75,000 HKD
Bahne Bonniksen Karrusel with Guillaume Balance Bahne Bonniksen, No. 9/1112, retailed by J. Henry Hobbins, Manchester. The case with London hallmarks for 1911 - 1912. Very fine and extremely rare, 18K yellow gold, keyless pocket watch with Bonniksen patented 52 1/2 minute Karrusel regulator and Guillaume balance. Four-body, "bassine", polished, mastermark (FT). Hinged gold cuvette. White enamel, radial Roman numerals, outer minute track, subsidiary seconds. Blued steel poire hands. Notes English watches with Guillaume balances are very rare. Dent and Frodsham used few, Northern Goldsmiths’ Co., Newcastleon- Tyne made a few in 1918, Dreyfuss Moise of London two in 1929. Samuel Smith and Stauffer Co. seem to be the two English companies that had most faith in the Guillaume balance. The Guillaume Balance. Anibal acier au nickel pour balanciers, an alloy invented by Dr. Charles Edouard Guillaume, exhibits unusual properties, both in terms of thermal expansion and in changes in elasticity. Around 1900 Guillaume attempted to eliminate the so-called Middle Temperature Error caused by the fact that the change of rate in a timekeeper with a steel-brass bimetallic balance is approximately a linear func-tion of temperature, while the change of rate caused by change in elasticity of a balance spring is approximately a quadratic function. Thus, it equals zero at only two temperatures, causing secondary error. In 1899, Guillaume noted that steel with an addition of 44.4% nickel ha
Auctioneer:
Antiquorum
Date:
2010-10-09
