Twenty to the Mile: The Overland Telegraph Line: The greatest engineering feat of 19th century AustraliaThe greatest engineering problem facing Australia the tyranny of distance had a solution: the electric telegraph, and its champion was the sheep farming state of South Australia. In two years, Charles Todd, leading hundreds of men, constructed a telegraph line across the centre of the continent from Port Augusta to Port Darwin. At nearly 3,000 kilometres long and using 36,000 poles at 20 to the mile, it was a mammoth undertaking, but at last, in