55 



'in the space of seventy years have moved upwards of five minutes of 

 space. 



The extreme irregularity of the proper motion of the Stars as far 

 as situation and magnitude are concerned, may be remarked in all 

 parts of the Heavens, but it is particularly deserving of notice with 

 respect to the Stars near a Aquilae. The Star y Aquilee of 2.3 

 magnitude, appears to have none or a very small proper motion. 

 The four small Stars of the 6th and 7 th magnitudes recently ob- 

 served also appear fixed, while a Aquilae has a secular motion of 50" 

 in right ascension, and 40" in declination. The Star (2 Aquilae, now 

 only of the third magnitude has only a very small motion in right 

 ascension, but in declination it has a secular motion of about 43" 

 receding from the Pole by this quantity, while a Aquilse approaches 

 the Pole by nearly an equal quantity. Again, according to the ob- 

 servations of Messrs. Herschel and South compared with those of Sir 

 William Herschel, a Star of the lOth magnitude distant from a 

 Aquilae only about 2^ minutes, moves more rapidly than a, but in 

 nearly the same direction. The exactness of the determination of 

 the proper motion of a Aquilse itself is now beyond all doubt. The 

 present observations have confirmed the former conclusions of 

 Maskelyne and Piazzi. 



On more closely examining the right ascensions of the Pole Star, 

 as deduced at different periods by several Astronomers, and more 

 particularly those deduced by Mr. Bessel from Dr. Bradley's ob- 

 servations, I have satisfied myself that my former arguments for 

 shewing that this Star has been without proper motion for many 

 years past, are not sufficient. — The discordances of the observed 

 and computed right ascensions cannot be attributed wholly to the 

 errors of observation. This materially alters several of the con- 



VOL, XV. K 



