This manuscript is a collection of texts on mathematical astronomy and the natural sciences dating from early in the ninth century. The illuminations are mainly of astronomical content and are based on models from late antiquity. They include the occupations of the 12 months, the earliest surviving medieval illuminations of this type (folio 91 verso); an astronomical map (folio 113 verso); the constellations (folios 115 verso−121 recto); and the 12 winds (folio 139 recto). The manuscript was copied in Salzburg, apparently from a northern French exemplar, and was presumably in the possession of the Benedictine monastery of Saint Emmeram in Ratisbon (present-day Regensburg), Bavaria, during medieval times.