Among the motives influencing him to think that he could sail to Cathay by the way of the Atlantic Ocean were the statements of geographical writers. By them it was said “that a great part of the globe had already been travelled over, and there only remained to be discovered and made known the space lying between the eastern limits of India, known to Ptolemy and Marinus, and the West, where are the islands Azores[112] and those of Cape Verd,[113] the most western lands yet discovered.[114] ... He considered that this space, lying between the eastern limits [of India] known to Marinus and the islands of the Cape Verd group, could not be more than a third part of the great circumference of the globe, since Marinus had gone toward the East fifteen hours of the twenty-four into which the circumference of the earth is divided, and therefore to go [still farther eastwardly] to reach the Cape Verd Islands there were nine hours, [of the circumference to be passed over], as it is said that Marinus began his investigations in the West.... He conceived that since Marinus had given in his cosmography an account of fifteen hours or parts of the globe eastwardly, and had not reached the limits of the East, it followed that its bounds must be much beyond, and consequently the farther the land of the East extended eastwardly, the nearer this land was to the Cape Verd Islands in the West, and that if the space were chiefly water it might easily be sailed in a few days, and if it were mainly land it would sooner be discovered by sailing westward, because it would be nearer to the Cape Verd Islands.[115] ... The fifth reason, which induced him to believe that the distance this way was short, was the opinion of Alfragranus and his followers, who make the circumference of the globe much less than all other writers and cosmographers, allowing fifty-six miles and two-thirds to a degree.[116] Whence he inferred that as the entire circumference of the globe was of such an extent, the third part was small, which Marinus left unknown.... And Seneca, in his first book of nature, who considers the knowledge of this world as nothing when compared with that which is acquired in the next life, says a ship may sail in a few days with a fair wind from the coast of Spain to that of India. And if it be true, as some believe, that Seneca wrote tragedies, we may infer that he speaks of the same thing in the chorus of his Medea: ‘Venient annis Saecula seris, quibus Oceanus Vincula rerum laxet, et ingens Pateat tellus, Typhysque novos Detegat orbes, nec sit terris Ultima Thule.’