IMPROVEMENTS IN FURNACES OR APPARATUS FOR THE MANUFACTURE OF ALKALIES AND FOR OTHER PURPOSES
Year: 1871

page_text: LETTERS PATENT to William Holland Furlonge, of 4, Oxford Road,
Hammersmith, in the County of Middlesex, Gentleman, and James
Dixon Churchill, of 12, Saint Thomas's Road, Holloway, in the same
County, Engineer, for the Invention of "IMPROVEMENTS IN FURNACES
OR APPARATUS FOR THE MANUFACTURE OF ALKALIES AND FOR OTHER PURPOSES,"
caled the 30th June 1871, and dated the 9th January 1871.
PROVISIONAL SPECIFICATION left by the said William Holland
Furlonge and James Dixon Churchill at the Office of the Commis-
sioners of Patents, with their, Petition, on the 9th January 1871.
We, WILLIAM HOLLAND FURLONGE, of 4, Oxford Road, Hammer-
smith, in the County of Middlesex, Gentleman, and JAMES DIXON
CHURCHILL, of 12, Saint Thomas's Road, Holloway, in the same County,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FURNACES OR APPARATUS FOR THE MANUFACTURE OF ALKALIES
AND FOR OTHER PURPOSES," to be as follows:-
This Invention is applicable to furnaces or apparatus for the manu-
facture of alkalies, the preparation and treatment of other chemical
materials or compounds, the manufacture of iron, steel, and, other,

page_text: metals, and for other purposes requiring an intense and equable heat.
It relates to furnaces or apparatus of that class in which a bed or
receptacle for containing the materials under treatment is arranged to
revolve by means of any suitable machinery.
In constructing furnaces of this kind according to our Invention the
bed or receptacle for containing the materials under treatment is com-
posed of an annular trough or vessel, lined with fire-brick or other
refractory material, and arranged to revolve on pullies or antifriction
rollers within an annular space or chamber bounded by a circular wall
of brick, masonry, or iron, and situated around a central column or
core which forms the foundation for a suitable crane, or apparatus for
lifting and lowering the covers and other operations connected with
the manipulation of the furnace. The annular space containing the
revolving bed or receptacle is covered by means of a segmental or other
roof supported by the central column and circular wall, by preference
upon suitable metal plates or frames placed thereon. A reverberatory
furnace or fire-place (or furnaces, or fire-places) is (or are) situated at
the side of the annular chamber, so that the revolving bed or recep-
tacle forms the bottom and sides, and the segmental roof the top of an
annular fluc, on to whose bed or rather the materials therein contained,
the flame and intensely heated products of combustion from the furnace
or fire-place are reverberated or caused to impinge.
In carrying out our Invention we in some cases combine apparatus for
burning liquid or powdered fuel, or coal gas, with the arrangement of
revolving annular bed or receptacle, and reverberatory furnace already
described. The exit for the products of combustion from the annular
flue may be situated at the opposite side to the furnace or fire-place, so
that the flame and, heated products of combustion on entering will be
split up or divided into two streams travelling in opposite directions
along the annular flue, meeting and leaving together thro' a common
exit opening, but we do not confine ourselves to this arrangement..
In constructing furnaces according to our Invention for purposes
requiring a less intense heat we arrange the fire-place and exit, side. by
side, or at any suitable position of the circumference, so that the heated
products of combustion travel in a single stream through a part of or the
entire length of the annular flue. Portions of the annular, roof may
be removed for the introduction of the materials to be treated in the
annular bed or receptacle, the discharging of the finished products and

page_text: for the insertion of fixed or moveable instruments which we provide for
the purposes of mixing, turning over, and otherwise manipulating the
substances under treatment, and when these substances are of a kind.
requiring to be supplied with oxygen or other gases whilst under
treatment we admit and combine such gases with the materials under
treatment by suitable channels or passages provided for that purpose
in the mixing or manipulating instruments. The finished products if
in a liquid state may be removed from the annular bed or receptacle
by running in the ordinary manner, for which purpose we make the bed
plate or supports of the pullies or antifriction rollers within the annular
chamber adjustable so that they may when requisite be somewhat
lowered, and thus slightly incline the annular bed or receptacle, but for
withdrawing substances of a pasty or semi-liquid consistency, we prefer
to employ an apparatus somewhat resembling an ordinary dredging
machine of simple construction having scoops or buckets carried upon
endless chains and emptying into a suitable spout or trough for con-
ducting the materials away as required. Or otherwise in lieu of the
means just described, we may in some cases employ an apparatus
consisting of a suitable framing arranged to rest upon the central
column and circular wall, and carrying a horizontal rotating shaft,
provided at one end with a slotted tube or hollow boss furnished with
scoops, which when the apparatus is placed in position for being used
are situated partially within the annular bed or receptacle. These
scoops carry up from the annular bed the finished materials or products,
and discharge them into the rotating tube or hollow boss from whence
they are conducted along a suitable spout or channel away as required
by means of a screw arranged for that purpose around the rotating
shaft. When the materials to be removed from the annular bed or
receptacle are in a powdery or non-cohesive condition, such for instance
as roasted ores, we may adapt to the annular bed or receptacle an
arrangement of apparatus for withdrawing the materials by means of a
steam induced current or currents somewhat similar to those employed
for removing ashes from the ash-pits of marine steam boilers. Provision
is made for preventing the escape of the heated products of combustion,
and the access of cold air between the sides and roof or covering of the
revolving bed or receptacle, and arrangements are provided for cooling
the antifriction pullies or rollers and their bearings when requisite, for
which purpose we prefer to employ a current or currents of cold air,
and to utilize the same when heated in maintaining the combustion in

page_text: the furnace or furnaces, we do not. however limit ourselves to this mode..
of cooling the antifriction pullies or rollers and their bearings. We in
some cases supply and work the furnace with compressed air..
:
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Holland Furlonge and James Dixon
Churchill in the Great Seal Patent Office on the 8th July 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
HOLLAND FURLONGE, of 4, Oxford Road, Hammersmith, in the County
of Middlesex, Gentleman, and JAMES DIXON CHURCHILL, of 12, Saint
Thomas's Road, Holloway, in the same County, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Ninth day of January, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors; give
and grant unto us, the said William Holland Furlonge and James
Dixon Churchill, Her special licence that we, the said William Holland
Furlonge and James Dixon Churchill, our exccutors, administrators, and
assigns, or such others as we, the said William Holland Furlonge and
James Dixon Churchill, our executors, administrators, or 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 66
IMPROVEMENTS IN FURNACES OR APPARATUS FOR THE MANU-
FACTURE OF ALKALIES AND FOR OTHER PURPOSES," upon the condition (amongst
others) that we, the said William Holland Furlonge and James Dixon
Churchill, our exccutors or administrators, by an instrument in writing
under our, 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 we, the said William Holland Furlonge and
James Dixon Churchill, do hereby declare the nature of the said Inven-
tion, and in what manner the same is to be performed, to be particu-

page_text: .
|larly described and ascertained in and by the following statement,
thereof, reference being had to the accompanying Sheets of Drawings;
which form portions of this Specification in which the same letters of
reference are used to denote equivalent parts in all the views.
This Invention is applicable to furnaces or apparatus for the manu-
facture of alkalies, the preparation and treatment of other chemical
materials or compounds, the manufacture of iron and steel, and other
metals and for other purposes requiring an intense and equable heat. It
relates to furnaces or apparatus of that class in which a bed or receptacle
for containing the materials under treatment is arranged to revolve by
means of any suitable machinery..
:
In constructing: furnaces of this kind according to our Invention
the bed or receptacle for containing the materials under treatment is
composed of an annular trough or vessel lined with fire-brick or other
refractory material, and arranged to revolve on pullies or antifriction
rollers within an. annular space or chamber bounded by a circular wall
of brick, masonry, or iron, and situated around a central column or
core which forms the foundation. for a suitable crane or apparatus for
lifting, and lowering the covers and other operations connected with the
manipulation. of the furnace, the annular space containing the revolving
bed or receptacle is covered by means of a segmental or other roof
supported by the central column and circular wall by preference upon.
suitable metal plates or frames placed thercon.. A reverberatory furnace
or, fire-place (or furnaces or fire-places) is (or are) situated at the side
of the annular chamber so that the revolving bed or receptacle forms the
bottom, and sides, and the segmental roof, the top of an annular flue on
to whose bed or rather the materials thercin contained; the flame and
intensely heated. products. of combustion from the furnace or fire-place
are reverberated or caused to impinge.
In carrying out our Invention we in some cases combine apparatus for
burning liquid or powdered fuel or coal gas with the arrangement of
revolving annular bed or receptacle and reverberatory furnace already
described. The exit for the products of combustion from the annular flue
may be situated at the opposite side of the furnace or fire-place so that
the flame and heated products of combustion on entering will be split
up or divided into two streams travelling in opposite directions along
the annular flue, meeting and leaving together through a common exit
opening but we do not confine ourselves to this arrangement.

page_text: In constructing furnaces according to our Invention for purposes
requiring a less intense heat we arrange the fire-place and exit side
by side, or at any suitable position of the circumference so that the
heated products of combustion travel in a single stream through a part
of or the entire length of the annular flue, portions of the annular roof
inay be removed for the introduction of the materials to be treated in
the annular bed or receptacle, the discharging of the finished products,
and for the insertion of fixed or moveable instruments which we provide
for the purposes of mixing, turning over, and otherwise manipulating
the substances under treatment, and when these substances are of a kind
requiring to be supplied with oxygen or other gases whilst under
treatment we admit and combine such gases with the materials under
treatment by suitable channels or passages provided for that purpose
in the mixing or manipulating instruments. The finished products
if in a liquid state may be removed from the annular bed or receptacle
by running in the ordinary manner, for which purpose we make the
bed plate or supports of the pullies or antifriction rollers within the
annular chamber adjustable so that they may when required be some-
what lowered and thus slightly incline the annular bed or receptacle,
but for withdrawing substances of a pasty or semi-liquid consistency we
prefer to employ an apparatus somewhat resembling an ordinary dredging
machine of simple construction, having scoops or buckets carried upon
endless chains and emptying into a suitable spout or trough for con-
ducting the materials away as required or otherwise in lieu of the means
just described we may in some cases employ an apparatus consisting of
a suitable framing arranged to rest upon a central column and circular
wall and carrying a horizontal rotating shaft provided at one end with
a slotted tube or hollow boss furnished with scoops, which when the
apparatus is placed in position for being used are situated partially
within the annular bed or receptacle. These scoops carry up from the
annular bed the finished materials or products and discharge them
into the rotating tube or hollow boss, from whence they are conducted
along a suitable spout or channel away as required by means of a screw.
arranged for that purpose around the rotating shaft.. When the materials
to be removed from the annular bed or receptacle are in a powdery or
non-cohesive condition, such for instance as roasted ores, we may adapt
to the annular bed or receptacle an arrangement of apparatus for
withdrawing the materials by means of a steam, induced current or
currents somewhat similar to those employed for removing ashes from
1

page_text: ash-pits of marine steam boilers.. Provision is made for preventing, the
cscape of the heated products of combustion and the access of cold
air between the sides and roof or covering of the revolving bed or
receptacle, and arrangements are provided for cooling the antifriction.
pullies or rollers and their bearings when requisite, for which. purpose
we prefer to employ a current or currents of cold air and to utilize
the same when heated. in maintaining the combustion in the furnace
or furnaces..
We do not however limit ourselves to this mode of cooling the anti-
friction pullies or rollers and their bearings. We in some cases supply
and work. the furnace with compressed air.
Such being, the nature of our Invention we now proceed to describe
more particularly the manner of carrying the same into practical
effect.
Fig. 1, on Sheet 1, of the accompanying Drawings represents in
vertical section through the line A, B, of Fig. 2, a furnance constructed
according to our Invention; Fig. 2, a plan of the same partly in section
through the line C, D, of Fig. 1; Fig. 3, a section through the line
E, F, of Fig. 2, shewing also one of the arrangements of the discharging.
apparatus hercin-before described; Fig. 4 an elevation of part of the
furnace with the discharging apparatus in end elevation; Fig. 5, a plan
of the same, and Fig. 6, a transverse section of the slotted boss and
scoops of the discharging apparatus; a, is the annular trough or recep--
tacl lined with fire-brick a¹, and arranged to revolve on antifriction.
rolles 6 within the annular space or chamber c, bounded by the circular
brick wall c¹ situated around the central core c³, which in this arrange-
men forms the foundation for the crane. The crane is not shewn in the
Dravings as it may obviously be of any well-known or other construction
suitable for lifting and lowering the covers and for other operations
connected with the working of the furnace. The annular space or
chamber c is covered by the brick roof supported by the central core
an the circular wall c', the edges of the roof resting upon the metal
plate c, c, which are formed with vertical ledges and placed securely
upon the core and wall c¹ for the reception of the roof as shewn.
The rough a may be made either of sheets of wrought iron rivetted
together, or of cast iron made in sections with suitable flanges and
boltd together. It is guided when travelling within the annular.
Y
с

page_text: chamber c by a number of antifriction. rollers of which one is shown
at b¹, carried by iron standards c³, c, built in with and forming portions
of the wall c¹ and core c². These standards assist materially in sup-
porting the roof c³. The reverberatory fire-place d is situated at the
side of the annular chamber c, and it will thus be seen that by the use
of the revolving annular trough or receptacle a, a, in combination with
the stationary annular roof c³, according to our Invention an annular
flue is formed of which the revolving receptacle a, a¹, forms the bottom
and sides, and the roof c³ constitutes the top, and that the bed of
this annular flue so formed contains the materials on to which the flame
and intensely heated products of combustion from the fire-place are
reverberated or caused to impinge. The exit for the products of com-
bustion is at d', so that the flame and heated products of combustion on
entering are split up or divided into two streams travelling in opposite.
directions along the annular flue as indicated by the arrows, and
meeting and leaving together as shown.
Portions of the annular roof c³ are made removeable to form openings
(one of which is shewn a c³), for the introduction of the materials to
be treated in the annular bed or receptacle, the discharging of the
finished products, and for the insertion of the instruments. hcrcir-after
described for mixing, turning over, and otherwise manipulating the
substances under treatment; the arrangements for withdrawing the
materials from the annular receptacle a after treatment, theren will
naturally vary according to the nature of the substances to be removed
as herein-before stated. The apparatus shewn in the present case is a
designed more particularly for withdrawing substances of a pasty or
semi-liquid consistency and consists of a framing e which rests won
the central core e² and circular wall c¹ and carries a horizontal shat e¹,
provided at one end with the slotted tube or hollow boss e² which is
furnished with scoops e³ situated partially within the annular be or
receptacle as shewn. These scoops e³ carry up from the annular bed
the finished materials or products and discharge them into the rotating
slotted tube or hollow boss e from whence they are conducted aong
the spout or channel e¹ away as required by means of the scree
arranged for that purpose around the shaft e¹. The annular recepacle 3
a may be rotated by means of a pinion or pinions gearing into a ack
or racks attached by preference to the inner or outer periphery, oto
the inner and outer peripheries of the receptacle, or to its botton, or
1

page_text: in lieu of the pinions and racks, wormed racks and screws may be
used.
!
These arrangements are not shewn in the Drawings because they
are well-known mechanical expedients whose construction and appli-
cation to the purpose will be readily understood. The escape of the
heated products of combustion and the access of cold air between the
sides of the receptacle a and the roof c³ are prevented by an ordinary
luting, which may consist of sand or other solid material, or in some
cases, as when treating materials evolving volatile or gaseous products,
a liquid luting may be employed. The luting is contained within the
annular gutters f, into which. suitable flanges or feathers f¹ dip as
shown.
Fig. 7 (Sheet 2) represents to an enlarged scale an arrangement
in which the construction of the roof c³ and its wall plates c', c³, is
somewhat modified from the arrangement already described, and the
withdrawing apparatus (shewn in side elevation at Fig. 8) is made
with scoops or brackets es carried upon endless chains e as herein-
before described; the necessary motion being imparted to the apparatus
through the shaft e'; g, g, are standards which may be secured by bolts
and are provided for holding the mixing tools and other apparatus as
herein-after described.
Fig. 9 is a front view partly in elevation and partly in section of
the instrument which we provide for the purposes of mixing, turning
over, and otherwise manipulating the substances under treatment in the
annular receptacle a. Fig. 10 is a section of the same through the
line G, H, of Fig. 9, and Fig. 11 is a section through the line I, J.
This instrument when intended to be used for the treatment of
materials at comparatively low temperatures, as for instance the mixing
of orcs during roasting, chlorinating, and so forth, may be made of cast
iron. It is formed with a flange for enabling it to be attached to
a suitable pipe, whereby steam, air, or gases can be supplied to the
channels or passages in the instrument, and from thence admitted
to and combined with the materials under treatment through suitable
apertures formed in the back ² of the instrument.
Figs. 12 and 13 shew the apparatus we prefer to employ for carrying
and working the mixing instrument. This apparatus consists of a
face plate y, similar to the tool holder of a planing machine, to which

page_text: the instrument is attached by bolts and nuts, and which plate is capable
of being moved vertically upon the slides g² of the standard g by means
of the gearing g³ for the purpose of lowering, the instrument into and
withdrawing it from the annular receptacle a as required. This
arrangement of mixing or manipulating instrument and holding. appa-
ratus may be used in connexion with any of the forms of our furnaces
herein described, as may also the instruments and holding, apparatus
constructed as herein-after severally specified.
Fig. 14 (Sheet 3) represents in transverse section part of a furnace as
constructed according to our Invention, in combination with apparatus
for burning coal gas; Fig. 15 a plan, partly in section, of portions of the
furnace, the part K, L, shewing the plan on top,, the part M, N, section
through the line M, N, of Fig. 14, and the parts O, P, and Q, R, are
sections through the corresponding lines of that Figure; Fig. 16 sections
of the arrangements for protecting the braces or ties uniting the sides of
the trough or receptacle a; Fig. 17, an end elevation of one of the sup-
porting pullies with its plummer block; and Fig. 18, a transverse section
of the roof c³, as constructed when the furnace is intended to be worked
with an internal pressure exceeding that of the external atmosphere..
In this arrangement the entire furnace is built upon an amular iron:
foundation plate i on to which are bolted the wall, standards and the
core standards c carrying the wall plates c, c₁, for supporting the
roof c³. The coal gas is generated in a separate generating apparatus
(which may be of the usual well-known construction) and is conveyed
from such generating apparatus by a pipe or tube & into the lower part
of the annular flue / which runs beneath the annular trough or receptacle
whose bottom is constructed along its central portion of firc-clay bricks
or slabs in order that the heat generated by the combustion of the coal
gas within the flue is transmitted to the materials under treatment
in the annular trough or receptacle. The flue is is made of fire-brick
and the upper edges of its walls are formed with gutters f" containing
luting, into which feathers 3 dip to prevent leakage. The products
of combustion of the gas after passing along the flue beneath the
bottom of the annular trough pass as shewn into and through the brick
fluc (Fig. 15), whereby they are conducted through the roof and
reverberated or caused to impinge upon the materials under treatment
in the annular trough or receptacle, the products of combustion passing
along the annular fluc formed by the receptacle and roof as described

page_text: and away by the opening d' in the manner specified with reference to
the form of furnace shewn on Sheet 1. The sides of the annular trough
are united and held together by the wrought or cast-iron braces, tie rods,
or plates m passing through the fire-brick bottom, but we do not propose
to employ these ties in furnaces working at very high temperatures
which would affect their stability. The ties m arc surrounded by
annular or other spaces, through which air is allowed to circulate for
the purpose of cooling the ties.
When the furnace is intended to be worked under pressure as
described, the spaces between the standard c and those between the
standards care to be filled up with iron plates, so as to form iron walls
enclosing the annular. space within which the annular trough travels,
and the fire-clay roof c³ is attached by bolts to an external iron arch or
plate bolted to the wall plates c', c³, as shown. The arch c³ is formed
with an aperture for the insertion of the manipulating instruments and
other purposes, which aperture is provided with a cover c¹ for closing
it when necessary.
Fig. 19 (Sheet 4) shews a modified arrangement of the apparatus for
burning coal gas in combination with the revolving annular bed or
receptacle and stationary roof. In this case the ties mare dispensed
with, the bottom of the annular receptacle being made either in the
form of a slab, as shewn to the left of the centre of the figure, or with
its under part curved to reduce its thickness as much as possible without
seriously impairing its strength as shewn to the right of the figure and
the positions of the luting gutters f and feathers f³ slightly altered
as will be readily understood from the Drawing which needs no further
description.
Fig. 20 represents a modification in which the annular receptacle a
is constructed with deeper sides carrying brick ledges a³, which support
the bottom of the annular receptacle and form the sides of the annular
gas fluc . The standards c³, c', and the adjustable plummer blocks of
the pullies (shewn separately at Figs. 21) are firmly held in their
proper relative positions by attachment to the annular foundation plate i
which rests upon a suitable concrete foundation not shewn in the Drawing.
Each of the adjustable plummer blocks is composed of a central bearing
part containing an oil box ³ and formed with end slides 6* fitting
into corresponding grooves in stationary upright guides
foundation plate i.
bolted to the

page_text: .
On Sheets 5 and 6 we have illustrated an arrangement of furnace
in which provision is made for withdrawing the materials from. the
revolving annular receptacle after treatment therein through an open-
ing or openings in the side of the receptacle, Fig. 22 being a front
clevation of the outer wall and side of the receptacle showing the
opening through which the materials are withdrawn; Fig. 23, a section
through the line S, T, of Fig. 25; Fig. 24, a section through the. line
U, V, of Fig. 25; and Fig. 25, a section through the line W,X,: of
Fig. 24. The revolving annular receptacle is made deeper than in the
previously described arrangements, and the roof c³ dips into the receptacle
and is bolted to and held by an annular plate or plates o". For the
purpose of removing the materials from the receptacle an iron plate
carried by the apparatus herein-before described for holding the manipu-
lating instruments is to be inserted through the opening in the roof at j..
so as to dip into the materials to be removed. As the receptacle revolves
the materials are brought in contact with and caused to accumulate
against the iron plate until the discharging door a² comes round to this
position, whereupon the door a² is opened and the materials are with-
drawn. A recess is formed in the roof at as to allow room for the
materials to accumulate as described. The flues are to be provided with
luting as in the previous arrangements.
Fig. 26 (Sheet 7) is a sectional plan of the furnace shown partly at
Fig. 20 on Sheet 4; Fig. 27 (Sheet 8) shews in section the connection
between the flue and the revolving annular receptacle in said furnace ;.
and Fig. 28 is a plan in section through the line Y, Z, of Fig. 27.
· The instrument employed in connexion with the revolving annular
receptacle for the purpose of effecting a complete mechanical mixture
of the materials therein instead of being constructed as herein-before
described may consist of a forked or pronged tool somewhat resembling
a hay rake, having a cast or wrought-iron back in which are inserted
a series of prongs or teeth set vertically or at an angle with a handle
or shaft rising vertically from the centre of the back of the rake, by
means of which the tool may be made to revolve within the annular
receptacle, or a vertical shaft may be employed furnish with oblique
radial vanes and caused to revolve within the annular receptacle; or an
apparatus similar to a garden roller may be arranged to rest upon the
bottom of the annular receptacle. or may be suspended: therein so as to
operate upon the materials, or the manipulating instrument may.consist

page_text: of a radial arm having one or more attachments similar in form to those
of a ploughshare. These several instruments (the roller arrangement
excepted) may be formed with passages for the purpose of admitting
air, steam, or gases to the materials under treatment, as in the stirrup
like instrument herein-before described and illustrated, or such passages
may be used for the circulation of water to keep the instruments cool.
The instruments are to be held and operated by the apparatus carried by
the standards g herein-before described. When the revolving annular
receptacle is intended for the evaporation of liquids and such like
purposes the interior lining may in some cases be dispensed with.
And having now fully described and ascertained the nature of our said
Invention for "Improvements in Furnaces or Apparatus for the Manu-
facture of Alkalies and for other Purposes," and in what manner the same
is to be or may be performed or carried into practical effect we desire to
point out that we do not restrict ourselves to the precise forms or details
we have shewn in the Drawings and herein-before described for the
purpose of illustrating the use of our Invention, as such forms and details
may obviously be more or less varied to meet the requirements of parti-
cular applications without departing from the distinctive character of
our Invention. We do not claim as of our Invention the making of
furnaces with revolving or rotating beds otherwise than when such beds
are made in the form of annular troughs or receptacles and used in
combination with fixed annular roofs or covers, nor do we lay any claim
to novelty in respect of the separate mechanical parts composing our
improved furnaces when such parts are used otherwise than in com-
bination according to and for the purposes of our Invention, in respect of
which what we do claim as being secured to us by the herein-before in
part recited Letters Patent is,―
Firstly. Constructing furnaces with annular beds or receptacles for
containing the materials under treatment, such annular beds or recep-
tacles being arranged to revolve within annular spaces or chambers and
covered by means of stationary roofs so that the revolving beds or
receptacles and the roofs together form annular flues, along which the
heated products of combustion from the fuel employed may pass in
annular directions over the materials under treatment in the revolving
annular beds or receptacles substantially as described.
Secondly. The arrangement in combination of the revolving annular
bed or receptacle, stationary roof, and external furnace or fire-place, so

page_text: 'that the revolving bed or receptacle forms the bottom and sides, and the
roof the top of the annular flue for containing the materials on to which
the heated products of combustion from the fire-place are reverberated
or caused to impinge substantially as described.
Thirdly. The combination with the revolving annular beds or recep-
tacles of arrangements for burning gas and reverberating the products
of combustion therefrom on to the materials under treatment in the
annular beds or receptacles substantially as described.
In witness whereof, we, the said William Holland Furlonge and
James Dixon Churchill, have hereunto set our hands and seals,
this Eighth day of July, in the year of our Lord One thousand
eight hundred and seventy-one.