The 15th Century came, and with it the fall of Constantinople; and with it, too, in Genoa, that nautical city of Italy, the birth of a child named Christopher Columbus. He grew to manhood and became a sailor, and sailed on voyages here and there, and was wrecked finally on the coast of Portugal. But here was no ordinary man. Thousands of other sailors had had his opportunities, but none of them took so seriously the idea that the world was round. The idea, of course, was not Columbus’s own. It had received some attention for centuries among a few great minds. But Columbus, not content with accepting the shape of the world as a theory, wanted to make the voyage that would prove it. Already, in the previous century, a great stride had been made in seamanship by the introduction of the compass. This appeared mysteriously in Mediterranean waters, from no definitely known direction, but it seems probable that it came, by a very indirect route, from China, where it had been known and used for many years. Probably this introduction of the compass to the Western world was made by the Mohammedans, for they traded as far east as the Persian Gulf—perhaps farther—and natives of India, with whom the Chinese came into occasional contact, often made the voyage from India to Muscat, so that it seems likely that the compass came to Europe by this route. But to return to Columbus. He took his idea to the King of Portugal, and was turned away. From Portugal the penniless sailor turned to Spain, and many times was refused by the monarchs of that country, for they were busy at the time with the final expulsion of the Moors. After several years of unsuccessful petitioning at the Spanish Court, Columbus gave up and started on his weary way to France. But Queen Isabella sent a messenger after him, and he was recalled and told that he could make the attempt to discover the westward route to India with the aid and under the flag of Spain. On August 3, 1492, he sailed from Palos in command of three little ships—three ships that are now more famous than any others that ever sailed the seas; and with these ships—the _Santa Maria_, the _Niña_, and the _Pinta_—he discovered a new world and opened new seas that now are crossed and recrossed constantly by such a fleet of ships as Columbus could never have imagined.