The iron wire with which the jute cover was surrounded was specially prepared for this purpose, and is termed by the makers (Messrs. Webster & Horsfall) "Homogeneous Iron." It was manufactured and rolled into rods at their works at Killamarsh, near Sheffield, and drawn at their wire factory at Hay mills, near Birmingham. This wire approaches to steel in regard to strength, but by some peculiarity in the mode of preparing it, is deprived entirely of that springiness which prohibits altogether the use of steel as a covering for the outsides of submarine cables. Ten wires were laid spirally round the core, and each of these wires was of No. 13 gauge, and was under contract to bear a strain of 850 to 1,100 lb., with an elongation of half an inch in every fifty inches within those breaking limits. The Cable, as completed and surrounded by these wires, had not the slightest tendency to spring, as would be the case if the metal were hard steel, and could be handled with great facility.
Before, however, these ten wires surrounded the core, each separate wire had to be itself covered with a jacket of tarred Manilla yarn, the object of which is at once to protect the iron from rust and to lighten the specific gravity of the mass, while adding also in some degree to the strength of the external portion of the Cable. The wire was drawn horizontally forward over a drum through a hollow cylinder, on the outside of which bobbins filled with Manilla yarn revolved vertically, and the yarns from these bobbins, being made to converge around the wire as it issued from the end of the cylinder, were thus spun tightly round the former. These Manilla-covered wires being wound upon large drums ready for use, the core, which we left some time back surrounded with jute, was passed round several sheaves, which conducted it below the floor of the factory, from whence it was drawn up again through a hole in the centre of a circular table, around the circumference of which were ten receptacles for ten drums, containing the Manilla-covered wire. Between these drums massive iron rods, fastened to the circumference of the table, rose, and converged around a small hollow cone of iron through the upper flooring of the factory, at a height of 12 or 14 feet above the table. The jute-covered core was pulled up vertically, and passed on straight through the hollow interior of the cone already mentioned, which latter formed the apex of the converging rods. This done, the ten wires from the ten drums were drawn up over the outside of the same cone, and as they rose beyond it converged around the core, which latter, being free from the revolving part of the machinery, was simply drawn out; while the circular table being now set revolving by steam power, the ten wires from the drums were spun in a spiral around the core, thus completing the Cable, which was hauled out of the factory by the hands of men, who at the same time coiled it into large iron tanks, where it was covered with water, and was daily subjected to the most careful electrical tests, both by the very experienced staff of the contractors and by the agents of the Atlantic Telegraph Company.