The work of Lorenzo della Volpaia, this small nocturnal consists of overlapping disks showing the days and months of the year. It is fitted with indexes and set for latitude 43° (approximately that of Tuscany). The verso is engraved with a horary quadrant carrying the "Tabula Solis motus" [Table of the motion of the Sun], indicating the Sun's entrance into the zodiac signs. Provenance: Vincenzo Viviani bequest.