BİRİNCİ FEN · İKİNCİ BÂB · BEŞİNCİ FASIL · İkinci Madde
Article Two
Describes the outermost epicycle of Mars; along with its structure and movement.
O Noble One! Know that astronomical scholars have stated: The star Mars requires, for its orderliness, a second epicycle within the sphere of common deferment, designated as the “carrier,” which encompasses the Earth. Its center is a spherical body situated twelve degrees from the world’s center, along its diameter, enclosed by two parallel surfaces outside its direction, and surrounded by a globe. The convex surface of this sphere touches the convex surface of the first epicycle at a point called the apogee. Since the apogee is the most distant point relative to the world's center, when the star Mars arrives at that point through the movement of the “carrier,” it appears at its furthest and highest point from the Earth’s center. Similarly, the concave surface of the aforementioned second epicycle is tangent to the concave surface of the first epicycle at a point called the perigee. This is because it is the closest point relative to the world's center; and when the star Mars arrives at this point through the movement of the “carrier,” it appears quite close to and lowered towards the Earth’s center.
As is known, upon the separation of the second epicycle from the first and the emptying of the sphere mentioned above, two spheres of different sizes necessarily arise from the first epicycle; one encompasses the second epicycle, while the other is encompassed along with the second epicycle. Of these two, the thinner side of the encompassing sphere extends towards the apogee, and its thicker side towards the perigee. As for the encompassed sphere, its thin and thick sides are opposite to those of the encompassing sphere. And when the entry of these two spheres into the completion of this epicycle is fulfilled, one is called the “completer of the container” ( *mütemmim-i hâvî*), and the other the "completer of the encompassed" (*mütemmim-i mahvî*). Each epicycle has its own specific and determined movement, rotating on its own axis and poles; and since completing its rotation is a certain matter, the inclined sphere of Mars also moves westward to eastward around its own center, within its own sphere of common deferment, under Jupiter’s grand epicycle, carrying the star Mars along with it.
During its direct course, the star Mars remains in one sign for forty days, and during its retrograde motion, it stays in one sign for approximately two months, completing its cycle roughly every two years. This epicycle is distant from Earth relative to the epicycles beneath it. Because its circle is wide, its movement appears slower than that of the other planets located under Mars.