††††Henry developed the first electromagnetic telegraph in 1831. It sent an electric charge through 1500 metres of wire. An electromagnet produced a force on a suspended permanent magnet that swivelled and rang a bell. In 1835 Samuel Morse, inventor of the Morse Code, used an electromagnet and made a working model of a telegraph.
The first practical telegraph in England was set up in 1837 by William Cooke and Charles Wheatstone. It linked two London railway stations a mile apart and used a five-needle galvanometer to indicate the transmitted letters.
By 1850 the telegraph network extended to 5600 kilometres (3,500 miles). Until 1880, when telephones became more generally available, the telegraph was the main means of rapid communication within a district.
