a sphere, and that Asia might be reached by sailing westward from Europe.
He laid plans for explorations, and, in 1474, communicated them to the learned Florentine cosmographer, Paul Toscanelli, who gave him an encouraging answer, and sent him a map constructed partly from Ptolemy's and partly from descriptions of Farther India by Marco Polo, a Venetian traveller who told of Cathay (China) and Zipango (Japan) in the twelfth century.
In 1477, Columbus sailed northwest from Portugal beyond Iceland to lat. 73°, when pack-ice turned him back; and it is believed that he went southward as far as the coast of Guinea.
Unable to fit out a vessel for himself, it is stated that he first applied for aid, but in vain, to the Genoese.
With like ill-success he applied to King John of Portugal, who favored his suit, but priests and professors interposed controlling objections.
The King, however, sent a caravel ostensibly with provisions for the Cape Verde Islands, but with secret instructions