- Museum number
Pin lever escapement; later balance and cocks.
- Production date
Diameter: 57 millimetres
Thickness: 12.80 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Maker anonymous but probably Pichon (the ebauche by Japy)
Switzerland, c. 1820
Pichon type watch with an early pin pallet lever escapement.
Case: The middle and glazed bezel of a brass case, made to house the movement, the back is missing. There is also an adaptor ring to increase the movement diameter to accommodate the dial.
Dial and Hands:
A domed dial with black Roman numerals and minute circle. The dial secured by small screws at III and IX o'clock, one of these screws is missing. The dial chipped and with hair line cracks. Gilt moon hands.
Ebauche Marks: JAPY 10 406
Frame: A Lepine layout, with a standing barrel and a cock for the centre, a combined cock for the third and the escape wheel, and cocks for the balance and the pallets. The latter two cocks are not plated, with a poor finish and not original.
Barrel and Mainspring: The standing going barrel has Geneva stopwork with four turns.
Barrel outside diameter 21.4 mm., outside height 3.2 mm.
Mainspring height and thickness not determined.
Arbor: not accessible.
Train: The brass wheels are not plated and have five crossings. The escape wheel with four crossings.
Jewelled: Only the escape wheel pivot holes are jewelled and these jewels are ruby endstones. Coquerettes to the balance and lever holes in the front plate. The coquerette not fitted to the replacement balance cock.
Escapement: A pin pallet escapement, right angle layout, long lever, single roller with an elliptical impulse stone. A large diameter escape wheel with 30 teeth. The lever is of steel and not original, the steel pallet pins are D shaped. The pallet staff is screwed in.
An equidistant locking escapement.
Number of teeth embraced 3 ½.
Balance and Spring: A three arm gilded monometallic balance with a plain rim. Balance diameter 16.2 mm., thickness 0.6 mm.
A flat spiral blued steel spring with 11 turns.
Means of Regulation: None now fitted.
Train Counts and Beat Rate:
Great wheel (barrel) 80
Centre wheel 95 pinion 12
Third wheel 95 pinion 6
Escape wheel 30 pinion 6
Beat Rate 15,041.667
Motion Work: Cannon pinion 12, minute wheel 36, minute pinion 10, hour wheel 40.
Winding system: Keywound.
Dimensions: Case diameter 57.2 mm., height approximately 10 mm., over the glass.
Movement: Diameter 51.0 mm., height 11.15 mm.
Provenance: Formerly in the Ilbert collection.
Note: For a remarkably similar watch see Chamberlain page 70 and 71. However there are 32 teeth in the escape wheel of this watch.
- Not on display
Latest: 3 (2017)
3 (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.1229 (Ilbert Collection)
Previous owner/ex-collection number: L124 (Ilbert Ledger)