According to official documents, Ch. Columbus traveled to coasts of the New World for four times - in 1492-1493, 1493-1496, 1498-1500 and 1502-1504 - and thought that he had discovered Asia du-ring all travels. These assumptions may be met in all sources. Besides it, there is another skeptic conception too (since the middle of XVI century). The French physician Jan Fernell, who was interested in astronomy, wrote that, the length of the Earths outline was 39816 km and its radius was 6337 km. It means that, Toscanelli had made a mistake. According to his calculations, the length of the Earths outline was 29000 km.Thats why, Columbus didnt agree with the report of the Floren-tine scientists and used measurement of the greek scientist Eratosthene sand geographical coordinates of the Earth offered by Tusi. Columbus started his travel very decidedly and it didnt happen by the accident. He had learned a lot of things after analyzing scientific works of Nasiraddin Tusi including his map. Tusi wrote that, there was a very large land area in the west of the Old World, on the other side of the ocean.