myself acquainted with the natural advantages possessed by most of the coal-fields and principal iron ore deposits of the United States. From the information thus obtained, an attempt will be made to compare the resources possessed by different localities in the old and new worlds as iron-making centres. This object would scarcely be complete, unless the cost and efficiency of the labour at the disposal of the mine owner and manufacturer received some consideration. This last-named subject may involve questions of a character not so easily dealt with as the natural resources of the country itself. Such questions will probably occupy hereafter-if, indeed, they do not do so already-a position of considerable importance with regard to the interests of Great Britain as a manufacturing nation. In the matter of cost, viewed in the abstract, the Continent of Europe has undoubtedly the command of cheaper labour than is to be found in Great Britain. We shall be better able, however, to compare the relative economy of the two, when other elements, besides that of mere price, are brought into the account.

SECTION II.

HISTORICAL.

IT is certainly not essential to the main object of this work that the early history of the manufacture of iron should occupy any place in its pages. Nevertheless, a brief consideration of the various steps, by which the smelting of this metal has arrived at its present position, affords an opportunity for comparing the progress of recent years with that of preceding ages. Hence a section, historical rather than technical, may not be without its use as well as its interest.

Except in the form of those well-known meteoric masses, in which iron forms the chief ingredient, this metal, I imagine, was, until a comparatively recent date, unknown in its native state. Some years ago, Professor Nordenskjöld had heard of its existence in Greenland, and in 1870 he was fortunate enough to discover its source on certain islands in Davis Straits. It is there found as small detached masses embedded in Dolerite, a circumstance which accounts for its preservation in the metallic form. It is a remarkable fact that this native iron is usually associated with 2 or 3 per cent. of nickel and cobalt, in which particular it resembles the meteoric iron already referred to. The subject has been ably examined by my friend Dr. Lawrence Smith, of Louisville, Kentucky, who supposes that the heat of the fused basalt, and the presence of carbon as found associated with the metal, had effected the reduction of the original oxide of iron, frequently found in this igneous rock.

The absence of iron, in its metallic form, in many of the monuments of very remote antiquity, has led to the belief that its existence was unknown to the earlier inhabitants of our globe. In the numerous instances when objects anciently used for warlike or for domestic purposes have been discovered, they have generally been fashioned out of stone, or in more recent times out of bronze.

Tide "Annales de Chimie and de Physique," 5e serie, t. xvi., 1879.

In many instances, unquestionably, the absence of this metal may be set down to its perishable nature, prone as it is, under atmospheric influences, to rapid oxidation. Iron implements, protected from these influences, have been found in some recent explorations, and have proved that mankind was acquainted with the existence and value of iron at a much earlier period of the world's history than was at one time believed.

The minerals containing iron afford, it is true, but little indication of their metallic nature; but this is so easily rendered conspicuous by mere contact with burning wood, at very moderate temperatures, that accident alone must, where the ore is plentiful, have led to a knowledge of the valuable nature of its composition. Metallic iron being thus so easily produced, little ingenuity or skill would be needed to forge it into a variety of useful articles, greatly prized even amongst the least civilized communities.

The facility with which a portion of the iron is reduced, and separated from the earthy substances with which it is usually associated in nature, would doubtless lead to its production, even among savage nations, between which no intercourse existed. Colonel Grant kindly made a sketch for me of a primitive forge which he had seen in operation in the interior of Africa, upon the occasion of his discovery of the sources of the Nile, in company with Captain Speke. In this drawing, two natives, each working a pair of single-acting bellows, are seen urging the combustion of a small heap of charcoal situate midway between the two. The ore, in small pieces, is added from time to time, with fresh supplies of fuel; and this is continued until a mass of iron of the required dimensions is obtained. As may be imagined, a process carried on by persons destitute of all mechanical contrivances, save those of the rudest kind, could make no progress; and Colonel Grant supposes that the produce of the two men did not exceed a dozen pounds per day. On the other hand, a furnace differing but little from the rude hearth just alluded to, in the hands of more skilful mechanicians, can turn out as much as 300 pounds in the twelve hours.

In some parts of Europe this simple mode of making iron, performed in what is known as the Catalan Forge, is still practised, as it

has been for some hundreds of years; and in the United States of America as much as 30,000 tons are annually obtained by a process which is almost identical with that witnessed by Grant and Speke in Central Africa.

Whatever may have been the precise nature of the process by which in ancient times iron was produced, it is clear that the human race was early possessed of materials capable of forming tools of great hardness and power of endurance. It has been suggested that some forgotten method of tempering bronze, an alloy in common use, supplied the means of cutting and even carving the hardest kind of stone. It seems, however, equally probable that people capable of designing and constructing the monuments of Assyria and Egypt should have noticed that the process of making iron, in the rude hearth already spoken of, may be so conducted as to produce that partially carburized form of the metal known as steel. Indeed, it appears as if in later times the very same description of furnace was employed indifferently to obtain wrought iron, steel, and pig iron.

It would, at any rate, be hazardous in the extreme to ground any settled opinion upon the state of metallurgic art in ancient, or even in prehistoric times, by the state of our own more recent knowledge; for there is evidence which points to the belief that in some lands the art of making iron was, at a very early period, in a far more advanced condition than it had attained so late as the reigns of Elizabeth or Charles I. in this country. As an example of this, there is at Delhi an architectural column of very great antiquity, formed out of malleable iron; it is above 16 inches in diameter, and is calculated to weigh upwards of 17 tons. Its existence proves that subsequent to the date of its manufacture, a great decadence must have taken place in the art of working the metal; for I am not aware that there remains any later record of the existence in the Indian peninsula of the means of forging, in so perfect a manner, so large a mass of iron.

The hearth and Catalan fire-as the latter was called from its use in that province-blown by means of a fall of water known as the trombe, or by bellows, were the only means employed for ages in furnishing the world with the iron it required. We are, singularly enough, left to conjecture, not only when, but in what manner the next step in its

manufacture was brought about. This want of precise knowledge is the more remarkable, seeing that the change, consisting in the production of cast iron, has probably been effected within the last three centuries, and that it altered entirely the character of the operation in which it virtually constituted the first really great improvement.

Contemporaneously with the use of the Catalan hearth, at all events in later times, the Stückofen was worked in Germany, and the Osmund furnace was employed in Sweden, both being driven with compressed air. A mere addition to the height constituted all the essential difference between these two forms of furnace and their primitive predecessor. This change of construction would probably be suggested by an expected economy in fuel, or an increased production of metal, or by the hope of combining both these objects. It seems doubtful, however, whether the weight of malleable iron, or of "blooms," obtained by means of either description of furnace ever exceeded two or three tons per week.

The German Stückofen was usually about 10 feet high, but this was increased sometimes to as much as 16 feet, with a diameter at its widest part of 5 feet. The breast was built up temporarily with brickwork, which was removed when the bloom of wrought iron was ready for the hammer. It cannot be doubted that in such a form of apparatus cast metal would be occasionally formed.

This last-mentioned circumstance in all probability paved the way to the construction of the Blauofen, an invention for which we are likewise indebted to the German people. In it the height was sometimes as much as 25 feet, by probably 6 feet at the widest part. With such dimensions as these there would be no difficulty whatever, by proper treatment of the ores, in combining the metal with sufficient carbon to obtain a constant supply of cast iron; and there seems no doubt that by means of the Blauofen this was attained in actual practice. At the same time mere capacity will not of itself suffice for the production of what is now known as pig iron. If the ore and fuel were employed in such proportions that complete reduction of the oxide was rendered impossible, a substance containing little or no carbon would be the product, in whatever form of furnace the operation was conducted. Accordingly we find the Blauofen at one time used as a