A rare perpetual wall calendar with two volvelles, produced for the Dutch market, displaying the month “Maende”, days of the week “tage”, date, Zodiac signs “Loop van de Sonne”, time of sunrise and sunset “De Opgaende Sonn ten …Uren De Nedergaede Sonn te … Uren”, length of day and night in hours “Langhte van den Dage … Langte van de Nagt”, and important feast days for the month “De Heylig Daghen”, in accordance with the volvelle settings.

The instrument maker, Veit Balthasar Henning (1706-1762), also published an important illustrated instrument book in Nuremberg in 1756, ‘Sammlung nützlicher Machinen und Instrumenten nebst deren Erklärung aus dem Französischen, Englischen und anderen Sprachen ins Teutsche übersezt’, which went through several editions, all of which are rare.