Of cylindrical form with a pull off lid, ribbed sides. The lid with a rotating disc with rotating outer calendarium perpetuum ring engraved for the days of the week, the outer band with the days of the month. Twelve readout windows defined by its rotatable disk, month of the year with its number of days, tabulation of the important saints’ and feast days in the month, sun’s Zodiacal position, length of day, length of night, time of sun rise, and time of sunset. Engraved symbols of the zodiac, engraved throughout in Latin. The rating ring with flat chased foliate scrolls against a textured ground. Unmarked. Diameter - 15.8 cm / 2.3 inches Weight – 75 grams / 2.41 oztNotes:Similar engraved foliate scrolls to a German perpetual calendar aide memoire is in the collection of the Victoria and Albert museum (M.137-1923)