of ore in pieces of the size of hazelnuts. Where no compact ore can be obtained, the fine ore may be cemented by being moistened, and then dried and broken. But the native compact ore is preferable, because it contains fewer impurities. Upon this layer of ore a layer of charcoal is placed, and then alternately ore and charcoal until five or six strata are piled. The whole is covered by charcoal of moderate size, firmly pounded. Fire is then introduced at the tuyere, and the bellows gently moved, so as to expel all the water contained in the mass, before a full heat for the reduction of the ore is given. When the water is supposed to be driven off, the bellows are urged more strongly, and the heat increased. The ore is then reduced, and iron liberated in a metallic state. The whole process lasts from three to four hours, at the end of which time twenty-five or thirty pounds of iron may be removed by tongs, and forged by means of sledge-hammers. Of course, the desirable shape is not produced until the metal is heated and reheated several times. After the iron from one heat is forged, the clinkers are removed, and another coating of charcoal thrown on; in fact, a renewal of the whole process is required.

In this process, none but the best kind of red iron ore, or specular iron is used; and it is questionable whether any but the richest of this ore can be employed. The iron manufactured is very strong and tenacious; from which the sabres of Damascus, and the neat and delicate, though very powerful Damascene gun-barrels, as well as weapons of nearly every kind, are wrought. In the States east of the Mississippi, no ore—or at least no ore in large quantitysuitable for the manufacture of such articles is found; but it is probable that it may be obtained in Iowa, Missouri, and along the borders of the Rocky Mountains. In Arkansas, large deposits exist. This ore is seldom found anywhere else than in transition clay slate, or roofing slate.

II. Catalan Forge.

This forge is extensively employed in Vermont and New Jersey, to smelt the magnetic ores of these States. It is there called the blomary fire. The form of this fire is nearly uniform everywhere. Fig. 73 represents a Catalan fire, seen from above. The whole is a level hearth of stonework from six to eight feet square, at the corner of which is the fireplace, from twenty-four to thirty inches square, and from fifteen to eighteen, often twenty, inches in depth.

Inside it is lined with cast iron plates, the bottom plate being from

Fig. 73.

Ground-plan of a forge fire.

two to three inches thick. Fig. 74 represents a cross section through the fireplace and tuyere, commonly called the iron.

Fig. 74.

α

Blomary fire.

་ ་་་་

represents the fireplace, which, as remarked above, is of various dimensions. The tuyere b is from seven to eight inches above the bottom, and more or less inclined, according to circumstances. The blast is produced by wooden bellows of the common form, or, more generally, by square, wooden cylinders, urged by waterwheels. The ore chiefly employed is the crystallized magnetic ore. This ore very readily falls to a coarse sand, and, when roasted, varies from the size of a pea to the finest grain. Sometimes the ore is employed without roasting. In the working of such fires, much depends on the skill and experience of the workmen. The result is subject to considerable variation; that is to say, the result depends on the circumstance whether economy of coal or that of ore is our leading object. Thus, a modification is required in the construction either of the whole apparatus, or in parts of it. The manipulation varies in many respects. One workman, by inclining his tuyere to the bottom, saves coal at the expense of obtaining a poor yield. Another, by carrying his tue iron more horizontally at the commencement, obtains a larger amount of iron, though at the sacrifice of coal. Good workmen pay great attention to the tuyere, and alter its dip according to the state of the operation. The general manipulation is as follows: The hearth is lined with a good coating of charcoal dust; and the fire-plate, or the plate opposite the blast, is lined with coarse ore, in case any is at our disposal. If no coarse ore is employed, the hearth is filled with coal, and the small ore piled against a dam of coal dust opposite the tuyere. The blast is at first urged gently, and directly upon the ore; while the coal above the tuyere is kept cool. Four hundred pounds of ore are the common charge, two-thirds of which are thus smelted; and the remaining third, generally the finest ore, is held in reserve to be thrown on the charcoal when the fire becomes too brisk. The charcoal is piled to the height of two, sometimes even three and four feet, according to the amount of ore to be smelted. When the blast has been applied for an hour and a half, or two hours, most of the iron is melted, and forms a pasty mass at the bottom of the hearth. The blast may now be urged more strongly, and if any pasty or spongy mass yet remains, it may be brought within the range of the blast, and melted down. In a short time, the iron is revived; and the scoriæ are permitted to flow through the tappinghole c, so that but a small quantity of cinder remains at the bottom. By means of iron bars, the lump of pasty iron is brought before the tuyere. If the iron is too pasty to be lifted, the tuyere is made to dip into the hearth. In this way, the iron is raised from

cess.

the bottom directly before, or to a point above the tuyere, until it is welded into a coherent ball twelve or fifteen inches in diameter. This ball is brought to the hammer or squeezer, and shingled into a bloom, which is either cut in pieces to be stretched by a hammer, or sent to the rolling mill to be formed into marketable bar iron. a. A mixture of fibrous iron, cast iron, and steel-an aggregation of unavoidable irregularities-is the result of the above proThe quality of the iron depends entirely upon the quality of the ore. No opportunities are presented by which any skill or ingenuity can create improvements in this process. Poor ores can not be smelted at all; but rich ores, like those at Lake Champlain, or in Missouri, or even the hydrates of Alabama, may be smelted to advantage; the latter with a prospect of economy. In some countries, where much larger fires than the one we have mentioned are employed, balls of 200 or 300 pounds weight are produced; but such large masses cannot be worked with facility, and are always of inferior quality. It is not advisable to make, at one smelting, balls heavier than 100 pounds.

In Vermont, where the rich magnetic ores are employed for this kind of work, a ton of blooms costs about forty dollars. To produce this quantity, four tons of ore and three hundred bushels of charcoal are required. Wages of workmen per ton ten dollars.

6. An improvement upon the Catalan forge is the stück oven described in our third chapter. But little explanation is required to exhibit the connection between the two manipulations. So heavy are the masses of iron in the stück oven, that powerful machinery, as well as a large number of workmen, is required in working them. The salamander, when lifted out of the furnace, is cut into pieces of 100 or 150 pounds weight. These pieces are reheated in a common forge, or Catalan fire; a portion of the cast. iron melts out of it; and what remains is generally the best iron, and called the "blume," or flower. From this term it is probable that our English word "bloom" is derived. Sometimes the bloom is in part steel, according to the state of the furnace, and the kind of ore used; but, generally, it is fibrous iron. The cast iron which results from the reheating is worked, by the common method, into fibrous iron. So expensive is the operation in the stück oven, and so imperfect the iron which it produces, that this furnace is now generally abandoned. Both the Catalan forge and the stück oven are impracticable where ores containing less metal than forty per cent. are to be smelted. Any foreign matter in the ore is injurious.

Many ingenious contrivances have been devised to convert ore, by one manipulation, directly into bar iron or steel. These contrivances are local, and vary according to the quality of the ore, and the intelligence of the operator. They are not worthy of our notice; in our country, at least, they are of no practical utility.

III. German Forge.

The most successful method of manufacturing charcoal wrought iron is by means of the German refining forge, or the blomary fires. of Pennsylvania. These forges not only produce good iron at reasonable prices, but they afford all the facilities presented by differently constructed apparatus. Fig. 75 represents a section of

the German forge, in which the location of the hearth is shown. The hearth is lined with cast iron plates; the bottom is generally kept cool by a current of water circulating in pipes below it. Three or four inches above the bottom, there is a row of holes, through which the cinder is let off. Through the tuyere, which is hollow, a current of water circulates. Frequently, the back part of the hearth is raised, for the purpose of putting in hot air pipes, as shown