lightning, brought popular opinion to the point to which it had already been slowly tending, and Mr. Fairbairn only expresses the general sentiment when he adds, "It is quite evident our 'navy must be entirely of iron.' Whether it is preferable to construct vessels wholly of iron, or to arm wooden vessels, at least 'their vital parts,' with iron plates, is a less important discussion; for it seems inevitable that for some time both methods must be employed. To some extent a similar compromise is forced upon the respective advocates of iron guard-ships and an iron sea-going fleet. If England is to maintain her supremacy on the seas, she must, as Captain Reed says, build vessels that can keep the sea. But if the citizens of London and Liverpool are to sleep soundly in their beds in time of war, they must know that there are stationed in the Thames and the Mersey guardships carrying armour which no guns of the enemy can penetrate, and carrying guns which no plates of the enemy can resist. Subsequent events have, in some degree, modified the opinions which were formed on the operations of the 'Merrimac' and Monitor;' and there is no doubt we have still much to learn. Mr. Scott Russell's iron target has been demolished at Shoeburyness, and the French artillerists have constructed a gun which pierces 4-inch iron plates at 1000 metres. In fact, the aspect of the case changes each time that the Ordnance Office and the Admiralty get a-head of each other— the one in perfecting the means of attack, the other those of defence. The Report of the Commission on Fortifications is grounded on the assumption that the ordnance will remain masters of the field - so far, at least, that guns will be pro'duced of a sufficient power to penetrate, at a considerable 'distance, the heaviest armour plating that is compatible with 'the necessary qualities of sea-going vessels.' And in the interests of peace and of England (we are proud to say that in the unaggressive position which England assumes these interests are identical), it is to be hoped the ordnance may ever maintain its supremacy. For the guns which nominally represent the power of attack, do in fact measure the power of resistance to the aggression of an armour-plated invader.

We meddle not with the question of national defences, farther than regards the quality of the material; but this is a part of the subject to which much too little attention has hitherto been paid. It may not perhaps be fully proved what is the limit of the weight of armour which may be put on a sea-going vessel: this is a nautical question. But still less is it ascertained what power of resistance can be imparted to a plate of given weight and thickness: this is a manufacturing question,

It is

and in fact depends mainly on the quality of the iron. now a race between the nations of the world which shall first get an iron-clad fleet. It is quite as important, though less obvious a matter of rivalry, which shall secure for its fleet the best iron, for on this point the victory will ultimately depend. In a state of rapid transition from one mode of warfare to another, involving a change in the art of war hardly less complete than that occasioned by the introduction of gunpowder, it is inevitable that the Government departments must often be compelled to do and to undo, in order to maintain that naval superiority which is the condition of our national safety. They have no alternative. They must adopt the discovery of the day, and take the chance of its being superseded on the morrow; but this chance of having to do their work twice over, becomes a certainty if haste or any other kind of pressure prevents their securing the best materials in the first instance.

The great need of the day then is good iron; and it is acknowledged to be so by the Government, who have appointed a Commission to inquire and report on the subject. But that it is no longer an easy matter to find good iron, every man's daily experience tells him. If he goes into a hardware shop, he probably hears some complaint of modern iron. If he takes up a newspaper, his eye is caught by the account of some accident by sea or by land which is laid to the charge of iron. If his railway dividends decline, the necessity of prematurely replacing the rails which had been made of bad iron bears the blame. In short, it is generally felt that notwithstanding all our boasted improvement, some deterioration of the manufacture, or some demoralisation of the trade, has taken place and our anxiety to check this growing evil is painfully increased when we find that the national safety is staked on the quality of our iron.

The subject of the iron manufacture thus becomes of interest to many who had hitherto been repelled by its complexity and its technicalities; but it is less difficult than it appears at first sight, and by the exertion of a little patience, it will be easy to unravel one by one the threads of which the tangled tissue is combined- -so far, at least, as to form some notion of the nature and extent of the evil, and of its remedy.

Let us take up one of the price lists which are published from time to time for the guidance of manufacturers and dealers. It is very vague and is not intended to give information to those unacquainted with the trade, but it will serve as a string on which to hang our explanations. The first distinction it marks is between pig iron, the raw material, and wrought,' or

finished iron. But in the list before us is mentioned a third state, 'puddled' iron. This is half-manufactured iron, and in ordinary times it is not included in the price lists, because it is needed for his own use by the manufacturer who makes it, and none of it is to be found in the market; nor should we perplex the reader by noticing it, but that there is a probability that Government may become a considerable purchaser of iron in this intermediate state. If pig iron is compared to flour, wrought iron will represent the loaf, and puddled iron is the dough. Dough is not usually an article of commerce, but if a demand were raised for it, the supply would not be lacking. Pig iron is next classified according to its uses. There is a column headed, for foundry purposes,' and another, 'for forge purposes.' This diversity is caused partly by the different property of the ores, but mainly by the difference of the fuel and of the treatment. The fluid iron needed for the foundry is produced by diminishing the burden,' as it is called, of the furnaces; that is to say, by increasing the proportion of the fuel to the mineral, and thus impregnating the produce with a greater amount of carbon: hence the foundry iron being the most costly to make, bears a higher price in the market than the forge iron, made with the same materials and by the same mode of manufacture, and in that sense is better, but in no other.

The next distinction is between the hot and cold-blast iron. The existence of such a distinction has only lately been made known to the general reader; its nature is little understood, and as the explanation of it involves much that should be popularly known respecting the iron trade, it deserves our careful attention. The effect of this new and powerful agency, the hot blast, will be readily understood by the reader who remembers (as who does not?) to have passed many a quarter of an hour at a foreign inn in blowing his wood fire. He must have observed that where the blast of the bellows strikes the embers, it produces a black spot, and at the place and for the time checks combustion: of the same nature is the effect of the cold blast on the smelting furnace. But by previously heating in an oven to a very high temperature the air which is blown into the furnace, a prodigious increase of combustive power is obtained. The credit of this invention is due to Mr. Neilson, of Glasgow, who took out

It is not necessary to embarrass the reader with the mention of malleable castings made from charcoal pig iron, and annealed by means of domatile.

VOL. CXVI. NO. CCXXXV.

Q

a patent for it in 1829, and by this means raised the iron manufacture of Scotland to its present important position. The coal usually employed was so unfit for coking that it lost 55 per cent. in the process. It was now sent to the furnace in its raw state, and less than a third of the fuel proved to be sufficient. It was found that the hot air expelled to a certain extent the noxious properties from the coal, which the process of coking had hitherto been employed to overcome, and in many districts it rendered available materials, some of great value, such as the incombustible anthracite, and some, on the other hand, of very inferior quality, all of which it had hitherto been inexpedient or impossible to employ in the making of iron. This discovery, as it slowly travelled southwards, brought timely aid to those parts of the old districts where the best fuel was becoming scarce, and it brought into general use a vast quantity of new mineral, and even a new material. On looking over the price list we see certain kinds of iron distinguished as cinder iron' and all mine' respectively. Cinder is the refuse of the puddling forge, containing a considerable percentage of iron in combination with the impurities which have been expelled from the pig iron by the process of puddling. The power acquired by the hot blast of extracting from the 'cinder' this iron is equivalent to the discovery of a new ironstone supplied for nothing; but the produce is much deteriorated by the admixture of this material. It is known as 'cinder iron.' All 'mine' is an assurance that no such deleterious ingredient has been admitted.

Of the two classes of ironstone which are found in connexion with the coal measures, the argillaceous or the clay ironstone, and the carbonaceous or the black band,' the former only can be worked extensively by means of the cold blast.' It is the most generally useful of all the British irons, and when a tough fibrous quality is required this one is indispensable. It alone produces iron which has the greatest of all merits, that of being neither red short' nor cold short;' that is to say, not being brittle either when red hot or when cold. It is found in many parts of England, Scotland, and Wales, but the chief seats of the old iron trade were South Staffordshire, Shropshire, and parts of Wales. The black band was at once brought into general use by the hot blast. It is chiefly found in Scotland, North Staffordshire and South Wales. It supplies a vast amount of valuable iron, at a very cheap rate; but the produce has the defect of being cold short, and is not fitted for purposes where great strength and toughness are required. Of the ores not found in connexion with coal, the hæmatites, so called from

their blood-red colour, are the most important. They abound in many parts of the country, but especially near Ulverstone, Whitehaven, and in the Forest of Dean. The hæmatite iron is of very superior quality, but it has the defect of being red 'short.' It should not be employed where much manipulation is to be undergone. Its chief value is for the new processes of steel, and for tin and black plates.' Some of the hæmatite ores have been worked from very early times; but they have been brought into general use only by means of the hot blast, and the increased facilities of traffic, which gave them what nature had denied, a ready connexion with the fuel needed to smelt them. It is singular that the discoveries of iron ore in the Cleveland or Middlesbro' district took place just when the complete development of the railway system and the general use of the hot blast made it most available; and so rapid has been the rise of this district, that already its produce more than equals that of the old South Staffordshire manufacture. The ores are of unknown, and for all practical purposes, of boundless extent; the produce is a valuable iron suited both for forge and foundry, but not of a tough quality. The Northamptonshire ore is of the same geological character, and of a somewhat similar quality. It has a tendency to red shortness, but the ore is in great request with the iron masters who make much use of cinder,' the defects of which it in some degree corrects. These are all the varieties of British iron which for practical purposes we need notice at the present time. From them is derived the supply for the prodigiously increased production of iron, which has acted reciprocally as cause and effect of the rapidly expanding civilisation of modern days. Between the years 1840 and 1860 the make of iron was actually trebled; in the former year it was a little less than 1,400,000 tons; in the latter it exceeded 4,150,000 tons. But the reader will have collected from the brief account we have just given of the ironstones recently brought into general use that they do not supply iron equally available for all purposes, and that they especially fail to produce the best tough fibrous iron. It might, therefore, be anticipated that in spite of the great increase of production generally, the supply of this particular quality of iron would be insufficient, even though it were assumed to be still as considerable as it was before the new ironstones were introduced. But this, unfortunately, is far from being the case. Many of the manufacturers of the old district have been induced, or have been forced, in some instances by the exhaustion of the best materials, but more generally by the pressure of competition, to avail them