Chorography.

Its Likeness.

A rectangular woodcut illustration divided into two compartments. The left compartment, titled "Chorography," shows a landscape with a castle or tower atop a rocky hill, several other houses, trees, and water. The right compartment, titled "Its Likeness," contains a detailed drawing of a human eye and a human ear, suggesting an anatomical analogy to the topographical view.

¶ Before anyone approaches the study of Cosmography: the science that maps the general features of the universe, including heaven and earth itself, it is necessary that they first investigate the foundation or principles of Astronomy. These consist of the knowledge of the circles of the sphere, which all of Cosmography utilizes. This will be demonstrated very briefly in the following sections.

On the motion of the spheres and the division of the heavens. Chapter second.

The World is divided into two parts: the Elemental region and the Ethereal region. The Elemental region, being subject to constant change, contains the four elements: Earth, Water, Air, and Fire. The Ethereal region, however (which philosophers call the fifth essence original: "quintā essentiam." Also known as the quintessence, believed to be the pure, incorruptible substance that makes up the heavens.), surrounds the Elemental region within its own hollow. Remaining always an unchanging substance, it encompasses ten Spheres. Of these, the larger sphere always surrounds the next smaller one in a spherical shape (in the order that follows).

First, therefore, around the sphere of fire, God, the creator of the world, placed the small sphere of the Moon. Then that of Mercury. Afterward, that of Venus. Then the Solar sphere. Then Mars, Jupiter, and Saturn. Each of these, however, has only a single star In this period, the Sun, Moon, and planets were all referred to as "stars" or "wandering stars" (planetes) to distinguish them from the "fixed stars.". These stars, while measuring out the Zodiac, always resist the motion of the First Mover: the "Primum Mobile," the outermost sphere which was believed to drive the rotation of all other spheres or tenth sphere. Otherwise, they are transparent bodies—that is, entirely translucent. Next follows the firmament, which belongs to the starry sphere, and which [moves] in two small circles...