Charcoal Iron.—This term is originally applied to such iron only as had been prepared solely with wood charcoal, from the ore to the malleable and finished state ; but now the name of charcoal iron is given to malleable iron, the ore of which may have been smelted with coke, in the ordinary blast furnace ; and it acquires its distinguishing name from the circumstance of its being refined with wood charcoal. The process of refining, and also that of puddling, are per formed as one in a puddling furnace, wherein it "comes round to nature," combined with less impurities than by the common mode described. The bloom, when taken out of the furnace, is put under the heavy hammer, and brought to the form of a flat cake, when intended for sheet iron, in which state it is denominated stamped iron. The stamped iron is next broken into pieces, piled, heated, and again put under the hammer, which reduces it to a slab of about one hundred-weight. These slabs are used for a variety of purposes; but their chief application is by the manufacturers of tinned plates, who reduce the "charcoal slabs" to the required thinness preparatory to the tinning operation. (See TINNING.) When the charcoal iron is required for bars, it is treated in all respects in the same manner as in making of the very best chain-cable iron. Owing to the large quantity and expensive nature of the fuel employed, charcoal iron is much dearer than coke iron; yet, from its great toughness and uniformity of texture, it is always preferred by engineers in the fabrication of steam-engine boilers, and, generally speaking, for all the important parts of machinery that are liable to severe tension.
Re-manufactured Iron.—Worn-out and broken articles of iron, termed old iron, are collected throughout the country, and purchased by a class of tradesmen called dealers in marine stores, who sort them into three kinds for sale. The first is called "coach-tire," and consists of the old wheel tire of carriages, and other large pieces ; the second is called "nut, or scrap iron," and consists of nuts, nails, screws, holdfasts, hinges, and an infinite variety of little solid pieces; the third is called "bushel iron," and consists chiefly of very thin articles of iron, such as those which have been of rolled sheets or hoops. The last-mentioned is of the least value, on account of the great waste by oxidation, and the trouble attending it. The iron so collected and separated by the dealers is so considerable in and near London, that although a large portion of it is sent by the Grand Junction Canal to the works in Staffordshire, and another large portion of it is shipped on board the coal ships, in lieu of ballast, for the Newcastle works, still there is a sufficient supply for three iron works near the metropolis; namely, one at Wandsworth, another at Chelsea, and a third at Rotherhithe. The last-mentioned, called the King and Queen iron works, is a very old establishment, and the most considerable of the metropolitan works, the quantity of hoops and bars made there being from fifty to a hundred tons weekly: the quality, also, of the iron manufactured at this work (well known in the trade as King and Queen iron) is justly celebrated, which may be accounted for by these circumstances—nothing but old iron being used, the machinery being of the most improved kind, and a vigilant attention to the essential parts of the process. By the liberality of the proprietor, Mr. Howard, we have had an opportunity of inspecting this work, of which we shall give such a brief notice as will enable us thereby to complete our account of the manufacture of English malleable iron.
A number of poor women are employed in piling up the scrap-iron into balls, as they are called; but the form is that of a short cylinder, resembling in size and figure the crown of a man's hat, somewhat narrower at the top than at the bottom. A flat circular piece of sheet iron forms the foundation, and on that is raised the fabric, the larger pieces on the outside, the smaller in the inside, to fill up the interstices, and the whole as solid and compact as can readily be done. Care is especially taken not to put any little bits of brass or copper that
may be accidentally mixed with the iron into the piles, which would prevent the consolidation or welding of the mass; and, to encourage the vigilance of the pilers, they are allowed the copper and brass they may thus find as perqui sites. The balls are put into a reverberatory furnace, similar to the puddling furnace we have described : when brought to the proper welding heat, they are subjected to compression by a " squeezer ;" this is necessarily a very strong machine; it is composed of a fixed lower jaw, of great massiveness and breadth (about a foot of superficies) on which the ball is laid, and is operated upon by the motion and force of the upper jaw, which, being actuated by the engine, is opening and shutting during the process, and thus it chews, as it were, by half a dozen or a dozen bites, the great ball of iron into a suitable shape to be passed between the shingling rolls, whereby it is, in a few seconds, reduced to a short, very thick bar or bloom. This bloom is re-heated in an air furnace, and then it is reduced between the rollers to a bar, a plate, or a hoop, equal in quality to the "best iron" from pigs; but it is, nevertheless, the com monest iron made in this re-manufacturing process.
We have now to explain the mode of preparing the larger pieces of old iron before-mentioned for re-manufacture. A number of men and boys are employed in clipping, with large fixed hand shears, the old hoops into convenient lengths, and other old articles into suitable sizes, to be afterwards made up into bundles, called faggots. The wheel tire, which requires great force to cut through, is effected with a pair of shears worked by the steam-engine: the materials, as they are cut, fall into barrows, in which they are conveyed to the faggotting depart ment, where several men are employed in preparing the faggots at a stout bench, on which are fixed convenient little machines, for facilitating the operation. One of these is represented at page 782. a a is a stout bridge-piece, in the centre of which works the screw b, by turning the handles c c; d d are two forked bearers, in which are laid two soft iron bands e e, beaded to fit the square to the bottom of the bearers. On these bands is first laid a piece of wheel-tire f; on this tire, pieces of hoop and.other thin stuff are then evenly laid, which last are covered with another piece of tire g. Their crooked or curved forms prevent their laying so close together as is desirable; the turning of the screw, however, forces them together very compactly, as shown in the sketch. Thus held down by the screw, the bands e e are brought together and twisted, which holds them fast, and the faggot is completed. The screw is turned back, the faggot taken out, and others are made in like manner. The sizes of the faggots vary much, being proportioned to the size of the bar, or other article to be made of it. If not more than twenty or thirty pounds each, as required for making puncheon, butt, or vat hoops, or small bars, they are, after being duly heated in the furnace, at once rolled out into their intended dimensions. If the faggots are large, they are heated and shingled into blooms, which are again heated when required to be rolled out. It is the practice at these works, as well as others, to prepare large quantities of blooms, to be kept as stock; but there is a great economy in finishing the work by the first heat of the faggot, and this is facilitated by the quickness at which the rolls travel in making the lighter articles above-mentioned ; and when, as at these works, the rolling is effected by three rollers, one above another, by which the iron is rolled both backwards and forwards (as before explained), a very long bar or hoop is completed in little more than half a minute, and, consequently, while the iron retains a good heat.