Note Back to Main Text — Chapter V · THE SEARCH FOR THE INDIES. WESTWARD OR SPANISH ROUTE.

The years between 1474 and 1480 were not favourable for new maritime ventures on the part of the Portuguese government. The war with Castile absorbed the energies of Alfonso V. as well as his money, and he was badly beaten into the bargain. About this time Columbus was writing a treatise on "the five habitable zones," intended to refute the Columbus's speculations on climate. old notions about regions so fiery or so frozen as to be inaccessible to man. As this book is lost we know little or nothing of its views and speculations, but it appears that in writing it Columbus utilized sundry observations made by himself in long voyages into the torrid and arctic zones. His voyage to Guinea. He spent some time at the fortress of San Jorge de la Mina, on the Gold Coast, and made a study of that equinoctial climate.[466] This could not have been earlier than 1482, the year in which the fortress was built. Five years before this he seems to have gone far in the opposite direction. In a fragment of a letter or diary, preserved by his son and by Las Casas, His voyage into the Arctic ocean, 1477. he says:—"In the month of February, 1477, I sailed a hundred leagues beyond the island of Thule, [to?] an island of which the south part is in latitude 73°, not 63°, as some say; and it [i. e. Thule] does not lie within Ptolemy's western boundary, but much farther west. And to this island, which is as big as England, the English go with their wares, especially from Bristol. When I was there the sea was not frozen. In some places the tide rose and fell twenty-six fathoms. It is true that the Thule mentioned by Ptolemy lies where he says it does, and this by the moderns is called Frislanda."[467]