Important Collectors' Wristwatches, P...

Hong Kong, Jul 10, 2005

LOT 14

?Deck Chronometer? Paul Ditisheim, La Chaux-de-Fonds, No. 703400, Made circa 1915. Extremely fine, silver, keyless deck and pocket chronometer watch with 52-hour power reserve and 1st Class Guillaume balance.

HKD 40,000 - 60,000

EUR 4,500 - 6,000 / USD 5,500 - 7,500

Sold: HKD 49,450

C. Three-body, massive 'bassine et filets carrure plate', polished, flutedband, the backstamped with maker?s trademark, silver detachable cuvette. D. Matte silverwith radialRoman numerals and outer minute track, 52-hour power reserve dial, largesubsidiary seconds dial. Blued-steel 'spade' hands. M. 24???,matte gilt, 21 jewels, straight-line lever escapement, anibal-brassGuillaume balance with gold temperature screws, adjusted to nine positionsand isochronism, blued steel Breguet balance spring, going train jeweled tothe center with endstones on the entire escapement,index regulator.Dial and movement signed, case stamped with Ditisheim?s trademark.Diam. 65 mm.


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Grading System
Grade: AAA

Excellent

Case: 3 - 6
Movement: 3 - 6*
Dial: 3 - 5 - 01

Notes

The movement is inscribed: 'Paul Ditisheim La Chaux-de-Fonds, The highest Records at Kew, Teddington and Swiss Observatories'. The inscription refers to the 200-some prizes Ditisheim won at Kew and in Neuchatel. A very similar watch (No. 46874) brought him first prizes in Neuchatel in 1918 and in 1920, this watch was sold by Antiquorum, Geneva, 15/10/00, Lot 173. Another practically identical watch - the serial number 46877 - brought him a prize at Kew in 1919 for the best in temperature compensation, and another (46871) won him 1st prize in 1917. Timing Contest : Mean average daily rate +/- 0,11 Error of compensation +/- 0,08 Mean error of positions +/- 0,47 Thermal coefficient - 0,003. Anibal (acier au nickel pour balanciers) An alloy invented by Dr. Charles Edouard Guillaume which exhibits unusual properties, both in terms of thermal expansion and changes in elasticity. Its properties are very different from those of two other alloys invented by Guillaume, Invar and Elinvar. At the end of the 1800s, Guillaume attempted to eliminate the so-called Middle Temperature Error, which is caused by the fact that the change of rate in a timekeeper with a steel-brass bimetallic balance is approximately a linear function of temperature, while the modifications caused by the change in elasticity of a balance spring is approximately a quadratic function. Thus, it equals zero at only two temperatures, causing secondary error. Countless attempts were made to eliminate it, usually by adjoining auxiliary compensation devices. In 1899, Guillaume noticed that steel with an addition of 44.4% nickel has a negative square coefficient of thermal expansion. This, combined with brass in bimetallic lamina, makes its expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume balances, or, as their inventor called them, integral balances. Combined with special balance springs, they show amazing temperature stability, sometimes not exceeding 1/50 second per day per 1oC.