Two ient branch over his head. loops underneath the geer, in which he inserts his toes, serve as treddles; and the shuttle, formed like a large netting-needle, but of a length somewhat exceeding the web in breadth, he employs also as a "batton," using it alternately to draw through the weft, and strike it up. There is no beam to the loom; but the cloth is laid out on ground, the whole length of the piece. It is on this account that weavers are obliged to carry on their work out of doors, and to live in villages; building their houses beneath the shade of the tamarind, and the mango tree. The reed is the only part of the apparatus, that approaches in perfection the instruments we use. It is with this rude, and ill constructed loom, that the Indian produces those muslins, which have long been such objects of curiosity, from the exquisite beauty and fineness of their texture, so as when spread on the to resemble the web of the gossamer. It is not every one, however, who is capable of producing these fabrics; such a dexterity and slight of hand being required, which few out of the multitude are capable of acquiring. grass Notwithstanding the superiority of the people of India in this art, it has had no effect in improving the condition of the people. It does not even afford the capital necessary to its own existence, the funds which keep this branch of industry in motion being supplied not by the master manufacturer, but by the East India Company, the purchaser of the goods. Common muslins are made in every village of the Peninsula. It is at Dacca that those fabrics are produced of such exquisite fineness as to realize the idea of the poet of "webs of woven wind." The long cloths and fine pullicates are made chiefly within the presidency of Madras; the coarse piece goods and pullicates at Surat; the finest calicoes at Masulipatam, and tablecloths at Patna. Before concluding this account of the Indian cotton manufacture, it may be mentioned that of late a revolution has taken place in our trade with that country. The introduction of machinery has enabled us to reduce the price of our manufactures so much that we are enabled successfully to compete with India goods in those markets which formerly it exclusively supplied, and even export them to India itself. At the commencement of our intercourse with that country, our home investments were principally manufactured produce. Now, however, it is made up of the produce of the soil, such as indigo, cotton, raw silk, &c. We can easily imagine how materially such a change must operate on a crowded population, which has ever been a great manufacturing and exporting community. As to the cotton manufacture of China, the only goods of that description exported by the East India Company are nankeens and a few chintzes. The tint which the former of these has, naturally belongs to the cotton of which it is made, and is not given by artificial means. As for the Chinese themselves, about 9-10ths of their immense population are clothed in cotton. It is usually worn coloured, white being the dress worn during seasons of mourning, and on no other occasion. In our next essay we shall bring down the history of the cotton manufacture from its introduction into Europe, to our own times, noticing as we go along each invention and improvement. wwwww ON THE SMELTING OF IRON ORE. Read before the Glasgow Philosophical Society, by Mr. J. B. NELSON, Engineer. [Communicated by the Author.] Mr. PRESIDENT,-This wellknown metal, on the smelting the ore of which I mean to make a few observations, is decidedly of all others the most useful and the most. indispensible to man, and is more generally and more abundantly dif fused throughout nature than any other. Under a variety of forms, it is found in the earth, combined with numerous other substances, both earthy and metallic. The waters of many springs are impregnated with it. It is present in a great many vegetable products, and is found in their ashes after they are burnt. Very few fossils are free from it; and it is the principle on which their colours generally depend. It is a constituent principle of the blood, and of several other animal fluids and solids. A considerable difference of opinion has prevailed among mineralogists with regard to the existence of native iron, which, at any rate, is scarce. It has been found, however, in masses, in Siberia, and in the internal parts of America; and, very lately, a large mass of native iron was found in Louisiana, which is now in the museum at New York. There can be no doubt, however, that these masses are of the same nature with those which, it has been established on the most ample and positive testimony, have fallen from the atmosphere, in different countries, at various times. Whatever, therefore, may have been the origin of the meteoric iron, the masses of Siberia and of America, there is every reason to believe, had the same origin. Native iron, in a malleable state, has been likewise Isaid to have been found imbedded n some iron ores in Saxony; but of this there still remains considerable doubt. It is not very easy to say when the first knowledge of iron was obtained, or what first led to it; but it is not at all improbable that it arose from the discovery of some of these meteoric masses which had fallen from the atmosphere. The capability which the iron in these masses possess of being hammered into shape, may have first led to a knowledge of the valuable proper-ties of that metal, which has since become so important to mankind; and which has tended so much to the advancement of every useful and every elegant art. Tradition, which, however, lends but a feeble ray to light us in any attempt to penetrate the darkness which envelopes our knowledge of remote ages, has informed us that the discovery took place accidentally in Greece, in consequence of the burning of a wood; and when we consider how accidentally the first knowledge of many things the most important to man has been obtained, this is certainly not improbable.We know that iron ore is to be found on the surface of the earth; and the intense heat created by the burning of a forest may have melted the ore, and left among the ashes portions of iron in a malleable state. It is equally probable, however, that it may have been first obtained in the course of the process of making charcoal; masses of iron ore intermixed with lime may have been in the covering matter of the charcoal; a portion of this may have fallen among the ignited fuel; an increased current of air may have accidentally arisen, thereby causing a heat sufficiently intense, and while the charcoal would be destroyed, iron would be brought into existence. The similarity of the substance thus obtained to meteoric iron, would lead to the experiment of applying it to similar purposes: and the benefits thus unintentionally obtained, would lead, with a view to beneficial results, to a repetition of that process, which, when it first accidentally occurred, was considered as a calamity. If we are in the dark with regard to the discovery of iron; we are equally so as to the furnaces at first used in smelting it; and it would be ridiculous, as it is impossible, to say what was the form or shape at first used. But, if the conjectures which have been advanced, be grounded in truth, we may presume that a knowledge of the air bloomery furnace, which is the earliest we know of, may have thus arisen. It appears, indeed, for a long period, to have been the only form used: in Spain, and on the shores of the Mediterranean, it is still used, where Elba ore is fused to a considerable extent. Although there is reason to be certain that furnaces on this construction existed in our own country, nothing is known either of their plan or of their extent. One of our most eminent African travellers, however, gives us an account of those he saw in use in Africa: he describes them as conical, of narrow limits, small opening for admitting the air, and for allowing the combustible products to escape. The ore used in these furnaces required to be very rich in order to give beneficial results. The iron is produced by the deoxidation of the ore, which takes place by its being in contact with ignited charcoal; and till the metallic particles of iron begin to be separated, it must be kept as much as possible from the contact of air; and an in creased temperature is then necessary to unite the metallic particles into masses. These masses, which, when taken out, are combined with its earthy parts in a state of scoria, are then hammered into blooms, and afterwards they are reheated, and hammered into the different forms necessary for the purposes to which they are intended to be applied. This process would be attended with uncertainty, and from the changes of temperature and season, at times would not go on at all.— When it was necessary for the temperature to be increased to unite the metal into masses after deoxidation, the current of air might fall off, and thus stop the process from going on. This would lead to some means of producing a regular and increased current of air; and the first appli cation of the bellows to this de sign, is a very important step in the progress of this art. It is probable that when first used, they would only be applied in the second part of the process, in order to produce the heat necessary to combine the metallic particles into masses; but time and experience would lead to the knowledge of the important advantages to be derived from the use of the bellows, though these must have been the result of labour and perseverance-the nursing parents of improvement. The blast bloomery furnace which came next into use, must be considered as a most important revolution in the art of making iron; and as having been of incalculable advantage to mankind. In the airbloomery, the ore being in contact with the charcoal was deprived of its oxygen, and afterwards, as we have stated, by the influence of an increased temperature, was run into ductile iron; in the blast-bloomery, however, not only was the ore deprived of its oxygen, but by the uniform and increased temperature, occasioned by the blast, the iron combined with the charcoal, which would produce fusibility, and crude cast-iron, now so much improved and so wonderfully employed in the aggrandisement of our country, would be produced. The soft and ductile iron produced by the air bloomery, would, by this process, disappear, and a fluid metal would be the result, perfectly different in its properties from the other, and which would go to pieces under the hammer. This result, so different from what would at first be expected, would often have the effect of causing the bellows to be laid aside for a time, until chance, or some more intelligent smith than another, would find, in the course of frequent attempts to hammer this iron, that it in time got better. It would soon occur, or be discovered, that directing the blast down upon the surface of the metal while it was yet in the furnace, would have the same effect, and would, therefore, shorten the method of obtaining the ductile instead of the cast iron. Thus a new form of furnaces would be constructed; and hence resulted the blast-bloomery. The blast-bloomery furnaces in this country were either square or round, and from three to four feet high. Although the waste of ore was not so great as in the air-bloomery, yet the blast-bloomery was very imperfect, and there was still a very considerable waste. The amount of this may be estimated from the quantity of iron still remaining in the slags, found in this country, and known by the name of Roman or Danish cinders, which were the product of blast-bloomery furnaces; these slags contained on an average 40 per cent. of iron, and were used extensively for a considerable period as ores in the blastfurnaces of this country. The next step in improvement in the art of making iron, was the blast-furnace which is now in use; and from which foundries, forges, and finery-furnaces must have re sulted. Great benefits have arisen from the use of the blast-furnace;' from the continued process of re duction, a complete separation of the iron from the ore is effected, thus giving a greatly increased quantity of iron in a far less time, and with less expense of fuel; and by having received a greater doze of carbon, it becomes more fluid, falls below the blast, remains in the bottom of the furnace, whence at particular times, it can be run into pig beds made in the sand. By this additional doze of carbon, how ever, it would be found to be quite unfit for the hammer, or be made into blooms; but as a particular direction of the blast, in the blastbloomery, was found to render the metal ductile, this principle could be applied in the new mode of manufacturing iron. It would immedi ately appear, that this operation could be performed in another furnace, without having any connection with the previous smelting. This would lead to the erection of the finery-furnace, where the crude iron goes through the process of decarbonization, from which it is taken to the puddling-furnace, where this process is completed. . It is not exactly known when the blast-furnaces were first introduced into this country. No facts exist even in Dean Forest, the most ancient place for making iron in Britain, as to this: neither is it known whether it is a native invention, or one imported from abroad. In James the First's reign, the iron trade is said to have been extensive; however, it fell greatly to decay afterwards, owing to the want of wood. In Queen Elisabeth's reign it must have been very extensive, owing to the quantity of heavy ordnance then in demand. The dissensions between the houses of York and Lancaster must have tended to injure very much improvements in science, during the period they subsisted. It is, however, supposed that the blast-furnace was used in the reign of Henry the Seventh. The sites of them are found near small streams, for the purpose, it would appear, of obtaining water power for the bellows. The scarcity of wood would lead their attention, no doubt, to obtaining a substitute likely to supply its place; and pitcoal would appear to be the only one. In the time of James the First, many patents were granted for making iron with pit-coal, but these attempts, it would appear, had failed. Other patents were granted in the reign of Charles the Second, but it appears that it was not until about the year 1750 that pit-coal became a complete substitute for wood char. These attempts, no doubt, failed from the blast not being powerful enough; this was overcome, however, by the advancement of science, and as hand bellows gave place to those driven by water, this in its turn gave way to the steam engine, that most powerful agent in the hands of man. Having thus traced the manufacturing of iron from the period of traditional uncertainty, through the many stages it has gone, to the present day; and having traced its progress from the making of ductile iron to the advanced state in which the art now is, I have more particularly to direct your attention to the subject of the present essay, which is as to some of the defects at present existing in the making of the pure carburet of iron. We must admit that, with all the skill which we possess, derived from experience and from scientific research, and notwithstanding all the advantages and knowledge we possess over our forefathers, we are still ignorant of the cause of many disadvantages and imperfections which a number of the most important of the arts labour under, and, consequently, we are unable to make any attempt for their removal. Notwithstanding the progress which has been made in the art of manufacturing iron, those acquainted with it, know there are still many imperfections to be remedied, and many disadvantages to be removed, could the cause of them be completely ascertained. Long experience has shown, that furnaces for smelting of iron ore into pig-iron, produce, during the summer months, far less iron, and that of an inferior quality, in the same given time, with the same power and an equal quantity of ore, than they do in the winter months. As to the cause of this, I have formed an opinion, you will observe, rather different from the one generally entertained. It has been said to arise from sulphur in the air, in the summer months; and I, having been asked, if it was not possible to purify it, as we do carburretted hydrogen gas, was led, from this, more particularly to investigate the subject. I was soon, however, convinced that this was not the cause; and I think the real cause has never yet been pointed out. I need not explain to you how powerful an agent throughout nature oxygen is, nor need I mention how necessary it is to animal life, as well as to supporting combustion. These are matters with which you are perfectly familiar. But what I have now to suggest is, that the cause of the imperfection I have mentioned in the smelting of iron ore, is the want of a due proportion of oxygen, in the air blown into the furnaces during the heat of the summer months. It is quite |