THE CONSTELLATIOKS. 
157 
monster Cerberus in his left hand, in his right a 
club. His left foot is near the five stars that form 
the head of the Dragon, which extends in coils toward 
Cepheus, then back again, winding in between the 
Little Bear on the one side and Bootes and the Great 
Bear on the other. The principal star of Hercules, a 
Fig. 78. —Spectrum of a Herculis, showing that in the atmosphere 
of the star numerous chemical compounds are burning. 
notable double star, is in his forehead. This, with 
five others, forms a winding line extending toward 
the pole. The stars may also be grouped in the shape 
of two adjoining trapezoids. 
The mythological history of Hercules is extensive 
and varied, but he is generally considered to be the 
son of Jupiter and Alcmena. Juno, being jealous of 
him, sent two serpents to destroy him while still in 
the cradle, but he succeeded in strangling them. 
Afterward, by her cunning, she induced Jupiter to 
put him under the command of her son, his half- 
brother, who imposed upon him severe tasks. These 
he successfully performed, and they have become 
known as the “Twelve Labors of Hercules.” 
His death is uncertain. It is believed that his 
wife, having dipped his white robe in the blood of the 
monster Hessus, gave it to him to wear. It clung to 
his body and frightfully irritated him. Being unable 
