This small astrolabe comprises three tympanums for latitudes 40°/45°, 42°/36°, and 50° (corresponding to Spain, Italy, and France). There is a rete (extensively damaged) and an alidade. The limb of the mater is graduated and divided into 24 parts. The back is inscribed with the zodiacal calendar and the shadow square for surveying. Provenance: Medici collections.