From 1858 to 1864, the company were engaged in endeavoring to raise new capital, and to obtain increased subsidies from the English and American governments; while scientific men were making improvements in the form of cable, and iu the apparatus for submerging it. At length the Telegraph Construction and Maintenance company (formed by an amalgamation of the Gutta-percha company with the wire-cable-making firm of Glass & Elliott) made an entirely new cable, much thicker and more costly than the former one. The conductor, 300 lbs. per mile, and 4th in. thick, consisted of 7 No. 18 copper wires, each in. thick. The core was formed of four layers of gutta-percha alternating with four of Chatterton's compound (a solution of gutta-percha in Stockholm tar); the core and conductor together were 700 lbs. per mile, and in. thick. Out side this was a jacket of hemp or jute yarn, saturated with preservative composition. The sheath consisted of 10 iron wires, No. 13 gauge, each previously covered with 5 tarred manilla yarns. The whole cable was in. thick, and weighed 351 cwt. per mile, with a breaking strain of 7# tons.
As the cable (2300 m.) weighed more than 4000 tons, it was resolved to employ the Great Eastern steamship to carry it out and lay it. Three enormous iron tanks were built in the fore, middle, and aft holds, from 50 to 60 ft. diameter each, by 20i ft. deep; and in these the cable was deposited, in three vast coils. On July.23, 1865, the Great Eastern started from Valentin with her burden, the main cable being joined end to end to a more massive shore cable, which was drawn up the cliff at Foilhummerum bay, to a telegraph house at the top. The electric condition of the cable was kept constantly under test during the progress of the ship; and more than once the efficiency was dis turbed by fragments of wire piercing the gutta-percha and destroying the insulation. On Aug. 2, the cable snapped by over-straining, and the end sank to the bottom in 2000 fathoms water, at a distance of 1064 in. from Ireland. Then commenced the remarkable process of dredging for the cable. A five-armed grapnel, suspended from the end of a strong iron-wire rope, 5 m. long, was thrown overboard; and when it reached the bot tom, it was dragged to and fro across the line of cable by slow steaming of the Great Eastern; the hope being that one or other of the prongs would catch hold of the cable. A series of disasters followed by the breaking of swivels, and the loss of grapnels and ropes; until at length, on Aug. 11, it was found that there were no more materials on board to renew the grappling. The Great Eastern returned to England, leaving (including the operations of 1857-1858) nearly 4000 tons of electric cable useless at the bottom of the Atlantic.
A new capital, and new commercial arrangements altogether, were negilful for a renewal of the attempt. Another cable was made, slightly differing from the former. The jacket outside the core was made of hemp instead of jute; the iron wires of the sheath were galvanized, instead of being left in their natural state; and the manilla hemp which covered them was left white instead of being tarred. These few changes made it weigh nearly 500 lbs. per mile less, mainly through the absence of tar; while its strength or breaking strain was increased. Enough of this cable was made to span the Atlantic, with allowance for slack; while a sufficient addition of the 1865 cable was pro vided to remedy the disaster of that year.
The A. T. operations in 1866 were of a remarkable and interesting kind. On July 13, the Great Eastern set forth from Valentia, accompanied by the steamers Terrible, _Med way, and Albany, which were to assist in the submersion and in subsidiary matters. The line of route was chosen midway between those of the 1858 and 1865 cables, for the most part a few miles from each: The Great Eastern exchanged telegrams almost continuously with Valentia during her progress. The mishaps were few in number, and easily remedied; and the Great Eastern safely entered the harbor of Heart's Content, Newfoundland, on the 27th. After this, operations commenced for recovering the end of the 1865 cable, and completing the submersion. The Albany, Medway, and Terrible set off, on Aug. 1, to the spot on the ocean beneath which the end of the cable was lying, or as near to it as calculations could establish. Certain buoys, left anchored there twelve months pre viously, had been carried away by the storms of the preceding winter; but the latitude and longitude had been very carefully registered. The Great Eastern started from Heart's Content on the 9th, and then commenced a series of grappling operations, which continued through the rest 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. After much trial of patience, the end of the cable was safely fished up on Sept. 1; and electric messages were at once sent through to Valentin, 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.