32 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Tycho Brahe, and subsequently devoted himself to the con- 

 struction of globes, which he made in great perfection, of 

 three different dimensions. His larger celestial globes, in a 

 space near the constellation Cygnus, mention the discovery, 

 in 1600, of a new star in the breast of the Swan. Kepler 

 stated, in 1606, that this star had been discovered by Blaen 

 himself; the date of the discovery was the 18th of August, 

 1600. At that time it was of the third magnitude. It soon 

 after diminished until it became invisible to the naked eye, 

 and only became visible again in 1670, when it again attained 

 a third magnitude, lasting two years ; but faded away, and 

 has not since been observed. Possibly it will ajopear again 

 about 1880. 6 B, LXXXL, 335. 



THEOKY OF THE SATELLITES OF JUPITEK. 



The present predictions in the Astronomical Ephemerides 

 of the phenomena of Jupiter's satellites are based on the 

 tables of Damoiseau, which extend only to 1880. The pre- 

 dictions of eclipses are in error, by the observations of Mr. 

 D.P.Todd, at Amherst College, in 1875 (with a four-inch 

 aperture), by the following amounts : 



I. Satellite; Correction to Tables + 53.0' for a Disappearance; 16 obs. 

 II. " ; " " " + 11.8^ " " ; 8 " 



III. " ; " " " +24.P " " ; 4 *' 



M. Souillart has re-examined, in several memoirs published 

 in Annales Scientifiques de VEcole Normale Stuperieiire (t. ii., 

 l.serie),the theory of these satellites as delivered in the Jf/e- 

 canique Celeste, making use, however, of a different process 

 from the one followed by Laplace. His results have in gen- 

 eral confirmed the previous theory. New researches by M. 

 Souillart lead to some important modifications in the values 

 of Laplace's coefiicients. These latest researches will soon 

 be published with others, so as to furnish a complete theory 

 of the motions of Jupiter's satellites, together with tables, 

 now so much needed. 6 JB, March 27, 1876, 728. 



ON THE PARALLAX OF 1830 GKOOMBRIDGE. 



The star 1830 Groombridge, which is so famous on account 

 of its extremely large proper motion, has for forty years been 

 a favorite subject of measurement for the determination of 

 its parallax. The most recent observations of this charac- 



