AN IMPROVED SYSTEM OF WORKING METALLIC ORES AND THEIR PRODUCTS, BOTH METALLIC AND MINERAL
Year: 1857

page_text: LETTERS PATENT to John Talbot Pitman, of the American and European
Patent Offices, 67, Gracechurch Street, London, for the Invention
of "AN IMPROVED SYSTEM OF WORKING METALLIC ORES AND THEIR PRODUCTS,
BOTH METALLIC AND MINERAL."-A communication from a citizen of
the United States of America.
Sealed the 11th August 1857, and dated the 11th February 1857.
PROVISIONAL SPECIFICATION left by the said John Talbot Pitman at:
the Office of the Commissioners of Patents, with his Petition, on
the 11th February 1857.
I, JOHN TALBOT PITMAN, of the American and European Patent
Offices, 67, Gracechurch Street, London, do hereby declare the nature
of the said Invention for "AN IMPROVED SYSTEM OF WORKING METALLIC ORES
AND THEIR PRODUCTS, BOTH METALLIC AND MINERAL," a communication from a
citizen of the United States of America, to be as follows:-
This Invention consists of a series of novel constructions and pro-
cesses whereby I improve the quantity and quality of the metallic and
mineral products obtained by smelting ores and subsequently treating
their products. And, first, I construct two furnaces, called the alpha
and omega furnaces, in the former of which I commence, and in the
latter of which I finish my processes.
The alpha furnace consists of a crucible of any desired form and

page_text: diameter, either square, rectangular, conical, or cylindric, and vary-
ing in height from one to fifty feet. This crucible rests upon and opens
hearth used for the reception of the molten material.
into a
The
upper part of the crucible is prolonged into a sloping or horizontal
stack or chamber of any convenient diameter, and varying in length
from five to five hundred feet.
When built sloping, this stack has a double upper wall or casing, the
outer or exterior of which is a close covering, and the inner is per-
forated along its entire length. Between these walls a chamber is
formed, over the lower or ordinary floor chamber of the stack. When
built horizontally, which in most localities is preferable, the lower and
the upper floor, or inner wall or casing, are made moveable, each con-
sisting of an entire bed or plate, or sections of an entire plate, joined
end to end, continuously in an uninterrupted series, reaching through
the whole length of the stack, which are moved forwards, by suitable
machinery, from the upper to the lower end of the stack, whence they
are returned empty, either outside or within the stack, to the upper end.
Around the crucible, and also around the stack, whether inclined or
horizontal, I arrange, in smelting certain ores, numerous tuyeres for
admitting blast or hot or cold air, varying from two to twenty in number
around the crucible, and from two to fifty along the stack. I also con-
struct numerous holes in the outer side and outer top walls of the stack,
through which to manipulate upon the materials therein, and by means
of which I supply foreign material to the product contained in the
stack.
Between the sides of the traversing bed plates and the side walls of
the furnace make a close joint, in the manner subsequently described
in the construction of the omega furnace.
The alpha furnace is ordinarily heated by anthracite or bituminous
.coal, charcoal, coke, hot and cold blast, and any suitable fuel, although,
for the purposes of economy, I prefer to dispense with all additional
fuel after the blast has commenced to act, or the hearth of the furnace
has by any method been fired to a smelting heat; having ascertained
that a plentiful supply of air (hot or cold) to the hearth ensures
sufficient combustion without fuel, inasmuch as the ore itself is a com-
bustible product.
The omega furnace consists of an oven enclosed between two side
walls and an upper arch or roof, the said oven being of any desired
width, and varying from four to forty feet in height, and from ten to five
hundred feet in length.
Above the arch or roof, parallel therewith, I construct two or more
flues leading from the interior of the oven into the chimney shaft, which

page_text: latter rests upon and opens into the oven roof at any convenient point
between the middle and terminal end of the oven.
In the front end of this oven I construct a feeding hearth or refining
chamber or reservoir, consisting of a space enclosed between the two
side walls of the oven, and a sloping or level bed or floor made of brick
or other refractory material; said space being enclosed by an outer wall
at the front of the oven, and partly enclosed by a bridge at its inner
termination. This chamber varies in length from two to twenty feet,
and is intended to receive molten metallic and mineral products from
the alpha furnace. Flame and heat admitted into this refining chamber
pass over the terminal bridge into the body of the oven, and upon any
moveable moulds, plates, or material contained therein. This chamber
extends from the roof of the oven downwards only a limited depth,
leaving space underneath its floor for the passage of a second and
moveable hearth. This second under and moveable hearth consists of
a series of waggons or traversing bed plates, which, whether in rest or
motion, always extends through the whole length of the oven from end
to end. These bed plates are made from fire clay, metal, soapstone,
granite, or other refractory material, the sides of which move in niches
or grooves (horizontally made in either side of the walls of the oven);
said sides having flanges or dippers attached thereto, which dip into a
box, or tube, or gutter filled with sand or other suitable material; said
sand box or gutter being made of metal or burnt clay, being built along
the inner side of either wall of the oven (at any desired elevation to
correspond with the height of the dipper), along the entire or only a
part of the length of the oven, or if not built into the walls, the said
gutters or sand box rest upon the ground.
The traversing bed plates are moved forward continuously from the
front to the terminal end of the oven by a rack and pinion, or by a double
rack and pinion are moved backward and forward in regular succes-
sion, but in opposite directions, one rack advancing laden with castings,
the other returning empty. For occasional purposes I construct a
revolving cylinder to act as an overshot or undershot wheel within the
oven, and near the end or termination of the feeding hearth or floor.
The front and terminal ends of the oven are closed, excepting to allow
sufficient space for the ingress and egress of the waggons or traversing
bed plates.
. The omega furnace is heated by grates in front and at the sides, or
by hot air or blast introduced along the top, in which I burn coal, a
mixture of gas tar and water, or any desirable fuel.
In front of this furnace, and at various intervals within it, I arrange
various presses, rollers, stamps, springs, hoppers; the rollers having a

page_text: plain surface, or having various patterns raised or sunk on them. Some
of the rollers are compound, consisting of a central adjustable roller,
with an inclined press attached to or fixed near its base on either side,
the one being anterior, the other posterior to the roller in action:
Casting boxes, made to revolve partially or entirely, are also
suspended or arranged in front of and within the oven.
At times also, I construct and arrange conical and wedge-shaped
moulds to form the sides or inner cores of castings.
At times also, especially for hollow castings, I construct complex
jointed moulds, opening laterally, and with rims or bands fixed around
a central core, so as to be pressed upward or downward for the con-
venient withdrawal of a hollow casting from its position above a conical
or circular core.
By means of these moulds, rollers, springs, &c., I am enabled to cast,
press, roll, enamel, stamp, emboss, imprint, and otherwise work the
molten material after it is admitted from the alpha into the omega
furnace.
I sometimes, moreover, construct an additional oven for the recep-
tion of the material when molten and cast into shape, which consists
of a central pillar or column (of brick or stone), from which permanently
fixed shelves (of similar material) radiate horizontally at different
elevations over each other; the whole of which I enclose in a revolving
cylinder or oval case of metal, or other suitable material.
Openings are left in the case, through which the castings, while hot,
are inserted within the case and arranged upon the shelves, said shelves
having been previously heated.
Along the whole extent of the alpha and the omega furnaces I con-
struct holes, through which to watch and also manipulate upon the
material therein.
Within the omega furnace, and for the purpose of enamelling, I
sometimes construct a series of double rollers, one to revolve over
another, the lower of which dips into fluid slag. The sheet or strip of
metal or other substance to be enamelled is drawn from end to end of
the omega furnace between the under and upper sets of rollers, so as to
receive a coating of enamel from the under roller, while the upper roller
acts so as to fix and smooth the enamel. The rollers used in all the
above arrangements have a plain or indented surface, are either solid
or hollow, are used either hot or cold, are made of stone, iron, or-of
metal and mineral combined, or of clay, soapstone, sandstone, granite,
or other suitable material; and at times they are arranged so as to be
capable of elevation or depression, by which means, aided by the action
of the long traversing oasting bed plates, I am enabled to cast entire

page_text: columns, solid or hollow, of any desired length from one to five hundred
feet; also, to cast fluted or ornamental pillars or other architectural
ornaments of various forms. I sometimes build the omega furnace
below the level of the ground for the convenient reception of the molten
product from the alpha furnace.
Secondly, having thus described the constructions, I will now proceed
to explain the process involved in my improved system of heating ores
and their products.
Certain ores I take in their raw unwasted state, and placing them
within the end most distant from the crucible, gradually move them
along to the crucible and hearth of the alpha furnace. The heat and
flame ascending from the crucible (when ores are ignited therein)
gradually heats and oxidises the ores in their descent. Certain other
ores I
prepare for smelting by pulverizing them and pressing them into
the form of a perforated block. Other ores, after being pulverized,
I mix with flux, fuel, and a cementing wash, and then press them into
the form of a hollow or perforated block; these blocks I place upon
the traversing perforated arch, and also upon the lower hearth of the
alpha furnace stack, on which they are gradually carried to an increas-
ing temperature, and at length to the crucible, into which they fall.
In thus moving the ore from the coldest end of the stack, I am enabled
to roast and calcine it, and gradually add thereto salt, manganese,
mineral, earths, and oxides, other ores, and any ingredient that may
favorably act upon it, chemically or mechanically.
And since the ascending flame and heat plays upon and heats
simultaneously the ore upon the perforated casing, and also that upon
the floor proper of the furnace, the melting of a given quantity of
material is performed in half the usual time, and at half the usual
expenditure of fuel.
The molten product is then removed by suitable arrangement from
the alpha to the omega furnace, first passing by any suitable channel into
a refining chamber, which is enclosed by the feeding hearth. There it
is subjected to the action of heat, and is colored and also refined by
subsidization, and purified by the removal of its ścum and debris. And
inasmuch as the feeding hearth is usually inclined, the heavier particles
of metal and mineral sink to the bottom of the chamber.
The contents, therefore, of this chamber are withdrawn through
orifices arranged at different elevations above one another, and the
densist fluid falls from the lowest orifice. From the feeding hearth the
molten product runs down continuously or at intervals upon hot moulds
resting upon the top of the traversing casting bed plate, or upon the top
surface of the said plates without moulds, or upon sand moulds, or any

page_text: of the moulds for casting previously described. Said casting process
takes place either in front of or within the omega furnace.
The castings thus formed, whether open or shut, and whether left in
or removed from the mould, are then progressively moved forward from
end to end through the omega furnace, which, from its great length and
close construction, is admirably adapted for retaining the castings in a
molten or hot condition during such length of time as is required to
render them malleable or devitrified, or to allow of their being rolled,
stamped, cut, pressed, embossed, or otherwise chemically or mechani-
cally treated, and afterwards. gradually cooled before reaching the
terminal end of the oven.
At times the castings are imbedded while hot in hot sand, coal ashes,
pulverized mineral, oxides, &c., while being gradually cooled, and the
materials ordinarily used for making the moulds for casting in are metal,
sand, pressed dry fire clay, pressed shale, and mineral oxide, granite,
soapstone, &c.
The moulds are generally heated before use, although I sometimes
cast in cold moulds, in order to chill and vitrify the product.
In addition to the ordinary use of the rollers for pressing, I occasionally.
employ the following system of imprinting designs-I arrange several
rollers at regular intervals, extending laterally from wall to wall through
the oven.
Upon each roller is sunk or raised the several parts of any
design or pattern which are intended to be of the same colour. If
four colours, (viz',) yellow, blue, green, and red, are in the pattern, four
rollers are consecutively used, all of which, however, act upon the same
breadth of the pattern at different intervals. Thus, as the traversing
bed plate containing the molten or hot solid product, after having
entered the front end of the oven, passes under the first roller it receives
one or more indentations, according to the number of yellow figures in
the pattern. The bed plate passes next under a hopper, from which
yellow colored enamel or slag falls into and fills the depressions. This
breadth of the bed plate next passes under a spring or scraper, which
scrapes off all superfluous coloring material. The bed plate then passes
under a series of similar operations until all the colours are imprinted.
In pressing bottles and similar articlés: from: slag and analogous
mineral products, I use a double mould,' so contrived that after having
pressed a cylindrical tube with a close bottom, I raise the plunger, and,
by a mouthpiece or neck mould, afterwards compress the top of the
cylinder while hot into a neck or other shape.
In both the alpha and omega furnaces above described, I sometimes
form the inner surface of the arch with projections of fire brick or other

page_text: suitable material, so as by retarding the current of heat and flame to
produce bidynamic intensity of heat.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Talbot Pitman in the Great Seal Patent
Office on the 11th August 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TALBOT PITMAN, of the American and European Patent Offices, No. 67,
Gracechurch Street, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of February, in the year
of our Lord One thousand eight hundred and fifty-seven, in the
twentieth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Talbot Pitman, Her special
licence that I, the said John Talbot Pitman, my executors, admini-
strators, and assigns, or such others as I, the said John Talbot Pitman,
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
"AN IMPROVED SYSTEM OF WORKING METALLIC ORES AND THEIR PRODUCTS,
BOTH METALLIC AND MINERAL," a communication from a citizen of the
United States of America, upon the condition (amongst others) that I,
the said John Talbot Pitman, 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 John Talbot Pitman, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings:-

page_text: Figure 1 represents the alpha furnace (so called) with its cone or body sloping
upwards.
Figure 2 represents the alpha furnace (so called) with its cone or body hori
zontal.
Figure 3 represents the plan of said furnaces constructed in a circular or annu-
lar form.
Figure 4 represents the vertical section of the same, on the curved line B, B,
on Figure 3.
Figure 5 represents the vertical section of the same, on the line A, A, on
Figure 3.
Figure 6 represents a section of the plan in the circular form.
in line C, C, "
7
a
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33
plan of the omega furnace (so called).
8
"
9
"
"
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10
ditto
"
33
a vertical section of the same in line E, E, of Figure 7.
a cross section of the same, in line B B,
in line A, A,,,
23
33
"
"
- "
11
ditto
8.
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12
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ditto
33
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13
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ditto
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14
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ditto
Figure 8.
"
15
"
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16
"
17
"
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33
in line D, D, "
in line F, F,
through the chimney Hof
an oven, having revolving cylindric case with shelves.
a section of chamber w, with pattern moulds.
the back end; 18 the front end; and 19 the longitudinal
section of the casting and annealing waggons or bed plates.
Figure 20 represents the mode of operating the waggons or truck.
!
21
a double relief mould.
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"
22 represents a mode of shaping by rollers and presses.
33
23 represents a casting box, having sides to be withdrawn.
33
"
24 represents a central moveable core, formed of hemispherical plates.
The same mark indicates similar parts.
It has hitherto been customary to smelt iron and other metals in
furnaces and by processes adapted to obtain a satisfactory yield of
metal only; I have ascertained that the mineral products fused
ordinarily with said ores are of great commercial value, and therefore
construct furnaces, prepare ores and fluxes, and regulate the processes
of smelting, condensing or refining, casting and annealing, so as to
ensure greater value to the entire products of the ores smelted than is
ordinarily obtained.
And, first, in order to combine mechanical with chemical action in
the smelting process, I introduce the ore into the smelting furnace in
the form of perforated or hollow blocks, or their equivalent, said blocks
being made of unbroken or pulverized ore, of ore mixed with flux, or
of ore mixed with flux and fuel of any suitable character.
Secondly, I construct and use a compound furnace consisting of two
parts, one of which I call the alpha and the other the omega furnace.
The alpha furnace, in which my operations upon the prepared ores are

page_text: commenced, is constructed according to the forms shewn in Figures 1,
2, and 3, either of which I use, according to the local requirements or
circumstances. In either form the boshes or lower cone (c), Figure 1;
and the hearth H, are constructed after the usual method of blast
furnaces, but the upper portion (s), usually termed the cone or body of
the furnace, and which for brevity is called the body, is built either
horizontal, as shewn in Figures 2 and 3, or sloping upwards, as in
Figure 1, and made to enclose on chamber (S), Figures 2 and 3, or
two separate and parallel chambers one over the other (S, S',) Figure 1.
When two chambers are used, suitable openings (), Figure 1, are left
in the arch that separates them, through which the current of hot air
blast, heat, or flame can pass from the lower chamber into the upper,
whilst openings (w) are left in the side walls of both chambers, for con-
venience in manipulating upon the ores therein, and also to supply air
from without to the hot air within the chambers. The charge of ore is
introduced within the single chamber (S), Figures 2 and 3, upon a
moveable floor (D), upon which it is gradually moved to the belly of
the furnace (m), and thence to the hearth (H) through the boshes (C).
In like manner when the double chambers are used, as Figure 1, the
charge of ore is introduced within. the chambers (S, S',) through
openings in the top or sides thereof ('), near the throat (R) of the
furnace, but upon the fixed floors D, in which case the ore from the
upper chamber descends through the opening (P) into the lower
chamber, whence it passes, together with the ore of the lower chamber,
through the boshes (c) into the hearth (H). Whilst contained in the
boslies and hearth the ore is melted by blasts of hot or cold air, gas,
vapor, steam, or other suitable promoter of combustion applied directly
into and among the ore through the tuyeres (n), Figures 1, 2, and 3,
but while passing through the single body of the furnace S, Figures 2
and 3, or the double body S, S', Figure 1, the ore is roasted and heated
by the escape heat and flame ascending from the boshes, which is thus
caused to pass over the top surface of the descending ore without
injuriously affecting it, with the gaseous products driven out of the
ore resting in the boshes.
When the sloping body is used (Figure 1), the ore is caused to pass
from the throat to the belly thereof, either by gravitation or manipula-
tion;
but when the horizontal body is used (Figures 2 and 3), the ore 1
is moved from the throat to the belly thereof upon a moveable straight
or annular metal plate, covered or lined on top with fire brick or other
refractory material, with side flanges extending above and below the
same, said plate being actuated upon wheels, or by a double rack and
pinion, and constructed as shewn in Figures 17, 18, 19, and 20. At (m)

page_text: the ore is removed from the plate into the boshes (c), whilst the table
passes over a bridge (a), through the boshes, and thence through a
hole in the outer wall of the boshes to any point exterior to the furnace,
from which, by an exterior route, it is returned to the throat R, to be
re-admitted into the body (S). In the horizontal form of furnace a
boiler (0), Fig. 2, and hot air stoves P, are sometimes imbedded in
the roof of the body (S), so that the heat and flame as it passes through
S, is made to perform the double work of heating both the ore beneath
and the boiler and stove above it.
I find it convenient in certain localities to construct the horizontal
body of the alpha furnace circular or annular, as shewn in Figures 3, 4,
and 5, of which Figure 3 is an horizontal plan; Figure 4 a vertical
section thereof on the curved line B, B; and Figure 5 is a vertical
section on the line (A, A,) in which D represents an annular plate,
which is so constructed as to traverse continually an annular chamber S,
said chamber extending uninterruptedly through (or alongside of) the
base of the chimney E, and through the top of the cone (C) and the
arch (a). The arch is built over or across the cone (C), in the direction
of the curved line (B, B,) in such a manner as to form a partial roof
over the. cone (C). in order to protect the bottom or under side of the
plate D, whilst open spaces (f, f.) Figures 3 and 5, are left, on each
side of the arch, through which space the heat and flame pass upward
from the lower cone, over the top of the plate D, to the body (S), in
the direction of the arrows. The heat and flame thus ascending from
(c), through (f, f.) over the arch (a), passes along the body (S) over the
ore descending therein, and escapes at the chimney E. The body S
is elevated to a suitable height upon rising ground or upon arched
pillows J, with spaces K between them. Through the damper or
floor (g), when open, access is had to the interior of the chamber (S),
immediately over the cone (C), for convenience in removing the heated
ore from the plate D over the bridge formed by the arch (2), into the
cone (C) through the side spaces (f, f).
The plate D consists of one entire plate annular in form, or of sections
of plates closely joined, and overlapping each other, so as to form at all
times an uninterrupted moveable hearth or floor to the body (S). Its
top surface consists of fire brick or other refractory material, and its
general construction is the same as that described subsequently in con-
nection with the omega furnace. In the annular form of oven the ore
is thrown upon the empty plate D, through the hopper (w), at the
throat of the furnace R, and is carried along the body (S), through a
gradually increasing temperature, until it arrives at the belly (m), where

page_text: it becomes sufficiently hot to be removed into the boshes (c), leaving
the empty plate to pass again beneath the hopper. to be refilled.
After the molten products of the ore have reached the hearth H in
a fused state, they are withdrawn therefrom, either continually or at
intervals, into the omega part of the furnace, which consists of an open
or covered channel (e), Figures 4 and 5, leading directly into a long
annealing chamber (a), so as to allow the molten product to fall into
and be cast into moulds placed upon wagons or casting bed plates
moving through the chamber (u), or the channel (e) may lead into a con-
densing and refining chamber (a), built over the chamber (), in which
case the molten product first passes into the chaniber («), and after
being refined therein is withdrawn through suitable outlets upon the
wagons D, passing along the chamber (u), underneath the chamber (a).
The construction and modus operandi of the omega furnace are illus-
trated by Figure 7, representing a plan; Figure 8, a vertical section on
the line E, E; Figure 9, a cross section on the line B, B, of Figure 7;
Figure 10, a cross section on the line A, A, of Figure 7; Figure 11, a
cross section on the line C, C, of Figure 8; Figure 12, a cross section
on the line D, D, of Figure 8; Figure 13, a cross section on the line:F, F,
of Figure 8; and Figure 14, a section through the chimney H of Figure 8.
In Figure 8, (c) represents a covered channel, used for conveying the
molten product from the omega furnace into the condensing chamber
(a), which chamber is heated by the grates and fire-places B, Figure 9.
The hearth of the chamber () is usually built slopeing. A series of
waggons D move in endless succession through the chamber (u),
entering underneath the front end of the chamber (a), and leaving the
chamber (u) at any suitable point, after having passed through the
stack H. Suitable moulds, made either of metal, fire clay, soap-stone,
sand, or other material, are placed upon the wagons, which, together
with the wagons, are heated previously to entering into the chamber ("),
or underneath the chamber (a), from which they receive the molten
product. The chamber (2) is heated from the fire-places (c'), Figures 7,
10; but, if desired, the heat escaping from the chamber (a) may be
withdrawn over the bridge (d) by suitable flues into the chamber (u),
entering said-chamber at any desired distance, either before or after
the fire-places (c). The chamber (u) is always full of wagons, which
are closely joined together by overlapping plates, so that but little
heat can escape from the upper to the lower side of the wagons, and
both the front and rear end of the chamber (), are closed, except
to allow sufficient space for the entrance and removal of the wagons.
In the process of moulding or casting, the molten product, both
metallic and mineral are separately cast or poured from the chamber (a)

page_text: into heated moulds placed upon the wagon's, D², top. The moulds
are then withdrawn as soon as the casting has set, and the castings
carried through the annealing chamber (u), in which they are gradually
cooled for a longer or shorter time, and under a greater or less tempera-
ture, according to circumstances. At times the product is imbedded
in a casing of metallic or mineral oxide while hot, or is cast therein
and allowed to anneal in contact. therewith, in order to produce
chemical changes on the annealed product.
The flame and heat is admitted into the chamber () at such an
elevation as to pass freely above the wagons or casting bed plates which
form the moveable though entire hearth of the chamber (u), but the
flame is not allowed to pass underneath the wagons.
The temperature of the chamber (u) is regulated as follows:- The
flame and heat enter from the fire-places B, Figure 9, into the chamber
(a), and thence pass on to the arch (d'), Figure 8, into a flue of any
desired length, leading into the chamber (), whilst heat and flame
are also supplied to the chamber (u) from the side fire-places (c'),
Figures 7, 10. Thus introduced, the flame and heat pass onwards
towards the chimney H, Figure 2, in the direction of the arrows,
until arriving at the point (2), where they. are divided by the inner
arch (mm) into two currents, one of which continues through the
chamber (), whilst the other passes through the flue (f). into the
chimney H through the flue (). The chimney H also receives the cold
air from the opposite or rear end of the oven (u), which at () is also
divided into two currents, one of which passes towards (r), while the
other passes through the flue ("), over the arch (m) into the chimney H,
through the apartment ("). The partition (y), which divides the base
of the chimney for any convenient height or distance into the partitions
(and), rests upon the arch (m³, m³,). By closing the damper (g')
and opening the damper (g), the hot air ceases to pass through. the
flue (f), and is continued onward over the wagons in the chamber (u)
until it reaches the point (r), whence, together with the cold air
from the end of the oven, it passes into the chimney, H through ("
and )
By closing the damper (g) and opening the damper (g),
the cold air passes through the chamber (u) to (2), where it meets the
hot air, and passes with it through (2) into the chimney.
The chamber () terminates in a warm packing room or stove house
(A'), Figures 7 and 8, in which a crab winch L is stationed, by which
the wagons or plates (D2) are pulled through the chamber (7) upon
an inclined rail or other road, and in which chamber the products are
removed from the wagons, which are shifted by a return truck (J),
Figure 7, upon a return road (j), usually inclined, on which said wagons

page_text: arc returned to the front end of the oven () to be refilled, &c.
Within
the chamber (A!), or near, thereto, an oven is located, constructed as
shewn in (Figure 15), which consists of a revolving cylindric case (R'),
enclosing a hollow brick column (B), from which radiate numerous
horizontal shelves (d, d,) placed one over another at different heights,
into which oven I introduce certain castings through the openings or
doors (a, a,) placing them upon the shelves, taking care previously to
heat the oven by flame or heat, introduced from an exterior fire-
place by means of the flue (. ) into the interior of the column (B"),
and thence through the openings (c, c,) into the interior of the area
of the oven.
It is to be observed that the casing R' has a rack (e, e,)
turned by a suitable gear.
The hearth of the condensing chamber (a) I usually incline as shewn
in Figure 8, in which case the molten product is cast therefrom upon
the wagon top or plate, outside of the chamber (u), and just as the
wagons are entering within said chamber; but at times I prefer to
incline the hearth. in an opposite direction, as shewn in Figure 25,
constructing the omega furnace so as to leave a side opening (w) under
an arch (), said arch being formed to carry the heat and flame from
(a) over the bridge (d') into the chamber (). Through the side
opening (w) access can be had to moulten product, which in this case
runs from the chamber (a) through the opening (b, b.) upon the wagon
or casting place (D³).
The construction of the wagons or bed plates, and the mode of
actuating or making the same, as shewn in Figures 17, 18, 19, and 20,
in which Figure 19 represents a longitudinal section of these wagons,
shewing the mode of connection by means of draw bars (D", 1, 2, and 3),
said bars being successfully attached, as at (y), to form a continuous
train, and each bar being attached to the wagon after said wagon has
been loaded with castings, and pushed into the oven (), by means of
the pin (A) and guide piece (B). Figure 17 represents a cross section
of the back end of each wagon as it passes through the chamber (u);
in which (N) represents a recess in the side walls of the chamber (u);
(n) represents an angular brick sand box, which forms the base of said
recess on either side of the oven walls. Into this sand box, when
filled with sand, the side flanges (g) of the casting bed plate (D³) dips,
forming a close joint which confines the hot air of the chamber ()
to the space above the plate (D). A fire brick or refractory lining (¹)
covers said plate (D2). The wheels (O) of the wagon move on the rails
(v), which are fixed by the sleeper (s), which are built in the wall m.
(P) represents a press or roller, suspended over the casting bed plate
(D) under the arch (2) of the chamber (), which is occasionally used

page_text: to press the casting made upon the plate (D). Figure 18 represents
the front end of the wagon, shewing the guide bar (B'), between the
arms of which the drawing bar is supported while attached to the
wagon at the front end by the pin or bar A, Figure 17, In Figure 19,
(t) represents the front end of the plate (DD), so constructed as to over-
lap the rear end of the plate or wagon top preceding it, in order to
.make a close joint.
Instead, however, of constructing the bed plate as a wagon and
moving it by wheels upon a railroad, I find it desirable frequently to
adopt the mode of constructing and actuating steam shewn in Figure 20,
in which the casting bed plate consists of a series of metallic plates
(resting upon friction rollers (*), fastened in suitable brackets or hori-
zontal standards), and actuated by means of a double or compound
rack and pinion arrangement, as follows:-The rack (/) is attached
permanently along the under side of all the plates (D), in such a
manner that said plates in an endless continuation are moved forward
through the chamber (u), by means of a stationary pinion (e') fixed on
the shaft of the wheel (), which is actuated by the pinion (c) fixed
on the shaft of the wheel (6), moved by the pinion (a), to which the
. crank (y) is attached. Power and regularity in propelling the laden
tables D are thus gained, whilst by means of an additional series of
wheels and pinion (g', ',) a rapid motion is given to the empty plates
returning over or alongside of the top of the oven (u) from the rear to
the front end of the oven (u).
In pressing the molten material after it has been cast upon the plate
D, I sometimes employ, instead of the press P, Figure 17, a compound
roller placed within the chamber (), and constructed as shown in
Figure 22, and consisting of a roller (), made of metal, or stone, or
other suitable material, adjusted between an anterior inclined press
(m) and a posterior inclined press ("), in such a manner that as the
molten material enters the chamber () in the direction of the arrows
the plate D, it is gradually pressed under the anterior press, then under
the roller, and finally under the posterior press.
Sometimes two hemispherical plates are adjusted, as shewn in
Figure 24, between which, as a central moveable core arranged as (a)
and the end walls () of the niould or oven, I pour the moulten product
into a cylindric form B³, after which the central core is removed.
When I wish to make long castings, such as entire columns of the
moulten mineral product, as entire.bottoms for ships of the moulten
metallic product, or other long and wide castings, I use casting plates
or wagons of corresponding length and width, the chamber () of any
desired length, videlicit, from 10 to 10,000 yards, and of any desired

page_text: width, say, from 1 to 60 yards, using adjustable moveable presses
within the chamber () for regulating the form, size, or pattern of the
casting while in a plastic or semifluid state. I find it necessary also,.
in making certain kinds of, castings of the above moulten. products, to
use double moulds, the corresponding parts of which are applied and
moved progressively or intermittantly. Sometimes two or more longi-
tudinal wedge-shaped sections are employed, so constructed that when
arranged they will form a cylinder.
Figure 16 represents a section of the chamber (n) and casting bed plate
D, which shews the method whereby I cast entire patterns composed of
numerous figures of different colors, in which A represents a pattern,
of which the Figures 1, 2, 3, 4, are cast in different colored material
by the following process-A series of rollers, marked 1st, 2nd, 3rd,
and 4th roller, are adjusted horizontally between the oven side walls
(y), by suitable bearings, immediately over the line of elevation of the
plates D. Each of these rollers has on its surface raised figures, as
numerous as the figures of the color it represents. When the casting
bed plate has received the molten product, it passes under roller 1st,
and receives impressions corresponding to the raised figures thereon.
As soon as the plate and casting pass from under roller 1, these cavities
are filled with a particular color. The casting is then moved along until
it passes under roller 2.
From this roller it receives impressions for
a second color, which are immediately filled with that particular color.
And this process is repeated through as many rollers as there are Figures
of different colors to be added to the pattern.
It is also found necessary to use molds of the kind shewn in Figures
21, 23, and 24; Figure 21 representing a double relief mould for casting
hollow articles, said mould consisting of a hollow or solid core (Z"),
the base of which when not in use, rests upon the fixed platform (m³),
but when fixed for casting is raised by the screw (n) to the position
shewn. On each side of the core (2) there is a side piece (p"), which
slides freely in a horizontal direction to and from the core (Z) upon
its base (q), which works in a groove in the standard (). These several
parts being adjusted, the molten product is poured through the opening
(a), between the central core (Z) and the side pieces (p), forming a
hollow casting (6) of any desired shape. As soon as the casting has
set or become solid, the central core is lowered by turning the screw,
and the side pieces are slid back by their handle R. The casting is
thus set free for removal into the annealing oven.
In forming certain kinds of castings, I also use the moulds repre-
sented in Figures 23 and 24. Figure 23 represents an horizontal plan
of a box or close oven or wagon, open or closed at the top, and having

page_text: side openings (7) in the walls (y). Through the openings (d), bars or
plates (a) of stone or metal, either wedge-shaped or hemispherical,
are inserted, reaching through the oven, and extending on either side
of the wall (), by which bars the interior space of the oven or wagon
is divided into various compartments. The molten product having
been poured from oven top into the oven or wagon between the bars (a'),
the bars are speedily withdrawn as soon as the casting is set, and the
casting is then annealed.
In addition to the mechanical operation of the omega furnace, as
above described, I use the chamber (a) and the channel (e) for refining
the metallic and mineral products, and for coloring the same by mixing
therewith said products, while fluid, and immediately after their with-
drawal from the omega furnace, salt, metallic sulphurets, alkalis, pure
metals, acids, and other suitable substances.
Having now described the said Invention, as communicated to me,
what. I claim under the above in part recited Letters Patent is,-
1st, the process, substantially as herein described, for working
metallic ores, to impart a value to the mineral as well as the metallic
products.
2nd, the manner, substantially as described, of constructing and using
the alpha furnace (so called) for working metallic ores.
3rd, the manner, substantially as described, of constructing and using
the omega furnace (so called) for working the products of metallic ores.
4th, the manner, substantially as described, of constructing and using
the two furnaces in combination for working metallic ores and their
products.
5th, the formation of the metallic ores, fluxes, and fuel, as described,
into hollow and perforated blocks for smelting.
6th, the manner, substantially as described, of constructing and using
a series of moveable boxes, plates, tables, or wagons, to traverse the
body of a smelting furnace for roasting and beating metallic ores, fluxes,
&c. therein, and feeding the blast furnace, boshes, or hearth with
heated ore.
7th, also the manner of using the same for annealing iron or other
metals or minerals, either alone or in contact with minerals, ores, or
oxides, immediately after their reduction from the ore, or after being
cast into pigs, bars, or other shape, whether working in an oven of
an annular or other form, constructed on the principle of the omega
furnace.
1
8th, the mode of gradually annealing fused metallic and mineral
substances, by passing them from the hot to the cold end of an annealing
chamber, upon and by means of said wagons.

page_text: 9th, the manner, substantially as described, of constructing said
series of tables or table, whether employed in casting, annealing; or
other analogous purpose, with the sides and ends, so as to make a close
joint with each division of the series or table, and with the sides of
the oven chamber in and through which it moves; said table constituting
at all times a complete and unbroken hearth or moveable traversing
floor to the chamber, so that while in action it may be subjected to
currents of hot air on its upper simultaneously with the passage of cold
air along its under surface.
10th, the mode of moving said tables, plates, &c. by means of a system
of wheels and pinions arranged substantially as described, so as to
employ concentrated force and slow movement upon the plates passing
through the furnace or oven, and at the same time, when desired, to
use diffused or weaker power. and increased motion upon the plates
returning outside the oven to the place of departure.
11th, the mode, substantially as described, of smelting the ore, heated
as herein mentioned, in the boshes of a blast or other smelting furnace,
and also in the use and application, in the manner as described, of the
escape heat issuing from the boshes to heat and roast the ore when
descending through either an horizontal or inclined furnace body into
said boshes.
12th, the manner, substantially as described, of graduating and
regulating the temperature of annealing ovens by flues and dampers.
13th, the mode, substantially as described, of constructing and using
a channel or chamber connected with or adjoining the hearth of a blast
or other smelting furnace, for the purpose of condensing and refining
molten metallic and mineral products, and also of refining such products
by the admixture of salt, sulphate of iron, copper, alkalis, alkaline
earths, pure metals, acids, and such substances employed by chemists
as re-agents found adapted for the purpose.
14th, the manner, as described, of constructing and using for
annealing mineral products a terminal warm or heated reception or
store room, and an oven with the moveable cylindric casing, as
described.
15th, the mode, substantially as described, of producing different
colored designs, figures, or patterns upon fused or plastic mineral
products by means of successive pattern rollers, presses, or moulds, in
connection with the mode of supplying the coloring matter.
16th, the construction and use, as herein described, of wedge-shaped
double semicylindric and double relief moulds, and the mode described
of fixing and withdrawing continuously or intermittingly the several

page_text: parts of double moulds for producing solid or hollow castings of one
or more colors.
17th, the use and employment of a roller or rollers working in con-
junction with an interior and posterior inclined press, as described, for
pressing and shaping plastic mineral products.
18th, the mode, substantially as described, for using the mould and
removing the same from castings after they have set and. before. the
annealing.
In witness whereof, I, the said John Talbot Pitman, have hereunto
set my hand and seal, on this Eleventh day of August, in the
year, of our Lord One thousand eight hundred and fifty-seven.
JOHN TALBOT PITMAN. (L.S:)