22 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



3Iimas was, however, only once observed. The accidental 

 error of a difference of right ascension between Japetus and 

 Saturn from a single wire is only d=0,032^; and Professor 

 Hall hopes that, by varying the method of observing during 

 the next opposition, jDOSsible constant errors may be elimi- 

 nated. The number of observations of each satellite is as 

 follows : Japetxis^ 70 ; Titan, 43 ; Hyperion, 40 ; Rhea, 31 ; 

 Dione, 31 ; Tethys, 29 ; Enceladus, 16 ; Mimas, \. 



PROPER MOTIONS OF SOUTHERN STARS. 



Mr. E. G. Stone, Her Majesty's astronomer at the Cape of 

 Good Hope, communicates to the Koyal Astronomical So- 

 ciety a paper on the proper motions of 406 southern stars, 

 which is printed in the Memoirs, vol. xlii., p. 129. After ex- 

 amination, Stone concludes that those of Lacaille's 9V66 

 stars observed at the Cape of Good Hope in 1751-2 with 

 the altitude instruments are available for this purpose, but 

 the places given by the rhomboidal micrometer are not suffi- 

 ciently accurate. 



Of the first class there are 398, but 130 of these are iden- 

 tical with Bradley's stars, so that the material for accurate 

 determinations of proper motions in the Southern hemisphere 

 is less than might have been expected. 



Stone bases his determinations on Brisbane (1825) [for 

 N.P.D. only]; Fallows (1830); Johnson (1835); Henderson 

 (1833); and a MS. reduction of Maclear (1840). The sepa- 

 rate results from each catalogue are exhibited. 



ORBIT OF THE BINARY STAR 7 CORONA ATJSTRALIS. 



The orbit of this star, which is in R. A. 18h. 55m., and 

 south declination 37 18', was investigated by Captain Jacob 

 in 1855 {Mon. Not. B. A. S., vol. xv., p. 208), his orbit being 

 based on twenty-one years of observation. Schiaparelli has 

 lately reinvestigated this orbit, and he finds that Jacob's 

 orbit does not accurately represent the later observations. 

 Accordingly he has deduced the elements which best satisfy 

 the whole series (allowing, however, more weight to the ob- 

 servations since 1852), and finds the period of revolution to 

 be 55.582 years, and the semi-major axis to be 2.400". Schia- 

 parelli's elements agree very closely with observation, and 

 he adds an ephemeris extending to 1882. 38 C, No. 2073,133. 



