But Prometheus loved earthly folk, and thought that they had been children long enough. He was a mighty workman, with the whole world for a workshop; and little by little he taught men knowledge that is wonderful to know, so that they grew out of their childhood, and began to take thought for themselves. Some people even say that he knew how to make men,--as we make shapes out of clay,--and set their five wits going. However that may be, he was certainly a cunning workman. He taught men first to build huts out of clay, and to thatch roofs with straw. He showed them how to make bricks and hew marble. He taught them numbers and letters, the signs of the seasons, and the coming and going of the stars. He showed them how to use for their healing the simple herbs that once had no care save to grow and be fragrant. He taught them how to till the fields; how to tame the beasts, and set them also to work; how to build ships that ride the water, and to put wings upon them that they may go faster, like birds. With every new gift, men desired more and more. They set out to see unknown lands, and their ambitions grew with their knowledge. They were like a race of poor gods gifted with dreams of great glory and the power to fashion marvellous things; and, though they had no endless youth to spend, the gods were troubled. Last of all, Prometheus went up secretly to heaven after the treasure of the immortals. He lighted a reed at the flame of the sun, and brought down the holy fire which is dearest to the gods. For with the aid of fire all things are possible, all arts are perfected. This was his greatest gift to man, but it was a theft from the immortal gods, and Zeus would endure no more. He could not take back the secret of fire; but he had Prometheus chained to a lofty crag in the Caucasus, where 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.