36 OUR PHYSICAL WORLD 



forming a triangle (Triangulum) . The former two are in Aries, 

 a constellation in which alpha is a conspicuously bright star 

 (Fig. 20). 



Cancer, the Crab, is made up of inconspicuous stars, but Leo, 

 the Lion, is easily recognized. When Castor and Pollux are on 

 the meridian about the middle of March, there is a sickle-shaped 

 group of stars to the east of them and about a third of the way 

 to the horizon that marks the Lion. Regulus, the brightest star 



FIG. 20. Aries, the Ram 



of the constellation, is at the end of the handle of the sickle. 

 Castor, Sinus, and Regulus make a triangle-shaped figure (see 

 Fig. 21) that is the counterpart of the triangle formed by Castor, 

 Sirius, and Aldebaran. Regulus is also at one corner of a nearby 

 isosceles triangle with one of the pointers of the Dipper and 

 Denebola, another bright star of Leo, at the other corners. Leo 

 represents the Nemean lion, the fight with which formed the 

 first of the celestial labors of Hercules (Fig. 22). 



Still later in the spring, about 8 : 30 P.M. in the last of April, 

 when the pointers of the Dipper are on the meridian, the next 



