This is an exceptional example of the finest work of France's best watchmakers at the turn of the 18th and 19th centuries, both technologically and aesthetically. The case, which is an outstanding example of the casemaker?s art, was crafted by Jean Sanguinede, 39 rue St-Louis, then 18 Quai des Orfèvres, Paris, one of the finest artisans working in France at the time. Early in his career he was the main casemaker for Louis Berthoud, as well as other great French watchmakers such as Jean-Hilaire Bassereau. His work was highly regarded and very expensive. The workbooks of Louis Berthoud show that his cases normally accounted for around a third of the total production cost and on some occasions as much as 50%. Technologically this watch is at the forefront of the watchmaker?s art. The combination of Breguet type caliber, jewelling, parachute on both pivots, compensation curb and detent escapement, is the mark of an exceptional watchmaker with an understanding of the best techniques in precision watchmaking at the time. Jewelling of movements had only been done in France for roughly 10 years at the time this watch was made and then only in the best Parisian workshops, as it was too costly for lesser makers. The parachute, first used by Breguet in 1790, was also a relatively new invention and was reserved for the finest watches. The compensation curb, invented in England by John Harrison in the third quarter of the 18th century, was little known on French watches until the end of the century. The Berthoud detent, invented in the 1780s, was a difficult to make and required a high level of skill, it is one of the more uncommon escapements to appear at auction, in fact only three other watches and one clock with this type of escapement have been sold by Antiquorum in the last five years and all were from the Berthoud workshop. The fact that the watch embodies the best practice of the Breguet and Berthoud workshops suggests that its maker may have worked and/or studied in one or both of these ateliers. The layout of the caliber, along with parachute, compensation curb and jewelling, are all signature traits of the Breguet workshops, and the construction of the detent and choice of case maker directly link the maker to the workshop of Louis Berthoud. It is unfortunate that the maker of this watch chose not to sign the piece, as the present watch places him amongst the greats of French horology. It was customary at the time for pieces destined for high ranking officials to remain unsigned, and this is likely the reason the watch is unsigned. This would also explain the plain outer case, as the watch dates from the Republican period in France, during which any outward display of wealth was frowned upon.