DAVID KEYS No. 282: THE "GREENWICH TRIALS" WINNING CHRONOMETER FOR THE YEAR 1879, a two-day marine chronometer, signed on the silvered dial David Keys, 15 Craven St, Strand, London No.282, maker to the Admiralty, Roman hour chapters, up-and-down and subsidiary seconds dials, the latter inscribed Airy's Compensation with the Government Mark, blued steel hands, top-plate with the Government Mark insised, Earnshaw escapement, spring foot detent, cut bi-metallic balance with variant of Poole's compensation, palladium helical balance spring, brass bowl and gimbal, in three-tier rosewood box (slight damage) with boxwood stringing to front and top, the middle section with rectangular ivory plaque inscribed Keys No. 282 two days, brass external drop handles

Various Properties

细节

DAVID KEYS No. 282: THE "GREENWICH TRIALS" WINNING CHRONOMETER FOR THE YEAR 1879, a two-day marine chronometer, signed on the silvered dial David Keys, 15 Craven St, Strand, London No.282, maker to the Admiralty, Roman hour chapters, up-and-down and subsidiary seconds dials, the latter inscribed Airy's Compensation with the Government Mark, blued steel hands, top-plate with the Government Mark insised, Earnshaw escapement, spring foot detent, cut bi-metallic balance with variant of Poole's compensation, palladium helical balance spring, brass bowl and gimbal, in three-tier rosewood box (slight damage) with boxwood stringing to front and top, the middle section with rectangular ivory plaque inscribed Keys No. 282 two days, brass external drop handles
Dial; 102mm.diam.

来源

In April 1880 this chronometer was issued to the survey ship H.M.S. Flying Fish, commanded first by Commander Richard Hoskyn, R.N., who was scuceeded in 1883 by Commander John Fiot Maclear R.N. During the period 1880 to 1885 it was used in the surveys of Japan, Korea, and the China to Australia trade route. Subsequently it was issued to H.M. Ships Victor Emanuel, Alexandra, Colossus and Waterwitch. It ended its career in the Government service at the Atomic Research Establishment, Harwell; the purpose for which such a chronometer was used in connection with atomic science is not known, but could be the subject of further research. A number of documents commected both with the Greenwich Trials of 1879 and its subsequent history in the Naval Service are included with this lot.

拍品专文

This chronometer was placed "first" at the 1879 Greenwich Observatory Annual Chronometer Trials. In the specifications for these trials, under the heading "Construction of Escapement and Blanace" David Keys states - "Ordindary balance with slight alteration. Airy's Compensation". The bi-metallic rim has an affix at the joining point of the rim and the cross-arm which strongly resembles Poole's auxiliary, in addition it has two blued steel springs, one attached to each part of the Poole auxiliary which bridges the cut-gaps in the balance rim, each spring bearing against and controlling the movement of each bi-metallic sector at its outer end. The Airy's Compensation is no longer extent. The Greenwich Observatory Digest Book would appear to indicate that this was removed in 1885. The auxiliary fitted to this chronometer is not recorded in Gould, however a number of the chronometers exhibited by David Keys in the Greenwich Chronometer Trial are also described as "Ordinary balance, with slight attention" so it must be assumed that this is his own auxiliary.