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.
Signal Corps in the American Civil War
Telegraph trains were introduced by Myer to support telegraphy for mobile operations. The horse-drawn wagons carried the telegraph sets and supplies such as reels of insulated copper wire and iron lances, for stringing temporary field lines, a practice called "flying telegraph lines." Each train consisted of two wagons, equipped with 5 miles of wire and a telegraph instrument. The first model train was constructed by Henry J. Rogers, a telegraphic engineer from New York City who had worked with Samuel F.B. Morse in building the first commercial telegraph line between Washington and Baltimore in 1844. Rogers's original telegraph instrument for the train replaced the traditional sending key and sound receiver with a dial indicator, a circular index plate bearing the letters of the alphabet and a pointer that turned to the letter to be transmitted. A similar pointer spelled out the message at the receiving end. Rogers provided a galvanic battery that eliminated the danger of acid spills. This equipment eliminated the need for skilled operators who had to be trained in Morse code. Field trials in February 1862 found that it worked satisfactorily over a test circuit of 2 miles of wire. A board of three signal officers recommended that such a train would be of great use as an auxiliary to permanent telegraph lines.