King Maximilian had seen how the French visual semaphore system had helped Napoleon's military campaigns and in 1809 he asked the Bavarian Academy of Sciences to devise a scheme for high-speed communication over long distances. Sömmering suggested a crude telegraph using 35 conductors, one for each character. Sömmering's telegraph transmits electricity from a battery down one of these 35 wires where, at the receiver, the current is passed through a tube of acidified water. Passing a current through the water breaks it down into oxygen and hydrogen. To use the Sömmering telegraph you detected the bubbles that appeared in one of the 35 glass tubes and then wrote down the corresponding character. Sömmering's telegraph was ingenious but too slow to be practical.

Many important technological events took place at the end of the 19th century, all of which were required to construct a practical computer. The most important of these events was the invention of the telegraph. In 1819 H. C. Oersted made one of the greatest discoveries of all time when he found that an electric current creates a magnetic field round a conductor. This was a major breakthrough because it allowed you to create a magnetic field at will. In 1828 Cooke exploited Oersted’s discovery when he invented a telegraph that used the magnetic field round a wire to deflect a compass needle.

 The growth of the railway networks in the early nineteenth century was one of the driving forces behind the development of the telegraph because you had to warn stations down the line that a train was arriving. By 1840 a 40-mile stretch between Slough and Paddington in London had been linked using the Wheatstone and Cooke telegraph. 

The Cooke and Wheatstone's telegraph used five compass needles that normally hung in a vertical position. Coils to the left and right of the needles allows the needles to be deflected left or right when energized. Two switches are pressed as the same time to move two needles. The needles point to the appropriate letter. This arrangement allows you to transmit one of twenty letters. The letters J, C, Q, U, X and Z were omitted.

The Cooke and Wheatstone telegraph