- Museum number
Minute-repeating calendar chronograph.
Diameter: 47 millimetres (dial)
Thickness: 15 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Switzerland, c. 1900
Minute repeating watch movement with chronograph, lunar and date work and a club tooth lever escapement.
Dial and hands: A flat canister dial with hairline crack. Scratched on the back 13. Four sunk subsidiary dials; at the XII the date, at III the month, at VI the seconds and moon dial, at IX days of the week. Spade pattern hour and minute hands, all hands of blued-steel.
Ebauche marks: 1022 and 27
Frame: Bar movement, the calendar and moon work on a sub-plate which covers the repeating work. Repeating on two gongs. The chronograph work operated by a single push piece which indexes a castle wheel giving the three functions; stop, start and return to zero.
Barrel and Mainspring:
Recessed cover to the going barrel; I diameter 15.7 mm., height 2.5 mm.
Mainspring: height 2.5 mm thickness 0.21 mm
Arbor: diameter 5.4 mm., snailed
Train: Brass wheels gilded one side with five crossings, the escape wheel with four.
Jewelled: from the third onwards, the jewels rubbed in, ruby endstones to the balance pivots.
Escapement: Club tooth lever, straight line layout, long lever, double roller, impulse pin elliptical. The pallet stones exposed and with flat acting faces. Escape wheel of steel.
A mixed escapement.
Number of teeth embraced 3½.
Balance: An uncut bimetallic balance, diameter 15.3 mm., thickness 1.0 mm. Blued-steel flat spiral spring with 17 turns and with a terminal curve.
Means of Regulation: Index on the balance indicating against a divided scale with engraved 'F S' and 'A R'.
Train Counts and Beat Rate:
Great wheel (barrel) 84
Centre wheel 80 pinion 12
Third wheel 75 pinion 10
Fourth wheel 70 pinion 10
Escape wheel 15 pinion 7
Beat rate 18,000
Motion work: cannon pinion 12
Minute wheel 30, minute pinion 10
hour wheel 48
Calendar work: The calendar work is driven by a second wheel of 26 mounted above the hour wheel. This in turn drives two wheels of 52, A and B. A pin on A indexes the 31 toothed star wheel that carries the date hand. This star wheel in turn drives another wheel of 31 which by virtue of one long tooth indexes the star wheel of 12, i.e. the month wheel. The other wheel of 52, B, also has a pin that indexes both the star wheel of 7 (the day of the week wheel) and the star wheel of 50, the moon wheel.
Winding System: Side lever set positive keyless work.
Repeating Work: was operated by a slide in the case band. A continuously acting flirt operating lever. Speed control by a centrifugal brake.
Dimensions: Movement diameter 49.9 mm., height 13.0 mm.
Provenance: Formerly in the Ilbert collection. Ilbert purchased this from Arnold in 1936.
- Not on display
Latest: 3 (2017)
2 (Feb 1995)
- 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.1219 (Ilbert Collection)
Previous owner/ex-collection number: P116 (Ilbert Ledger)