CHAPTER IV.
ON THE MANUFACTURE OF IRON FOR GUN BARRELS.
A considerable progress in improvement has taken place in manufacturing the higher quality of iron since my last publication. Not that I arrogate to myself any credit on that score, but it is evident that good frequently comes of flagellations, whether on the body or the mind. One part of human nature will ever fear the exposure of bad qualities, while another is emboldened to advance in improvement if the slightest chance exist of success or encouragement. Thus we often see men striving to produce one invention on the back of another, with wonderful perseverance, finding many blanks and rarely a prize; for truly in this competing age, the mind must be strong that can fight long. Bitter is the disappointment of the truly ingenious mind, to see the produce of his brains thrown as lumber into the _herring barrel_,--as the printer terms the receptacle for what he sets no value upon; while the valueless contrivances of the mean and sordid are preferred and rewarded, because they enable the manufacturer to produce cheaper, by foisting on the public a deceptive or a spurious article. All inventions for purposes of deception, are readily, aye, eagerly, patronised; for they return gold to the coffers sooner.
The improvement in the manufacture of gun-barrels depends on the quality of the iron entirely; for it would be a useless waste of time to endeavour to make a good barrel of inferior metal. Science and experience have worked a wonderful change in the mixture of the superior qualities of iron: we have had announcements of silver-steel barrels at _ten guineas a pair_ in the rough, of Brescian steel barrels, carbonised iron, and I know not how many more descriptions or compounds of metals, to form the best material for high-priced barrels. We have now metal which, in the rod, cannot be sold for less than one shilling and twopence per pound: the iron for a pair of barrels thus costing sixteen shillings and fourpence. This is good; nay, more than good--’tis excellent. But there is a dark side of the picture, over which I would fain draw a veil: but I must not. Belgium, France, Holland, and Germany, are improving, are marching onward, and we, alas! are standing still. Competition and cheapness combined, are driving our gun trade into a labyrinth, out of which it will be long ere it finds the clue of exit. Our manufacture of inferior gunnery has certainly reached a depth of inferiority which never any other manufacture in the world reached, and I hope never will.
During the existence of the slave-trade, many thousand guns per year were made of what is, by the trade, technically termed “_park paling_,” a material only fit for such purposes; and the cost of it was only _seven shillings and sixpence_ each _spike_; but now we can furnish slave traders with ship-loads, if they choose, at only _six shillings and sixpence_ each, and it is still supposed that one of these _imitation_ guns is the blood-money for a fellow-creature. It would be a just and equitable law, if our legislature would pass it, “That every man should fire the guns he manufactures:” nothing would more surely tend to improve the quality of guns of a low grade.
A considerable increasing difficulty attends the obtaining of horse-nail stubs from the continent. In various continental markets from whence we draw our supply, the skill and ability of the gun-barrel makers have increased; and the preference for superior fire-arms which is gaining ground with many continental sportsmen, has taught foreigners the value of their old horse-nails; and hence their increased scarcity. The inferior iron of which we make horse-nails prevents entirely the use of our own; consequently it requires no foresight to predict that our manufacturers will soon resolve themselves into two descriptions--the very best and the very worst. The latter are already actively employed, and the others are advancing; as no doubt an increasing desire to obtain the most perfect gun pervades the thinking and affluent portion of the sporting world.
The manufacture of iron is a science truly worth the consideration of the philosopher, for it is fraught with the most important consequences, considered either as a material of commerce, or the means to an end. In advancing manufactures and the progress of improvement, it has had an effect on civilization unequalled by any known product, gold not excepted; for no substitute exists for iron, or ever did. No doubt the ancients had their bronze, of which they could form edge tools, even razors; but that was a very limited use of cutting tools: enough, perhaps, for war or subsistence, but not for the progress of the arts.
Of the first discovery and use of iron we have no record; though its value may be presumed from the fact, that Quintus Curtius mentions that “Alexander of Macedon, received a present from Porus, an Indian chief, of about 30 lbs. weight of steel.” If this were a present fit for the conqueror of the world, its value, even at that early date, must have been great indeed.
For many centuries, up to the sixteenth, all iron was produced by the aid of wood charcoal; and with such contracted and limited means, it was found that not more than 50 per cent, of the metal contained in the ore was extracted; consequently at this day all the ancient deposits of _slag_ are sought for and re-smelted, yielding a handsome return to the manufacturer. The adoption of coal coke was a matter of necessity, but it has been productive of extensive benefit in all manufactures of iron of medium quality. The opinions of many men of science lead to the belief that it has benefited the higher quality also; but I am quite satisfied of the reverse. The quantity formerly obtained in the yield was, as shown, only 50 per cent. of the quantity existing in the ore; but yet it was the purest metal: for it is unquestionable that the best is soonest fused.
The iron ore of Great Britain is, beyond a doubt, inferior to that of many parts of the world; as all attempts to produce good steel from it have been attended ultimately with disappointment. Mr. Mushet, in his excellent work on iron, says, “The successful exertions of individuals have increased the manufacture of cast and malleable iron beyond all precedent in this country; nor have we been without some enlightened individuals, who have laudably endeavoured to form a superior quality along with the extension of their manufactures. Success has so far crowned their praiseworthy exertions, aided by the operation of knowledge, in removing the prejudices of the artisan, that bar iron of our own manufacturing has been substituted, to a great extent, in place of that formerly used of the Swedish and Russian marks; but hitherto all attempts have failed to make bars of proper quality to form steel, in any degree comparable to that we daily manufacture in great quantities from foreign iron.
“Here we remain at an immense distance behind; and while our manufacture of iron goods exceeds the collective exertions of all Europe, we humbly feel our dependence upon two foreign markets for the supply of that steel-iron, without which the beauty, the utility, and extent of our hardware manufactures would be essentially injured and abridged.
“The policy of the foreign holders of this article communicates many undue advantages to the favoured few to whom the steel-iron is consigned in this country. The rapid progressive rise in value of this iron, for many years past, has already nearly doubled the price of steel to the workman, and given the trade in general a melancholy foretaste of the evils of dependence and _monopoly_.”
So it is with the scrap, requisite to form good iron for gun-barrels. I have had several pairs of barrels sent from Berlin and Vienna, to be fitted up in the English style, with a certain knowledge that they were wanted for patterns; and in justice let it be said, the material and figure in the barrel were most beautiful: being a variety of Damascus, or fancy pattern in the metal, _superior_ to anything seen of this country’s manufacture. True, this is not an essential requisite, being more for appearance than utility; but the fact clearly shows the industry and will of the artisan. The iron, too, in clearness and density, we can scarcely surpass; therefore, if I regret that we are not advancing with our competitors, it proceeds from a clear conviction of the truth that we are slumbering upon our fancied superiority. A friend who had lately visited Liege, informed me that in one gun-maker’s shop alone, were employed fourteen of our best workmen; in fact, he brought with him a gun which attests the great improvement the Belgians have made of late years. I have had possession of three guns, bearing on the lock and barrels, “Joseph Manton, London;” “Joseph Egg, London;” and “John Manton and Son, London;” all of which were manufactured in Belgium; and so well is the imitation executed, that it would puzzle most amateurs to discover the fraud.
Recently a company, entitled “The Indian Iron and Steel Company,” has commenced importing and and manufacturing iron and steel from Hindostan ore, and native-made bar iron.[7] If they succeed in competing with Sweden and Russia, this iron will be a valuable acquisition to the British empire. They have already issued a quantity 35 per cent. cheaper then the latter, but quality is the end they should strive for. However, the business is in able hands, and I have no doubt but that this object will be kept prominently in view.
[7] The fine quality of the Indian steel is generally acknowledged. The iron is first obtained by smelting, in small quantities, the wootz-ore, or the magnetic oxide of iron, which it found combined with about 42 per cent. of quartz; the yield being, out of 100 parts of ore, only 15 parts of metal: but this is of the finest character.
The process by which the iron is converted into steel is as follows, and fully accounts for that peculiar quality for which the Indian steel is valued.
The iron is cut into pieces and packed closely in a crucible of clay, containing about 1 lb. only of the iron, mixed with a tenth part of dried wood cut small, the whole covered over with green leaves. The crucible is then stopped, by covering the mouth with tempered clay, so as to effectually exclude the air. After a time that is, as soon as the clay-plugs are sufficiently hard, from twenty to thirty of the crucibles are built up in an arched form placed in a small blast furnace, and kept covered with charcoal; thus being subjected to the heat of the furnace for two or three hours. The process is then complete.
As soon as the crucibles are cool, they are broken open and the cakes of steel are found rounded at the bottom.
The top of the cakes should be found covered with striæ, radiating from a centre, and be free from holes or rough projections. If the cakes are honeycombed, the process has been imperfect and incomplete. When re-melted and tilted into rods, a very superior article has been the result.
The natives prepare the cakes for being drawn into bars, by annealing them for several hours in a small charcoal furnace, excited by bellows; the current of air being made to play upon the cakes while turned over before it, whereby a portion of the combined carbon is dissipated and the steel probably softened: without which operation the cakes would break in drawing them. They are drawn by a hammer of only a very few pounds weight, but the repeated hammering greatly tends to the production of a highly condensed and perfect article.
Foreseeing the difficulty that would eventually beset us in obtaining a sufficient supply of old horse nails from Germany and elsewhere, I directed my experiments to steel entirely, having formerly perceived that where the greatest quantity of steel existed in the mixture necessary to form material for their best gun barrels, there also existed the greatest tenuous strength. I had at that time a decided objection to all steel, as the following quotation from “The Gun” will show:--
“We recommend hammer-hardening in all mixtures containing iron. If you throw the iron aside, and confine your manufacture wholly to steel, it would be an evil, from this simple cause:--steel is of itself close enough in the grain; hammering it, therefore, in a cold state, only tends to make it more brittle. But the reverse is the case with iron: the more it is beaten the greater becomes its tenacity; and when mixed with steel in the way the stubs-composition is, it prevents the particles of steel from becoming too hard.”
Mr. Adams, of Wednesbury, and the successors of Mr. Clive, of Birmingham, manufacture a considerable quantity both of silver steel and common twist steel for the trade; I make my own laminated steel: the difference in silver steel and common twist steel merely consists in the variety of tortuous twisting the former undergoes, while the latter is rolled out into rods of 6-16ths broad, with the fibres running perfectly longitudinal. The method of making or welding the pieces into a bloom, is in the following way. Having collected a sufficiency of mild steel scraps, such as cuttings of saws, waste from steel pen making, old coach springs, and the immense variety of pieces arising from the various manufactures of tools, they are cut into pieces of equal dimensions, polished in a revolving drum by their friction on each other, until quite bright, and then placed for fusion on the bed of an air furnace. The parts first fused are gathered on the end of a similarly fabricated rod, in a welding state, and these gather together by their adhesion, the remainder as they become sufficiently heated, until the bloom is complete. The steel is then removed from the furnace, and undergoes the effect of a three-ton forge hammer and the tilt, until it forms a large square bar; it is then re-heated, and thence conveyed to the rolling mill, where eventually it is reduced to the size of rod required. I generally have the metal required cut into short pieces of six inches long. A certain number are bundled together and welded, and then drawn down again in the rolling mill. This can be repeated any number of times--elongating the fibres and multiplying their number to an indefinite extent as may be required.
The great advantage derived in this instance from air-furnace welding is a chemical one; for while the small pieces of steel are fusing on the bed of the air furnace, the oxygen is extracting the carbon, and leaves the resulting metal mild steel, or iron of the densest description; while the succeeding hammering and rolling and re-welding, produce the mechanical arrangement of making the whole of an extremely fibrous description. The polishing secures a clean metal; indeed, so free from specks are the generality of barrels thus made, that it is scarcely possible to imagine clearer metal. When contrasted with the best of ordinary iron, by a powerful microscope, the closeness and density of grain are strongly apparent.
To such an extent has this been carried, that I can produce specimens of a considerably increased specific gravity. The barrels made of this metal, in general, beat all tried against them; with this great advantage, that the finer the polish in the interior the better they shoot, and continue longer free from lead. The only difficulty is in the working; as the boring, filing, &c., are more difficult. Moreover, greater care is required to see that they are not annealed,[8] when in the hands of the borer or filer; for in such case they would be considerably injured, though not to the same extent as barrels of a softer nature. I tested a great variety of bars by drawing them asunder longitudinally by the testing machine, and the average strength of a rod of 6-16ths broad by 5-16ths thick and 12 inches long, containing 1·40625 solid inches of iron, was equal to a tension of 11,200 lbs. This furnished a barrel having a thickness of metal in all parts of the arch equal, or 3-16ths of an inch thick, capable of bearing an internal pressure of 6,022 lbs. to the inch of the tube.
[8] Dr. Ure falls into an error in describing the process of barrel boring: he says “the barrel is first properly annealed, and allowed to cool gradually,” &c. The barrel-maker that would take such a proceeding with a barrel of ours should never do so to another. The Doctor ought to have pointed out the evil tendency of this. We never saw it done, and we doubt much whether he did, though we have heard of the practice, which induces us to notice it, but the Doctor describes it as a _necessary_ proceeding.
The generality of barrel makers spoil this metal by an attempt to obtain figure; for all extreme twistings in the rod depreciate the metal, by separating the fibres: to borrow a simile, they obtain only an over-twisted rope. This is not only disadvantageous but useless; for the extreme density of the metal renders the figure difficult to be shown distinctly, as acid acts upon it but slightly, and never so well as on metal fabricated from two differently constructed carbonised materials.
Many conjectures have been advanced, and an endless discussion created, to account for the watering or “_jowher_” in oriental sword-blades, and genuine Damascus gun-barrels. Anything approaching the truth is seldom met with; though I think the explanation is very simple. It must be well known that there is an immense variety of different qualities in both iron and steel: no uniformity of quality is found in two productions out of a hundred. The very ore, the coal, the presence of oxygen, the excess of it, all vary the quality of the material. An excess of carbon is more detrimental than a scarcity; for where carbon has once been, it leaves an indelible mark, and though extracted to as great an extent as practicable, it leaves a residue that possesses an affinity to absorb carbon again equal to the original quantity: thus, steel once made will never, by any process yet known, be reconverted back to iron of the same nature it was originally.
Mr. Mushet has given us the proportions of carbon _held in solution_ by the various qualities of steel and iron, and the reader will find them in the note below.[9] It inevitably follows, as a principle, that the quantity of carbon contained in the metal--avoiding cast iron--will increase or decrease, and thus regulate the degree of hardness of the metals in question. A quantity of metals dissimilar in this particular, mixed together, and run into a vessel in a state of fusion, then, when cold, filed and polished, will show a variety according to the place they hold in the crystallised mass. Work and twist this material in all the tortuous ways and shapes it is capable of, and you only twist the fibres of the different bodies in the same way; and when they come to be acted upon by acid or oxidisation, they still retain their relative positions, forming the watering or figure, as was the intention of the tortuous twisting. All the beautiful arrangements in Damascus figures are obtained in this way. Metals containing more or less carbon will always produce this watering. To obtain a satisfactory proof, any person may case-harden a few pounds weight of stubs, and afterwards melt them in a crucible, and run them into a receiver; when these are worked down into the bar (or not, as he pleases), dress and apply a little sulphuric acid, and the peculiar situation the various stubs had taken in the fluid state, will be clearly discernible.
[9] Iron, semi-steelified, is made with charcoal 1-150th part. Soft cast steel, capable of welding with ditto 1-120th do. Cast steel, for common purposes, with ditto 1-120th do. Cast steel, requiring more hardness, with charcoal 1-90th do. Steel, capable of standing a few blows, but quite unfit for drawing with ditto 1-150th do. First approach to a steely granulated fracture is from 1-50th to 1-40th do. White cast iron, with charcoal 1-25th do. Mottled cast iron, with ditto 1-20th do. Carbonated cast iron 1-15th do. And supercarbonated crude iron 1-12th do.
The original barrel-welders, the real Damascus iron-workers, were, like some of ours of the present day, not the most _conscientious_ individuals, nor the most honourable. For, strange to say--but it is not more strange than true--on examination of most real Damascus barrels to be met with, we find the iron must have been so valuable as to induce the workmen _to plate_ or _veneer_ the superior mixture over a body of the commonest iron: all large barrels are thus made, rifles especially. I presume the moderns _borrowed_ the invention; and it would be well if they made no more extensive use of it than on rifle barrels.
The modern method of making wire-twist and Damascus iron, being gradations from the same material, are here described under one head:--
Alternate bars of iron and steel are placed on each other, in numbers of six each; they are then forged into one body or bar; after which, if for the making of wire-twist barrels, they are rolled down into rods of 3-8ths of an inch in breadth, varying in thickness according to the size of the barrel for which they are wanted: if for Damascus, invariably 3-8ths of an inch square. When about to be twisted into spirals for barrels, care must be taken that the edges of the steel and iron shall be outermost; so that when the barrel is finished and browned it shall have the appearance of being welded of pieces the size of wires, the whole length of the barrel. A portion of the rod, pickled in sulphuric acid, exhibits the following appearance, the bright parts being the steel, the other the iron.
When about to be converted into Damascus, the rod is heated the whole length, and the two square ends put into the heads (one of which is a fixture) of a kind of lathe, which is worked by a handle similar to a winch. It is then twisted like a rope (or, as Colonel Hawker says, wrung as wet clothes are) until it has from twelve to fourteen complete turns in the inch, when it presents this appearance.
By this severe twisting, the rod of six feet is shortened to three, doubled in thickness, and made perfectly round. Three of these rods are then placed together, with the inclinations of the twists running in opposite directions; they are then welded into one, and rolled down into a rod 11-16ths of an inch in breadth. Being pickled in acid, to eat away the iron, it exhibits the following appearance:--
This iron has long been held in great esteem. It looks pretty; but certainly does not possess either the strength or tenacity of wire-twist iron. It is well known that the strength of a rope may be destroyed by twisting it too much: so is it with this sort of iron. Iron is best when not twisted at all: I speak of the bar. It resembles wood, inasmuch as the strands or fibres run parallel, firmly adhere, and add strength to each other; if you twist those fibres you tear them asunder, and they no longer support each other. So it is with iron.
The objection made to the wire-twist is, that owing to the iron and steel being perfectly separate bodies running through the whole thickness of the barrel, there is a difficulty in welding them perfectly; and, of course there is danger of their breaking across, at any trifling imperfection or mis-weld. This objection is certainly well grounded, as many barrels break in the proving. I have seen a very strong barrel indeed broken across the knee without the slightest difficulty, while, to all appearance, it was perfectly sound. This is the reason why the manufacturers have ceased to make them, except for the American trade.
It may be said that the fibres in the Damascus, after being torn asunder, are welded anew. True; but could you ever glue the fibres of a piece of wood (twisted in the same way) together again, to make them as strong as before? No: cut several pieces of wood across the grain and glue them together, you would not expect them, though equal in substance with a piece in which the grains run lengthwise, to be of equal strength. In short, I hold a Damascus barrel to be little superior to a common barrel, in which the fibres run parallel to the bore.
All the varieties of figured barrels are but modifications of Damascus. The most endless variety possible may be attained; a figure with the carbonised material, showing only the ends or edges of the various laminæ, or portions of the face of that laminæ, may with equal facility be obtained, if the patience of the artist be in proportion. It would be a never-ending task, a subject for many volumes, to endeavour to describe a tithe of the varieties that might be, and have been made.
The Belgians are very expert at this sort of ornamental work. The very minute Damascus figure they frequently produce, is admirable, if beauty alone were the advantage sought in a gun barrel. They use thirty-two alternate bars of steel and iron, and roll them into a sheet of 3-16ths thick, and then slit them by a machine into square rods; these are twisted in the way just described, but to such an extreme as to resemble the threads of a very fine screw: six of them are welded into one, instead of three as with us. The figure is so extremely fine as to appear not to be larger than the finest needle. I have seen barrels made in Liege, superior in minute figure to any real Damascus barrel, or sword either. Our workmen here say the steel is better; which I am inclined to think is true: it is a branch of the gun manufacture they have long excelled in. The very best “Damascene” workers are to be found at La Chafontaine, a few miles from Liege, where they dwell in as beautiful a dell as fancy could wish, with a powerful hill-stream working their boring and grinding-mills, thus enabling them to send their barrels into Liege, ready for the filer. I have spent considerable time, and taken great trouble, to produce in Birmingham iron equally good; and I have succeeded: but, unfortunately, Englishmen are so extravagant in their ideas of value, as to render the constant manufacture of this iron here, a losing speculation. It can, however, be obtained from Belgium now, under the amended tariff, at ten per cent. on the value. It can be purchased there, ready for barrel making, at a franc per pound; and cheap it is at that price: two and a half francs would not purchase it here.
That Damascus iron is incompatible with goodness, I can and shall clearly prove. Experiment with the testing machine shows a rod of wire-twist 3-8ths square, containing 1·6875 solid inches, as equal to a tension of 11,200 lbs.; whereas a rod, when converted into Damascus of 11-16ths of an inch in breadth, by 4-16ths in thickness, containing 2·625 solid inches, was only equal to 8,960 lbs.; thus showing a clear loss of full thirty-five per cent. And when welded into barrels of the dimensions described, the relative internal strength of each is 5,019-1/2 lbs., and 3,292 lbs. _to the inch of tube_. This constitutes a great difference. But unfortunately that is not all.
In the preceding chapter I noted the fact, that all sorts of iron lose a portion of their strength by being heated or softened; but I found that Damascus suffered more than any other sort of iron, excepting the common kinds. For instance, the bar of wire-twist would, in the state it came from the rolling mill, bear 11,200 lbs., but, after softening, it would only bear 10,180 lbs., being a diminution of 10 per cent. A bar of Damascus suspending a weight of 8,940 lbs., the measure of its strength, when annealed, was 7,840 lbs., being a falling off of 12-1/2 per cent. Thus, I trust I have clearly shown, that whatever other quality Damascus possesses, strength is not one of its properties. It must not, however, be supposed that the above weight indicates its greatest strength; on the contrary, its strength can be increased full 22-1/2 per cent. by cold hammering. Still, however, it will only hold its relative position to other kinds of iron with respect to strength, since they are all capable of having their strength increased by the same process.
Damascus barrels have fallen much into disuse, being rarely seen except as pistol barrels,[10] which, together with a great quantity of _counterfeits_, are made for the South and North American trades, in the shape of double and single guns of a flashy appearance--all invariably _veneered_ or _plated_ with ribbons of this ornamental iron. I shall now dismiss this subject; after remarking, that certainly a very handsome barrel may be made after this principle, if too much twisting be avoided. It has been seen that the rods are twisted until there is fourteen turns in the inch of length: an excess productive of the detrimental effect mentioned; while, had there been but two turns, a large proportion of strength, if not all, would have been retained. One turn only, under the same circumstances, would very likely be highly beneficial; indeed I have found it to be so: one twist binds the interior strands, as the outer does the interior in a rope, and thus adds strength. This shows that there is a medium in all things.
[10] The London makers are again using them extensively; which is certainly no proof of their judgment.
The use of old horse-shoe nails is of a date nearly coeval with the use of small fire-arms. These nails are made from rod iron of the best description; and the hammering cold, or tempering the nail, so benefits and condenses the iron as to improve it greatly. The method in use until a late period, was to fill and force into an iron hoop, of six or seven inches diameter, as many stubs as it would contain, to weld the whole, and draw them down to a bar of such dimensions as might be required. Modern improvement, however, has shown the advantage of cleansing the stubs perfectly by a revolving drum, and then fusing and gathering them into a _bloom_ on the bed of an air-furnace. Thus a body of from 40 to 50 lbs. of melting iron can be obtained at one heat; a matter of economy and necessity, where large quantities are required, besides possessing the superior advantage of having the whole mass equally heated: this cannot be done by the old hoop method, as the surface must be frequently burnt before the interior is at all in a welding state.
Experience taught the late Mr. Adams and his brother George--who still manufacture some of the best gun iron in the world--that the stub iron alone was insufficient; for even then (forty years ago) the absurdity of imagining that no barrels were or could be good without being soft, was understood and acted upon by them. They introduced at first one-fourth of steel to three of stubs; this having been found highly advantageous, the prejudices of the gun-makers were gradually overcome, or left in abeyance from ignorance of the introduction. It is a fact, that as late as 1842, when I issued my former work, men who had been all their lives _gun-makers_ (by courtesy) actually refused to believe that any steel at all entered into the composition of the best barrels; and several whom I know perfectly well, ordered the factors with whom they dealt “to be sure to send them no barrels with steel in, as they did not wish their customers’ hands to be blown off.”
Charcoal iron has, up to this day, been the only stub twist barrels they (and we believe two-thirds of the provincial makers also) have ever been served with. Reason with these men, and they will snappishly tell you, “We pay the best price, and we ought to have the best: we don’t see that our neighbours have any better.” On one occasion of my calling upon one of the first provincial gun-makers in the kingdom, the subject of barrels was adverted to--“An excellent work that of yours, I dare say; but, sir, you have done a deal of harm: it is wrong to let gentlemen know too much; they give you far too much trouble: they get too knowing.” These, and such like observations, are the only thanks I ever received from the generality of the gun trade. There are, however, some enlightened men who, understanding the subject, have appreciated my motives; but by far the greater proportion have done the reverse, asserting “that I had told them nothing but what they knew before.”
The mixture of a portion of steel with the stubs having clearly shown an improvement, an increased proportion has been adopted by various makers: we have had as high as three-fourths of steel to one of iron. Where proper attention is paid to the clipping of the steel to pieces, corresponding with the stubs, and properly mixing the whole, welding and forging by the heavy hammer, reducing by a tilt and rolling down to the smallest description of rod, a most excellent, tenacious, and dense body of iron is thus obtained; while, by cutting into lengths of six inches, bundling a number together, and re-welding them into a bar, an increased density and tenacity is gained, by an increase in quantity, and an elongation of the fibrous system. Any description of barrel, of this iron, if made with a moderate degree of care and attention, is considerably stronger than any explosive fluid ever yet compounded could burst, under any circumstances bordering on _fair experiment_.
The great advantage derived from welding on the bed of an air-furnace, arises from an absence of the minute portions of charcoal, of either wood or coal, as the case may be. Millions of these very minute portions are imbedded in the midst of the metal in every part. They are enclosed in cells originally of their own dimensions, but are drawn out with the fibres to an indefinite extent, forming a system of tubes that may be compared to the capillary system in trees, and making the iron of a spungy, compressible nature. It is the absence of these particles of charcoal that gives part of the superiority to steel as now made for gun-barrels; and the existence of a portion of them causes the inferiority of all other kinds of iron. In a chemical analysis of iron, a large portion of crude coal-charcoal or wood-charcoal is found, according as either has been used during the manufacture. This is not of course given as so much carbon in the result, though the injury is equally detrimental as an excess of carbon is to the goodness of the metal; for it renders the whole porous, and liable to attract moisture and induce oxidation. It must be kept prominently in view, and clearly comprehended, that the denser the body of metal, the less the liability to oxidise, or in other words _rust_; and here is the one great preservative principle in good iron: “it is the fibre of dense cocoa-wood, compared with that of willow or saugh.” In all situations and for all purposes, where iron is liable to sudden changes of either heat or cold, wet or dry, the very best of iron should be obtained; as it will be less affected by the changes of temperature, and amply repay by its durability the extra cost in the first instance.
The very extensive round of experiments to which I have submitted mixtures of this nature, clearly establishes all the conclusions I have formed on these points. The strength of the mixture, three parts steel to one of stubs, gives a resistance in the rod of 6-16ths broad by 5-16ths thick, and 12 inches long, containing 1·40625 solid inches, equal to 10,295 lbs. before separating; thus being equal, in a barrel of the dimensions before mentioned, to an internal pressure of 5,555 lbs. to the inch of tube. The proportions mentioned in my previous work are 25 lbs. of stubs to 15 lbs. of steel; the strength of this mixture in the rod is equal to a tension of 8,960 lbs., and the barrel is capable of restraining a pressure internally of 4,818 lbs., making full 15 per cent. dissimilarity in favour of the larger proportion of steel: indeed, all experience points to the great advantage, that steel, properly worked, possesses over iron alone. Great good can be effected by condensing iron by hammer-hardening; greater than I have shown steel to be capable of receiving additionally: as, already having it naturally, there is no necessity for using artificial means to obtain it. Nor is steel so liable to depreciation in the hands of an inexperienced artisan; as the degree of expansion is not more, in the large proportion of steel mixture, than a loss of strength equal to 4-1/2 per cent, by heating and cooling gradually. The loss in the mixture containing less steel is 7-1/2 per cent. The specific gravity of the two is in proportion.
The frequent welding and re-rolling of iron is of the most beneficial tendency, the elongation of the fibres being highly advantageous; for, a fibrous piece of iron may be compared to a wire rope, the more strands the greater tenacity; and the smaller the strands, even up to a proximity of fineness to the human hair, the greater the weight they will bear in tension. One large wire which, when single, will suspend 500 lbs., will, when drawn down to six small ones, suspend 600 lbs.; and so on to the greatest extreme. Another great advantage received by the repeated reworking of iron, is obtaining an increased density; for when this is secured to a certain extent, you have closed in proportion the pores of the metal; and in this state it is not liable to that degree of expansion or contraction, or that fluctuation in strength, which arises from softening the iron. Nor can you gain, save to a limited extent, any improvement by hammering,--hammer-hardening, for instance,--simply because it is already improved to the utmost extent we are at present acquainted with.
How wonderfully beneficial to mankind is this beautiful arrangement of the metallic fibrous system! Without it what could we do? our manufactures would be confined to simple castings, or crystallizations, possessed merely of strength in proportion to the cohesive nature of the metal. Where would be all the wonderful springs whose fineness vies with the silken fibre? Of what could they be constructed? All-powerful gold would not suffice, nor silver; though each, in its place, possesses wonderful properties. Gold and silver may both be spread in the thinnest conceivable coat over space incredible; on the gilded cup, or, still thinner by electric agency, on the plated epergne. But iron alone is to the arts, the “_summum bonum_” for which there is no substitute: it is the “_sine quâ non_” of practical mechanics.
Improvements in the manufacture of a very superior iron may, we believe, be placed to the credit of the gunmaking profession exclusively; no other body or class of men having ever yet deemed it worth their trouble to endeavour to obtain anything of a better description _than bar iron, suitable to make steel from_. Mr. Mushet, from whose work I have already quoted, has evidently been more intimately acquainted with the routine of iron manufacturing than any other person I ever met with or read of: he understands the question perfectly; yet he seems to care for nothing further _than a suitable steel iron_.
How many and how fearful have been the explosions by all-powerful steam since the period of its introduction. How many weeping widows, and how many fatherless children have had to mourn its effects! Yet what has human ingenuity done, what have the wonderful energies of the present race of scientific men accomplished to stay this annual slaughter? Comparatively little beyond discovery of mysterious causes where none exist. It reminds me of my first lesson in coursing--“If you want to find a hare, young man,” said the keeper, “look at your feet: you will not find her at a distance.” So it is with the state of knowledge on steam boiler explosions; if you want to find the cause, look “at your feet:” do not endeavour to envelope in mystery, what you may find in simple and natural causes.
I may here observe that I have been professionally engaged to inspect the effects, with a hope of finding the cause, of thirty-four cases of explosion, where the sacrifice of human life was above an average of two each, or nearly one hundred, and I never yet have found one single case which could not be clearly demonstrated to have been caused either solely by neglect of the superintendent, or from sheer ignorance on the part of the engineer constructing the arrangement of boilers. For every accident may _sweepingly be said_ to be occasioned by a want of space for the escape of the steam: a too small valve, in the first instance, and in the second, a villanous construction of what is called iron boiler plate--a concentration of the veriest rubbish, under the name of wrought iron, ever gathered together. For this reason, I have drawn the reader’s attention aside for a few moments.
The improvement of boiler-iron may detain us slightly, if by the delay any good can be accomplished. For an inconsiderable increase of outlay, a boiler might be rendered doubly safe to what it is at present, by simply using moderate caution in the selection of scrap iron, a perfect cleansing of that scrap, and by fusing the bloom on the bed of an air furnace. The great advantage would be that you would get a stronger, a much denser, and consequently a much better, metal: nor is this all the advantage; you might use a very much thinner plate, which would yet be equally strong; and science will tell you that steam would be more easily generated, as heat is more rapidly conducted.
There is a very handsome description of barrel-iron made, generally termed “Stub-Damascus.” The method of preparing it, is of late considerably altered. A quantity of old files are hardened, by being; heated red-hot and immersed in water, then broken in pieces with a hammer, and afterwards pounded in a mortar until the pieces do not exceed in size a corn of number five shot. A proportion of 15 lbs. of these to 25 lbs. of stubs, is fused together on the bed of an air-furnace, beaten down, and rolled into rods. The rod of 3-8ths of an inch square, is twisted like a rope, precisely in the same way as the Damascus. The effect of this winding, is to give a beautiful mottle to the barrel; which will be found depicted in plate No. 3.
Another mixture, represented in plate No. 2, was first made by Mr. Wiswould, of Birmingham. It is a compound, so far as I have been able to ascertain, of three parts of steel to two of iron, intimately blended and intermixed, and twisted as just described. It is a most beautifully clean and dense iron; but the extreme twisting is to it, as to all, highly injurious and prejudicial. The twisting is similar to the Damascus; only that two twisted rods are welded together instead of three, and with the twist of the strands running in opposite angles, as depicted in the wood-cut below.
The degree of strength is similar to that of the stub, and other Damascus; it being quite certain, that, be the composition what it may, this rending of the cohesive attachment by twisting, will eventually equalise the strength of the whole.
The use and introduction of what is called “charcoal-iron,” is one of the shams reared and supported by the hotbed of competition and deception combined: a wish to foist on the purchaser a counterfeit for the real metal. I would not give shop-room to the best barrels ever made from such a compound. I hate a scoundrel and a hypocrite; this iron exemplifies the qualities of both.
This worthless compound consists principally of cuttings of sheet iron; of which there is an endless supply in the neighbourhood of Birmingham, from punchings and from one inferior metal and another. After properly cleaning, a quantity is put into a charcoal furnace and melted, cast into a pig, then forged down to a bar, and rolled into rods corresponding with the size of stub twist, which it is intended to represent. The action of the charcoal communicates to it a portion of carbon, which, when stained in a certain way, gives an appearance much resembling that beautiful metal just mentioned (stub-Damascus); but if every means imagined by the inventive faculty of man were employed upon it, it could not be made into really good iron. An iron which is technically termed “weak,” can never be made a strong bodied iron, or an “iron suitable to make steel,” to repeat a former quotation. The original iron from which these scraps generally come, is required to be “weak” iron, for the facility with which it can be rolled into plates; a strong fibrous iron is not necessary.
Its greatest strength appears to be as follows: 7-16ths of an inch broad, and 5-16ths thick, solid contents 1·40635 inches, will bear a weight of 10,080 pounds; so that if my calculations are correct, it will bear only a pressure of 4,526 pounds in the tube. The loss of strength by heating or softening, being full 10 per cent.
This converted iron, however, will not endure the test of browning by smoke, or, more properly, flame; as the oxygen invariably destroys the appearance of steel in twelve hours after its application. By the old method of staining, it would be as impossible for any man, who was not a judge, to point out the real from the counterfeit, as to discern a copy executed by a clever artist from an original painting by one of the old masters.
But deception is ever fertile in expedients, and an ingenious invention was soon found out to imitate the advantage possessed by the “_smoke brown_,” which they obtain by first browning or staining the barrels very dark. A weak solution of muriatic acid, or spirits of salt, is applied very lightly with a sponge, and the colour is extracted from those portions of the iron left more prominent, by the excessive _pickling_ they are subjected to before staining; they are then immediately dried, scalded with hot water, and the stain is complete; it is a most ingenious imitation.
I have already stated that this iron is very much used in consequence of its cheapness; its cost being only fourpence per pound, while stub twist costs fivepence. It is also easily worked, being considerably softer than any of the above-described kinds of iron.
It may be asked, why so much inferior iron is used, when the difference in the price between the good and the bad is only a penny per pound? The reason is this:--If a barrel filer receive an order for a pair of barrels, he (having probably deceived his customer before, or, at any rate, knowing that he can deceive him without running any risk of detection) sends to the welder sufficient charcoal-iron to forge these barrels. Should the quantity amount to ten pounds, he, of course, saves tenpence. The welder receives two shillings less for welding this description of iron, than for welding stub-twist; so that here is already a saving of 2_s._ 10_d._ At the boring-mill, and the grinding-mill, the charge is also proportionate: the wages of the journeymen are less; so that by imposing on his customer one pair of barrels manufactured of this sort of iron instead of the real stub-twist, he pockets a clear gain of above 9_s._; and should he manufacture one hundred pair of such barrels in the year, it would make at the end no small item in the year’s account of profit.
Thus it is with all description of barrels. The charge for making, by each workman, in the various stages of the manufacture, is according to the quality of each pair of barrels. The saving, then, to the man who makes one hundred pairs of barrels in the year, though it be but a farthing in the pound of iron, amounts to a considerable sum. This fraudulent gain of more than 5_s._ on a pair of pretended stub barrels, is what is called in Birmingham, “doing the natives,” and is a reward for ingenious knavery.
When orders are given by what are called general factors, who very kindly supply their country friends at a moderate commission of 40 to 50 per cent., these gentry take care to lap up the cream; for we know from facts that the barrel filer has sometimes scarcely five per cent. for his trouble of overlooking. One consequence naturally results from this, that every species of deception will be resorted to, in order to indemnify workpeople for their labour and trouble. At the present time, I have no doubt that there are hundreds of guns made in Birmingham, the barrels of which, in some instances, never enter the proof house: as eightpence per barrel, the cost of proof, is a great temptation! Besides, a great number of barrels declared “wasters”--such as repeatedly bulged in the proof, are full of flaws, have holes in the sides, or some other fault sufficient to condemn them in the eyes of a moderately conscientious barrel-maker--are bought by men who live by this species of fraud; and are repaired with great neatness, by putting in pieces artfully, beating down swellings or bulges. Then the proof-mark “of doubtful identity;” and, last of all,--mark!--they fit them up, and send them to the engraver to have the name of some living or defunct London gun-maker of respectability engraved upon them, and palm them off upon some dealer as a good article.
I commend to the reader the advice of “Edward Davies,” a gentleman who wrote in 1619; who says “He that loves the safetie of his own person, and delighteth in the goodness and beautie of a piece, let him always make choice of one that is double breeched; and if possible, a Mylan piece, for they be of tough and perfect temper, light, square, and bigge of breech, and very strong where the powder doth lie, and where the violent force of the fire doth consist, and notwithstanding thinne at the end. Our English pieces approach very neare unto them in beautie and goodness, (their heaviness only excepted) so that they be made of purpose, and not one of these common sale pieces, with round barrels, whereunto a beaten souldier will have great respect, and choose rather to pay double money for a good piece, than to spare his purse and endanger himself.” Truly, the fraternity have always, we find, been of doubtful honesty: always making “sale pieces.”
“Threepenny skelp iron” is made from an inferior quality of scrap to that from which “charcoal iron” is made; but unlike it, there is no pretension of quality. Its inferiority is not denied; it is poor in quality, and suits parties who cannot buy better. The method of preparing is by an air-furnace, forge, tilt and rolling mill, as before described. The greatest strength of a bar 11-16ths broad by 3-16ths thick, containing 1·5468 solid inches, is 7,840 lbs.; or equal to an internal pressure of 3,841 lbs. to the inch of tube. One particular fact attaches to all kinds of inferior iron--the greater the mass acted upon by the rollers the greater the variation of strength. This arises entirely from the increased sponginess of the metal, and its greater expansibility. For instance, a rod 1-16th thicker, is 15 per cent. weaker in proportion; and so on to the greatest extent. But on the other hand, it is capable of recovering a great increase of strength by cold hammering; greater than better iron. A considerable quantity of this iron is sold to engineers, and used in the construction of locomotive and other engines; the price and uniformity of texture in grain fitting it for that purpose.
“Twopenny” or “Wednesbury skelp” is almost too bad to be used in making an article which may endanger the limbs of our fellow creatures, and is now little used, fortunately. It is made of an inferior scrap to the former, in precisely the same manner; and in point of strength is still lower. The bar is generally 1 and 1-16th inches in breadth, by 3-16ths thick, the solid contents 2 inches and 25-64ths, and will bear a weight of 7,840 pounds; consequently the strength will be 2,840 pounds to the inch of tube.
This is a great falling-off in strength; and I would ask any one who values the safety of his hand, if he would like to risk it, by using a gun made of iron possessing so low a degree of strength, as compared to the force of the charge it has to bear? Let him recollect that the force of the charge may be increased by a variety of circumstances. The pressure of a certain quantity of powder, on which a certain weight of shot is placed, is so many pounds to the inch; and if you double that weight of shot, you nearly double the pressure. In estimating the force of pressure, the opposing friction is also to be taken into account. If the gun be allowed to get very foul, then friction is increased, and of course a still greater pressure is thrown on the tube of the barrel. All these circumstances being taken into consideration, I repeat, that _no barrel is safe, whose power of resistance is not more than double the strength of a charge of sufficient force for general shooting_. Every bad gun should be thrown aside as unsafe, or used with the greatest caution. Bad and inferior guns are made from the foregoing material; and not many years have elapsed since it was thought good enough for military arms.
“Sham damn skelp” is made from the most inferior scrap. I should not have mentioned this description of iron had I not seen hundreds of barrels made of it, all which are utterly unfitted for the use of any person who cares at all for his safety. I have met with them frequently under the dignified name of twisted barrels. Guns that are fitted up at from ten to twelve shillings each are not of course patent breeched, but are made to appear so by staining them generally blue, and by having a couple of bands to imitate platina, across the squares. A projecting part is welded on to the side, into which the nipple is inserted, and the lock joints neatly under it. Many of them are good imitations; but only take the barrel out of the stock and the deception is instantly apparent, as it is rarely carried further than the outside. The beautiful way in which the barrels are painted to imitate fine twist, catches the eye of the simple countryman, who is generally the dupe of this artifice; and the persuasive eloquence of the itinerant hardwareman, seldom fails to extract from the pocket of his unsuspecting purchaser sometimes thirty or forty shillings of his earnings for what the _modest trader_ rarely pays above fifteen shillings. Many are the anathemas vented, when the deception is found out by some one more knowing than the dupe, who not unfrequently purchases his experience at the expense of a finger or a hand. It is astonishing what a quantity of this rubbish is disposed of by hawkers who infest market towns and villages with guns for sale.
But the English peasant is not the only dupe of this species of knavery. Thousands of these guns are sent monthly to the United States, to the Brazils, and South America; where they are disposed of, among the poor Indians, in exchange for skins and furs.
They are all understood to be “proved.” How many are so who can tell; but that some of them are not, there can be no doubt.
It is said that the manufacture of these guns is a great support to the gun trade of Birmingham. In one respect it is, certainly; yet would not the interest of the trade be advanced, if we were to manufacture none of so inferior a quality? “But then,” it will be urged, “we could not compete with our rivals in Germany and the Netherlands.” True, we should not be their rivals in the production of rubbish; but the superiority of our guns would then command a better market. By sending to the market an article no better than theirs, we have made foreigners indifferent about the purchase of ours: they say “The English guns are no better than the Belgian or German; we may as well purchase one as the other.” The force of this remark is illustrated by the state of the African trade. The base kind of articles we supplied them with some years ago, has produced a distrust of our manufacture, which will not easily be removed; and a similar distrust is engendered by the same cause in the minds of our present customers. It is much to be deplored that the eagerness for present gain, should render men blind to the consequences of their conduct, and lead them to prefer the immediate gratification of their avarice even to their own future prosperity; to say nothing of the welfare of the trade of the country.
The method I suggested of testing all iron in the bar would go far to destroy this trade. I have not thought it worth while to test this iron. But twist barrels are made of it. Should the reader meet with a double gun so made, let him avoid it: it is unsafe, unless it be so heavy as to be unmanageable.
A great many long rifle barrels are made of this iron, principally for the American trade; but from their immense weight, and the small charge of powder required, there does not exist the same danger from their use.
Fowling-piece barrels made of it may be generally recognised by the smallness of the bore and the thickness of metal. As the charge of powder used in proving is very small when compared with the charges for proving guns of a wider calibre, we need not be surprised that many of those that are proved stand proof.
“Swaff iron forging” is a profitable branch of forging carried on in Birmingham under the above title. It is a metal which is composed of iron and steel filings, chippings of breeches, pieces and cuttings of the ends of the screws, lock-plates, cocks, the rough borings of barrels, and all other small scraps found in gunmakers’ and other workshops. These are collected by the boys in each shop, and when they have accumulated, are sold to the “swaff-forger,” the proceeds being considered as drinking money. They are forged into bars of iron by attaching them together and immersing them in diluted sulphuric acid; then, after draining it from them again, and placing a large iron pan full in a hot situation, they become cemented together by the action of the oxide. The compound is then taken from the pan, by turning it upside down, and is put into an air-furnace heated to a welding heat, being thence removed and beaten into a bar: three men with light hammers beating it as quickly as they do in welding a gun-barrel. This iron is sold to the gun-work forgers, for the forging of the patent breeches, lock-plates, furniture, and other parts of the gun which they think worthy of good iron; but since cheapness has become so much the order of the day, the use of this iron is confined to the forging of best gun-work, cast iron being thought quite good enough for common gun-work.