- Museum number
MOVEMENT AND DIAL OF A LEVER WATCH.
Savage-type lever escapement; escape and pallet jewels blind.
Silver engine-turned dial; sunk subsidiary seconds.
Blued-steel Breguet hands.
- Production date
Diameter: 50.60 millimetres
Thickness: 9.90 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by James Ferguson Cole.(1)
London, c. 1840
Movement of a ratchet tooth lever watch with a wide impulse jewel.
Signature: 'JAMES F. COLE. LONDON. No qs.' on the rear of the front plate.
Case: Missing, the movement was originally held in its case by two dog screws and positioned by two pegs.
Dial & Hands: Silver dial with an engine-turned recessed centre. The back of the dial is scratched 'J F Cole 1/2', to mark the position of 12 o'clock, '8/99 7/1900' and 'Grohe No 112 2/56'. There is also another signature which has not been deciphered. Blued-steel moon pattern hour and minute hands and a blued-steel seconds hand with a long moon tail. This hand is of an unusual construction with an integral pipe.
Dial-plate: None intended, the dial is attached directly to the front plate by two short feet and pins.
Dust-cap: None intended.
Ebauche Marks: None.
Frame: Lepine construction, built up on a thick front plate. There are cocks for the barrel, the centre wheel, the third wheel, the pallets and the balance, as well as a combined cock for the fourth and the escape wheels. The cocks are finely engraved with acanthus leaf decoration.
Barrel and Mainspring:
Barrel: going barrel with the original stop work now removed. The ratchet wheel and combined blued-steel click and spring are of Breguet style.
Barrel internal diameter 18.8 mm, height 0.23 mm.
Mainspring: height 2.9 mm, thickness 0.23 mm.
Barrel Arbor: A two-part arbor with a brass head, diameter 6.3 mm, not snailed.
Train: A high quality train with well made wheels and high count pinions. All the wheels gilded, the centre, third and fourth wheels with six crossings. The centre and fourth pinions have been left long, extending over the whole available length of the arbor.
Jewelling: Jewelled bearings for the centre wheel onwards except for the centre hole in the front plate. The conical pivots of the escape wheel, pallets and the rear balance pivot run in blind cone shaped jewel holes.(2) These blind jewels are fabricated from ordinary jewels put together so that there is no gap between them and rubbed in as a permanent assembly. All the other jewels are also rubbed in except for those in the balance cock which are normal with a screwed in setting and a diamond endstone.
Escapement: A ratchet tooth lever escapement in an almost straight line layout with a long lever and single roller. The very wide impulse jewel on the table roller gives a similar unlocking action to a Savage two pin escapement. The enclosed pallet stones are convex on the acting faces. The heavy lever has a long tail, as if for poising but the assembly is not poised. The banking pins are on a detachable brass plate. The polished brass escape wheel has three crossings.
A mixed impulse escapement.
Number of teeth embraced 32.
Balance and Spring: A split bimetallic balance with gold quarter and compensation screws. Diameter 18.2 mm, thickness 1.2mm. A later blued-steel flat spiral spring of 15 turns with no terminal curve. From the layout, it is almost certain that the original spring had a raised terminal curve. There is a Breguet-type stud under a steel plate on the balance cock for radial adjustment of the spring.
Means of Regulation: An index on the balance cock registers against a divided scale with 'F' and 'S' engraved on the balance cock table.
Train Counts and Beat Rate:
Great Wheel 90 (barrel)
Centre wheel 80 pinion 10
Third wheel 75 pinion 10
Fourth wheel 75 pinion 10
Escape wheel 16 pinion 8
Beat rate: 18,000
Motion Work: cannon pinion 10
minute pinion 12, minute wheel 40
hour wheel 36
Winding Mechanism: Key wound.
Movement: diameter 50.6 mm, height 11.0 mm, frame height 7.1 mm.
Provenance: Formerly in the Ilbert Collection. Purchased by Ilbert from Malcolm Gardner in 1941.
(1) James Ferguson Cole, 1798 - 1880. For an obituary see HJ Vol. XXII, (February 1880) p. 84.
(2) This method of jewelling is most uncommon, it is usually only met with in Breguet's parachute assembly where cone pivots are used. See Daniels, Breguet p.331.
- Not on display
Latest: 3 (2017)
- 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.0946 (Ilbert Collection)
Previous owner/ex-collection number: Q86 (Ilbert Ledger)