Part 12 (2/2)

By the middle of the third century before Christ, Eratosthenes, accepting sphericity, had by astronomical methods studied the extent of the earth's circ.u.mference, and, according to the interpretation of his results by modern scholars, he came surprisingly near to the actual size, when he exceeded the truth by perhaps a twelfth part. The calculations of Eratosthenes commended themselves to Hipparchus, Strabo, and Pliny. A century later than Eratosthenes, a new calculation, made by Posidonius of Rhodes, reduced the magnitude to a globe of about four fifths its proper size. It was palpably certain to the observant philosophers, from the beginning of their observations on the size of the earth, that the portion known to commerce and curiosity was but a small part of what might yet be known. The unknown, however, is always a terror. Going north from temperate Europe increased the cold, going south augmented the heat; and it was no bold thought for the naturalist to conclude that a north existed in which the cold was unbearable, and a south in which the heat was too great for life. Views like these stayed the impulse for exploration even down to the century of Columbus, and magnified the horrors which so long balked the exploration of the Portuguese on the African coast. There had been intervals, however, when men in the Indian Ocean had dared to pa.s.s the equator.

[Sidenote: Unknown regions.]

[Sidenote: Strabo and Marinus on the size of the earth.]

Therefore it was before the age of Columbus that, east and west along the temperate belt, men's minds groped to find new conditions beyond the range of known habitable regions. Strabo, in the first century before Christ, made this habitable zone stretch over 120 degrees, or a third of the circ.u.mference of the earth. The corresponding extension of Marinus of Tyre in the second century after Christ stretched over 225 degrees.

This geographer did not define the land's border on the ocean at the east, but it was not unusual with the cosmographers who followed him to carry the farthest limits of Asia to what is actually the meridian of the Sandwich Islands. On the west Marinus pushed the Fortunate Islands (Canaries) two degrees and a half beyond Cape Finisterre, failing to comprehend their real position, which for the westernmost, Ferro, is something like nine degrees beyond the farther limits of the main land.

[Sidenote: Ptolemy's view.]

The belt of the known world running in the direction of the equator was, in the conception of Ptolemy, the contemporary of Marinus, about seventy-nine degrees wide, sixteen of these being south of the equatorial line. This was a contraction from the previous estimate of Marinus, who had made it over eighty-seven degrees.

[Sidenote: Toscanelli's view.]

Toscanelli reduced the globe to a circ.u.mference of about 18,000 miles, losing about 6,000 miles; and the untracked ocean, lying west of Lisbon, was about one third of this distance. In other words, the known world occupied about 240 of the 360 degrees const.i.tuting the equatorial length. Few of the various computations of this time gave such scant dimensions to the unknown proportion of the line. The Laon globe, which was made ten or twelve years later than Toscanelli's time, was equally scant. Behaim, who figured out the relations of the known to the unknown circuit, during the summer before Columbus sailed on his first voyage, reduced what was known to not much more than a third of the whole. It was the fas.h.i.+on, too, with an easy reliance on their genuineness, to refer to the visions of Esdras in support of a belief in the small part--a sixth--of the surface of the globe covered by the ocean.

[Ill.u.s.tration: LAON GLOBE.

[After D'Avezac.]]

[Sidenote: Views of Columbus.]

The problem lay in Columbus's mind thus: he accepted the theory of the division of the circ.u.mference of the earth into twenty-four hours, as it had come down from Marinus of Tyre, when this ancient astronomer supposed that from the eastern verge of Asia to the western extremity of Europe there was a s.p.a.ce of fifteen hours. The discovery of the Azores had pushed the known limit a single hour farther towards the setting sun, making sixteen hours, or two thirds of the circ.u.mference of 360 degrees. There were left eight hours, or one hundred and twenty degrees, to represent the s.p.a.ce between the Azores and Asia. This calculation in reality brought the Asiatic coast forward to the meridian of California, obliterating the width of the Pacific at that lat.i.tude, and reducing by so much the size of the globe as Columbus measured it, on the a.s.sumption that Marinus was correct. This, however, he denied. If the _Historie_ reports Columbus exactly, he contended that the testimony of Marco Polo and Mandeville carried the verge of Asia so far east that the land distance was more than fifteen hours across; and by as much as this increased the distance, by so much more was the Asiatic sh.o.r.e pushed nearer the coasts of Europe. ”We can thus determine,” he says, ”that India is even neighboring to Spain and Africa.”

[Sidenote: Length of a degree.]

The calculation of course depended on what was the length of a degree, and on this point there was some difference of opinion. Toscanelli had so reduced a degree's length that China was brought forward on his planisphere till its coast line cut the meridian of the present Newfoundland.

[Sidenote: Quinsay.]

We can well imagine how this undue contraction of the size of the globe, as the belief lay in the mind of Columbus, and as he expressed it later (July 7, 1503), did much to push him forward, and was a helpful illusion in inducing others to venture upon the voyage with him. The courage required to sail out of some Iberian port due west a hundred and twenty degrees in order to strike the regions about the great Chinese city of Quinsay, or Kanfu, Hangtscheufu, and Kingszu, as it has been later called, was more easily summoned than if the actual distance of two hundred and thirty-one degrees had been recognized, or even the two hundred and four degrees necessary in reality to reach c.i.p.ango, or j.a.pan. The views of Toscanelli, as we have seen, reduced the duration of risk westward to so small a figure as fifty-two degrees. So it had not been an unusual belief, more or less prominent for many generations, that with a fair wind it required no great run westward to reach Cathay, if one dared to undertake it. If there were no insurmountable obstacles in the Sea of Darkness, it would not be difficult to reach earlier that mult.i.tude of islands which was supposed to fringe the coast of China.

[Sidenote: Asiatic islands.]

[Sidenote: c.i.p.ango.]

[Sidenote: Spanish and Portuguese explorations.]

It was a common belief, moreover, that somewhere in this void lay the great island of c.i.p.ango,--the goal of Columbus's voyage. Sometimes nearer and sometimes farther it lay from the Asiatic coast. Pinzon saw in Rome in 1491 a map which carried it well away from that coast; and if one could find somewhere in the English archives the sea-chart with which Bartholomew Columbus enforced the views of his brother, to gain the support of the English king, it is supposed that it would reveal a somewhat similar location of the coveted island. Here, then, was a s.p.a.ce, larger or smaller, as men differently believed, interjacent along this known zone between the ascertained extreme east in Asia and the accepted most distant west at Cape St. Vincent in Spain, as was thought in Strabo's time, or at the Canaries, as was comprehended in the days of Ptolemy. What there was in this unknown s.p.a.ce between Spain and Cathay was the problem which balked the philosophers quite as much as that other uncertainty, which concerned what might possibly be found in the southern hemisphere, could one dare to enter the torrid heats of the supposed equatorial ocean, or in the northern wastes, could one venture to sail beyond the Arctic Circle. These curious quests of the inquisitive and learned minds of the early centuries of the Christian era were the prototypes of the actual explorations which it was given in the fifteenth century to the Spaniards and Portuguese respectively to undertake. The commercial rivalry which had in the past kept Genoa and Venice watchful of each other's advantage had by their maritime ventures in the Atlantic pa.s.sed to these two peninsular nations, and England was not long behind them in starting in her race for maritime supremacy.

[Sidenote: Sea of Darkness.]

It was in human nature that these unknown regions should become those either of enchantment or dismay, according to personal proclivities. It is not necessary to seek far for any reason for this. An unknown stretch of waters was just the place for the resorts of the Gorgons and to find the Islands of the Blest, and to nurture other creations of the literary and spiritual instincts, seeking to give a habitation to fancies. It is equally in human nature that what the intellect has habilitated in this way the fears, desires, and superst.i.tions of men in due time turn to their own use. It was easy, under the stress of all this complexity of belief and antic.i.p.ation, for this supposable interjacent oceanic void to teem in men's imaginations with regions of almost every imaginable character; and when, in the days of the Roman republic, the Canaries were reached, there was no doubt but the ancient Islands of the Blest had been found, only in turn to pa.s.s out of cognizance, and once more to fall into the abyss of the Unknown.

[Sidenote: Story of Atlantis.]

[Sidenote: Land of the Meropes.]

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