- Museum number
GOLD-PLATED CASED PIN-PALLET LEVER WATCH.
Ingersoll pocket watch.
17 jewel movement with pin-pallet lever escapement; keyless winding and hand-setting.
Silver coloured metal dial with gold baton hour markers; 3, 6, 9 and 12 batons having black line down centre.
Gold-plated single case with integral back and snap-on bezel; glass missing.
- Production date
Diameter: 42.30 millimetres (case)
Diameter: 36.80 millimetres (dial)
Thickness: 7.80 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Ingersoll
Switzerland, c. 1960
Watch with a pin pallet lever escapement.
Signature: On the dial "INGERSOLL 17 JEWELS SHOCK RESISTENT".
Case: Gold plated case two piece case with a snap on bezel.
The case numbered 1877 74. The glass is missing.
Dial and Hands: Silvered metal dial with gold batons as the hours. Those at 12, 3, 6, and 9 having a black line down the centre of the baton. Gold coloured baton hands.
Movement: The movement inscribed 'SWISS 17 JEWELS' and numbered E 3. The plates finished matt.
Ebauche Marks: EB 1197 N.(1)
Frame: Nickel silver plates, a bridge for the barrel and one for the train.
The barrel bridge is inscribed 'SWISS MADE 5 JEWELS'. Cocks for the pallets and balance.
Barrel and Mainspring:
Barrel: internal diameter 9.1 mm., height 2.0 mm.
Mainspring: height 1.8 mm, thickness 0.11 mm.
Barrel Arbor: diameter 2.95 mm., snailed.
Hooking: milled from the barrel wall.
Train: The brass wheels are not gilded, the centre wheel, third and fourth wheels with five crossings. The steel escape wheel with four.
Jewelling: Jewelled bearings for the balance. The jewels pressed in. Ruby endstones to the balance jewels.
Escapement: A straight line layout pin pallet lever escapement with short lever, double roller and D-shaped impulse jewel. Steel pins to the pallets. A steel escape wheel with four crossings.
An equidistant locking escapement.
No. of teeth embraced 3½.
Balance & Spring: A monometallic balance with nibs simulating screws. Balance diameter 9.95 mm, thickness 0.55 mm. A 'self compensating' flat spiral spring with 10 1/2 turns.
Means of Regulation: An index on the balance cock registers against a divided scale with + and - engraved on the balance cock table.
Train Counts and Beat Rate:
Great wheel (barrel) 70
Centre wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 60 pinion 8
Escape wheel 15 pinion 6
Beat rate 18,000
Motion work: cannon pinion 10
minute wheel 30, minute pinion 8
hour wheel 32
Keyless work: Rocking bar stem set keyless work.
Dimensions: Case diameter 42.2 mm., height 15.5? mm
Movement diam. 45 mm., h. 12 mm.
Provenance: Donated by the Heron Corporation in 1983.
(1) The ebauche makers Ebauches Bettlach S.A. They specialised in six basic calibres of pin lever watches 80% of the parts were common to all.
- Not on display
- Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number