11,500 CHF
Bahne Bonniksen, made for David Keys, Watch and Chronometer Maker to the Admiralty, 91 Piccadilly, London, No. 6161, with Chester hallmarks for 1901.Fine 18K gold keyless watch with Bonniksen patented Karrusel regulator. Three-body, "bassine et filets", polished, monogrammed back, gold hinged cuvette. White enamel by Willis, radial Roman numerals and sunk subsidiary seconds. Blued steel "spade" hands. Notes Bahne Bonniksen, a Dane living in London, invented and patented the Karrusel in 1895 as an alternative to the tourbillon. Both are types of revolving escapement, but the Karrusel is less apt to get damaged if worked on by an unskilled watchmaker. Bonniksen calculated the train as for a classical watch. For a regular watch the beat would be 18,000 beats per hour. However, since the carriage rotates around the 4th wheel (planetary or epicyclic gearing) 8/7 times per hour, that is 8/420 times perinute, the number of beats will be smaller for this amount. So if the 4th wheel has 70 teeth, the actual number of teeth engaging the escape wheel in one minute is 70 (1-8/420). If the escape wheel has 15 teeth and its pinion 7 leaves, the watch beats [70(1-8/420)x15x2x60]/7 =17,657 and 1/7 times per hour (assuming that the center wheel has 80 teeth and the carriage wheel has 70 teeth). This train was designed by Bonniksen and used by many others.It seems that from the very beginning there was speculation as to why Bonniksen did it this way. Some suggested that he did not ta Read more…
Auctioneer:
Antiquorum
Date:
2003-04-12
