Important Modern and Vintage Timepieces

Geneva, Mar 11, 2012

LOT 52

CLIFFORD MAGNETIC ESCAPEMENT Hamilton, ?Railway Special?, No. C390218. Made in the 1940s, this is one of only two known examples to be fitted with a prototype Clifford magnetic escapement, by Horstmann Clifford Magnetics Ltd., of Bath, England, circa 1950. Fine and exceptionally rare, keyless, 10K goldfilled pocket watch with patent Montgomery dial and special escapement, with the original Hamilton box and guarantee. Accompanied by a box and certificate. To be sold without reserve

CHF 20,000 - 40,000

USD 22,000 - 45,000 / EUR 17,000 - 33,000

C. Three-body, ?bassine et fi lets?, screwed-down back, bezel with reeded and dot decoration, large bow. D. White enamel ?Montgomery?, with large Arabic numerals, outer minute divisions, and individual Arabic minute numerals, subsidiary seconds. Blued steel spade hands. M. 18???, rhodium-plated, fausses cotes decoration, now fi tted with a Clifford magnetic escapement with a ?Mumetal? pierced escape wheel and spring-blade detent-type resonator. Dial, case and movement signed. Diam. 51 mm.


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Grading System
Grade: AA

Very good
Case: 3

Good
Movement: 3**

Good

Repair required, at buyer's expense
Dial: 4-8-01

Fair

Slightly scratched

HANDS Original

Notes

Due to its experimental nature and delicacy, the timekeeping of this watch can be intermittent, with a duration of approximately 10 hours. This fascinating watch is one of only two known Hamilton watches that were sent by The Hamilton Watch Company to Horstmann Clifford Magnetics Ltd in Bath, England, for modifi cation. The Clifford Magnetic Escapement Invented by Cecil F. Clifford, BSC, FBHI, in 1938, it was experimented upon during World War II with the aim of producing a silent time bomb for naval use. The theory was that as the escapement does not ?tick? it would be undetected by sonar. The escapement consists of a fl at pierced sinusoidal escape-wheel made of a magnetisable material called ?Mumetal? mounted horizontally, and a fl at upright ?detent? terminating in two prongs allowing the escape wheel teeth to pass through. After the war, Clifford approached various fi rms with the idea of using the silent escapement in clocks and watches. He eventually joined the company of Horstmann Gear Ltd, a maker of mechanical clocks. In 1948 the company became Horstmann Clifford Magnetics Ltd, producing clocks and watches with magnetic escapements. The company never actually went into production with magnetic escapements but instead approached various companies to take out production licenses. The Hamilton Watch Company was approached and sent two watches over to England for the escapement to be fi tted, the present watch is one of these pieces. Although it was reported that the watches performed well, Hamilton did not take out a manufacturing license and in fact neither did any other company. HCM achieved great success after 1952 with electronic clocks and watches with ?tuning fork? mechanisms and in fact all tuning fork clocks made in the 1960s had magnetic escapements similar to the Hamilton prototype that were linked to an electronically operated transistorized mechanism. With the advent of quartz technology, the escapement became obsolete by 1970. Montgomery Dial Designed by H.S. Montgomery and patented on April 20, 1920. This dial is distinctive in that every minute marker has an Arabic numeral written in full. See: Antiquorum, New York, The Art of American Horology, Part II, December 5, 2002, p. 139.