This book deals with the mathematical sciences in medieval Islam, and focuses on three main themes. The first is that of the translation of texts (from Greek into Arabic, then from Arabic into Latin), and close attention is paid to terminology and comparative vocabulary. The other themes are those of the technology of the sphere and of astronomical instruments, which are treated both from the mechanical and mathematical point of view. Several of the articles combine these themes, for instance the study of the self-rotating sphere of al-Khazini (12th century) or that on the transmission of spherical trigonometry to the West. Four articles also contain substantial texts, with translation and commentary.