Then he heard a fearful bellowing issuing from the depths, the earth shook, and great waves hurled themselves upon him and the cliff to which he was fastened. A year ran its course, and when finished, Zeus again dispelled the darkness about the cliff, but with no intention of mitigating Prometheus’ punishment. On the other hand, he determined to make it harder. He sent a vulture who attacked his body and devoured his liver. This torment was renewed daily, for every night his liver grew again. Zeus also vowed that as Prometheus, being a god, could not die, he should hang on the cliffs of Caucasus forever. And thus it happened through many generations of men. At last the spirit of Titan’s son was broken and he longed for peace and freedom. The other Titans who were once overcome by Zeus and hurled into Tartarus, had long regained their freedom. Reconciliation, however, seemed impossible, for Zeus had once vowed he would not send away the vulture and strike off his fetters unless a deity should undertake to descend into dark Tartarus. At this time Heracles (Hercules), a son of Zeus by a mortal, was traversing the world, fighting every monster which was endangering the human race. In his travels he came to Caucasus. To his utter astonishment he saw the son of a god fastened there and asked him why he had to endure such agonies. Thereupon Prometheus told him of his fate and Hercules determined to rescue him. Throwing aside his lion skin and club, and taking a poisoned arrow from his quiver, he shot the vulture, tore his claws from the Titan’s groin, and threw him into an abyss. Then Hercules released him from his chains and conducted him to Zeus. Prometheus unwillingly announced to him that a marriage with the beautiful sea nymph Thetis would be his ruin. The reconciliation, however, was not complete, for Zeus’ vow was not yet satisfied. He gave Prometheus a gold ring in which Hephaestus had set a little stone from the Caucasus. “Promise me always to wear this ring,” said Zeus, “and my vow may be accomplished.” Prometheus took the ring and made the promise. Then Hercules fetched Cheiron, whom he had unintentionally wounded with a poisoned arrow, to the deity. Cheiron, who was suffering unspeakable torments and longed to die, gladly descended into Tartarus. Thus the conciliation was complete. Warned by Prometheus, Zeus married Thetis to a mortal, King Peleus. At once a multitude of lovely sea nymphs came to escort the bride and groom in festal procession. Zeus and the other divinities also joined in the festivities and celebrated the marriage of the beautiful sea nymph. Chapter II Deucalion and Pyrrha