Foilhummerum Bay, Valentia, from Cromwell Fort: The Caroline Laying the Earthwire on July 21st, 1865, 1865, Watercolor over graphite with touches of gouache, Sheet: 6 5/16 ? 9 7/16 in. (16 ? 24 cm), Drawings, Robert Charles Dudley (British, 1826?1909), One of the 19th century's great technological achievements was to lay a telegraphic cable beneath the Atlantic, allowing messages to speed back and forth between North America and Europe in minutes, rather than ten or twelve days by steamer