Nevertheless, as a result of these travellers' reports, the traditions of earlier times and the knowledge of the nearer East possessed by traders were supplemented and popularized. The journeys of the travellers of the later thirteenth and the fourteenth centuries were a veritable revelation to Europe of the condition of Tartary, Persia, India, China, and many intervening lands. Especially strong was the impression made by the reports about China and Japan. The land of the Seres, lying on the border of the eastern ocean, had indeed been known to the ancients, and mentioned by tradition as the source from which came certain well-known products; but under the name of Cathay, which Marco Polo and his contemporaries gave to it, it attained a new and strong hold on men's imaginations. Its myriad population, its hundreds of cities, its vast wealth, its advanced civilization, its rivers, bridges, and ships, its manufactures and active trade, the fact that it was the easternmost country of Asia, washed by the waters of the external ocean—all made Cathay a land of intense interest to the rising curiosity of thirteenth-century Europe. [Footnote: Pigeonneau, "Histoire du Commerce de la France," II, 12, etc.] Similarly the great island of Cipangu, or Japan, lying a thousand miles farther to the eastward, though never actually visited by Marco Polo, and described by him with a vague and extravagant touch, was of equally keen interest to his readers, as were the "twelve thousand seven hundred islands" at which he calculates the great archipelagoes which lie in the Indian Ocean and the Pacific.
It was his accounts of "the province of Mangi," the cities of Zaiton and Quinsay, "the Great Khan," "the island of Cipangu," and of their vast wealth and active trade that took special hold on the mind of Columbus. His copy of Marco Polo may still be seen, its margins filled with annotations on such passages, made by the great navigator; [Footnote: Vignaud, "Toscanelli and Columbus," 95.] and it was to these that his mind reverted when he had discovered in the West Indies, as he believed, the outlying parts of the Khan's dominions. [Footnote: "Columbus's Journal," October 21, 23, 24, 26, 30, November 1, etc.] To the westward also ancient knowledge was reacquired and made clearer. The "Fortunate Isles" were rediscovered and identified as the Canaries by the Italian Lancelot Malocello in 1270 [Footnote: Beazley, Hakluyt Soc, "Publications," 1899, lxi, lxxviii.], then forgotten and rediscovered in 1341 [Footnote: Ibid, lxxx; Peschel, "Zeitalter der Entdecktungen," 37.] by some Portuguese ships, manned by Genoese, Florentines, Castilians, and Portuguese. In 1291 Tedisio Doria and Ugolino Vivaldi, Genoese citizens, equipped two galleys and sailed out through the Straits of Gibraltar and then to the southward, with the object of reaching the ports of India, but were never heard of again [Footnote: Peschel, "Zeitalter der Entdeckungen," 36.]. Both the Madeira Islands and the Azores became known as early as 1330, though perhaps only in a shadowy way, and were visited from time to time later in the fourteenth century, before they were regularly occupied in the fifteenth [Footnote: Nordenskiold, "Periplus," 111-115; Major, "Prince Henry the Navigator," chaps, v., viii., xiv.].
Through the thirteenth and fourteenth centuries, therefore, thanks for the most part to Italian travellers, substantial gains were made in exactitude and clearness of knowledge of the Old World. Though the bounds of geographical knowledge were not carried much farther, and less than one-fourth of the surface of the globe was as yet known to Europeans, within these bounds knowledge became far more clear.
Ignorance and superstition were still abundant; a mythical kingdom of Prester John was believed by one geographer to exist in Africa, by another to be situated in India, and by still another to be in China; the Atlantic was still dreaded by some as the dark, unknown limit of the world; ignorant men may still have believed that the sea boiled at the equator, and that men with dogs' heads and other monsters had each its own part of the earth; but Italians of any education, especially those acquainted with the writings of their countrymen, must have been quite free from such mediaeval notions. By the year 1400 scientific information, critical habits of thought, and an interest in all forms of knowledge had reached in Italy a high degree of development and were fast spreading through Europe.
The theory that the earth was round was familiar to the Greeks and Romans, and was supported in the Middle Ages by the great authority of Aristotle. [Footnote: Aristotle, De Ccelo, II., 14.] The only difficulties lying in the way of an acceptance of this view through the mediaeval period were, in the first place, the mental effort required to conceive the earth as round when its visual appearance is flat; and, secondly, the opposition of churchmen, who interpreted certain texts in the Bible in such a way as to forbid the conception of the earth as a sphere. Yet neither of these influences was strong enough to prevail over the opinions of the majority of learned men. To them the earth was round, as it was to Aristotle, Ptolemy, and other ancients. [Footnote: Ruge, Zeitalter der Entdeckungen.] The ball which the Eastern emperors carried as an emblem of the world-wide extent of their rule, and which was borrowed from them by various mediaeval potentates, had probably not lost its meaning. Dante, in the Divina Commedia, not only plans his Inferno on the supposition of a spherical earth, but takes for granted the same conception, on the part of his readers. [Footnote: Inferno, canto 34, lines 100-108.]
The conception of the sphericity of the earth was really a matter of mental training. In the fifteenth century those who had gained this knowledge were fewer than in modern times, but the class who did so believe were no less sure of it. Astronomers, philosophers, men of general learning, and even navigators and pilots were quite familiar with the idea and quite in the habit of thinking of the earth as a sphere. In all probability Columbus represented the beliefs of his class, as well as his own, when he said, "I have always read that the world, comprising the land and the water, is spherical, as is testified by the investigations of Ptolemy and others, who have proved it by the eclipses of the moon and other observations made from east to west, as well as by the elevation of the pole from north to south." [Footnote: Hakluyt Soc., Publications, Hist. of Columbus—Third Voyage, II., 129.] Opposition to voyages westward was based rather on the probability of the enormous size of the earth and on the supposed difficulty of sailing up the slope of the sphere than it was upon any serious doubt of its sphericity.
The habitable world was quite a different conception. It consisted of Europe, Asia, and Africa, these three continents forming a continuous stretch of land lying on the surface of the spherical earth, the rest of its surface being presumably covered with water. There was more or less speculation about the existence of other habitable lands on the earth than those which were known, but the interest in this possibility was languid at best, and it was denied by learned churchmen on biblical grounds.
The map-makers of that period continued, like those of the earlier Middle Ages, to base their work on mere half-mythical traditions, unrelieved and uncorrected by the results of actual discoveries. Their maps are still much like picture-books, filled with biblical and literary lore, indicating but a slight attempt to incorporate exact measurements and outlines. A development more revolutionary than the mere gradual increase of knowledge was necessary to break the bonds of academic tradition. [Footnote: Santarem, Essai sur L'Histoire de la Cosmographie, I., 75, 167, 178.]
Just at the beginning of the fourteenth century, however, a new line was struck out in map-making by the construction and steady development of sailing charts, or "portolani." These humble attempts at geographical representation were intended as practical aids to navigation for Mediterranean mariners, and were based on practical observation. During the fourteenth and early fifteenth centuries they reached a wonderful degree of accuracy. The coasts, bays, islands, and promontories of the Mediterranean were plotted out in them and drawn with striking correctness. Some four hundred such sketch-maps remain to us, drawn by Italians from the fourteenth to the sixteenth centuries, besides nearly a hundred made in other countries. [Footnote: Beazley, in Hakluyt Soc., Publications, 1899, cxx.] They did not undertake to give the internal features of the countries whose coast-lines they depicted, and as their main purpose was to aid Mediterranean trade, they did not extend so far beyond its shore as the erudition of the age would have made possible.
The best of the world maps of the fifteenth century were based on these Italian portolani rather than on mediaeval maps, and at the same time added such enlarged information as became common in the Italy of the fifteenth century. [Footnote: Ibid., cxxi., etc.]