CHAPTERS ON THE STARS. 323 



in this region the stars are no thicker than elsewhere. In the region 

 from 18h. to 21h. there is an excess of 45 stars having proper motions. 

 Whether this excess is real may well be doubted. It is scarcely, if at 

 all, greater than might be the result of accidental inequalities of dis- 

 tribution. Were the proper motion stars proportional to the whole num- 

 ber, there ought to be 240 within the strip. The actual number is 38 

 less than this. 



It is to be remembered that Auwers's proper motions are not limited 

 to a definite magnitude, as were Boss's, but that he looked for all stars 

 having a sensible proper motion. The question, what proper motion 

 would be sensible, is a somewhat indefinite one, depending very largely 

 on the data. It may, therefore, well be that the small excess of 45 found 

 within this strip is due to the fact that more stars were observed and 

 investigated, and, therefore, more proper motions found. Besides this, 

 some uncertainty may exist as to the reality of the minuter proper mo- 

 tions. 



The conclusion is interesting and important. If we should blot out 

 from the sky all the stars having no proper motion large enough to be 

 detected, we should find remaining stars of all magnitudes; but they 

 would be scattered almost uniformly over the sky, and show no tendency 

 toward the galaxy. 



From this again it follows that the stars belonging to the galaxy lie 

 farther away than those whose proper motions can be detected. 



