Thomas Earnshaw, London, Invt. et Fecit, Movement No. 334/2387, 113 x 60 x 113 mm, circa 1788

A rare and early small ship's chronometer "Of the 6th Sort"
Case: mahogany, round window, case key, brass gimbals and bowl, two-body. Dial: enamel, signed, numbered, radial Roman hours, auxiliary seconds, gold spade hands. Movm.: brass movement, gilt, 42 mm, screwed chatons, moulded pillars, chain/fusee, spring detent escapement according to Thomas Earnshaw, bimetallic "Z" chronometer balance with 2 screws and 2 weights, blued helical balance spring with both sides passing terminal curves, fine engraved balance cock, chatoned diamond endstone on balance.