JULIEN LE ROY 1686-1759 Julien Le Roy is one of the clockmakers who have contributed most to the progress and the reputation of French watch and clockmaking. Born in Tours on 6 August 1686, he came to Paris in 1699 and was received master in 1713, after having been apprenticed to Le Bon. In the following year he married Jeanne Lafons and established himself in the rue du Harlay. Member, then Director of the Société des Arts, he improved almost all branches of clockmaking, and many important inventions in the realm of time measurement are owed to him. In 1717, Julien Le Roy presented to the Royal Academy of Sciences, an equation clock which showed true tinte, the place of the sun, and its declination. Appointed Clockmaker to the King in 1739, he had his private quarters in the Louvre Galleries. His inventions concerned, among other things, turret clocks, equation-clocks, and pull-repeat mechanisms which, then hidden under the dial, were arranged on the back- plate so as to make them more accessible and ensure easier adjustment and maintenance. He developed a double anchor escapement, with dimensions suitable for making the vibrations isochronic, by making the arms the same length as the radius of the wheel. However, his most important discoveries concerned watch mechanisms. The adjustable potence for the crown wheel considerably improved the functioning of verge escapements, and the steel end-piece (coqueret)which allowed oil to be retained in the balance pivots to diminish frictional force, was quickly adopted by other watchmakers. Inventor of dumb repeating watches, he had the idea in 1740 of a new arrangement which allowed the arec for the repeating work to be enlarged. This invention, called à bâte levée, was also adopted by his fellow clockmakers. In 1755 he invented a small anchor escapement used as a regulator for the repeating train. The dates for these two inventions are engraved on the dial plates.They are a useful aid for dating the watches more accurately. In 1715 he was introduced by William Blakey senior to the English clockmaker Henry Sully. They became very friendly and worked together until the death of Sully in 1728, participating jointly in the reconstruction of the Société des Arts and published an enlarged posthumous edition of his book Règle artificielle du temps (1737). He contributed to the Grande Encyclopédie by writing several articles on clockmaking together with his son Jean-Baptiste, the Academician. His springs were mostly made by Blakey and from 1731, Antoine Nicolas Martinière and Nicolas Julien supplied him with dials. On account of his fame, he was able to break loose quite early from the usual commercial circuits to sell his production directly, without however neglecting the marchands merciers, of whom Lazare Duvaux was the most important. He usually chose the cases for his clocks and watches, often designed by himself, unless the client imposed his choice. He had four apprentices: Antoine Campary in 1723, René Sénard in 1741, Louis David Carré in 1743, Jean Vernède in 1747 and Joseph Sylvestre in 1750. to be continmd 106 Among his principal compagnons and colleagues, it is worthwhile to mention: his sons, the eminent Pierre and Jean Baptiste, the Academician, his brothers-in-law and nephews Sénard, Delafond, David Carré, François Béliard, Jean Arthur, Abraham Bartholony, Amy Dentan, François Dubois, Antoine François, Pierre-Henri Malyvoire, Jean-Philippe Plan, and Daniel-Samuel Platel. His reputation was such that from 1740 until the Revolution, his signature \vas counterfeited. Julien Le Roy and Breguet are without any doubt the clockmakers whose names were most often used by counterfeiters, during their lifetimes and after their death. Julien Le Roy had four sons, who all distinguished themselves in the different careers that they chose. Pierre Le Roy, the eldest, succeeded his father as the King's Clockmaker, and became famous as a naval clockmaker. The second, Jean-Baptiste Le Roy, became a member of the Royal Academy of Science in 1751 as a specialist in mechanics, surveyor, and physicist. His assistance in compiling the Encyclopédie is undoubted, and responsibility for the King's Physics Cabinet \vas conferred upon him in 1774. He worked with his brother Pierre until he was 30, in the family workshop. His knowledge of clockmaking \vas extensive, and his work was important. He was, in particular, the author of a paper rend to the Academy concerning a new arrangement of the wheels in simple watches, known as "fusée renversée". Such a re-arrangement had earlier been discussed by Alexandre in his Traité Général des Irorloges,1734, p. 250. Thomas Hatton, in An introduction to the mechanical part of dock and watch work, 1773, pp. 226- 37 approved of Jean-Baptiste Le Roy's arrangement, but by that time it had become obsolete in France thanks to the production of movements without fusee. Julien-David Le Roy, his third son, vas a wellknown architect, member of the Literary and Architecture Academies. Finally, Charles, the fourth son, was professor of medecine at the University of Montpellier, and a corresponding member of the Academy of Sciences. Among the several sources concerning Julien Le Roy and his family, see : Jean-Dominique Augarde : Les Ouvriers du Temps, Antiquorum Editions, and La Dynastie des Le Roy, Horlogers du Roi, the catalogue of an exhibition at the Musée des Beaux Arts, Tours in 1987 under the scientific direction of Catherine Cardinal and Jean-Claude Sabrier and with contributions by A. Chapiro, J. Le Bot, J. Prieur and A. J. Turner.