Note 107 — Chapter III · 1474-1492.

Columbus, in his investigations, no doubt, became informed concerning the arguments advanced by the Greek astronomer, Anaximander, in the sixth century before the Christian era, respecting the globular form of the earth. He evidently read what Aristotle wrote in the fifth century of the Christian era: “As to the figure of the earth, it must necessarily be spherical.... And, moreover, from the visible phenomena, for if it were not so, the eclipses of the moon would not have such sections as they have. For in the configurations in the course of a month, the deficient part takes all different shapes; it is straight, and concave, and convex; but in eclipses it always has the line of division convex; wherefore, since the moon is eclipsed in consequence of the interposition of the earth, the periphery of the earth must be the cause of this by having a spherical form. And again, from the appearance of the stars, it is clear not only that the earth is round, but that its size is not very great; for when we go a little distance to the south or to the north, the circle of the horizon becomes palpably different, so that the stars overheard undergo a great change, and are not the same to those that travel to the north and to the south. For some stars are seen in Egypt and at Cyprus, but are not seen in the countries north of them; and the stars that in the north are visible while they make a complete circuit there [in Egypt and at Cyprus], undergo a setting. So that from this it is manifest, not only that the form of the earth is round, but also that it is not a very large sphere; for otherwise the difference would not be so obvious to persons making so small a change of place. Wherefore we may judge that those persons who connect the region in the neighborhood of the Pillars of Hercules with that toward India, and who assert that in this way the sea is one, do not assert things very improbable. They confirm this conjecture, moreover, by elephants, which are said to be of the same species toward each extreme of the earth, as if this circumstance was a consequence of the conjunction of the extreme parts. The mathematicians, who try to calculate the measure of the circumference, make it amount to 400,000 stadia; whence we infer that the earth is not only spherical, but that it is not large compared with the magnitude of the other stars,”—De Cœlo. lib. ii. cap. xiv.