Silver-cased rolex club-tooth lever wrist-watch with modern coloured nylon strap

Description — British Museum

Wrist-watch. Movement with club-tooth lever escapement. White enamel dial with Arabic hour numerals within minute circle and sunk subsidiary seconds. Blued-steel hands. Silver case with hinged back and bezel. Modern red, white and blue nylon wrist-strap.

Curator's comments — British Museum

Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript) Made by Rolex Watch Co. Switzerland, c. 1916 Silver cased wrist watch with club tooth lever escapement. Signature: On the case 'ROLEX SWISS' and on the barrel ratchet wheel 'ROLEX 15 JEWELS'. Case: Three piece silver case a hinged bezel and back. The case back marked 'ROLEX SWISS' with London import marks for 1916. The case back which is badly dented is numbered 746969 and 4. Dial & Hands: Skeleton Arabic numerals and a sunk subsidiary seconds dial. A moon minute hand, not original, a skeleton hour hand, a polar type seconds hand. All hands in blued-steel. Movement Ebauche Marks: 'REBBERG DEPOSE' 5184.(1) A trade mark on the front plate under the barrel bridge like a J running into a 3. Frame: A nickel silver movement, a bridge for the barrel, another for the train. A bridge for the pallets and a cock for the balance. Barrel and Mainspring: A recessed cover to the going barrel. Barrel: internal diameter 10.0 mm., height 1.40 mm. Mainspring: height 1.30 mm, thickness 0.13 mm. Barrel Arbor: diameter 3.3 mm, snailed. Hooking: A round hook. Train: All the brass wheels gilded but on one side only, 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 rubbed in. Ruby endstones to the balance jewels. Escapement: A straight line layout club tooth lever escapement with short lever, double roller and the impulse pin elliptical in section. The exposed pallet stones have flat acting faces. A steel escape wheel with four crossings. The pallet staff screwed in. An equidistant locking escapement. No. of teeth embraced 3½. Balance & Spring: a bimetallic balance but not split and with brass screws. Balance diameter 9.2 mm, thickness 0.7 mm. A bright-steel flat spiral spring with 13 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 95 (barrel) 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: Conventional positive set keyless work. Dimensions: Case: Diameter 31.0 mm., height 10.4 mm. Movement: diameter 25.0 mm., height 6.3 mm. Provenance: Purchased in 1987 with the aid of funds from the Dingwall Bequest. Note: (1) See James L. Dowling and Jeffrey P. Hess 'The Best of Time ROLEX WRISTWATCHES'. Pa - u: S.A. 1996.