Fine French 18K gold and guilloché enamel pocket watch Circa 1790

Gold open faced verge pocket watch 
–
A very fine French, 18K gold and enamel pocket watch, circa 1790. A Louis XVI case, the bezel with zig-zag white enamel decoration and dark blue enamel triangles set with gold paillons, the back with a fine Royal blue guilloché enamel panel decorated with a central gold paillon rosette and leaf and flower paillon border, outer border decorated to match the bezel. White enamel dial with radial Arabic numerals, outer dot minute track with Arabic fifteen-minute numerals. Gold fleur-de-lys hands. A   hinged gilt brass full plate movement with tapered cylindrical pillars, fusee with chain, verge escapement, potency with screw adjustment, gilt brass continental cock with polished steel end-piece, silvered regulation dial. Dial and movement signed.
–
Diameter: 45 mm
–
Signed: Hessen  Paris
–
The fine guilloché enamel panel on the back of the present watch is decorated in a very similar manner to the enamels made for the watches of Jaquet Droz. André Hessen Worked in Paris between 1775 and 1791.