16The reason why some planets are temperate, some hot, and others cold, appears to be this; that all fire has a flame, whose tendency is upward. Hence the sun warms, by his rays, the air above him, wherein Mars moves, and that planet is therefore heated thereby. Saturn, on the contrary, who is near the extremity of the universe, and comes in contact with the frozen regions of the heavens, is exceedingly cold. Jupiter, however, whose orbit lies between those of the two just mentioned, is tempered by the cold and heat, and has an agreeable and moderate temperature. Of the band comprising the twelve signs, of the seven planets, and their contrary motions and orbits, also of the manner and time in which they pass from one sign into another, and complete their circuits, I have set forth all that I have learnt from authors. I will now speak of the moon’s increase and wane, as taught by the antients.
16The reason why some of these stars are temperate, others hot, and others cold, appears to be this: that the flame of every kind of fire rises to higher places. Consequently, the burning rays of the sun make the ether above him white hot, in the regions of the course of Mars, and so the heat of the sun makes him hot. Saturn, on the contrary, being nearest to the outermost limit of the firmament and bordering on the quarters of the heaven which are frozen, is excessively cold. Hence, Jupiter, whose course is between the orbits of these two, appears to have a moderate and very temperate influence, intermediate between their cold and heat.
I have now described, as I have received them from my teacher, the belt of the twelve signs and the seven stars that work and move in the opposite direction, with the laws and numerical relations under which they pass from sign to sign, and how they complete their orbits. I shall next speak of the waxing and waning of the moon, according to the accounts of my predecessors.