Onésime Dumas "Dépot de la Marine", Movement No. 57, Case No. 57, 100 x 65 x 120 mm, circa 1860

A small marine chronometer with 40h power reserve indicator
Case: mahogany box. Dial: silvered. Movm.: brass movement, 59 mm, chain/fusee, spring detent escapement, bimetallic chronometer balance with 4 screws and 2 weights.

Onésime Dumas (1824-1889) was the nephew of Henri Motel and apprenticed with him. He was also a student with Perrelet and C.A. Berthoud. Dumas took over Victor Gannery's shop in 1851.