A fine and unusual late 18th Century French virgule in a very rare gold and enamel case with invisible hinge. Unusual slim full plate gilt keywind movement with raised resting barrel. Plain sector shaped cock secured by two blue steel screws, polished steel coqueret. Small plain three arm gilt balance with blue steel spiral hairspring, steel regulator with index on the plate. Rare virgule escapement, brass escape wheel. Winding through the white enamel dial, Roman and Arabic numerals, gold beetle and poker hands. Fine pearls set gold and enamel case with glazed gold protective outer. Engraved gold bezels decorated with blue, red and white champleve enamel. Matted gold back with applied three colour gold decoration of an urn within an oval frame. Set with split pearls and champleve enamel in various translucent colours. The edge of front bezel set within a recess of the body of the case with no discernable sign of a hinge. Opening the bezel by depressing a button in the pendant reveals the hinge to be unusually placed at three o’clock, set close to the movement. The small crescent of the bezel beyond the hinge moves below the recess in the body of the case. Glazed gold outer case to protect the watch.