Bezel-wound silver-cased club-tooth lever wrist-watch with brown leather strap

Description — British Museum

Wrist-watch with brown leather strap. Club-tooth lever escapement; bezel wind and hand setting. White painted dial with luminous Arabic hour numerals and subsidiary seconds. Silver case with Glasgow import mark.

Curator's comments — British Museum

Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript) ANONYMOUS Switzerland, c. 1914 Silver cased wrist watch, bezel wound and hand set with a club tooth lever escapement. Signature: The movement marked 'BREVET' with the Helvetia cross. The name on the dial removed but 'PT APPL FOR' is still there. Case: A three part silver case with the import marks for Glasgow for 1914 and the case makers mark F.W and numbered 188493. The case band is also marked 925. Between the lugs at 6 o'clock is a catch which in omne position allows winding and in the other hand setting. Dial & Hands: An enamel dial with Arabic numerals filled with luminous paint. A sunk subsidiary seconds dial. Luminous filled skeleton hands of blued steel. The seconds hand of blued steel. Movement: Ebauche Marks: The winding ring retaining plate stamped 577. The front plate stamped HP 188577 and a cross within a circle, AD and 7. Frame: A gilt brass frame. A bridge for the barrel, one for the train, cocks for the escape wheel, pallets and balance. Under and on the barrel bridge is 577 under the train bridge is 7 and 77, the 5 seems to have been filed away when the lifting notch was put in. Barrel and Mainspring: The going barrel marked inside 77. Barrel: I diameter 10.5 mm, height 1.35 mm. Mainspring: height 1.25 mm, thickness 0.15 mm. Barrel Arbor: diameter 3.5 mm, snailed. Hooking: A tongue pressed in 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 rubbed 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. A mixed escapement. No. of teeth embraced 3½. Balance & Spring: a split bimetallic balance with brass compensation screws and two platinum timing screws. Balance diameter 9.9 mm, thickness 0.65 mm. A blued-steel flat spiral spring with 17 turns and a terminal curve. 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 80 (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 with a pinion mounted on the stem to mesh with the winding ring. When the case catch is moved over it acts on the side set lever. Dimensions: Case: diameter 32.7 mm., height 11.3 mm., over the glass. Movement: diameter 26.5 mm, height 7.2 mm. Provenance: Purchased in 1984 with the aid of funds made available by Stanley H. Burton. Note: On releasing the movement dog screws the bezel and the movement drop out as one. On removing a side set screw in the bezel the movement can be rotated so as to release the two lugs on the movement winding ring from bayonet catches in the bezel rim. Removing the dial then reveals the plate that retains the winding ring. After removing this winding ring standard procedure can be followed for further dismantling.