Three-tier mahogany deck box with a brass insert holding the watch under a screwed brass bezel. The silver open-face case, which has gold joints and nibs, is hallmarked for London 1910-11 and is stamped with ‘8333’ and the sponsors mark ‘F.T.’ (Frederick Thoms). The chronometer has a gilt winding crown and brass push-piece for hand setting at one o’clock. The case back is engraved with: ‘↑’. The two-piece, white enamel, has black roman numerals, subsidiary seconds with Arabic ten-second numbers and is signed below XII: ‘KULLBERG / LONDON / 8333’ and ‘↑’ within the seconds dial. The chronometer has polished blued steel spade and poker hands with a fine pointer blued steel second hand with a counter poised tail. It has a gilt-brass half-plate keyless going barrel movement with three turned pillars fixed with polished and blued steel screws. The top of the half plate is engraved: ‘V. Kullberg, London / ↑ / No.8333’. It also has a ratchet-tooth lever escapement with free-sprung compensation balance and blued steel flat spiral balance spring, with overcoil. Jewelled to the third wheel.

The watch was purchased by the Admiralty and delivered to the Observatory in July 1916, costing £18 10s. The watch was in Navy service through until 1965 and remained in the MoD workshops until 1972 when it went on loan to the NMM.

Victor Kullberg (1824-90) was born in Visby on the Island of Gotland, Sweden. He was trained by the Swedish chronometer maker Victor Soderburg in Stockholm in 1840 and emigrated to London in 1851, having moved to his permanent address at 105 Liverpool Road, N1, by 1870. During his lifetime Kullberg gained many medals and awards for his chronometers and enjoyed a truly international reputation. As well as supplying many foreign governments, he regularly submitted chronometers for the Annual Trials at Greenwich Observatory, gaining first place in 1864 with a chronometer fitted with his newly invented ‘flat rim’ balance. His inventions included several designs of compensation balance and improvements to keyless winding for pocket watches. He also designed the automatic gas-governor for controlling the temperature of the chronometer testing ovens at the Observatory. More than 500 chronometers by Kullberg were supplied to the Royal Navy alone and he can be said to have been one of the 19th century’s finest chronometer makers. On Kullberg’s death in 1890 the firm was taken over by George and Peter Wennerstrom, themselves succeeded by Sanfrid Lundquist who had joined the firm in 1894 and who moved the firm to Cranford in Middlesex in 1938, trading under the name of Victor Kullberg until his death in 1947).