206 Trees, Stars, and Birds 



Sirius is, nevertheless, one of the nearest stars. If 

 the others were no farther away, many of them would 

 appear much brighter than Sirius. Not all the faint 

 stars, however, owe their dimness to their great dis- 

 tance, for they differ much in actual size and brilliancy. 

 Around Sirius revolves, in a period of slightly more 

 than 50 years, a star which can be seen only with a 

 large telescope. For years at a time it is so near Sirius 

 that even large telescopes do not enable astronomers 

 to distinguish it. In 1916 it was at its farthest from 

 Sirius. It will be visible with a large telescope for quite 

 a number of years. 



Like the moon, Sirius has been an object of supersti- 

 tion. In the latter part of summer it rises just before 

 the sun, and the ancients associated the approach of 

 the sun to the Dog Star with the season when malaria 

 and some other diseases were prevalent. They sup- 

 posed that in some way the Dog Star exerted an evil 

 influence on health, and even yet we hear of the "dog 

 days." How many other absurd notions have been 

 held without any better reason than this ! 



The Little Dog. The Hunter has another dog, Canis 

 Minor, whose bright star, Procyon, is east of the shoul- 

 ders of Orion and so appears later above the horizon. 

 It rises 15 or 20 minutes before Sirius, from which 

 it is about 20 degrees northeast. It is nearly the 

 same distance east of Betelgeuse, so that the three are 

 at the corners of an approximately equilateral triangle. 

 Not nearly so bright as Sirius, it is, nevertheless, one 

 of the brightest stars in the heavens, and, like Sirius, 

 one of the nearest to us. In 1896 Procyon was dis- 



