The Art of American Horology & Colle...

New York, Nov 28, 2001

LOT 123

Elgin, Model 600, No. 202, made for the U.S. Navy in 1943.Fine and very rare, two-day marine box chronometer with 56-hour winding indicator.

USD 3,000 - 4,500

C. brass bowl with threaded glazed bezel gimbaled in three-body brass-bound mahogany box with glazed panel in the top under hinged lid with fitted catch, brass handles, plate with the signature, Breguet-type key in a corner plate, key-lock in front, gimbals ring locked by swiveling arm pressing sideways against the base of the cylinder. D. silvered, Roman hour numerals, Arabic seconds on subsidiary dial at 6 o'clock, up/down indicator at 12 o'clock. Blued steel "Spade" hands. M. 87 mm, nickel, fll plate with recess for the balance, "fausses côtes" decoration, baluster pillars, secured by screws, fusee and chain, detachable Earnshaw spring-detent escapement, bimetallic anibal-brass Guillaume balance with free sprung special steel alloy balance spring with terminal curves, four cylindrical temperature adjustment weights, two mean time adjustment nuts, jeweled to the third wheel.Signed on the dial and movement. Movement also engraved "U.S. NAVY, BU. SHIPS, NO 202, 1943."Dim. Height 19cm, width and depth 18cm


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Grading System
Grade: AA

Very good
Case: 3-14

Good

Damaged
Movement: 3*

Good

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

Good

HANDS Original

Notes

The existence of another Elgin chronometer with original papers and outer box in such an excellent condition is not known.Elgin's marine chronometers are very rare. During World War II, the US Navy hired Elgin to produce 3,000 chronometers at $541 per unit. Elgin delivered the first one in 1944, however the war in Europe soon ended and the contract was cancelled after only a limited number had been produced.Elgin 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 changes in elasticity. These properties are very different from those of two other famous alloys invented by Guillaume, Invar and Elinvar. At the end of the 1800's, 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 aproximately a linear function of temperature, while the modifications caused by change in elasticity of a balance spring are approximately a quadratic function. Thus, it equals zero at only two temperatures, causing secondary error. Countless attempts were made to eliminate the Middle Temperature Error, usually by means of auxiliary compensation devices. In 1899, Guillaume noticed that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. This, combined wth brass in bimetallic lamina, makes its expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume balances, or, as their inventor called them, integral balances. When combined with special balance springs, they exhibit remarkable temperature stability, on occasion not exceeding 1/50 second per day at 1oC.