- Museum number
Lever escapement; unusual safety action.
- Production date
Diameter: 50.60 millimetres
Thickness: 11 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
France, c. 1830
Quarter repeating watch movement with club tooth lever escapement (but see under escapement)
Dial and Hands: Missing.
Dial-Plate: Secured by edge screws to the front plate.
Dust-Cap: A cuvette was fitted but this is now missing.
Ebauche Marks: 188
Frame: A bar movement. The going barrel constructed as a standing barrel, the ratchet wheel on the dial side with an extended pipe that pivots in the front plate.
Barrel and Mainspring:
Going barrel fitted with geared stopwork, the second gear missing. Slotted for a brace but none fitted.
Barrel I. diameter 17.2 mm., height 2.30 mm.
Mainspring: height 2.0 mm., thickness 0.20 mm.
Arbor: diameter 6.0 mm., not snailed.
Train: Gilded brass wheels, the centre wheel with five crossings, the third, fourth and escape wheels with four crossings.
Jewelled: At the balance pivots only, a ruby endstone for the upper pivot, a diamond endstone in the balance cock. A screwed setting in the cock, in the front plate the jewel hole is rubbed in.
Escapement: Club tooth lever escapement but with a short impulse planes on the wheel tooth. The wheel is steel. The ratio of wheel tip length to pallet length is approx. 1:3. There are two pins on the end of the pallet to give impulse to a steel radially mounted finger. The safety action is similar to L 9/5 but this ring has a single arm and a double rim.
The exit pallet has a straight impulse face but the entrance pallet impulse face is convex. The locking faces are flat.
An equal impulse escapement.
No of teeth embraced 3 1/2
Balance and Spring: Plain gold three armed balance, diameter 15.8 mm., thickness 0.7 mm. Flat spiral blued-steel spring with 6½ turns.
Means of Regulation: Index on the balance cock registering against a divided scale with engraved "A R".
Train Counts and Beat Rate:
Great Wheel (barrel) 78
Centre wheel 80 pinion 10
Third wheel 64 pinion 8
Fourth wheel 64 pinion 8
Escape wheel 14 pinion 8 The teeth of the wheel notched for oil retention.
Beat Rate: 17,920
Motion Work: cannon pinion 12, the minute wheel and the hour wheel missing.
Winding System: Keywound.
Repeating work. Rack driven ¼ repeating, the two gongs are of square section. The speed control is ??????? All or nothing work is fitted.
Dimensions: Movement diam. 51 mm, h. 10.6 mm.
Provenance: Formerly in the Ilbert collection. Ilbert purchased this from Malcolm Gardner 9/4/1933.
- Not on display
Latest: 4 (2017) -been treated (1993) but keep an eye on it
1 (Feb 1995)
- Acquisition date
- Acquisition notes
- Following the successful acquisition of the celebrated Ilbert collection of clocks (1958,1006 collection), prints and other related materials made possible by the generous donation of funds by Gilbert Edgar CBE Ilbert's watches were then acquired using funds provided by Gilbert Edgar, public donations and government funds.
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.1230 (Ilbert Collection)
Previous owner/ex-collection number: N35 (Ilbert Ledger)