In 1837, Professor Stratingh, of Groninque, Holland, devised a telegraph in which the signals were made by electro-magnets actuating the hammers of two gongs or bells of different tone; and M. Amyot invented an automatic sending key in the nature of a musical box. From 1837-8, Edward Davy, a Devonshire surgeon, exhibited a needle telegraph in London, and proposed one based on the discovery of Arago, that a piece of soft iron is temporarily magnetised by the passage of an electric current through a coil surrounding it. This principle was further applied by Morse in his electro-magnetic printing telegraph. Davy was a prolific inventor, and also sketched out a telegraph in which the gases evolved from water which was decomposed by the current actuated a recording pen. But his most valuable discovery was the 'relay,' that is to say, an auxiliary device by which a current too feeble to indicate the signals could call into play a local battery strong enough to make them. Davy was in a fair way of becoming one of the fathers of the working telegraph, when his private affairs obliged him to emigrate to Australia, and leave the course open to Cooke and Wheatstone. CHAPTER II. CHARLES WHEATSTONE. The electric telegraph, like the steam-engine and the railway, was a gradual development due to the experiments and devices of a long train of thinkers. In such a case he who crowns the work, making it serviceable to his fellow-men, not only wins the pecuniary prize, but is likely to be hailed and celebrated as the chief, if not the sole inventor, although in a scientific sense the improvement he has made is perhaps less than that of some ingenious and forgotten forerunner. He who advances the work from the phase of a promising idea, to that of a common boon, is entitled to our gratitude. But in honouring the keystone of the arch, as it were, let us acknowledge the substructure on which it rests, and keep in mind the entire bridge. Justice at least is due to those who have laboured without reward. Sir William Fothergill Cooke and Sir Charles Wheatstone were the first to bring the electric telegraph into daily use. But we have selected Wheatstone as our hero, because he was eminent as a man of science, and chiefly instrumental in perfecting the apparatus. As James Watt is identified with the steam-engine, and George Stephenson with the railway, so is Wheatstone with the telegraph.