40 



ing. Accordingly Mr. Bessel, in his elaborate investigation of the 

 quantity of precession, (Astron. Fundament.) has considered it 

 necessary to use more than 2000 stars, distributed in all parts of 

 the heavens, concluding that the proper motions in opposite di- 

 rections would compensate for each other, and an exact result be 

 obtained. 



Under these circumstances, it evidently is desirable to ascertain 

 with certainty, or by a high degree of probability, any stars that 

 may be fixed, that is devoid of a sensible proper motion. 



The numerous double stars, many of which Sir Wm. Herschel 

 observed upwards of forty years ago, appeared to me likely to fur- 

 nish some information in this respect. The Pole Star particularly 

 occurred for this enquiry. The Pole Star is of the second magni- 

 tude ; and is, as is well known, attended by a small star of the 

 tenth or eleventh magnitude, only to be seen by good telescopes. 

 The distance between these two stars is 1 8 ",7- 



Now one hypothesis is, that the smaller star may have no relation 

 to the larger, except being seen in nearly the same direction, and 

 may perhaps be much more distant from us. Another hypothesis 

 is, that the two stars may be both mutually attracted, and have a 

 relative motion with respect to each other. In submitting these 

 hypotheses to observation, we find that the smaller star appears to 

 remain at the same distance from the larger one that it was forty 

 years ago, when observed by Sir William Herschel. We are not 

 certain that any change of distance has taken place, and also the 

 angle of position of the two stars remains the same within the 

 limits of exact observation. The smaller star precedes the larger, 

 and the angle of position is about 60° S. 



This permanency of distance and of the angle of position makes 

 it probable, that these stars are too remote from each other to be 



