- Museum number
NICKEL-PLATED CASED LEVER WATCH.
Pin-pallet lever escapement; keyless; rocking bar.
White enamel dial.
Open-faced nickel-plated case with glazed dome (glass missing).
Diameter: 46.10 millimetres (case)
Diameter: 34.50 millimetres (dial)
Thickness: 12.40 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Roskopf
Switzerland, c. 1900
Watch with pin pallet lever escapement.
Signature: On the dial 'SYSTEME ROSKOPF' set out in a circular manner, and in red at its centre in black is a Helvetia cross with a red spot at its centre. beneath the circle, also in red, is 'SWISS MADE'. Below the dial centre is 'PATENT'. On the back of the case is 'SWISS MADE' and 'SYSTEME ROSKOPF' with two small Helvetia crosses set out in a circular manner around a stylised rose. Around the outer part of the case back are representations of medals.
Case: A nickel three piece case with a hinged back and a snap on bezel. A decorated bow. A glazed bezel for viewing and protecting the movement. The glass is missing.
Dial & Hands: Unexpectedly the dial is of enamel. Roman numerals the 12 in black and a black minute circle with the numbers 15, 30, 45, and 60. The dial secured by two screws from the front. Gilt hands basically of spade design.
Ebauche Marks: none.
Frame: A nickel silver movement. A bridge for the barrel and train wheels. Cocks for the pallets and the balance. The movement damascened on the back.
Barrel and Mainspring: A going barrel with the minute wheel mounted friction tight on the cover.
Barrel: internal diameter 18.6 mm., height 2.0 mm.
Mainspring: height 1.9 mm., thickness 0 .23 mm.
Barrel Arbor: diameter 4.85 mm, snailed.
Hooking: Pressed in from the barrel wall.
Train: The brass wheels not gilded, the centre, third and fourth wheels with five crossings. The steel escape wheel with four.
Jewelling: Only an endstone in the balance cock.
Escapement: An obtuse angle layout pin pallet lever escapement with long lever, effectively a double roller with a brass impulse finger. The pallet pins of steel. A steel escape wheel with four crossings.
An equal impulse escapement.
No. of teeth embraced 3½.
Balance & Spring: a monometallic balance without screws. Balance diameter 13.3 mm., thickness 0.57 mm. A blued-steel flat spiral spring with 12.5 turns.
Means of Regulation: An index on the balance cock registers against a divided scale with 'F S' and 'A R' engraved on the balance cock table.
Train Counts and Beat Rate:
Great wheel 68 (barrel)
Centre wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 60 pinion 8
Escape wheel 15 pinion 6
Beat rate 12,240
Motion work: cannon pinion 16
minute wheel 64 , minute pinion 18
hour wheel 54
Winding System: Normal side set positive keyless work.
Case: Diameter 46.2 mm., height 12 mm.
Movement: Diameter 37.2 mm., height 9.2 mm.
Provenance: Formerly in the Ilbert collection.
- Not on display
Latest: 4 (2017)
3 (1994) Glass broken in two pieces.
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: 20MA (Ilbert Leger)
Previous owner/ex-collection number: CAI.1090 (Ilbert Collection)