Cooke and Wheatstone telegraph
The Cooke and Wheatstone telegraph was an early electrical telegraph system dating from the 1830s invented by English inventor William Fothergill Cooke and English scientist Charles Wheatstone. It was the first telegraph system to be put into commercial service. The receiver consisted of a number of needles which could be moved by electromagnetic coils to point to letters on a board. This feature was liked by early users who were unwilling to learn codes, and employers who did not want to invest in staff training.
Needle telegraph
A needle telegraph is an electrical telegraph that uses indicating needles moved electromagnetically as its means of displaying messages. It is one of the two main types of electromagnetic telegraph, the other being the armature system as exemplified by the telegraph of Samuel Morse in the United States. The principal needle system was the Cooke and Wheatstone telegraph, a system widely used in Britain and the British Empire in the 19th and early-20th centuries. However, the earliest needle telegraph was a binary coded multi-wire, multi-needle system invented by Pavel Schilling and demonstrated in St. Petersburg in 1832. Charles Wheatstone may have demonstrated one of Schilling's instruments in 1835 (that is, prior to his collaboration with Cooke to build a telegraph). Cooke definitely saw Schilling's needle instrument at a lecture of Georg Wilhelm Muncke in Heidelberg. It was this lecture that inspired Cooke to attempt building a telegraph, although he did not use needle instruments until Wheatstone came on board and suggested it.