The development of the electric telegraph revolutionised our ability to communicate over longer distances. It aided the military and commerce and made the world a much smaller place by eventually enabling communications across bodies of water. However, much of the electrical telegraph’s early development focused around its need in Britain’s fledgling steam railway network.

180 years ago on 25th July 1837, William Fothergill Cooke and Charles Wheatston successfully demonstrated the electric telegraph for the first time, between Euston and Camden Town, in front of the directors of the London and Birmingham Railway.

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Connecting Euston and Camden Town

On  June 12, 1837 Cooke and Wheatstone were awarded a patent for an electric telegraph, which was to be the last signed by King William IV before his death 10 days later. The previous month, the pair had entered into a business accord which would become the Electric Telegraph Company a number of years later; the company was a direct ancestor to today’s BT.

The demo took place between Euston (where Wheatstone was located) and Camden (where Cooke was). Their instrument could potentially fill a vital need at Euston Square station (via DistantWriting.co.uk, which has a brilliant in-depth piece on the Cooke/Wheatstone relationship).

This telegraph could be used to signal the starting and stopping of a cable system at Euston Square, which enabled the trains to be pulled up the steep incline into Camden Town station a mile away. It was there that the locomotives were attached and the train sent north to Birmingham.

1837 Cooke and Wheatstone telegraph patent BT Archives

Suitably impressed, the company’s engineer Robert Stephenson – who’d become a central figure in the early proliferation of the telegraph - paid for the installation of a circuit out of the railway’s coffers.

The first instrument was a five-needle telegraph, which featured 20 letters, making it possible for all literate people to operate (albeit with some spelling concessions). Using an electric current, the needles could be used to point to different letters on the dial, enabling the two stations to communicate with each other

The installation of the world’s first commercial electric telegraph line that August would mark the beginning of the close relationship between the railways and the telegraph system. However, that initial success was short-lived. The railway company considered it unnecessarily complex and it was discontinued in January 1838. Plans to expand to Manchester and Liverpool were also shelved.

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Introducing the world’s first permanent telegraph

It then fell on the Great Western Railway to pick up from its rivals and 18 months later, in July 1839, a permanent electric telegraph system was completed between London Paddington and West Drayton. According to the historian Stephen Roberts, this was a four-needle system, which improved upon the original five-needle design. More instruments were deployed at Ealing, Hanwell and the railway’s Bull Bridge depot, but interest waned here too.

Perhaps the greatest breakthrough came through installations along the three-mile stretch of the London & Blackwall Railway during July of 1840. Initially installed at all five stations on the line, these instruments featured one-needle designs used for train control and also for messaging, with letters signified according to the number of times the needle moved back and forth.

In an 1842 book called Railways of Great Britain and Ireland, Francis Winshaw wrote of the London & Blackwall Railway:

"We must not omit to mention briefly the beautiful apparatus of Messrs Wheatstone and Cooke, by which instantaneous communication is effected between the terminal stations, or between any one station and any other on the line.

“Without this, one of the most splendid inventions of modern times, the working of the Blackwall Railway according to the present system would have been rendered rather hazardous."

Cooke and Wheatstone BT Archives

Eventually there were 30 telegraph instruments installed, with policemen attending to them at some points along the route. This would prove the inspiration for other railway companies around the UK to incorporate the technology. Still, the telegram was focused on assisting with train management, as opposed to public messages.

It was around this time W.F. Cooke proposed electronically managed block signaling, which enabled trains to travel on single tracks safely. At this point it relied on timetabling and trains running on schedule and would continue to do so for some time.

However, in a pamphlet entitled ‘Telegraphic Railway’ written in 1842, Cooke wrote: “It may be considered that the maximum degree of safety attainable by subsidiary regulations has already been achieved on the great double lines of railway” and that “to the comparatively high degree of safety now (1842) obtained in travelling, depending upon, as I have said, the vigilance and punctuality in the conduct of trains it is proposed to add a layer of physical certainty of their relative places on the line at any moment.” (via Railway Signalling, James Pegg, 1897.)

Wider adoption begins

While it would be over a decade before this ambition would start to be realised, more and more railway lines around the UK were adopting Cooke’s existing technology. Meanwhile, further innovations saw letters received via a single rotating dial and the ability, for the first time to print the messages out on paper.

The Edinburgh and Glasgow Railway, The Leeds & Manchester Railway, and the Yarmouth & Norwich Railway and the London & Croydon railway, Dublin & Kingstown Railway, would all have their own lines, custom built to their needs, most of whom were also paying a per-mile licence fee on top of the installation costs.

Cooke and Wheatstone also gained a patent in the United States and in Europe, allowing electric telegraph systems to be built in France, Germany and Belgium alongside the railways.

A new arrangement of a two-needle system powered by overhead wires would become known as the patent-protected ‘Cooke & Wheatstone's Telegraphic System’.

[Read more: A short history of telecommunications in the UK]

Messaging opens to the public

It was not until 1843 that the first public access was granted to telegraphs, enabling the public, for a fee, to exchange messages across the Great Western Railway lines. Sending a message cost one shilling and the service, Roberts writes, was regularly used by the royal household close to send and receive messages. The Telegraph Office at Slough even welcomed school visitors and foreign dignitaries.

Telegraph patents - BT Archives

The following year, in 1844, Cooke and Wheatstone earned a real breakthrough with the first long telegraph system in Britain, spanning 77 miles on the London & South-Western line. It allowed messages to be passed from Nine Elms in London all the way to Gosport through the major port of Southampton. The 124-mile South Eastern line from London to Dover followed soon after and was completed in 1846 and soon every other major rail network in the United Kingdom had a system that derived from the patent granted 180 years ago this week.

The Electric Telegraph Company, formed the previous year, bought out the Cooke and Wheatstone patents for £141,400, prompting the great expansion of telegraph technology into the public domain. The patents (above) are held in the BT Archives.

The Bill, which passed in an Act of Parliament in 1846 mandated that the lines of communication, dubbed “the railway of thought”, be open to everyone, not just railway line owners.

Photo credit: BT Archives

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