English 18k gold quarter repeating pair-cased pocket watch Circa 1733

Gold and shagreen cylinder pocket watch
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A fine English, quarter repeating, pair-cased, 18K gold and shagreen pocket watch with early use of the cylinder escapement, circa 1733. Accompanied by an additional gold and enamel outer case, custom made circa 1770. With London hallmark for 1733. Outer: the bezel and back are overlaid with shagreen and decorated with a gold pin work monogram and borders. Inner: maker’s mark WW, with foliate pierced and engraved band. Gilt brass dust cover. Additional case: circa 1770, maker’s mark DA, the bezel decorated with a dark blue enamel Greek-key pattern and pie-crust borders, the back engine-turned and with a dark blue enamel monogram and further initials suspended from a ribbon, Greek-key border to match the bezel.
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White enamel dial with radial Roman numerals, outer minute track and Arabic five-minute numerals. Blued steel beetle and poker hands. A gilt-brass full-plate movement with baluster pillars, fusee with chain, cylinder escapement with brass escape-wheel, three-arm steel balance with flat balance spring, diamond endstone, pierced, chased and engraved balance cock, silver regulation dial, repeating with two hammers on a bell in the back of the case activated by depressing the pendant. Movement and dust cover signed.
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Diameter: 49 mm
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Signed: William Threlkeld  London
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The inner case of the present watch is stamped with the London date letter mark for 1733 and retains its original outer case. A further outer case dating from circa 1770 has been custom-made for this watch and can be used as an alternative. Many watches were provided with replacement outer cases to keep abreast of fashion. The old case was usually discarded; it is unusual for the original outer case to have survived. The cylinder escapement was improved or invented by George Graham in 1726 and used by him in preference to the verge from this date onwards. The present watch is a good example of the early adoption of the cylinder escapement by another maker working in the same area as Graham’s workshop.