MoNCK — On Star' Distribution. 



497 



smaller average distance of the brighter stars. In M. Flam- 

 marion's Introduction to his Star Atlas I find a table of sixty stars 

 having the greatest proper motion observed up to that period, ar- 

 ranged in order of magnitude ; and, comparing these with the 

 total number of stars of each magnitude as given by Dr. Ball, I 

 ascertained what per centage of the stars of each magnitude fell 

 into this selected batch of sixty. The result is as follows :— 



Here, again, no doubt, the proper motions of the stars of the 

 first magnitude have been examined more carefully than those of 

 the fainter stars ; and, in the case of some of the latter, even since 

 the publication of M. Flammarion s Table, large proper motions 

 have been discovered. But I think it very unlikely that the stars 

 of the first magnitude will be displaced from the position which 

 they occupy ; for, the last of the four which are included in M. 

 Flammarion's list — Procyon — is the thirty- eighth in the Table; 

 and it will therefore be necessary to discover twenty-two fainter 

 stars with larger proper motions to exclude him from the leading 

 sixty. But even if we lost both Sirius and Procyon, the two 

 stars which there is no chance of displacing — a Centauri and Arc- 

 turus — would secure the first place for the stars of the first magni- 

 tude, which would still contribute ten per cent, of their total 

 number to the list in question. 



I proceed to mention some other indications of comparative 

 nearness, which, so far as I am aware, are almost exclusively con- 

 fined to the brighter stars — that is, to the stars of, say, the first 

 four magnitudes. One of these consists of two well-separated 

 stars, one of which nevertheless revolves round the other in a 

 moderate period. Such a star, for instance, is ^ in the Grreat Bear, 

 where the two stars can be easily separated, while the period of 

 revolution is only about sixty years. Sirius is in the same position, 

 though his companion is so faint that a powerful telescope is neces- 

 sary, not to separate the stars, but to detect the smaller one. We 



2U2 



