x THE STARRY HEAVENS 423 
the smaller one of the two, the larger being 
red, orange, or yellow. One of the most 
exquisite of these is 8 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 Lyre 
there are two, each again being itself double. 
