English rare early small ship’s chronometer Circa 1788

Rare ship’s chronometer by Thomas Earnshaw
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A rare and early small English ship’s chronometer Of the 6th Sort, circa 1788.
The case is a mahogany box, with a round window, case key, brass gimbals and bowl, and a two-body. The signed, numbered, enamel dial, has radial Roman hours, auxiliary seconds, and gold spade hands. And the 42 mm, gilt, brass movement, has screwed chatons, moulded pillars, chain/fusee, spring detent escapement according to Thomas Earnshaw, bimetallic Z chronometer balance with two screws and two weights, blued helical balance spring with both sides passing terminal curves, fine engraved balance cock, and chatoned diamond endstone on balance.
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Diameter watch: 42 mm
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Dimensions box: 113 x 60 x 113 mm
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Signed: Thomas Earnshaw, London, Invt. et Fecit