Gloria a Rouen

Gloria a Rouen, circa 1690. Fine and extremely rare, silver gilt moon phase astronomical calendar, Louis X1V "oignon" without fusee and with Gloria's worm-screw regulator and power reserve indication. Double body, oignon, polished. White enamel chapter ring with Roman numerals and inner calendar ring (slightly restored on the winding hole border), moon phase aperture on the gilt brass centre engraved with scrolled foliage. Hinged gilt brass full plate with urn pillars, the going train with fixed barrel, 30 hour power reserve indicator, verge escapement, plain steel three-arm balance, short flat balance spring with worm-screw regulator, fine gilt brass Louis XIV cock pierced and engraved with foliage. Signed on the back plate. In good condition. Diam. 54 mm. Notes "Oignons " without fusee are extr emely rare. Jacques Gloria was the first to produce diem at Dieppe, then at Rouen at the end of the 17th century believing that with the increased precision given to watches by use of the balance-spring, he could do without the fusee. For a short period he was followed by several clockmakers at Rouen, Dieppe, Caen and Abbeville. Usually thay are straight-Forward watches without the least complication. So as to overcome the too great variations in force resulting from the unregulated spring as it ran clown, the Rouen clockmakers used only the central portion which supplied a relatively constant force for about 30 hours. This gave rise to the need for a small dial on the bac Read more…