L\'ART DE L\'HORLOGERIE EN FRANCE DE ...
Geneva, Hotel Des Bergues, Nov 14, 1993
Ferdinand Berthoud, à Paris, No. 310, bearing the Paris hallmarks for 1758-1759. Extremely fine and unique, 20 ct. gold and enamel, dumb quarter-repeating, Montre à secondes qui va huit jours sans remonter, dont le régulateur est formé par deux balanciers qui font un battement à chaque seconde, constructed on the principle, described in Ferdinand Berthoud: Essai sur l'Horlogerie, published in 1786, pages 216 to 221, plate No. XXVII, fig. 6-7-8-9 and 10, the enamel painted by Hamelin.
C. Double body, Louis XV, the bezels with enamelled floral decoration, the back with a finely painted urn of flowers signed Hamelin, (slightly restored). D. White enamel with Roman numerals, outer Arabic minute ring and subsidiary seconds. Gold Louis XV hands. M. Hinged gilt brass full plate with cylindrical pillars, fusee with chain, large brass wheel cylinder escapement with two plain polished steel balances geared together, single flat balance spring, large single gilt brass continental cock with a polished steel end-piece for each balance. Repeating on the case with a single polished steel hammer, the complete repeating mechanism (repeating work and wheel train), set between the dial and the front plate. Signed on the dial and back plate. In very good condition. Diam. 48 mm.