French platinum and sapphire-set keyless lever watch Circa 1910

Platinum, sapphire-set dress watch
–
A very fine and elegant, thin French platinum and sapphire-set keyless lever dress watch, circa 1910. Frosted gilt movement, 19 jewels, straight-line lever escapement, cut-bimetallic compensation balance with a blue steel Breguet balance spring. A matte silver dial with Breguet hours, an outer minute track, the centre guilloché, guilloché subsidiary seconds and blued steel fancy hands. An engraved initial on the case back, the band and band of the bow are sapphire-set. Dial signed, case numbered.
–
Signed: J. Chaumet
–
Diameter: 42 mm
–
Thickness: 5.5 mm