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.
[Illustration]
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.
[Illustration]
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.
[Illustration]
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:--
[Illustration]
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.
[Illustration]
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.