L\'ART DE L\'HORLOGERIE EN FRANCE DE ...

Geneva, Hotel Des Bergues, Nov 14, 1993

LOT 83

Ferdinand Berthoud No. 144, Invenit et Fecit 1753. Unique 18 ct. gold "Montre à Equation à Secondes concentriques, marquant les mois et leurs quantièmes", described in Essai sur l'horlogerie, chap. XIV, pp. 77-79, pl. XI.

CHF 180,000 - 220,000

Sold: CHF 358,250

C. Double body, Louis XV, chased with radiant sun-beams and further rocaille decoration, the back with a date aperture and a winding aperture with a shutter linked to a click-work in such a way that the date advances automatically each time the winding shutter is opened, by means of a small boit, to insert the key. Gilt brass protecting case latterly covered with green lizard skin. D. White enamel with Roman numerals and outer Arabic minute ring (hair lines), central revolving equation disc and aperture between "I" and "II" for the annual calendar. Gold Louis XV hands, the equation end of the minute hand set with a rosediamond set sun. Blued-steel counterpoised centre-seconds hand. M. Hinged, gilt brass full plate with baluster pillars, cylinder escapement, plain brass three-arm balance, flat balance spring, gilt brass continental cock with garnet end-stone. Signed on the dial, back plate and dial-plate. In very good condition. Diam. 45 mm.


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Notes

Presented in 1754 to the Académie Royale des Sciences , Paris and to the Royal Society in London, this watch is also described in l'Histoire de la Mesure du Temps par les Horloges, and in Diderot et d'Alembert: La Grande Encyclopédie. In the forward to his Essai sur l'Horlogerie, Ferdinand Berthoud acknowledges that this is not the very first equation watch to be made: La première invention de cette sorte d'équation appartient n M. Le Bon; je l'ai reconstruite à ma ', lanière avec un mécanismne fort simple. The watch is wound through the back of the case, and Berthoud has incorporated a semi-automatic calendar mechanism similar to that described by Thiout, in his Traité d'Horlogerie, Tome II, p. 387. Photocopies of the relevant pages from the different publications cited above will be furnished to the buyer of this lot. Clearly a sensation in its day, as evinced by the fact that it was presented to both the French and English Royal Academies, this watch has been known to subsequent generations through the writings and designs published by Ferdinand Berthoud. However, the whereabouts of the watch itself had been unkno\vn, until it resurfaced only recently. It represents a unique piece from the history of French horology.