HERE IT IS!
I am pleased to offer from my private collection this ONE OF A KIND in the world antique 18th Century PROTOTYPE Cylinder Fusee(chain driven) 22k solid gold  SKELETON demonstation case pocket watch&matching chatelaine by one of the most important French watch masters-Ferdinand Berthoud(1727-1807).MUSEUM PRISTINE MINT CONDITION!!!The watch has been made specially for the Ottoman Sultan's Court.Amazing enamel dial with Ottoman numbers and special original solid gold hands. Original high domed crystals on both sides.High grade fire gild  fusee cylinder movement with a hand pierced and engraved skeletonized plates.
Please note,that it is prototype escapement made by Berthoud and no other watch like this is known to be ever produced by the master. 
Note that this is not an ordinary verge fusee movement,but a special fusee CYLINDER movement,which was the next generation movement,which sent the verge movements to the history.The new fusee cylinder escapement gives a better precision compare to the old verge fusee watches!
 
​The watch has a solid 22k coin gold case! 46mm in diameter. 66g heavy.The watch comes with a matching gild chatelaine fob with attaching original solid gold key,solid gold seal fob and a locket fob.PERFECT WORKING ORDER!
PLEASE WATCH THE VIDEO CLIP BELOW;
  If you are not satisfied in 100%,your money back guarantee. Free shipping to worldwide,fully insured(possible byDHL overnight courier) NOTE:PLEASE OBSERVE CAREFULLY THE PHOTOS! IT IS A SIGNIFICANT PART OF THE DESCRIPTION.
Every potencial defect which is shown in the photos,but not mention in the description,will be considered for described.All the photos shoot by professional Nikon 105 Macro lens under 40x diopter magnification,so you can explore even the smallest detail like under microscope!History of Ferdinand Berthoud; Ferdinand Berthoud (18 March 1727, Plancemont-sur-Couvet, Val-de-Travers, Canton of  – 20 June 1807, ) was a French watchmaker and scientist. He was awarded the title of Master Watchmaker in  in 1753. He occupied the position of Horologist-Mechanic by appointment to the King and the Navy and left behind him an exceptionally broad body of work, notably in the field of marine chronometers. He succeeded the pioneering work of . At the king's insistence he travelled to England to view the chronometers of . Together with his great rival, , Berthoud contributed to the development of the chronometer, .He was made a member of the  and elected a  of London in 1764. Among other works he wrote Essai sur l'horlogerie in 1763. Ferdinand Berthoud settled in  on April 16, 1745 at the age of 18, a move that enabled him to perfect his knowledge of the watchmaking-clockmaking profession. He is generally considered to have entered the workshop of . Ferdinand Berthoud rapidly acquired a reputation for technical competence and achieved recognition for his innovations in his field. From 1755 onwards, he was entrusted with writing several reference articles on horology for the “Methodical Encyclopaedia” published between 1751 and 1772 under the supervision of Diderot and d’Alembert. Ferdinand Berthoud published his first specialised book in 1759, entitled L’art de conduire et de régler les pendules et les montres, à l’usage de ceux qui n’ont aucune connaissance d’horlogerie (The art of operating and adjusting clocks and watches for those who have no horological knowledge). This was a popular scientific work that proved a great success and was translated into several languages and then repeatedly re-edited during the 18th and 19th centuries. On December 13, 1760, Ferdinand Berthoud submitted to the  a Mémoire sur les principes de construction d’une Horloge de Marine (Dissertation on the construction principles of a marine chronometer), the famous Marine Chronometer No. 1, whose construction was completed at the start of 1761. He made marine clocks to calculate longitude at sea. In 1764, by order of the King, the Academy charged two of its members,  and Abbot Chappe d’Auteroche with putting the Marine Chronometer No. 3 by Ferdinand Berthoud to trial at sea. They set off from Brest aboard the corvette L’Hirondelle on October 7 that year, accompanied by Ferdinand Berthoud. The mission report, read by Abbot Chappe d’Auteroche to the Academy on November 14, was never published, an exceptional occurrence. In his Traité des horloges marines (Treatise on marine chronometers), Berthoud insinuates that this omission was due to Duhamel du Monceau whose nephew, Fougeroux de Grandlieu, having served as lieutenant during this expedition, died several days after the ship’s return. Ferdinand Berthoud was appointed Horloger du roi (Horologist-Mechanic by appointment to the King and the Navy) in 1770. He was also named a member of the Institute right from the time of its creation in 1795. Berthoud had meanwhile become a member of the  on February 16, 1764. He is regarded as one of the inventors of the marine chronometer that served to determine longitude at sea necessary to navigation. His nephew Louis Berthoud, also distinguished himself as a horologist. Ferdinand Berthoud married Henriette Chatry de La Fosse, and later Marie Adélaïde Dumoustier. He died in 1807 at his home in Groslay near , . He had married twice, firstly Mademoiselle Chati of Cean, and then Mademoiselle Dumoustier of Saint Quentin, but had no children. His business passed to his nephew, Louis Berthoud (1759–1813). Obliged to work as a companion-horologist with masters of the Parisian corporation, having failed to serve his apprenticeship under one of them, the young Berthoud managed to overcome this hurdle by drawing attention due to “his application in perfecting the art of watchmaking.” He seized the possibility of making his research known at the Royal Academy of Science by submitting a sealed document describing a new construction. The approval, granted by academy members on April 26, 1752, of an equation clock that was deemed highly ingenious, marked the start of his career as a researcher, while also enabling him to lay claim to official integration into the horological community. On December 4, 1753, the King of France ordered that he should be granted the title of master, authorising him to open a workshop on the Rue de Harlay, near the Place Dauphine. In 1754, the master horologist once again submitted his inventions to the Academy. One was his first marine chronometer project. The others, examined and approved by academy members, were also equation systems: “a concentric seconds equation marking the months and days of the month, leap years, and running for 13 months without requiring rewinding”; a seconds and equation watch marking the month and days. Before even being named a Master Watchmaker, Ferdinand Berthoud revealed the meaning he wished to give to his career: devoting himself to research and passing on his knowledge through publications and teaching. This two-fold commitment enabled him to swiftly establish himself in the scientific circles of his era. Several articles of the Encyclopaedia supervised by  were entrusted to him, particularly the “Equation” article. In 1759, he published a popular work that would prove a success: L’Art de conduire et de régler les pendules et les montres. A l’usage de ceux qui n’ont aucune connaissance d’horlogerie (The art of operating and adjusting clocks and watches for those who have no horological knowledge). In 1763, his voluminous treatise, L’Essai sur l’horlogerie ; dans lequel on traite de cet Art relativement à l’usage civil, à l’Astronomie et à la Navigation (Essay on Horology, dealing with this Art relating to civilian use, astronomy and navigation) was also favourably received. The year 1763 marked a turning point in Berthoud’s career, which was now closely linked with the progress of maritime navigation. The Academy of Science was once again both a witness and a support in this realm: the horologist had two sealed documents describing Marine Chronometer no. 1 delivered to it in 1760 and 1761. Convinced by the watchmaker’s competence, the academy members persuaded the French Navy Ministry to send Berthoud to examine Harrison’s marine chronometer. This turned out to be an opportunity for him to be appreciated by his peers and appointed as a foreign associate of the Royal Society on February 17, 1764. On August 29 that same year, Ferdinand Berthoud once again submitted a document relating to the “construction of a marine clock…”. It was to be the last: Berthoud was by then certain to have found the path of his research and to have the possibility of requesting official backing. The cadence for his activities was set by projects relating to detailed requests. He proposed the construction of two marine clocks on May 7, 1766: these were Nos 6 and 8 exhibited at the  After successful experimentation with these clocks, Ferdinand Berthoud was awarded the title “Brevet d’horloger Méchanicien du Roi et de la Marine ayant l’inspection de la construction des Horloges marines” (warrant of Horologist-Mechanic by appointment to the King and the Navy responsible for the construction of marine clocks), specifically created for him on April 1, 1770. From that point onward, he set aside the management of his workshop-boutique to dedicate himself to research, stating in 1792: “it was above all from 1770 onwards that I devoted myself wholeheartedly to this aspect and in some ways departed from my public work." A tenacious experimenter, a clever and daring builder and an inventor keen to share his knowledge, Ferdinand Berthoud not only played a part in the advancement of watchmaking, but also fostered the use of precision clocks in the scientific endeavours of his era, thereby contributing to their progress. The titles, privileges and testimonies of recognition punctuating his career, between the reign of  and the First Empire, followed by the tributes and the studies devoted by critics to his work right the way through to the present day reflect the importance of his place in the longstanding quest for precision since Huyghens’ discoveries through to those of Guillaume.