ASTRONOMY. 171 



in ISGd-'OS; i)a])ors on tluMiiotioii of the liiiiiir apsides and on the coiu- 

 l);inion of Sirius by ]*i'ofessoi' Colbert; and an illustrated puper on the 

 physical aspect of Jupiter, a catalogue of 20!) new double stars, and a 

 des(;ription of a printing chronograph by Professor Hough. In the 

 course of the two years referred to 130 new double stars were discov- 

 ered and measured. 



In consequence of the dissolution of the University of Chicago the 

 <Jhi<;ago Astronomical Society dismounted their instruments in the 

 early part of 1888, and transferred the care of the observatory to the 

 Northwestern University, at Evanston, Illinois, 12 miles from the busi- 

 ness center of Chicago, about 16 miles north and 3 miles west of the old 

 site, and some 300 feet from the shore of Lake Michigan. The corner 

 stone of a new building, the gift of James B. Hobbs, was laid June 21, 

 1888. The i^lan includes a tower and dome for the 18J-inch equatorial, 

 meridian circle room, library, and about eight rooms for other purposes; 

 the whole to be erected at a cost of $25,000. The approximate position 

 is given: Latitude, -f42o 3'; longitude, 5'' 50'" 12'' west of Greenwich. 



Dem'er. — A new observatory, the gift of Mr. 11. B. Chambei'liu to the 

 University of Denver, is being built, about 7 miles from the city of 

 Denver, at an altitude of 5,000 feet above sea-level. The i)riucipal 

 instrument is to be a 20-incli Clark refractor. Director, Prof. II. A. 

 Howe. • 



Dresden. — Baron von Engelhardt's older observatory was l>uilt in 

 1S77 (latitude, -+-'51o 2' 31"; longitude, 0'' 51'" 53«.3 east of Greenwich), 

 and contain<Ml an 8-inch Grubb e<iuatorial, a 2-inch Cooke transit, and a 

 sidei'eal clock by Kuoblich. The present observatory was built in 1879 

 somewhat nearer the outskirts of Dres<len (latitude, +51^' 2' 19"; longi- 

 tude, 0'' 54'" 54«.7 east of Greenwich). It consists of a three-story tower, 

 the upper story being surmounted by a cylindrical "dome" covering a 

 12-iuch Grubb equatorial. The second floor connects with the transit- 

 room, in which is a "broken-back" transit, by Bamberg, of 2.7 inches 

 aperture. There is also a very complete e(iuipment of subsidiary appa- 

 ratus, (jlocks, chronometers, chronograph, etc. Upon the adjoining roof 

 of the baron's residence is a little coniet observatory arranged for two 

 instruments, one of 0.4 inches aperture and the other of 3.7 inches. The 

 larger instrument, which is similar to the Strassburg comet-seeker, is 

 of somewhat novel construction. The telescope is fasten(Ml by two long 

 arms to the back of a chair so that the eye-end (;omes at a convenient 

 l»osition for the observer; the arum are pivoted to the chair- ba(;k, per- 

 mitting a motion in altitude, while the chair may be rotated in azimuth, 

 so that the astronomer can examine the whole sky ra|)idly and without 

 fatigue. 



The numerous and valuable observations of ociuiltations, ])henomena 

 of .Jupiter's satellites, comets, phnuits, new stars, nebuhe, ami clusters 

 were collected and ])ublishe(l in the latter i)art of 18S0, together with an 

 illustrated description of the observatory and instruments. Similar ob- 



