The first transatlantic telegraph cable is completed and fails

Background. The Atlantic Telegraph Company, formed in October 1856, aimed to lay a cable across the Atlantic. Cyrus West Field secured financing and government backing. The project utilized a shallow submarine plateau between Ireland and Newfoundland. Vessels HMS Agamemnon and USS Niagara were borrowed for the task. Internal conflicts between engineers Thomson and Whitehouse complicated the operation, with Whitehouse often evading voyages.

Laying and Completion. The cable was started in August 1857 but required a new mechanism tested in 1858. Ships set out in July 1858, finishing the middle splice on July 29. Agamemnon arrived at Valentia Island on August 5, landing the shore end at Knightstown. The first communications occurred on August 16, 1858, though line speed was poor, taking two minutes per character.

Failure and Aftermath. The cable failed in September 1858 due to progressive insulation deterioration, particularly in the first hundred miles from Ireland. Operation was terminated on October 20, 1858. Field returned to a triumphant homecoming in August 1858, celebrated as the parent of the scheme. The cable was not reconnected until 1866, when improved methods allowed faster transmission.