The land telegraph having had such success, the next step was to carry the wires across the deep, and link continent to continent,—an all-important step for an island kingdom such as ours, with its legion of distant colonies. The success of a submerged cable between Gosport and Portsmouth, and of one across the docks at Hull, proved the feasibility of a water telegraph, at least on a small scale, and it was not long before more ambitious attempts were made. On the 28th of August 1850, a cable, 30 miles long, in a gutta percha sheathing, was stretched at the bottom of the straits between Dover and Cape Grisnez, near Calais. Messages of congratulation sped along this wire between England and France; and although a ridge of rocks filed the cable asunder on the French coast, the suspension of communication was only temporary. The link has once more been established, and is in daily use. The first news sent by the wire to England was of the celebrated coup d'etat of the 2d December, which cleared the way for Louis Napoleon's ascent of the throne. Numerous other cables have since been sunk beneath the waters; complete telegraphic communication has just been established between England and India, and will, no doubt, before long be extended to Australia. The greatest enterprise of this kind, however, still remains unaccomplished—that is, the laying of the Atlantic cable. A company was started in 1856 to carry out this great enterprise, the governments of Great Britain and the United States engaging to assist them, not only with an annual subsidy of £10,000 a-year for twenty-five years, but to furnish the men and ships required for laying the cable from one side of the Atlantic to the other. The chief difficulty which engaged the attention of Mr. Wildman Whitehouse and the other agents of the notable enterprise was the enormous size of the cable which, it was thought, would be necessary. The general belief at that time was, that the greater the distance to be traversed, the larger must be the wire along which the electric current was to pass, and that the rate of speed would be in proportion to the size of the conductor. Mr. Whitehouse, however, thought it would be as well to begin by making sure that this was really the case, and that a monster cable was essential; and after some three thousand separate observations and experiments, was delighted to find that the difficulty which stared them in the face was imaginary. Instead of a large cable transmitting the current faster than a small one, he ascertained beyond a doubt, that the bigger the wire, the slower was the passage of the electricity. It would be needful, therefore, to make the cable only strong enough to stand the strain of its own weight, and heavy enough to sink to the bottom. A single wire would have been quite sufficient, but a strand of seven wires of the finest copper was used for the cable, so that the fracture of one of them might not interfere with the communication,—as long as one wire was left intact the current would proceed. A triple coating of gutta percha, to keep the sea from sucking out the electricity, and a thick coating of iron wire, to sink the cable to the bottom and give it strength, were added to the copper rope, and then the cable was complete. No less than 325,000 miles of iron and copper wire were woven into this great cable,—as much as might be wound thirteen times round the globe; and its weight was about a ton per mile. The length of the cable was 18,947 miles—some 600 miles being allowed to come and go upon, in case of accidents.

The end of July 1857 was selected for the sailing of the ships that were to lay the cable, as fogs and gales were then out of season, and no icebergs to be met with. On the 8th of August, the Agamemnon (English) and Niagara (American), with four smaller steamers to attend them, and each with half of the mighty cable in her hold, got up their steam and left Valentia Harbour. One end of the cable was carried by a number of boats from the Niagara on shore, where the Lord-Lieutenant was in waiting to receive it, and place it in contact with the batteries, which were arranged in a little tent upon the beach. A slight accident to the cable for a little while delayed the departure of the ships; but by the 10th they had got 200 miles out to sea, and so far the cable had been laid successfully. Messages passed and repassed between the ships and the shore. The next day the engineer discovering that too much cable was being paid out, telegraphed to the people on board to put a greater grip on it; the operation was clumsily managed, and the cable snapped, sinking to a depth of 12,000 feet.

Not disheartened, however, the Company replaced the lost portion of the cable; the Government again furnished ships and men, and the cable was actually laid at the bottom of the Atlantic from Valentia Bay to Trinity Harbour.

Addresses of congratulation passed between the Queen and the President of the States, and numerous messages were transmitted. But gradually the signals grew fainter and more faint, till they ceased altogether. The cable was stricken dumb. A little to the north of the fiftieth parallel of latitude, at the bottom of the Atlantic, where the plateau is unbroken by any great depression, some 1500 miles of the disabled cable were lying, on a soft bed of mud, which was constantly thickening, at a depth of from 10,000 to 15,000 feet.

The importance of telegraphic communication between England and the United States was, however, so obvious that its projectors were not to be daunted by the failure they had sustained. Nor was it altogether a failure. They had proved that a cable could be laid, and messages flashed through it. What was wanted was evidently a stronger cable, which should be less liable to injury, and more perfect in its insulation of the telegraphic wires.

From 1858 to 1864, the Company were engaged in the difficult task of raising fresh funds, and in endeavouring to secure grants from the British and American Governments. Their men of science, meanwhile, were devising improvements in the form of cable, and contriving fresh apparatus to facilitate its submersion. Eventually the Telegraph Construction and Maintenance Company, an union of the Gutta Percha Company with the celebrated firm of Glass and Elliott, constructed an entirely new cable, which was not only costlier, but thicker and stronger than the preceding one. The conductor, three hundred pounds per mile, and one-seventh of an inch thick, consisted of seven No. 18 copper wires, each one-twentieth of an inch in thickness. The core or heart of the cable, says a writer in "Chambers's EncyclopÆdia," was formed of four layers of gutta percha alternating with four of Chatterton's compound (a solution of gutta percha in Stockholm tar); the wire and conductor being seven hundred pounds per mile, and nine-twentieths of an inch thick. Outside this was a coating of hemp or jute yarn, saturated with a preservative composition; while the sheath consisted of ten iron wires, each previously covered with five tarred Manilla yarns. The whole cable was an inch and one eighth thick, weighed thirty-five and three-quarter hundredweights per mile, and was strong enough to endure a breaking strain of seven tons and three-quarters. During the various processes of manufacture, the electrical quality of the cable was tested to an unusual extent. The portions of finished core were tested by immersion in water at various temperatures; next submitted to a pressure of six hundred pounds to the square inch, to imitate the ocean pressure at so great depth; then the conducting power of the copper wire was tested by a galvanometer; and various experiments were also made on the insulating property of the gutta percha. The various pieces having been thus severely put to the proof, they were spliced end to end, and the joints or splicings tested. In a word, nothing was left undone that could insure the success or guarantee the stability of the new cable.

When completed, the cable measured two thousand three hundred miles, and weighed upwards of four thousand tons. It was felt that such a burden could only be intrusted to Brunel's "big ship," the Great Eastern. For this purpose three huge iron tanks were built, in the fore, middle, and aft holds of the vessel, each from fifty to sixty feet in diameter, and each twenty and a half feet in depth; and in these the cable was deposited in three vast coils.

On the 23rd of July 1865, the Great Eastern left Valentia, the submarine cable being joined end to end to a more massive shore cable, which was hauled up the cliff at Foilhummerum Bay, to a telegraph-house at the top. The electric condition of the cable was continually tested during the ship's voyage across the Atlantic; and more than once its efficiency was disturbed by fragments of wire piercing the gutta percha and destroying the insulation. At length on August 2nd, the cable snapped by overstraining, and the end sank to the bottom in two thousand fathoms water, at a distance of one thousand and sixty-four miles from the Irish coast. Attempts were made to recover it by dredging. A five-armed grapnel, suspended to the end of a stout iron-wire rope five miles long, was flung overboard; and when it reached the bottom, the Great Eastern steamed to and fro in the direction where the lost cable was supposed to be lying; but failure followed upon failure, and the cable was never once hooked. There remained nothing to be done but for the Great Eastern to return to England with the news of her non-success, and leaving (including the failure of 1857-8) nearly four thousand tons of electric cable at the bottom of the ocean.

The promoters of ocean telegraphy, however, were determined to be resolute to the end. A new Company was formed, new capital was raised, and a third cable manufactured, differing in some respects from the former. The outside jacket was made of hemp instead of jute; the iron wires of the sheath were galvanized, and the Manilla hemp which covered them was not tarred. Chiefly through the absence of the tar, the weight of the cable was diminished five hundred pounds per mile; while its strength or breaking strain was increased. A sufficient quantity of this improved cable was made to cross the Atlantic, with all due allowance for slack; and also a sufficient quantity of the 1865 cable to remedy the disaster of that year.

On July 13th, 1866, the Great Eastern once more set forth on her interesting voyage, accompanied by the steamers Terrible, Medway, and Albany, to assist in the submersion of the cable, and to act as auxiliaries whenever needed. The line of route chosen lay about midway between those of the 1858 and 1865 cables, but at no great distance from either. The Great Eastern exchanged telegrams almost continuously with Valentia as she steamed towards the American continent; and great were the congratulations when she safely arrived in the harbour of Heart's Content, Newfoundland, on the 27th.

Operations were next commenced to recover the end of the 1865 cable, and complete its submergence. The Albany, Medway, and Terrible were despatched on the 1st of August, to the point where, "deep down beneath the darkling waves," the cable was supposed to be lying, and on the 9th or 10th they were joined by the Great Eastern, when grappling was commenced, and carried on through the remainder of the month. The cable was repeatedly caught, and raised to a greater or less height from the ocean bed; but something or other snapped or slipped every time, and down went the cable again. At last, after much trial of patience, the end of the cable was safely fished up on September 1st; and electric messages were at once sent through to Valentia, just as well as if the cable had not had twelve months' soaking in the Atlantic. An additional length having been spliced to it, the laying recommenced; and on the 8th the squadron entered Heart's Content, having thus succeeded in laying a second line of cable from Ireland to America.

The two cables, the old and the new, continued to work very smoothly during the winter of 1866 and 1867; but in May 1867, the new cable was damaged by an iceberg, which drifted across it at a distance of about three miles from the Newfoundland shore. The injury was soon repaired; but again, in July 1867, the same cable broke at about fifty miles from Newfoundland.

The earlier cable continued to work for several years, but both cables gave way towards the close of the autumn of 1870. No special inconvenience was felt, however, as two years ago a French line of cable was laid down between Europe and America; the Great Eastern being again employed, and the operations being conducted under the superintendence of English electricians. The two British cables will probably be repaired in the spring of the present year (1871).

Submarine cables have multiplied recently, and almost every ocean flows over the mysterious wires which flash intelligence beneath the rolling waters from point to point of the civilized world. By a telegraph-cable, which is partly submarine, the India Office in Westminster is united with the Governor-General and his Council at Calcutta. There is also communication between Singapore and Australia, and the network of ocean telegraphy is being so rapidly extended that, before long, the British Government in the metropolis will be enabled to convey its instructions in a few hours to the administrative authorities in every British colony. And thus the words which the poet puts into the mouth of "Puck" will be nearly realized in a sense the poet never dreamed of—"I'll put a girdle round about the world in forty minutes."