ON THE DREAM OF SCIPIO

...surface, it creates islands. Hence Cicero original: "Tullius" – Marcus Tullius Cicero, the author of the text Macrobius is commenting upon, wanting this to be understood, did not say: "every land is a certain small island," but "every land which is inhabited by us is a certain small island." This is because each of the four habitable regions Macrobius believed the world was divided into four inhabited quarters separated by oceans is made into its own small island, with the ocean twice—as we have said—surrounding them. All these things can be placed before your eyes by the diagram provided below. From it, you will see the origin of our sea The Mediterranean, which is one part of the whole, and the source of the Red and Indian Seas. You will also find where the Caspian Sea originates, although I am not unaware that there are some who deny that it has an entrance from the Ocean. Nor is there any doubt that the sea similarly flows from the Ocean into that southern temperate zone. However, this ought not to be described by our own testimony, since its location remains unknown to us.

As for what Cicero said—that our inhabitable land is narrow at the poles and wider at the sides—we will be able to notice this in the same diagram. For however much longer the tropical circle the Equator/Tropics is than the northern circle, by that much is the zone narrower at its peaks than at its sides; because its summit is contracted into a narrow space by the shortness of the outermost circle. The extension of the sides, however, is stretched out by the length of the tropic from each part. Finally, the ancients said that our whole inhabitable land, when stretched out, is similar to a chlamys: a short, oblong mantle or cloak worn by ancient Greeks. Likewise, because the whole earth (in which the Ocean also exists) holds the position of a central point relative to any celestial circle, he necessarily added regarding the Ocean: "Which, though called by such a great name, you see how small it is." For although among us it is called the "Atlantic Sea" or the "Great Sea," to those looking down from the heavens it cannot seem great; for in relation to the sky, the earth is a mere sign and a point which cannot be divided into parts. Therefore, the smallness of the earth is so diligently asserted so that the pursuit of fame might be seen as a trivial thing.

This diagram is a "Zonal Map," a common medieval way of depicting the world. It shows five climatic zones: two frozen poles, two temperate zones (ours and that of the "Antipodes" on the other side of the equator), and a scorched central zone that was believed to be impassable due to heat.