Exceptional Discoveries: The Olmsted Complications Collection
A.P. Walsh, London
Retailed by Sam Hammond: A yellow gold open-faced chronometer watch with duo-in-uno hairspring and up-and-down indication, No. 319, Circa 1865
No reserve
Lot Closed
December 10, 06:18 PM GMT
Estimate
800 - 1,200 USD
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Read more.Lot Details
Description
Movement: spring detent escapement, duo-in-uno blued steel helical hairspring, free-sprung regulator, diamond endstone, gilt three-quarter plate movement, jeweled to the center carried in gold chatons, bi-metallic compensation balance, backplate signed A.P. Walsh, 5 George Str, Euston Road, London, No. 319
Dial: white enamel dial, Roman numerals, subsidiary dials for constant seconds and up-and-down indication, signed Sam Hammond, New York, 319
Case: 18k yellow gold engine-turned case centered by blank rondel, pendant stamped with casemaker's initials FA, case stamped with London Hallmarks for 1865, casemaker's initials AS, and numbered 319
Signed: movement signed by maker, dial signed by retailer, case and cuvette stamped AS
Diameter: 53 mm
Weight: approximately 134.94 g
A celebrated watch and chronometer maker, as well as a noted springer, Arthur Paul Walsh (1815-1896) was apprenticed to T.F. Cooper before establishing himself as a respected figure in the horological trade. He later partnered with Robert Oliphant as a tool dealer on Frith Street, Soho, before relocating his business to George Street, Euston Road.
Walsh is credited with the invention of the duo-in-uno balance hairspring—a significant advancement in chronometer design. This innovation allowed the overall height of a helical spring to be reduced, conserving vertical space within a pocket chronometer movement. The duo-in-uno comprises multiple coils shaped like a helical spring, all of a uniform diameter equal to the outer diameter of the flat spiral portion, achieving both precision and compactness.