Ca. Ø108mm, original brass case, screwed, under the rim is the start/stop mechanism, case, movement mounting and movement with matching number 188, very fine chronometer movement, signed and numbered, decorative finish, conical steel movement pillars, chain/fusee, pivoted detent chronometer escapement in manner of Berthoud, front winding, stoppable seconds device, bimetallic four-arm chronometer balance with 4 movable weights, finely adjustable hairspring mounting with 4 adjusting screws, blued conical hairspring, balance with endstone, silvered dial with Roman numerals, blued steel hands, in working order. In our opinion, this rarity is in original condition. The dial is unfortunately very aged. However, with a magnifying glass the original signature 'Henri Motel, Horloger de la Marine Royale' can be seen, above it in an arc 'Dépôt de la Marine'. Jean-Francois Henri Motel was Louis Berthoud's best student and inherited his company as chronometer supplier to the French Navy. Many of his ship chronometers were later converted into deck watches for the navy. This chronometer No.188 still has the original start/stop mechanism, which is no longer present in most known Motel chronometers!