French 20k gold and diamond set verge watch Circa 1765

With double virgule escapement to the design of Jean Romilly
–
A very fine, extremely rare French 20 carat vari-coloured gold and diamond set pocket watch with double virgule escapement to the design of Jean Romilly, circa 1765. Frosted gilt full plate movement, pentagonal baluster pillars, fusee and chain, double virgule escapement, three armed brass balance, flat balance spring, pierced and chased continental balance cock, silver regulation dial. White enamel with Roman numerals, outer minute divisions and original rose cut diamond set fleur-de-lys hands. Louis XV case, by Xavier Gide (mastermark XG), bezel and border decorated with laurel swags, the back with a musical trophy within a ribbon border, thumb pieces, pendant and bow set with large rose cut diamonds. Movement signed, case with Paris poincon for 1765.
–
Diameter: 43 mm
–
Signed: Antoine François à Paris
–
Double Virgule Escapement. The double virgule escapement was the subject of one of the biggest horological scandals of 18th century France. In 1753, horloger du Roi, Jean-André Le Paute published a description of a new escapement for watches derived from the pin wheel escapement which had been used with great success in clocks. The new escapement, the details of which were given in Le Paute’s book, was called the ‘double virgule’ escapement. However, the 21 year old Pierre-Augustin Caron, son of another horloger du Roi, André-Charles Caron, wrote in an open letter to the Mercure de France that in July 1753 he had shown Le Paute the escapement, of his own invention, and that Le Paute had copied it and claimed it for his own. The affair caused such a stir that the matter was referred to the Academie Royale des Sciences and on March 4, 1754 they ruled in favor of Caron as the inventor. In December 1754, watchmaker Jean Romilly presented another version of the double virgule to the Academy, which that institution decided had been invented independently of Caron. Therefore both watchmakers were credited with its invention. Although the double virgule produced good results it was very rarely used, probably because of the difficulty of making it and its extreme fragility. The present watch has the version of the double virgule as invented by Romilly. Today watches with this escapement are extremely rare.