Important collector's watches, wristw...

Hotel Richemond, Geneva, Apr 13, 2002

LOT 472

Gregson à Paris, 1794 or first half of 1795. Fine and very rare silver Revolutionary watch with decimal Revolutionary dial and traditional duo-decimal 24-hour dial.

CHF 9,000 - 11,000

EUR 5,300 - 6,500 / USD 5,400 - 5,500

Sold: CHF 16,100

C. Two-body, Directoire, polished. D. White convex enamel, Red Arabic Revolutionary hours with 100 dots for Revolutionary minutes, every tenth minute marked as a small lily of the valley flower, 25-minute Arabic markers, outer duo-decimal Roman chapter calibrated for 24 hours (twice XII) with outer duo-decimal minute divisions with fifteen-minute Arabic figures. M. 42 mm., hinged, gilt brass full-plate with cylindrical pillars, fusee and chain, verge escapement, plain brass tree-arm balance, flat balance spring, continental cock. Signed on dial and movement, case punched with casemaker?s mark ?DP?. Diam. 52 mm.


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Grading System
Grade: AAA

Excellent
Case: 3

Good
Movement: 3*

Good

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

Good

HANDS Original

Notes

After the French Revolution a new digital calendar was adopted, the entire time measurement system was changed. The revolutionary year was divided into 12 equal months having 30 days each and an additional 5-day (6-day in a leap year) holiday month; each month was divided into three decades, each having 10 days. The 24-hour day was divided into ten hours, each having 100 minutes, each minute subdivided into 100 seconds. The law was introduced on 24 November, 1793, and the provision for decimal hours was suspended on 7 April 1795. We have a period of 18 months during which these watches were produced. The Republican calendar law was effective until 9 September 1805. When the law was introduced, the demand for Revolutionary watches was greater than the system could produce. The standard practice was to convert a duo-decimal watch from the stock made few years before. For that a watchmaker had to replace the balance spring with a longer one to make the center wheel rotate 10 times per day instead of 12 and change the motion train to accommodate 1:10 ratio instead of 1:12. The 24-hour is achieved by additional motion train for the duo-decimal minutes.