, therefore, turned his
thoughts to the practicability of reaching India by sailing to the west. At
this time the rotundity of the earth was generally admitted. The ancients,
whose opinions on the extent and direction of the countries which formed
the terrestrial globe, still retained their hold on the minds even of
scientific men, had believed that the ocean encompassed the whole earth;
the natural and unavoidable conclusion was, that by sailing to the west,
India would be reached. An error of Ptolemy's, to which we have already
adverted, contributed to the belief that this voyage could not be very
long; for, according to that geographer, (and his authority was implicitly
acceded to,) the space to be sailed over was sixty degrees less than it
actually proved to be,--a space equal to three-fourths, of the Pacific
Ocean. From considering Marco Polo's account of his travels in the east of
Asia, Columbus also derived great encouragement; for, according to him,
Cathay and Zepango stretched out to a great extent in an easterly
direction; of course they must approach so much the more towards the west
of Europe. It is probable, also, that Columbus flattered himself, that if
he did not reach India by a western course, he would, perhaps, discover the
Atlantis, which was placed by Plato and Aristotle in the ocean, to the west
of Europe.

Columbus, however, did not trust entirely to his own practical knowledge of
navigation, or to the arguments he drew from a scientific acquaintance with
cosmography: he heard the reports of skilful and experienced pilots, and
corresponded with several men of science. He is said, in a particular
manner to have been confirmed in his belief that India might be reached by
sailing to the west, by the communications which he had with Paul, a
physician of Florence, a man well known at this period for his acquaintance
with geometry and cosmography, and who had paid particular attention to the
discoveries of the Portuguese. He stated several facts, and offered several
ingenious conjectures, and moreover, sent a chart to Columbus, on which he
pointed out the course which he thought would lead to the desired object.

As Columbus was at the court of Lisbon, when he had resolved to undertake
his great enterprise, and, in fact, regarded himself as in some degree a
Portuguese subject, he naturally applied in the first instance to John II.,
requesting that monarch to let him have some ships to carry him to Marco