When the core was covered in with its great coat of hemp and tar, and carefully gauged to ascertain the equality of its dimensions everywhere, it was ready to be turned into the completed Cable. This final operation was effected as the core was drawn up through the centre of a horizontally revolving wheel or table. The table turned with great rapidity, and carried near its circumference eighteen bobbins or drums. Each of these drums was filled with a strand of bright charcoal iron wire, and had two motions, one round its horizontal axis, and one round an upright pivot, inserted into the revolving table, so that it delivered its strand always towards the centre of the table as it was carried swiftly round by the revolution. The iron strand was of the same diameter as that which was used for the copper core. There were also seven iron wires in each strand, exactly like those for the copper strand. Eighteen iron strands were thus firmly twisted round the central core, as the “closing machine” whirled. The core, acted on by the rollers of the machinery, rose through the middle of the table, and went up towards the ceiling. The iron strands danced round it, as it went up, in a filmy-looking spectre-like cone, which narrowed and grew more matter-of-fact and distinct as it ascended, until it glittered in a compact metallic twist, tightly embracing the core. The eighteen strands of seven-thread wire were used for this metallic envelope in place of eighteen simple wires of the same size as the strand, because by this means greater flexibility and strength were obtained for the weight of material employed. Each strand machine worked day and night, and in the twenty-four hours spun ninety-eight miles of wire into fourteen miles of strand. There were several strand machines at work in the factories, and these every twenty-four hours made 2,058 miles of wire into 294 miles of strand. As much as thirty miles of Cable were made in a single day. The entire length of wire, copper, and iron employed in the manufacture, amounted to 332,500 miles, enough to girdle the earth thirteen times. As the closed Cable was completed, it was drawn out from the wall of the factory, and passed through a cistern containing pitch and tar, and was then coiled in broad pits in the outer yard (each layer of the coil having been again brushed over with pitch and tar), and there remained until embarked on board the vessel which conveyed it to its final home. At both the Greenwich and Birkenhead works, four Cables, each three hundred miles long, were simultaneously in process of construction. These were finally united together into one continuous rope, as the Cable was stowed away in the vessel which carried it to sea. Such is a description of the Cable finally adopted, and which when completed weighed from nineteen hundredweight to one ton per mile, and bore a direct strain of from four to five tons without breaking.