Important Collectors’ Wristwatches, P...

Geneva, Mandarin Oriental Hotel Du Rhône, May 13, 2007

LOT 614

?Karrusel ? ?Class A? Kew Certificate, Especially Good? D. & J. Wellby, Garrick Street, London W.C., No. 25562, movement by Bahne Bonniksen. The case with London hallmarks for 1898. Very fine, 18K gold, keyless pocket chronometer with Bonniksen patented Karrusel regulator, obtained ?class A? certificate, Kew Observatory ?Especially Good?, with a score of 85.3 points.

CHF 7,000 - 9,000

EUR 4,500 - 5,500 / USD 5,700 - 7,500

Sold: CHF 10,030

C. Four-body, ?pommes?, solid, polished, master mark ?AF?, thiefproof swivel bow. Hinged gold cuvette. D. White enamel, Willis type, radial Roman numerals, outer minute divisions, subsidiary seconds. Gold ?spade? hands. M. 43 mm. (19 1/2???), frosted gilt, three-quarter plate, 17 jewels, lateral lever escapement, cut bimetallic compensation balance with gold screws, blued steel Breguet balance spring, index regulator, all mounted on a Bonniksen?s mark on Bonniksen 52 1/2 minute Karrusel regulator. Dial numbered, movement signed by the retailer and punched with Bonniksen?s mark on the pillar plate. Diam. 54 mm.


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Grading System
Grade: AAA

Excellent
Case: 3

Good
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-01

Good

HANDS Original

Notes

Bonniksen patent Karrusels enjoyed particular success in the Kew Observatory trials.

Kew Observatory trials for watches
Various testing laboratories around the world were responsible for grading and testing watches. The most stringent being the Kew (Teddington) Observatory, just west of London. A standard Swiss chronometer test would last 15 days, however, the Kew test lasted 44 days. The tests consisted of observing the time keeping of the watch in various positions and at various temperatures and awarding points for accuracy in these differing states. 85.3 marks is not a recordbreaking figure but is regarded as especially good (scores of over 90 were regularly obtained by 1900) and still does the makers great credit. The eight testing positions were as follows: Pendant up - 67° Dial up - 42° Pendant right - 67° Dial up - 67° Pendant left - 67° Dial up - 92° Pendant up - 67° Dial down - 67°