IMPROVEMENTS IN RETORTS, FURNACES, AND OTHER CLOSE HEATING VESSELS OR CHAMBERS."
Year: 1875

page_text: LETTERS PATENT to Robert James Wood, of the City of Glasgow,
in the County of Lanark, North Britain, Clockmaker, for the
Invention of "IMPROVEMENTS IN RETORTS, FURNACES, AND OTHER CLOSE
HEATING VESSELS OR CHAMBERS."
PROVISIONAL SPECIFICATION left by the said Robert James Wood
at the Office of the Commissioners of Patents, with his Petition,
on the 5th June 1875.
I, ROBERT JAMES WOOD, of the City of Glasgow, in the County of
Lanark, North Britain, Clockmaker, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN RETORTS, FURNACES, AND OTHER
CLOSE HEATING VESSELS OR CHAMBERS," to be as follows:-
This said Invention has reference to a peculiar construction of close
heating chamber and its essential fittings or connections, adapted either
for intermittent or regular and constant charging and discharging of the
material being heated and treated therein, and it has the additional

page_text: advantage of being suitable for a great variety of purposes, such as for
evaporating liquids, the destructive distillation of shale, coal, and other
substances for the making of illuminating or other gases, and for
calcining, baking, or other purposes for which retorts, furnaces, ovens,
and kilns are employed; besides being simple, with few parts to get out
of order.
The nature and novelty of this Invention consist in forming the close
chamber for heating and treating the substance to be operated upon of a
circular, preferably cylindrical shape, with flat, domed, or conical roof,
and with a flat bottom or floor, but with an annular part of this near the
outer circumference and the lower part of the side walls, through which
the whole is heated, made of segmental plates of cast or malleable iron
or steel, closely bolted or rivetted together fluid-tight, and having the
floor heating plates formed with annular raised conical or curvilinear
ridges, with flat annular recesses between them for giving great heating
surface, and with an inner edge or ridge, all for holding the material to be
treated, and the other parts of this floor, walls, and roof may be made
of brickwork or other material capable of withstanding the heat
required; or the whole inner shell may be made of iron with non-
conducting material outside. One, two, or more annular flues are
formed below the said outer iron heating parts of the floor, and round
the lower heating part of the iron walls, with a sufficient number of
radial heating furnaces ranged equally round below these, and from
which the heated products of combustion would flow up into and pass
round the outer or inner flue, and thence into and round the next and
following flues in succession, from whence they are led after heating the
iron surface of the chamber into the bottom of the chimney, which is
either built in the centre of the whole or at the extremity of the outer
flue, which passes round the side walls. The heated products of com- .
bustion in these flues rise up into and heat the under surface of the
recesses of the corrugated or A shaped ridges of the bottom heating
plates, so as to heat them and the material to be heated and treated,
which is charged regularly or intermittently into the hollows between the
ridges on the upper surface of the floor.
When the material to be treated requires to be turned over or agitated, a
on the surface of the b

page_text: three (or more) antifriction balls or other equivalents in a groove or
grooves formed on its under side, and in a corresponding stationary
groove or grooves below it, these grooves being provided with a guard to
prevent chokage with soot or dust, the table or frame having screw or
pitch teeth on its outer periphery for a screw or pinion to work into
through a recess in the side wall of the chamber, and which is keyed on
a shaft revolving in bearings in a small closed-in compartment outside
the heating chamber, and driven by or from any convenient or adjacent
prime moving shaft. The said turning table or frame carries the pendent
inclined or revolving agitators or scrapers, which are made to yield to
the inequalities of the corrugated surfaces; or otherwise the frame of
these agitators and scrapers might be made stationary, and the annular
heating floor with the material to be treated on it might be made to
revolve on like balls and grooves, actuated in the same or an equivalent
manner to the turning table or frame just described; or in some cases a
false bottom, plain or corrugated, might be made to revolve in like
manner between the stationary bottom and the agitators or scrapers.
In those cases when the heating or carrying floor or bottom revolves,
the material may be fed in slowly and regularly through a radial hopper
in the roof, with radial corrugated or vaned rollers working into each
other over one part of the heated annular or corrugated plates wide
enough to feed in a constant and regular quantity of the material in
proportion to the differential circumference of the corrugated surfaces
and the speed of these vaned rollers, which may be driven from the
same prime moving shaft as the revolving floor or frame.
For discharging the material when treated after one or more revo-
lutions round the heating chamber a part of the corrugated or stationary
floor may be hinged and let down by hand or automatically, and a scoop
is provided and let down into the corrugations of the floor at such an
angle that the material would easily and readily rise up the incline and
fall over its upper edge into a receptacle provided to receive it through
the said opening in the moveable floor or at the one side.
When the apparatus is used as an oven or kiln, or when stirring or
agitation is not required, the scrapers are dispensed with, and the interior
is filled with shelves, or racks, or cages, as may be necessary, in which
case also the door or opening will be in the outside of the casing or
retort, and when used for the production of gases the necessary pipes

page_text: and other ordinary appliances for drawing off these would be fitted
thereto in the usual manner adopted in other retorts and gas producing
furnaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert James Wood in the Great Seal Patent
Office on the 4th December 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
JAMES WOOD, of the City of Glasgow, in the County of Lanark, North
Britain, Clockmaker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of June, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert James Wood, Her
special licence that I, the said Robert James Wood, my executors,
administrators, and assigns, or such others as I, the said Robert
James Wood, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN RETORTS, FURNACES, AND OTHER CLOSE
HEATING VESSELS OR CHAMBERS," upon the condition (amongst others)
that I, the said Robert James Wood, 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
formed, 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.
per-
NOW KNOW YE, that I, the said Robert James Wood, 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 in writing, reference being had to the several

page_text: Figures and letters of reference on the accompanying two Sheets of
Drawings, that is to say :-
My said Invention has reference to a peculiar construction of close
heating chamber, and its essential fittings or connections adapted either
for intermittent or regular and constant charging and discharging of the
material being heated and treated therein, and it has the additional
advantage of being suitable for a great variety of purposes, such as for
evaporating liquids, the destructive distillation of shale, coal, and other
substances for the making of illuminating or other gases, and for
calcining, baking, or other purposes, for which retorts, furnaces, ovens,
and kilns are employed, besides being simple, with few parts to get out
of order.
"
The nature and novelty of this Invention consist in forming the
close chamber for heating and treating the substance to be operated
upon, of a circular or annular, preferably cylindrical shape, with flat,
domed, or conical roof, and with a flat bottom or floor, but with an
annular part of this near the outer circumference, and the lower part of
the side walls within or through which the whole is heated made of
solid annular or segmental plates of cast or malleable iron or steel
closely bolted or rivetted together fluid-tight, and having the floor
heating plates formed with annular raised conical or curvilinear ridges,
with flat annular recesses between them for giving great heating surface,
and with an inner edge or ridge, all for holding the material to be
treated, and the other parts of this floor, walls, and roof may be made of
brickwork or other material capable of withstanding the heat required,
or the whole inner annular heating and treating close vessel or shell
may be made of iron, with non-conducting material outside. One, two,
or more annular flues are formed below the said outer iron heating parts
of the floor and round the lower heating part of the iron walls, with a
sufficient number of radial heating furnaces ranged equally round below
these flues, and from which the heated products of combustion flow up
into and pass round the outer or inner flues, and thence into and round
the next and following flues in succession, or a number of these at once,
from whence at one part they are led, after heating the iron floor or
surface of the chamber, into the bottom of the chimney, which is either
built in the centre of the whole or at the extremity of the outer flue
which passes round the side walls. The heated products of combustion
in these flues rise up into and heat the under surface of the recesses

page_text: between the corrugated or A shaped ridges of the bottom heating plates
so as to heat them and the material to be heated and treated which is
charged regularly or intermittently into the hollows between the ridges
on the
upper inner surface of the floor.
When the material to be treated requires to be turned over or agitated,
or the surface of the heating or corrugated plates or bottom requires to
be scraped or cleaned, an annular turning table or frame is arranged to
revolve on three (or more) antifriction balls or other equivalents in a
groove or grooves formed on its under side, and in a corresponding
stationary groove or grooves below it, these grooves being provided with
a guard to prevent chokage with soot or dust, the table or frame having
screw or pitch teeth on its outer periphery for a screw or pinion or other
equivalent as a pitch or plain groove for a pitch chain or wire rope to
work into through a recess in the side wall of the chamber, the pinion
or small pulley actuating this table frame is keyed on a shaft revolving
in bearings in a small closed-in compartment outside the heating
chamber, and driven by or from any convenient or adjacent prime
moving shaft by any ordinary arrangement of gearing at a slow speed.
The said turning table or frame carries the pendent inclined or revolving
agitators or scrapes, which are made to yield to the inequalities of the
corrugated surfaces; or otherwise the frame of these agitators and
scrapers might be made stationary, and the annular heating floor with
the material to be treated on it might be made to revolve or reciprocate
on like balls or pulleys and grooves actuated in the same or other
equivalent manner to the turning table or frame just described; or in
some cases a false bottom, plain or corrugated, might be made to
revolve or reciprocate in like manner between the stationary bottom and
the agitators or scrapers.
In those cases, when the heating or carrying floor or bottom revolves,
the material may be fed in slowly and regularly through a radial hopper
in the roof, with radial corrugated or vaned rollers working into each
other over one part of the heated annular or corrugated plates, and
regulated at such a width apart as to feed in a constant and regular
quantity of the material in proportion to the differential circumference
of the corrugated surfaces and the speed of the vaned rollers, which
may be driven from the same prime moving shaft or gearing when
actuated as the revolving floor or frame.

page_text: For discharging the material when treated after one or more revolu-
tions round the heating chamber a part of the corrugated or stationary
floor may be hinged and let down by hand or automatically, and a scoop
or other equivalent is provided and let down into the corrugations of the
floor at such an angle that the material would easily and readily rise up
the incline and fall over its upper edge into a receptacle provided to
receive it through the said opening in the movable floor or at the one

page_text: elevation and plan of one of these agitators and scrapers shown to a largo
scale detached from the general arrangement, Figures 1 to 4.
Referring to the modification shown in these Figures 1 to 6, on
Sheet 1, A is the close oven or heating vessel or chamber, into which
the material to be treated is placed, and this chamber is made by these
improvements in the form of a large annular cylindrical vessel with its
heating bottom A' formed of large annular angled or V shaped recesses a
with small flat parts at bottom, and sharp A shaped ridges a¹ alternately,
but these might be made of a corrugated or rounded form instead of
with flat parts, and sharp angles at the bottoms and tops of the grooves
and ridges. The bottom A¹, a, a¹, and the sides A³, A³, of this oven for
the small sizes may be cast in one or in segments, and bolted together
in a usual manner for large sizes, or they may be made of wrought
iron or boiler plates bolted or rivetted together, and have a similarly
formed portable closing-in lid A" fitted gas-tight by an annular recess
in the top edges of the sides A², A³, and ring feathers at the under outer
edges a" of the cover, luted or jointed by fire-clay and screw bolts or
other equivalent jointing at the flanges a", which would stand the heat
and remain tight. The annular close oven A is built in the brick-
work B surrounding the bottom of the smoke stalk or chimney C, and
set on the three narrow annular walls B¹ forming the sides of the three
heating flues B2, B³, B*, formed over the radial heating furnaces D. In
this case five in number of the ordinary construction (but there might
be fewer or more according to the size of the oven and heat required to
be kept up in it) with ash-pit z below each, and a foot plate z¹ over
it at the level of the ground Z in front, where the furnaces D are
charged with coal or other fuel in a usual manner. The furnaces B
are arched over below the two flues B³, B³, but have an opening D¹ up
through this arch into each flue, beginning at the furnace D* on the
left-hand side of Figures 1 and 2, by carrying the radial wall B¹¹, forming
the side wall of the furnace D*, and that of the discharge pit B¹¹¹ of the
oven A, so that the incandescent gases or products of combustion from
each furnace D pass up through these openings D'into and round the two
flues B2, B3, from left to right, as indicated by the red arrows in the
Figures, until they come round to the back of the wall B¹¹ over the pit B",
where they enter the deep narrow annular flue B* close to and right round
the inner side A³ of the oven A until they enter the lower part of the
chimney C by the lateral flue C¹ fitted and controlled by the damper C",
indicated only in dotted lines in Figure 1, but shown better in Figure 2.

page_text: The flames and heated products of combustion while passing round
the two flucs B, B³, acting direct on and up into the angular or inverted
✓ shaped annular grooves ^^ of the whole bottom A¹ of the oven, and
while passing round the flue B' heat the whole of its inner side A³ on
their way to the chimney C. All so as to impart great heat to the oven,
and directly to the material being treated, which lies in the inner
annular recesses a of the bottom of the oven formed by the sides of the
angular heating surface thereof, and which gives great heating surface
as well as convenient means for the regular distribution and stirring or
agitating of the material being treated, as will be herein-after more fully
described.
A thin arch of fire-brick B³ (seen in Figures 1 and 3) is built
over each furnace and set of openings D, D', close up to the bottom A'
of the oven A to prevent the direct action of the flames from burning
it; or this arch may be continued all round the fluc. Within the
oven A, some little distance above the annular recesses and pro-
jections a, a', a revolving ring frame or turntable E is mounted, so as
to revolve on three (or it might be more) balls e in a groove e¹ formed
on the under side of the outer ring of this frame, and a corresponding
groove e below it at the outer circumference of the bottom A¹. This
frame E, which carries the cleaners and agitators b, Figures 5 and 6, is
turned by a small groove ef in its outer perimeter, and a wire rope es
working therein passed round the actuating pulley F, and reversing and
tightening pulley Fi mounted on the spindles F and F carried in
journal bearings in the close box G, bolted by flanges G₁ all round it to
one side of the outer circumference A³ of the oven A, and opposite an
opening, through which the wire rope e³ passes in actuating the turning
table, so as to enclose the driving pulleys and gear, and prevent the
escape of the gases or inflow of air to or from the oven. The upper end
of the first motion shaft A" is carried up through a stuffing box on the
upper side of the box G, and actuated at any suitable slow speed by
the pulley F, and a belt passed over it from any adjacent prime
moving shaft and pulley. The spindle F2 of the pulley F' is carried in
the free ends of a two-armed oscillating lever F³ within the box G, so
that a rod flinked to one arm of the lever F³ passes out through a
'stuffing box G" in one end of the box, and has a chain ƒ¹ or other
equivalent linked to it, and passed up over two reversing pulleys ƒ", ƒ²;
carried in standards on the top of the box G, and has a heavy weight f³

page_text: hung to its free end, all so as to tighten the wire rope e³ to the tension
required to actuate the turning frame E, the mere slacking of the
tension would thus at any time stop the action of the turning table E.
This turning table E, which is shown in transverse and longitudinal
section in Figures 1 and 4, and partly in plan in red lines in Figure 2,
is made open in the centre by radial arms E¹, connecting the two side
rings, which project up sufficiently high to have one, two, three, or more
sets of radial rods E", E², carried in and passed across the open space
in the frame E over the bottom A' of the oven, so as to carry the eys
or oscillating ends 6* of the arms 6 of the agitators and cleaners b¹, 6¹¹,
exactly over the annular grooves or channels a of the bottom A³,
preferably over the alternate grooves on the alternate spindles or
rods E", E³, so as to oscillate freely on them with short pieces of hollow
pipe E³ or other equivalent between the eyes 6* to retain these in their
proper position. Each set of these scrapers and cleaners are shown in
Figure 2 as mounted on five spindles, but there may be fewer or more
of these spindles in the set, according to the nature of the material
being treated; and as seen particularly in Figures 4, 5, and 6, each
arm 6 has a cleaning and agitating arm 6' in the centre, which acts on
the flat part at the bottom of each groove, so as to scrape it and agitate
the material resting on it, and has two kneed curved scrapers 6¹¹ bolted
to it at 6, which act on the angled sides of the groove a, and scrape
them and turn over the material lying in the groove as the carrying
frame E is turned from left to right in Figure 2, as indicated by the
black arrows on it and on the wire rope e³.
The material to be treated is fed in at the top of the hopper A11 from
any ordinary supply shoot, bin, or elevators, so that the sharp grooved
or toothed conical rollers 1 and 2 supply or feed in the material in a
uniform stream over the grooved surface of the oven, proportional to its
area, just in advance of the outlet discharge duct A" in the bottom A',
and in proportion to the speed at which the feeding rollers are driven,
the first roller, 1, of which is actuated direct by the bevel wheels 3 and 4
keyed on the first motion shaft, and on the spindle of this roller, which
is geared to the other roller by the spur wheels 5, keyed on their spindles
carried in bush bearings in the side frames of the hopper A, those of
the roller 2 being movable by pinching screws at 2¹ to give more or less
distance between the rollers and feed or supply of the material.
•
•
1
One or more large pipes A are tightly jointed to the upper part of the

page_text: cover A" for leading off or withdrawing the vapours and gases as they
are evolved from the material being treated within the new or improved
oven or retort A, and a man-hole door A' is formed or fitted in a usual
manner for getting into it for the cleaning, fixing, and repairing of the
scraping and distributing mechanism E, E¹, E", and b, b¹, b¹¹. When
the shale or other material is fed into the oven A, as described, it is
drawn and distributed round in the grooves a by one, two, or more
revolutions of the frame E, E', and the scrapers and distributors
b, b¹, b, until all the vapours and gases are evolved, or the material
thoroughly dried, calcined, or treated as required, when the door A™ is
then opened on its hinged spindle A* at one side of the bottom A² by a
handle A on one end outside the building B, when the residuary or
treated material is then scraped or discharged into the receiving pit Bu
below this door, as before stated and shown in Figures 2 and 3, the
door A being fixed in either its open or closed position to or by the
fixing quadrant H, or other equivalent. The pit B being furnished
,with the closing-in damper B to be kept close when the door A¹ is
open to prevent cold air entering the close oven A or the draught
flue B, and only opened at intervals to withdraw and remove the dis-
charged material; or this material might be removed regularly and
discharged by screw or chain bucket elevators through close ducts
which would not admit air, as flour and granular substances are
removed in grinding mills.
->>
Referring to Sheet 2 of the accompanying Drawings, Figures 7 and 8
are a sectional elevation and a plan in section respectively taken on the
irregular lines 5 5 and 6 6 each on the other of a somewhat
different modification or construction and arrangement of some of the
parts of my said new or improved ovens, kilns, retorts, or furnaces from
that shown on Sheet 1. The general form and diposition or arrange-
ment of the main parts, namely, the heating oven A, brickwork B, B,
flue, chimney, and furnaces B', B², B³, B, C, and D, D', and many
of the minor parts shown in these Figures 7 and 8, are the same as in
Figures 1 to 5 on Sheet 1, and it will be unnecessary to describe them
further than to say that the parts are all indicated by the same reference
letters, and so far the same description applies; it is therefore only
necessary to indicate the differences in this modification from that shown
in Figure 1.

page_text: bottom A¹ of the oven A is made loose, and supported separate from
the body A2, A3, A", of the oven, and mounted so as to be reciprocated
to and fro with one of its under middle grooves a* on or over five
rollers carried in bearings in the cast-iron beams or blocks I securd
on the walls B¹, B¹, B', above the flues B², B³. The reciprocating motion
of the bottom A' is effected by an arm I bolted to it projecting through
into the close box G through a slot in the side A² of the oven A below
that through which the wire rope e³ works, as in the former modification,
to actuate the revolving frame E of the distributing scrapers b, b¹, b¹¹.
The inner end of the arm I' is jointed to the free end of the connecting
rod I", having its other end connected to the pin of a crank I² on the
lower end of a short vertical spindle J, carried in the bearing bracket
and stuffing box bush bearing J¹, J", in the box G, vertically below the
horizontal first motion shaft K in this modification, and which by the
mitre wheels J, J³, actuate the said crank shaft J, so as each revolution
to reciprocate the bottom A¹ of the oven A to and fro on its antifriction
rollers i, all as before stated. The vertical moving shaft F" in this case
derives its slow motion through a screw wheel k on its upper end
gearing into a worm or screw k¹ on the first motion shaft K, which is
carried horizontally in bearing brackets K' on the top of the close box G,
and driven by the fast and loose pulleys K" at one end by a belt passed
over them from a pulley on any adjacent prime moving shaft, not shown
in the Drawings, while a mitre wheel 3 on the other end of the shaft K
gears into a corresponding wheel 4 on the spindle of the first motion
feeding roller 1, so as to actuate the other movable feeding roller 2, as
in the first modification.
As the bottom A' in this arrangement reciprocates the revolving
frame E, E', of the agitators is fitted to turn in shallow grooves e' on
the under face of its side rings Ẹ on six (or it might be other number
of) antifriction rollers e revolving on fixed studs e", three secured
through each side A³, A³, of the oven A.
As the bottom A¹ reciprocates in this arrangement, Figures 7 and 8,
the discharge door A, A, is hinged to the lower throat of a short
discharge hopper or mouth-piece A*, shown only in red lines in these
Figures, jointed to the bottom flanges of the sides A², A³, of the oven A,
and carried on the walls B' as close up to an opening in the bottom A¹
as possible to prevent the escape of gas, or the ingress of air or smoke
from the flues B³, B³, or the pit B", into which the residue of the

page_text: material being treated is discharged through the said duct A* and
door A¹¹¹, controlled by the lever and quadrant A* and A³ outside the
building B, all otherwise as described in reference to the arrangement
on Sheet 1.
The material to be treated is led into the hopper A¹¹ and feeding
rollers 1 and 2, so as to fall in a regular stream across the bottom A' on
the advance side of the discharge hole and mouth A*, where as the sets
of scrapers and distributors b, b¹, b¹¹, come slowly round they spread and
carry a portion of the material over and round the whole furrowed or
corrugated surface of the bottom A³, each revolution of the frame E, E¹,
carrying them, and deliver the same into the discharge hopper A* all
while the bottom A' is being reciprocated by the crank and shaft I², J,
so as to thoroughly agitate the material as it is being distributed and
treated. The speed of this frame and distributors E, E', and 6, 6¹, b¹¹,
are regulated to suit the particular material being treated, so as to carry
round and discharge it only after the drying, baking, caloining, or dis-
tillation has been continued to the full extent desired.
Although the annular, channelled, or corrugated bottom A' of the
oven A has only been described and shown in the accompanying
Drawings as stationary and reciprocated, it is to be understood that it
may be made to revolve at a slow speed in the same manner as and in
the same or in a contrary direction to the frame E carrying the scrapers
and agitators, the latter of which might be stationary when the bottom
thus revolves; or the frame E may be made to reciprocate in the same
manner as the bottom A¹ (as in Figures 7 and 8), which in this case
may either be stationary or revolving, and an inclined scraper might be
used near the opening A* in the bottom A' for lifting and delivering the
treated material over it into the discharge hopper A*; or when the
bottom A¹ does not revolve a delivering scraper might be hinged in
front of the revolving frame E, E¹, for being lowered at intervals when
the material is ready for removal, so as to scrape or deliver the material
into the said hopper A*; and although only blade scrapers or agitators.
have been shown and described as carried round by the revolving
frame E, E', it is to be understood that short chains with projections
out from them might be carried round, so as to trail over and scrape
the surfaces of the annular channels, and agitate the material within
these.
د

page_text: When the material to be treated is in a liquid form, such as soda lye
or sewage matter, or other waste or discharge liquids from paper pulp
and fibre works, and other manufactories, the centre of the brickwork
where the chimney is shown may be constructed with a dome-shaped
vacuum boiler for evaporating down the liquid previous to being placed
in the calcining oven A. In this case the chimney would be built
outside the brickwork B, with the exit flue and damper C¹, C", on the
outside instead of the inside of the oven, for the escape
having heated the vacuum boiler.
of the gases after
Having now described and particularly ascertained the nature of my
said Invention, and the manner of performing the same, I would observe
in conclusion that I do not restrict myself to the particular construction
or use of the whole of the parts of circular ovens or furnaces which I
have had occasion to describe and delineate; neither on the other hand
do I desire to claim the mere making of ovens, kilns, or furnaces
circular, nor the whole of the details thereof by themselves; but what I
consider novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,-
First. The general construction of ovens or kilns with their furnaces,
fittings, and gearing, all substantially in the manner and for the purposes
herein-before described in reference to and shown in the two arrange-
ments on the accompanying Sheets of Drawings, or any mere modification
thereof.
Second. The construction of ovens, kilns, or close heating chambers
with annular, channelled, or corrugated bottoms or floors, either
stationary, revolving, or reciprocating, substantially as herein described
in reference to and shown in the accompanying Drawings, or any mere
modification thereof.
Third. The arrangement of radial furnaces and annular flues above
them for heating the bottoms of circular or annular ovens, kilns, or close
heating chambers, substantially as herein-before described in reference
to and shown in the accompanying Drawings.
Fourth. The construction of annular ovens, kilns, or close heating
chambers with revolving frames of scrapers, agitators, or distributors for
acting on the surface of the floors thereof and amongst the material
thereon, all substantially as herein described in reference to and

page_text: shown in the accompanying Drawings, or any mere modification
thereof.
Fifth. The construction and use of conical rollers, preferably corrugated
longitudinally, for the feeding in of the material into annular or circular
ovens, kilns, or close heating chambers in a regular manner, all sub-
stantially as herein described in reference to and shown in the accom-
panying Drawings, or any mere modification thereof.
In witness whereof, I, the said Robert James Wood, have here-
unto set my hand and seal, this Second day of December, in
the year of our Lord One thousand eight hundred and seventy-
five.
Witness,
W. R. M. THOMSON,
Patent Agent,
Glasgow.
ROBERT J. WOOD. (L.S.)