- Museum number
WATCH MOVEMENT WITH FULL-PLATE, KEYLESS-WORK, GOING-BARREL, AND RATCHET-TOOTH LEVER-ESCAPEMENT.
Full-plate, going-barrel, English rocking-bar keyless-work, barrel-bridge unfinished, ratchet-tooth lever-escapement, Earnshaw compensation balance.
Dial; enamel, 2-piece, white with black I-XII numerals, sunk subsidiary seconds dial marked 10-60.
Hands; gold spade hands, minute hand broken, seconds hand missing.
- Production date
Diameter: 38.60 millimetres (back-plate)
Diameter: 41.50 millimetres (dial)
Thickness: 11.20 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
England, c. 1890
Movement of ratchet tooth lever watch
Signature: On the back plate 'No 41458'
Case: Missing, the movement held in the case by a locating stud and two dog screws.
Dial & Hands: A flat dial with a sunk subsidiary seconds dial. Gold spade pattern hour and minute hands, the minute hand broken and partly missing, the seconds hand missing.
Dial-plate: None intended.
Dust-cap: None intended.
Ebauche Marks: 41458 12 0 CS.(1)
Frame: Full plate layout, the back plate supported by four turned pillars and secured by screws. The barrel bridge is not gilded.(2) The balance cock is engraved all over with foliate scrolls. The number 458 is punched on the underside of the potence, the balance cock foot and the combined third and fourth wheel bridge.
Barrel and Mainspring:
Barrel: going barrel with four-turn Geneva stopwork; internal diameter 16.0 mm, height 2.5 mm.
Mainspring: height 2.25 mm, thickness 0.21 mm.
Barrel Arbor: diameter 4.9 mm, not snailed.
Train: Brass wheels gilded, the centre wheel solid, third and fourth wheels with five crossings. One tooth of the centre wheel is missing.
Jewelling: Jewelled bearings for the fourth wheel onwards in the front plate except for the pallets. No fourth jewel in the back plate. The escapement jewelled (including the pallets in the back plate) and in screwed settings. Ruby endstones for the escapement.
Escapement: An acute-angle layout ratchet tooth lever escapement with short lever, single roller and D-shaped impulse pin. The enclosed pallet stones have convex impulse and locking faces. A slight chamfer on the locking corner of the exit stone.
The brass escape wheel has three crossings.
An equal impulse escapement.
No. of teeth embraced 32.
Balance & Spring: A split bimetallic balance with gold compensation and quarter screws, balance diameter 17.6 mm, thickness 1.3 mm. Blued-steel flat spiral spring with 14 turns pinned to a polished steel stud screwed top the back plate.
Means of Regulation: An index on the balance cock registers against a divided scale with 'Slow' and 'Fast' engraved on the balance cock table.
Train Counts and Beat Rate:
Great wheel 75 (barrel)
Centre wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 64 pinion 8
Escape wheel 15 pinion 7
Beat Rate: 16,200
Motion work: cannon pinion 12,
minute wheel 36, minute pinion 10
hour wheel 40
Winding System: Side-set rocking bar keyless work. A square left on the barrel arbor so that the watch may be wound with a key when being worked upon by a watchmaker.
Movement: diameter 41.5 mm, height 11.0 mm, pillar height 2.8 mm.
Provenance: Formerly in the Ilbert Collection.
(1) Charles Scarisbrick, ebauche maker of Prescot
(2) It is possible that this watch movement was left with its barrel bridge ungilded so that the retailers name could be engraved upon it prior to sale. The watch does, however, show evidence of having been used, suggesting that the present barrel bridge is a replacement for an original gilded and signed bridge.
- Not on display
Latest: 3 (2017)
3 (Feb 1996)
- 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.3134 (Ilbert Collection)