The next task that Eurystheus set was the capture of the golden-horned and brazen-hoofed stag of Cerynea, which ran so swiftly that it did not seem to touch the ground. Hercules pursued the stag for many miles, but was unable to overtake it until he drove it into the cold regions of the north, where its fleetness was hindered by the great drifts and the ice-covered ground. Finally the stag ran into a deep snow bank, and so Hercules captured it and took it home in triumph.
The fourth labor to which Hercules lent his great strength was the killing of a wild boar that haunted Mount Erymanthus in Arcadia. While on this expedition, the hero was attacked by the centaurs, and when he shot at them with his poisoned arrows, one of the deadly missiles flew far and struck his loved tutor Chiron, who was galloping toward the combatants, hoping to settle the quarrel peaceably. When Hercules saw Chiron fall, he rushed to his side and tried to stanch the fatal wound; but the dying centaur knew that his end had come, and sorrowfully bade the hero farewell. To reward Chiron for his long service, the gods transferred him to the heavens as the constellation Sagittarius.
Hercules was next sent to kill the flock of fierce birds whose cruel beaks and sharp talons made havoc in the country around Lake Stymphalus. The foul mist that rose from the stagnant water over which the birds hovered was so deadly to breathe that Hercules could hardly approach the lake; but with the help of his poisoned arrows he was able to wound the birds at a distance. After hours spent in this pestilent atmosphere he killed the entire flock and returned to the court of Eurystheus to report his success.
The most unpleasant of all Hercules's labors was the cleaning of the stables where Augeas, king of Elis, kept his herd of a thousand oxen. These stables had not been cleaned for thirty years; and when Hercules caught one glimpse of the filth within them, he felt that this was too degrading a task for him to undertake. But the work had to be done; and since he could not put his hand to anything so foul, he looked about for some other means to accomplish the labor. Not far from the stables flowed two rivers, the Peneus and Alpheus, and these Hercules turned out of their courses and made them rush through the filthy building until every part of the stables of Augeas was washed perfectly clean. Then he restored the rivers to their former beds, and returned home to report this task fulfilled.