"Mr Sully's aim was to produce a machine in which the movement would be as equal and constant, if possible, as a seconds-beating pendulum clock, and which would not suffer the imperfections which pendulum clocks are subject to at sea and in different climates.He reduced these imperfections to three main types, which are:1) Variations, as small as they may be, arising from the expansion and contraction of metals and all bodies, of which heat and cold are the evident causes, not to the exclusion of others.2) Variations of greater magnitude, caused by the inequality of the weight of bodies in various parts of the terrestrial globe, which has not yet been reduced to certain formulae.3) The difficulty, or perhaps the impossibility of suspending a pendulum of a length to measure time with sufficient accuracy, in a vessel on the sea, in such a way that the diverse movements of the vessel would not disturb the characteristic motion of the pendulum".Such were the objectives which Sully sought to obtain in undertaking the construction of his marine clock.Henry Sully (1680-1728), despite his French surname and the fact that he was destined to spend most of his life in France, was English by birth. He was apprenticed in London in 1694 to no less an artist than Charles Gretton and early showed such promise that he came to the notice of various luminaries amongst whom must be mentioned Newton, Sir Christopher Wren and John Flamstead, Astronomer Royal. This pattern was to continue throughout much of his life. In 1705 he became a Freeman of the Worshiful Company of Clockmakers.Sully had an unusually active and inquisitive mind combined with an adventurous nature. Once qualified, he lived in turn in The Hague, in Leiden and in Vienna before settling in Paris in 1714. During two years spent in Leiden, Sully, besides repairing watches in order to live while writing his first book, Règle pour faire un bon usage des montres, published there in 1711, managed to make time to study fully the unperfected work of Huygens in the latter's painstaking endeavours to devise oscillatrs capable of controlling timekeepers at sea. The fulfilment of Huygen's attempts became Sully's dream. It was not however, until he was in his mid-thirties that he was able to give his own idea his full attention. While still in Vienna in 1714, he saw published in the French language, the first edition of his famous and still important treatise, Règle Artificielle du Tems. This work set a new standard and was to influence all French writers on horology of the 18th century. Sully in that same yer moved to Paris where in 1717 he published a second, enlarged edition of his Règle and formed an enduring rapport with Julien Le Roy, then also recently arrived from Tours. The two shared a great many interests and experiments. Julien, many years later in 1737, offered an affectionate and understanding résumé of his friend's life and work in his (Le Roy's) augmented third edition of Sully's Règle. Sully was not long in Paris before attracting the attention of the then Contrôleur Général des Finnces, the powerful Scottish financier, John Law (1671-1729), and through him the patronage and backing of the patriotic and enlightened Régent de France, Philippe, Duc d'Orléans (1674-1723). French horology, especially watchmaking, at that time had reached a peaceful plateau and had ceased to be in any way remarkable or competitive. There were indeed excellent craftsmen, but their watches compared unfavourably with the best London work. France also depended largely upon England for springs and fr steel generally. Law thought that he saw in Sully the means of rectifying the situation. Accordingly, the Englishman was sent home to recruit some sixty workers and in 1718, a watch factory, funded with Government money, was set up in Versailles. This venture was doomed to failure. Sully was sacked and the project was put into the hands of John Reith, one of his assistants. Sully, however retained some staunch supporters, chief of whom was the Maréchal de France, the Duc de Noailles (1678-1766who enabled him to set up a rival watch manufactuary in Saint Germain, between Paris and Versailles. Both watch factories, however, were soon out of business, due largely to general economic difficulties. By late in 1720, Sully and most of the workers had gone home. Despite the failure of the two factories, Sully had made a major contribution to the revival of French horology. The short existence of the two "English" enterprises had somehow shocked Paris makers out of their longstanding indolene and suddenly a general effort was made to compete for wider markets.Upon his arrival in London, Henry Sully received a portion of the subsidy that was promised for his return and above all to entice the watchmakers from the factory at Saint Germain, to return to England. It was with this money that he resumed his study of Huygens' oscillators and undertook research on the escapement utilised in his marine timekeeper and which today carries his name. He showed this escapement to the then Lord Parker, who was at that time Chancellor of Great Britain. Parker gave Slly some financial support. Unfortunately, after the death of this Secretary of State, his successor was less favourably disposed, and Sully never saw even a fraction of the sums which he had been promised. He made the decision to return to France and established himself at Versailles. He took with him his Horloge à levier "A". This he had made and had had going in London in 1721. It was a modèle only, it beat seconds, went for eight days and had his escapement, courbes and levier. It was the fist of the three very different pendules à levier, the cardinal feature of which he described at length in Description abrégée d'une Horloge d'une nouvelle invention pour la juste mesure du Temps sur Mer? 1726. He showed it to the Académie Royale des Sciences in April 1723. It was received with interest and performed well in several tests, including one suspended in a carriage, which were carried out under the auspices of the Académie. In the report of the Académie Royale des Sciences, it was staed: .... it is easy to regulate this machine with a seconds-beating regulator, to two or three seconds in twenty four hours, and during the first trial made at the Observatory, the clock did not vary more than nineteen seconds in eight full days, by a regulator at that place to which it was compared by Monsieur Cassini, for the information of the Académie.Sully thereafter made a number of modifications to "A". These were progressively and none too carefully completed and included the addition of a six-hour train-remontoire, a greatly enlarged going barrel (the mainspring is scratched-dated 1723) and a much revised train affording a duration of going of36 days. Fortunately, these changes are very fully described in Description abrégée .... and for this reason, Sully's pendule à levier "A" has been in the Collection of the Worshipful Company of Clockmakers in London, since 1821.Sully's second sea clock, called by him "B", was made in Paris in 1723, following the great encouragement given to him by the Académiciens after seeing his modèle. "B" embodied a number of new features. Its balance, like that of "A", beat seconds. It went for eight days. It had a fifteen-minute train-remontoire, jewelled pallets, anti-friction wheels to both balance pivots and to the front pivot of the levier arbor. Above all, "B" had a "pirouette" escapement (one in which the pallet arbor carris a wheel driving a pinion on the balance staff - thus affording greatly increased balance amplitude). "B" was the pendule à levier which brought Sully his short-lived fame. It was that shown in plates I and III of Description abrégée...1 and was also the piece described and illustrated by all other writers. "B" seemed at first to offer considerable promise. It was shown to the Académie in January 1724 and was placed in the Paris Observatory under the astronomer Jacques Cassini (1677-1756), wherit was tested both against a standard regulator and also "suspended" in a horse-drawn carriage, driven hard over the steep and rough track leading from the Observatory tower. These trials and inspections were carried out under the control of Messieurs Saurin, Cassini, de Reaumur and de Mairin. Sully recorded all these events in very honest detail in a letter written to George Graham dated 5th November 1725 quoted in full in Description abrégée ... (pp. 92-109) and described how "B", on which hehad pinned all his beliefs and hopes, became gradually erratic in its going and that his best endeavours in the way of adjustments, mainly made to its courbes, produced no worthwhile or permanent improvement. All this led him most unhappily to conclude that its good going was unsustainable due to reduced balance amplitude brought about by gradually increasing escapement friction. This rendered his escapement worse than useless when employed with courbes.2 He said that he feared that it might inhe end be necessary in pendules à levier to use instead the common verge escapement.Some two years before however, news of the early promise of "A" and "B" had spread rapidly, even to London where The Evening Post of 18th-20th June 1723 included a postscript to the effect that "two Pendulum Clocks made by Mr. Sully, an English man, having been tried by Skilful Persons, and found to answer the End proposed, viz, to keep exact time at Sea, notwithstanding the diverse Motions and Tossings of Ships, the Duke of Orleans and many Lords of the Court, have suscrib'd for a good Number othe same, for which they are to pay 500 Livres for each without any Case." Julien Le Roy, in Règle artificielle du Tems3, records that interest was shown also by ambassadors, who wanted examples to send home to their sovereigns, and by a few scientifically-minded men in Paris. Such orders placed Sully in a fix and he had to try to find suitable workmen. But, before anything much could be done, he had, as noted above, come reluctantly to the conclusion that his much prized escapement, if used ina pendule à levier employing courbes, was not only unsuitable, but also a positive disadvantage. He had therefore to decide whether to continue to make use of it and to deliver timekeepers with known imperfections, or, to keep customers waiting even longer and endure their complaints while trying, somewhat desperately, to obtain better results. This was the situation by 5th November 1725. It was not until September 1726 that Sully, having during the previous year made endless small adjustments t"B", at last took it to Bordeaux for a series of tests conducted both on land against a pendule à secondes and on water with "B" mounted in gimbals and placed sometimes in a small boat and finally in a brigantine in the Garonne estuary under conditions varying from flat-calm to exceedingly rough. The overall results were not encouraging.Sully's third pendule à levier, "C", was completed in Paris by the end of 1724 and was described by Sully in a letter to Graham, dated 5th November 1725, quoted in full in Description abrégée.... (pp. 92-109). "C" differed substantially from both "A" and "B". Its balance beat half-seconds. It employed a fusee and Sully was at pains to draw Graham's attention to the fact that the whole piece had been made with great care and that for almost a year it had been in the hands .... d'un homme de condiion, qui est curieux, ingénieux et sçavant dans la Navigation, aussi est il un des premiers Officiers de la Marine de France Sully went on to say that among the other obligations which he owed to this Gentleman, whom he identified as the Chevalier de Luines, was that the latter, while he had the clock, had made a series of very careful and exact observations of its going. Sully quoted these results. They showed that "C", despite replacement oil being put to its pallets and further attention beingiven to its mainspring "set-up" with the aid of an improvised adjusting-rod, would not maintain for more than short periods the necessary balance amplitude of 120°. Sully also, and once more without success, had re-shaped his courbes. He concluded his letter by expressing his disappointment with the going of the piece with these words: Je dois convenir ici que le désordre imprévu qui est arrivé à mes palettes en "C" et dont je viens de parler, ne semblent guère cadrer avec le calcul que j'ai fit à leur avantage dans mon premier Mémoire..... il restera toujours une juste distinction à faire entre ce qui peut être vrai dans la théorie, et l'effet des accidents imprévus qui surviennent souvent dans la pratique. It would, however, have been in character for Sully, in "C", to have removed even his courbes and (final) horsehair line, sooner than abandon his escapementThe two-plane, dead-beat, frictional-rest escapement of which Sully was inordinately proud and which bears his name, was developed by him in the years up to 1721, after his having been deeply impressed by that in the celebrated Debaufre watch, shown to him by Newton in 1704. It is interesting to note that in this pendule à levier Sully's pallet-discs are made so as to be reversible on their arbor, in order to offer a choice of two differing inclinations of impulse planes. These pallets reflectsully's continual experiments and his never-resolved uncertainty how best his escapement should be made. Another part of the same dilemma is apparent from the clearly progressively modified shape of the escape wheel teeth. These have been repeatedly re-cut (no doubt in Sully's famous engine) and now are little more than pins.The plain brass balance, which has had a ring added to it to make it heavier, has no spring. It beats half seconds. Its arbor extends backwards to a cock behind the back movement plate and carries a crank and a connecting-rod reaching downwards to support a horizontal lever (the levier) pivoted at one end and weighted at the other. When the balance is in motion, then the lever is alternately raised and lowered by the connecting rod. This crank-and-rod linkage, which is carefully made, would seemto reflect a late and final attempt made by Sully to improve performance. It is far too intelligently conceived to have emanated from an ordinary workman. Its "Cardon-joints", top and bottom, allow for any misalignments while involving minimal friction.In Sully's published conception, as originally present in this piece, the rear balance pivot carried a matched pair of moving "courbes" (Huygens-inspired "cheeks") from the apex of which a very fine line of silk or horsehair (or eventually even a watch fusee-chain, for Sully, before he had done, tried everything possible) stretched down to join a "cheek" on the lever. Sully believed that this extraordinary gravity-controlled balance, used in conjunction with his escapement, would enable his marie timekeeper to perform at sea in any latitude or temperature as well as a good observatory regulator.The going train employs a fusee (without maintaining power) driven from a large barrel and powerful spring through a strong gut line. Here once more, is found evidence of Sully's open mind and perseverance. The clock was at first given a going barrel, but a fusee was substituted in the early stage of manufacture. We know this because of stopped holes discernible in the movement plates while the original winding hole in the dial centre was filled and matted before it was gilded. The striking-traiis driven by a going barrel.The three pendules à levier, described specifically by Sully in Description abrégée...were, as has been shown, known as "A", "B" and "C"4 . Sully's intimations concerning other examples are not at all convincing, although hinted at on pp. 92, 93, 138, and 276 and mentioned positively by Julien Le Roy in his 1737 edition of Sully's Règle, pp. 402 and 406. The fact is that no shred of evidence now exists to prove that any were in fact delivered."B" seems to have disappeared. It was probably that recorded in 1754 in the Inventory of the collection of late Monsieur Pajot d'Ons-en-Bray: "No. 1571 - Pendule de Gallonde (the name "Gallonde" was crossed out and replaced by that of "Sully"), avec pied de bois, pour la somme de 400 Livres.Julien Le Roy wrote of his friend (Règle, p. 381) that theArts had their Martyrs just as much as the Religions and that Sully was surely amongst them. He added that Sully cared nothing for money, only for perfection. Although "he was most graciously received in this town by members of the Académie de Bordeaux and other persons of distinction" and that after being tried on board on the Garonne, the marine clock was presented to the King who granted a pension to Sully of 600 Livres, which was paid to him regularly, Julien Le Roy describes how Sully, ruind financially by the expenses incurred both in his researches and in Bordeaux, returned at last to Paris to findthat his furniture and his most precious tools had been sold in his absence to meet his debts and how he then fell ill with a broken heart. He died in October 1728 and was buried inSt. Sulpice.As to the implication that Sully may in the end have employed verge escapements in pendules à levier, any direct evidence is once more entirely lacking. On contrary, Description abrégée..., reproduces (p. 143) a letter written to Sully by M. Navarre, dated 20 September 1726, which shows clearly that Sully had by then done no such thing. Navarre urged him to change "B" escapement to a verge (p. 151). Sully's reply (p. 159) of two days later shows him to have remained as stubborn as an old mule. Tere, in all references to pendules à levier he confined himself to reiterating the early promise shown by "A". Yet, as we know, earlier that month, "B" had been tested in the Garonne with disappointing results. Sully continued defensively to correspond with various savants. Description abrégée...ends for all practical purposes, with Sully's Impatience (Longing) in which he continued to maintain that it should be possible to regulate his sea-clock beside a pendule à secondes to less than a minutea month while stating that he had no doubt that ways would be found of doing the same at sea.The newly-discovered clock is a unique document. All the available evidence leads to a conclusion that it is the clock called by Sully "C". It is an important stepping stone in the search for a timekeeper which would enable mariners to ascertain their Longitude position at sea.1 Plate I in Description abrégée shows Sully's oscillator system as used in pendule à levier "B". Plate III illustrate a pendule à levier cased and suspended, as intended by Sully, in gimbals from the deck-head of the chart room of a ship.2 Je me borne ici à dire seulement, que partout où l'on employe les courbes, ces palettes non seulement n'y sont d'aucune avantage, mais qu'elles y sont plutot nuisibles.3 Règle artificielle du Tems, p. 402.4 Je ne m'attacherai qu'aux objets principaux et qui seuls méritent qu'on les examine à fonds. (Description abrégée... p. 93). Sully, in writing of "A", "B" and "C", described only features and changes considered by him to have bearing on their time-keeping properties. He would not have regarded a striking-train, much less a simple calendar, as in any way relevant.Principal Literature:1) By Sully himselfDescription abrégée d'une Horloge d'une nouvelle invention, pour la juste mesure du temps en mer - Avec le jugement de l'Académie Royale des Sciences sur cette invention et une Dissertation sur la nature des tentatives pour la Découverte des Longitudes dans la Navigation, & sur l'usage des Horloges, pour la mesure du Temps en Mer. Paris, janvier 1726.Including:Suite de la Description abrégée d'une Horloge d'une nouvelle invention pour la juste mesure du temps sur Mer.First part printed in Paris, janvier 1726.Second part printed in Bordeaux, décembre 1726.Of particular importance in the above work, are;- First Mémoire of 17 April 1723, addressed to the Académie, when showing them Pendule à Levier "A". p. 49.- Second Mémoire of 8 January 1724, addressed to the Académie, when showing them Pendule à Levier "B". p. 63.- Sully's second, third and fourth letters to Graham, dated respectively 29 August 1724 (p. 78), 21 October 1724(p. 90) and 5 November 1725 (p. 92).- Graham's first and second letters to Sully, dated respectively: 21 July 1724 (p. 74) and 12 October 1724 (p. 87). The earlier of these two letters is a reply to Sully' first letter dated 29 June 1724.Although the pendule à levier "A" is now in the Clockmaker's Company's Museum in London, it cannot, as has been believed and stated, have been sent to Graham by Sully on 29 June 1724. Most careful reading of Graham's correspondence with Sully makes plain that Graham, by the time of his second letter to Sully, on 12 October 1724, had yet to see any pendule à levier. Indeed, Sully's fourth letter to Graham, dated 5 November 1725, records his thwarted intention of sending three pendules à levier toGraham. Presumably they would have been "A", "B" and "C".How "A" came eventually to England is not at present clear.2) By other authors: - Gallon: Recueil des Machines et inventions approuvées par l'Académie Royale des Sciences, tome 4, p. 75, article No. 244, 1724. - Julien Le Roy,: Règle Artificielle du Temps ... par M. Henry Sully..., Nouvelle Edition corrigée et augmentée de quelques Mémoires sur l'Horlogerie, par M. Julien Le Roy, Paris 1737 (particularly pp. 381-409) - Thiout l'Aîné: Traité de l'Horlogerie Méchanique et Pratique, Paris 1741, pp. 103-105, pl. 42. - Ferdinand Berthoud: Histoire de la Mesure du Temps par les Horloges, Paris 1802, chapter XV, article XVII, pp. 285-291, pl. XII, fig. 1, the escapement fig. 2, the suspension pl. V, fig. 7.Henri Enderlin. Eminent horologist, originally from Basel, he settled under the Regency in the Enclos of the abbaye of Saint-Germain-des-Prés in Paris, where it was not necessary to be a Master to be allowed to work; therefore he was never received Master.He is known for having made numerous studies on escapements, clocks with equation of time and was the author of the chapter on "Irregularities of Pendulum" in Thiout's Traité de l'Horlogerie Méchanique et Pratique, Paris 1741, where the majority of his works were also described and commented. The discovery of this Horloge à levier by Sully, carrying the scratched signature under the dial: Enderlin de Bâle, fait en 1724 pour Monsieur de Sully allows one to think that the escapement produced in 176 and which is traditionally attributed to Enderlin, is in fact just a little more than the Sully escapement, improved by the combination, as in the Debauffre escapement, of a single pallet on the balance staff, with a double escape wheel having slanted teeth. Henri Enderlin died in Paris circa 1753.