"Since, then, the shadow of the earth is round, it is a proof that the earth is round also."

This of course is one of the proofs that would be employed in the present day for the same purpose.

The most remarkable of all the fantastical systems, however, the chef d'œuvre of the cosmography of that age, was the famous system of the square earth, with solid walls for supporting the heavens. Its author was Cosmas, surnamed Indicopleustes after his voyage to India and Ethiopia. He was at first a merchant, and afterwards a monk. He died in 550. His manuscript was entitled "Christian Topography," and was written in 535. It was with the object of refuting the opinions of those who gave a spherical form to the earth that Cosmas composed his work after the systems of the Church Fathers, and in opposition to the cosmography of the Gentiles. He reduced to a systematic form the opinions of the Fathers, and undertook to explain all the phenomena of the heavens in accordance with the Scriptures. In his first book he refutes the opinion of the sphericity of the earth, which he regarded as a heresy. In the second he expounds his own system, and the fifth to the ninth he devotes to the courses of the stars. This mongrel composition is a singular mixture of the doctrines of the Indians, Chaldeans, Greeks, and Christian Fathers.

With respect to his opponents he says, "There are on all sides vigorous attacks against the Church," and accuses them of misunderstanding Scripture, being misled by the eclipses of the sun and moon. He makes great fun of the idea of rain falling upwards, and yet accuses his opponents of making the earth at the same time the centre and the base of the universe. The zeal with which these pretended refutations are used proves, no doubt, that in the sixth century there were some men, more sensible and better instructed than others, who preserved the deposit of progress accomplished by the Grecian genius in the Alexandrian school, and defended the labours of Hipparchus and Ptolemy; while it is manifest that the greater number of their contemporaries kept the old Indian and Homeric traditions, which were easier to understand, and more accessible to the false witness of the senses, and not improved by combination with texts of Scripture misinterpreted. In fact, cosmographical science in the general opinion retrograded instead of advancing.

According to Cosmas and his map of the world, the habitable earth is a plane surface. But instead of being supposed, as in the time of Thales, to be a disc, he represented it in the form of a parallelogram, whose long sides are twice the shorter ones, so that man is on the earth like a bird in a cage. This parallelogram is surrounded by the ocean, which breaks in in four great gulfs, namely, the Mediterranean and Caspian seas, and the Persian and Arabian gulfs.

Beyond the ocean in every direction there exists another continent which cannot be reached by man, but of which one part was once inhabited by him before the Deluge. To the east, just as in other maps of the world, and in later systems, he placed the Terrestrial Paradise, and the four rivers that watered Eden, which come by subterranean channels to water the post-diluvian earth.

After the Fall, Adam was driven from Paradise; but he and his descendants remained on its coasts until the Deluge carried the ark of Noah to our present earth.

On the four outsides of the earth rise four perpendicular walls, which surround it, and join together at the top in a vault, the heavens forming the cupola of this singular edifice.

The world, according to Cosmas, was therefore a large oblong box, and it was divided into two parts; the first, the abode of men, reaches from the earth to the firmament, above which the stars accomplish their revolutions; there dwell the angels, who cannot go any higher. The second reaches upwards from the firmament to the upper vault, which crowns and terminates the world. On this firmament rest the waters of the heavens.

Cosmas justifies this system by declaring that, according to the doctrine of the Fathers and the Commentators on the Bible, the earth has the form of the Tabernacle that Moses erected in the desert; which was like an oblong box, twice as long as broad. But we may find other similarities,—for this land beyond the ocean recalls the Atlantic of the ancients, and the Mahomedans, and Orientals in general, say that the earth is surrounded by a high mountain, which is a similar idea to the walls of Cosmas.