42 



For a Cassiopeae, /3 Aurigae, and /S Cephei, Bradley's observa- 

 tions were not sufficiently numerous to enable me to venture to 

 decide on the question as to them. But fortunately the observations 

 in declinations of Rigel, a Orionis, and « Cygni, are very numerous ; 

 and these stars are three of the fourteen of which the riffht as- 

 censions have been computed from Dr. Bradley's observations by 

 Mr. Bessel, with great skill and labour. The distances of these 

 stars from each other in 1755, 1800, and 1824, seem to leave no 

 doubt that they have been, witli respect to the interval of seventy 

 years, really fixed. 



DISTANCES. 



The distances of the Pole Star from these three stars respectively, 

 might at first lead us to suppose, that although the Pole Star may 

 have no proper motion in declination, it has a small proper motion 

 in right ascension ; but I am inclined, for the present, to attribute 

 the small differences to an inexactness in the right ascension of the 

 Pole Star. Of the three stars, there can be no doubt as to their 

 permanency of position, and on this account they will, I imagine, 

 be considered worthy of the future notice of astronomers. 



By comparing the polar distance of the Pole Star in 1 755 with 

 that in 1819, as given by me in Phil. Trans. 1822, we obtain the 



