The Longitude at the Eve of the Third...

Geneva, Hotel Des Bergues, Oct 23, 1999

LOT 5

French, circa 1770.Important and extremely rare watch with Sully frictional rest escapement, constructed on the principle of the watch elaborated in 1715 by Julien Le Roy and Henry Sully, constructed by Julien Le Roy and presented by Sully to the Académie des Sciences on June 10, 1716.

CHF 13,000 - 15,000

Sold: CHF 11,500

C. Silver gilt Louis XV with glazed back. D. Slightly later white enamel with radial Arabic numerals and outer minute ring. Later blued steel hands. M. Hinged gilt brass, fixed barrel with revolving arbor, three wheel train used in conjunction with a form of Sully's frictional rest escapement with double pallet and single escape wheel, so arranged that the balance staff is kept horizontal in both "hanging" and "lying" positions. Plain brass three-arm balance, flat balance spring.Diam. 47 mm.


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Grading System
Grade: AAA

Excellent

Case: 29

Lacking elements

Movement: * 4 - 5
Dial: 29 - 12 - 04

Notes

To understand the purpose of such unusual arrangement for a watch movement, it is important to read in either the second or the third edition of Sully's Règle Artificielle du Temps, his Description d'une montre d'une nouvelle invention, written in 1716, where the calibre is illustrated Fig. 15, and his Histoire critique de différentes sortes d'échappement, probably written between 1726 and 1728, and included by Julien Le Roy in the third edition of Règle Artificielle du Temps, posthumously publihed in 1737. Sully discusses the variation in timekeeping of an ordinary verge watch, according to whether it is hanging or lying. He mentions several causes, such as lack of balance poise and the differing amplitude of the balance depending upon whether the verge pivots are running on their sides or on their ends.For more information, please refer to the article by Charles Allix, Sully, Verlinden and others...., Antiquarian Horology, Winter 1980. (A copy of the article will be supplied to the buyer.)This watch embodies, the features of Description d'une montre de nouvelle construction in conjunction with the frictional rest escapement as it was divised by Sully.In the section added to the third edition of Règle Artificielle du Temps, posthumously published in 1737, Julien Le Roy relates the circumstances of the construction of the watch mentioned above.When Sully arrived in Paris in 1715, with the Duke of Arenberg, his protector, he was living in the Hôtel d'Ansbac opposite rue Saint Benoît, not far from Julien Le Roy who was soon introduced to him by Blakey, the celebrated spring maker. Sully and Julien Le Roy became close friends, meeting each other almost every day. During the long discussions they had on watchmaking, they decided to set out a new calibre for watches with several improvements, mainly to reduce the frictions and maintain theoil at the pivots. Unfortunately, before the movement was completed by Julien Le Roy, Sully had to move in order to follow the Duke of Arenberg in his new mansion near the Cloître de Saint Germain, where he met a young lady and fell in love. He therefore forgot to visit his friend and the watch they were designing together. He came only to fetch it a few months later and did not even invite his friend to his wedding. Moreover he presented the watch to the Academy and took advantage of the honourto apply his candidacy to the clockmaker's company of Paris.Règle Artificielle du temps, 1737, p. 238 e Thomas Mudge, (1715-1794) was an apprentice of George Graham and may be considered as his spiritual successor. For the King of Spain he constructed an hour striking watch with minute repeating and an equation of time display. He was one of the first makers to produce constant force watches. His ordinary watches with cylinder escapements are generally speaking constructed on the same lines as those of Graham. In 1755 he went into partnership with Willim Dutton another of Graham's pupils. In the 1760's he developed the free lever escapement. With Larcum Kendall he was nominated in 1765 to examine Harrison's marine watch. In 1770, with a great deal of difficulty he succeeded in making the first lever escapement for watches. The watch was purchased by George III and is still in the Royal Collections. In 1771 he retired to Plymouth where he devoted himself entirely to researches on marine chronometers. It is there that he developed his constant frce marine watch described by his son in a publication of 1799. He was also the inventor of a free escapement with remontoire, of which the principle was published in the Philosophical Transactions of 1794.The Lever EscapementThe escapement was invented in the late 1750's by Thomas Mudge, who used it in at least two clocks and two or three watches. Count von Bruhl, envoy at the English Court from the kingdom of Saxony, and Mudge's patron and friend, asked him to make a model of the lever escapement, in order to publicise it and to establish Mudge as the inventor. Von Bruhl, who was clearly aware of its potential, managed to persuade Josiah Emery to make a series of watches employing the escapement and was one of theirst to own one. Mudge had left London for Plymouth in 1771 and was almost totally preoccupied with the construction of his marine timekeepers, so it was increasingly unlikely that he would use the escapement again himself.From 1781 until 1795, Emery is thought to have made about thirty-six watches with lever escapement, excluding the experimental one now offered for sale, the earliest known isNo. 806, made circa 1780, the last one, No. 1379, in 1795.It is now established that the lever escapement was introduced to France via one of Emery's lever watches. According to Ferdinand Berthoud, Monsieur le Président Sarron had one sent over from London towards the middle of 1782. A model of the escapement was also obtained and is now in the Musée National des Techniques (C.N.A.M.) in Paris. At least, M. le Marquis de Chabert and M. de Puiségure also, each had one of these watches which were copied by Robert Robin in about 1784 and also inspired Lous Berthoud for his very first pocket chronometers.Josiah Emery, (c1725-1797) Swiss watchmaker set up in England at 33 Cockspur Street, Charing Cross, London. Honorary member of the Clockmakers Company in 1781 he made very fine cylinder watches, but became famous as the first watchmaker in the world after Thomas Mudge to produce a watch with a lever escapement. He made about thirty six lever watches between 1782 and 1795. He also used the pivoted detent escapement for precision watches. Louis Recordon succeeded him in 1797. Three of Emery's levewatches were imported into France and served as a model for Robert Robin for a series of precision watches that he produced at the end of the eighteenth century. One of these watches was shown to Louis Berthoud who used the escapement several times, attempted to improve it but finally abandoned it in favour of the pivoted detent escapement.Jean-Maurice Bruhl, Comte de (1736-1809) diplomat and counselor of the Elector of Saxony was ambassador at Paris in 1764 and was sent to London. Author of A Short explanation of the proper methods of calculating a mean Rate, London, 1794, his interest in horology led him to frequent the best London clockmakers and particularly John Harrison. On his return from London Ferdinand Berthoud wrote to the Minister of the Marine 14 March 1766 that 'I cannot sufficiently praise the care and good officesf M. le Comte de Bruhl during my stay in London. It is thanks to him that I attained an exact understanding of the principles and construction ofMr. Harrison's marine watch. Friend and patron of Thomas Mudge, it is thanks to him that Emery's lever watches became known in France.