ETIENNE TAVERNIER
"The Magic Key"
Gold watch key with semi-automatic calendar
Round case, double-sided with double date indications on one side on enamel dial and phases and ages of the moon on the other, the pendant with a ring.
Mechanism that engages when the key is cocked, the indications of the month and days of the week are triggered, as well as the phase of the moon that moves position.
Height 34 mm
Diameter 18 mm
Gross weight 9 gr
A similar model is illustrated in the catalog of the collections of the Patek Philippe Museum (Inv. K-50), Volume IV, p. 255, The Emergence of the Portable Watch, Peter Friess.