Rare F. Luthi Constant Force Regulator, circa 1920

Fine and extremely rare gilt bronze eight day going mantel regulator with constant force escapement. C. Gilt bronze moulded, standing on four bun-feet and glazed four faces and top, the movement inside, supported by a massive pyramidal white stand. D. Silvered with Arabic numerals and subsidiary seconds. Polished steel Breguet hands. M. Brass circular with cylindrical pillars secured by screws, going barrel and constant force escapement, half second beating invar-elinvar pendulum with spring suspension. Signed F. Luthi, Horloger a Paris, on the dial.