Claude François Bailly used to work in Morbier from 1766 to 1774. FERDINAND BERTHOUD 1727-1807 Ferdinand Berthoud, Julien Le Roy and Breguet are the three most famous names in French clockmaking. Berthoud was born at Plancement, commune de Couvet, canton de Neuchâtel, Switzerland, on 19 March 1727. His father, an architect and magistrate of the Val de Travers, had at first destined him for an ecclesiastical career, but as at a very early age he showed interest in mechanical matters, he decided to have him taught clockmaking. At the age of 14 Ferdinand was apprenticed to his brother Jean Henri. When he vas 19, he borrowed 200 livres to go to Paris, where another brother, Jean-Jacques, a designer, was already established. It is thought that he worked for Julien Le Roy for some time, before setting up his own workshop in the rue du Harley, not far from the house in which the latter was still working. At this time he made the acquaintance of Pierre Le Roy, 'ho, throughout his career, vas his only rival. In 1752 lie presented to the Academy of Science an equation watch with a perpetual calendar. His knowledge of mathematics and physics, together with his ability to impress the authorities with his capacities, enabled him in 1764 to obtain the office of "Horloger de la Marine Royale" (Clockmaker to the Royal Navy), with an annual pension of 3000 livres, which ensured, witb his other activities, an average income of 7,500 livres a year. By order of the King, he vent twice to England, with Camus and Lalande, to examine John Harrison's marine docks. Although he was able to study docks number 1, 2, and 3, Harrison refused to show him dock number 4. After having learnt some English, during his second journey, in 1766, Berthoud obtained from Thomas Mudge, who, with Kendall and Matthews, belonged to the committee responsible for examining and giving an opinion concerning this famous time-piece, the information he reeded concerning Harrison's watch number 4, which allowed him to enlarge his own researches. He then undertook the construction of his own marine clocks 6 and 8, which were taken to Rochefort, and handed over on 3 November 1768 to Eveux de Fleurieu, commanding the frigate Isis, who, assisted by the astronomer Pingré, vvas to test them during a voyage on the high sens. The precision instruments that he invented enabled Berthoud to perfect a rigorous experimental technique, adopted by all his successors, and particularly by his nephew Pierre Louis Berthoud. He can be criticised for having sought to appropriate the important discoveries concerning marine watches made by Pierre Le Roy, his celebrated rival. However, it would be unfair to think that Ferdinand Berthoud's considerable quantity of work did not contribute to the progress of chronometry. We owe to him many experimental marine watches, most of which, purchased by the Government, are preserved in the Musée National des Techniques (C.N.A.M.), Paris. They include watches and docks with equation of time, seconds watches, and superb astronomical longcase clocks fitted with compensated pendulums which he invented. All the timepieces that he made show his great dexterity, and the exceptional quality of his execution. He left many documents on clockmaking, printed at State expense, in which his experiments and inventions are described in great detail. From a small pamphlet, published in 1759 under the title L'art de conduire et régler les pendules et les montres à l'usage de ceux qui n'ont aucune connaissance d'horlogerie, which vent into six editions between 1759 and 1836, without counting Henri Robert's edition of 1841 and the numerous translations into different languages, to his Supplement au traité des horloges rnarines...published in the year of his death, 1807, the written work of Ferdinand Berthoud covers more than 4000 pages, illustrated by over 120 plates, engraved from drawings by the author. He died on 20 June 1807, in his property at Groslay, near Montmorency, leaving no children. He married twice, firstly Mademoiselle Chatri of Caen, and then Mademoiselle Dumoustier of Saint Quentin. Ferdinand Berthoud was appointed, in succession, Clockmaker to the Navy, Member of the Institute of France, Fellow of the Royal Society of London, and Chevalier of the Légion d'Honneur. The State paid him an annual pension of 3000 livres until the day of his death. His name figures among those of great men engraved on the façade of the Palace of Industry. His chief pupils were Jacques and Vincent Martin, and particularly his nephew Pierre Louis Berthoud.