A mid 20th Century Swiss two day spring detent marine chronometer in a brass bound mahogany box. Full plate gilt keywind fusee movement, four turned pillars secured by polished steel screws. Fusee and barrel under a separate bridge bearing Nardin’s stamp and serial number. Harrison’s maintaining power, gilt barrel ratchet wheel and click. Gilt cock with diamond endstone, polished steel micrometer regulator. Compensation balance, the two arms placed centrally in the rims, four circular weights and two timing nuts. Blue steel overcoil hairspring. Earnshaw spring detent escapement, escape wheel under a separate bridge, pivots with endstones. Signed and numbered silvered brass dial, subsidiaries for seconds and power reserve indication, Roman numerals, blue steel hands. Turned brass bowl, sprung rotating shutter to the winding hole, screw brass bezel with flat glass. Brass gimbals and locking mechanism. Three tier brass bound mahogany box, folding brass handles, rectangular signed plate above circular numbered disc.