Club-tooth lever wrist-watch in a gold case with black leather strap

Description — British Museum

Club-tooth lever wrist-watch in a gold case with black leather strap. Wrist-watch. Half-plate movement. Club-tooth lever escapement. White painted-metal dial with minute circle surrounding Arabic hour numerals; the 12 in red; subsidiary seconds. Blued-steel hands. Plain gold case with hinged back and snap-on glazed bezel. Black leather wrist-strap of later date.

Curator's comments — British Museum

Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript) Made by Waltham Watch Co. U.S.A., c. 1907 Gold cased wrist watch with club tooth lever escapement. Signature: On the dial 'Waltham USA'. On the train bridge 'Waltham 17 JEWELS ADJ. TEMP'. On the barrel bridge 'Ruby USA 27'… 766836. Case: A 9ct. gold open face case hall marked Birmingham 1928. The case also marked in cameo A. L. D. and DENNISON WATCH CASE Co. Ltd. Also numbered 406015 and 6/0 NEW. The bezel and the band numbered 6015 with the band also with 9 375 in cameo. Dial & Hands: A painted brass dial with black Arabic numerals with a red 12. A sunk subsidiary seconds dial. The blued-steel hour hand is of spade design, the minute hand is missing. The seconds hand is blued-steel. Movement: Ebauche Marks: 766836. Frame: A nickel silver movement. A bridge for the barrel centre and third wheel, under this bridge is 766836. Another bridge for the fourth and the escape wheels. Cocks for the pallets and the balance, under the balance cock is 6837, presumably a mistake. Barrel and Mainspring: A plain arbor passes through the centre of the barrel, this is squared into the barrel ratchet wheel and into the barrel bottom. The great wheel carries the barrel arbor. Barrel: internal diameter 10.0 mm, height 1.55 mm. Mainspring: height 1.45 mm, thickness 0.11 mm. Barrel Arbor: diameter 3.15 mm, snailed. Hooking: Round. Train: All the brass wheels gilded, the centre wheel, third and fourth wheels with five crossings. The steel escape wheel with four. Jewelling: Jewelled bearings from the centre wheel onwards, all the jewels in gold chatons. Those for the centre in the bridge and in the balance cock are in screwed settings. 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 convex impulse faces. A mixed escapement. No. of teeth embraced 3½. Balance & Spring: a split bimetallic balance with gold compensation and quarter screws. Balance diameter 10.45 mm., thickness 0.75 mm. A blued-steel flat spiral spring with 12 ¾ turns and a terminal curve. Means of Regulation: An index on the balance cock registers against a divided scale with 'FS' 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 70 pinion 8 Escape wheel: 15 pinion 7 Beat rate: 18,000 Motion work: cannon pinion 10 minute wheel 30, minute pinion 8 hour wheel 32 Winding System: Negative set keyless work with a lever to put the keyless work into the wind position when the movement is out of the case. Dimensions: Case: Diameter 28.5 mm., height 7.8 mm.(over the glass) Movement: Diameter 24.7 mm., height 5.7 mm. Provenance: Purchased in 1987 with the aid of funds from the Dingwall Bequest.