8 THE BORDERLAND OF SCIENCE. 



definite limits, and that within those limits stars, re- 

 sembling our sun, are distributed with a certain general 

 uniformity. Then it is quite obvious that, if we look 

 towards those parts of the star-system where the limits 

 'are farthest away, we shall see the greatest number of 

 stars, supposing always that our vision reaches to the 

 limits of the system in such direction. So that if we 

 have but a sufficiently powerful telescope to pierce to the 

 very boundary of the star-system, and if we always use 

 the same telescope so as to make sure that we are 

 always dealing with the same range of the heavens, all 

 we need do in order to determine the shape of the star- 

 system is to count the number of stars seen in different 

 directions. Where there are few stars the boundary of 

 the star-system must be relatively near ; where many 

 stars are seen the boundary must be far away. 



Perhaps not a single reader of these pages needs to 

 be told that it was by applying this method which he 

 called star-gauging that Sir W. Herschel was led to 

 the belief that the system of stars is shaped like a 

 cloven flat disc. And I suppose every reader is familiar 

 also with the picture which is introduced into all our 

 books of astronomy to illustrate this theory of the star- 

 system. I have before me, as I write, Sir W. Herschel's 

 own drawing, in the volume of the Philosophical 

 Transactions for the Year 1785, and, after a careful 

 reperusal of the accompanying paper, I cannot wonder 

 that a theory so noble in itself, and presented with the 

 simple grandeur of diction which distinguishes Sir. W. 

 Herschel's astronomical speculations, should have en- 



