This is the first investigation of one of the main interests of astronomy in Islamic civilization, namely, timekeeping by the sun and stars and the regulation of the astronomically-defined times of Muslim prayer. The study is based on over 500 medieval astronomical manuscripts first identified by the author, now preserved in libraries all over the world and originally from the entire Islamic world from the Maghrib to Central Asia and the Yemen. The materials presented provide new insights into the early development of the prayer ritual in Islam. They also call into question the popular notion that religion could not inspire serious scientific activity. Only one of the hundreds of astronomical tables discussed here was known in medieval Europe, which is one reason why the entire corpus has remained unknown until the present. A second volume, also to be published by Brill, deals with astronomical instruments for timekeeping and other computing devices.

This is the first investigation of one of the main interests of astronomy in Islamic civilization, namely, timekeeping by the sun and stars and the regulation of the astronomically-defined times of Muslim prayer. The study is based on over 500 medieval astronomical manuscripts first identified by the author, now preserved in libraries all over the world and originally from the entire Islamic world from the Maghrib to Central Asia and the Yemen.

This volume of 12 studies, mainly published during the past 15 years, begins with an overview of the Islamic astronomy covering not only sophisticated mathematical astronomy and instrumentation but also simple folk astronomy, and the ways in which astronomy was used in the service of religion. It continues with discussions of the importance of Islamic instruments and scientific manuscript illustrations. Three studies deal with the regional schools that developed in Islamic astronomy, in this case, Egypt and the Maghrib. Another focuses on a curious astrological table for calculating the length of life of any individual. The notion of the world centred on the sacred Kaaba in Mecca inspired both astronomers and proponents of folk astronomy to propose methods for finding the qibla, or sacred direction towards the Kaaba; their activities are surveyed here. The interaction between the mathematical and folk traditions in astronomy is then illustrated by an 11th-century text on the qibla in Transoxania. The last three studies deal with an account of the geodetic measurements sponsored by the Caliph al-Ma'mûn in the 9th century; a world-map in the tradition of the 11th-century polymath al-Bîrûnî, alas corrupted by careless copying; and a table of geographical coordinates from 15th-century Egypt.

Recent studies in the history of Islamic science based on the discovery and study of new primary texts and instruments have substantially revised the views of nineteenth-century historians of science. This volume presents some of these ground-breaking studies as well as articles which shed new light on the ongoing academic debate surrounding the question of the decline of Islamic scientific tradition.