Swiss gold chronograph pocket chronometer with register Circa 1906

Gold chronograph with register by Vacheron & Constantin
–
A very fine Swiss 18-carat gold open faced pocket chronometer with chronograph and register, circa 1906. High-quality ankerchronometer movement with chronograph, chronometer balance, fine adjusting device. White enamel dial with Arabic numerals, 30-minute counter, subsidiary seconds and rose gold hands. Case engine-turned. Dial signed, case numbered, cuvette signed and additionally inscribed Chronomètre Royal, movement signed and numbered. Comes with the original box.
–
Diameter: 51.5 mm
–
Weight: 108 g
–
Signed: Chronomètre Royal Vacheron & Constantin Genève
–
This watch is probably the only Chronometer Royal with an additional complication known.