conjunctions of Jupiter and Saturn. A few fragments are extant as quotations by the Christian astrologer Ibn Hibinta. Liber Messahallaede revoltione liber annorum mundi, a work on revolutions, and De rebus eclipsium et de conjunctionibus planetarum in revolutionibus annorm mundi, a work on eclipses. Nativities under its Arabic title Kitab al - Mawalid, has been partially translated into English from a Latin translation of the Arabic On Reception is available in English from the Latin edition by Joachim Heller of Nuremberg in 1549. Other astronomical and astrological writings are quoted by Suter and Steinschneider. An Irish astronomical tract appears based in part on a medieval Latin version of Mashallah. Two-thirds of tract are part-paraphrase part-translation. The 12th-century scholar and astrologer Abraham ibn Ezra translated two of Mashallah's astrological treatises into Hebrew: She'elot and Ḳadrut (Steinschneider, "Hebr. Uebers." pp. 600–603). Eleven modern translations of Mashallah's astrological treatises have been translated out of Latin into English. Philosophy Mashallah postulated a ten-orb universe rather than the eight-orb model offered by Aristotle and the nine-orb model that was popular in his time. In all Mashallah's planetary model ascribes 26 orbs to the universe , which account for the relative positioning and motion of the seven planets. Of the ten orbs, the first seven contain the planets and the eighth contain the fixed stars. The ninth and tenth orbs were named by Mashallah the "Orb of Signs" and the "Great Orb", respectively. Both of these orbs are starless and move with the diurnal motion, but the tenth orb moves in the plane of the celestial equator while the ninth orb moves around poles that are inclined 24° with respect to the poles of the tenth orb. The ninth is also divided into twelve parts which are named after the zodiacal constellations that can be seen beneath them in the eighth orb. The eight and ninth orbs move around the same poles, but with different motion. The ninth orb moves with daily motion, so that the 12 signs are static with respect to the equinoxes, the eighth Orb of the Fixed Stars moves 1° in 100 years, so that the 12 zodiacal constellations are mobile with respect to the equinoxes. The eight and ninth orbs moving around the same poles also guarantees that the 12 stationary signs and the 12 mobile zodiacal constellations overlap. By describing the universe in such a manner, Mashallah was attempting to