ASTRONOMY. 195 



3. "The effect of irradiation aud its variatioDS on the apparent semi- 

 dlanieter of the Moon. 



4. "The systematic variation of the apparent place produced by the 

 irreguhirities on its limb. 



5. "The real librntiou of the 2Ioon by a method independent of the 

 errors caused by abnormal variations in the apparent semi-diameter of 

 tlie Moon, 



BoswcU Observatory. — A new observatory at Doane College, Crete, 

 -Nebr., has been recently erected, and is now being supplied with 

 astronomical instruments. The equatorial telescope has an object-glass 

 of"8 inches aperture, made by the Clarks. The mounting is furnished 

 at jMadisou, Wis. Prof. G. D. Swezey, under whose directions the 

 observatory is being equi])i)ed, has already secured a Buff and Burger 

 transit instrument, a Howard mean-time clock, a Sewell break-circuit 

 chronometer, a Seth Thomas clock, and a set of meteorological ap- 

 paratus. 



The building and instruments have cost about $7,0U0. 



Chicago Observatory. — From the annual report of the director of the 

 Dearborn Observatory at Chicago, Prof. G. W. Hough, it appears 

 that the chief instruments have been kept in constant use. A gas en- 

 gine is now employed to turn the dome covering the great telescope. 

 The Eepsold meridian circle is used only for observations connected 

 with the time-service. The great telescope, of 18 inches aperture, has 

 been exclusively employed in the observation of a few objects, (1) the 

 Pons-Brooks comet, the changes in the structure of which were not re- 

 markable ; (2) difticult double stars, thii'ty-two new objects of this class 

 havmg been discovered by Professor Hough ; (3) the planet Jupiter, 

 the principal objects of interest being the great red spot first noticed in 

 1878, and which has maintained its size, shape, aud outline with very 

 slight change, the great equatorial belt, which has been subject to 

 gradual drift in latitude from year to year, and the equatorial white 

 spots, which, with the enveloi)e they are situate in, move with a velocity 

 of 2G0 miles per hour, thus revolving about the planet in a month and 

 a half; (4) the planet Saturn, with negative results so far as markings 

 on or subdivisions of the rings were concerned ; and (5) the satellites of 

 Uranus, which were such difticult objects as not to have been frequently 

 seen. Six drawings of Jupiter^s disk were made, four of which are 

 printed in the report. As heretofore, Mr. S. W. Burnham has con- 

 tinued his observations of double stars with tlie great telescope. {Tl(c 

 Nation.) Professor Hough is experimenting with a printing chrono- 

 graph. 



Columbia College Observatory. — Mr. Lewis M. Rutherford, of New York 

 City, has presented to the trustees of .Columbia College the valuable 

 astronomical instruuients of his private observatory on Second avenue, 

 as follows ; A 13-inch equatorial telescope with mounting and clocU- 



