Important Modern & Vintage Timepieces

Hong Kong, Apr 28, 2019

LOT 429

BARRAUD BY EARNSHAW POCKET CHRONOMETER WITH "SUGAR-TONG COMPENSATION"; SILVER

HKD 23,000 - 31,000

CHF 3,000 - 3,950 / USD 3,000 - 4,000

Silver, open-face, key-winding, round-shaped, pocket chronometer, with subsidiary seconds at 6 and special temperature compensation.


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Grading System
Grade: AAA

Excellent
Case: 3-23

Good

Later
Movement: 3*

Good

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

Good

HANDS Original

Brand Paul Philipp Barraud

Model made by Thomas Earnshaw, London

Year circa 1800-1805

Movement No. 31 / 5 815

Calibre  19''', full plate, gilded brass, with fusee and chain, spring detent escapement (Earnshaw-type), monometallic balance (gilded brass) and blued steel flat hairspring, bimetallic temperature "sugar-tong compensation"

Material silver

Caliber 19''', full plate, gilded brass, with fusee and chain, spring detent escapement (Earnshaw-type), monometallic balance (gilded brass) and blued steel flat hairspring, bimetallic temperature "sugar-tong compensation"

Dimensions Ø 56 mm.

Signature dial and movement

Notes

The “sugar-tong compensation”, an invention of Thomas Earnshaw Although Thomas Earnshaw (1749-1829) made pocket watches with bimetallic balances and free-sprung helical springs, he equally often turned them out with an uncut flat monometallic balance, flat hairspring, regulator and compensation curb. This latter is a curious arrangement with two bimetallic arms, one pin on each end. Instead of sliding along the balance-spring the gap between the two pins widened in cold weather and closed in hot, which has the same effect. Owing to its pincer-like appearance and action, Earnshaw’s curb is usually known as a “sugar-tong compensation”. It is thought that these watches were for clients who needed a watch that could withstand robust use rather than watches with the heavier bimetallic balances that could easily break the balance pivots if subjected to shock. This invention must date from circa 1795. According to Cedric Jagger (1920-?), English horologist (Former Keeper of the Clockmakers’ Museum in Guildhall London), the pocket chronometers of this type, with “sugar-tong compensation” signed “Barraud”, were in fact produced by Thomas Earnshaw and sold by Paul Philipp Barraud (1750-1820). They are today referred to as being of the “Earnshaw Series”. Very few survived, seven of them are known (see list below). Several Earnshaw’s movements (with “sugar-tong compensation”) were left in “gray” by Thomas Earnshaw and subsequently finished, cased and sold by his son, Thomas Earnshaw Jr., in the 1820’s-1830’s. We also know from the very late-18th century and / or early-19th century, some chronometers with “sugar-tong compensation” made, signed and / or retailed by Robert Best (a foreman in the Earnshaw’s workshop), James Mc Cabe (1748-1811) and Parkinson & Frodsham, the house founded in 1801 by William Parkinson († c.1842) and William James Frodsham (1779-1850). John Roger Arnold (1769-1843) used circa 1810 a kind of compensation which is probably inspired by Earnshaw’s, who was the great competitor of his father, John Arnold Barraud, Paul Philip, London