Exceptional Horological Sale Celebrat...

Hotel Noga Hilton, Geneva, Apr 24, 2004

LOT 39

Abraham-Louis Breguet An exceptional and extremely important collection of 9 workshop notebooks, comprising 110 pages of Abraham Louis Breguet's daily journal, in his own hand, which record crucial points of his work from 13 Frimaire an 7 (December 3, 1798) to April 13, 1803 (two undated notebooks). They include notes on his work, memoranda, preparatory sketches for dials and layout of watches, rough drafts of letters, jottings, notes, reminders of things to be done, and meditations, as well as pencil and ink sketches. First notebook Notes on the classification of watches, expenses ("sphère janvier 200"), ideas for improving production ("faire monter deux cages d'échap[emen]t p[ou]r les montres de Souscription & pour les rép[étition]s de telle sorte que l'ouvrier ne puisse faire son balancier ny plus épais, ny plus grand ?"), pages of calculations and sketches, including gears, escapements and dials. Second notebook Calculations, sketches and instructions for the making of tourbillons, including the draft of a request for the "priv-ilège" for this invention. Third notebook Drawings and specifications for the compensation balance, notes on the constant force escapement applied to the tourbillon regulator. Fourth notebook Notes on the adjustment of watches, including those of such well-known figures as Bonaparte, Praslin, Talon, Rzewuski, and Zolinger, as well as sketches of dials. Fifth notebook Sketches of the Robin escapement, calibers and layout of watches, notes on watch crystals, calculations for gears and notes on à tact and souscription watches. Sixth notebook Notes on a watch for M. le duc de l?Infantado, notes on watch characteristics; description of Emery?s No. 1055, a watch with ruby cylinder escapement; sketches and considerations on calibers and compensation balance. Seventh notebook Notes on how to execute a balance-staff, a chronometer balance-spring, thoughts on chronometer escapements; watch descriptions: Haswall à Londres, Arnold No. 127; metronomic tempi determined by the composer Paisello; philosophical reflexions. Eighth notebook Sketches and calculations for various watches, description of Berthoud?s marine clock No. 2471. Ninth notebook A rough draft of a letter to Alexander von Humbolt; calculations and trials for tourbillon watches (2514, 2436, 2396); various other calculations. All preserved in a brown linen-covered box. Small in-4o. Dimensions 206 mm x 256 mm. Estimate:* * *