Atlantic telegraph cable laying, 1860s watercolour. Workers coiling Atlantic cable in one of the tanks of the hold of the SS Great Eastern during laying of the 1865 Atlantic telegraph cable. This ship, a former ocean liner and the largest ship of its time, was large and powerful enough for the task of laying a telegraph cable on the ocean floor. It laid 4200 kilometres across the Atlantic, and a further 48,000 kilometres of submarine telegraph cables between 1866 and 1878. The 1865 trans-Atlantic cable replaced the failed 1858 cable. This watercolour is from a series by British artist Robert Charles Dudley (1826-1909).