Succeeded where earlier attempts had failed, the 1866 Transatlantic Communications Cable was a miracle of Victorian engineering that linked Britain and North America, making instantaneous communication possible. With a collection chosen by Dr Cassie Newland (BBC 2’s Coast) and Professor Mark Miodownik (BBC’s The Genius of Invention) to celebrate the cable’s 150th anniversary, ‘Victorians Decoded: Art and Telegraphy’ celebrate’s the achievements of the day at the City of London Corporation’s Guildhall Art Gallery, from 20 September 2016 to 22 January 2017. We spoke to Dr Newland to discover just how profound a change this mechanical marvel really was.

What did the 1866 cable correct about the previous attempts to link the continents?

Although the previous 1858 cable worked for a short period of time, it was badly made and had imperfect insulation, which resulted in poor conductivity and a low bandwidth. The 1866 cable was successful because it was better made from purer, well-drawn copper. It also had a thicker cross section which allowed for transmission speeds of up to 8 words per minute. This was outstanding at the time given that messages previously took weeks to send by ship. The 1865 cable was also recovered and repaired later that year, which provided a second transatlantic telegraph.

It seems particularly significant that the cable connected Great Britain and North America at such a crucial time for the British Empire – in particular the transition to self-ruled Dominions. What did the cable mean for the immediate future of the English-speaking world?

Attempts to lay the first transatlantic telegraph took place between 1857 and 1866 and the transition to self-ruled Dominions began in 1907, so the cables were not really in the picture. However they were of utmost importance to Anglo-American relations. The second ever telegram sent from the USA to Britain was from William H Seward (US Secretary of State 1861-69) to Queen Victoria bemoaning the fact the cable was not accomplished earlier and blaming the failure to connect the two countries sooner for slavery and the American Civil War!

How long did the process of laying the cable take and what sort of feats of logistics did it involve?

It took four attempts over nine years for the cable to be successfully laid. At the time no one had ever made cables in such great lengths so a transatlantic telegraph was a great challenge, both mechanically and electrically. The failed cables were hugely costly and represented a very steep learning curve, if not a leap into the unknown. The successful 1866 cable was so heavy and required so much space that the biggest ship in the world at the time, Brunel’s SS Great Eastern, was required to carry it.

What were the end points of the cable? Did they run to a central hub and who was responsible for them?

On the Irish side the cable came ashore on Valentia Island, one of the westernmost points of Ireland. From there the cable was connected to the existing landline system. Messages were then forwarded to any British town or city, or even over the English Channel to anywhere in the connected world. The other end of the cable landed in Trinity Bay, Newfoundland (Canada) where the sleepy little town of Heart’s Content suddenly found itself connected to New York in one direction and the whole of the ‘Old World’ in the other.

What was the process for the average (wealthy) citizen wanting to use the cable?

They would most likely send a servant to their nearest telegraph office. The message would be written onto paper and a telegraph clerk would calculate the price of the message before passing it onto the telegraph operator’s room. If the message was urgent it could be sent at once (for a fee), but more often than not it would be placed on a small pile in front of an operator waiting to be sent. The message would then be tapped out in Morse code and sent down the line.

At the receiving end of the transatlantic telegraph cable another clerk would write down the content and destination of the message. This would then be given to a telegraph boy who would have gone running through the streets to deliver it. It was actually quite a lengthy process and several pairs of eyes often read messages before they reached their final recipients.

The role of ciphers and codes in the exhibition seems interesting. How were these used? Could the cable be tapped or was it more of a case of deterring gossipy telegraph operators?

Codes and ciphers were incredibly important because so many pairs of eyes saw each message on the way through the system. The government and military were heavy users of the telegraph and frequently had to send sensitive information encoded. Likewise, businesses could not openly display their intended actions for fear of the information being sold to competitors, or worse, to traders who could use the information to manipulate markets and share prices. Domestic customers, especially in small gossipy villages, were particularly put off by having their private dealings made public. The kind of news that needs to be sent in a hurry is often sensational!

The cable seems like one of those sources of engineering wonder to the Victorian world (warranting a mention in Twenty Thousand Leagues Under the Sea), what was the reaction to it at the time?

Public reactions were a combination of awe, celebration and wonderment. The moon landings are the modern-day equivalent of the transatlantic telegraph in terms of significance. There were banquets, speeches, interviews and special ‘collectors’ editions’ of newspapers. The scientists and engineers behind its success were given Honours and Knighthoods. Those involved published their diaries which became bestsellers. The souvenirs market also went mad. Tiffany’s even bought some spare cable and made a fortune selling slices of it mounted on walking sticks, watch fobs and jewellery. Everybody wanted to be part of what became known as ‘cable mania’.

Charles Wheatstone seems a relatively underappreciated figure. Why did the Victorian era produce so many discipline-straddling tinkerers and what makes him stand out?

I am always a little surprised by how little-known Charles Wheatstone is. He was a notoriously nervous (and poor) public speaker, though very friendly and animated in private. He used to get his good friend Michael Faraday to deliver his papers for him. Wheatstone was particularly good at producing practical outputs for new theoretical concepts, and he built machines, experiments and devices which proved or demonstrated the ideas of others. He was also great at designing practical applications for new phenomena. It is his machines, such as his telegraph, stereoscope and Wheatstone bridge that live on in memory, rather than his name.

This period in history produced so many discipline-straddling figures because disciplines were much broader then than they are today. For example, Wheatstone was appointed as a Professor of Natural Philosophy, a title which included many subjects including biology, chemistry, physics, meteorology, astronomy and engineering. It was the breakthroughs made by the polymaths of the 19th century that led to the disciplinary specialisms as we know them.

‘Victorians Decoded: Art and Telegraphy’ can be seen at the City of London Corporation’s Guildhall Art Gallery, from 20 September 2016 to 22 January 2017. For more amazing innovations, pick up the new issue of All About History or subscribe now and save 25% off the cover price.