- Museum number
GOLD-CASED LEVER WATCH WITH DIGITAL HOURS AND MINUTES.
bar movement, going-barrel.
Club-tooth lever escapement, split bimetallic balance.
White enamel dial with apertures for Arabic hours and minutes; subsidiary seconds. Signed.
Blued-steel seconds hand, hours and minutes on silvered discs.
Gold case, warranted 18K.
Jumping hours and minutes; digital; the third wheel has teeth removed, so it jumps round until a toothed part engages the fourth pinion.
- Production date
Diameter: 48.70 millimetres (case)
Diameter: 39.30 millimetres (dial)
Thickness: 14.90 millimetres
- Curator's comments
See Meis, R., IWC Uhren, Die "Schaffhauser und ihr Geschichte", 1985, pg.50-65
Compare with CAI.1181
Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by International Watch Co.
Schaffhausen, Switzerland, c. 1890
Gold cased watch with digital display and a club tooth lever escapement.
Signature: The dial signed "International Watch Co". The back plate bears the trade mark "IWC" in an oval cartouche. The number 1684 on the front plate and "PATENT PALLWEBER".(1)
Case: 18 ct gold open face case, both backs numbered 2422. On the inside of the outer back is "WARRANTED 18K J.W.Co".(2) On the outside of the inner back is "SIR JOHN BENNETT LD 65 & 64 Cheapside LONDON SWISS MAKE". Also "Maker to the Royal Observatory" and the Royal Arms. The pendant marked with the Swiss quality mark.
Dial and Hands: Flat dial with a subsidiary seconds dial. The dial marked "HEURES" in red against the hours aperture. The seconds hand blued-steel.
Ebauche Marks: 1684
Frame: Bar movement.(3) All the parts stamped 4.
Barrel and Mainspring: Going barrel I. diameter 17.1 mm., height 3.00 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. A gold escape wheel with four. A 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. A mixed escapement. Pallet stones exposed, the impulse faces convex the locking faces flat. Escape wheel gold. Adjustable banking pins.
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 10½ 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 with 5 gaps in the teeth,
Third wheel 45 pinion 10 (a wheel of 36 teeth also mounted on it. The third wheel is effectively a 50 tooth wheel).
Fourth wheel 70 pinion 10
Escape wheel 15 pinion 7
Beat Rate: 18,000.
The Digital Display work: The 3rd wheel revolves once in 5 minutes. The wheel of 36 mounted on it drives another wheel of 36 with a star wheel of 5 on the same axis. This indexes the minutes disc once in 10 mins. This has one tooth (now broken off) which indexes the `10's of minutes' wheel a sixth of a turn each revolution, i.e. once in 60 minutes. A tooth on a smaller wheel mounted beneath this disc indexes the hour wheel through a Geneva type wheel with 12 gaps, i.e. one revolution in 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.
Dimensions: Case diameter 48.8 mm., height 14.7 mm.
Movement diameter 43.1 mm., height 10.5 mm.
Provenance: Formerly in the Ilbert collection. Ilbert bought this from Malcolm Gardner 11/4/1932
(1) The patent referred to is number 25042 dated 28th May 1883. It covers the type of digital display and was in use in watches made by the International Watch Co. between 1885 and 1890. See I W C Uhren by Richard Meis, Klagenfurt 1985, p. 46.
(2) J W Co. - James Walker.
(3) This is International calibre 40. See Richard Meis I W C Uhren Klagenfurt 1985 pp 48, 49.
- Not on display
- Latest: 2 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.0270 (Ilbert Collection)
Previous owner/ex-collection number: M12 (Ilbert Ledger)