But the influence of revived classical information on geographical matters was keenly felt; and the idea of a direct westerly passage to India was suggested, not only by Portugal's monopoly of the Cape route, but by classical authority, generally accepted by the best geographers of the time. The _Imago Mundi_ of 1410, already mentioned, embodying Roger Bacon's arguments that the Atlantic washed the shores of Asia and that the voyage thither was not long, was a book carefully studied by Columbus. Paul Toscanelli, a Florentine physicist and astronomer, adopting and developing this theory, sent in 1474 to Alfonso V of Portugal a map of the world in which he demonstrated the possibilities of the western route. The distance round the earth at the equator he estimated almost exactly to be 24,780 statute miles, and in the latitude of Lisbon 19,500 miles; but he so exaggerated the extent of Europe and Asia as to reduce the distance between them by an Atlantic voyage to about 6500 miles, putting the east coast of China in about the longitude of Oregon. This distance he still further shortened by locating Cipango (Japan) far to the eastward of Asia, in about the latitude of the Canary Islands and distant from them only 3250 miles. With all these opinions Columbus was familiar, for the list of his library and the annotations still preserved in his own handwriting, show that he was not an ignorant sailor, nor yet a wild visionary, but prepared by closest study for the task to which he gave his later years. His earlier career, on the other hand, had supplied him with abundant practical knowledge. Born in Genoa, a mother city of great seamen, probably in the year 1436, he had received a fair education in Latin, geography, astronomy, drafting, and other subjects useful to the master-mariner of those days. He had sailed the Mediterranean, and prior to his great adventure, had been as far north as Iceland, and on many voyages down the African coast. Following his brother Bartholomew, who was a map-maker in the Portuguese service, he came about 1470 to Lisbon, even then a center of geographical knowledge and maritime activity. Probably as early as this time the idea of a western voyage was in his mind.