A French marine chronometer (Captains clock) ‘Depot de la Marine no.223 A French so called ‘Captains clock’. A fine French chronometer, ca. 1860. Signed on the dial: ‘Depot de la Marine' and 'Dumas no.223’. The 30 hour going movement with Earnshaw’s spring detent escapement. Its silvered engraved dial with black lettering and blued steel ‘Breguet style’ hands includes chapters for the hours, minutes and seconds as well as an up/down (réserve de marche) indicator. The whole is contained in a nicely colored coromandel veneered two tier box of which the lower tier provides a box to store the winding key. • Dimensions: H 11 cm B 13,2 cm D 10,2 cm • The maker: Onésime Dumas (1824-1889) was Louis Berthoud’s grandson and the nephew of Henri Motel. He was placed by the Government, in 1837, as pupil to Louis- Frédéric Perrelet, then in charge of the Ecole des Horlogers de la Marine, since 1832. When Perrelet resigned in December 1839 for health reasons, and Charles-Auguste Berthoud was appointed as his successor by the Ministre 295 de la Marine to complete the instruction of his pupils, Onésime Dumas already had two and a half years of apprenticeship. When he left the school, he worked for a short period with Motel. Therefore, the very first chronometers made by Onésime Dumas were very similar to those produced by Louis Berthoud and later by his two sons. Working with his uncle, he made a few chronometers with the highly refined caliber which ensured the fame of Henri Motel. He then succeeded to Gannery in Saint-Nicolas d’Aliermont, in 1851. The chronometer No. 421, produced the same year, carries both their signatures. He employed between 12 and 15 craftsmen and exhibited precision horology at Rouen in 1856. He signed "Dumas Successeur de Gannery". His name was given to a new full plate caliber, very much inspired by the English style, not as elegant nor refined as that of Motel, but less expensive to produce, robust and reliable. It was adopted by most other French makers. • Literature: J.-C. Sabrier: "La Longitude en Mer à l’Heure de Louis Berthoud et Henri Motel", Antiquorum Editions, Genève 1993.

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