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 co-ordinate simultaneous astronomical or meteorological observations at multiple distant locations. Arrival in Adelaide Todd, along with his 19-year-old wife Alice Gillam Bell (after whom Alice Springs is named), arrived in Adelaide on 5 November 1855. They were accompanied by Todd's assistant, 24-year-old Edward Cracknell and his wife. (Cracknell subsequently became superintendent of telegraphs in New South Wales). On his arrival Todd found that his department was a very small one without a single telegraph line. His first commission was to erect a telegraph line between Adelaide city centre and Port Adelaide. Such a line had been mooted some years before, and impatient with the lack of action and seeing its commercial possibilities, James Macgeorge installed one privately, cleverly avoiding obstacles put in his way by the government, and had it operating in 1855. Todd's line, more direct and technically superior (and far more expensive) was opened in February 1856, and in June of that year he recommended that a line between Adelaide and Melbourne should be constructed. Todd personally rode over much of the country through which the line would have to pass. Todd and Samuel Walker McGowan, his counterpart in Victoria, proceeded to link the two colonies' telegraph systems near Mount Gambier