be made superior, in every respect, to that manufactured from the

best metal.

VI. General Remarks on Charcoal Forges.

It is undeniable that charcoal forge iron is, in many respects, superior to puddled iron. For all the purposes for which wrought iron is applied, it is more malleable, compact, and durable. The puddling process is conducted on more philosophical principles than the charcoal forge, and in the course of time may be brought to such a state of perfection as to supersede the latter altogether. But this is not the case at present; and the charcoal forge will be needed so long as the puddling process does not furnish a quality of iron equal to it. Another reason why the former will command precedence for some time to come, is that it is less expensive than the more complicated puddling establishments, and permits the manufacture of iron on a small scale without serious disadvantages. Iron works, situated at remote places in the country, frequently find a favorable market for a limited quantity of iron; while an increase of that quantity would not prove profitable. Such cases are very common in the farming districts of the interior of the country which are not easily accessible, as well as in the growing Western States. The same remark is applicable to the new States and territories. It is questionable whether the charcoal forges of the West, and even in the heart of the anthracite and bituminous basin, do not yield larger profits than the puddling forges and rolling mills; at least, an investment in charcoal establishments may be considered quite as safe as in those of stone coal, at the present time.

a. The location of charcoal forges should depend upon the supply of ore and wood. Inferior ore, and the metal smelted from it, are less useful to the charcoal fire than to the puddling furnace. The success of the former depends upon the quality of the metal with which it is supplied. It is thus evident that the best is always the cheapest metal. This rule is not applicable to puddling establishments. In addition to this, the charcoal forge requires good coal. But rich ore or excellent metal may counterbalance expensive coal; while poor metal and expensive coal will yield only unprofitable results. Where the metal is good, a ton of iron requires only 150, and sometimes only 120 bushels of charcoal; and seven tons can be produced in a week, with but one fire. But where it is poor, a ton will require from 200 to 300 bushels; while only two or three tons of iron per week will be produced. We refer to blooms, not

to drawn iron. Consequently, should the iron resulting from the smelting of good or bad metal be equally valuable, which is not a fact, the expenses of manipulation are so decidedly in favor of the former, that the question which to choose will never arise.

b. The magnetic ores of the States of New York, Vermont, New Jersey, Missouri, afford an excellent article for the charcoal forge. These ores exist in such immense quantity, and in the north-west part of New York are of such superior quality, that the little interest they excite in the public mind is to us a matter of extreme astonishment. In the magnificent region just mentioned, metal might be made at the ore banks, and sent to the Hudson or the Delaware River to be puddled. The spathic carbonate, the specular ore, and the red clay ores of the transition series, also constitute an excellent article for the charcoal forge; but these are not so generally distributed as the magnetic ore, at least, they are not concentrated in such large masses at any given place. The rich hydrates of Tennessee and Alabama are adapted for the Catalan forge. The same reasons which may be assigned against the working of poor ores in this forge, apply against their use in the charcoal blast furnace. Inferior metal is, at present, employed in the coal regions for the manufacture of charcoal blooms; but we predict that these efforts will, in a short time, be abandoned, because poor charcoal iron cannot successfully compete against puddled iron. Metals which contain phosphorus or sulphur are not adapted for the charcoal forge, because of the inferior iron they produce, and because of the amount of time consumed in converting them into bar iron. Gray metal from rich ores, and mottled or white metal of pure origin, form medium qualities. All metals derived from impure bog ores, sulphurets, silicious ore, and ores containing phosphorus; all the gray metals smelted from poor ores, particularly those of silicious origin; and all white metal resulting from small burden, inferior ore, and bad management in the blast furnace, are improper for the charcoal forge.

c. The necessity of good metal in the forge is illustrated by the following fact: An instance is recorded in which a ton of blooms, from white metal of excellent quality, was produced, with the consumption of only ninety bushels of coal; while, on the other hand, when gray pig iron was used, 400 bushels of coal were consumed in producing the same amount.

d. The site of a forge is generally selected in relation to facilities for obtaining water power; but it is probable that steam may

prove to be the preferable power, because the waste heat of the forge fire is sufficient to generate it. It is also probable that the first outlay in erecting the works is, at least in a majority of instances, in favor of the steam-engine.

e. The application of hot blast to the charcoal forge is of questionable advantage. It will save fifteen or twenty per cent. of coal; but labor is increased, and the iron depreciated. We shall elsewhere make some additional remarks on this subject.

VII. General Remarks on Puddling.

This method of converting cast iron into malleable iron is designed to supersede every other method by which that result is effected. But, thus far, the quality of puddled iron has been such that we have been unable entirely to dispense with the charcoal forge. Still, this quality would be much improved if better metal was generally employed. The nature of the puddling process is such, as we have elsewhere stated, that we are enabled by it to employ inferior metals to a great degree. Thus, blast furnaces have been erected at places where charcoal forges would not have flourished. Inferior pig iron answers tolerably well for the puddling furnace. Metal perfectly useless in the charcoal fire will, in this furnace, produce a very good article. In fact, every kind of pig iron, however bad in quality, may, by the puddling process, be advantageously worked.

a. In the Western States, where charcoal pig alone is puddled and boiled in single furnaces, iron of very good quality is made. A great deal of inferior iron is also produced, which, according to the metal used, should be of better quality. The puddling furnaces of the West work well; but it is doubtful whether a due amount of labor is spent in working the iron. The puddlers generally finish a heat in less than an hour and a half, including shingling; and the boilers in less than two hours. At other places, this is considered an insufficient time to do full justice to the work. At well-regulated Eastern establishments, twelve hours are consumed for five boiling heats, and the same time for six puddling heats. This may be considered fair time for industrious and judicious manipulation. Where the metal is of superior quality, less attention is required. But throughout the United States the tendency of most blast furnaces is to produce gray metal; consequently, the manufacture of good bar iron requires great industry, however good may be the ore from which it is smelted.

b. As previously remarked, at Pittsburg and the Western Works, boiling is carried on in about one-half of the puddling furnaces. Those used exclusively for puddling are regarded as necessary evils, and are employed merely to make cinder for the boiling furnaces. Excellent cinder is produced from metal of good quality, carefully puddled; but, on account of the refining of the crude iron before it is taken to the furnace, this operation is expensive. All the advantages which the process includes are realized at the Western establishments. But, unless other methods are adopted by the Western manufacturers in working pig metal, competition will gradually exhaust all the profits of this business. This, let us observe, is a more important matter than it seems to be, for, if puddling is replaced altogether by boiling, the question meets us, whence is the necessary supply of cinder to be obtained? Charcoal forge cinder, at present frequently applied, cannot be obtained in sufficient quantity. Artificial fluxes, then, are the only resource of the Western manufacturers. Good iron ore will serve as an excellent flux; but this cannot be found either in the Western or in the Eastern coal regions. In the State of New York, the magnetic ore from Lake Champlain is employed; and the furnaces of this State not only produce excellent iron, but furnish a more abundant yield than any we have ever seen. At Saugerties, on the Hudson River, 2000 pounds of rough bars have been made from an amount of pig iron varying from 2075 to 2100 pounds. Loss only from three to five per cent. Amount of anthracite coal consumed from 1600 to 1700 pounds. Furnaces double, with iron air boshes; charge 750 pounds, and five heats in twelve hours.-The magnetic ores of Missouri, and the red oxides of Arkansas afford a good material for the Western mills; but ores of the coal formation are not sufficiently pure. The amount of good ore required per ton of inferior pig iron is sometimes from 400 to 500 pounds; but for excellent metal, rarely beyond 200 pounds.

c. We have stated that most puddling furnaces are provided with iron boshes. But in those which work anthracite iron, soapstone is employed for keeping the boshes in order. It is evident that, if iron boshes were proved in all cases to be advantageous, they would be adopted. But, in the present case, they are of doubtful utility, as we shall explain.

The necessity of enlarging the hearth, so that a smaller surface of the boshes, in proportion to a given amount of metal, would become cool, originated the double furnace. It was found that the

The

cooling influence of the iron lining, in small or single furnaces, was so great that inferior pig iron could not receive that improvement which otherwise might be effected with comparative ease. extension of the area of the hearth, to a great extent, removed this difficulty. There is no doubt that the quality of iron might be improved to an inconceivable degree, if a hearth could be constructed of materials adapted to resist the action of strong alkalies; but the necessity of cooling the boshes is so strong a counteracting element, that the beautiful theory of improving iron by means of artificial cinder is but of limited application. In this respect, double furnaces present greater advantages than single furnaces; and boshes cooled by air are superior to those cooled by water.

In the improvement of bad pig iron, by puddling, our primary object should be to melt it perfectly, and then to remove its impurities by means of cinder. If, therefore, a hearth is so cold as to prevent the melting of the metal, the most essential condition of improvement is not realized. If the iron contains impurities firmly and intimately combined-as that from coke, anthracite, or even from charcoal furnaces, smelted with small burden-a perfect remelting is necessary. Such iron requires a strong heat; and this heat cannot be produced in a furnace with cooled boshes. Hence the failure of experiments made to improve such iron. Anthracite iron contains a large amount of silex, in addition to carbon; and a furnace with water boshes is unable to produce a heat sufficient to melt it. Fibrous bar iron is preferable, as an article of commerce, to that which is cold-short; and to prevent it from becoming coldshort, the intimate connection between the impurities and the iron must be destroyed. Therefore, a furnace with soapstone, or, what is still better, good fire brick, will produce a better iron for the market than a furnace with cold boshes. A uniform temperature of the lining and walls is required to produce a thorough solution of the pig iron. The presence of silex in large amount, as in a lining of soapstone or fire brick, affords by retarding the work, every facility for producing this result. This latter circumstance should be viewed rather as the least of several evils than as a positive advantage.

From these considerations, it follows that pig iron from small burden, or made by a high temperature in the blast furnace, cannot be improved in a furnace with water boshes; and that the application of these boshes should be limited to such iron as will thoroughly melt at a medium heat. Consequently, white metal containing a