Masterly account of long and colorful history of sundials, with practical instructions for building your own. Formulae, rare dials, mottoes, and much more. 104 figures. 51 plates.

This volume deals with the determination of the times of Muslim prayer and the direction towards the Kaaba in Mecca (Arabic qibla) in a little known astronomical tradition of the Islamic Middle Ages. It presents an edition, translation, and explanation of selected chapters from three of the most important folk astronomical treatises, written by al-Aṣbaḥī (Yemen, 13th c.), Ibn Raḥīq (Hejaz, 11th c.), and al-Fārisī (Yemen, 13th c.). The first part introduces the authors and their works and describes the relevant religious and astronomical background. The second part comprises the edition of the selected – and now for the first time published – chapters of the three works and a German translation. The third part contains a lexicographical survey with basic astronomical, religious, and related information, and a commentary on each chapter. The fourth part gives an overview of the topics dicussed.

"Brief table of contents of vols. I-XX" in v. 21, p. [502]-618.

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.