A CERTAIN IMPROVEMENT IN THE ART OF MAKING OR MANUFACTURING BAR IRON OR MALLEABLE IRON
Year: 1835

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
MUSHET, of Coleford, in the Parish of Newland, in the County of Gloucester,
Ironmaster, send greeting.
WHEREAS His most Excellent Majesty King William the Fourth, by
His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Twenty-second day of October, in the sixth year of
His reign, did, for Himself, His heirs and successors, give and grant
unto me,
the said David Mushet, His especial licence, full power, sole
privilege and authority, that I, the said David Mushet, my exors, adñiors,
and assigns, or such others as I, the said David Mushet, my exors, admors,
or assigns, should at any time agree with, and no others, from time to
time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend my Invention of "A
CERTAIN IMPROVEMENT IN THE ART OF MAKING OR MANUFACTURING BAR IRON
OR MALLEABLE IRON," within England, Wales, and the Town of Berwick-upon-
Tweed; in which said Letters Patent there is contained a proviso obliging
me, the said David Mushet, by an instrument in writing under my hand and
seal, particularly to describe and ascertain the nature of my said Invention,.
and in what manner the same is to be performed, and to cause the same to bo
enrolled in His Majesty's High Court of Chancery within six calendar months:
next and immediately after the date of the said recited Letters Patent, as in-
and by the same (reference being thereunto had) will more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
David Mushet, do hereby declare that the nature of my said Invention, and the
manner in which the same is to be performed, is described and ascertained as
follows (that is to say):-
My improvements in the art of making or manufacturing bar iron or
malleable iron relates to that part of the said art which is commonly termed
the puddling process, being the process now most generally practised for
converting crude or cast iron into malleable iron by action of heat and flame
in a particular kind of air furnace called a puddling furnace. A Patent was
granted to Mr. Henry Cort, in the year One thousand seven hundred and
eighty-four, for what is now termed the puddling process as aforesaid. And
for clear comprehension of the meaning which I attach to several technical
terms which must be used in this Specification, I wish to be understood that
the term cast iron is used to designate all the various qualities of crude
iron which are obtained from the smelting of ores of iron, otherwise called
mine, by the operation of what is called the blast furnace, which operation
produces fusible metal, capable of being melted again, and which is commonly
called cast iron, because it can be cast by pouring it when in a fluid state
into moulds; it is also called pig iron or sow metal, from the shape of the
crude ingots into which it is cast when it is run out of the blast furnace.
Such crude or cast iron is generally admitted to be iron combined with
carbon, and it is supposed to derive fusibility from the carbon which it contains,
and the various degrees of fusibility of cast iron of different qualities are
supposed to be very greatly influenced by different proportions of carbon being
combined with the iron. The different qualities of cast iron are designated
in trade by numbers, No. 1, No. 2, No. 3, and sometimes No. 4, the highest
number being considered the best quality and the most valuable, being tho
most fusible and supposed to be richest in carbon. Nos. 1 and 2 (otherwiso
called dark grey iron, from the color which it presents when newly broken)
and No. 3 (which is called grey iron), are all used by iron founders for making
castings, and hence are all called foundry metal. The crude or cast iron, or
pig iron, which is made by the blast furnaces, expressly for the purpose of
being afterwards converted into malleable iron, is commonly called forged pig
iron or bright grey iron. It is considered inferior in quality to either the
No. 1, 2, or 3, used by iron founders, being less fusible than they require
it to be, and it is supposed to contain less carbon. Also a still less fusible
quality of cast iron than the bright grey, and supposed to contain less carbon,
is occasionally made by blast furnaces for conversion into malleable iron. It is
called mottled cast iron from the colour of the fracture. And lastly, a very

page_text: inferior quality, called, from the colour of its fracture, white cast iron, is
sometimes produced by the blast furnace. It is more difficult of fusion and is
supposed to contain less, carbon than the other qualities, and requires to be
mixed with cast iron of richer qualities. Before such cast or crude iron
called forge, pig, or bright grey iron, or else mottled iron, as aforesaid, is sub-
mitted to the puddling process before mentioned, for the purpose of being
converted into malleable iron; the crude iron is usually prepared for that
process by a previous operation of melting in a furnace, called a running-out
fire or furnace, otherwise called a finery, coke being used for fuel, and the
fire being blown by blast, which is directed downwards upon the melted metal.
After being so melted and run out or refined, the prepared cast iron is called
refined metal, and in Staffordshire it is called plate. By the operation of the
running-out fire or finery, the iron is supposed to be deprived of a portion of
the carbon which is contained in the state in which it was first obtained from
the blast furnace, which deprivation is supposed to be owing to the dissipation
or burning away of that said portion of the carbon in the running-out fire or
refinery, and the refined metal or plate becomes less fusible than it was before,
which is a desirable preparation for undergoing the puddling process.
Note, the aforesaid refining of crude or cast or pig iron, by the running-
out fire or finery, as a preparation for its conversion into malleable iron by
the puddling process, was introduced after Mr. Cort's Patent, and is not
stated in his Specification, but it has been the general practice for many years.
The aforesaid different qualities of crude, or cast, or pig iron, which are
obtained from the blast furnace, such as grey, mottled, or white, are mixed
together when put into the running-out fire or finery, in order to obtain a
medium quality of refined metal or plate, and approximate as near as can be
done towards uniformity in quality of the refined metal or plate which is to
be treated in the puddling furnace, so as that operation may be conducted with
regularity. The operation of the running-out fire or finery is so conducted
as to act more or less intensely upon the crude iron which is subjected to it,
according as previous experience has pointed out to be the most suitable, by
way of preparing each quality of crude iron, or each mixture of different
qualities thereof, for conversion into malleable iron in the puddling furnace.
The iron under these circumstances is supposed to be deprived of carbon, until
only such a portion remains combined with it as will render it most suscep-
tible of 'conversion. When tho running-out' fire or finery is managed
so as to operate in its least degree upon the crude iron (and as is
supposed has had the least effect in depriving it of carbon), the refined
metal or plate which results is said to be underblown; or it is said

page_text: to be full blown when the running-out or finery operation has been
carried further, and (as it is supposed) the metal has been deprived of still
more of its carbon. Crude or cast iron so prepared, and called as aforesaid
refined metal or plate, is said to be either underblown, or fully blown, or to be
refined in any such intermediate degree between those extremes as is found
by daily experience to be most suitable to the quality or mixture of qualities
of the crude iron for rendering it susceptible of being converted into malleable
iron by the puddling process. The puddling furnace is of the kind called" an
nir furnace, and a suitable quantity or charge of the refined metal or plate is
heated therein by a strong fire of pit coal, the flame thereof being urged by
the draft caused by a high chimney to infringe upou the charge of metal,
which, becoming partially melted or brought into a semi-fluid state, is then
continually stirred up and turned over, in order that the current of flame may
act equally upon all parts of the semi-fluid mass, which, after some continuance
of the action of the flame, commences a sort of ebulition or effervescence, from
the effect of intestine motion called fermentation, during which the semi-fluid
metal appears to glow with increased heat, and a blue flame is emitted. The
stirring, and turning over is continued vigorously during the fermentation, in
order that the whole mass may be subjected to a like action of the heat, until by
continuance thereof the semi-fluid metal thickens by degrees, loses its fusibility,
and becomes.converted into malleable iron, the actual conversion being termed
by workmen brought into nature; and it is supposed to be effected by the
dissipation and burning away of the carbon which the iron still retained after
the refining operation of the running-out fire or finery. As the conversion
proceeds and becomes complete; the iron, losing its fusibility, is said to become
dry, when it retains no fluidity, but gets into a crumbling or flakey state,
and then the charge of iron is collected into masses or lumps of a con-
venient size, and the 'fire being urged for a short time to bring the
metal to a white or welding heat, the masses_are_in_that_state_withdrawn-
one after another from the furnace, and welded solid by blows of a heavy
forge hammer called a stamping" or shingling hammer; and the rude mass
of solid malleablo iron so obtained, before it loses its heat, is passed repeatedly
between rollers, in order to reduce and flatten it to the shape of a rough bar.
Suchi bars are called puddled bars of malleable irôn. The hammering is some-
times dispensed with, and the masses of hot. iron, when withdrawn from the
puddling furnace, are passed between rough rollers, to effect the welding, and
then, by continuance of the rolling, the iron is formed into a puddle bar. The
rough puddle bars so obtained are afterwards cut up into short lengths, and
the pieces piled one upon another, to form suitable masses called piles, which

page_text: are heated to a welding, heat, or, as it is termed, reheated, in another air
furnace called a balling furnace or reheating furnace, and when withdrawn
therefrom are welded together into a solid mass by passing between. rollers,
and by continuance of the rolling the iron is formed into a finished bar of
malleable iron. And note, it has become a common practice in South Wales
to revive or smelt what is called slag, cinder, or scoria of iron, resulting from
the waste which the iron undergoes by oxydation in the several processes of the
art of making or manufacturing bar iron or malleable iron, as herein-before
enumerated; that is to say, slag, cinder, or scoria resulting from oxydation of
the heated iron, either in the operation of refining the crude iron in the
running-out fire or finery, or in the subsequent conversion into malleable iron
in the puddling process, or in the reheating in the balling or reheating furnace,
or in the operation of the forge hammer or rollers for welding the iron into
solid masses,
and forming those masses into puddle bars or finished bars. Such
slag, cinder, or scoria, being mixed with the native ore of iron or mine which
is put into the blast furnace, the iron in the slag, cinder, or scoria becomes
revived or smelted along with the iron contained in the native ore or mine, so
that the slag, cinder, or scoria which would otherwise be wasted becomes a
substitute for a part of the native ore of iron or mine which would otherwise
be required; but such use of slag, cinder, or scoria being found to impair the
quality of the iron which is so obtained, it is commonly found requisite, in
treating the same, to carry the refining operation of the running-out fire or
finery to its fully extent, in order that the refined metal or plate may be full.
blown, as a preparation for its subsequent conversion into malleable iron in the
puddling furnace. The use of slag, cinder, or scoria, as aforesaid, in the blast
furnace, in admixture with native ore of iron or mine, in lieu of a portion of
the ore or mine which would otherwise be used, produces a fusible quality of
cast or crude or pig iron, altho' otherwise inferior in quality; and it is not
found desirable to have so great a degree of fusibility in the metal which is
subject to the puddling process, because, as before mentioned, the metal is
partially melted or brought to a semi-fluid state when the aforesaid fermenta-
tion is excited and the conversion into malleable iron is effected. If the metal
is too fusible when first put into the puddling furnace, it will be quite melted
therein, and must remain a longer time exposed to the action of the current
of the flame, in order to thicken and acquire that consistency which is favorable
for the commencement of the fermentation.. The treatment of the metal in
the running-out fire or finery is endeavoured to be carried to that extent called
fullblown, or to any intermediate, state between that and what is called under-
blown, which is found, by experience, to be adapted to the quality of the crudo
or cast or pig iron, or mixtures of qualitics thereof, which is put into the:

page_text: running-out fire or finery, so as to obtain refined metal or plate, which in
respect to fusibility (conjointly with other qualities) is found most susceptible
of conversion into malleable iron in the puddling furnace. All the above
particulars are fully known to persons conversant with the iron manufacture;
but what is herein-before stated contains no part of my Invention, and is only
introduced by way of explanation of the meaning which I attach to the termis
which I use in describing my Invention.
My said improvement in the art of making or manufacturing bar iron or
malleable iron consists in adding to the iron which is undergoing the puddling
process in the puddling furnace rich native ore of iron in a state of powder,
throwing suitable small quantities thereof at a time into the puddling furnace
upon the semi-fluid iron, so that the said powder will become intermixed with
the said iron in consequence of the manipulation or action of turning over and
stirring up which the semi-fluid iron must receive during the usual course of
the puddling process; or, together with the said powder and rich native ore of
iron, I use charcoal, or else coal reduced to a state of powder, and intimately
mixed with the powder of ore; and suitable small quantities of such powder
of rich native ore of iron, either with or without powder of charcoal or coal,
being from time to time added to and intermixed with the semi-fluid iron, as
aforesaid, previous to the commencement of and during the progress of the
effervescence or fermentation herein-before mentioned, which precedes and
accompanies the conversion of iron into a malleable state, the said fermenta-
tion is increased, and the thickening of the iron is accelerated, and its coming
into nature, or conversion into the malleable state, is facilitated, so as in the
result to effect an improvement in the making or manufacturing of bar iron,
the beneficial result obtained by the improvement being in some cases that a
given weight of bar iron can be made by aid of the improvement from a less
quantity of crude or cast or pig iron than would be required in the ordinary
course of proceeding of refining the said iron in the running-out fire or finery,
and then puddling the refined metal or plate without the improvement, the
quality of the bar iron being as good in one way as the other. Or, in other
cases, the beneficial result will be, in making bar iron by aid of the improve-
ment of a superior quality to that which would be produced from the same
crude or cast or pig iron by the ordinary course of proceeding without the
improvement, the weight of crude or cast or pig iron required to make a given
weight of bar iron being the same in one way as the other. Or, in other
cases, the beneficial result will be in making bar iron by aid of the improve-
ment of a better quality from a smaller proportion of crude or cast or pig
iron than is done by the ordinary course of proceedure without the improve-
ment, my said improvement consisting as aforesaid in adding with native ore

page_text: of iron in powder, either with or without powder of charcoal or coal, and
mixing small quantities thereof from time to time with semi-fluid iron which
is undergoing the puddling process, so as by such addition and mixture to
increase the fermentation and accelerate the conversion of that iron into the
malleable state. My said improvement is supposed by me to operate by a
tendency which the rich iron ore may have to facilitate and expedite the
separation of carbon from the semi-fluid iron when the said ore is very sud-
denly heated by its application in small quantities, and in a divided state, to
the iron which is already in a semi-fluid state, and consequently very hot, and
that heat kept up by the continual action of the flame of the furnace. The
quantity of rich ore which is thrown in at once being small, its tendency to
lower the heat of the semi-fluid iron may be overcome in a great degree by
keeping up the fire strongly, and by the turning over and stirring manipulation
the powder is intimately mixed with the whole mass of semi-fluid iron as
quickly as possibly, and then the ore, becoming suddenly and strongly licated
I suppose it may facilitate and expedite the extrication of carbon from the
semi-fluid iron, for the addition of powder of iron ore, according to my im-
provement, visibly promotes and assists the intestine motion and effervescence
or fermentation which the semi-fluid iron usually undergoes, and which is
supposed to be occasioned by the departure of the carbon from the iron during
its conversion into the malleable state. But note, as the aforesaid supposition
of the ore operating beneficially by facilitating the extrication of carbon does
not admit of direct proof by any experiment which I have made, the same is
only offered as a supposition in explanation of the mode whereby my improve-
ment may produce those beneficial results which I have obtained from it in
many repeated trials on a large scale of actual practice. The iron which is
contained in the rich ore which, according to my improvement, is added to and
mixed with the semi-fluid iron, tends, as far as it goes, to increase the quantity
of malleable iron beyond that which would otherwise be produced without my
improvement, and also tends to improve the quality of the malleable iron, and
give the bars thereof a more fibrous texture than they would otherwise acquire.
And for the full explanation of the manner of performing my said Invention
I will now stato the mode of procedure which I have found by experience to be
most beneficial for making or maintaining bar iron or malleable iron by aid of
my improvement. The ore of iron which I employ for my improvement may
be of any kind which is rich in iron. I have used the rich iron ores obtained
in the Forest of Dean, in Gloucestershire, called brush ores, and which are
considered to be of the nature of hydrous oxydes of iron, containing about
sixty per cent. of their weight of metallic iron, and I have also used the rich

page_text: Cumberland iron ores, called blood-stone or hæmatites, from their red color,
and which are considered to be of the nature of oxydes of iron containing
more than sixty per cent. of iron; and I have also used the rich Lancashire
iron ores, which are considered to be of the same nature as the Cumberland
ores, but generally containing less iron, being from fifty to sixty-three per cent.
There are many kinds of rich iron ores obtained in foreign countries which
would answer the same purpose; but as it is not usual to import such ores of
iron in quantity into this country, I have not had an opportunity of making trial
of any foreign ore of iron, excepting one kind brought from the East Indies,
and which is used there for making the iron from which the East Indian steel
called wootz is made; but inasmuch as such rich foreign ores of iron would be
substituted for those obtained as aforesaid from Gloucestershire, Cumberland,
or Lancashire, such rich foreign ores of iron, as well as other rich ores of iron
which may possibly be obtained from other parts of Great Britain than those
which I have enumerated (although as yet unknown to me), will, I expect, be
available for carrying my Invention into effect, as the same does not depend upon
any peculiarity of the ore of iron which is used, provided that the same is rich
in iron, and free from (or separated from) any minerals which are inimical to
the reduction (by action of heat) of the iron contained in such ores into a
metallic state, and also provided that the said rich iron ore is capable of being
broken or ground to a state of powder. The rich ore of iron which I use is
to be reduced to powder small enough to pass through a wire sieve or riddle
containing about 300 holes or meshes in each square inch, but the finer the
powder the better it will operate, and hence if the nature of the ore will permit
of reducing it easily to a fine dust it will be advisable to do so. The ore may
be broken and powdered fine by stampers of the same kind as are commonly
used in Cornwall for reducing tin ores to powder, or it may be ground by
rolling stones called runners on edge, such as are used in the making of gun-
powder, or the iron ore may be crushed between iron rollers, or it may be
ground fine by the same kind of machinery which is commonly used by iron
founders for grinding charcoal, to make what they call moulders' blacking, for
applying to moulds in which iron is to be cast, and which machinery is well
known to all persons conversant with the iron manufacture. Or the iron ore
may be first crushed or broken small by one kind of machinery as aforesaid,
and then ground to fine powder by other kind of the said machinery, as is most
suitable for getting the iron ore into a state of minute division. The rich iron
ore which is used may be prepared by previous calcination or roasting; but I have
not found any sensible difference in the efficacy of the powder of Gloucestershire,
Cumbed und, or Fanca bire ore when the same have been prepared by roasting

page_text: or have been reduced to powder without roasting. Nevertheless, if a moderate
roasting will facilitate the breaking and grinding of the ore to powder, it may be
advisable to do so; but whether that will be the case or not will depend upon the
texture of the particular ore which is used, and the nature of the machinery which
is employed for breaking or grinding the ore; and in case powder of charcoal
or coal is to be mixed with the powder of rich iron ore, the same is to be ground
fine by any of the machinery before mentioned, that which is used for grinding
moulders' blacking being very suitable; and either charcoal of wood, or what is
called animal charcoal, may be used, the latter being commonly made from
bones, or from the hoofs of animals or scraps of leather. The proportions in
which I have found it advisable to use rich ore of iron in powder in the
puddling process, according to my improvement, are as follows:-To make
common bar iron, by aid of my improvement, I charge the puddling furnace
with about four hundred and fifty pounds weight of crude or cast or pig iron,
varying in quality from between what is designated bright grey and mottled,
approaching to white, mixing together such portions of the different qualities
which are within the range of variation as previous experience has pointed
out for producing an average quality in a long series of successive charges, so.
as to bring the operations of converting those successive charges into malleable
iron to regularity of repetition. And note, the selection of those said qualities,
and the proportions in which they are to be mixed together, and the said
average quality which it is desirable to produce, must be regulated by the
same judgment and discretion which is commonly exercised by ironmasters in
selecting and mixing the crude or cast or pig iron which is to be put into the
running-out fire or finery, when they intend to prepare the same for making
common bar iron without the aid of my improvement. Such judgment and
discretion can only be acquired by experience, and cannot be communicated by
writing, because of the numerous gradations of quality in crude or cast or pig
iron, which do not admit of accurate description; but it is sufficient to say
that the aforesaid charge of about four hundred and fifty pounds, which I put
into the puddling furnace, inay be of the same quality or mixture of qualities
of crude, cast, or pig iron as is usually put into the running-out fire or finery.
in order to be prepared for making common bar iron; but when the same bar
iron is to be made by aid of my improvement, the previous preparation or
refining by the running-out fire or finery may be dispensed with, and the crude
or cast or pig iron charged at once into the puddling furnace, as was formerly
practised by Mr. Cort during the term of his Patent of One thousand seven
hundred and eighty-four. The management of the puddling furnace is to be
the same as usually practised (that is to say)-Before it is charged the furnace

page_text: must be brought to a proper heat, and the iron bottom of the furnace prepared
in the usual manner for the reception of the charge, by laying on a proper
quantity of slag, cinder, or scoria, which has been separated from previous
puddle balls or reheated piles of puddle bars, by operation of the forge hammer
or rough rollers. But note, after the charge of iron is put into the puddling
furnace with its iron bottom so prepared, no more slag, cinder, or scoria is to
be thrown in during the operation of melting or converting the iron. When,
by the usual routine course of proceedure with puddling furnaces, the said
charge of crude, cast, or pig iron begins to bo melted, so as to be capable of
being stirred up and turned over with the iron tool which the workman uses
for that purpose, then the application of my improvement is to commence,
by throwing upon the partially melted iron about two pounds weight at a time
of powder of rich ore of iron, either with powder of charcoal or coal inter-
mixed or without, the iron being well stirred and turned over after every time
that a dose of powder is so thrown upon it, in order that the powder may
become intimately mixed with every part of the charge of iron. The fire
should be kept up, so that the heat of the iron will not become materially less
than would be desired in the usual practise, notwithstanding the throwing on
of the powder; and as soon as one dose of powder which has been thrown on
and mixed up with the iron appears together with the semi-fluid iron to be at
the full heat which the iron ought to have according to the ordinary process,
then another dose of about two pounds more of the same powder may be
thrown on, and mixed with the iron as before, and when the iron gets again
to a full heat, another like dose may be added, and so on, always turning over
and stirring the semi-fluid iron, and intermixing each small lose of the
powder as completely as possible with every part of the charge, and always
keeping up the heat of the iron to as near as can be to what would be done in
the usual way of puddling if my improvement were not used. And in this
I add about as much powder of iron ore as will amount by weight to
about one eleventh part of the weight of crude or cast or pig iron with which
the puddling furnace is charged, or about forty pounds weight of such powder
to the aforesaid charge of about four hundred and fifty pounds of iron; or in
case powder of charcoal or coal is intermixed with the said powder of ore, then
the weight of charcoal or coal will be at the rate of about one sixteenth part
of the weight of ore with which it is mixed, which will increase the said forty
pounds of powder to about forty-two and a half pounds to a charge of about
four hundred and fifty pounds of iron. The manner of adding the powder to
the semi-fluid iron will be the same, whether it contain a mixture of charcoal
or coal or not, except that it may be found expedient to wet or damp tho
way

page_text: powder which contains a mixture of charcoal or coal with water before
throwing it on. And note, such damping may be given when the powder does
not contain a mixture of charcoal or coal, if the workman finds it desirable,
all which is to be managed according to his experience in the working of the
iron and its heat; in the same manner and with the same discretion as water is
occasionally thrown into the puddling furnace in the ordinary course, of pro-
cecdure. The usual fermentation of the iron will be increased, and its con-
version into the malleable state, or coming into nature, will be facilitated, by
the addition of the powder, according to my improvement in manner afore-
said; and after that addition is made the process is to be continued and
concluded in the usual manner of puddling and inaking the iron into puddle
bars of common iron, without variation from the usual routine on account of
my improvement. I find that a ton or twenty hundredweight of puddle bars
can be made, in manner above explained, by aid of my improvement, from
twenty-one and a half hundredweight of crude, cast, or pig iron, or from
twenty and three quarters hundredweight thereof, when the powder of
rich iron ore is intermixed with powder of charcoal as above explained;
the quality of the puddle bars so made being the same common iron as
would be obtained by the usual mode of refining the crude, cast, or pig
iron in the running out furnace or finery, and then puddling the refined
metal or plate in the usual manner, without aid of my improvement. But
as that aid permits the preparatory refining operation to be dispensed with, a
great saving of waste is attained; and although I have stated one eleventh of
the weight of the charge of crude, cast, or pig iron as a proportion for the
powder of rich iron ore which may be used, the same may be varied with
advantage in different cases, from one eleventh to one eighteenth, according to
the nature and fusibility of the iron, and that if the rich ore which is used;
the proportion for every particular sort of iron and of ore can only be deter-
mined by the discretion of the ironmaster, taking experience for his guide.
To make bar iron of a first-rate quality by aid of my improvement, I take
crude, cast, or pig iron, of a richer quality than is usually employed for con-
verting into malleable iron, being such as is used by ironfounders, and
commonly called No. 2, grey iron foundry metal, and which metal has been
made without putting any slag, scoria, or ciñders into the blast furnace. The
mode of proceedure is to be the same as last explained, putting a charge of
about four hundred and fifty pounds of such No. 2 grey iron into the puddling
furnace, and adding thereto about one-eighth part of its weight, or about
fifty-five pounds of powder of rich iron ore, applying the same in successive
small doses, in manner herein-before described, which will assist the fermenta-

page_text: tion, and facilitate the conversion into malleable. iron. And. I find that a ton
or twenty-hundredweight of puddle bars of the first-rate quality can. be made
in that way by aid of my improvement from about twenty-one hundredweight
and three quarters of the said No. 2 crude, cast, or pig iron, which is put into
the puddling furnace, or, from about twenty-one hundredweight thereof if
powder of charcoal is intermixed with the powder of rich iron ore, the weight
of powder of charcoal being about one-sixteenth of the weight of the powder
of ore with which it is mixed. And although by.aid of my improvement the
use of the running-out fire or finery may be dispensed with, and Mr.. Cort's
original practice of puddling crude, cast, or pig iron, as it comes from the blast
furnace, may, by aid of my improvement, be rendered. fully available in prac
tice, nevertheless my improvement is applicable with advantago to, the
puddling and conversion of refined metal or plate into bar iron or malleablo
iron. In such case I take such refined. imetal or plate: as would be-usually
denominated. underblown; and which in undergoing the operation of the
running-out fire or finery will have lost in weight from eight to ten cent of
the weight of the crude or cast or pig iron.which was put into the running
out fire or-finery, and of such underblown refined metal or plate I put into the
puddling furnace a charge of about four hundred and fifty pounds, and add
thereto about one-twentieth part of its. weight, or about twenty-five pounds of
powder of rich iron ore, applied in small successive doses, in manner herein-
before described; and I find that a ton or twenty hundredweight of puddle.
bars can be made in that way from about twenty hundredweight and threo
quarters of the refined metal or plate which was put into the puddling furnace;
or from only twenty hundredweight thereof (or even less) when the said
powder of rich iron ore is intermixed. with about one-sixteenth part. of its
weight of powder of charcoal, in manner already, explained, and, the quality of
the bar iron thus made by aid of my improvement will be found equally
fibrous as if it had been made in the common. mode without any improvement.
Or in-applying my improvement in case of puddling refined metal or plate
which has been fully blown by previous operation of the running-out fire or finery:
put
about four hundred and fifty pounds thereof into the puddling: furnace,
and add about one-thirtieth part of its weight of powder of rich iron ore, or
about fifteen pounds thereof to the said charge; and in case such refined.
metal with such addition should not be found. to melt so thin as is desirable for
the proper working of the iron in the furnace, then from thirty to sixty pounds.
or more of grey inclting iron may be mixed with the refined metal or plato
when the furnace is charged; and the said four hundred and fifty pounds.
being made-up by so mixing will have acquired more fusibility; and I find
I

page_text: that a ton or twenty hundredweight of puddle bars can be thus made by
aid of my improvement from about twenty hundredweight and three quarters
of fully blown refined metal or plate, or from about twenty hundredweight and
one quarter thereof, when powder of charcoal at the rate of about one
sixteenth part of the weight of the powder of iron ore is intermixed therewith,
as before explained. Or for applying my improvement in case of puddling a
mixture of equal parts of fully blown refined metal or plate, and of crude,
cast, or pig iron, which has not been subjected to the operation of the
running-out fire or finery, I put a charge of about four hundred and
fifty pounds of such mixture into the puddling furnace, and add thereto
about one fifteenth of the weight of the charge, or thirty pounds of powder
of rich iron ore; and I find that a ton or twenty hundredweight of puddle bars
can be made in that way from about twenty one hundredweight of the afore-
said mixture of iron which was put into the puddling furnace, or from about.
twenty hundredweight thereof (or even less) when powder of charcoal is
mixed with the powder of ore in manner aforesaid. And although I have
mentioned the proportions of powder of iron ore, with or without mixture of
powder of charcoal, which I have found to answer best for performing my.
improvement with effect in several cases which will be found to comprize the
most usual circumstances of the manufacture of bar iron, nevertheless those
proportions must be varied to suit various circumstances; and as some guide
to those variations it may be observed, that the more fusible the iron is which
is put into the puddling furnace so a greater proportion of the powder of rich
iron ore may be used with advantage for the performance of my improvement;
but if a greater quantity of such powder is added than is suitable to the fusi-
bility of the iron, it will thicken too much, and partially so as to agglutinate
into lumps which are unmanageable and that should be avoided; and, on the
other hand, if the iron does not thicken so soon or become converted into the
malleable state as quickly as it might do and as is desirable, or, as the work-
men say,
if it continues too long wet, then by adding more of the powder of
such iron ore it will thicken or become dry and ready for withdrawing from
the furnace, the tendency of adding powder of iron ore according to my
improvement being in all cases to expedite the conversion of the iron into a
malleable state in the puddling furnace. And when powder of charcoal or coal
is intermixed with powder of rich iron ore, as herein-before explained, the
proportion herein-before stated of the powder of charcoal being one-sixteenth
of the weight of the powder of iron ore, I have found to answer the purpose;
but that proportion may be varied. And respecting the application of my
improvement in cases of puddling crude or cast or pig iron which has been

page_text: made by putting slag, cinder, or scoria along with ore or mine into the blast
furnace according to a practice before explained, although the same may
be puddled without an absolute necessity for a previous preparation in the
running-out fire or finery, nevertheless I prefer and recommend that such pig
or crude or cast iron should be prepared by the operation of the running-
out fire or finery, and thereby blown or refined to such a degree as may be
most suitable to its peculiar quality, in the same manuer as is now commonly
practised with such metal, and then to charge the puddling furnace with such
refined metal, and to apply my improvement during the process of puddling
the same in the manner herein-before directed for puddling refinered metal or
plate.
Having now described the nature of my my improvement, and the manner
in which the same is to be performed, I, the said David Mushet, do hereby
declare, that the new Invention whereof the exclusive use is granted to me by
the said Letters Patent consists in adding rich native ore of iron in powder (either
with or without intermixture of powder of charcoal or coal) to iron which is
undergoing the process of puddling in the puddling furnace, in order to be by
that process converted into the malleable state and manufactured into bar iron.
In witness whereof, I, the said David Mushet, have hereunto set my
hand and seal, this Twenty-second day of April, One thousand eight
hundred and thirty-six.
Inrolled the Twenty-second day of April, in the year of our Lord Onc
thousand eight hundred and thirty-six.