French gold, enamel, diamond set à tact brooch watch Circa 1800

Gold cylinder brooch watch
–
A rare French 18 carat yellow gold, enamel and diamond set médaillon montre à tact, circa 1800. The front cover with translucent dark blue enamel over a sunburst effect engine turning, eccentric ellipse pattern. Revolving back cover with arrow tact hand set with rose cut diamonds and with finely reeded edge. The reeded band set with eleven rose diamond touch pieces, attached to an enamel and pearl set brooch. Gold cuvette with apertures for the dial and the winding holes.
–
Small eccentric silvered dial with Arabic numerals and outer minute track, mounted on the barrel bridge and blued steel Breguet hands. Fire gilded souscription calibre with centre barrel wound only from the front, five wheel, 45 hour going train controlled by ruby cylinder escapement with brass three arm balance with flat blued steel balance spring, index regulator.
–
Diameter: 82 mm
–
Total: 133 x 133 x 110 mm
–
Signed: Breguet  Paris
–
One diamond and one pearl are missing