At the outer edges of these four seas arise massive walls closing in the whole structure and supporting the firmament or vault of the heavens, whose edges are cemented to the walls.

These walls inclose the earth and all the heavenly bodies.
The whole of this theologico-scientific structure was built most carefully and, as was then thought, most scripturally.

Starting with the expression applied in the ninth chapter of Hebrews to the tabernacle in the desert, Cosmas insists, with other interpreters of his time, that it gives the key to the whole construction of the world.

The universe is, therefore, made on the plan of the Jewish tabernacle--boxlike and oblong.

Going into details, he quotes the sublime words of Isaiah: "It is He that sitteth upon the circle of the earth;...