Sadly, the jubilation was premature. Within four weeks, the gutta percha insulation (an organic latex used before plastics were developed) on the copper core had failed, breaking off the historic connection. But although it was to be another 10 years before a commercially viable link was established, such a feat would not have been possible without the many lessons learned in the 1850s.

Given the infancy of electrical engineering and the inadequacy of the materials available, mistakes were inevitable. But one blunder stands alone from the crowd as having been rather less excusable than the rest. While it is relatively easy to string telegraph wires on poles across land, laying a line on the seabed is considerably more challenging. The first undersea cable was laid from Dover to Calais in 1850, and was worn away by rocks after a day.

It was clear, then, that cables must be wound about with iron wire. But a mile of such armoured cable weighs a ton, and its bulk makes handling difficult. When the first attempt was made to lay such a cable between Ireland and Newfoundland, it was manufactured in two halves by different companies. The sections were then carried into the Atlantic on separate ships, to be spliced together before laying commenced. But when, in mid-ocean, the crews attempted to join their cable ends, they discovered that the manufacturers had twisted the sections in opposite directions.

Only by clamping and weighting the ends did they eventually manage to splice the halves in such a way that they wouldn’t unravel each other. The Illustrated Times of August 1, 1857, praised their remedy for a “rather serious oversight”.

In the event, however, their ingenuity was wasted, for that first cable snapped long before laying was complete.