Small chrome-plated cased club-tooth lever ladies wrist-watch with enamel dial and brown leather strap

Description — British Museum

Wrist-watch. Movement with club-tooth lever escapement; signed on ratchet-wheel. White enamel dial with luminous-painted Arabic hour numerals; the 12 in red; subsidiary seconds. Pierced blued-steel hands in-filled with luminous paint. Chromium-plated case with snap-on bezel. Brown leather wrist-strap.

Curator's comments — British Museum

Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript) Made by Roskopf Switzerland, c. 1940 Wrist watch with club tooth lever escapement. Signature: On the dial 'ROSKOPF PATENT', the trade mark in red and 'SWISS MADE'. On the barrel ratchet wheel 'ROSKOPF' and two stars. Case: A stainless steel three piece case the back marked with a circle within a triangle and 'EDELSTAHL'. On the inside of the back is 1 and 3197. Dial & Hands: Unexpectedly the dial is of enamel. A sunk subsidiary seconds dial. Arabic skeleton numerals, the 12 in red all of the others in black and filled with luminous paint. Blued-steel skeleton hands also filled luminous and a blued-steel seconds hand. Movement: Ebauche Marks: 36 87 Frame: A nickel silver movement. A bridge for the barrel and centre and another for the third and fourth wheels. Cocks for the escape wheel, the pallets and the balance. The front plate spotted and the movement damascened on the back. Scratched under the train and the barrel bridges 36 87. Scratched under the cocks 36. Barrel and Mainspring: Scratched inside the going barrel and the recessed cover 36. Barrel: I diameter 7.7 mm., height 2.1 mm. Mainspring: height 2.1 mm., thickness 0.10 mm. Barrel Arbor: diameter 2.4 mm., snailed. Hooking: Milled from the barrel wall. Train: All the brass wheels gilded, the centre, 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 monometallic balance with brass screws. Balance diameter 6.7 mm., thickness 0.55 mm. A 'self compensating' flat spiral spring with 10 turns, badly distorted. 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 68 (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 Winding System: Conventional positive stem set keyless work. Dimensions: Case diameter 21.3 mm., height 8.8 mm., over the glass. Movement: Diameter 19.3 mm., height 5.1 mm. Provenance: Purchased in 1987 with the aid of funds from the Dingwall Bequest.