THE CATALAN FORGE.
The production of iron involves scientific questions of great and absorbing import ance; but it is scarcely possible for a pure philosopher, inexperienced in the art of elaborating the metals, to render much assistance to the improvement of their manu facture. Nor is it likely that the merely practical can add to our knowledge in this art, except by accident. Intelligence and experience are both required in this most im portant branch of industrial skill, not for the purposes of invention and improvement only, but to conduct successfully the elaboration of the metal from the ore. Experi ments in the manufacture of iron are costly, and ruinous in the event of failure. Even the most practical and intelligent hesitate to adopt theories, though ever so plausible and promising, because the risk is great and the danger of failure imminent, though the principle involved may be correct.
For instance ; the pwumatic mode of decarbonizing pig metal, or the conversion of cast iron into steel, was at first considered a failure ; and in this country, where the invention appears to have been first made, there was neither intelligence nor confi dence enough to appreciate its merits. It is now, however, an established fact ; and the probability is that the success of the invention will force us to pay tribute to. the intelli gence of England, as we have done in the past.
Yet there is as much room and opportunity for improvement in the production of iron direct from the ore as in the elaboration of iron and steel from the pig. The pro cess in common use has been but little improved since the Middle Ages. The moun tain-forge of to-day is much the same as it was five hundred years ago in Catalonia. We can see the opening for improvement,—the principle which requires development ; but the mechanical difficulties have not yet been overcome.
The treatment of the ores in the Catalan forge involves—first, their deoxidization, and second, their reduction, or conversion to iron.
The ore is first selected in the mine or quarry. All silicious and earthy portions are rejected ; and it often happens that there is more rejected than selected,—though the refuse may be good ordinary ore and fit for use in the blast-furnace. The picked ore is then laid in kilns, or large pyramidal piles, intermixed with brush, logs, or charcoal brasque, and " roasted" for several days. This torrefaction of the ores expels the moist
ure, and, to some extent, whatever sulphur or phosphorus it may contain, and reduces it to a friable, crumbling mass, which is readily pulverized by hand with a large, flat hammer or by machinery. It is always reduced to a powder before admittance to the hearth, in our mountain-forges ; but in some parts of Europe the roasted ore, in small particles, is laid in the "eiuset" or hearth, opposite the tuyers, and on the bottom of the hearth. We have never seen this practised here. Our forge-hands fill the hearth with charcoal, and when fully ignited the coal is covered with pulverized ore, which is thrown on with a peculiar flirt, so as to scatter it evenly over the glowing fire. Coal and ore are constantly added for about two hours, or until a loup is formed in the hearth. This is then manipulated and tried by the tools of the workman, and the cinder let off, when above its face. In from three to four hours the loup of iron and seera acquires the proper size. The blast is then shut off, and the ball drawn out of the hearth. It is generally held on its edge and pounded with a wooden maul, to partially drain off the cinder, before it is taken to the trip-hammer. Here the loup is dexterously handled by the hammer-man until it is drawn to an oblong and square- sided " bloom" of about two hundred pounds weight. The forge-man is generally his own hammer-man, and when the iron is sold in the shape of blooms this part of the operation occupies hot a small part of his time. But when the bloom is drawn into horse-shoe bars the work is laborious, though the production is not materially altered in either case, since the ope ration of deoxidizing the ores is progressing during the hammering process. While keep ing the forge-fire in full blast for the purpose of reheating the bars drawn from the bloom, pulverized ore is frequently sprinkled over the mass of glowing charcoal. This answers a double purpose: first, it produces a protecting coat of silicious and fluid mat ter, which prevents the bar from burning, and, second, the ore is being prepared to form the next loup. Therefore, but a comparatively small amount of time is lost during the reheating and hammering process, as the common forges are operated.