Ibn al-Raqqām’s al-Zij al-Mustawfi in MS Rabat National Library 2461

The paper contains a brief introduction on the figure of the astronomer and polymath Abū 'Abd Allāh Muḥammad Ibn al-Raqqām (fl. Tunis, Bijāya and Granada and died in Granada on 25th May 1315), and on his three zījes, based on the unfinished zīj compiled by Ibn Isḥ āq al-Tūnisī (fl. Tunis and Marrā kush ca. 1193-1222). Two of the aforementioned zījes (Shāmil and Qawīm) were carefully described by the late Professor E.S. Kennedy in 1997. Since then, a new zīj (al-Mustaufī) has been discovered and the purpose of this paper is to complete Kennedy's work by giving some information about this newly discovered text. I have also tried to establish a relative chronology of the three zījes, which seem to have been compiled between 1280 and 1290, before Ibn al-Raqqām's arrival in Granada, although the Qawīm was the object of a revision during his stay in this Andalusian city. The canons of the MusuzufiZij deal with chronology (Chapters 1-11); mean motions, with radices calculated for the beginning of the Hijra and for the longitude of Tunis (Chapters 12-13); equation of time and trepidation (Chapters 14-17); apogees and solar and lunar longitudes (Chapters 18-20); planetary longitudes and latitudes (Chapters 21-24); trigonometry and spherical astronomy (Chapters 25-55); luni-solar conjunctions and oppositions, lunar visibility, parallax and eclipses (Chapters 56- 60); topics in mathematical astrology as projection of rays, tasjīr, yt:ar, nativity and month transfers; (Chapters 61-63); trigonometry and planetary visibility (Chapters 64-65). The tables deal with 1) chronology; 2) mean motions (calculated with the same parameters as in Ibn al-Raqqām's two other zījes, the anonymous Hyderabad recension of ibn Isḥāq's Zīj and Ibn al-Bannās Minhāsj); 3) trepidation; 4) solar equation; 5) lunar equations; 6) planetary equations; 7) planetary latitudes; 8) solar declination, lunar latitude and obliquity of the ecliptic; 9) equation of time; 10) trigonometry and spherical astronomy; 11) solar and lunar velocity, parallax and eclipses; 12) auxiliary functions; 13) astrology; 14) star table giving the tropical positions of fixed stars for year 680/1280-81; 15) longitudes and latitudes of 67 cities using the water meridian (27° west of Cordova) as the base meridian. On the whole, this zīj contains further information of the influence that the Andalusian astronomer Ibn al-Zarqālluh (d. 1100) had in the development of astronomy in the Maghrib during the 13th and 14th centuries: sidereal positions which can be turned into tropical ones by using a model of trepidation, cyclical model of the obliquity of the ecliptic, motion of the solar and planetary apogees, solar model with variable eccentricity, corrections of Ptolemy's lunar model, etc., all follow the Zarqāllian tradition. On the other hand, Ibn al-Raqqām shows here, as well as in the Shāmil Zīj, the interest he felt in the solution of problems of spherical astronomy, to which he dedicates many pages of the zīj.