Punchings and drillings are also treated by the process known as “puddling.” In this case, the furnaces will have a cavity in the floor, into which the small scrap material is shovelled or tipped. The door is now made fast and the heat applied, which must not be too fierce, however, or the whole mass would soon be burned and spoiled. When the drillings and chippings have cohered, the puddler, by an aperture through the iron door, inserts a steel bar, curved at the end, and prises the lump and turns it over and over. This is called “balling up.” By and by, when the iron is thoroughly heated and fairly consistent, it is brought to the “shingler,” who soon gives it shape and solidity. At the first few blows a terrific shower of sparks shoots around, which travel for a great distance, burning everything they meet. To protect themselves against this the shinglers wear heavy iron jackboots, reaching above the knees, with an iron veil over their eyes and faces. As the steam-hammer block upon which the pounding is done is only a few inches above the floor level and the sparks and splinters fly out with the precision of shot from a gun barrel, the danger is confined to a space within two feet of the floor.
When the heats come from the puddling furnaces they look soft and spongy and soon become dull on the outer parts, so that a stranger might think them not sufficiently hot to beat up, but after the first light blow or two he will find himself mistaken. First of all the huge hammer--able to strike a blow equal to a hundred tons pressure--is merely allowed to squeeze the mass, without beating it. Then it rises gently and travels up and down, scarcely touching the metal. Gradually the blows fall harder and harder until the piece is fully consistent; then it is rapidly drawn away to the rolls. Very rarely are the hammers required to expend their full powers upon the melting slabs, unless they happen to be of steel, which is very hard, even when whitehot. Then the blows fall terrific. The steam spouts, roars, and hisses; the chains jingle and the ground under your feet shakes as though in an earthquake.
When a better quality of iron is required the punchings, bolts, and rivets are placed in a large drum which is afterwards set in motion and continues to revolve for several hours. By this means all the rust, paint, and dirt are removed from the metal, and when it is taken from the cylinder it shines like silver. Special regard is had for this in the furnaces. Care is taken to save it from over-heating and waste, and when it finally emerges from the rolls it is set apart by itself and labelled for its superior quality.