0540 ← Prev Lot ↑ Catalogue Next Lot →

A Mercer's survey chronometer

two-day duration with Arnold type spring detent escapement and fusée and chain movement, silvered and engraved dial marked 'Thomas Mercer Maker to the Admiralty, The Indian Colonial & USA Governments, London & St. Albans, 12781', blued steel hands. Hours are numbered 0-23 with Arabic numerals. Bayonet bezel with shuttered winding hole in the glass. Dial is cut away to show a 59 tooth contact lifting wheel mounted on the seconds arbor and a contact blade which is lifted each second except for the 59th in each minute to enable an audible signal in earphones each second with the silence being a warning of the approach of the full minute. Mounted in blackened brass cylindrical case with external battery and microphone contacts and stop/start lever and encased in heavy leather carrying case with strap, and pouch for safety ratchet winding key. Originally purchased by NZ Government in 1925 (c.f. Mercer: Mercer Chronometers p.210.)

Realised: $1,000