A superb and very rare Empire mahogany masterpiece longcase regulator of month duration, with equation of time, year calendar and remontoire signed on the massive nine rod gridiron compensated pendulum Louis Berthoud, Horloger de la Marine. The extremely fine white enamel convex dial signed and dated Dubuisson 1811. The dial painted with signs of the zodiac, months and days of the year indicated by blued steel hands, blued steel sweep centre second hand and blued steel arrow head minute hands indicating Greenwich mean time, with beautifully pierced gilt brass hour and minute hands indicating solar time. The movement for the remontoire mounted above the dial, has two massive spring driven going barrels to power the twin weight remontoire. With dead beat escapement with fine adjustment to the crutch piece for the massive nine rod gridiron pendulum, with knife edge suspension suspended from a substantial brass block secured to the top of the case, with enamel plaque on the pendulum to indicate temperature scale. The finely proportioned case with concave mouldings to the detachable top, the hood door with fine gilt bronze bezel and convex glass, the trunk with a glazed door and the base with raised rectangular panels and plain skirt
Paris, dated 1811
Height 208 cm.
Pierre-Louis Berthoud (1754-1813), known as Louis was a very important clockmaker and an ingenious scientist. His father, Pierre was a clockmaker but Louis trained under his highly esteemed uncle, Ferdinand Berthoud (1727-1807) and later succeeded Ferdinand's business. Like his uncle, Louis was particularly interested in precision horology specialising in making regulators, over 150 chronometers as well as clocks and watches. He was appointed as clockmaker to the Observatoire and to the Bureau de Longitude. He won a gold medal at the Paris Exposition, l'an X (1800/1) and wrote 'Entretiens sur l'horlogerie".