Important Collectors’ Wristwatches, P...

New York, The Grand Havana Room, Sep 20, 2006

LOT 266

"8-Day Mantel Chronometer" Thomas Mercer, London & St. Albans, patent No. 21.257/22, No. 596. Made circa 1950. Unusual and rare, 8-day going, mahogany mantel chronometer with 60-second circuit breaker, 8-day power reserve sector and platform detent chronometer escapement.

C. Rectangular, mahogany, glazed brass hinged bezel. D. Silvered, radial Roman numerals, outer minute track, subsidiary seconds and aperture below 12 to view the seconds wheel and electrical contacts, power reserve indicator above 6. Blued steel ?spade? hands. M. Rectangular, brass full plate, 4 massive ring turned pillars secured by screws, 2 insulated screwed-down terminals on the back plate for the electrical connection, ?oeil-de-perdrix? decoration, fusée and chain, Harrison?s maintaining power, Earnshaw's spring-detent escapement mounted on a large platform and fitted with start/stop wheels to lock the balance wheel via a lever in the dial, free-sprung cut bimetallic compensation balance with 2 cylindrical brass temperature adjustment weights and meantime adjustment nuts, free-sprung helical balance spring with terminal curves, escapement jeweled. Dial signed and numbered. Dim. 28 x 22.5 x 13.5 cm