33^ Mr. South's re-examination of the apparent distances 



No. XI. R. A. ii*' 9" ; Decl. 32° 33' N. 



f Ursae majoris ; I. 2 ; H. andS. 122. 



continued. 



Mean Result. 



Position 25* 28' sp (^5 Obs.) ; Epoch 1825.22 ; 



Distance 2".442 (15 Obs) ; Epoch 1825.25. 



In taking the mean the distances of March 20 are rejected ; 

 if not rejected, the mean of the 25 observations will give 

 distance 2". 2 73, 



Nothing can be more satisfactory than the confirmation 

 these observations afford of the rapid motion ascribed to this 

 remarkable star. In the interval of 1.97 year since the 

 Epoch 1823.29 the jnotion has amounted to no less than 

 13° 55' y in the direction npsf, or — 7°.o25 per annum. The 

 sudden diminution of velocity is however not confirmed. 

 Indeed it rested on too short an interval, and on too few ob- 

 servations (for such very close stars) to deserve great confi- 

 dence. We cannot do better than recommend this star for 

 the next 10 or 20 years to the constant and careful measure- 

 ment of astronomers ; nor can we too strongly inculcate here 

 the indispensable necessity of multiplying extremely their 

 measures of position, to eliminate those errors of judgment 

 to which the most experienced observers are liable in mea- 

 sures of this sort. This done, there is no doubt of our arriv- 

 ing at a precise knowledge of the elements and position of 

 the orbit described by each about their common centre of 

 gravity ; and the question of the extension or non-extension 

 of the Newtonian law of gravity to the sidereal heavens — 

 the next great step which physical astronomy has yet to 

 make — will be effectually decided. (H.) 



