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Sir Charles Todd KCMG, FRS , MA, FRAS, FRMS, FIEE (7 July 1826 – 29 January 1910) worked at the Royal Greenwich Observatory 1841-1847 and the Cambridge University observatory from 1847-1854. He then worked on telegraphy and undersea cables until engaged by the government of South Australia as astronomical and meteorological observer, and head of the electric telegraph department. ==Early life and career== Todd was the son of grocer Griffith Todd〔H. P. Hollis, 'Todd, Sir Charles (1826–1910)', rev. K. T. Livingston, Oxford Dictionary of National Biography, Oxford University Press, 2004〕 and Mary Parker;〔Source Citation: Place: Islington, London, Eng; Collection: Dr. William's Library; Nonconformist Registers; Date Range: 1815 - 1832; Film Number: 815926〕 he was born at Islington, London, the third of five children. Shortly after Charles's birth the family moved to Greenwich, where his father set up as a wine and tea merchant. Charles was educated and spent most of his life in Greenwich before moving to Australia. In December 1841 he entered the service of the Royal Observatory, Greenwich, under Sir George Biddell Airy. He was fortunate that his school leaving coincided with the Astronomer Royal being granted special funding to employ an additional four young men as computers to analyse, calibrate and publish a backlog of 80 years of data. While at the Royal Observatory he was one of the earliest observers of the planet Neptune in 1846. He was promoted to Assistant Astronomer at the Cambridge Observatory in November 1847,and officially confirmed in the position the following February. While here he used the recently built Northumberland telescope, and he was the first person to take daguerreotype photographs of the moon through it. While at Cambridge he also gained experience in using the telegraph. In May 1854, shortly before his appointment to South Australia, he was placed in charge of the newly formed Galvanic Department at Greenwich. This was to be an extension of work he had done using the electric telegraph at Cambridge. In February 1855, he accepted the position of Astronomical and Meteorological Observer, and Head of Electric Telegraph Department in South Australia. 〔(【引用サイトリンク】title=Letter of appointment, Sir Charles Todd, 1826-1910 )〕 Meteorology was work done by astronomers; it was the recording of data so that the climate in different regions was known. The Royal Observatory was run by the Admiralty. Accurate calculation of time was an important part of the Royal Observatory’s responsibilities. Greenwich Time had long been used at sea; ship’s navigators relied on its accuracy to calculate their longitude. During Todd's time at the Greenwich and Cambridge observatories the railway system was expanding, and the electric telegraph was invented. Faster railway travel, and the need for timetables and signalling systems, necessitated a change from using solar time in different regions to a standardised railway or London time (later Greenwich Mean Time). The electric telegraph made it possible to transmit information, including time, at practically instantaneous speed. So the development of the electric telegraph was driven by the requirements of the railways. At about the time Charles Todd moved to Cambridge, George Airy arranged the connection of the Greenwich Observatory to the nearby telegraph line that was being built by the South Eastern Railway. This gave the observatories access to the electric telegraph, and the railway company access to accurate time. Once the electric telegraph was in place, the observatory was able to control clocks and time balls at any place there was telegraphic connection. It was also possible to perform a number of astronomical and other experiments. While at Cambridge, Charles Todd was a member of a team that determined the exact degrees of longitude at Greenwich and Cambridge using the electric telegraph. Todd's work as head of the Galvanic Department at Greenwich was to be an extension of his work using the electric telegraph. In particular, it was to transmit electric time signals to slave clocks and time balls, and to coordinate simultaneous astronomical or meteorological observations at multiple distant locations. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Charles Todd (pioneer)」の詳細全文を読む スポンサード リンク
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