Histories & Culture
History of the Astronomical Handbook (zij) in 14th century Fez

1. Introduction


A certain Abul'l-Hasan Ali b. Abi Ali al-Qusuntini 1 compiled in fourteenth century Fez a sort of miniature zij, or astronomical handbook, comprising tables and explanatory text, which he dedicated to the Marinid Sultan Ibrahim al-Musta’in. This zij is distinguished by the fact that the explanatory text is in verse 2. Many mathematical and astronomical poems, some of considerable sophistication, were composed during the Islamic Middle Ages; most of these were Maghribi compilations and most are as yet unstudied in modern times.3 The zij is the only known document extant in Arabic in which the planetary theory is essentially Indian rather than Ptolemaic. This Indian planetary theory, popular amongst certain early Muslim astronomers4, and not without influence in Andalusia and the Maghrib throughout the medieval period, is known to be based on pre-Ptolemaic Greek astronomical models. The zij of al-Khwarizmi was also based on Indian planetary theory, but it has survived only in the Latin translation of an ex¬tensive reworking of the original by al-Majriti. The first part of the same manuscript contains a copy of the zij of the thirteenth-century Moroccan astronomer Ibn al-Banna', upon which, al-Qusuntini leans heavily. The introduction is written in rajaz meter.

2. Brief Survey of Astronomy in the Maghrib


The following account is the first attempt in the modern literature to out¬line the history of astronomy in the Maghrib 5. The evidence indicates that such cities as Marrakesh, Tunis, Taza, and Tlemcen, were the scene of an active tradition of astronomy for several centuries. 

From the first five centuries of Islam only one author is known to us from the Maghrib, namely, the astrologer Ibn Abi'l-Rijal, who worked at the Zirid court in Tunis ca. 1045. Thereafter we have reports of isolated measure¬ments of the obliquity of the ecliptic conducted by an unnamed astronomer in Meknes, by Ibn Hilal in Sebta, by al-Mirrikh in Marrakesh, and by Ibn al- Turjuman in an unspecified location, all dating apparently from the twelfth and thirteenth centuries.


The activities of al-Zarqallu in Cordova and Toledo in the eleventh century appear to have had more influence in Europe than they had in later Islamic astronomy. The Andalusian astronomer Ibn al-Kammad seems to have based his zijes on the work of al-Zarqallu, and at least one of his zijes was in use in the Maghrib in the thirteenth century. A Maghribi astronomer, who is known to have relied on a zij of Ibn al-Kammad and also on the observations of a Sicilian Jew, was Ibn Ishaq, a Tunisian who worked in Morrocco in the early thirteenth century. He compiled a zij which Ibn Khaldun tells us was widely used in the Maghrib in the fourteenth century. Ibn Ishaq quotes several earlier scholars whose works are no longer available in their original form: for example, in his chapter on lunar crescent visibility he cites the opinions of the earlier Andalusian astronomers Ibn Mu’adh and Abu’l-Hajjaj al-Sabti, the latter a student of Maimonides, as well as others whose names are new to the modern literature.

In passing we should mention that the late thirteenth-century scholar Abu ‘Ali al-Marrakushi, author of an enormous compendium on spherical astronomy and instruments entitled Jami’ al-mabadi' wa'l-ghayat, hailed from the Maghrib but wrote his treatise in Cairo. Indeed, al-Marrakushi's work, which was highly influential in Egypt, Syria, and Turkey, appears to have been unknown in the Maghrib. 

The Moroccan scholar Ibn al-Banna' commpiled a zij in Marrakesh about the year 1300. This survives in several copies. The astronomer Ibn al-Raqqam compiled in Tunis in the early fourteenth century two zijes, both of which are extant in unique manu¬scripts and have yet to be studied. One of Ibn al-Raqqam's zijes is said by the author to be based on another by Abu'l-Hasan ibn ‘Abd al-Haqq called Ibn al-Ha'm, a person otherwise unknown to us. The zij of al-Qusuntini was not the only baby zij compiled in the Maghrib. Ibn al-Qunfudh in the late fourteenth century compiled a small zij for Tlemcen based on the zij of Ibn al.Banna'. No other zijes specifically for Fez or Tlemcen are known to us.

A recension for Algiers of the zij of Ibn al-Shatir, the celebrated astronomer of fourteenth-century Damascus, is known from a single manuscript. Consid¬erably more influential was the zij of Ulugh Beg, compiled in fifteenth-century Samarqand: Tunisian recensions were prepared by Abu ‘Abd Allah Muhammad al-Tunisi known as Sanjaq Dar and by Husayn Qus’a, and both survive in several copies. The late fifteenth century Jewish astronomer Zacuto compiled his perpetual almanac in Salamanca. These tables in a modified form were apparently used in the Maghrib (as well as in Ottoman Turkey), and the introduction to them was translated into Arabic by Andalusian astronomers.

In Marrakesh in the early thirteenth century and in Taza in the early fourteenth century, astrolabes of excellent construction were being produced. In the late thirteenth and early fourteenth centuries there were constructed in Fez two astronomical clocks, of a kind known otherwise only from mid-¬fourteenth century Damascus. The first clock was set up in al- Qarawiyyin Mosque and the second in the Bu’inaniyya madrasa: both were water¬clocks fitted with an astrolabic rete. The first clock, in its later form, is still in situ although the gear mechanisms have gone, and most of the second clock has disappeared. Several later Maghribi astrolabes and quad¬rants survive in museums around the world, attesting to a continuing interest in instrumentation in the Maghrib until the nineteenth century.

In the fourteenth century extensive sets of tables for time-keeping by the sun and stars and for regulating the astronomically-defined times of prayer were compiled in Tunis after the model of the tables currently in use in Damas¬cus. Another smaller set of tables for regulating the times of prayer was prepared for different localities in Morocco. A sundial from fourteenth century Tunis reflects the interest of the Maghribis in times of day with special religious significance that had no counterpart in contemporary practice in Mamluk Egypt and Syria. The times are not displayed on a later Tunisian sundial in the Mosque of Sidi 'Uqba in Qayrawan, but yet other times are tabulated in some Ottoman prayer-tables for Algiers. The position of the mu'addil appears to have been the Maghribi equivalent to of the muwaqqit of the Mamluk world, that is, the astronomers associated with mosques and madras as who were responsible for regulating the astronomically-defined times of the five, or occasionally in the Maghrib six, daily prayers.

As elsewhere in the medieval Islamic world there existed in the Maghrib alongside this scientific activity in astronomy a tradition of primitive folk astronomy. The pronouncements of one Abu Miqra’, who lived in the thir¬teenth century, were accorded far more respect than was warranted by their scientific content.

About the year 1300 the astronomer Ibn al-Banna' compiled an almanac of the same kind as the earlier and better-known Calendar of Cordova. At the end of the fourteenth century a certain al-Jadari wrote a poem on timekeep¬ing which was much commented upon in later centuries. This kind of ma¬terial is worth studying for its own sake but also has special rewards for the historian of science: in an anonymous commentary on al-Jadari's poem com¬piled in Tlemcen in the sixteenth century there are accounts of considerable historical interest concerning earlier Maghribi activity in measurements of the obliquity of the ecliptic, trepidation, and twilight determina¬tions. 

Astronomical activity in the Maghrib continued until the colonial period, but by then the great zijes of Ibn Ishaq and Ibn al-Banna' and most of the underlying theory had been long forgotten. Rather, a plethora of poems on folk astronomy and on the use of the almucantar and sine quadrants for timekeeping were the favorite reading of those who passed as astronomers. As we have shown, the earlier Maghribi tradition was relatively rich and is of considerable importance to the history of Islamic astronomy. Furthermore as we have noted, most of the relevant sources have yet to be studied properly. The historical and biographical sources must also be exploited before we can gain a clearer picture of astronomy in the medieval Maghrib.

1. The epithet al-Qusuntni indicates that he or his family was originally from Qusuntiniya (= Constantine) on the Algerian littoral. He is not known to have compiled any other works, but we have not consult¬ed any medieval Maghribi biographical works. He is referred to as al-faqih, which indicates his interest in law, and as al-mu’addil, which indicates that he was a professional time-keeper associated with a mosque and responsible for the regulation of the times of prayer.


2. The only other zij known to us which may have been written in verse is called al-Zij al-manzum, and its arrangement in verse is implied by the title, al-Sirr al-maktum fi-l-‘amal bi'l-zij al-manzum of a work attributed to the fourteenth-century Syrian scholar Abu'l-Fidii', and ex¬tant in a unique manuscript in Oxford..


3. Some examples of the most popular scientific works in verse are the astrological poem of Ibn Abi’ 'l-Rijal; the poem on algebra by Ibn al-Yas¬min; the poem on timekeeping by al-Jadari; and the poem on all aspects of science by ‘Abd al-Rahman al-Fasi entitled al- Uqnum. Each of these authors worked in the Maghrib.


4. On the influence of Indian astronomy in early Islamic astronomy Prof. Pingree informs us that there are several Sanskrit manuscripts in existence of a work entitled Yantra Jarkali, suggesting that al-Zarqallu's works had some modest influence in later Indian astronomy.


5. The standard bio-bibliographical sources in which Maghribi astronomers and their works are listed are the following: Suter 1; Renaud 1; Brockelmann, II, pp. 331-332 and 615-616, and SII, pp. 364-365 and 707-709; Azzawi, pp. 209.221; and Cairo Survey, Section F. See also Renaud 2 on astron¬omy in Morocco and King 1, pp. 192-193 on astronomy in Tunis. On Maghribi astrolabists and their works see Gunther, I, pp. 248-301; Renaud 4; Mayer, passim; and Brieux & Maddison. Maghribi con¬tributions to mathematics are surveyed in Djebbar.



Courtesy: Professor E. S. Kennedy. Excerpted from Indian Astronomy in Fourteenth Century Fez: The Versified Zij of al-Qusuntini, E.S. Kennedy & David A. King. Volume 6, Numbers 1& 2, 1982. University of Aleppo Press, Syria.