A gilt-brass mounted japanned grande sonnerie mantel clock with alarm, Robert & Courvoisier, Switzerland, circa 1790

7½-inch convex enamel dial signed Robert & Courvoisier with concentric alarm hand, the square plated trip-repeating movement No.8390 with verge escapement and silk suspension, the strike work mounted on the backplate and sounding on two top mounted bells, pull wind alarm, the waisted case with concave sided cresting surmounted by an urn, decorated overall with gilt sprays on a black ground and outlined with foliate  mounts