IMPROVE- MENTS IN PUDDLING FURNACES
Year: 1866

page_text: LETTERS PATENT to William Clark, of 58, Chancery Lane, in the County
of Middlesex, Engineer and Patent Agent, for the Invention of "IMPROVE-
MENTS IN PUDDLING FURNACES."-A Communication from abroad by Chris-
topher De Graff Baker, Jacob Harlan, and Joseph Bell, all of Wheeling,
Ohio County, State of West Virginia, United States of America.
Sealed the 18th January 1867, and dated the 17th August 1866.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
17th August 1866.
I, WILLIAM CLARK, of 58, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PUDDLING FURNACES," to be as follows:-
This Invention relates to improvements in the construction of puddling
furnaces for the manufacture of iron, embracing novel arrangements and
devices applied to both single and double furnaces, the design of which
improvements has reference to economy in the cost of construction and main-
taining the furnace in working order, and to the economical working of the
iron, both in respect to the consumption of coal and the application of labor,
and also in the actual effective influence on the iron itself.
The devices and arrangements by which these ends are accomplished
consist of an improved construction of the chill and the iron bed in the
puddling chamber, in the location of the chimney and exit flue relatively to

page_text: the iron or boiling chamber, and in the structure or form of the exit flue;
also in constructing the entire furnace above ground and dispensing with a
large portion of the brickwork hitherto required and used, by which means
the expense of building is reduced materially, and the time required to build
it diminished;
also in providing a raised border or chill of the iron chamber
with a channel, passage, or groove running through it for receiving water or
air, which is supplied at intervals in order to preserve the chill from injury in
consequence of the intense heat to which it is exposed; also in constructing
a chill of wrought iron; also in a novel method of arranging the fire-grate
relatively to the iron chamber, which arrangement tends to save fuel, reduces
the size, and hence lessens the cost of the fire bridge; also in an improved
method of arranging and constructing the stack in connection with the furnace,
which enables me to dispense with a portion of the throat or neck of the exit
flue between the stack and the iron chamber; also in constructing the furnace
with passages or spaces wherein the surplus air or steam from the grooves or
steam and air channels in the chill is conducted off and discharged into the
open air; and also in the means for joining or building two furnaces back to
back to form a double furnace, and several other novel devices and improve-
ments. The furnace is constructed generally in the usual manner of iron and
fire-brick.
The treatment to which iron is subjected in the process of puddling in
furnaces of this class is too well known to require any explanation herein;
but before proceeding with the description of this improved furnace it is
proper to refer to one part of the operation. For boiling or puddling iron it
is necessary to prepare the bed of the furnace, which is a thick plate of cast
iron, and the surrounding sides to protect them from the direct intense action
of the fire. The common practice of preparing the bed to resist the heat is to
burn or melt a quantity of wrought iron, say, about one hundred pounds of
scrap, to a cinder, as it is technically called, upon the bottom, to which it
adheres, forming a coating, say, two inches in thickness; this works out
generally every day in the course of six heats, which is a common day's task,
and it must therefore be renewed every day. It is usual to pile lumps of iron
ore or slag around the edges of the chill to protect them, using about five
hundredweight daily for the purpose, one-half of which may be saved by one
of these improved modes of construction. This improvement consists, firstly,
in raising the edges of the bed plate, which is generally flat, and reducing the
beight of the chill correspondently, so that the quantity of ore required for
its protection is also greatly reduced; and, secondly, by flaring the chills
outwardly, so that the pile of ore raised against them maintains its position

page_text: better and does not wasto away so rapidly. Though the exact measurements
of these modifications of form of the bed plate and the chills are not essential,
I will state here that I raise the edges of the bottom about one and a half
inches, beginning the rise at a point, say, about three inches from the margin,
except at the furnace door, and I make the chills flare outwardly about the
same.
Another improvement which I have made in the construction of the chills
consists in forming a channel or groove through them for the circulation of
water around the margin of the chamber, which is supplied at the pleasure of
the puddler according to the necessity for protection against the heat by means
of a hose or otherwise; or, if preferred, the chill may be cast hollow, and
instead of water cold air may be forced through it by the blower usually con-
nected with a furnace, or in any desired mauner, and discharged beneath the
fire chamber, for the purpose of preserving the chill from the injurious effects
of the intense heat to which it is subjected. The channel or groove running
through the chill I place in connection with a series of passages made in the
brickwork of the front and back of the furnaces for conductors to carry off the
steam generated in the chills, which enters at the lower ends and passes off at
the top of the furnace. I have also succeeded in making a chill of wrought
iron, which I have proved to be much superior to cast iron, for the reason that
it withstands the action of the intense heat better. The wrought-iron chill
can be made by forging or rolling. By constructing a chill in accordance
with the above description I am enabled to dispense entirely with the use of
oro, which is generally employed for its protection against contact with the
melted metal.
Another of these improvements, by which very important results are
effected relates to modifications in the form and construction of the throat or
nock of the stack in its connection with the puddling chamber. The neck of
the flue has a narrow throat presented to the chamber so as to cause the
reverberation of the flame to be confined therein, and is so formed as to allow
the volatile products of combustion to pass away in a direction approximating
by a gradual rise to the line of their final escape up the chimney instead
of being deflected downwardly over a bridge as usual. The draft is thus
regulated by the number of square inches in the aperture of the throat instead
of regulating it by means of what is called in the trade a "velvet tree," which
consists of an arch in the stack at the point where the volatile products of
combustion are deflected upwardly into the chimney. At this point the clay
which melts behind the fire bridge, together with the cinders and detritus from
the inside of the chimney, collect and form into a slag which has to be
'

page_text: removed generally once a week, involving the necessity of knocking down the
"take-up" or that portion of the brickwork beneath an arch in the back of
the chimney; this constantly repeated operation jars and unsettles the stack.
I avoid this necessity by making the bottom or floor of the neck flue and the
continuation of it into the stack rising or inclining upwards from the aperture
of the throat of the boiling chamber, by which conformation of the flue bottom
the melted clay and the detritus and slag which collect from the chimney will
work their way back into the boiling chamber where they are taken out from
time to time by being collected on the hooks from the surface of the molten
iron, the hooks being plunged into water when the slag breaks off, and is thus
disposed of without knocking a hole in the chimney, as in the old plan, and
getting it out with a sledge and crowbar. According to the ordinary construction
the stack is placed some distance away from the puddling chamber, say, about
three feet six inches, and they are connected by a neck through which the
flue passes, requiring a separate section of fire brick to build it. Now in
erecting the furnace on this plan I set it close up against the stack and form
the inclined floor in the brickwork, which constitutes the base of the stack
itself, and thus I dispense with the neck connection and save the cost of material
and labor in building it. It is usual in building puddling furnaces to strike
a centre line from the middle of the chimney in the plan through the
middle of the furnace, and then make a lining of fire-brick inside of the
binding plates of thirteen inches thick on the back side opposite the door, and
nine inches on the front side adjacent to the door, tapering away to nothing at
the sides of the door, so that the ravels and paddles which are introduced
through the stopper hole to stir and work the iron may reach all parts of the
chamber. Owing to this irregularity in the sides of the chamber the flame is
unequally directed upon the iron, and is too much deflected away from the
'door, which is precisely the point where the heat is most required to prevent
the cooling effect of the air which enters through the stopper hole directly on
the iron. Now I place this stack in such relation to the furnace that the
central line of the fire and boiling chamber is identical with the central line
of the stack flue, notwithstanding the disparity referred to in the thickness of
the lining of the front and back parts of the furnace, and so that the flames
are not deflected from the iron near the door. This improved furnace there-
fore is built not exactly in line with the centre of the stack, but in such
relation to it that the puddling chamber has the requisite central position for
causing the flames to reverberate and deflect equally upon all parts of the
charge of metal, the effect of which is uniformity and improvement in the
quality of the iron. The necessity for contracting the width of the puddling

page_text: chamber in order that the ravels and paddles shall reach the iron in the back
part occasions the disparity mado in the thickness of the lining of the two
sides in the ordinary plan of construction. But by this improved plan of
construction, making the stack flue bear a central relation to the fire and
puddling furnaces instead of to the body of the furnace itself in its exterior
plan, I meet and overcome this necessity; and as a further and more
important corelative result I am enabled to reduce very materially the size
of the furnace and the puddling chamber without impairing its efficiency, but
with decided advantage in the working of the iron and the consumption of
fuel. By this material reduction in the dimensions of the furnace and the
chambers its capacity for making iron is in no wise diminished; and I will
briefly refer to some of the practical benefits derived from this improvement.
I have before spoken of the saving of coal, which is under all circumstances
a heavy item of cost of production. The diminished size of the furnace is
directly utilized by the corresponding reduction of cost of labor and materials
in construction, and also of time required, which is often an important element
of value in the calculation of cost. The facility for handling the iron is very
materially enhanced by the contraction of the area of the floor of the puddling
chamber, while there is abundant room for the usual charge of iron and for
balling.
Another of these improvements in the construction of puddling furnaces
consists in building them entirely above ground. Heretoforo the common
practice has been to dig an ash-pit in the earth, making it necessary to.use &
large quantity of fire-brick for the foundation to be laid several feet below tho
level of the ground. In erecting a singlo furnace I employ for tho purpose
of a foundation support two heavy metal plates or bars, which are laid parallel
to each other flat upon the surface of the ground. To prevent them from
being displaced from the position in which they are set a projecting flange is
made on one or both edges, which is let into the ground. The front and back
binding plates rest upon these foundation plates, which may be formed with
shoulders on the top for the plates to lio between to prevent lateral displace-
ment. I also raise the fire chamber, and place the grate on a level with the
top of the chill in the puddling chamber instead of one foot below where the
fire-grato is usually located. The fire-grate is also generally placed about
18 inches back from the chill, the intermediate space being built up with fire-
brick, and forming what is called the fire bridge. For this purpose from
75 to 80 fire-bricks are commonly used. It is manifest that by raising the
grate up to be about level with the top of the chill and setting it close against
it that the fire bridge will be greatly reduced in size vertically and horizontally,

page_text: and that consequently instead of requiring from 75 to 80 fire-bricks to build it
from ten to fifteen bricks will suffice. By this method of arranging the fire-
grate the action of the fire is more direct upon the iron in the puddling
chamber, and consequently more effective, thus contributing to the general
economy both in construction and operation.
I will now describe the improved method of joining two furnaces back to
back. The front and back walls I make of nine-inch brickwork conjoined
with binding plates. By uniting two furnaces in the manner three binding
plates only are required, the central plate serving as the back binding plate for
each furnace. In a single furnace constructed upon this improved plan both
the front and back binding plates extend down to the foundation or to the
supporting or foundation bars which rest upon the ground, but when two
furnaces are joined together as described the binding plate which serves for
the back of each extends down only as far as the bottom plate of the puddling
chamber, in which case the furnaces are both supported at the back by legs,
which may be bolted to the bottom plates. I extend the fire-brick from the
top of the furnace as far down only as the top of the chill instead of to the
bottom or foundation of the furnace from two to three feet below the ground,
as customary in building furnaces on the old plan. On each side of the
lining or central column of the stack in double furnaces the side walls abut
against the front and back parts, which walls are in fact the main columns and
support of the stack, and require a large quantity of brick to build them.
Four walls are usually required to render the erection of one of them un-
necessary, and save the cost of building. I erect one midway between the
two stacks, which serves for both furnaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
16th February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of August, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, er heirs and successors, givo and grant unto me, the
said William Clark, Her special licence that 1, the said William Clark, my

page_text: executors, administrators, and assigns, or such others as I, the said William
Clark, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PUDDLING
FURNACES," a communication to me from abroad by Christopher Do Graff
Bakor, Jacob Harlan, and Joseph Bell, all of Wheeling, Ohio County, State
of West Virginia, United States of America, upon the condition (amongst
others) that I, the said William Clark, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Clark, do hereby declare the
naturo of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say):
:-
This Invention relates to improvements in the construction of puddling
furnaces for the manufacture of iron, embracing novel arrangements and
devices applied to both single and double furnaces, the design of which
improvements have reference to economy in the cost of construction and
maintaining the furnace in working order, and to the economical working of
the iron both in respect of the consumption of coal and the application of
labor, and also in tho actual effective influence on the iron itself.
The devices and arrangements by which these ends are accomplished
consist of an improved construction of the chill and the iron bed in the
puddling chamber, in the location of the chimney and exit flue relatively to
the iron or boiling chamber, and in the structure or form of the exit flue;
also in constructing the entire furnace above ground and dispensing with a
largo portion of the brickwork hitherto required and usod, by which means
the expense of building is reduced materially and the time required to build it
diminished; also in providing a raised border or chill of the iron chamber
with a channel, passage, or groove running through it for receiving water or
air which is supplied at intervals in order to preserve the chill from injury in
consequence of the intenso heat to which it is exposed; also in constructing
a chill of wrought iron; also in a novel method of arranging the fire-grate

page_text: relatively to the iron chamber. which arrangement tends to save fuel, reduces
the size, and hence lessens the cost of the fire bridge; also in an improved
method of arranging and constructing the stack in connection with the
furnace, which enables me to dispense with a portion of the throat or neck
of the exit flue between the stack and the iron chamber; also in constructing
the furnace with passages or spaces wherein the surplus air or steam from
grooves, or steam and air channels in the chill, is conducted off and discharged
into the open air; and also in the means for joining or building two furnaces
back to back to form a double furnace, and several other novel devices and
improvements. The furnace is constructed generally in the usual manner of
iron and fire-brick.
Figure 1 of the annexed Drawings represents an outline perspective view of a
puddling furnace; Figure 2 is a longitudinal vertical section taken in the plane
of the line x, x, Figure 1; Figure 3 is a transverse vertical section taken in the
plane of the line y, y, Figure 1; Figure 4 is a horizontal section of a double
furnace of this Invention, back to back, upon an improved plan, taken in the
plane of the line z, z, Figure 5; Figure 5 is a longitudinal vertical section taken
in the plane of the line w, w, Figure 4; Figure 6 is a transverse section of the
double furnace of this Invention, represented by Figure 4, taken in the plane
of the line v. Similar letters of reference indicate corresponding parts.
A represents the fire chamber; B, the iron or puddling chamber; C is the
exit flue or throat of the chimney; D, the stack; E, E, are the iron binding
plates which form the exterior walls and confine the fire-brick that line the
furnace and form the roof or top; F, the grate bars; G is the stack hole for
introducing fuel; H, the door of the iron chamber; I, the stopper hole; :
J, the tap hole; K, the fire bridge; L, the air chamber and ash-pit below;
and M, the iron plate which forms the bed or floor of the puddling chamber.
The treatment to which iron is subjected in the process of puddling in
furnaces of this class is two well known to require any explanation herein,
but before proceeding with the description of this improved furnace it is proper
to refer to one part of the operation.
For boiling or puddling iron it is necessary to prepare the bed of the
furnace, which is a thick plate of cast iron, and the surrounding sides, to
protect them from the direct intense action of the fire. The common practice
of preparing the bed to resist the heat is to burn or melt a quantity of wrought
iron, say, about one hundred pounds of scrap, to a cinder, as it is technically
called, upon the bottom to which it adheres, forming a coating, say two
inches in thickness; this works out principally every day in the course of six
heats, which is a common day's task, and it must therefore be renewed every

page_text: day. It is usual to pile lumps of iron ore or slag around the edges of the chill
to protect them, using about five hundredweight daily for the purpose, one-
half of which may be saved by one of these improved modes of construction.
This improvement consists, first, in raising the edges of the bed plate, which
is generally flat, and reducing the height of the chill correspondingly, so that
the quantity of oro required for its protection is also greatly reduced; and,
secondly, by flaring the chills outwardly so that the pile of ore raised against
them maintains its position better and does not waste away so rapidly.
Though the exact measurements of these modifications of form of the bed
plate and the chills are not essential I will state bere that I raise the edges of
the bottom about one and a half inches, beginning the rise at a point, say,
about three inches from the margin except at the furnace door, and I make
the chills flare outwardly about the same.
These improvements in the construction of the chills and bed plate are
represented in the Drawings at Figures 2 and 3.
Another improvement which I have made in the construction of the chills
consists in forming a channel or groove through them for the circulation of
water around the margin of the chamber, which is supplied at the pleasure of
the puddler, according to the necessity for protection against the heat, by means
of a hose or otherwise, or if preferred, the chill may be cast hollow, and instead
of water cold air may be forced through it by the blower usually connected
with the furnace, or in any desired manner, and discharged beneath the fire
chamber for the purpose of preserving the chill from the injurious effects of
the intense heat to which it is subjected. In Figures 5 and 6, N represents
the chill, and a the channel or groove running through it. In connection
therewith I make in the brickwork of the front and back of the furnaces
a series of passages R, R, for conductors to carry off the steam generated in
the chills, which enters at the lower ends and passes off at the top of the furnace;
I have also succeeded in making a chill of wrought iron, which I have proved
to be much superior to cast iron, for the reason that it withstands the action
of the intense heat better. The wrought-iron chill can be made by forging
or rolling. By constructing a chill in accordance with the above description
I am enabled to dispense entirely with the use of ore, which is generally
employed for its protection against contact with the melted metal.
Another of these improvements, by which very important results are effected,
relates to modifications in the form and construction of the throat or neck of
the stack in its connection with the puddling chamber. The neck of the flue
has a narrow throat presented to the chamber, so as to cause the reverberation
of the flame to be confined therein, and is so formed as to allow the volatile

page_text: products of combustion to pass away in a direction approximating by a gradual
rise to the line of their final escape up the chimney instead of being deflected
downwardly over a bridge as usual. The draught is thus regulated by the
number of square inches in the aperture of the throat instead of regulating it
by means of what is called in the trade a "velvet tree," which consists of an
arch in the stack at the point where the volatile products of combustion are
deflected upwardly into the chimney. At this point the clay which melts
behind the fire bridge, together with the cinders and detritus from the inside
of the chimney, collect and form into a slag which has to be removed generally
once a week, involving the necessity of knocking down the "take up," or that
portion of the brickwork beneath an arch in the back of the chimney; this
constantly repeated operation jars and unsettles the stack. I avoid this
necessity by making the bottom or floor of the neck flue and the continuation
of it into the stack rising or inclining upwards from the aperture of the throat
of the boiling chamber, as represented in the Figures 2 and 5, by which conforma-
tion of the flue bottom the melted clay and the detritus and slag which collect
from the chimney will work their way back into the boiling chamber, where
they are taken out from time to time by being collected on the hooks from
the surface of the molton iron, the hooks being plunged into water when the
slag breaks off, and is thus disposed of without knocking a hole in the chimney,
as in the old plan, and getting it out with a sledge and crowbar. I have
heard it remarked that this costs nothing, as it is the business of the "boiler"
to keep his furnace in order, and the work of tearing down a portion of the
stack and replacing it is generally done on Sunday when the fire is out and
the works are not in operation, but such an argument against an innovation
which saves labor and time to the workman is as unsouud in morals as in
political economy. If the extra work is not paid for by the ironmaster
directly it must be in the long run, or the laborer will be defrauded, and I
have demonstrated practically that this rude practico is unnecessary, and is
obviated by this improved plan of constructing the flue with the floor inclining
upward into the stack.
In the general modification of proportious and modes of constructing
puddling furnaces according to these several improvements to be herein-after
more particularly described I change the position of the stack with reference
to the boiling chamber in such manner as to effect another important
alteration in the throat or neck of the stack, while at the same time retaining
the advantages of the inclined form of the bottom just described, which is
applicable to the ordinary plan of constructing the stack relatively to, the
position of the puddling chamber.

page_text: According to the ordinary construction, as shown in Figures 1 and 2, tho
stack is placed some distance away from the puddling chamber, say about
three feet six inches, and they are connected by a neck through which
the flue passes, requiring a separate section of fire-brick to build it. Now
in erecting the furnace on this plan I set it close up against the stack, and
form the inclined floor in the brickwork which constitutes the base of the
stack itself, as shown in Figures 4 and 5, and thus I dispense with the neck
connection and save the cost of material and labor in building it. Many
practical advantages are gained by those improvements which will readily
commend themselves to the worker in iron.
As a result I am enabled to run off the usual daily duty of the furnace,
say two thousand eight hundred pounds of iron in six heats, with eight to ten
bushels less of coal than is ordinarily required. I ascribe this saving of coal
mainly to the fact that the draught is more perfect, while also the reverberation
of the flames is confined to the boiling chamber and operates on the iron
more effectively. It is usual in building puddling furnaces to strike a centre
line from the middle of the chimney in the plan through the middle of the
furnace, and then make a lining of fire-brick inside of the binding plates of
thirteen inches thick on the back side opposite the door, and nine inches on
the front sido adjacent to the door, tapering away to nothing at the sides of
the door, so that the ravels and paddles which are introduced through the
stopper hole to stir and work the iron may reach all parts of the chamber.
Owing to this irregularity in the sides of the chamber, the flame is unequally
directed upon the iron, and is too much deflected away from the door, which is
precisely the point where the heat is most required to prevent the cooling effect
of the air which enters through the stopper hole directly on the iron. Now I
place tho stack in such relation to the furnace that the central line of the fire and
boiling chamber is identical with the central line of the stack flue, notwithstand-
ing the disparity referred to in the thickness of the lining of the front and back
parts of the furnace, and so that the flames are not deflected from the iron near
the door. This improved furnace therefore is built not exactly in line with the
centre of the stack, but in such relation to it that the puddling chamber has tho
requisite central position for causing the flames to reverberate and deflect
equally upon all parts of the charge of metal, the effect of which is uniformity
and improvement in the quality of the iron. The necessity for contracting
the width of the puddling chamber in order that the ravels and paddles shall
reach the iron in the back part occasions the disparity made in the thickness
of the living of the two sides in the ordinary plan of construction. But by
this improved plan of construction making the stack flue bear a central relation

page_text: to the fire and puddling furnaces instead of to the body of the furnace itself in
its exterior plan I meet and overcome this necessity, and as a further and moro
important correlative result, I am enabled to reduce very materially the size of
the furnace and the puddling chamber without imparing its efficiency, but with
decided advantage in the working of the iron and the consumption of fuel.
Without stating that the dimensions and proportions of boiling furnaces are
by any means universal and exact, I have found them generally, to be about as
follows:-The puddling chamber six by five feet, the fire chamber four by three
feet ten inches, and the flue to the stack sixteen by sixteen inches with a throat
aperture at the face of the flue bridge of twenty-two by nine inches. I
contract the size of this puddling chamber to five by four feet, and by placing
the draught aperture at the entrance of the flue I make that the regulating
point and reduce it to sixteen by seven inches, while at the same time the
fire chamber is reduced to three by two feet ten inches. By this material
reduction in the dimensions of the furnace and the chambers its capacity for
making iron is in nowise diminished, and I will briefly refer to some of the
practical benefits derived from this improvement. I have before spoken of
the saving of coal which is under all circumstances a heavy item of cost of
production. The diminished size of the furnace is directly utilized by the
corresponding reduction of cost of labor and materials in construction, and
also of time required, which is often an important element of value in the
calculation of cost. The facility for handling the iron is very materially
enhanced by the contraction of the area of the floor of the puddling chamber
while there is abundant room for tho usual charge of iron and for balling.
But as I am addressing myself to experts I do not deem it necessary to
enlarge on this subject, they all know what hard and incessant labor it is to
keep the iron well worked and turned in every part of the charge alike, and
that its quality as well as the quantity turned out depends upon the method
and skill with which the ravels and paddles are handled, while the labor
required of the workmen to perform the work thoroughly equally depends upon
bis control and power over the tools. In turning the iron his great art is to take
advantage of the leverage upon the paddle, which leverage is much increased in
his favor, inasmuch as the far sides and ends of this improved puddling chamber
are so much nearer to the stopper holo through which the paddle is introduced.
Another one of my improvements in the construction of puddling furnaces
consists in building them entirely above ground. Heretofore the common
practice has been to dig an ash-pit in the earth, making it necessary to use a
large quantity of fire-brick for the foundation to be laid several feet below the
lovel of the ground. '

page_text: In erecting a single furnaco I employ for the purpose of a foundation
support two heavy metal plates or bars T, T, Figure 6, which are laid parallel
to each other flat upon the surface of the ground. To prevent them from
being displaced from the position in which they are set a projecting flange b
is made on one or both edges, which is let into the ground. The front and
back binding plates E, E, rest upon these foundation plates T, T, which may
bo formed with shoulders c, c, on the top for the plates to set between to
prevent lateral displacement. I also raise the fire-chamber and place the
grate T on a level with the top of the chill N in the puddling chamber B, as
represented by Figure 5, instead of one foot below where the fire-grate is
usually located; the fire-grate is also generally placed about eighteen inches
back from the chill, the intermediate space being built up with fire-brick, and
forming what is called the fire bridge; for this purpose from seventy-five to
eighty fire-bricks are commonly used. It is manifest that by raising the grate
up to be about level with the top of the chill and setting it close. against it
that the fire bridgo will be greatly reduced in size vertically and horizontally,
and that consequently instead of requiring from seventy-five to eighty fire-
bricks to build it from ten to fifteen bricks will suffice. By this method of
arranging the fire-grate the action of the fire is more direct upon the iron in
the puddling chamber and consequently more effective, thus contributing to
the general economy both in construction and operation.
I will now described my improved method of joining two furnaces back to
back in the manner represented in Figures 4, 5, and 6. The front and back
walls P, P, I make of nine-inch brickwork, conjoined with the binding plates
E, E. By uniting two furnaces in the manner clearly shown in the Drawings
three binding plates only are required, the central plate serving as the back
binding plato for each furnace.
In a single furnace constructed upon this improved plan both the front and
back binding plates extend down to the foundation or to the supporting bars
T, T, which rest upon the ground; but when two furnaces are joined together
as represented the binding plate which serves for the back of each extends
down only as far as the bottom plate of the puddling chamber, in which caso
the furnaces are both supported at the back by the legs S, S, which may be
bolted to bottom plates in the manner shown in Figure 6. I extend the
fire-brick from the top of the furnace as far down only as the top of the
chill N, as shown in Figure 6, instead of to the bottom or foundation of the
furnace from two to three feet below the ground, as customary in building
furnaces on the old plan. On each side of the "lining" or central column of
tho stack D in double furnaces side walls O abut against the front and back

page_text: I
part, which walls aro in fact the main columns and support of the stack, and
require a large quantity of brick to build them. Four walls are usually
required to render the erection of one of them unnecessary and save the
cost of building, I erect one midway between the two stacks, as shown in
Figure 4, which serves for both furnaces.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to bo
protected by the herein-before in part recited Letters Patent is,―
1st, I claim the general arrangement of puddling furnaces, embracing the
several improvements in the plans and methods of construction, substantially
in the manner and for the purposes herein described, and as represented in
the Drawings.
2ndly, placing the puddling chamber in the relative position to the exit
flue, as and for the purposes described.
3rdly, inclining the floor or bottom of the exit flue upward from the
puddling chamber, in the manner and for the purposes specified.
4thly, forming the throat or regulating point at the entrance to the
neck or exit flue, so as to confine the reverberating flames to the chamber
itself.
5thly, raising and shelving the margin of the iron bod of the puddling
chamber upward, in the manner and for the purposes herein specified.
6thly, flaring or shelving outwardly the "chill" or border of the puddling
chamber, as and for the purposes herein described.
7thly, constructing a puddling furnace entirely above ground, substantially
in the manner and for the purposes herein set forth and represented in the
Drawings.
8thly, surmounting the puddling or iron chamber with fire-brick, substan-
tially as and for the purpose set forth.
9thly, surmounting both the iron and the fire-chambers with fire-brick,
substantially as and for the purpose specified.
10thly, providing the iron "chill" with a groove, passage, or chamber for
conducting water or air through and around it, substantially as and for the
purposes herein described.
11thly, constructing the chill of the iron chamber of wrought iron, as
described.
12thly, arranging the fire-grate relatively to the iron chamber in the position
and manner substantially as and for the purposes specified.
18thly, placing the stack close up against the furnace, in the manner and
for the purpose set forth.
g

page_text: 14thly, forming passages in the brickwork of the furnace for carrying off
steam and air from the grooves or channels in the chill, constructed and
arranged substantially as and for the purposes herein described.
15thly, joining two furnaces back to back, in the manner and for the
purposes substantially as herein described.
16thly, the combination and arrangement of three main walls with two
stacks, substantially as and for the purposes herein described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Fifteenth day of February, in the year of our Lord
One thousand eight hundred and sixty-seven.
Witness,
JAMES DAISH,
53, Chancery Lane,
London.
W. CLARK. (L.S.)