CERTAIN IMPROVEMENTS IN KILNS FOR BURNING BRICKS, TILES, AND POTTERY, AND IN THE MODE OF UTILIZING THE HEAT GENERATED THEREIN
Year: 1872

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical
Draughtsman, for the Invention of "CERTAIN IMPROVEMENTS IN
KILNS FOR BURNING BRICKS, TILES, AND POTTERY, AND IN THE MODE OF
UTILIZING THE HEAT GENERATED THEREIN."-A communication from
abroad by A. R. Morgan, of the City and State of New York,
United States of America.
:
Sealed the 7th May 1872, and dated the 27th January 1872.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition,
on the 27th January 1872.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN
KILNS FOR BURNING BRICKS, TILES, AND POTTERY, AND IN THE MODE OF UTILIZING
THE HEAT GENERATED THEREIN," to be as follows:-

page_text: The kiln which is the subject of the improvements hercin-after
described is of that class in which the heated àir and products of com-
bustion are introduced to the chambers containing the articles to be
burned at the top and caused to flow downward through the bottom.
It is so arranged that the heat escaping from one compartment in
cooling off after burning is utilized in another for heating the green
bricks or other material before the fire of the furnace is turned on.
Two or more compartments being arranged in a group for convenience
in causing the heat to flow from one furnace to two or more com-
partments, and, in conducting the remaining heats in a burned
compartment to another to aid in drying the green material preparatory
to burning, or the hot air from the cooling compartment may be used
to feed the fire for burning another compartment, thus economizing all
of the heat in a burned compartment. Supposing the kiln to contain
four compartments for burning bricks it is formed of two adjoining
longitudinal chambers built side by side having hollow end and side
walls and hollow arched roofs. These chambers are divided each into
two compartments by means of four furnaces erected and arranged
transversely in the middle of the kiln. In the centre of this group of
furnaces the chimney stack is conveniently placed. The lower part of
the chimney is divided vertically so as to form four distinct flues, which
flues communicate with their respective compartments in which the
bricks are burned. The floor of these compartments is made hollow, and
consists of bricks or tiles laid upon longitudinal or transverse arched
dwarf walls, such bricks or tiles being of suitable dimensions to span the
spaces between the walls. The floor is so laid as to provide a free
passage downwards through the floor for the heat admitted to the
compartment. The space below the floor may connect directly with
one of the flues of the chimney, or a central well may be formed below
the floor to collect the heated air and pass it through a covered passage
to the chimney. The flues of the chimney are furnished with dampers
to regulate the draft of the chimney as desired.
. Each compartment is brought into connection with a respective
furnace by means of an opening near the crown thereof, and through
the dividing wall of each pair of furnaces below the level of the fire-
A
places an opening is made to connect the ash-pit together.
longitudinal passage is also made in this wall to connect the two latteral
openings together; thus the ash-pits of all the four furnaces are brought

page_text: into connection. Dampers are however provided for cutting off the
connection of this ash-pit with each other. The outer end walls of the
compartments where they connect with the arched roof are built with
a rebate to receive the end of the arched roof, and they are left free to
contract and expand without disturbing the roof. The joint may be
filled with loose sand to prevent the in-draft of cold air. By raising the
side and end walls to a level with the arches the top of the kiln may
be utilized for drying a layer of sand, which will also assist in preventing
the radiation of heat. The compartments are entered for the purpose of
stacking the bricks, tiles, or pottery by an opening in the outer end
walls, which opening when the compartment is charged is temporally
walled up; other openings fitted with dampers are also made in these
walls near the crown of the compartments for admitting cold air
thereto. In order to protect the furnace arches from the effects of
the intense heat they are made hollow, and receive air from flues in in
the walls and opening out to the atmosphere. The air in passing through
the hollow brickwork of the arches takes up the heat and passes down
vertical flues, which conduct it to the ash-pit. The air for supplying
combustion therefore enters the furnace in a heated state. These
vertical flues may also connect with the fire-chamber on or about a
level with the fuel, and they may thereby be caused to deliver air on to
the fuel to assist in the combustion of the smoke.
.
Besides the arrangements already described for leading off the hot air
from below the floor of the compartments, an opening may be made
through the inner end walls for conducting the heated air to the adjacent
ash-pit.
The mode. of burning the bricks and thus utilizing the heat is as
follows: One of the compartments being charged with green bricks
a fire is started in the furnace adjacent to it, the heated gases generated
pass into the compartment containing the bricks, and having circulated
among them pass through the floor and through the passages under the
floor to the chimney.
When the bricks have become sufficiently burned and it is necessary
to cool them off, the heat is by the application of the dampers conducted
from the burned compartment back through its furnace and through
the lateral opening in the ash-pit to the other cool furnace, whence it
passes into the adjoining compartment containing green bricks to be
dried. When the next one to be burned is on the same side of the
.

page_text: chimney as that last fixed, but if on the other side of the chimney the
heat is conducted along the transverse passage before mentioned to the
furnace of the charged compartment in the same way. When the com-
partment having the green bricks has been heated up equal to that of
.the one cooling off, the remaining heat in the cooling compartment is to
be utilized to feed the fire, which will then be started in the furnace
of the compartment thus partially heated, and fed with heated air from
the compartment cooling off as long as any heat remains in it. This is
done by admitting cold air to the cooling compartment, or the heat may
be led off to an adjacent drying chamber, or otherwise utilized.
To ensure the equible diffusion of the heat through the charge of
bricks the lower layer may be laid flatwise leaving narrow lines of spaces
between them, and for some distance along these lines commencing from
the inner end wall filling pieces of wood may be inserted, which will
have the effected of checking the draft where the filling occurs, and
inducing the heated air to pass to the other end of the compartment.
As however the heat increases in intensity the wood filling will be
burned up, and the passages for the circulation of the hot air opened.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alfred Vincent Newton in the Great Seal Patent a
Office on, the 22nd July 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent. Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of January, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alfred Vincent Newton, Her special
licence that I, the said Alfred Vincent Newton, my executors, adminis-
trators, and assigns, or such others as I, the said Alfred Vincent Newton,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter

page_text: 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
" CERTAIN IMPROVEMENTS IN KILNS FOR BURNING BRICKS, TILES, AND POTTERY,
AND IN THE MODE OF UTILIZING THE HEAT GENERATED THEREIN," being a com-
munication to me from abroad by A. R. Morgan, of the City and State
of New York, United States of America, upon the condition (amongst
others) that I, the said Alfred Vincent Newton, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alfred Vincent Newton, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing here-
unto annexed, and to the letters and figures marked thereon (that is to
say) —
The kiln to which the improvements herein-after described relate is of
that class in which the heated air and products of combustion are
introduced to the chambers containing the articles to be burned at the
top and caused to flow downward through the bottom. It is so arranged
that the heat escaping from one compartment in cooling off after burning
is utilized in another for heating the green bricks or other material
before the fire of the furnace is turned on, two or more compartments
being arranged in a group for convenience in causing the heat to flow
from one furnace to two or more compartments, and in conducting the
remaining heat in a burned compartment to another to aid in drying the
green material preparatory to burning, or the hot air from the cooling
compartment may be used to feed the fire for burning another compart-
ment, thus economizing all of the heat in a burned compartment.
'
In the Drawings two forms of the improved kiln are shewn. Fig. 1 is
a longitudinal sectional elevation of a kiln with the improvements applied
thereto, the section being taken on the line z, z, of Fig. 2; Fig. 2 is a
horizontal section on the line x, x, of Fig. 1; Fig. 3 is a transverse

page_text: section of Fig. 2 on the line y, y; Fig. 4 is a transverse section of Fig. 2
on the line y', y¹; Figures 5 and 6 are details shewing a damper and
passages for admitting air above the grate when required; Fig. 7 is a
longitudinal section of a modified form of the improved kiln taken in
about the plane indicated by the line.z, z, of Fig. 2, and Fig. 8 is a
horizontal section of the same on the line x, x, of Fig. 7; Fig. 9 is an
clevation of part of a floor, with some bricks upon it, shewing the mode
of equalizing the application of the heat during the first part of the

page_text: The arrangement of the hollow walls and semicircular arches is also
desirable because the walls exposed to the heat and subject to repair and
removal may thereby (as has been demonstrated in practice) be much
thinner than when made solid, for the outer walls not exposed to the
heat and damage thereby remain intact, and protect the inner ones from
the counter action of the atmosphere on them when heated and cooled,
and in the arched form they are best adapted to retain their positions in
expanding and contracting or to resist the effect of such action. The
inner and outer walls are butted together at suitable distances apart
either by continuous or intermittent connections I and hoops or bands K
anchored down in the ground, or in the foundation walls are stretched
over the arches and connected as at L by a swivel or other means by
which they may be tightened to prevent undue expansion of the walls.
The second part of the Invention consists in a device for preventing
the escape of hot air or admission of cold air to the interior at the
joints of the end walls with the arches which are liable to open by the
expanding of the insides of the end walls, and consequent springing
outward of the tops by the heat which swells the insides more than the
outsides, by which they move away from the ends of the side walls
especially at the top. This device consists of a lap joint formed by a
rebate in one part with the other fitting into said rebate, as shewn
at H, and a filling or packing of loose sand. In the case of the top
of the end walls and the arches they are so arranged that this joint
opens to the atmosphere vertically as indicated in Fig. 1, whereby
5 sand placed on the top of the kiln to dry will fall in as the joint
opens and prevent the transmission of air, and it may be allowed to
run down to the joints between the vertical parts and keep them closed
also to a considerable extent. When the walls are cooled down and
the ends spring back again the sand will be forced from the joints to
the interior of the kiln sufficiently to allow of the necessary return of
the end walls. This device is more especially applicable to the joints
between the end walls and arches only.
The third part of the Invention relates to the construction of the
floors of the kiln which for producing the most uniform results in
this mode of applying the heat, should be as open as possible
throughout the whole area to allow the heated air to settle down and
pass off in all parts alike. For this purpose there are built up parallel

page_text: rows of brick walls L', the thickness of the width of one brick with
spaces L between of the same width and having arches or openings of
any kind N between them. On these walls an open floor of bricks O is
laid, it being made alternately with spaces P in each direction of the
same size or nearly so as that of the bricks. In practice the bricks will
lap each other slightly as indicated in Fig. 2, to prevent shifting about.
The arched walls L' are preferably arranged parallel with the longest
diameter of the furnaces and the passages formed by the arches perpen-
dicular to them, but this is not essential, either way provides free passage
below the floor for the air to find its way from all parts to the escape
passage Q, leading into the smoke stack F. It will be seen that this
arrangement of the floor facilitates the application of the heat equally
to the bricks set upon it at the lower part.
The distribution of the heat in the compartments is effected mainly
by the tendency of the heated air admitted at the top to spread laterally
when prevented from escaping upward, which is its natural course, but
in practice it is found to deviate somewhat from this and to spread,
especially when exhausted, from the bottom of the chamber by a
powerful draught, the said deviation being caused by the tendency of the
heated air to favor the most direct course from the passage f¹ where it
enters. When the kiln is filled with green material to the bottom along
the wall D to the escape passage Q, so that the bricks at the outer end
wall of the compartment will sometimes fail of being burned equally
with those in the other part of the kiln. While this tendency may be
modified somewhat by limiting the draught (by closing the dampers) it
cannot be completely overcome thereby, and at the same time maintain
sufficient draught to meet the requirements for proper combustion and
obtaining the requisite degree of heat, especially if the compartments
have considerable length.
The following arrangement is therefore provided to counteract this
tendency, which said arrangement constitutes the fourth part of the

page_text: the laths used in plastering or other like combustible material. This
filling serves temporarily to stop the draught through the spaces between
the bricks above and compel the heat to flow to the outer end of the
compartment during the first part of the burning, and until the green
bricks having the lath strips between them become sufficiently heated to
ignite and burn out. When this has taken place the heat will be free
to descend through the formerly obstructed part and alike do its work
therein, and in the part most distant from where it enters and escapes.
When the said most distant parts has been heated up in this way the
draught will continue through it after the wood strips have been burned
out for a considerable time, because of the greater heat thereat to which
the inflowing heat naturally tends. The distribution of the heat in this
way may be regulated to any practical requirement by varying the
distances of the rows of bricks apart and the size of the strips.
The fifth part of the Invention consists of devices for introducing a
current of external air in a peculiar manner for the purpose of protect-
ing the furnace arches from the effects of the intense heat they are subject
to and to furnish heated air for combustion. This air from without is
admitted to the tops of the arches X through passages or flues beginning
at the bottom of the kiln, the furnaces being closed thereat for prevent-¨
ing the escape of heat through the supply passages, which occurs when
said passages are located so as to receive the air above the arches as
heretofore practised when the furnace doors are opened for supplying
fuel. For this purpose passages or flues y are provided by any suitable
construction of the walls, the said passages leading from the ground on
a level with or below the furnace doors up to the arches X over the
furnaces. The air passing through these passages cools the furnaces
and conveys the heat taken up thereby to the fire, passing down from
said arches to the ash-pits through the passages f.
Instead of employing the flues y openings may be provided through
the outer walls of the kiln admitting the cold air to the spaces a between
the outer and inner walls, to flow thence up over the arches D to the
furnace arches ✗ if preferred to protect the inner walls of the brick
compartments from the heat, and to heat the air more before entering
the fire, but in this case the inner walls should be free from cracks,
which would admit the air directly to the compartments containing the
bricks and injure the same. Heretofore the air bas been admitted to the

page_text: furnaces of a group by chambers and passages below, with controlling
dampers, whereby a most simple and efficient means is provided in con-
nection with the air passages from the furnaces to the compartments and
the passages for admitting air to the compartments for cooling them off,
by which the remaining heat in a burned compartment may be caused
to flow into any other compartment in the group or to the adjoining
dry house, or for utilizing it to dry and heat the green bricks as much as
it will before turning on the heat of the furnaces, or it may be caused to
.flow into the fires for feeding them with heated air. This is accom-
plished by means of the chambers a¹ under the ash-pits connected by
the passages
b' and c¹, which connections are controlled by dampers e¹.
The passages 6' serve to connect together the adjacent furnaces on one
.side of the kiln, and the passage c³ connect those of the opposite sides
together.
The mode of burning the bricks, and thus utilizing the heat, will now
be described with reference to Figures 1, 2, and 3, one of the compart-
ments G being charged with green bricks through an opening H³, with
which each is provided for the purpose, and which is temporarily walled
up while burning. A fire is started in the furnace adjacent to it, and
the heat passes into it through the passage f¹, thence down between the
bricks through the compartment containing them and the floor, and
through the passages under the floor to the passage Q, escaping into the
chimney, which is divided vertically for a suitable distance into as many
flues Qas there are passages Q entering it, each flue being controlled by
its appropriate damperm for preventing the draught from one compartment
from interfering with that from another. The damper e¹ under the
burning furnace is kept closed while this operation is going on, but
when the bricks have become sufficiently burned, and it is necessary to.
cool them off, the heat is conducted from the burned compartment back
through its passage f¹ and furnace down through chamber a¹ and

page_text: passage b', up through the other furnace and its passage f into the
adjoining compartment, containing green bricks, when the next one to
be burned is on the same side of the chimney as that last fired; but if
on the other side of the chimney the heat is conducted along the
passage c¹, under or around the chimney to the opposite side, and up
through the furnace to the compartment in the same way. For accom-
plishing this the damper m in the passage Q₁ of the chamber to be
burned is opened, the damper m of the passage Q₁ of the chamber to be
cooled is closed, the dampers of the passages y are closed, the passages i
of the compartment to be cooled are opened, the dampers e¹ of the
furnaces through which the air from the compartment to be cooled must
pass are opened, the other dampers e¹ are closed, and the passages i of
the compartment to be burned are closed. When the compartment
having the green bricks has thus been heated up equal to that of the
one cooling off so that it cannot be further heated thereby, the remaining
heat in the cooling compartment will be utilized to feed the fire, which
will then be started in the furnace of the compartment thus partially
heated, and fed with heated air from the compartment cooling off as long
as any heat remains in it, whereby all the heat of a burned compartment
lost heretofore will now be economized. After the remaining heat is all
used the air for the support of combustion will be supplied to the furnace
through the passages y in the regular way, and the draught through the
burned compartment will be stopped.
It will thus be seen that the operation of the kiln, so far as the
shifting of the flow of heated and cold air is concerned for burning and
cooling off, is controlled by the dampers of passages Q', y, i, and
chambers a¹, all of which, excepting Q₁ in the chimney, are at the
bottom of the kiln, where they can be worked most conveniently, and
what is much more important and one of the essential objects of the
arrangement is, they are all so arranged as not to be subject to any such
degree of heat as will materially affect them; consequently they
may be made of light and cheap material, and will not have to be
replaced as often as when arranged where they are more exposed to
heat. An underground passage g is arranged in connection with the
chambers a¹ and passages b¹, c', for conducting the heat to dry houses
(see Figures 2 and 3 at ġ), through which the heat will be caused to
flow by having all the dampers e³ closed except the one admitting heat
to it.

page_text: Openings giving access to dampers m for repairs may be placed in
the chimney above the kiln, but they are not essential.
The seventh part of the Invention relates to an arrangement of
passages and dampers for admitting a large amount of air to the furnaces
above the fire when fresh fuel is added to supply adequate quantities of
oxygen at such times when the gases are liberated from the coal in
greater quantities than at other times, after which the air may be gra-
dually shut off as the liberation of the gases subsides. For thus
admitting the air passages h¹ are provided in the walls D³, D2, leading
from the mouths of the passages fupward and into the furnaces F, as
clearly indicated in Figures 1, 5, and 6, the point of discharging into the
furnace being about as high or a little higher above the grates than the
top of the fuel when the furnaces are newly charged, and the sliding
dampers are suitably arranged in connection for closing and opening
them. These dampers may be reached by a hooked rod presented
through the door of the furnace, and engaging an eye j³, or they may
have a rod extending through the wall to the front. In the Drawing
the passages h¹ extend from the mouths of the passages ƒ below the
grates upward to the furnaces, which has been thought in some cases
desirable; but these passages may be made directly through to passages f
horizonally above the fire, and will operate as well generally.
The eighth part of the Invention relates to the use of a large well or
chamber in a central position below the perforated floor of each com-
partment and the lateral passages below it. A covered passage leads
from this well to the smoke stack. The escaping currents pass into this
well or chamber before entering the escape passage, the object being to
insure the vertical descent of the heat uniformly throughout the whole
area of the compartments at the bottom, which effect cannot be secured
when the escape passage is capable of receiving the currents near the
top of the floor, because of the tendency of the heat to favor the most
direct course to the chimney. This part of the Invention is illustrated
at Figures 7 and 8, where A' represents the said wells or chambers under
the floors at the centre. C³, C², represent the covered passages leading
from the wells to the chimney for the escape of the hot air and gases.
These wells cause the heat to settle down through the floors alike at all
points before any lateral movement sets in, and whatever movement
there is, being toward the centre from all points, effects the equal dis-
tribution of the heat throughout the lowermost parts of the burning

page_text: compartments, and thereby obviates the defects arising from the induced
lateral currents above the floors. The floors will be supported over these
wells by any suitable system of arches.
With reference to this modified form of kiln, it may be remarked that
it has been found in practice that in order to secure the best possible
results it is desirable to follow immediately the descending stratum of
moisture (steam) or damp material (green bricks, &c.) with a degree of
heat of sufficiently high a temperature to complete the process of
burning at once, and without the necessity of drying the material far in
advance of the fire as has heretofore been donc. To this end the
substratum of gravitating steam generated from the green material is
used to retard the descending stratum of intense heat; this acts like an
automatic damper, effectually preventing the rapid escape of heat (which
when thus confined remains behind and completes the process of
burning), while at the same time the draught is not materially
obstructed. And to complete the burning of the lowermost courses of
bricks a quantity of steam and water must be retained after that of all
the bricks has been expelled from them to maintain the aforesaid
stratum of high heat on the lowermost courses for a considerable time,
or until after the automatic damper of steam has passed away from
below, say for example, to a distance of five feet, at which stage all the
bricks above are completely burned. It is therefore important to the
success of the burning operation that a sufficiently ample chamber
should be formed beneath the floor of the oven, to serve as a reservoir
for the retention of condensed steam until the completion of the
burning of the lower courses in the oven. This reservoir during the
burning process becomes filled with saturated steam, and also.contains
more or less water from condensation; this steam and water serves as an
automatic damper, and must become thoroughly vaporized or evaporated
and carried off up the chimney before any considerable quantity of heat
can escape or be lost, and by the time the sub-chamber is dried off the
contents of the oven will be completely burned.
The ninth part of the Invention consists of a modified arrangement
of the dampers for the connecting passages below the furnaces, the
object being to avoid the loading to which the dampers are liable when
arranged as shewn in Fig. 1, by the droppings from the furnaces which
interfere with the operation of them easily. This improvement is
illustrated at Figures 7 and 8. The dampers e¹ are arranged in vertical.

page_text: planes on the sides of the walls D2 with upper and lower grooved
supports d¹ in which they can slide forward and back for opening and
closing, by which the aforesaid inconvenience is wholly avoided.
The tenth part of the Invention consists of a modification of the
arrangement of the passages for the cold air currents for cooling off the
burned material, and utilizing the remaining heat in a burned com-
partment. f, Fig. 7, are passages through the walls D₁ from the
compartments to the connecting passages below the floors, either in
connection with the cold air inlet passages i as previously described, or
with corresponding passages (also shown dotted) at the top. This
arrangement differs from the other, which I consider the best, only in
that by it in one case the cold air which is admitted at the bottom will
rise among the burned material, and then after becoming heated be
drawn down again to the connecting passages 6', c¹, without passing
through the furnace, and in the other case it will enter at the top
and pass downward through the burned material to the passage f³.
These operations may be found desirable in some conditions of the heat
in the compartments.
Having now set forth the nature of the Invention of certain
improvements in kilns for burning bricks, tiles, and pottery, and
in the mode of utilizing the heat generated therein, as communicated
to me by my foreign correspondent, and explained the manner of
carrying the same into effect, I wish it to be understood that under the
above in part recited Letters Patent I claim,-
-
First. The combination of the two parallel arched structures A, B, 1
four furnaces E, and one smoke stack F, when constructed substantially
as herein specified.
Second. The arrangement of the rabbit joint connecting the roof
and sides of the kiln for the purpose described in the foregoing
Specification.
Third. The arrangement of the open floor composed of bricks P
supported on arched walls L, the said bricks and walls alternating with
spaces as described.
Fourth. The arrangement of the open floor ○ superimposed course
of bricks and combustible filling in the spaces between said bricks as a
described

page_text: Fifth. The arrangement in the adjoining furnaces and burning com-
partments communicating by passages f¹ as described, of passages with
appropriate dampers connecting the furnaces at the bottom and
passages i, also with dampers opening from the exterior into the com-
partments.
Sixth. The method herein described of utilizing the heat remaining
in a burned compartment by introducing cold air thereto, and passing
it through the mass of heated bricks to take up the heat thereof, and
thence to an adjoining compartment containing green bricks, and
through the latter by means of passages and controlling dampers there-
fore so arranged that the remaining heat in any one compartment can
be conducted to any other as herein-before described.
.Seventh. The connection of the furnaces at the bottom by
passages b, c, substantially in the manner specified.
Eighth. The arrangement of the cold air passages y, f, and h³, as
herein-before described for admitting hot air to the furnace above the
grates.
Ninth. The means for equalizing the descent of the heat through the
bricks, substantially as specified with reference to the modified form of
kiln shewn at Figures 7 and 8.
Tenth. The dampers e¹ for controlling the connecting passages below
the furnaces arranged as shewn in Figures 7 and 8.
Eleventh. The passages f² from the compartments to the chambers a¹
arranged as shewn in Fig. 7, in connection with either the inlet
passages or 22.
In witness whercof, I, the said Alfred Vincent Newton, have herc-
unto set my hand and seal, the Twenty-second day of July, in
the year of our Lord One thousand eight hundred and seventy-
two.
A. V. NEWTON. (L.S.)