260 HISTORY OF ASTRONOMY. 



glass of four inches clear aperture. Its axis carries a 

 circle of three feet diameter, connected with it by twelve 

 stout conical radii. The circle is graduated upon silver 

 to five minutes, and reads by four microscopes to single 

 seconds. The whole instrument is mounted upon massive 

 cast-iron pillars, which rest upon masonry, and rise five 

 feet above the floor. An opening 18 inches wide is cut 

 through the roof, and extends down the north and 

 south walls to within 30 inches of the floor. In the 

 same room is an excellent sidereal clock by Dent, of 

 London. 



The east wing is fitted up for an office, with fire-place, 

 cases for books, etc. 



Beside the fixed instruments here mentioned, the ob- 

 servatory possesses a portable transit instrument, an 

 achromatic refractor of 7 feet focal length, a reflecting 

 circle of 10 inches diameter, standard barometer, etc. 



The University has a separate building for a magnetic 

 observatory, and possesses a declination instrument and 

 a dipping needle, both made by Gambey, of Paris. 



MR. RUTHERFORD'S OBSERVATORY. 



There is a private observatory, erected in the upper 

 part of the city of New York, corner of Second Avenue 

 and Eleventh-street, belonging to Lew,is M. Eutherford, 

 Esq. It is furnished with a refracting telescope, made by 

 Henry Fitz, of New York. The aperture of the object- 

 glass is nine inches, and its focal length nine and a half 

 feet. It was mounted equatorially, with clock-work, like 



