IMPROVED FORGE AND BLOOMERY.
The forge here presented is rather novel in construction, and is a combination of several well-known processes. The chief feature of the Catalan forge is preserved,— . that is, the hearth, which does not differ much from the hearth of the blast-furnace; but here the deoxidizing is performed much the same as in the blast-furnace, by the waste heat which escapes in the common forge.
This forge is double, and contains not only two hearths, but a reheating apartment, so that three sets of men can operate at the same time. The escape-heat from the bloomery also passes through the deoxidizers, and helps to sustain the heat in the hearths.
The ores being thoroughly deoxidized descend to the hearth ready for fusion before the blast, and here the heat is very great and the reduction rapid. Cinder is allowed to partially cover the loup; and while the ore is constantly added to the glowing mass above, the iron as constantly adds to the loup in the bottom of the hearth.
When the loups are withdrawn, they are turned over to the hammer-men and re heaters, who convert them into blooms, and reheat and draw them into bars, while the forge-men continue the production of loups. By this process, ten loups, of two hun dred pounds each, can be produced by each hearth in ten hours, or from four to five thousand pounds of iron can be produced per day by one of these improved forges and bloomeries with ten hands; while the saving in fuel is much greater in proportion than the saving of labor.
In the common Catalan forge, 100 pounds of iron from 50 bushels of charcoal is con sidered a good yield: it often happens that double this amount is used in carelessly constructed forges. In the improved forge, from 15 to 20 bushels of charcoal will pro duce 100 pounds of iron; while from three to five cords of dry wood, according to the state of the weather and the condition of the furnace, are sufficient for reheating purposes.
Mineral coal of any character, provided it burns well, answers the purpose of wood for reheating, and a pure coke or anthracite.coal may be used in the hearth; but char coal is preferred if good iron is required.
These forges are much less costly than blast-furnaces and rolling-mills for the pro duction of bar iron; but they can be recommended only in localities where a small amount of capital only can be profitably expended, and where rich ores may be obtained, since no other kind can be successfully used. Magnetic oxides and pure hematites, or specular ores, are generally made use of. Lean or silicious ores, unless separated from their impurities, will not produce good iron in the Catalan forge.