Cooke and Wheatstone Telegraph (1837): Britain's First Line

The Cooke and Wheatstone telegraph was the first electric telegraph to enter commercial service. Patented in London in June 1837 by William Fothergill Cooke and Charles Wheatstone, it used electric currents to swing magnetic needles that pointed to letters. Its first commercial line, opened beside the Great Western Railway in 1839, began the age of near-instant long-distance communication in Britain.

Background

Scientists had experimented with electrical signalling for decades. After Hans Christian Ørsted showed in 1820 that an electric current deflects a compass needle, several inventors used the effect to send signals. Pavel Schilling demonstrated a needle telegraph in St Petersburg in the early 1830s, and in 1833 Carl Friedrich Gauss and Wilhelm Weber linked buildings in Göttingen with a telegraph wire.

William Fothergill Cooke (1806–1879), a former officer in the Indian Army who had been studying anatomy in Germany, saw a demonstration of a Schilling-type needle telegraph at Heidelberg in March 1836. He returned to England determined to make a practical system, especially for the new railways, which needed a fast way to send messages along their lines.

The partnership and the patent

Cooke’s early devices ran into scientific problems, particularly in sending currents over long wires. In 1837 he sought advice from Charles Wheatstone (1802–1875), professor of experimental philosophy at King’s College London, who was already experimenting with telegraphy. The two formed a partnership: Cooke supplied the business drive and railway contacts, Wheatstone the scientific knowledge.

Their joint patent, taken out in June 1837, described a telegraph with five magnetic needles. On the receiving board, the letters of the alphabet were arranged in a diamond pattern. Currents sent along the wires caused two of the needles to swing so that they pointed together at the chosen letter. Because only 20 letters could be shown, C, J, Q, U, X and Z were left out, and operators spelled words around the gaps.

On 25 July 1837 the partners demonstrated the system along the London and Birmingham Railway between Euston and Camden Town, about 1.5 miles. The railway’s directors were impressed but did not adopt it.

The Great Western Railway line

The breakthrough came with the Great Western Railway, whose engineer, Isambard Kingdom Brunel, supported the idea. A line from Paddington to West Drayton, about 13 miles, opened on 9 July 1839, the first commercial electric telegraph in the world. The wires were at first laid in iron pipes beside the track, which proved troublesome; later lines were hung on poles.

Over the next few years the partners simplified the apparatus. Two-needle and then single-needle instruments, which used codes of needle movements to the left and right, needed fewer wires and became standard. In 1843 the Great Western line was extended to Slough, and members of the public could pay to send messages.

The Tawell case

The telegraph won fame in January 1845. On 1 January John Tawell murdered Sarah Hart at Salt Hill near Slough and boarded a train to London. Staff at Slough telegraphed a description to Paddington, saying that the suspect was dressed in the clothing of a Quaker. Because the instrument lacked a Q, the word was famously sent as “KWAKER”. A police officer followed Tawell when he arrived and he was arrested the next morning. His conviction and hanging in March 1845 made the telegraph a household name.

Rivalry and expansion

The partners fell out over who deserved credit. In 1841 an arbitration by the engineer Marc Isambard Brunel and the chemist John Frederic Daniell concluded that Cooke was the practical entrepreneur and Wheatstone the scientist responsible for bringing the invention to public notice, but the quarrel continued in print for years.

In 1846 Cooke and the financier John Lewis Ricardo founded the Electric Telegraph Company, which bought the patents and built a national network. In the United States, Samuel Morse developed a different system that sent coded pulses rather than moving pointers, opening his Washington–Baltimore line in 1844. Morse’s code eventually became the international standard, but single-needle instruments stayed in use on British railways well into the 20th century. Both men were knighted, Wheatstone in 1868 and Cooke in 1869.

Timeline

• 1820: Ørsted discovers that an electric current moves a compass needle.
• 1836, March: Cooke sees a needle telegraph demonstrated at Heidelberg.
• 1837, June: Cooke and Wheatstone take out their joint patent.
• 1837, 25 July: Demonstration between Euston and Camden Town.
• 1839, 9 July: The Paddington–West Drayton line opens on the Great Western Railway.
• 1843: The line is extended to Slough.
• 1845, 1 January: A telegraph message leads to John Tawell’s arrest.
• 1846: The Electric Telegraph Company is founded.

Why it matters

The Cooke and Wheatstone telegraph separated communication from transport for the first time on a commercial basis: a message no longer had to travel as fast as a horse or train. Its use on railways made train working safer, and the networks it began grew into national and then undersea international systems that transformed news, business and government.