Improvements in Calcining Furnaces.
Year: 1896

page_text: Date of Application, 5th May, 1896-Accepted, 8th Aug., 1896
COMPLETE SPECIFICATION.
Improvements in Calcining Furnaces.
I, ARTHUR HARVEY WETHEY, Metallurgist, of 312 West Quartz Street
Butte, in the County of Silver Bow, and State of Montana, United States of
America, do hereby declare the nature of my invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The object of the invention is to provide a new and improved calcining and
desulphurizing furnace, designed for rapidly and thoroughly desulphurizing ores
and other material in a ground, pulverized, crushed or concentrated state, and
without loss or waste of material, said furnaces being arranged in such a manner
that the ploughs, stirrers and like devices for agitating and moving the material in
the hearths are actuated and carried forward by machinery located on the outside
of the hearths.
The invention consists principally of a hearth provided in one or both of
its sides with continuous longitudinal slots for the passage of the stirring devices.
The invention further consists of two parallel structures having hearths, a
rake or similar stirring apparatus adapted to operate over each hearth, and
operating devices located between said structures and connected with both of said
rakes.
The invention also consists of certain parts and details and combinations of
the same, as will be fully described hereinafter and then pointed out in the
claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar characters of reference indicate corresponding parts
in all the figures.
Figure is a longitudinal section of the improvement as arranged for two
parallel furnaces, the section being taken on the line 1-1 of Figure 3;
Figure 2 is a longitudinal section of the same, on the line 2-2 of Figure 3;
Figure 3 is an enlarged cross section of the same, on the line 3-3 of
Figure 2;
Figure 4 is an enlarged transverse section of one side of the hearth;
Figure 5 is a side elevation of the improvement, as arranged for a single
furnace;
Figure 6 is an enlarged cross section of the same, on the line 6-6 of
Figure 5;
Figure 7 is an enlarged sectional plan view of the same, on the line 7-7 of
Figure 5;
Figure 8 is an enlarged side elevation of the tripping door arrangement;
Figure 9 is a cross section of the same, on the line 9-9 of Figure 8;
Figure 10 is an enlarged side elevation of part of the improvement, on the
line 10-10 of Figure 6;
Figure 11 is a cross section of the improvement, showing the end door; and
Figure 12 is a sectional side elevation of the same, on the line 12-12 of
Figure 11.
The improved furnace, illustrated in Figures 1, 2, 3, 4, is provided with two
furnaces A, A¹, placed parallel one to the other and both alike in construction, so
that it suffices to describe but one in detail.

page_text: Each furnace A, A', is provided with a series of longitudinally-extending
compartments B, B1, B2, B3, located one above the other, as plainly shown in
Figure 2, and separated from each other by dead air spaces C. The lowermost
compartment B is connected at its right-hand end by a vertical channel D with
the corresponding end of the next compartment B₁, and the latter is connected at
its left-hand end by a corresponding vertical channel D' with the corresponding
end of the third compartment B2, and the latter is connected at its right-hand end
by a channel D2 with the corresponding end of the uppermost compartment B³.
The latter is provided in its roof or top wall, and at the left-hand end with a
charging opening D³ through which the material to be treated is introduced into
the corresponding furnace A or A'. In the bottom of the lowermost compart-
ment B and near the left-hand end thereof, is arranged an outlet D' through
which the roasted or desulphurized material is finally discharged from the furnace
in the manner hereinafter more fully described, the material dropping into a car
or other suitable vessel located below the said outlet opening D; see Figure 2.
In the lowermost compartment B, and at the left of the outlet opening D' is
arranged a heat inlet opening E connected with a fire box F of any approved
construction, see Figure 3, so that fuel burning in the said fire box discharges its
heat through the opening E into the lowermost compartment B along which the
heat passes, to finally pass by the channel D into the next compartment B¹, located
above it, to pass along the same and to then pass through the channel D' into the
third compartment B, along the same, and through the channel D2 into the
uppermost compartment B from which it finally passes through an opening E
into the chimney G; see Figures 2 and 3.
The material under treatment passed into the uppermost compartment B
through the opening D³, travels in an opposite direction to the movement of the
gas and heat above described, that is, it passes first along the compartment B³,
drops through the channel D' into the compartment B2, is then moved along the
same to drop through the channel D' into the compartment B¹ to be moved along
the latter to then drop through the channel D into the compartment B to be moved
along the latter to be finally discharged through the outlet D' into the car located
below it. By this arrangement, the material is first subjected to heat of com-
paratively low temperature and is gradually moved into a higher temperature,
reaching its highest point previous to the material being discharged through the
opening D', as above explained.
Now, in order to move the material through the several compartments in the
manner described, the following device is provided. Through each of the
compartments are adapted to pass stirring devices, each having a number of shovels
or ploughs H secured on a transversely-extending shaft I reaching from one
furnace to the other and extending into the corresponding compartments thereof,
as will be readily understood by reference to Figure 3. Each shaft I is engaged
outside of the inner walls of the furnace A and A', by cross heads J secured on
endless travelling chains K each passing over the pulleys L, L1, L2, L³ and L, of
which the pulleys L, L' and L are arranged a suitable distance from one end of
the furnace, while the other pulleys L' and L' are similarly arranged a suitable
distance from the other end of the furnace, as will be plainly seen by reference to
Figure 1.
"
It will further be seen that the several pulleys are located one above the other
in such manner that the several runs of the endless chain K pass in alignment with
the respective compartments B, B1, B2, B3, so that a single shaft is carried
successively from one compartment to the next one, and in an opposite direction to
its former movement.
In order to support the runs of the chain K between the corresponding oppositely
arranged sets of pulleys, I provide carrier pulleys N journaled in suitable bearing
supported on a skeleton frame of the furnace, between the inner walls thereof. In
order to support the shafts I in the proper position during their passage through
the several compartments, I provide each shaft with an exterior wheel O travelling

page_text: in a correspondingly-shaped rail O' secured to the outer face of the inner wall of
the corresponding furnace A or A. In order to sustain the inner ends of the
shafts I, I provide the same with similar wheels O' travelling on rails O³ extending
within the respective compartments B, B1, B2 and B³.
Now it will be seen that when the chain K receives a travelling motion by
rotating any one of the pulleys L, L, L, L³ or L, a travelling motion is given to
the several shafts I so that the latter pass successively through the several
compartments B, B1, B2, B3, to move the material by their shovels H in the
direction above described, it being understood that the material is first moved in
the uppermost compartment B³ from the inlet opening D³ to the channel D² through
which the material drops into the next following compartment B² to be moved
along the same to be finally permitted to drop through the channel D¹ into the
compartment B₁ and so on as above described.
In order to prevent the air from passing into the compartment at the ends and
inner walls, I provide the inner walls with self-closing doors P, which are opened
by the moving shafts I, and the ends of the said compartments are provided with
similar doors Qadapted to be opened by the shovels H and to close, as soon as the
shovels or ploughs have passed into or from the respective end.
It will be seen that the shovels or ploughs in their movement through the
several compartments stir up and agitate the material contained therein, at the
same time moving it gradually forward to permit it to drop to the next following
compartment, as above described, so that the material is thoroughly subjected to
the action of the heat passing through the compartments in an opposite direction
to the movement of the material. In order to hold the endless travelling chain K
sufficiently tight, I mount the pulleys L' and L³ on longitudinally-adjustable
bearings R of any approved construction and arranged to take up any slack
occurring in the chain.
The furnaces A and A' are preferably constructed as shown, and are provided
with a metallic skeleton frame, and a brickwork composed principally of the
outer walls T, the inner walls T¹ and the arches T2, as is plainly illustrated in
Figure 3.
The metallic skeleton frame is provided with sets of channel beams placed
suitable distances apart on each outer face of the outer walls T, each set of
channel beams being composed of two channel beams S tied together, each two
oppositely arranged sets of beams forming a support for a transversely-extending
main I-beam S which acts as a binder or back-stay for both furnaces A, A'. The
beams S, S', of a set are tied together by rods S2, one on each side of the main
beam S¹, as plainly shown in the drawings. Short beams S³ are employed to
connect the inside walls T of the two furnaces with each other, and these beams S³
rest on longitudinal beams S' set or built in the inner walls T¹. The I-beams S'
and S3 support channel beams S which in turn, support the track rails O' on which
the wheels O travel, as previously described.
From the main I-beams S are suspended secondary I-beams S. By means of
special castings S', these beams S support one side of the arches T2 above the
hearth of each compartment B, B', B2 and B3; see Figure 3. The castings S' are
securely bolted to the main I-beams S¹ and are bolted together through the
secondary I-beams S which have elongated holes so that the beams can expand or
contract freely.
From the I-beams S, the arches or roofs T2 are swung over to the main outside
walls T of the furnaces A and A', and the said beams also support short walls T³
extending transversely and reaching to the floor of the next compartment above so
as to form the dead air spaces C previously described. The air spaces C are
preferably provided with ventilating doors. On the ends of the arches T are
secured transversely-extending plates S8 on which the end doors Q are hung, it
being understood that the door at one end of a compartment swings inward,
while the door at the other end swings outward, see Figure 2, full and dotted
lines.

page_text: The hearth T of each compartment B, B', B' or B is made of a fireproof
material and set on a metallic plate S supported on longitudinally-extending
T-rails S resting on the main beams S', as will be readily understood by reference
to Figure 3. The plates S are made in sections of sheet iron or steel, and placed
suitable distances apart to allow for expansion.
It will be seen that by a furnace constructed in the manner described, the
material is readily calcined or desulphurized, and all the working parts of the
furnaces can be readily reached so that repairs of all kinds can be quickly effected
at any time. The furnaces are so constructed that they can be enlarged at will,
either by increasing the height by the addition of more compartments or by
increasing the length of the compartments already built, and increasing the
number of fire boxes F, and chimneys G, as the latter must be sufficient to remove
all fumes and gases and allow sufficient draft for the processes of calcining to
proceed in a proper manner.
It will also be seen that the arrangement of the main beams permits a free
expansion and contraction without causing any damage to the furnace, and also
permits of increasing the size of the furnace at any time in the manner above
described. The said beams also allow the free passage of the ploughs H into and
out of the compartments at the ends thereof, thus permitting the ploughs to cool
after they have passed once through the hot ore in one compartment and before
again entering the next following compartment.
It will also be seen that the working parts of the furnaces such as tracks, chains
and so on, are principally located outside of the compartments, thus preventing
wear and tear which would be caused by heat if they were located inside of the
compartments.
It will further be seen that the secondary beams S are freely suspended and are
thus free to expand and contract without injury to the arches supported by the
same. It will also be seen that the ore or material passing from one chamber to
another falls a considerable distance, so that any lumps or balls contained in the
material are broken upon striking the hearth of the next following lower
compartment. The falling of the ore through the heat moving in an opposito
direction, increases the rapidity of the desulphurizing process.
In the furnace illustrated in Figures 5 to 12 inclusive, but one furnace is shown,
formed in its sides with continuous longitudinal slots extending from one end of
the furnace to the other for the passage of the ends of the ploughs or stirrers.
This furnace is provided with a number of hearths A10, A", A and A, located
one above the other, and connected with each other by openings A (Figure 7),
so that a continuous chamber is formed for the ore or other material to pass
through.
The upper hearth A" is provided on one end and preferably in the top, with
an ore supply hopper B, for feeding ore and like material into this end of the
hearth A¹³, the ore then being moved forward in the direction of the arrow a
along the bottom or floor of the hearth by stirring and moving devices Co, until
the ore reaches the opening A", through which it drops into the right-hand end of
the next lower hearth A¹. The ore is now moved to the left; that is, in the
inverse direction of the arrow a¹ by the stirring devices C on their return
movement, until the ore reaches and drops through an opening similar to the
opening A, and located in the bottom of the hearth A near the left end thereof
The ore now passes into the third hearth A" and is moved along the same in the
direction of the arrow a' by another set of stirring devices Co, until it reaches and
drops through an opening similar to the opening A, into the right-hand end o
the lower hearth A, in which the ore is moved along to the left by the returning
stirring devices C, to finally pass into hoppers A from which the ore can be
discharged into a wagon or cart D, arranged below said hoppers, as indicated in
Figure 5. See also Figure 6.
On each side of the furnace is arranged a fire box E, of any approved
construction, and receiving its fuel supply from a delivery chute Fo, as indicate

page_text: in Figure 5. The products of combustion pass from the fire box through a
channel E into the hearth A" at the top thereof and next to the ore supply, so
that said products of combustion travel forward in the hearth A13 with the ore, to
pass into the next hearth A2 and along the same to the left, then down through
the hearth A and forwardly along hearth A" a suitable distance, to then pass
through an opening or channel G to the upper ends of stacks G, arranged on
the sides of the furnace. By this arrangement the combustion products and the
fumes of the two upper hearths A1 and A2 travel downward, to reach the
stacks G10, while the fumes in the two lower hearths A" and A travel upward
to reach said stacks. The lower ends G12 of the stacks G10 discharge into a
longitudinally extending flue H, arranged under the lowermost hearth A¹º, to
carry the waste gases to a chimney connected with said flue.
The sides of each hearth A", A", A12 or A13 are formed with longitudinally-
extending slots A, extending from one end of the hearth to the other, and
normally closed by suitable trip doors 110, shown in detail in Figures 8 and 9 and
hereinafter more fully described.
Through these slots A are adapted to pass the outer ends of stirring
devices Co, C, which latter are supported at their extreme outer ends in
carriages J, Jadapted to travel longitudinally on the outer sides of the furnace,
and shielded from the heat in the hearth by the doors 110 above mentioned, said
carriages being propelled forwardly in the direction of the arrow a¹ on the outer
sides of the hearths A3 and A", and returned in the opposite direction on the outer
sides of the hearths A2 and A10 by suitable propelling mechanisms, preferably in
the form of endless chains or cables K, K", respectively, passing over driven
pulleys L, L", respectively, on the front end of the furnace and over idle
pulleys L, L, respectively, arranged on the opposite or rear end of the furnace.
See Figures 5 and 7.
In order to render the above described arrangement practical, I construct the
furnace in detail as follows:
Two parallel rows of posts N10, N" are erected on suitable foundations, and the
posts are placed suitable distances apart, with the posts in the rows arranged
directly opposite each other, as indicated in Figure 7. Each post N10 or N is
formed of two vertically-disposed beams connected with each other by castings or
brackets, supporting transverse beams P connecting two opposite posts with
each other, and from said transverse beams are suspended by suitable U-shaped
bolts Q the longitudinal I-beams Q10, Q for forming the sides of the hearth and
for supporting the brick roof arches Q for the hearth, as will be readily understood
by reference to Figure 6. Castings Q3 bolted to the posts N10, N, engage the
longitudinal I-beams Q1, Q", so as to brace the latter. To the under side of the
longitudinal beams Q10, Q are securely bolted auxiliary beams or augle-irons R10,
opposite to which are arranged like angle-irons R", forming with said angle-
irons R10 the slots A" for the passage of the ends of the stirring devices travelling
through the hearth.
Resting on the transverse beams P10 are longitudinally extending I-beams S10,
carrying sheets or plates S", on which are supported the floors S12 of the hearths,
made of brick or like material, it being understood that each set of transverse
beams is for supporting the floors for the hearths A", A2, A3, the floor for the
lowermost hearth being directly built up from the ground by suitable brickwork.
The angle-irons R previously referred to, form braces for the lower sides A17
of the hearth, the sides extending a short distance above the floors S12, to prevent
the ore or like material under treatment from passing into and through the
slits A to the outside. The angle-irons R" are securely bolted to castings or
brackets T10, attached to the vertical beams of the posts N10, N", the inner ends
of said brackets being preferably walled in the sides A", as indicated in Figure 6.
The brackets To also support longitudinally-extending rails J2, on which travel
the wheels of the carriages J, J", it being understood that said rails and
carriages are a suitable distance from the sides of the hearth, so that the heat

page_text: from within the hearth does not injure said carriages and the propelling mechanism
for the same; thus sufficient room is left between the sides of the hearth and the
posts No, N for the carriages and working machinery used for propelling the
stirring devices.
Each arch Q supports a transversely-extending brick wall Q on each side
of a transverse beam P10, so that the latter is protected from the heat as there is
an air space around the beam from outside to outside of the furnace. The brick
walls Q connect with the floor above the arch, thereby forming dead air spaces
for preventing loss of heat by radiation, and insuring a light but strong construction
of the furnace.
Each of the stirring devices C10, C" is provided with shovels or stirrers C",
secured angularly on a hollow tube or shaft C³, connected at its outer ends by a
threaded sleeve C to a metallic cable C", attached to a plate J13 forming the
frame for the carriage J10 or J", said plate supporting the carriage wheels "
which travel on the track rails J12 inside of the posts N, N". The driving
pulleys L, L are driven by suitable belts or cables from an overhead pulley L,
and the idle pulleys L2 and L18 are preferably mounted in journal boxes Lis
fitted to slide longitudinally in suitable guideways, and engaged by weights L
for holding said journal boxes and idle pulleys in an innermost position, to hold
the chains or cables K10, K" in a comparatively taut condition.
Each outer end of a hearth is closed by suitable doors U10, see Figures 7 and
11, preferably two in number, and mounted to swing, and each carrying on its
pintle U a counterbalancing weight U to permit the door to open for the
entrance or exit of the stirring devices, said door then automatically closing as
soon as the stirring devices have passed. The two doors U10 at each end are
placed far enough apart so that one is closed while the other is opened by the
stirring device, to prevent any escape of the heat within the hearth. The doors 110
for the slots A and shown in detail in Figures 8 and 9. are preferably pivoted
at I at one upper corner to the angle-iron R, while the lower edge is adapted
to rest on a suitable lug I, secured to the outside of the lower angle-iron R",
When the sleeve C of a stirring device strikes the edge of the door I¹º, the
latter is swung upward into the position shown in Figure 8, to permit the passage
of the sleeve; and when the latter has passed a door, then the door swings back
by its own gravity to its normal position, resting with its lower edge on the lug 12,
as will be understood by reference to said Figures 8 and 9. The fire boxes E¹º
are supported from some of the posts N10, N1, and in addition columns E12 are
employed, as will be readily understood by reference to Figure 6.
By the arrangement described, a furnace of any desired length can be built,
It will be understood that I do not
or an existing furnace lengthened if desired.
limit myself to the connection of the fire boxes E10 with the upper hearth A¹³ at
the point indicated, as the fire boxes can be connected with any of the hearths at
any desired point. See for instance the points marked X, X' in Figure 5.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is,
1. A calcining furnace, provided with two parallel structures having hearths, a
rake or similar stirring apparatus adapted to operate over each hearth, and
operating devices located between said structures and connected with both of said
rakes, substantially as shown and described.
2. In a calcining furnace, the combination with a furnace having an elongated
slot in each of the side walls, said slot extending from one end of the furnace to
the other, substantially as shown and described.
3. A calcining furnace, comprising a series of roasting compartments located
one above the other and connected in such a manner as to form a continuous
chamber for the passage of the ore and the heat, the latter travelling in an
opposite direction to the movement of the ore, and a stirring and conveying device

page_text: comprising an endless travelling chain having its several runs passing longitudinally
outside the said compartments, and ploughs or shovels carried by the said chain
and adapted to travel through the several compartments to stir up the material
under treatment, and to move the same forward to permit it to drop from a
compartment into the next lower one at or near the ends thereof, substantially as
shown and described.
4. A calcining furnace, comprising a series of roasting compartments located one
above the other, vertically-disposed channels connecting the compartments with
each other at opposite ends so as to form a continuous chamber for the passage
of the material to be treated, a fire box discharging into one end of the lowermost
compartment, a chimney connected with the end of the uppermost compartment to
circulate heat from the said fire box through the several compartments, and a
stirring and conveying device comprising an endless travelling chain having its
several runs passing longitudinally outside the said compartments, shafts carried
by said chain, and stirrers or shovels secured on said shafts and adapted to pass in
and through said compartments, substantially as shown and described.
5. A calcining furnace, comprising a series of roasting compartments located
one above the other, vertically-disposed channels connecting the compartments
with each other at opposite ends so as to form a continuous chamber for the
passage of the material to be treated, a fire box discharging into one end of the
lowermost compartment, a chimney connected with the end of the uppermost
compartment to circulate heat from said fire box through the several compartments,
a stirring and conveying device comprising an endless travelling chain having its
several runs passing longitudinally outside said compartments, shafts carried by
said chain, stirrers or shovels secured on said shafts and adapted to pass into and
through said compartments, and doors on the ends and inside of said compartments,
substantially as shown and described.
6. A calcining furnace, comprising a series of roasting compartments located one
above the other, vertically-disposed channels connecting the compartments with
each other at opposite ends so as to form a continuous chamber for the passage of
the material to be treated, a fire box discharging into one end of the lowermost
compartiment, a chimney connected with the end of the uppermost compartment to
circulate heat from said fire box through the several compartments, a stirring and
conveying device comprising an endless travelling chain having its several runs
passing longitudinally outside the said compartments, shafts carried by said chain,
stirrers or shovels secured on said shafts and adapted to pass into and through said
compartments, longitudinal rails, and wheels held on said shafts and adapted to
travel on said rails to properly support said shafts, substantially as shown and
described.
7. The combination with the parallel furnaces having longitudinal slots in their
adjacent sides with movable doors, of ploughs or stirrers extending into the furnaces
through said slots and having an operating mechanism intermediate of the furnaces
for operating them simultaneously, said doors being constructed to move and allow
the passage of the ploughs and then return to place after they have passed,
substantially as shown and described.
8. A calcining furnace, comprising an outer wall, an inner wall, arches between
the inner and outer walls to form compartments located one above the other, sets
of channel beams arranged on the outer faces of the outer walls, transverse I-beams
connecting corresponding sets of channel beams with each other, secondary I-beams
arranged longitudinally and suspended from said transverse I-beams, the said
secondary beams forming a support for one side of the said arches, longitudinally-
extending rails supported on said transverse I-beams, and sheet metal plates
supported on said rails and adapted to carry the bricks forming the hearth of the
compartment, substantially as shown and described.
9. A calcining furnace, comprising a hearth having continuous longitudinal
slots in the sides for the passage of the ends of stirring devices, and supports for

page_text: the outer ends of the stirring devices, located at a distance from the sides of
the hearth, substantially as shown and described.
10. A calcining furnace, comprising a series of hearths located one above the
other, and each provided in its sides with continuous longitudinal slots for the
passage of the outer ends of the stirring devices, and tripping doors for normally
closing the continuous slots and arranged for the passage of the outer ends of the
tripping devices, substantially as shown and described."
11. A caleining furnace, comprising a series of hearths located one above the
other, and each provided in its sides with continuous longitudinal slots for the
passage of the outer ends of the stirring devices, tripping doors for normally
closing the continuous slots and arranged for the passage of the outer ends of the
tripping devices, and carriages travelling on rails arranged a distance away
from the sides of said hearths, said carriages supporting said stirring devices,
substantially as shown and described.
12. A calcining furnace, comprising a series of hearths located one above the
other, and forming a continuous roasting chamber through which is adapted to
travel the ore or other material to be treated, fire boxes discharging into one of
said hearths, and stacks leading from one of said hearths for carrying off all the
fumes, substantially as shown and described.
13. A calcining furnace comprising a series of hearths located one above the
other, and forming a continuous roasting chamber through which is adapted to
travel the ore or other material to be treated, fire boxes discharging into one of
said hearths, and stacks leading from one of said hearths for carrying off all the
fumes, said stacks discharging at their lower ends into a longitudinal flue connected
with a chimney, substantially as shown and described.
14. A. calcining furnace comprising rows of posts, transverse beams supported
thereby, and longitudinal I-beams carried by said transverse beams and supporting
the floors of the hearth, substantially as shown and described.
15. A calcining furnace comprising rows of posts, transverse beams connecting
opposite posts with each other, longitudinal I-beams carried by said transverse
beams, floors supported by said I-beams, a second set of longitudinal I-beams
suspended from said transverse beams, and roof arches carried by the last
named I-beams, substantially as shown and described.
16. A calcining furnace comprising rows of posts, transverse beams connecting
opposite posts with each other, longitudinal I-beams carried by said transverse
beams, floors supported by said I-beams, a second set of longitudinal I-beams
suspended from said transverse beams, roof arches carried by the last mentioned
I-beams, brackets attached to said posts, and rails carried by said brackets,
substantially as shown and described.
17. A calcining furnace comprising rows of posts, transverse beams connecting
opposite posts with each other, longitudinal I-beams carried by said transverse
beams, floors supported by said I-beams, a second set of longitudinal I-beams
suspended from said transverse beams, roof arches carried by the last mentioned
I-beams, brackets attached to said posts, rails carried by said brackets, and angle-
irons secured to the suspended I-beams and said brackets, for forming the
longitudinal slots in the sides of the hearths, substantially as shown and
described.
Dated this 5th day of May 1896.
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.