VACHERON & CONSTANTIN PRODUCED IN 1906 N° 190605 Open Face" pocket watch in 18K (750) yellow gold with complications: perpetual calendar, moon phases, single-pusher chronograph and minute repeater. Case: round, basin-shaped, hinged, composed of four elements, smooth reverse. Bezel: snap-on, hinged. Slide at 9 o'clock to activate the striking mechanism, correctors at 3 and 6 o'clock on the case middle for quick calendar adjustment and push-button for chrono activation integrated into the crown. Yellow gold case, engraved : Vacheron & Constantin Genève Minute repeater Chronograph Minute counter Chronometer Moon phases Perpetual Calendar Dial: silvered, black enamelled "Breguet" hour-markers, railway track and external 1/5th of a second minute graduation, blued steel "pear" hands. Four auxiliary dials: - 12 o'clock: 48 months over 4 years, 30-minute chrono counter - 3 o'clock: date - 6 o'clock: phases and ages of the moon, small seconds - 9 o'clock: days of the week (in French) Movement: mechanical, lever escapement, cal. RA 18''', bimetallic balance wheel, end-curve balance spring, micrometric swan-neck adjustment, column wheel, 39 jewels, crown winding and time setting. Two hammers on gong. Dial and cuvette signed. Numbered 190605. Diameter: 55 mm. Gross weight: 165.29 g. Including : Vacheron Constantin Certificate of Authenticity. Provenance : Acquired by descent.