He was corresponding member of the principal academies of science in Europe.
It was by his skill in turning knowledge to practical account that Wheatstone gave the electric telegraph the character which it now possesses. Though his inventions in other branches of science are as numerous as they are various, yet it is in connection with the electric telegraph that the name of Wheatstone will live.
He was the inventor of the telegraph, indeed. No one else can lay claim to that title.
Stephen Gray, in 1827, suspended a wire, seven hundred feet long, on silk threads, and on applying an excited glass tube to one end, electrification was observed at the other, but he did not send messages. Advances were made from that time by many men of science, who saw more or less clearly the great possibilities before them.
Omitting the pioneer claims of Sommering, Lomond and others of the last century, the names connected with the early development of the practical telegraph are Froment in France, Gauss, Weber and Steinheil, in Germany, Sir Francis Ronalds and Edward Davy, in England, Morse and Vail, in America. But to Wheatstone and his co-adjutor Sir William Fothergill Cooke is due the merit of having been the first to render it available for the public transmission of messages.
In 1834, shortly after being appointed Professor of Experimental Physics at King’s College, London, Wheatstone began experimenting on rate of transmission electricity along wires. For this purpose about half a mile of copper wire was insulated by suspension in the vaults under the college, and three interruptions of this circuit was made by three parts of brass knobs with a small interval between them, one of these interruptions was in the middle point of the conductor and the other two near the ends.
A leyden jar was discharged through the wire and the interval of time between the occurrence of the sparks at the ends and occurrence of the spark at the middle was measured by noting the displacement of the image of the middle spark in a mirror revolving at a known speed. It was calculated from results of this experiment that the velocity of an electric disturbance along a wire was about two hundred and fifty thousand miles per second, a result differing from the true speed of one hundred and eighty-six thousand miles per second; not very widely, considering the difficulties of observation in an experiment of this kind. From this research he passed on to the transmission of messages by electricity, and in conjunction with Cooke he elaborated the five needle telegraph, the first that came into general use.
Wheatstone’s fertility of scientific resource led the partners on to many new developments.
The letter showing dial telegraph in 1841 and the magneto-electro dial telegraph, a subsequent extension of the same to type embossing, and lastly the automatic transmitting and receiving instruments by which messages are sent with such great rapidity.
He was the first to appreciate the importance of reducing to a minimum the amount of work to be done by the current at the receiving station by diminishing as far as practicable the mass and therefore the inertia of the moving parts.