- Museum number
BLUED-STEEL CASED LEVER WATCH WITH DIGITAL HOURS AND MINUTES.
Lever escapement; jumping hour and minutes.
Enamel dial with apertures.
Blued steel case.
- Production date
Diameter: 51 millimetres (case)
Diameter: 41.40 millimetres (dial)
Thickness: 16.70 millimetres
- Curator's comments
Compare with CAI.270
Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by International Watch Co
Schaffhousen, Switzerland, c. 1890
Digital display watch with club tooth lever escapement.
Signature: The back plate bears the trade mark "IWC" in a round cartouche. The number 7329 on the front plate.
Case: Gun metal open face case. The bow will no longer hold the winding stem in position as it is not the original and not correctly formed to penetrate the stem groove.
Dial and Hands: Flat enamel dial with subsidiary seconds. The dial marked "HOUR" in black against the hours aperture "MINUTES" in red over the minutes aperture and "Patent Automatic Timekeeper Swiss" in black around the edge of the dial. In the counter enamel, in red, 3. The dial cracked around the `Tim' of the word Timekeeper. The seconds hand blued-steel.
Ebauche Marks: Under the dial is stamped PATENT PALLWEBER.(1)
Frame: Bar movement.(2) All the parts stamped 9.
Barrel and Mainspring: Going barrel I. diameter 17.1 mm., height 3.0 mm.
Mainspring: height 2.75 mm., thickness 0.21 mm.
Arbor: diameter 5.45 mm., snailed.
Hooking: T piece.
Train: Brass wheels gilded with five crossings, the gold escape wheel with four. Good quality train.
Jewelled: From the third onwards the jewels rubbed in, ruby endstones to the balance.
Escapement: Club tooth lever, straight line layout, short lever, double roller, impulse pin elliptical Pallet stones exposed, the impulse faces convex, the locking faces flat. Escape wheel gold. A mixed escapement.
Number of teeth embraced 3½.
Balance and Spring: A split bimetallic balance with gold compensation and quarter screws. Balance diameter 16.3 mm., thickness 1.2 mm. Blued-steel flat spiral spring with 12 turns.
Means of Regulation: Index on the balance cock registering against a divided scale with engraved "F S".
Train Counts and Beat Rate:
Great wheel (barrel) 90
Centre wheel 80 pinion 10
Third wheel 45 pinion 10 with a wheel of 5 teeth mounted on it.
Fourth wheel 70 pinion 10
Escape wheel 15 pinion 7
Beat Rate: 18,000
The Digital Display Work: The third wheel revolves once in 5.0 mins. The wheel of 5 mounted on it drives a wheel of 10 so this revolves the minutes disc once in 10 mins. This has one tooth which indexes the '10's of minutes' wheel a twelfth of a turn each revolution i.e. once in 120 minutes. This wheel is numbered 012345012345. Two teeth on a smaller wheel mounted beneath this disc indexes the hour wheel through a wheel of effectively 12 teeth, i.e. once every 12 hours.
Winding System: Two piece stem, side set positive keyless work with the provision of a second lever to disengage the digital discs from the going train whilst the hands are being set. The push slide that is operated by the side set pin is broken.
Dimensions: Case diameter 50.9 mm., height 16.8 mm. (over the glass).
Movement diameter 43.3 mm., height 11.0 mm.
Provenance: Formerly in the Ilbert collection. Ilbert bought this from Gould in August 1947
(1) The patent referred to is number 25042 dated 18th May 1883. It covered the type of digital display and was in use in watches made by the International Watch Co between 1885 and 1890. See 'IWC Uhren' by Richard Meis, Klagenfurt 1985 p. 46.
(2) This is International calibre 42. See 'IWC Uhren' pp 52, 53. Idib.
- Not on display
- Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.1181 (Ilbert Collection)
Previous owner/ex-collection number: Q138 (Ilbert Ledger)