An Empire longcase regulator, with equation of time, year calendar and remontoire, by Louis Berthoud, Paris, dated 1811
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".