In Synchrony with the Heavens: Studies in Astronomical Timekeeping and Instrumentation in Medieval Islamic Civilization, Volume One: The Call of the Muezzin (Studies I-IX) by David A. King (Brill, Leiden, 2004; ISBN xx, hardcover) B&W illus.,  lvii+lviiii pp.


Reviewed by Imad-ad-Dean Ahmad, Minaret of Freedom Institute


[published in Archeoastronomy: The Journal of Astronomy in Culture XIX (2005), p. 103.]


Brill is one of the most important Western publishers of Islamic material and David King is one of the most important scholars of the history of Islamic astronomy. So this book, volume LV in Brill’s series Islamic Philosophy, Theology and Science: Texts and Studies is a serious addition to a major branch of ethnoastronomy. At the same time, its large size, heavy stock, glossy pages and numerous black and white illustrations make this weighty volume a candidate for your coffee table. There is also a companion volume with six more studies added to the twelve that make up the nine parts of volume I.


I do not believe I have ever seen a first edition with two prefaces before, but I can well-understand King’s motive for his second preface entitled “Some Brief Remarks on the Islamic Scientific Heritage in the Context of the Transmission of Scientific Ideas.” Like King, I have been appalled at the ignorance, not only among the general public, but even among some historians of science, of the role of Islamic science in the development of “global science.” King notes that the works that Europeans rescued from Muslim Spain had already been surpassed elsewhere in the Muslim world.


In one sense this is an annotated catalog of available source material on the subject, but it is more, in that King has assembled a compelling case for understanding timekeeping as a branch of astronomical science developed in the classical Islamic civilization. Many sections make compelling reading on their own account. For example, there is a charming section in which King takes us through the errors in a 19th century French painting of men at prayer on a Cairo roof (p. 861).


King has reviewed an enormous amount of material with evident care, beginning with al-Fazari’s work in the 8th century. He even includes an entire section (VIIb, pp. 773-823) devoted to a lengthy discussion of ventilator orientation because of its connection to qibla (direction of prayer) orientation and the role of astronomy in city planning.


The first half of the book, Parts I and II, are surveys on tables for timekeeping by the sun and stars, and tables for regulating the times of prayer and contain many equations. The second half of the book is lighter on the mathematics. Part III is on arithmetical shadow-schemes for time reckoning, Part IV on the times of Muslim prayer, Part V on the role of the muezzin (who calls people to prayer) and the muwaqqit (timekeeper) in medieval Islamic society, Part VI on universal solutions in Islamic astronomy and to problems of spherical astronomy from Mamluk Syria and Egypt, Part VII architecture, city planning and world maps centered on Mecca, Part VIII on practical astronomy in mosques and monestaries. The last part (IX) is about some tables King considers “virtually without precedent or successors in the history of astronomy” which have “nothing to do with ‘astronomy in the service of Islam,’ but are astrological instead. The inclusion of this part seems mainly motivated by musings over current events, indicated by its title “When the Night Sky over Kandahar Was Lit Only by Stars.”


One expects typographical errors to creep into a volume of the scope, as the errata page attests. There are many other typos not caught on the errata page and King quotes the classical Muslim writers plea “If you find a mistake, (please) fix it.”


Most medieval Islamic literature is still not properly cataloged. For example, King notes, “Only recently has the history of astronomy in the Maghrib been surveyed” (p. 427) and that “only in the middle of [the twentieth] century has it become clear to what extent” medieval Muslims “had a passion for tables and instruments.” The work in this book was done over many years of time and is presented as a set of twelve overlapping studies organized into nine parts. As much as I admire and enjoyed this book, I wish that more effort could have been devoted to integrating the material. Not only is there considerable redundancy between the various parts, but there are some seeming inconsistencies. Although King has an outstanding summary of the issues surrounding the time of the `asr prayer in Part IV, including the fact that the Hanafi school places the time of ‘asr prayer as beginning when the shadow of a gnomon has reached two gnomon lengths in excess of its noon length, and the Shafi school places this as ending time of that prayer, in several other places (e.g., p. 558) he seems to attribute the Shafi view to the Hanafis. 


Medieval Muslims approached the problems of calculation of prayer times and directions and the calendar by three different means: tradition (blind imitation of the early Muslims, e.g., facing South when one prays because that is the direction of Mecca from Medina where the first Muslim community prayed), folk astronomy (ethnoastronomy in its narrow meaning) and mathematical astronomy (which in Medieval Islam was innovative and highly developed). King brings nuance and sophistication to the important issue of the relationship between folk astronomy and mathematical astronomy. One amusing example is the case of the Karramiya who sought to resolve a dispute between two schools regarding the start of the `asr (mid-afternoon) prayer by using the average of the two. This only created a new dispute over whether one should average the seasonal hours or the associated shadow lengths.


The complex relationship between the folk and mathematical astronomical approaches is demonstrated in the matter of prayer times. On the one hand, the great scientist al-Biruni wrote an entire book on shadows without once mentioning tables of prayer times (p. 216), while the folk astronomer Abu Rahiq argues that prayer times must be determined by actual observation without resorting to “this astrology [tanjîm] nonsense.” Yet the tendency of secular Western commentators to ascribe traditionalism to the folk astronomers and rationalism to the mathematical astronomers is called into question by the 15th century astronomer Sibt al-Mardini’s declaration that “the opinion of the muezzins [those who call people to prayer] is less correct than that of the legal scholars and it is the latter that should be used as the basis for the determination of prayer time” (p.230). King also notes the anecdote professing that Umar ibn Abdul Aziz (famous in Muslim history for his piety) preferred determining the times of prayers with an instrument designed by the mathematical astronomers (p. 582).


King bolsters the case for the view that there is a smooth transition between late Islamic and early modern European science (pp. 188-9), although he concedes that there is “no evidence that … any of the later European astronomers were familiar with the Islamic auxiliary tables” (p. 190). 


An important matter is the role of observation in science. It turns out that Ibn al-Shatir, the 14-century astronomer famous for his observational objections to the Ptolemaic theory, was officially a muwaqqit, or timekeeper for a mosque (p. 650) and made an observational critique of the “half arcs of visibility of the sun and stars” (p. 290).


King has traced quantitative estimates “of refraction back to the 11th c. Scholar Ibn al-Haytham.” (p. 793) who’s work in optics is well known for its experimental/observational sophistication. The Muslim concern with the issue of refraction at the horizon repeatedly manifests itself (p. 170, 272, 276f., 355, 792f.).


King demonstrates a strong concern with the development of universality, development of timekeeping tools, both mathematical and instrumentational, that are of use globally and not specific to a particular location or latitude. In this connection he makes special mention of the 14th century instrumentationalist from Aleppo, Ibn al-Sirraj (“the high point of Islamic instrumentation”) and his contemporary from Damascus al-Khalili, a mosque muwaqqit whose work has only come to light since the 1970s. Kahlili’s qibla values are remarkably accurate, usually good to one or two minutes of arc (p. 694).


On the instrumental side King mentions a magnetic compass combined with a sundial to determine direction for fixed latitude (p. 707), a compendium that would work for any of a series of latitudes, and mechanical timepiece from 1225 (p.645).


Also on the mathematical side, King explores the possible relationship among astronomers known to have calculated enormous tables. Najm al-Din al-Misri “compiled a table for any latitude giving the time since the rising of either the sun or any non-circular start as a function of stellar or solar altitude” with 440,00 entries (p. 304).


The 9th century astronomer Habash devised an exact solution for preserving the distance and direction to a central point on a map grid (p. 834). King reviews Safavid (17th c.) world maps centered on Mecca noting that “the first European world maps preserving direction and distance to a central nonpolar location date from the early 20th century” (p 834) and rebuts the critics of his remarkable conclusions (pp. 838 f.) that Habash’s solution is the basis for the Safavid projections and for overlaid directions and distances on maps in the 9th and 11th centuries. These 17th century world maps mandate “a reassessment of Muslim achievements in mathematical cartography.”


The distinction between true and false dawn, once believed to be a modern European discovery, but actually mentioned the traditions of Muhammad, makes a number of appearances in the medieval corpus (pp. 215, 218, 230).


King includes a review of medieval Christian timekeeping, but concludes that “‘science’ is really inappropriate to describe the activities of Christian monks” (p. 856, although King elsewhere notes that the subject of medieval Christian timekeeping has barely had its surface scratched, e.g. p. 871).


King’s analysis contradicts the until-recently dominant view that Muslim astronomers contributed little new to science, but simply preserved ancient Greek knowledge. His exhaustive catalog suggests the degree to which we have still not plumbed Muslim astronomy. His analysis demonstrates that timekeeping was full-blown scientific discipline and the muwaqqits were real scientists in the full sense of the term. Another thing this volume achieves is, in King’s own words, that it “makes nonsense of the popular notion that religion inevitably impedes scientific progress” (p. xvii).


David King has provided us with a magnificent survey of material on medieval Islamic timekeeping. It is an essential resource for anyone interested in this subject and also highly recommended for anyone interested in the history of science in general. The insights on the relationship between folk astronomy and mathematical astronomy would also be of interest to anyone interested in the relationship of science and culture, an emerging subject of interest in our time.

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