ASTEONOaiY. 195 



3. "The effect of irradiation and its variations on the apparent scmi- 

 dlametcr of the Moon. 



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

 irregularities on its limb. 



5. "The real libration of the Moon by a method independent of the 

 errors caused by abnormal variations in the apparent semi diameter of 

 the Moon. 



Bosiccll Ohservatorij. — A new observatory at Doano College, Crete, 

 N'ebr., has been recenily erected, and is now being suppbed witii 

 astronomical instruments. The equatorial telescope has an object-glass 

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

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

 observatory is being equii)ped, has already secured a Uuffand Burger 

 transit instrument, a Howard meantime clock, a Sewell break-circuit 

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

 paratus. 



The building and instruments have cost about $7,000. 



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

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

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

 gine is now employed to turn the dome covering the- great telesco[)e. 

 The Pepsold 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, (I) the 

 Pons-lirooks comet, the changes in the structure of whicb were not re- 

 markable; (2) diiiicult double stars, thirty two new objects of this class 

 having been discovered by Professor Hough ; (3) the planet Jupiter. 

 the principal objects of interest being the great red spotlirst noticed in 

 1878, and which has maintained its size, sliajjc, and outline with very 

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

 gradual ch-ilt in latitude from year to year, and the equatorial while 

 spots, which, with the envelope they aie 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 difficult 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. \V. Buruham has con- 

 tinued his observations of double stars with the great telescope. {The 

 Nati-on.) Professor Hough is experimenting with a printing chrono- 

 grajjh. 



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

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

 astronomical instruments of his private observatory on Second avenue, 

 H« follows : A 13-inch equatorial telescope with mounting and clock- 



