Unique English gold verge with pietra dura mosaic Circa 1750

Pietra dura verge in pair cases by Martineau
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An early and unique English gold pair cased verge pocket watch with pietra dura mosaic and date and metal outer case, circa 1750. Fine English verge escapement, worm gear, very unusual pillars and plate decoration. Gold champlevé dial with Roman hours and Arabic five minutes, aperture for the date, blued steel hands. Decorated with enamel and filigree gold and mother-of-pearl pietra dura mosaic, the back with central butterfly, 18 carat gold inner case, case maker’s mark. Dial and movement signed. In working order.
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Diameter: 53 mm
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Weight: 107 g
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Signed: Martineau London
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This watch is most likely by Joseph Martineau Senior. He was known as an important and Royal London watchmaker and probably died around 1770. His watches can be found in numerous museums such as the Metropolitan Museum of Art in New York or the ‘Mathematisch Physikalische Salon’ in Dresden. Typical for Joseph Martineau Senior are his fantastic cases, often with stone inlays or special leather and enamel decorations. This piece is probably one of a kind.