- Museum number
NICKEL-SILVER CASED LEVER WATCH.
3/4-plate; going barrel.
Pin-pallet lever escapement; keyless winding; manual hand set.
White enamel dial; hours I-XII; minutes 15-60.
Diameter: 55 millimetres (case)
Diameter: 44.80 millimetres (dial)
Thickness: 20.60 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
ANONYMOUS but by Reconvillier
Switzerland, c. 1910
Watch with a pin pallet lever escapement
Signature: On the movement in a round cartouche is 'SYSTEME ROSKOPF' with at its centre a star.
Case: A nickel case, open face with a hinged bezel and snap on back. On the outside of the case back was a cartouche with the legend 'PATENT ROSKOPF' but this is almost entirely rubbed away. Its form can be inferred from registration no. 1958,1201.1095) which has an almost identical case again with a rubbed back but what was present can still be seen on the inside of the case. Also 16 6 and what was probably a 3 but this also rubbed. Inside the back is 1 and in an oval cartouche 'C H'. A bulls eye glass.
Dial and Hands: An enamel dial with black Roman numerals and minute marks with the minutes numbered at 15, 30, 45 and 60. Hair line cracks in the dial. Typical early Roskopf hands of brass with the minute hand with a tail.
Ebauche Marks: None but on the back plate is a representation of a propeller and a 0.
Frame: Brass plates, the back plate supported by 3 pillars and secured by screws. Cocks for the escape wheel the pallets and the balance, these all mounted on the sub plate which is fixed to the front plate. The sub plate is split and is provided with a screw, turning which can alter the depth between the escape wheel and the pallets.
(See registration no. 1958,1201.1092 for a similar arrangement).
A bridge covers the barrel ratchet wheel and its ratchet. The ratchet spring is broken and partly missing. Stamped, most unusually, on the side of the balance cock is 7. The front plate of this movement is 2.4 mm. thick.
Barrel and Mainspring: Going barrel with the brass cover carrying the minute wheel which is mounted friction tight. Barrel inside diameter 23.5 mm., inside height 3.3 mm.
Mainspring height 3.1 mm., thickness 0.28 mm.
Arbor: Diameter 7.0 mm., snailed
Hooking: A slipping mainspring. An outer turn of thicker spring moves from one of the four notches in the barrel wall to the next when the spring is fully wound. The mainspring is hooked to this thicker spring.
Train: The brass wheels with five crossings, the steel escape wheel with four.
Jewelled: At the escape wheel and pallets. The balance with jewel holes and with ruby endstones. The jewels rubbed in.
Escapement: A pin pallet escapement, obtuse angle layout, a long lever and effectively a double roller. A nickel silver impulse finger. A steel escape wheel and lever, the dart of brass. The pins of steel.
An equal impulse escapement.
Number of teeth embraced 3 ½.
Balance and Spring: A brass three armed balance with a rounded rim. Balance diameter 17.7 mm., thickness 0.7 mm. The top balance pivot broken.
The flat spiral blued-steel spring with 9 1/3 turns.
Means of Regulation: An index on the balance cock but no divided scale. 'A R' stamped on the cock.
Train Counts and Beat Rate:
Great wheel (barrel) 128 Rotates once in four hours.
Centre wheel 84 pinion 8
Third wheel 60 pinion 7
Escape wheel 18 pinion 6
Beat Rate 17,280
Motion Work: Cannon pinion 20, minute wheel 80, minute pinion 24, hour wheel 72
Winding system: The stem has pinned to its extension within the case the winding pinion and this remains in the case when the movement is removed. The hands are set manually from the front, this being facilitated by the hinged bezel.
Dimensions: Case diameter 55.1 mm., height 20.8 mm.
Movement diameter 47.8 mm., height 19 mm.
Provenance: Formerly in the Ilbert collection.
- Not on display
- Latest: 4 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.1094 (Ilbert Collection)
Previous owner/ex-collection number: P292 (Ilbert Ledger)