The Sphere of the World (De Sphaera)

Who truly? has? the oblique? sphere? and who considers? it more? and the signs of it...

A circular diagram represents the oblique sphere (sphæra obliqua). A horizontal line labeled "horizon" intersects an oblique line. The quadrants are marked with the cardinal directions: "oriens" east, "meridies" south, "occidens" west, and "septentrio" north.

Those are said to have an oblique sphere whoever dwells on this side of the equinoctial line the celestial equator or beyond it: for them, one of the poles is always elevated above the horizon, while the other is always depressed. Or, because their artificial horizon intersects the equinoctial and is intersected by it at unequal and oblique angles.

Definition and order of the elementary regions? and from which they are generated? and the end of the whole world?.

What is the form of the world.

Regarding the fifth essence? quintessence of the qualities which, from its proper order?, is temporal?.

The universal machine of the world is divided into two parts: the ethereal region and the elementary region. The elementary region, being continuously subject to alteration, is divided into four. For Earth, as the center of the world, is situated in the middle of all things; around it is water, around water is air, and around air is fire, which is pure and not turbid, touching the sphere of the moon, as Aristotle says in the book of Meteorology the study of atmospheric phenomena, speaking thus: "God, glorious and sublime, arranged them in this way." These four elements are said to be those which, in turn, alter, corrupt, and regenerate from one another. Elements are simple bodies, which cannot be divided into parts of different forms. From their mixture, the diverse kinds of things are made. Any three of these surround the earth orbicularly on all sides, except insofar as the dryness of the earth resists the moisture of the water to maintain the life of living creatures. All things, except the earth, are movable; they occupy the middle of the round sphere, fleeing equally from the great motion of the extremes on all sides, just as the center of the world [does] by its own weight. Regarding the elementary region, the ethereal region is a lucid region, immune from the variation of all mutable essence, proceeding continuously in a circular motion; and this is called by philosophers the fifth essence quintessence. Of this there are nine spheres, as in the previous chapter, namely: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, the fixed stars, and the final heaven. Each of the superior spheres surrounds the inferior one. Of these, there are two motions. One is the motion of the final heaven on the two extremities of the axis, namely the arctic and antarctic poles, returning from the east through the west to the east, which the equinoctial circle divides through the middle. There is also another motion of the lower spheres, opposite to this one through an oblique path, upon their own axes, which are distant from the first by twenty-four degrees and thirty-three minutes. But the first motion drags all other spheres with it by its impetus, once within a day and a night around the earth, while they struggle against it, as [the author] says. The ninth sphere [moves] in one hundred years by one degree and twenty-eight minutes, almost dragging with it by such motion the eighth sphere and all the apogees the points in an orbit farthest from the center of the planets except that of the moon according to longitude; and thus it is called the second mobile. Contrary to this are the words of the author: "this eighth sphere [moves] in one hundred years by one degree." The zodiac divides this motion through the middle, under which each of the planets has its own sphere in which it is carried by its own motion against the motion of the final heaven, and it measures it in different spans of time: such as the ninth sphere in forty-nine thousand years. The eighth sphere, by its own motion, namely trepidation a theoretical oscillation of the celestial spheres, in seven thousand years. Saturn in thirty years, Jupiter in twelve, Mars in two, the Sun in three hundred sixty-five days and almost six hours. Venus and Mercury almost the same. The Moon, however, in twenty-seven days and eight hours.

Proper order? is temporal?.

A circular cosmological diagram. In the center is a circle representing the Earth with stylized landmasses. Surrounding it are concentric circles representing the elements and the planetary spheres. The outer rings feature decorative, wave-like patterns representing the heavens.

Distinguishes? motion from the first difference.

Others in months?.

Here? proper?.

ON the revolution of the heaven.