Important collector's watches, wristw...

Hotel Richemond, Geneva, Apr 13, 2002

LOT 233

Thomas Mercer, Ltd. London, No. 19851, circa 1950. Fine mahogany two-day marine chro-nometer with winding indicator.

CHF 2,500 - 3,500

EUR 1,700 - 2,500 / USD 1,500 - 2,000

Sold: CHF 2,990

C. Brass bowl with threaded glazed bezel gimbaled in two-body mahogany box with glazed panel in the top under a hinged lid with a catch, gimbal ring locked by a swiveling arm pressing sideways against the base of the cylinder, two-body mahogany outer carrying box. D. silvered, Roman hour numerals, outer minute ring, Arabic seconds on subsidiary dial at 6 o'clock, up/down indicator at 12 o'clock. Blued steel "Spade" hands. M. 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 free-sprung helical 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, case with a plate engraved ?supplied by C.L. Malmsjö Södra Hamngatan, Goteborg?. Height 16 cm., width and depth 18 cm.


LOADING IMAGES
Click to full view
Image
Grading System
Grade: A

Good
Case: 4-15-21

Fair

Slightly rusted

Period
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-8-01

Good

Slightly scratched

HANDS Original

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 amazing results: daily variations not exceeding 1/50 sec.