Timekeeping, Domestic clocks and watches, Astronomical regulators and precision clocks

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Electrical master clock


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Object ID ZAA0531
Description From 1852 to 1893, this master clock was the heart of Britain's time system. Its time was sent by telegraph wires to London, Edinburgh, Glasgow, Dublin, Belfast and many other cities. By 1866, time signals were sent from this clock to Harvard University in Cambridge, Massachusetts via the new transatlantic submarine cable. In terms of the distribution of accurate time into everyday life, this is one of the most important clocks ever made. A slave dial connected to this clock, at the gates of the Royal Observatory, was the first clock ever to show Greenwich Mean Time (GMT) directly to the public. In 1851 at the famous Great Exhibition held in Hyde Park, London, one of the world's first ever 'master-and-slave' clock systems was installed by Charles Shepherd of Leadenhall Street. It consisted of a central 'master clock' sending regular electrical impulses to a number of ancillary 'slave' dials. George Airy, the seventh Astronomer Royal, saw the potential advantages of such a system and ordered one to be made for the Royal Observatory in Greenwich. Airy's report to the Observatory's Board of Visitors in 1853 explains the function of the Shepherd master clock, or 'Normal Clock': ‘This clock keeps in motion a sympathetic galvanic clock in the Chronometer-room, which, therefore, is sensibly correct; and thus the chronometers are compared with a clock which requires no numerical correction. [...] The same Normal Clock maintains in sympathetic movement the large clock at the entrance-gate, two other clocks in the Observatory, and a clock at the London Bridge Terminus of the South-Eastern Railway. [...] It sends galvanic signals every day along all the principal railways diverging from London. It drops the Greenwich Ball and the Ball on the Offices of the Eastern Telegraph Company in the Strand [...] All these various effects are produced without sensible error of time; and I cannot but feel a satisfaction in thinking that the Royal Observatory is thus quietly contributing to the punctuality of business through a large portion of this busy country.’ Charles Shepherd was the son of another noted watchmaker, also called Charles. In 1849 Charles Shepherd Junior (described in the 1851 census as an ‘engineer’), who was just 19 years old, submitted his first patent for ‘Improvements in Working clocks and other timekeepers Telegraphs and Machinery by Electricity’. His developments of this principle were to have profound effects on the history of horology. The electric clock system he exhibited at the Great Exhibition in 1851 and which was supplied to Greenwich Observatory the following year, was to be the basis of Britain’s time-distribution system for the following 70 years. In 1853 Charles Junior was appointed ‘1st Class assistant to the Electric Telegraph Establishment’ working for the East India Company and responsible for overseeing the establishment of a telegraph network for the Indian Government. After an initially good start, Charles Junior’s service became increasingly unsatisfactory and he was dismissed from his post in 1856, presumably returning to England directly, though no certain evidence has been found as yet.
Date made circa 1852

Artist/Maker Shepherd, Charles
Place made London
Credit National Maritime Museum, Greenwich, London
Materials metal; wood; glass
Measurements Overall: 1900 x 590 x 260 mm
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