English gold pair-cased rack lever pocket watch Circa 1812

Gold watch with rack lever escapement by Anness
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A fine and very rare English 18 carat gold pair cased pocket watch with rack lever escapement, hallmarked London 1812. Hinged, frosted gilt full-plate movement with cylindrical pillars, jewelled to the third, fusee and chain, Harrison‘s maintaining power, rack lever escapement with large brass escape wheel, three-arm steel flat-rim balance with flat balance spring, diamond endstone, single-footed foliate engraved cock, regulator arm with engraved scale on the backplate. Off-white enamel dial with Arabic numerals, outer minute divisions and original gold pear hands. The case by William, polished outer case, master mark WM, the inner case also polished, gilt brass dust cap.  Movement signed.
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Diameter: 53 mm
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Signed: Anness Cheapside London
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The rack lever escapement was patented by Litherland in 1791 and was used by both Liverpool and London makers during the first quarter of the 19th century. This piece is rare due to the gold pair case, as most rack lever watches were made with silver cases.