This article addresses the contents of twelfth-century fascicle contained in MS Lyon, Palais des Arts, 45, which is largely devoted to texts on computus and astrolabe. Included among latter are 24 anonymous chapters astrolabe use, appear stem from a previously unrecorded translation Ibn al-Ṣaffār’s Kitāb fī-l-ʿamal bi-l-asṭurlāb (Book Uses Astrolabe). would make Lyon manuscript third such come ...