JOHN ROGER ARNOLD, LONDON, NO. 376, A MAHOGANY MARINE CHRONOMETER WITH Z BALANCE AND ARNOLD’S SPRING DETENT ESCAPEMENT

The associated two-tier mahogany case with oval brass escutcheon and two drop carrying handles, baize-lined interior with later square section outer gimbal ring, thumb screw locking pin and original brass bowl, the 3 1/8in circular silvered dial, with convex glass, signed ARNOLD, LONDON, seconds subsidiary ring above the VI and numbered 376, the movement signed Jn. R. Arnold, London, Inv.t et Fecit, No. 376, the free undersprung Z balance with diamond endstone, blued steel helical hairspring, chain fusee movement with maintaining power, with a brass winding key

The box 17cm square

COMPARATIVE LITERATURE:

Jonathan Betts, Marine Chronometers at Greenwich, Oxford, 2017; p. 272-274, details John Roger Arnold No 379.

Hans Staeger, 100 Jahre Präzisionsuhren von John Arnold bis Arnold & Frodsham 1763-1862, Stuttgart, 1997.

Audrey Mercer, John Arnold & Son, London 1972, records the mainspring of No. 371, as scratch marked 1811, p. 152.

Condition report

The case and possibly the gimbal ring are associated.  The chronometer has been restored at some point, perhaps 20 years ago?  The case has been repolished and the brass relacquered. There is a filled hole in the side of the brass bowl. The movement appears clean and intact, although it does not run for more than a few seconds.  It may just be very dry?  There is an associated brass key.