William Fothergill Cooke was English inventor who worked with Charles Wheatstone in developing electric telegraphy.
William Fothergill Cooke, a British electrical engineer, was born on May 4, 1806, in Ealing, Middlesex, England. He became interested in electrical telegraphy when he was a child. His interest may have resulted fromwatching his father and Francis Ronalds transmitting messages from the coach house to the tool shed at the end of the garden when he was a boy. After eight years of military service with the East India Company, William Fothergill Cooke left to study anatomy at the University of Heidelberg, Germany.
In 1836 he attended a physics lecture of G.W. Munke at the University at which one of Baron Schilling’s needle telegraphs was demonstrated. Although Cooke had no knowledge in electronics he recognised the chance of this invention for the future.
It must have made a tremendous impression on him for within three weeks he had made a telegraph of his own. Cooke was seized with the idea of making a commercially practical telegraph system based on the needlegalvanometer. He was not convinced that his telegraph would be able to transmit over long distances so he arranged a meeting with the noted physicist Professor Wheatstone, who was interested in both sound and electricity. From this single meeting developed a working partnership which culminated in the demonstration of the first working electric telegraph in the world.
During this time the English physicist Charles Wheatstone was experimenting with electricity at King’s College, London. There he made his famous determination of the propagation velocity of electricity. Wheatstone showed that all the effects possible with a short wire could also be produced by a long one, and that the results were to all practical purposes instantaneous. By June 1836, he had demonstrated how this technology could be turned into a telegraph.
In March 1837 Cooke had problems with his telegraph. It seemed that the electrical power could not transmit a signal over long distances. He asked professor Wheatstone for advice. It was found that Cooke had forgottento observe Ohm’s Law and that the multiplier winding had been miscalculated.
Wheatstone and Cooke formed a partnership of convenience. Cooke was an entrepreneur in search of a fortune, Wheatstone an academic who understood the science of electricity. In June 1837, they were granted their first patent on an instrument using six wires, connected to five galvanometer needles arranged in a row across the face of a grid which displayed 20 letters of the alphabet. Each letter was sent in the form of currents flowing down two wires, causing the appropriate needles to swing against stops and point to the right letter. Complex to describe, the system was simple to use: children could, and did, operate it successfully.
Cooke and Wheatstone’s telegraph employed five iron needles which when not in use rested in a vertical position. Each needle could be moved either to the left or the right by electromagnets. To transmit a letter of the alphabet two switches were pressed which caused two needles to move and point to the appropriate letter. By pressing different combinations of switches any one of twenty letters could be transmitted. Unfortunately J, C, Q, U, X and Z had to be omitted making it difficult to send some words. Alternative methods were adopted to spell words such as ‘queen’, ‘quiz’ or ‘axe’. Despite its shortcomings, the advantage of their equipment was that it could be used by unskilled operators.
Cooke’s business acumen played a crucial role in the success of their telegraph. He realised the potential of an almost instant method of sending messages for the new railway companies, and in 1837 he arranged a demonstration between Euston and Camden stations, a distance of 1.5 miles (2.4 km). There were problems in insulating the iron wires which carried the signal. The wires were covered with cotton and buried in iron pipes beside the railway line. While the wires remained dry there was no problem, but if they became wet the insulation failed. Nevertheless, the equipment clearly impressed the Directors of the Great Western Railwaywho allowed a trial to take place between Paddington and West Drayton.
The trial was a partial success. The company did not accede to Cooke’s request to extend it to Bristol, but did agree an extension as far as Slough, provided railway messages were carried free of charge. Cooke overcame the insulation problems by suspending the wires from iron posts using glass insulators. This extension was paid for by Cooke and Wheatstone and to recover some of the expense they offered the public the opportunity to send messages at a shilling (5 p) a time.
Although the five needle telegraph was easy to operate it required six wires, the cost of the first model made it impractical. Before the telegraph was used in all English railway lines, Wheatstone had to improve it.
Cooke & Wheatstone replaced their first model in 1843 with a new type, using just two needles (and therefore three electrical wires). The letters of the alphabet were identified by counting the number of deflections ofthe needle, rather than the single deflection method of the five-needle instruments. This was the equipment that achieved fame by warning of murderer seen leaving Slough in 1845, leading to his arrest at Paddington. It is worth noting that the two needles were marked for Up Trains and Down Trains, suggesting their later use for signalling purposes.
Letters of the alphabet were identified by multiple strokes of the needle, but it is not clear as to whether the two circuits were used independently for “Down” and “Up” messages, or whether the separate needles were used for sending and receiving messages.
Another improvement was the one-needle telegraph of 1845. The principle of this apparatus was not new, Steinheil had already proposed it in 1837.The needle stroke against small metal pipes that emitted sounds in different pitches. That “two tone melody” represented a code of the telegram. On the single-needle instruments, the Cooke & Wheatstone and other complex codes were abandoned and instead messages were sent morse code. The needles no longer required to be observed visually to be read – metal sounders were provided so that deflections could be identified by ear as a “ting” and a “tong”. These sounders were, in fact, often enhanced by signalmen by the placing of a tobacco tin tightly on the sounders, producing a sharp “click” and “clack”.
A quarrel between Cooke and Wheatstone over credit for the invention was settled amicably in 1841 but flared again a few years later. Wheatstone is generally considered the more important of the two in thehistory of the telegraph, but Cooke contributed a superior business ability. Their most important invention, an electric telegraph using only one magnetic needle instead of several, was recognized by patent in 1845. Cooke was knighted in 1869 and granted a civil-list pension in 1871 for his services to telegraphy. Tragically he had by then developed financial problems and, although he had once earned a fortune, he died on June 25, 1879, Surrey, England, almost penniless.