Charles Frodsham, 84 Strand London, No. 9768 AD Fmsz, Movement No. 9768 AD Fmsz, Case No. 28099, 49 mm, 90 g, circa 1856

An exquisite pocket chronometer with spring detent escapement and "DUO IN UNO" balance spring
Case: 18k gold, consular case, florally engraved, case maker's punch mark "RO" (Richard James Oliver, London). Dial: enamel, radial Roman hours, auxiliary seconds, 24h power reserve indicator, signed, blued spade hands. Movm.: 2/3 plate movement, chatoned, frosted, gilt, signed, keywind, chain/fusee, gold screw compensation balance, freesprung, blued "DUO IN UNO" balance spring, chatoned diamond endstone on balance.