wrist-watch
- Museum number
- 1983,1012.159
- Description
-
ALLOY-CASED CLUB-TOOTH LEVER WRIST-WATCH.
Wrist-watch.
Movement with club-tooth lever escapement; 15 jewelled Swiss made.
Silvered metal dial with luminous painted Arabic hour numerals; subsidiary seconds.
Luminous painted hands.
Alloy case with screw-on back.
Keyless winding and hand setting.
- Dimensions
-
Diameter: 28.20 millimetres
- $Inscriptions
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-
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- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Ingersoll
Switzerland, c. 1965.
Wrist watch with a club tooth lever escapement.
Signature: On the dial 'INGERSOLL WATERPROOF SWISS MADE'.
Case: A shaped alloy case with patent marks and the number 531392 both on the case end and inside the screw on back. Spring bars for lugs. Also inside the case back is 'BREVET' and the Helvetia cross, 'FOND ACIER INOXYDABLE, SWISS MADE, BRIT PAT 385 509', and within a rectangular cartouche a trade mark 'F B' with beneath a representation of a key.
Dust Cap: A dust ring surrounds the edge of the movement.
Dial & Hands: A silvered dial with a sunk centre and a sunk subsidiary seconds dial. Luminised Arabic numerals and skeletonised and luminised hands. The seconds hand of blued- steel.
The dial is secured by two dog screws.
Movement:
Ebauche Marks. AS 984.(1)
On the train bridge is 'INGERSOLL' and on the barrel bridge is '15 JEWELS 3 ADJ SWISS MADE'.
Frame: A nickel plated brass frame with a spotted finish.
A bridge for the barrel and winding work, one for the train and cocks for the escape wheel, pallets and balance.
Barrel and Mainspring: A recessed cover to the going barrel.
Barrel: I diameter 9.1 mm., height 1.2 mm.
Mainspring: height 1.2 mm, thickness 0.10 mm.
Barrel Arbor: diameter 3.0 mm., snailed.
Hooking: milled from the barrel wall.
Train: All the brass wheels are gilded, the centre wheel, third and fourth wheels with five crossings. The steel escape wheel with four.
Jewelling: Jewelled bearings from the third wheel onwards. All the jewels pressed in. Ruby endstones to the balance jewels.
Escapement: A straight line layout, club tooth lever escapement with short lever, double roller and D-shaped impulse pin. The exposed pallet stones have flat acting faces. A steel escape wheel with four crossings.
An equidistant locking escapement.
No. of teeth embraced 3½.
Balance & Spring: an uncut monometallic balance with brass screws. Balance diameter 9.63 mm, thickness 0.70 mm. A blued- steel flat spiral spring with 10 turns.
Means of Regulation: An index on the balance cock registers against a divided scale with 'F S' and 'A R' 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 pinion 6
Beat rate 18,000
Motion work: cannon pinion 10
minute wheel 30, minute pinion 8
hour wheel 32
Winding System: Conventional positive stem set keyless work.
Dimensions: Case diameter 26 mm., height 11 mm., over the glass.
Movement: diameter 23.7 mm., height 5.7 mm.
Provenance: Donated in 1983 by The Heron Corporation Ltd.
Note:
(1) Schild S.A.
- Location
- Not on display
- Condition
- Latest: 3 (Mar 1995)
- Acquisition date
- 1983
- Department
- Britain, Europe and Prehistory
- Registration number
- 1983,1012.159