3,450 CHF
Thomas Mercer, Ltd. St. Albans, England, No. 19851. Made in 1952. Fine mahogany two-day marine chronometer with Volet balance. 82 mm., gilt brass full plate with recess for the mainspring barrel, circular pillars secured by screws, fusee and chain, 13 jewels, detachable Earnshaw spring-detent escapement, bimetallic ovalizing Volet compensation balance with freesprung white metal helical balance spring with terminal curves, four cylindrical temperature adjustment weights, two mean time adjustment nuts, jeweled to the third wheel. Dial and movement signed, case with a plate engraved “supplied by C.L. Malmsjö Södra Hamngatan, Goteborg”. Height 16 cm., width and depth 18 cm. Notes The Volet balance consists of an arm made from one metal, usually Invar, and the rim from another, usually steel. The difference between their thermal expansion coefficients causes the rim to assume an elliptical shape when subjected to temperature changes. It appears that the American company Hamilton was the first to use this type of balance in chronometry with exceptional results: daily variations not exceeding 1/50 sec.
Auctioneer:
Antiquorum
Date:
2005-11-13
