every day a vulture came to prey upon his body, and at night the wound would heal, so that it was ever to suffer again. It was a bitter penalty for so noble-hearted a rebel, and as time went by, and Zeus remembered his bygone services, he would have made peace once more. He only waited till Prometheus should bow his stubborn spirit, but this the son of Titans would not do. Haughty as rock beneath his daily torment, believing that he suffered for the good of mankind, he endured for years.
One secret hardened his spirit. He was sure that the empire of Zeus must fall some day, since he knew of a danger that threatened it. For there was a certain beautiful sea-nymph, Thetis, whom Zeus desired for his wife. (This was before his marriage to Queen Juno.) Prometheus alone knew that Thetis was destined to have a son who should be far greater than his father. If she married some mortal, then, the prophecy was not so wonderful; but if she were to marry the King of gods and men, and her son should be greater than he,