan Clark & Sons; aper- 

 ture of objective, 9.25 inches ; magnifying jDowers of eye-pieces, 100 to 

 1,200, 20 in number. 



{(1) Spectroscopes: Large 9-prism Clark spectroscope ; seven prism, 

 double acting (equivalent to 13 prisms), fitting equatorial mentioned 

 above. 



(/) Clironograijli : Bond's spring governor. 



{(j) Clocks: One mean time: makers, Utzschneider & Frauenhofer; 

 connected with chronogrnph ; one sidereal ; makers, Utzschneider & 

 Mahler, of Munich ; connected with chronograph. 



(i) Miscellaneous : Comet-seeker, aperture 3.G inches, mounted on 

 large tripod ; small portable telescope, aperture 3 inches ; zenith sector, 

 loaned by Coast Survey, aperture 4 inches ; full set of common meteoro- 

 logical apparatus, including a recording barometer ; sextant by Hardy, 

 of London. 



Hastings, Kew York. 



Private Observatory. 



Longitude from Washington, 12"' 42.7« E. 

 Latitude, 40° 59' 25" K 



Authority for longitude and latitude, U. S. Coast Survey. 

 Director ; Henry Draper. 

 Instruments : 



(&) Meridian transit instrument : Makers, Stackpole & Brother; 

 aperture, 2 inches; niaguifying power, 45 diameters. 



(c) Equatorial instruments : One reflector, 28 inches aperture, made 

 by Henry Draper; [c') one refractor, 11 inches aperture, by Alvan 

 Clark & Sons, with photographic corrector. 



{d) 8;pectrosco;pes : One diffraction, 1 stellar photographic, 1 automatic, 

 etc. 



(f) Chrcnogra^^h : One made by Henry Draper. 



(g) ClocTc : One mean time ; maker, Howard. 



{h) Chronometers : One mean time ; maker, l!s"EGUS : one sidereal ; 

 maker, Negus. 



(i) Miscellaneous : Altitude and azimuth reflector of 15 J inches aper- 

 ture. 



