IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, OF CASTINGS OR ARTICLES THEREFROM AND IN FURNACES AND APPLIANCES THEREFOR, THE SAID FURNACES BEING ALSO APPLICABLE FOR OTHER PURPOSES "
Year: 1882

page_text: "
LETTERS PATENT to Thomas Lishman, of West Hartlepool, in the county of
Durham, but temporarily of Walsall, in the county of Stafford, Engineer
for an invention of IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL, OF CASTINGS OR ARTICLES THEREFROM AND IN FURNACES AND
APPLIANCES THEREFOR, THE SAID FURNACES BEING ALSO APPLICABLE FOR
OTHER PURPOSES
"
PROVISIONAL SPECIFICATION left by the said Thomas Lishman at the
Office of the Commissioners of Patents on the 3rd May 1882.
THOMAS LISHMAN of West Hartlepool in the county of Durham but temporarily
of Walsall in the county of Stafford, Engineer "IMPROVEMENTS IN THE MANU-
FACTURE OF IRON AND STEEL, OF CASTINGS OR ARTICLES THEREFROM AND IN
FURNACES AND APPLIANCES THEREFOR, THE SAID FURNACES BEING ALSO APPLICABLE
FOR OTHER PURPOSES
"
This invention relates to improvements in apparatus and furnaces chiefly
applicable to the manufacture of steel and iron the improvements in the said
furnaces being also applicable to general heating purposes, the invention also
relates to methods and appliances for the manufacture of cast and homogeneous
steel and malleable irou from ordinary pig, raw or crude iron by dispensing with
the puddling process and to the production of castings or articles therefrom.
In making steel according to my improvements I reduce the pig iron, ore or
mine in a furnace constructed as hereinafter described to a liquid state and then
transfer it to a suitably arranged converting furnace, when according to the con-
stituent elements of the liquid iron, portions of which are to be eliminated I infuse
therein or add thereto suitable proportions of one or more of the following
ingredients, videlicet
Prepared lime, calcined bone, raw bone, salt, soda, manganese, flour-spar (fluoride
of calcium), scrap iron and ground anthracite.
The converting furnace is provided with a steam pedestal suitably placed and so
arranged that it can be raised from or lowered into the liquid metal.
The pedestal is perforated with a number of holes through which steam is ejected

page_text: The chemical action thereby produced aided by the intense heat purifies the crude
iron and afterwards converts it into steel, which may be run into ingots or slabs of
the size or shape required and then be rolled into bars, sheets or plates. The
proportions of the hereinbefore described ingredients or mixture of ingredients and
the length of time of the steam blow are regulated according to the composition
of the iron and the quality of steel required.
For producing malleable iron the crude metal is treated in a manner similar to
that herein before described and when purified the metal is run into moulds of the
required size, or the metal may be allowed to thicken in the furnace, then be
balled up and manipulated in the ordinary way.
The improvements are also applicable to the production of steel or malleable iron,
castings either for bars or sheets and particularly when intended to be used in the
manufacture of Plate mill rolls. In manufacturing such rolls they are cast with a
suitable number of orifices running lengthwise through them to admit of a proper
circulation of air to the internal parts of the metal by which means unequal
expansion and contraction are obviated and a true roll thereby secured. The
furnaces I employ when constructed for the purposes herein stated and for heating
purposes generally are built of brick work preferably within a wrought or cast iron
casing or shell.
The receptacles for the fuel may be shaped in any ordinary way
in the form of a basket. with open sides and end and securely encased by an
arrangement of doors; combustion is effected by the fuel being supplied with hot
air conveyed to the gas chamber, also under the grates, by means of air channels
traversing the entire surface of the furnace and carried to a receiver at the back of
the chamber, the gases meeting therein as well as the hot air, are conveyed to the
furnace by means of orifices suitably arranged for the purpose. The escaping
gases after passing over the floor of the furnace are returned along a conduit or
Hue in connection with which are air cells communicating with it by orifices and
the gases are re-used for heating purposes and for perfecting the combustion. The
surplus gases may then be conveyed to an underground flue, thence to a chimney
or stack, or be carried to the flue of a boiler and further utilised for generating
steam.
Steam jets are also applied underneath the floor of the furnace and grate bars
above the ash pit. The bridges are formed hollow, into which steam and hot air
are admitted which pass from thence through orifices to the furnace, intermixing
with the gases escaping from the accumulator and fire chamber, thereby perfecting
the combustion and increasing the heat; the whole is regulated by valves or doors
in such a way that only the required quantity of gas and air is admitted to either
increase or diminish the heat as required. The fuel is supplied to the fire chamber
by means of an appliance attached to a hopper above or on top of the chamber, the
fuel is thereby broken into regular sized pieces and equally distributed for the
supply of the necessary gas.
The furnaces may be lined with ganister or other materials for resisting heat,
but by preference for the better production of the metals, charred bone, ground
anthracite or black lead, ground brunt, fire brick, calcined manganese, silicate of
alumina, red hematite and ground calcined forge cinder and lime are employed
properly mixed, and either made into bricks or stiff paste and put in in the
ordinary way.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Lishman in the Great Seal Patent Office on the
3rd November 1882.
THOMAS LISHMAN of West Hartlepool in the county of Durham but temporarily
of Walsall in the county of Stafford, Engineer "IMPROVEMENTS IN THE MANU-
FACTURE OF IRON AND STEEL OF CASTINGS OR ARTICLES THEREFROM, AND IN
FURNACES AND APPLIANCES THEREFOR, THE SAID FURNACES BEING ALSO APPLICABLE
FOR OTHER PURPOSES
"
This invention relates to improvements in apparatus and furnaces chiefly
applicable to the manufacture of steel and iron, the improvements in the said
furnaces being also applicable to general heating purposes, the invention also
relates to methods and appliances for the manufacture of cast and homogeneous
steel and malleable iron from ordinary pig, raw or crude iron by dispensing with
the puddling process and to the production of castings, forgings, or articles
therefrom.
In making steel according to my improvements I reduce the pig iron, ore or
mine in a furnace constructed as hereinafter described to a liquid state and then
by preference transfer it to a suitably arranged converting furnace but the iron,
ore or mine may be reduced and dealt with in the converting furnace only when
according to the constituent elements of the liquid iron, portions of which are to
be eliminated I infuse therein or add thereto suitable proportions of one or more
of the following ingredients, videlicet.-Prepared lime, calcined bone, raw bone,
salt, soda, manganese, flour-spar (fluoride of calcium) ground anthracite, nitrate of
soda, iodide of potassium, soda of potassa and scrap steel and iron.
The converting furnace is provided with a pedestal suitably placed and so
arranged that it can be, if required raised from or lowered into the liquid metal.
The pedestals are perforated with a number of holes (one hole may be sufficient)
through which a blast of air by preference or steam is ejected; the chemical action
thereby produced aided by the intense heat purifies the crude iron, and afterwards
converts it into steel, which may be run into ingots or slabs of the size or shape
required, and then be rolled into bars, sheets, or plates. The proportions of the
hereinbefore described ingredients, or mixture of ingredients, and also the length
of time of the air, or steam blow, are and must be regulated according to the
composition of the iron used in the converting furnace and the quality of steel
required.
For producing malleable iron, the crude metal is treated in a manner similar to
that herein before described, and when purified the metal is run into moulds of the
required size, or the metal may be allowed to thicken in the furnace then be balled
up and manipulated in the ordinary way. The improvements are also applicable
to the production of steel or malleable iron castings and for rolls for the manufacture
of plates, sheets or bars; in manufacturing such rolls they are cast with orifices
running lengthwise through them, as by preference with a worm cast in of sufficient
area to admit of a proper circulation of air to the internal parts of the metal by
which means unequal expansion and contraction are obviated and a true roll
thereby secured.
The furnaces I employ, when constructed for the purposes herein stated and for
heating purposes generally are built principally of brickwork preferably within a
wrought or cast iron casing or shell.
The receptacles for the fuel (excepting those arranged for steam boiler purposes)
may be shaped in any ordinary way but by preference in the form of a basket
with open sides and end, or by an arrangement of grates, fully hereinafter described,

page_text: 1
and securely encased by arrangement of doors. Combustion is effected by the fuel
being supplied with hot air and steam, conveyed to the gas chamber, also under
the grates by means of air channels traversing the entire surface of the furnace,
and conveyed to receivers arranged at the sides and back end of the chamber, the
gases meeting therein, as well as the hot air are conveyed to the furnace by means
of orifices suitably arranged for the purpose. The escaping gases after passing over
the floor of the furnace may be returned along a conduit or flue in connection with
which are air cells communicating with it by orifices and the gases are reused for
heating purposes and for perfecting combustion.
The surplus gases may then be conveyed to a chimney or to an underground
flue, thence to a chimney or stack, or be carried to the flue of a boiler and further
utilized for generating steam. Steam jets are also applied underneath the floor of
the furnaces and grate bars above the ash pit. The bridges are formed hollow into
which steam and hot air are admitted which pass from thence through orifices to
the furnace intermixing with the gases escaping from the accumulator and fire
chamber thereby perfecting the combustion and increasing the heat. The whole
can be regulated by valves or doors in such a manner that only the required
quantity of gases and air is admitted to either increase or diminish the heat as
required.
The fuel may be supplied to the fire chamber in the ordinary way, but by
preference by means of an appliance to which there is attached a hopper or
receptacle for the fuel the whole is placed above or on the top of the chamber, by
its application the fuel is broken into regular sized pieces dried and equally
distributed for the supply of the necessary gas.
The furnaces may be lined with ganister or other material for resisting heat, but
by preference for the better production of the metals, ground anthracite, black-
lead, ground burnt fire brick, common brick or clay, lime, manganese, silicate of
alumina, hematite, and ground forge cinder, or scale, are employed properly mixed
and either made into bricks or stiff paste and put in in the ordinary way.
The furnaces may be of any suitable size and shape and be constructed of any
suitable materials such as are generally used for such purposes but in the manner
hereinafter described for the purpose of heating the air fed to the furnace and
preserving the materials.
In order to enable my Invention to be better understood I will proceed to
describe the same by reference to the accompanying drawings the several figures
of which represent various forms of furnaces constructed according to my
improvements. Similar letters in all the figures represent similar or corresponding
parts.
In sheet 1, figure 1, represents a longitudinal section taken through the line A, A,
of figure 3. Figure 2, a vertical section on the line B, B, of figure 1, and figure 3,
is a horizontal section on the line C, C, of figure 1, shewing a part of my improve-
ments applied to a double furnace; a, is the wrought or cast iron casing or shell
of the furnace; b, is the fire chamber which may be formed as shewn and the fuel
therein is supplied with heated air, obtained by means of the channels c, shewn
also in dotted lines at figure 3, formed along the bottom of the furnace and com-
municating with the fire bridge d, from thence the air passes through the orifices e,
to the under side of the grates and through the orifices f, into the chamber h, and
through the orifices y, formed in the cast iron bearing plate m, into the chamber h',
whence the hot air is admitted to the fire chamber through the orifices i, i, formed
in the brick-work, (or cast iron may be used for this purpose) I may also use a
jet of steam as shewn at j, which is a steam pipe for forcing the required quantity
of air to the under side of the grates; a portion of the said air and steam is
admitted to the bridge d, which is formed hollow as shewn; at the centre of the
bridge d, is a hollow pillar k, in which are orifices l, for the emission of the steam
and air admitted; this pillar, extends to the roof of the furnace and acts as a
support thereto. From this construction of furnace it will be understood that hot
air is supplied to the fuel in the grate b, by means of the air channels and the
-

page_text: t
chambers h, and h', which are in communication with the fire chamber, the air
thus becomes heated while passing through the said air channels or flues to the
air chambers, and the heat generated by the fire is thereby intensified, the gases
thus meeting with and increasing the intensity of the flame and consuming the
smoke. The products of combustion after passing over the floor n, of the furnace
may be utilized by being conveyed to the flues of a boiler o, or be conducted to
the chimney or stack; p, is the charging door shewn also in detached elevation
and section at figures 4 and 5, and q, is the rubble hole therein it is provided with
an opening or flue r, communicating at its top either with a flue inside the shell
or casing a, and so with the chimney or stack or to a funnel s, as shewn, the object
of this construction of charging door is to prevent cold air entering the furnace at
the rubble hole q, as is ordinarily the case and thus obviate the injurious effects
thereby produced, the cold air being thus prevented from acting upon the molten
iron, as such air will be carried away with the heated gases through the said flues 7,
and 8, and be used for heating purposes.
may
Figure 6, sheet 1, is a longitudinal section on the line D, D, of figure 8, of a
small or single furnace for heating or puddling purposes constructed according to
my improvements; figure 7, sheet 1, an end elevation of the same and figure 8
sheet 1, a horizontal section of the same on the line E, E, of figure 6.
In this arrangement the grate bars b, which are hollow are in communication
with the bridge d, which is divided into compartments u, u¹, and v, v₁, and is
formed of cast iron and may be cast in one piece but by preference in separate
parts as shown and protected externally by brickwork. The top of the com-
partment v, of the bridge is formed with a number of orifices above which are
placed specially constructed bricks provided with orifices l, which are vertical for
a certain distance and thence extend horizontally to the front of the bridge, the
said orifices, forming a continuation of those formed in the top of the
compartment v.
Air enters at the outer end of the fire bars b, and passes in the direction shewn
by the arrow in figure 6 into the compartment v, of the bridge d, and the heated
air and gases escape through the orifices l, and intermix with the escaping gases
from the fuel chamber b, whereby the flame and heat are considerably intensified
or increased.
c, c, are the air supply channels formed by preference of cast iron
pipes but they may be formed of brickwork; they extend to the outer end of the
furnace; the air enters at the ends t, in the direction shewn by the arrow in
figure 6, the other ends being fixed to and entering the bridge d; the said pipes c, c,
are carried along the bed or floor n, of the furnace, and form the bottom thereof.
The currents of air pass from the ends t, through the pipes and meet in their
respective compartments u, and u¹, of the bridge d, and pass out at each end of
the bridge as indicated by the arrows, the bridge being provided with a partition
plate W, in the centre. The air having thus become greatly heated is admitted to
the air cells x, on each side of the fire chamber b, where it is still further heated;
orifices y, y, are formed in the sides of the fire chamber b, which is lined with a
wrought or cast iron plate z, z, the said orifices extend over the full area of each
side of the fire chamber and grate surface; each of the said cells x, x, communicates
with the chamber h', and at the firing end of the furnace as well as with the ash
pit; communication between the chamber h³, and the fire chamber is effected by
means of the orifices i, i, formed in the brick work or in a cast iron grate or plate,
through which the hot air passes to the fire chamber b, air may also be conveyed
over the top of the furnace in a similar manner to that hereinafter described to the
chamber Steam may also be employed by placing a supply of water in each of
the pipes c, or b, by which means additional heat is obtained. All the necessary
elements for effecting a perfect combustion thus meet in the gas chamber and
produce in the furnace the greatest possible heat with a minimum consumption of
fuel. At the end of the pipes c, figure 8, a box or case a¹, may be attached having
one or two blast pipes b', b', fixed as shewn or in any other suitable way or
position the air being obtained by means of a fan, driven by an engine or otherwise

page_text: by which means the quantity and regularity of the supply of air would be under
the control of the attendant whilst heats could be obtained in much less time than
is ordinarily the case. c', is a cast iron bearing plate forming the bottom of the
chamber h d', is a wormed shaft attached to the end of the furnace in a suitable
position and gearing with the pinion wheels e¹, secured to the end of each fire bar b,
and driven either by hand as shewn or by other suitable mechanical appliance,
whereby the grate bars b, may be caused to rotate and by this means the ash would
be effectually thrown out and clinker greatly diminished or prevented. Rotary
movement may be communicated to the fire bars by means of a ratchet motion
instead of by a wormed shaft as described the ash pit as well as the other end of
the furnace are closed by means of doors (not shewn in the drawings) thus air is
excluded from all other parts and is only supplied through the channels or flues
and by such means as have been hereinbefore described. Fuel may be supplied to
the fire in the ordinary way through a fire door but by preference by Deans of a
hopper and apparatus on the top of the fire chamber as will be hereinafter described.
The arrangement of fire bars and construction of fire bridge last hereinbefore
described are very suitable for steam boiler purposes.
A
Figure 11, sheet 1, is a longitudinal section on the line F, F, of figure 14, shewing
a furnace for converting purposes constructed according to my improvements;
figures 12, and 13, sheet 1 vertical sections of the same on the lines G, G, and H, H,
respectively of figure 11, and figure 14, sheet 1, is a horizontal section on the line
I, I, of figure 11; figure 15, sheet 1, is a longitudinal section on the line J, J, of
figure 14. The fire grate b, and the method of supplying hot air thereto are
similar to those already described but in this construction of furnace the escaping
gases after passing over the floor n, of the furnace are conveyed downwards in the
direction indicated by the arrows; c, is the flue over which is the air channel x.
connection between the fue c, and the channel x, is formed by means of the
orifices g'. The said flue and channel extend from the front end around one side
of the furnace, back to the other end as shewn in figure 14. The current is aided
by a blast at the front end of the furnace. The escaping gases pass from the floor
n, of the furnace and are thus intermixed; they pass into the channel x, above and
heat the air admitted therein and thence pass onto the floor n, of the furnace and
into the fire chamber b, through the orifices y, y, the number and size of which are
varied according to the size and requirements of the furnace. A portion of the
heated air and gases also enters the fire chamber through the orifices i, i, from the
chamber ', in a similar manner to that described when referring to figures 1, 2,
and 3 and figures 6, 7 and 8, the remaining products of combustion passing off
through the flue o; by this means the escaping gases to a considerable extent are
reused, in the production of gas and in assisting combustion. For the purpose of
assisting in effecting the conversion of crude iron into steel as hereinbefore described
a blast or steam pipe is inserted on each side of the furnace where shewn in dotted
lines at ,, figure 14, or a piston is inserted either at top or bottom into the
metal, the blow at the required pressure is then applied aided by the required
mixtures, and by this means phosphorus and other impurities are expelled; on the
metal being ready or prepared it is run off into a ladle at the tapping hole and then
made into ingots or slabs to be afterwards rolled into bars or plates or otherwise;
or the metal may be prepared and run into castings of steel. The firing of all the
furnaces herein before described may be effected in the ordinary way but by
preference by an arrangement such as that shewn in figure 11 the fuel being placed
in a hopper j', at the bottom of which is arranged a fluted shaft turned by a wheel
and which crushes the fuel into regular sized pieces and better distributes the
supply.
Figure 16, sheet 2, is a longitudinal section on the line K, K, of figure 17,
shewing a furnace for steel ingot heating, mill or forge purposes or for steel making
and heating heavy masses of iron constructed according to my invention; figure 17,
sheet 2, is a horizontal section of the same on line L, L, of figure 16; figure 18,
sheet 2, is a longitudinal section on line M, M, of figure 17; figures 19 and 20,

page_text: sheet 2, vertical sections on the lines N, N, and O, O, respectively of figure 16
This form of furnace may also by making the floor of the furnace level with the
ground floor, be adapted for annealing purposes. The method of heating and
perfecting combustion in this furnace is similar to that herein before described, but
the furnace is furnished with a double fire grate b, b, with a partition wall kl,
between the fire chambers extending the length of the chambers to the bridge d.
This furnace is constructed to admit of its being worked from either or both sides
and also from the front end, p, being the charging doors arranged as may be
required; air cells c, are arranged to run along immediately below the bed or floor
of the furnace as shewn at figures 16 and 20; these cells may be constructed of
brick work or of cast iron pipes as herein-before described and serve to convey
heated air to the bridge d, which is constructed as before described when referring
to figures 1, 2, and 3 air is, or may also be admitted below the bed or floor through
the channels, and passing through the orifices m', in the bridge to the underside
of the perforated cast iron plate n', at the ash pit, the air passing through the
openings therein to the grate bars and through the orifices ff to the top p', of the
furnace where it meets the heated air from the channel o¹, at the top or crown of
the furnace and from thence to the air cells q', on each side; it then enters through
the orifices or grating r, to the fuel chamber b; a steam jet (not shown in the
drawing) may be used in combination as before described. The air currents are
induced by the draft obtained by the aid of the stack, but they may be increased by
the aid of a steam jet or fan blast, as before described; by preference this furnace is
furnished with an independent chimney or stack o, but the surplus and escaping
gases may be further utilized by being conveyed to a boiler in any suitable manner
such as by an underground flue for generating steam. The fuel chambers b, may
be provided with grates of any ordinary construction but by preference I employ
that construction shewn in the drawing. s¹, firing doors; t', is a slag bogie;
u, door of the chamber under the floor of the furnace in which the slag bogie
runs. The air channels c, c, are provided with doors v¹, for regulating the supply
of air; w¹, w', doors to the air cells q¹, the whole furnace is securely enclosed air
only being admitted where described and indicated. The covering of the channel o¹,
at the top of the furnace is by preference inade of light cast iron plates afterwards
well covered with sand or other suitable non-conducting materials, but a brick
cover may be used.
Figure 21, sheet 2, shews a longitudinal elevation of a plate roll constructed
according to my invention, figure 22, sheet 2, is an end view of the same and
figure 23, sheet 2, is a view of the coupling box. This improved plate roll is
furnished with an orifice through the centre and circulating the mass of metal in
the form of a worm screw 80 arranged that each intervening sectional part thereof
shall form a solid disc the air having full circulation through and around the
internal parts of the roll by which means the unequal expansion and contraction of
the roll is obviated and the risk of the breakages so generally occurring
considerably diminished. Figure 24, sheet 2, shews an end view of a similarly
constructed roll but with the orifices running straight through.
Figure 25, sheet 2, represents an arrangement of the fire grate bars which I
sometimes prefer to employ in constructing my improved furnaces. The bars b,
one of which is shewn in end elevation at figure 26, are formed hollow and circular
in shape with projections x', on each side as shewn. y, y', are the ends of the fire
grate forming the bearings of the said bars to which ends y', are fixed the two side
plates z, z, the whole forming a frame which is built into the brickwork of the
furnace; the ends of the bars may be square in section as shewn at a², a², to which
ends when the bars are required to be turned by hand, a spanner may be applied
and the projections x', be thus turned up or over by which the fuel is agitated and
means are thereby afforded for clearing and extracting clinker without drawing the
bais out of their place; only two wings or projections a¹, are shewn in the drawing
but it will be understood that three or four projections may be employed, such
being preferred in cases where the bars are required to be kept constantly

page_text: revolving. The length of the projections may be increased or diminished to suit
the quality of the fuel to be used. The bars b, may also be made solid and flat in
section with the projections as shewn in the drawing or modified to suit the
requirements of the fuel and the size of the furnace.
Figure 27, sheet 2, represents a longitudinal section on line P, P, of figure 28, of a
furnace constructed according to my improvements and provided with a fire grate
the bottom of which is formed of perforated plates; figure 28, sheet 2, is a
horizontal section of the same on line Q, Q, of figure 27, and figure 29, sheet 2, is
a vertical section on line R, R, of figure 27. Instead of employing perforated plates
I may sometimes employ bars placed close together, the sides z¹, of the fire grate
being arranged in the form of a basket as shewn in figure 29. The sides 21 of the
grates may consist of ordinary iron bars or of perforated cast iron or bricks
suitably arranged and built into the brick work of the chamber b.
Figure 30, sheet 2 is a longitudinal section on line S, S, of figure 31, and
figure 31, sheet 2, is a horizontal section on line T, T, of figure 30 shewing a
furnace constructed in a similar manner to that described when referring to
figures 6, 7 and 8 sheet 1 with the exception that the air is admitted at the end 6³,
of the top or crown o', of the furnace through which the air travels to a box or
case c², and from thence down through the pipes d², into the box e², attached to the
ends of pipes c, and from thence along the pipes or channels c, to the fuel as
herein before described. A jet of steam by preference is applied to the outer end
of the pipes c, for the purpose of increasing the current of air and preserving the
furnace bottom.
In some cases I prefer to construct the pipes or channels c, in the manner shewn
in figure 32, sheet 2, the object of this arrangement being to avoid the necessity of
employing plates underneath them, and in case of one or more of the pipes becoming
burnt through to allow of removing the same and of replacing them without
it being necessary to take down the furnace. This construction will be readily
understood by reference to the drawing without further description.
By the improvements bereinbefore described, an almost perfect combustion is
obtained, a great saving is effected in fuel, a regular and continuous heat is kept
up, the smoke is effectually consumed, and the greatest possible amount of heat is
obtained from the fuel the construction of the furnaces is also, very simple and in
the case of puddling furnaces the quality and yield of iron are much improved.
Having thus described the nature of the said invention I wish it to be
understood that what I claim is :-
Firstly. The method herein described of producing or manufacturing steel and
iron or castings or articles therefrom.
Secondly. The general arrangement and construction of furnaces as herein before
described and represented in the accompanying drawings.
Thirdly. The method herein described of heating the air for supplying furnaces
by the employment of pipes and hollow bottoms to the furnaces as herein before
described and represented in the accompanying drawings.
Fourthly. The employment for furnaces of all descriptions of fire grates, bars, and
bridges, constructed as herein before described and represented in the accompanying
drawings.
Fifthly. The method herein described of effecting combustion by causing the
unconsumed gases and air to be returned to the fire grate by the arrangement of
return flues as herein before described and represented in the accompanying
drawings.
Sixthly. The herein described method of making steel and iron without puddling
as herein before described.
Seventhly. The manufacture of rolls, with orifices and internal discs for the
prevention of breakage as hereinbefore described.

page_text: Eighthly. The employment for steam boiler purposes of the arrangement of fire
bars and bridges herein before described and represented in figures 6, 7, and 8
sheet 1 of the accompanying drawings.
In witness whereof I the said Thomas Lishman have hereto set my hand
and seal this thirty first day of October in the year of our Lord one
thousand eight hundred and eighty two.
THOMAS LISHMAN (L.S.)