French gold open faced complicated pocket watch Circa 1920

Gold keyless lever calendar watch
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An exceptional and rare French 18 carat yellow gold open faced pocket watch with full calendar and moon phase made by L. Leroy & Cie in Paris, circa 1920. It has a mechanical crown winding movement with a lever escapement and micrometre screw adjustment, signed L. Leroy & Cie. The cream guilloché dial, signed L. Leroy & Cie, features a Clou de Paris patterned centre, black Breguet numerals for the hours, an outer minute track, and subsidiary dials for the months at 12 o’clock, date at 3 o’clock, days of the week at 9 o’clock, and moon phase combined with a seconds dial at 6 o’clock. It has blued steel Breguet style hands.
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The timepiece is housed in a round 18 carat solid yellow gold open faced case stamped with an eagle head hallmark for 18K gold, an S key G master hallmark, and traces of a Le Roy hallmark. It features date function correctors on the caseband, an oval suspension bow, a fluted winding crown, and a plain polished back cover decorated with a white enamelled G.W monogram. The watch is accompanied by its original signed fitted presentation box and a 40 cm platinum chain weighing 16.2 g.
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Diameter: 50 mm
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Weight: 103 g
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Signed: L. Leroy & Cie
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Leroy and Cie
The French watchmaking house L Leroy and Cie was renowned from the late nineteenth century into the twentieth century as a specialist in marine precision chronometers and intricate watch complications. Based at the prestigious Boulevard de la Madeleine in Paris, the firm gained immense international fame as the official and elite supplier to the French Navy under the title Horlogers de la Marine. Although the owner purchased the workshops and archives of their long standing competitor Le Roy et Fils in 1845, the brand maintained its unique technical identity under Louis Leroy’s leadership. The firm’s mastery was demonstrated globally at the turn of the century with the creation of the legendary Leroy Dynamic. This stood for decades as the most complicated portable timepiece ever constructed in horological history.
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Clou de Paris (French for Paris nail) is a traditional decoration technique in watchmaking that consists of a pattern of small, regular pyramid shaped structures. In English, this design is commonly referred to as a hobnail pattern. It is one of the most iconic forms of guillochage (the mechanical or manual engraving of metal surfaces).