English timepiece with Arnold type escapement Circa 1782

Gilt timepiece with mean solar and sidereal time indication
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A rare English gilt brass timepiece with an Arnold type pivoted detent escapement and sidereal time indication, circa 1782. Gilt full plate movement engraved with swags, foliage and trophies of war, a chased and engraved balance cock fixed with two screws, an Arnold type pivoted detent escapement, engraved gilt brass three arm balance, a flat steel spring, an adjustable bimetallic compensation curb, friction rollers to the top and bottom balance pivots, a fusee with Harrison’s maintaining power. The front of white enamel with three fixed subsidiary dials and three rotating ones showing hours, minutes and seconds, the mean solar time is indicated by the fixed dials and the sidereal time by the inner dials which contra rotate. An engraved case mounted on a 19th century stand made in the manner of Thomas Cole with a mirrored panel to the base. Dial signed, movement signed and numbered.
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Diameter: 115 mm
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Signed: Geo Margetts London
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This watch is the only known pivoted detent chronometer recorded by Margetts. It appears to date to 1782 or 1783 and is thought to have been supplied by John Arnold, just before he and Thomas Earnshaw introduced the spring detent escapement. 

George Margetts, 1748-1808, was born in Oxfordshire and was made free of the Clockmakers’ Company in 1779. He was elected to the Livery of the Clockmakers’ Company in 1799.  Though little is known about his life, short of the belief that he died in an insane asylum, he remains remembered for his astronomical watches and eight day chronometers.

Margetts, was a petitioner to the Board of Longitude on several occasions with the goal to secure funds for his various projects that related to finding longitude and improvements in astronomy.  The Board did grant him some funding as did the East India Company. The latter he supplied with tables to assist navigators.