Puddling

—The proce by which wrought iron is manufactured from cast, the material being known as forge pig. The puddling furnace is of the reverberatory type, its hearth having a cast iron bottom, covered or fettled with bull dog or mill scale. The pig is fed to the furnace with a charge of slag, and, as it melts, the slag forms a surface over it preventing oxidation; while molten, the carbon, silicon, etc., are absorbed by the fettling, this raises the melting point, and the iron begins to solidify into a pasty ma . At this point it is rabbled, or worked with iron rods, and the ma worked about to bring it into better contact with the ferrie oxide of the bed, which absorbs more carbon. The iron is then worked into blooms or balls, a spongy pasty ma , and removed from the furnace to the shingling hammer, where the slag is beaten out of it. After this operation, with the same original heat, it is pa ed through the rolls, forming puddled bar, which is also known, from its contained impurities, as muck bar.