Important Modern and Vintage Timepieces.
Geneva, Nov 13, 2010
LOT 467
Ridel ? Table Regulator With standard & Decimal Time & French Revolutionary Calendar Ridel à Paris. Made circa 1794. Extremely fine and equally rare, mahogany and gilt-bronze, 15-day going, center-seconds, hour and half-hour striking table regulator with half-second beating pin-wheel escapement, standard time and simultaneous Revolutionary decimal time, Revolutionary calendar, fine painted on enamel moon phases, lunar calendar and gridiron pendulum.
CHF 40,000 - 60,000
USD 40,000 - 6,000 / EUR 30,000 - 45,000
C. Mahogany, architectural, polished, stepped entablature, glazed on four sides with gilt-bronze reeded filets, hinged back door, gilt-bronze feet, beaded hinged bezel, domed glass. D. White enamel convex, Arabic numerals for the standard time, outer gilt and black dot minute divisions, outermost blue Arabic numerals 1-30 for the Revolutionary calendar, subsidiary dial with Arabic numerals 1-10 for the decimal hours, outer minutes divided into 100, aperture for the moon phases with extremely finely painted on enamel disc with gold paillon stars, lunar calendar on the edge. Pierced gilt brass hands for the hours, blued steel hands for the calendar and center-seconds. M. 13 ½ cm., gilt brass, circular plates, large going barrels for both trains, gearing for the decimal time on the dial plate, pin-wheel escapement on the back plate with steel pallets, knife-edge suspension, 9-rod steel and brass gridiron pendulum with gilt brass lenticular bob and rating nut, outside count wheel striking on a bell. Dial signed. Dim. 53 x 26 x 20 cm.
| Grading System | |
|---|---|
Grade: |
|
Case: 2-23 |
Very good Later |
Movement: 2 |
Very good |
Dial: 2-24-70-01 |
Very good Slightly chipped ENAMEL AND VARIOUS TYPES OF DECORATION Hairline HANDS Original |
Notes
Decimal Time The day was divided into ten hours of 100 minutes each, each minute being subdivided into 100 seconds. Thus, for example, 12:30 PM was 5:20:83.3 in decimal time. The decimalization of time was introduced on November 24, 1793. The new division of time proved impossible to enforce, and was suspended on April 7, 1795. Thus, there was a period of less than 18 months during which these timepieces were produced, which explains why they are so rare. The French Republican Calendar or French Revolutionary Calendar was in use during the French Revolution, and used by the French government for about 12 years from late 1793 to 1805, and for 18 days in 1871 in Paris. See: ?Revolutionary Time?, Antiquorum, Vox Magazine, 2004.
Ridel à Paris Was working rue aux Ours, circa 1800. Specialised in skeleton and complicated clocks, he made outstanding clocks with the dials enamelled by eminent craftsmen such as Coteau and Dubuisson. The signature Ridel is found on most of the finest moon-phase decimal clocks.
The Pin-Wheel Escapement This escapement was particularly popular in France and was invented by Louis Amant in 1741. The teeth of the escape wheel are replaced by pins standing vertically from the plane of the wheel. A swinging pair of levers attached to the pendulum allows the pins to ?escape? one by one; this also impulses the pendulum. The pin-wheel escapement is quite accurate and only needs a small pendulum arc making it suitable for precision clocks.
Gridiron Pendulum The rod is composed of separate bars of brass and steel rods having different coefficients of expansion, so that the pendulum has the same length at any temperature. John Harrison used 9 bars of brass and steel when he first introduced the design in 1729. Some gridiron pendulums use fewer rods and different metals.