The 'C' couronné poinçon was a tax mark employed on any alloy containing copper between March 1745 and February 1749.
Pierre II Le Roy was son of the master clockmaker of Tours, Pierre Julien le Roy, and was trained by his father before establishing his own workshop in Paris and receiving his maîtrise in 1721. Though his brother, Julien le Roy (1686-1759), was perhaps more famous as a clockmaker, Pierre is known to have been a member of the Société des Sciences and his clocks were set in cases supplied by Paris' leading fondeurs and bronziers such as Jacques and Philippe Caffieri, Charles Cressent and J.J. de Saint-Germain. His clients included the Garde Meuble de la Couronne, the duchesse d'Halincourt, and the duchesse du Maine, among others.
This clock movement could equally have been made by Pierre III Le Roy. The son of clockmaker Julien II Le Roy and nephew to the aforementioned Pierre II Le Roy, Pierre III succeeded his father in 1759 as the Horloger Ordinaire du Roi, in residence in the Louvre.
An enameller and miniaturist, Antoine Nicolas Martinière (1706-84) was named a pensionnaire du Roi in 1746 and is known to have established a workshop on the rue des Cinq-Diamants by 1741. Two signed works demonstrate his considerable talent. The first is an enamel now at Versailles, The Battle of Fontenoy, which is signed and dated 1747. The second is a signed, enamelled perpetual wall-calendar made for Louis XV in 1741-1742 and now in the Wallace Collection (F.J.B. Watson, Wallace Collection Catalogues: Furniture, London, 1956, pp. 34-35, plate 1). He was the first to perfect a technique for making an enamel dial from a simple piece circa 1730/40 for which he was awarded a pension by Louis XV.
Further clocks of this model include one in the Musée des Arts Décoratifs, Paris (illustrated in A. Gruber, L'Art Décoratif en Europe Classique et Baroque, Paris, 1992, p. 308); another with movement by Gosselin illustrated in P. Kjellberg, Encyclopédie de la Pendule Française, Paris, 1997, p. 107; another illustrated in H. Ottomeyer and P. Pröschel, et al, Vergoldete Bronzen, Munich 1986, vol. 1, p. 118; and two examples sold at Christies, one sold Monaco, 13 December 1998, lot 336, and another sold from the Wildenstein Collection, 15 December 2005, lot 111.