- Museum number
MOVEMENT OF A LEVER WATCH.
Full-plate construction with a separate bridge for the barrel and fusee.
Harrison's maintaining power.
Savage-type lever escapement.
Hour hand not original; minute and seconds hands missing.
- Production date
Diameter: 39.50 millimetres (back-plate)
Diameter: 44 millimetres (front-plate)
Thickness: 11.60 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Thomas Cummins
London, c. 1820
Movement of a ratchet tooth lever watch with a wide impulse jewel.
Signature: On the back plate 'Thos Cummins. LONDON. No 526'. i.c
Dial & Hands: The dial missing. A blued-steel spade pattern hour hand survives, the minute and seconds hands are missing.
Dial-plate: None intended. There is, however, no provision for a hinge, the movement appears to have been held in the case by three transverse screws in the edge of the recessed front plate.
Dust-cap: None intended.
Ebauche Marks: 16 0
Frame: Full plate layout, the back plate supported by four turned pillars. There is no separate barrel bridge, even though the back plate has been machined to make it appear that there is one. The back plate is cut away to accommodate the balance, exposing a portion of the barrel and fusee. A guard plate, retained by a screw, is fitted between the barrel and the escapement. A separate bridge on the front plate provides bearing for the third, fourth and escape wheel pivots. The elongated oval balance bridge is undecorated.
Fusee, Barrel and Mainspring:
Fusee: 53-turn fusee with Harrison's maintaining power with a steel maintaining ratchet wheel.
Barrel: internal diameter 16.4 mm, height 2.85 mm, the barrel and cap un-gilded.
Mainspring: height 2.7 mm, thickness 0.23 mm.
Barrel Arbor: diameter 5.5 mm, not snailed.
Train: Gilded train, the centre wheel solid, the third and fourth wheels with five crossings.
Jewelling: Jewelled bearings for the third wheel in the front plate and then all of the pivots onwards including the lever. The escapement with ruby endstones except for a diamond in the balance cock.
Escapement: An acute-angle layout ratchet tooth lever escapement with a wide impulse jewel. The gold lever has a curiously shaped notch resembling one of the Savage notches (see cat. no 235 (registration no. 1958,1201.1034)).
The enclosed pallet stones have flat acting faces.
The brass escape wheel has three crossings.
An equal impulse escapement.
No. of teeth embraced 32
Balance and Spring: A split bimetallic balance with brass compensation and quarter screws. Balance diameter 21.5 mm, thickness 1.4mm. Flat spiral blued-steel spring of 9 turns attached to a polished steel stud screwed to the back plate (screw missing).
Means of Regulation: An index on the balance bridge registers against a divided scale with 'F' and 'S' engraved on the back plate.
Train Counts and Beat Rate:
Great wheel 70 (fusee)
Centre wheel 64 pinion 12
Third wheel 60 pinion 8
Fourth wheel 63 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: Key wound.
Movement: diameter 44.0 mm, height 11.3 mm, pillar height 3.3 mm.
Provenance: Formerly in the Ilbert collection. Ilbert purchased this movement from Collet 21/1/1933.
Exhibited: Newcastle-under-Lyme Museum, 1977. See Alan Treherne, The Massey Family, cat. no. 59.
- Not on display
Latest: 2 (2017)
Screw for balance-spring stud now missing.
- 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.0972 (Ilbert Collection)
Previous owner/ex-collection number: M331 (Ilbert Ledger)