X THE STAREY HEAVENS 423 



the smaller one of the two, the larger being 

 red, orange, or yellow. One of the most 

 exquisite of these is /3 Cygni, a Double Star, 

 the larger one being golden yellow, the smaller 

 light blue. With a telescope the effect is very 

 beautiful, but it must be magnificent if one 

 could only see it from a lesser distance. 



Double Stars occur in considerable numbers. 

 In some cases indeed the relation may only be 

 apparent, one being really far in front of the 

 other. In very many cases, however, the 

 association is real, and they revolve round 

 one another. In some cases the period may 

 extend to thousands of years ; for the distance 

 which separates them is enormous, and, even 

 when with a powerful telescope it is indi- 

 cated only by a narrow dark line, amounts 

 to hundreds of millions of miles. The Pole 

 Star itself is double. Andromeda is triple, 

 with perhaps a fourth dark and therefore 

 invisible companion. These dark bodies have 

 a special interest, since it is impossible not 

 to ask ourselves whether some at any rate 

 of them may not be inhabited. In e Lyrse 

 there are two, each again being itself double. 



