- Museum number
GUN-METAL CASED LEVER WATCH WITH METRONOME.
Enamel dial; subsidiary seconds and metronome scale.
Gold hour, minute and seconds hands; blued-steel metronome hands.
Open-faced gun-metal case with gold bow, button and push-pieces.
- Production date
Diameter: 51.60 millimetres (case)
Diameter: 43.20 millimetres (dial)
Thickness: 12.60 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Switzerland, c. 1905
Watch with metronome and club tooth lever escapement.
Signature: Movement numbered 10170
Case: Gun metal open face case the inner dome numbered 603 the outer 6032011 BBX. The outside of the inner dome bears the inscription 'GRAND PRIX PARIS 1900'. Gold coloured bow, button and push pieces.
Dial and Hands: Dial with Arabic numerals, a sunk centre and two sunk subsidiary dials. That at the 12 showing the beat setting which is 4, 92, 100, 108, 116, and 120 a second these being marked as ¼ in red, 92, 100, 108, 116, and 120 in black, with beneath the 120 in red 60. At 6 o'clock is the subsidiary seconds dial. Gold spade hands, gold seconds hand, double ended beat hand with circular ends, blued-steel beat indicating hand.
Ebauche Marks: 1 127814
Frame: ½ plate layout. Under the combined fourth wheel and escape wheel cock, under the back plate and under the pallet cock 814. Under the balance cock 815.
Barrel and Mainspring: Going barrel I. diameter 17.0 mm., height 2.1 mm.
Mainspring: height 2.0 mm., thickness 0.23 mm.
Arbor: diameter 5.3 mm., snailed.
Hooking: Machined from solid.
Train: Gilded centre, third and fourth wheels with 6 crossings.
Jewelled: From the third onwards, the jewels rubbed in. The flicking lever pivots also jewelled. Ruby endstones for the balance. The lower third pivot not jewelled. A jewel hole in the cock that supports the beat arbor.
Escapement: Club tooth lever, straight line layout, short lever, double roller, impulse pin triangular. Steel escape wheel, the teeth chamfered.
A mixed escapement.
No. of teeth embraced 3 ½.
Balance and Spring: A split bimetallic balance, diameter 16.2 mm, thickness 1.0 mm. Blued-steel flat spiral spring with terminal curve and 17 turns.
Means of Regulation: An index mounted on the balance cock which registers against a divided scale with engraved 'AVANCE RETARD'
Train Counts and Beat Rate:
Great wheel (barrel) 69
Centre wheel 80 pinion 12
Third wheel 75 pinion 10
Fourth wheel 80 pinion 10
Escape wheel 15 pinion 8
Beat Rate: 18,000
Motion work: cannon pinion 12, minute wheel 36
minute pinion 10, hour wheel 40
The Metronome Work: is operated by two push buttons, one at the side and one which passes through the winding button. That through the winding button moves the castle wheel that operates the beat selection lever. This lever is controlled by a six step face cam which moves it so as to present a ratchet A to one of the six ratchet wheels selected. These ratchet wheels are in a stack mounted on the fourth arbor and have 4, 46, 50, 54, 58 and 60 teeth respectively. The ratchet A is on an arbor which also carries a flicking lever that operates a pallet on the arbor situated at the centre of the watch. The flicking lever is put out of operation whilst the beat is being selected and is also put in or out of operation by the side pusher. The arbor at the centre is biassed by a hairspring so as to return to it's zero position. The flicking lever is provided with a passing spring so that it can return so as to be ready to delivery the next blow to the pallet.
Winding System: Conventional positive set keyless winding.
Dimensions: Movement diameter 43.0 mm., height 10.0 mm.
Provenance: Formerly in the Ilbert collection. Ilbert purchased this from Bentley 10/11/1937.
- Not on display
Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.0959 (Ilbert Collection)
Previous owner/ex-collection number: P211 (Ilbert Ledger)