358,250 CHF
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. 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. 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. 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. 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 acknowledg
Auctioneer:
Antiquorum
Date:
1993-11-14
