Certain astrological and astronomical figures

These figures are in their own chapter, in which the author primarily represents this world, within which are the four elements and all things subject to birth and decay original: "generabilia et corruptibilia".

Fire is hot and dry, situated immediately below the sphere of the moon; there, however, it is so pure and clear that it is invisible.

Air is hot and moist, divided into three regions. The highest of these is joined to the sphere of fire and moves continually with the heavens from east to west.

Water is cold and moist, naturally situated between the air and the earth. However, one part of the earth, being less heavy than the rest, stands above the water and is naturally uncovered by the waves so that it may be habitable. Some assert that the greatest depth of the ocean is 14 miles, as discovered by sailors; they say this depth is less than half the distance from the center of the world to the center of the earth.

Earth is round, or rather has a shape that is nearly a sphere. Its circumference contains 360 portions degrees corresponding to the same number of degrees in the heavens. To each degree on earth, there correspond 700 stadia an ancient unit of distance, of which eight make a mile, and two miles make a league. From this, some conclude that the entire circumference of the earth contains 15,750 leagues.