Indice: Preface. Statement on previous publication of parts of this work. Bibliography and bibliographical abbreviations. Pt. 1. A survey of tables for timekeeping by the Sun and stars. Pt. 2. A survey of tables for regulating the times of prayer. Pt. 3. A survey of arithmetical shadow-schemes for time-reckoning. Pt. 4. On the times of Muslim prayer. Pt. 5. On the role of the muezzin and the muwaqqit in medieval Islamic societies. Pt. 6a. Universal solutions in Islamic astronomy. Pt. 6b. Universal solutions to problems of spherical astronomy from Mamluk, Syria and Egypt. Pt. 7a. The orientation of medieval Islamic religious architecture and cities. Pt. 7b. Architecture and astronomy: the ventilators of medieval Cairo and their secrets. Pt. 7c. Safavid world-maps centred on Mecca. Pt. 8. Aspects of practical astronomy in mosques and monasteries. Pt. 9. When the night sky over Qandahar was lit only by stars. Indexes