Lead weight from the first transatlantic telegraph cable, c 1857-1858.
© Science Museum / Science & Society Picture Library
Submarine cables were weighted to help them withstand damage from ships, currents and aquatic life. This lead weight (marked 'REID') was used to anchor the the first transatlantic telegraph cable, laid from Newfoundland to Valentia in Ireland, in 1857-1858. However, despite these efforts, the telegraph was only in use for three weeks before breaking. It was not until 1866 that a permanent cable acros the Atlantic was established, reducing overseas communication times from the length of a sea voyage to just a few minutes.