Thomas Mercer Ltd., St. Albans, England, Movement No. 19177, 200 x 140 x 200 mm, circa 1950

A remarkable deck chronometer with 24-hour dial, 56h power reserve indicator and electrical contact device - timed to sideral time
Case: mahogany, aluminium bowl with protection cap. Dial: silvered, aperture for second wheel with contact. Movm.: brass movement, spring detent escapement according to Thomas Earnshaw, hack feature, to us so far unknown special Mercer auxiliary comp. balance with affix.