Essay Review: Notes on Yemeni Astronomy in the Rasulid Period

The Manuscript of al-Malik al-Afdalal-'Abbâs b. 'Alî b. Dâ'ûd b. Yûsuf b.'Umar b. 'Alî ibn Rasûl; A Medieval Anthology from theYemen, edited with an introduction by Daniel Martin Varisco andG. Rex Smith, Aris & Phillips Ltd, Warminster, Wiltshire, U.K.,for the E.J.W. Gibb Memorial Trust, 1998. 27 + 542 pp.

Reviewed by David A. King
Institute for the History of Science
Johann Wolfgang Goethe University
60054 Frankfurt am Main, Germany

Yemen Update 44 (2002)

[Editor's Note: Due to the limitations of html (when this was first published), it has not been possible to indicate proper transliteration for all the Arabic letters. ]

The Rasulid Sultan al-Afdal (d. 1377) was acultured man, interested in many aspects of the world around him andits history. He is known to have compiled a dozen or so works, mainlyon history but also on agriculture, medicine, astronomy and magic,only half of which are known to have survived. By way of compensationfor historians of the Yemen, there has been preserved for us ananthology by an unidentified copyist (possibly one of his recentancestors?) dealing with all manner of subjects, which was once inhis possession, for it includes notes in his own hand written theyear before he died. No amount of praise is adequate for the copyistand for al-Afdal; for its present owner, who had the foresight tomake it available for a facsimile edition; and the two editors, whorecognized its potential value for future research. Inspired andencouraged by the late Professor Robert Bertram Serjeant, to whosememory the volume is dedicated, the last two mentioned valiantlyacquired photographs of the whole manuscript with over 540 pages, andordered them in an entirely sensible fashion, now paginated. Theyalso included a brief introduction to the Rasulids, on whom Rex Smithis the expert outside the Yemeni world, and to al-Afdal, as well asproviding a most useful table of contents for the manuscript in 15pages. Their goal was achieved in making this remarkable historicaldocument available to a wider public.

It is almost five years since that facsimileof al-Afdal's Anthology was published. How dare a reviewer delay solong to write a review of a pair of colleagues and friends? Thereason is simple: what Dan Varisco hoped I would produce was adetailed overview of the extensive sections of the anthology dealingwith astronomy, astronomical instruments and astrology. This, alas,is still not forthcoming. Rather, what I shall do is simply to repeatthe gist of what I wrote some 20 years ago on the astronomicalcontent of this manuscript, adding a few bibliographical referencesto point to some more recent research on Yemeni astronomy in general,that is, not just on this manuscript. It would be inappropriate notto mention various studies of other parts of al-Afdal's Anthologythat have appeared since the publication of the facsimile: theseinclude The King's Dictionary. The Rasulid Hexaglot: FourteenthCentury Vocabularies in Arabic, Persian, Turkic, Greek, Armenian andMongol (Leiden: Brill, 2000), edited by Peter B. Golden; and D.M. Varisco's, "Agriculture in Rasulid Zabid." (Journal of SemiticStudies, Supplement 14. Studies on Arabia in Honour of ProfessorG. Rex Smith, edited by J. F. Healey and V. Porter, 323-351,Oxford:Oxford University Press, 2002.)

My first encounter with al-Afdal'smanuscript was in 1970-71 at the American University of Beirut, whereI had the pleasure of studying Ancient South Arabian with ProfessorMahmoud Ghul. I was conducting research for my doctoral dissertationon the works of the Fatimid astronomer Ibn Yûnus and happenedto mention to Prof. Ghul that I had found that some of the Egyptianscholar's works had been known in the Yemen, whereupon he allowed meto make a copy of his microfilm of al-Afdal's Anthology. It was thusas a result of his kindness that I was able to include an overview ofthe astronomical contents in my book on Yemeni astronomy that waspublished some 10 years later (Mathematical Astronomy in theMedieval Yemen, 1983, hereafter abbreviated MAY). I also analysedsome of the tables in that manuscript that related to timekeeping,but only now, 30 years later, are those descriptions finally beingpublished (Studies in Astronomical Timekeeping in MedievalIslam, in press, hereafter SATMI).

Overviews of the two traditions of Islamicastronomy, the first as practiced by the astronomers of medievalIslam and the second, non-mathematical folk astronomy, as practicedby the legal scholars, are to be found in King, "Islamic Astronomy", and Varisco, "Islamic Folk Astronomy" in The History ofNon-Western Astronomy: Astronomy Across Cultures, edited byHelaine Selin (Dordrecht: Kluwer Academic Publishers, 2000).Recently, not least to provide the article "ZÎDJ" in the newedition of the Encyclopaedia of Islam (EI2), I have,together with Julio Samsó, prepared an overview of Islamictables and astronomical handbooks, including the most importantYemeni examples. This research is being continued by Benno van Dalen; for further information see his "Website".

The following is a brief account of theastronomical contents of the Anthology [expanded from MAY,p. 37, ad al-Afdal (no. 18)]:

  1. There are numerous passages and tables taken from the Kitâb al-Mabâdi' wa-'l-ghâyât fî 'ilm al-mîqât, "An A to Z of Astronomical Timekeeping", by the late-13th-century Cairo astronomer Abû 'Alî al-Marrâkushî (see now my article "al-Marrâkushî" in EI2). This important work is now available in facsimile edition (Frankfurt), in addition to the well-known studies of the Sédillots père et fils from the 19th century (repr. Frankfurt). It still awaits detailed study, but it has been exploited in the study of a later Egyptian work by Najm al-Dîn al-Misrî in Charette, Mathematical Instrumentation.
  2. There are various tables taken from the Mustalah Zîj, which was the most-widely used zîj in Mamluk Cairo, but which alas does not survive in its original form (King & Samsó, "Islamic Astronomical Tables", p. 50). On one of these see further below.
  3. There are some tables taken from the extensive corpus of tables for timekeeping by the sun and the stars entitled Mir'ât al-zamân and compiled ca. 1300 for the latitude of Ta'izz by Abu 'l-'Uqûl (MAY, no. 9). The tables in this corpus are now analysed in King, SATMI, I-2.1.2, etc., and II-12.1. Furthermore, more information on the elusive author has been discovered (see Varisco, Yemeni Almanac, p. 13): he is Muhammad ibn Ahmad al-Tabarî, the first teacher appointed by the Sultan al-Mu'ayyad to his new madrasa in Ta'izz.
  4. Some geographical tables attributed to the late-12th-century Syrian astronomer Ibn al-Dahhân are all that survives from that author. See now King, SATMI, II-9.1.
  5. Some tables are attributed to Ibn al-Mushrif (MAY, no. 12), who may be identical with a 14th-century Egyptian astronomer with that name. See further King, SATMI, I-9.8, etc., and II-6.15.
  6. Some planetary tables are stated to be from the Kitâb al-Shams al-Harîrî, presumably a zîj by one Shams al-Dîn al-Harîrî, otherwise unknown and not yet identified.
  7. Other tables are taken from the Yemeni Muzaffarî Zîj of al-Fârisî (see King, MAY, no. 6.3, and King & Samsó, "Islamic Astronomical Tables", p. 52).
  8. Other tables are taken from the Iranian Îlkhânî Zîj of Nasir al-Dîn al-Tûsî (see King & Samsó, "Islamic Astronomical Tables", p. 46).
  9. An almanac displaying various spherical astronomical functions for each day of the solar year is introduced in the name of al-Afdal himself but the same almanac occurs in the Berlin manuscript of the Mir'ât al-zamân of Abu 'l-'Uqûl (see above). Information is available in Varisco, Yemeni Almanac.
  10. A short treatise of one page attributed to al-Afdal deals with a celestial sphere that he made in 776 H [= 1374]. Alas, all other traces of this instrument have disappeared and it is not mentioned in Savage-Smith, Islamic Globes.
  11. A table displaying the solar longitude for each day of the year is stated to have been compiled by al-Afdal in 777 H [= 1375/76].
  12. A short treatise on the astrolabe is attributed to the Rasulid Sultan al-Mu'ayyad (MAY, no. 10); this is not known from other sources.

I concluded my first description 20 yearsago with words that are still valid:

"A more detailed description of the contents of this manuscript would obviously be worthwhile, but the need for investigations of the works of al-Marrâkushî, the Egyptian Mustalah Zîj, and the Yemeni Muzaffarî and Mukhtâr Zîjes, is more urgent."

In my 1983 book, I identified two Yemeniephemerides (taqwîm, pl. taqâwîm) forthe years 727 H [= 1326/27] and 808 H [= 1405/06],unique of their genre (MAY, nos. 11 and 22). We have onlyfragments of similar works preserved in a citation byal-Bîrûnî and leaves from the CairoGeniza.

  • A detailed investigation of these ephemerides is in preparation as a doctoral thesis by Michael Hofelich of Frankfurt: see already his article "TAKWÎM" in EI2.

I also pointed to the importance of certainearly Yemeni works on folk astronomy for our understanding of aspectsof Islamic ritual. We note the following more recent and otherimminent publications

  • An analysis of the Yemeni materials on timekeeping by arithmetical and other simple shadow-schemes: see King, "Shadow-Schemes."
  • The agricultural almanac of al-Afdal has been published with a detailed commentary: see Varisco, Yemeni Almanac.
  • A study of a text by the mid-13th-century scholar Muhammad ibn Abî Bakr al-Fârisî of Aden (MAY, no. 6.1) on the astronomical orientation of the Ka'ba: see now King with Gerald Hawkins, repr. in King, Studies, C-XII).
  • The materials on sacred geography &endash; the notion of the world divided into sectors about the Ka'ba at the centre; in Yemeni sources, in particular a reconstruction of three schemes proposed by the Yemenifaqîh, Muhammad ibn Surâqa, ca. 1000 (see MAY, p. 21); have been analysed together with similar materials from other regions. See King, Sacred Geography, as yet unpublished, with a summary in the article "MAKKA. iv. As centre of the world" in EI2, repr. in King, Studies, C-X.
  • A detailed study of the materials relating to the prayer-times and the qibla in the treatises on folk astronomy of Ibn Rahîq (Mecca, 11th (?) century), al-Asbahî (Janad, 13th century) and al-Fârisî (Aden, 13th century)(MAY, nos. 2.1, 5.1 and 6.1) has been virtually completed. See Schmidl, Thesis, and also eadem, "Qibla und Winde".

Some non-Yemeni materials on mathematicalastronomy preserved in Yemeni sources have also beenstudied:

  • A list of 13 observations made in Qûs and Alexandria reported in the zîj of the 13th-century Yemeni astronomer Muhammad ibn Abî Bakr al-Kawâshî (MAY, no. 7): see now King with Owen Gingerich, repr. in King, Studies, A-VII.
  • The mathematical structure and the mode of compilation of a highly-sophisticated lunar table has been explained with the help of another table preserved in the Anthology and a remark by al-Afdal on its provenance (see King, Studies, A-V).

Considerable research has been conducted inrecent years on astronomical instrumentation (see King, "InstrumentWebsite"). In particular, progress has been made on the history ofastronomical instrumentation in the Yemen. One astrolabe made by theSultan al-Ashraf (MAY, no. 8) in 690 H [= 1291] hasbeen preserved for us and is now in the Metropolitan Museum of Art inNew York. Also, his treatise on the construction of astrolabes,sundials, and the magnetic compass has been studied furthe

  • A detailed description of al-Ashraf's astrolabe, also drawing on his treatise on instrumentation, has been published: see King, Studies, B-II.
  • Another Yemeni astrolabe, also of Rasulid provenance but undated and unsigned, has been identified in a collection at Harvard University. A description has been made but is not yet published.
  • Al-Ashraf's treatise also contains the earliest description of a magnetic compass bowl in which the needle floats on water or some liquid. His text, together with a contemporaneous text from Cairo on a dry compass, is now published: see Schmidl, "Compass".

In conclusion, much has been done on thehistory of Yemeni astronomy in the past 30 years, but not enough.There is still much more to be done, but the field is vast and thenumber of workers few indeed. al-Afdal and his modern editors havecontributed substantially to our endeavours.

Bibliography and bibliographicalabbreviations

al-Afdal, Anthology

= the work under "review".

Charette, François, Mathematical Instrumentation

Mathematical Instrumentation in 14th-Century Egypt and Syria, (doctoral dissertation, Frankfurt, 2002) in press with E. J. Brill of Leiden.


The Encyclopaedia of Islam, new edn., Leiden: E. J. Brill, 1960 to present.

Hofelich, Michael, Thesis

Ephemerides from Medieval Yemen, doctoral dissertation, Frankfurt University, in preparation.

King, David A.

"Instrument Website" =

"Islamic Astronomy" = ""Islamic Astronomy", in H. Selin, ed., Astrononomy across Cultures (Dordrecht: Kluwer, 2000)

MAY Mathematical Astronomy in the Medieval Yemen, Malibu, Ca.: Undena, 1983.

Sacred Geography = The Sacred Geography of Islam, to be submitted to E. J. Brill. [For a summary, see the article "MAKKA. iv. As centre of the world" in EI2.]

"Shadow-Schemes" = "A Survey of Medieval Islamic Shadow Schemes for Simple Timereckoning", Oriens 32 (1990), pp. 191-249. [A new version is in SATMI, III.]

Studies, A-C = Islamic Mathematical Astronomy, London: Variorum, 1986, 2nd rev. edn., Aldershot: Variorum, 1993 (A); Islamic Astronomical Instruments, London: Variorum, 1987, repr. Aldershot: Variorum, 1995 (B); and Astronomy in the Service of Islam, Aldershot: Variorum, 1993 (C).

SATMIStudies in Astronomical Timekeeping in Medieval Islam, 12 pts., Leiden: E.J. Brill, in press. [For a summary see the article "MIKÂT. ii. Astronomical Aspects" in EI2.]

King & Julio Samsó, "Islamic Astronomical Tables"

= "Astronomical Handbooks and Tables from the Islamic World (750-1900): An Interim Report", Suhayl; Journal for the History of the Exact and Natural Sciences in Islamic Civilisation (Barcelona) 2 (2001), pp. 9-105. [A summary is in the article "ZÎDJ" in EI2.]

Savage-Smith, Emilie, Islamic Globes

= Islamicate Celestial Globes -- Their History, Construction, and Use, Washington, D.C.: Smithsonian Institution Press, 1985.

Schmidl, Petra,

"Compass" = "Two Early Arabic Sources on the Magnetic Compass", Journal of Arabic and Islamic Studies 1 (1996-97), pp. 81-132. [Electronic journal accessible on the Internet via]

"Qibla und Winde" = "Zur Bestimmung der Qibla mittels der Winde", in Peter Eisenhardt et al., eds., Der Weg der Wahrheit; Aufsätze zur Einheit der Wissenúschaftsúgeschichte; Festgabe zum 60. Geburtstag von Walter G. Saltzer, Hildesheim: Olms, 1999, pp. 135-146.

Thesis = Volksastronomische Abhandlungen aus dem mittelalterlichen arabisch-islamischen Kulturraum, doctoral dissertation, Frankfurt University, 2003.

Selin, H. ed., Astrononomy across Cultures

The History of Non-Western Astronomy: Astronomy Across Cultures, Helaine Selin, ed., Dordrecht, etc.: Kluwer, 2000.

van Dalen, Benno, "Website"

Varisco, Daniel M.

"Islamic Folk Astronomy" = "Islamic Folk Astronomy", in H. Selin, ed., Astronomy across Cultures, pp. 615-650.

Studies = Medieval Folk Astronomy and Agriculture in Arabia and the Yemen, (Variorum Collected Studies Series: CS585), Aldershot & Brookfield, Vt.: Ashgate-Variorum, 1997.

Varisco, Yemeni Almanac

Medieval Agriculture and Islamic Science: The Almanac of a Yemeni Sultan, Seattle, Wa.: University of Washingúton Press, 1993.

Varisco & Smith, eds., al-Afdal's Anthology

= the work under review.

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