Inscribed plate for specimens of submarine telegraph cables, made by Thomas Moring, Holborn, London, England, 1862.

The core for all seven of these cables was made by the Gutta-Percha Company. The 1851 Dover to Calais cable was laid from HMS Blazer under the direction of Thomas Crampton and Charlton Wollaston, the engineers of the Submarine Telegraph Company. In three weeks 24 miles of cable had been manufactured, which should have been sufficient for the 21 mile distance between Dover and Calais but, due to how it was laid, an additional mile of cable had to be made and added to the rest. The 1853 Dover to Ostend (Belgium) cable was manufactured by R S Newall and Company. It took 100 days and, before being loaded on to a cable ship, lay in Newall's yard in a coil that was 4 feet 8 inches high, and 51 feet around the outside. The 1854 La Spézia to Corsica cable was 75 miles long and was part of a larger project to connect France, Corsica, Sardinia and Algeria. The Cromer to Hanover cable was laid by the Belgian arm of the Submarine Telegraph Cable Company, as was the Cromer to Denmark cable of 1859.