His idea, too, of the manner in which the motions are performed is strange, but may be matched elsewhere. "All the stars are created," he says, "to regulate the days and nights, the months and the years, and they move, not at all by the motion of the heaven itself, but by the action of certain divine Beings, or _lampadophores_. God made the angels for His service, and He has charged some of them with the motion of the air, others with that of the sun, or the moon, or the other stars, and others again with the collecting of clouds and preparing the rain." Similar to this were the ideas of other doctors of the [Illustration: FIG. 41.--EXPLANATION OF SUNRISE.] Church, such as S. Hilary and Theodorus, some of whom supposed that the angels carried the stars on their shoulders like the _omophores_ of the Manichees; others that they rolled them in front of them or drew them behind; while the Jesuit Riccioli, who made astronomical observations, remarks that each angel that pushes a star takes great care to observe what the others are doing, so that the relative distances between the stars may always remain what they ought to be. The Abbot Trithemus gives the exact succession of the seven angels or spirits of the planets, who take it in turns during a cycle of three hundred and fifty-four years to govern the celestial motions from the creation to the year 1522. The system thus introduced seems to have been spread abroad, and to have lingered even into the nineteenth century among the Arabs. A guide of that nationality hired at Cairo in 1830, remarked to two travellers how the earth had been made square and covered with stones, but the stones had been thrown into the four corners, now called France, Italy, England, and Russia, while the centre, forming a circle round Mount Sinai, had been given to the Arabians.