So much for the outposts of the Old World. Of the New World, about the possibility of which Columbus is beginning to dream as he sails the Mediterranean, there was no knowledge and hardly any thought. Though new in the thoughts of Columbus, it was very old in itself; generations of men had lived and walked and spoken and toiled there, ever since men came upon the earth; sun and shower, the thrill of the seasons, birth and life and death, had been visiting it for centuries and centuries. And it is quite possible that, long before even the civilisation that produced Columbus was in its dawn, men from the Old World had journeyed there. There are two very old fragments of knowledge which indicate at least the possibility of a Western World of which the ancients had knowledge. There is a fragment, preserved from the fourth century before Christ, of a conversation between Silenus and Midas, King of Phrygia, in which Silenus correctly describes the Old World—Europe, Asia, and Africa—as being surrounded by the sea, but also describes, far to the west of it, a huge island, which had its own civilisation and its own laws, where the animals and the men were of twice our stature, and lived for twice our years. There is also the story told by Plato of the island of Atlantis, which was larger than Africa and Asia together, and which in an earthquake disappeared beneath the waves, producing such a slime upon the surface that no ship was able to navigate the sea in that place. This is the story which the priests of Sais told to Solon, and which was embodied in the sacred inscriptions in their temples. It is strange that any one should think of this theory of the slime who had not seen or heard of the Sargasso Sea—that great bank of floating seaweed that the ocean currents collect and retain in the middle of the basin of the North Atlantic.