STANLEY'S POCKET CHRONOMETER
A rare silver Open Faced Pocket Chronometer with special balance and free sprung special balance spring and 56-hour power reserve indication. Dent, 33 Cockspur Street, London, No. 28318, 1875. Signed and numbered frosted gilt half-plate movement with chain fusee and maintaining power, turned pillars, Earnshaw type spring detent escapement, cut bimetallic compensation balance with Mercer's type-H auxiliary, blued steel duo-in-uno balance spring and diamond endstone, jewels with screwed chatons, signed and numbered white enamel dial also inscribed with Royal warrants, Roman numerals, subsidiary seconds, up-and-down indication, blued steel hands, silver cuvette, numbered polished case with London marks for 1875, casemaker's initials JTW, diameter 67mm.
John Hammersly is recorded in 1875 at 54 Spencer Street, Clerkenwell, London as a chronometer watch maker; he also developed the 'Tria in Uno' balance (Tony Mercer, Chronometer Makers of the World. N.A.G. Press, Colchester 1991 page156. M.F.Dent is recorded as supplying one chronometer to H.M.Stanley in 1890 for his Congo Expedition (IBID page 130). On July 5th, 1890, Stanley wrote to M.F. Dent: 'The Chronometers supplied by you, and which were taken across Africa in my last Expedition, proved a very great service to me and were in every way thoroughly satisfactory and reliable' (Vaudrey Mercer, The Life and Letters of Edward John Dent, The Antiquarian Horological Society, 1977, p.540).