Heroes of the Telegraph/Chapter 4

As early as 1823 Mr. (afterwards Sir) Francis Ronalds had observed that electric signals were retarded in passing through an insulated wire or core laid under ground, and the same effect was noticeable on cores immersed in water, and particularly on the lengthy cable between England and the Hague. Morse proclaimed his faith in it as early as the year 1840, and in 1842 he submerged a wire, insulated with tarred hemp and india-rubber, in the water of New York harbour, and telegraphed through it. India-rubber had been tried by Jacobi, the Russian electrician, as far back as 1811. He laid a wire insulated with rubber across the Neva at St. Petersburg, and succeeded in firing a mine by an electric spark sent through it; but india-rubber, although it is now used to a considerable extent, was not easy to manipulate in those days. 525. And when as here the danger had been called fully into existence by the defendant it could not escape liability for the result of conditions that it alone knew, had created and had arranged to have continue, by stepping out of the control a few days before the event came to pass.

It is certain that while the victor has been forgotten, the vanquished has created a world-wide renown. While at Cambridge he took an active part in the field sports and athletics of the University. That entering the signal magnet expends part of its force in the magnetism of the core. These messages were the signal for a fresh outburst of enthusiasm. We owe it to his admirable inventions, the mirror instrument of 1857 and the siphon recorder of 1869, that messages through long cables are so cheap and fast, and, as a consequence, that ocean telegraphy is now so common. At the age of seventeen, when ordinary lads are fond of games, and the cleverer sort are content to learn without attempting to originate, young Thomson had begun to make investigations. He was educated at the Merchant Taylors' School from 1840 to 1847, and then, at the age of fifteen, with his brother entered the employ of the Electric Telegraph Company, which had been formed to work the patents of Cooke and Wheatstone.

It was due to the brilliant promise he displayed, as much as to the influence of his father, that at the age of twenty-two he found himself wearing the gown of a learned professor in one of the oldest Universities in the country, and lecturing to the class of which he was a freshman but a few years before. It is not enough to say the young Glasgow professor threw himself heart and soul into their work. But seeing that the cable was to land on British soil, it was fitting that the work should be international, and that the British people should be asked to contribute towards the manufacture and submersion of the cable. He induced the American Government to despatch Lieutenant Berryman, in the Arctic, and the British Admiralty to send Lieutenant: Dayman, in the Cyclops, to make a special survey along the proposed route of the cable.

The route she was to follow was marked by a line of buoys and flags. A good insulator to cover the wire and prevent the electricity from leaking into the water was requisite for the success of a long submarine line. A presentiment of success may have inspired him; but he was ignorant alike of submarine cables and the deep sea. The practical advantage of this extreme delicacy is, that the signal waves of the current may follow each other so closely as almost entirely to coalesce, leaving only a very slight rise and fall of their crests, like ripples on the surface of a flowing stream, and yet the light spot will respond to each. That is to say, in any particular cable the speed of a signal is diminished to one-fourth if the length is doubled, to one-ninth if it is trebled, to one-sixteenth if it is quadrupled, and so on. At length the shadow ceased to move. The declining sun,' he says, 'enabled me to discern the moving shadow of the steamer's smoke on the white cliff; thus indicating her progress.

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