Rare Swiss 18K gold Chronomètre Royal watch Circa 1910

Gold ankerchronometer by Vacheron & Constantin
–
A fine, keyless-winding Swiss 18K gold pocket chronometer, Chronomètre Royal, with open face, in almost new condition, circa 1910.
Round shape 18K gold case, on the back a radiant décor, guilloché with a sunray motif. Signed enamel dial with Arabic numerals, outer minutes track, subsidiary dial for the seconds, and blued steel hands. Gilded brass movement with going barrel, gold screwed chaton (setting) on the central wheel, straight-line lever escapement, compensated balance with gold poising screws and blued steel hairspring with a terminal curve, index regulator with swan-neck spring, and micrometric screw. Dial, case and movement signed.
–
Diameter: 57 mm
–
Weight: 136 g
–
Signed: Vacheron & Constantin Genève Chronomètre Royal