The twin sisters Agnes Lewis (1843-1926) and Margaret Gibson (1843-1920) were pioneering biblical scholars who became experts in a number of ancient languages. Travelling widely in the Middle East, they made several significant discoveries, including one of the earliest manuscripts of the Four Gospels in Syriac, a dialect of Aramaic, the language probably spoken by Jesus himself. Their chief discoveries were made in the Monastery of St Catherine on Mount Sinai. This work is a list of the monastery’s manuscripts in Arabic compiled by Margaret Gibson in 1893 and first published in 1894. Written in Greek for use by scholars and for the monks themselves, this fascicule provides a careful document of the monastery’s Arabic pages, their physical state and content. Illustrated with photographs of the catalogued works, this text will be of interest to scholars in Arabic Christianity and Middle East monastic history.