13C) PROGRESS OF ASTRONOMY FOR 1891 AND 1892. 



the tlieory of a sensible orbital motion of the bii!>;lit component, and 

 the theoretical parallax, suggested by Mr. Chandler. 



Yerkes (University of Chicago): Hale. — Through the munificence 

 of Mr. Charles J. Yerkes, of Chicago, tlie University of Chicago is to 

 have an astronomicar observatory of the first class. No definite limit 

 has been assigned to the expenditure contemplated, but it is intimated 

 that the eiiuipment shall be equal to any in existence. The principal 

 instrument will be a 40-inch refractor, the disks for which were made 

 some years since for the University of Southern California. 



The remainder of the equipment is still undetermined, but it will 

 probably include a IC-inch lefractor, 12-iuch "'twin " equatorial with 

 visual and photographic objectives, 6-inch meridian circle, and 20-inch 

 siderostat. 



Zurich: B. Wolf. — Sun-spot observations; observations for deter- 

 mining the variation of latitude; time service. 



ASTR( )NOMIC AL INSTRUMENTS. 



Brash('ar-}{asii)i(/.s objectives. — Three large object glasses recently 

 made by Brashear are of more than ordinary interest, as they have 

 been ground by Prof. Hastings' formula. They are the 16-inch of the 

 Goodsell Observatory, the 12.2 of the Ladd Observatory, and the 12-inch 

 of the Kenwood Physical Observatory. The crown glass was obtained 

 from Mantois, of Paris, and the fiint from tipt' o])tical works at Jena, 

 Germany. 



A new instrument has been devised by A. Becik, called a '^ ISTadir- 

 Instrument," for the determination of time and latitude by observation 

 of the transits of stars over a circle whose pole is the zenith. The in- 

 strument is adjusted for a circle of 60<^ zenith distance. 



To amateurs a series of articles on the ''Adjustment of a small Equa- 

 torial," in the Journal of the British Astronomical Association (Feb- 

 ruary, 1892), by Mr. Maunder, will undoubtedly prove of interest and 

 value. 



MISCELLANEOUS. 



Prizes. — The Lalande prize of the Paris Academy for 1891 was 

 awarded to M. C Bigourdan for the work he has undertaken and 

 partly carried out, of micrometrically measuring all the known nebu- 

 he, about six thousand in number, observable at Paris ; this will be a 

 first step to obtaining some knowledge of their proper motions, and 

 ultimately, perhaps, of their distances from the sun. No memoir was 

 presented to the Academy on the special subject proposed for the 

 Damoiseau prize, " To perfect the theory of the inequalitTies of long 

 periods caused by the planets in the motion of the moon." It was, 

 therefore, proposed again for 1892, and its value fixed at 1,000 francs. 

 Prizes were, however, adjudged, for their ] Janetary and cometary inves.- 



