Important Collectors Wristwatches, P...
Geneva, Hotel Du Rhone, Apr 02, 2006
LOT 401
?Clifford Magnetic Escapement? Hamilton, ?Railway Special?, No. C390218. Made in the 1940s and one of only two known examples to be fitted with a prototype Clifford magnetic escapement, by the firm of Horstmann Clifford Magnetics Ltd., of Bath, England, circa 1950. Fine and exceptionally rare, keyless, 10K gold-filled pocket watch with patent Montgomery dial and special escapement, with the original Hamilton box and guarantee. Accompanied by a box and certificate.
CHF 35,000 - 40,000
108 22,000 - 26,000
Sold: CHF 82,600
C. Three-body, ?bassine et filets?, screwed-down back and 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-côtes? decoration, now fitted 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.
| Grading System | |
|---|---|
Grade: |
|
Case: 3 |
Good |
Movement: 3-18* |
Good Spotted Overhaul recommended, at buyer's expense |
Dial: 4-8-01 |
Fair Slightly scratched HANDS Original |
Notes
The Clifford Magnetic Escapement
Invented by Cecil F. Clifford, BSC, FBHI, in 1938 and was experimented upon during World War II with the aim of producing a silent time bomb for naval use. The theory being that as the escapement does not ?tick? it would be undetected by sonar. The escapement consists of a flat pierced sinusoidal escape-wheel made of a magnetisable material called ?Mumetal? mounted horizontally, and a flat upright ?detent? terminating in two prongs allowing the escape wheel teeth to pass through. After the war, Clifford approached various firms 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 and the company became Horstmann Clifford Magnetics Ltd in 1948, in order to produce 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 fitted, 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 nor 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 1960?s had magnetic escapements similar to the Hamilton prototype and 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.