IMPROVE- MENTS IN KILNS OR OVENS FOR BURNING OR FIRING BRICKS, TILES, PIPES, AND POTTERY OR EARTHENWARE, AND IN THE MODE OF CHARGING THE OVENS OR PLACING OR, SETTING: THE ARTICLES THAT ARE TO BE FIRED THEREIN
Year: 1858

page_text: LETTERS PATENT. to William Basford; of Longport, in the County of
Stafford, Brick and. Tile Manufacturer, for the Invention of "IMPROVE-
MENTS IN KILNS OR OVENS FOR BURNING OR FIRING BRICKS, TILES, PIPES, AND
POTTERY OR EARTHENWARE, AND IN THE MODE OF CHARGING THE OVENS OR
PLACING OR, SETTING: THE ARTICLES THAT ARE TO BE FIRED THEREIN."
Sealed the 20th July 1858; and dated the 22nd January 1858.
PROVISIONAL SPECIFICATION left by the said William Basford, at the
Office of the Commissioners of Patents, with his Petition, on the
22nd January 1858.
I, WILLIAM' BASFORD, of Longport, in the County. of Stafford, Brick and
Tile Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN KILNS OR OVENS FOR BURNING OR FIRING BRICKS, TILES, PIPES,
AND POTTERY OR EARTHENWARE, AND IN THE MODE OF CHARGING THE OVENS, OR
PLACING OR SETTING THE ARTICLES THAT ARE TO BE FIRED THEREIN," to. be.. as
follows:-
My Invention of "Improvements in Kilns or Ovens for Burning or Firing
Bricks, Tiles, Pipes, and Pottery or Earthenware, and in the Mode of Charging
the Ovens or Placing or Setting the Articles that are to. be Fired therein,"
relates, in the first place, to various improvements in the construction of. kilns or
ovens, or of arranging the internal parts, the objects of most of the improve-
ments being economy in construction or in the comsumption of. fuel, or the
more equable and uniform distribution of the heat given off from the fires, so

page_text: that neither the oven nor any of the articles to be fired therein may be
damaged by any excess of heat at particular parts of the oven, as is now
frequently the case.
Kilns or ovens of the ordinary construction are usually built of a round or
circular form with a dome top, and mouths or openings for the fires are made
all round at equal distances apart. These distances are usually from four to
five bricks long, and the fire draughts all converge from the circumference
towards the centre, where the gaseous products of combustion commingle, and
ultimately escape through an opening made at the centre of the dome. The
triangular shaped spaces between the fire draughts are furnished with rows of
bricks of suitable height, and the whole surface above is covered over with tie
bricks so as to form an even floor throughout, and on which are placed the
bricks, tiles, pots, pipes, or other articles to be fired. Owing to the distance
apart of the mouths and consequently of the fire draughts as usually con-
structed, there is a want of uniformity of heat throughout the kiln or oven,
some parts being much hotter than others, and I have found that by making
the mouths and fire draughts of smaller dimensions than usual, and increasing
their number so as to reduce the space between them, I can obtain a much
more uniform and regular heat throughout the kiln than heretofore.
Another improvement relates to a novel mode of arranging the fire draughts.
of kilns or ovens; the usual way is to construct them in radial lines converging
towards the centre of the oven or kiln; instead of which I propose to arrange
them in parallel lines across the kiln from side to side, having mouths or
openings at back and front, or at each end of the fire draughts, which may,
however, be divided at the centre if required. The kiln or oven may be
circular in form as heretofore.
Another improvement consists in constructing a square kiln with parallel
fire draughts extending from back to front as in the round one just mentioned.
In this instance the walls are to be built up square or nearly so, and vertical
to a certain height, and then the corners must be drawn in gradually and
covered in with a circular dome, so as to present all the convenience of rever-
beration as in a circular oven or kiln....
The flues nearest the side walls I prefer to construct only four and a half
inches wide, and thereby the heat is confined and is thrown on to the bricks or
articles placed at the side to be burned.
Another improvement relates to the mode of constructing the dome top of
ovens or kilns, and instead of or in addition to making only one hole or opening
at the top of the dome and at the central part, as is usually the case, I pro-
pose to make three, four, or more openings round the top, so that I may close or

page_text: open one or more of such holes or openings as may be required, and I am
thereby enabled to throw or concentrate the heat on any particular part or
parts of the kiln or oven, should such part or parts seem to require it: These
holes are provided with covers or stoppers which may have air holes made in
them so as to regulate or stop the draught altogether.
Another improvement relates to a novel plan of constructing the interior
parts of the oven. Instead of building up temporary walls eight or nine bricks
high, I build permanent walls about five bricks high, and in the spaces
between the flues or fire draughts I form passages by placing fire bricks on
edge or otherwise, and on this I build the floor of upper chambers, in which,
when the chambers are completed, are placed the articles to be burned or
fired. The arrangement of the fire flues may be radial as heretofore, and the
chambers to be built thereon are constructed with parallel walls as explained
in reference to the square kiln or oven. On the top of these chambers, when
covered in, are placed any rough or coarse articles that require firing, such as
roof or floor tiles, while in the chambers are placed the finer articles.
The next part of the Invention relates to pottery kilns or ovens. The kiln
or oven is made circular, as usual, the fire draughts or flues being all made to
tend towards the centre, as is well understood. The walls of the fire draughts
are built up of convenient height, so as to form chambers or spaces between
the fire draughts to receive the seggars. The floors of these chambers are
supported upon rows of bricks arranged so as to divide the under part into
flues or passages, through which the heat is made to circulate so as to heat
the chambers. The floors are formed with a double layer of bricks or tiles,
to prevent the flame from entering the chambers and discoloring the pottery
ware that is being fired. And in order to heat the chambers all round so as
to maintain a uniform heat throughout the chambers, an external flue is
carried round the oven or kiln to conduct heat round the outer walls of the
chambers. The chambers are of course covered over at top with bricks
or tiles, so as to form close chambers or ovens into which the flame and smoke
froin the fuel cannot enter.
In large ovens some inconvenience is experienced in heating them uniformly
throughout if large mouths are employed and intense heat is generated; at
some places great danger of spoiling some of the goods placed nearest the
furnace or fire ensues. To obviate this and other inconveniences I propose
to employ additional mouths and fire draughts as in the brick kiln or ovens, and
some of the fire draughts may be carried through or under the firing chambers,
so as to impart heat thereto and at the same time conduct the flame from the
fire direct to the central part of the kiln. By this means the middle of the

page_text: chambers is sufficiently heated without having too large a fire and intense a
heat at other places, and at the same time heat is carried direct to the centre
of the kiln, and therefore all parts are more uniformly heated than heretofore;
by this arrangement the fires need not be made so large as usual nor the heat
so intense. In my new pottery ovens I propose to divide the space between
the fire draughts into two parts, that nearest the circumference is constructed
in such a manner as to form closed chambers, as above mentioned, in which
glazed ware or the finer kinds of biscuit are fired. The inner parts of the
spaces are divided off by a circular wall and flue, and may be considered as
open chambers or spaces in which commoner work or articles may be fired.
The bricks and tiles of which the walls and floors of the kiln or oven are
constructed are made of a combination of fire-clay and flint chippings or
calcined flints pounded until the reduced material will run through a riddle
or sieve with quarter-inch meshes; rough sandstone pounded coarsely may
also be used. By making the tiles and bricks with these materials I find
that they will stand the heat much better than when made in the usual
manner.
The last part of my Invention relates to a novel mode of charging the ovens
or placing or setting the articles that are to be fired therein. In charging
ovens in the ordinary way the articles to be fired are usually placed one on
the other, and are piled up in this manner as high as it is deemed prudent
and safe; sometimes, however, accidents occur in consequence of the super-
incumbent weight of the upper or topmost articles; the lowermost are crushed
and injured or the whole pile may be thrown down and damaged by some of
the under articles giving way. In order to prevent such accidents I build
up in the firing chambers temporary walls of from two to three bricks or more
high, according to the nature of the articles to be fired; between these
temporary walls I place as many articles as there is room for piling up one on
the other such articles as will admit of it until they reach the level of the top
of the temporary walls, on which I then place tie bricks or tiles extending
from wall to wall, and thus form another floor on which may be placed another
series of articles to be fired. The bricks of which the temporary-walls are
constructed may either be provided and kept for the purpose or they may be
bricks or tiles which themselves require firing, but if bricks or tiles of this
kind are employed care must be taken that they be strong enough to sustain
the superincumbent weight.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Basford in the Great Seal Patent Office on the 22nd
July 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BASFORD, of Longport, in the County of Stafford, Brick and Tile Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of January, in the year of our
Lord One thousand eight hundred and fifty-eight, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said William Basford, Her special license that I, the said William Basford,
my executors, administrators, and assigns, or such others as I, the said
William Basford, 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 KILNS
OR OVENS FOR BURNING OR FIRING BRICKS, TILES, PIPES, AND POTTERY OR
EARTHENWARE, AND IN THE MODE OF CHARGING THE OVENS OR PLACING OR SETTING
THE ARTICLES THAT ARE TO BE FIRED THEREIN," upon the condition, (ainongst
others,) that I, the said William Basford, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Basford, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being bad to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
My Invention of improvements in kilns or ovens for burning or firing
bricks, tiles, pipes, and pottery or earthenware, and in the mode of charging
the ovens, or placing or setting the articles that are to be fired therein,
relates, in the first place, to various improvements in the construction of kilns
or ovens, or of arranging the internal parts, the objects of most of the
improvements being economy in construction, or in the consumption of fuel,
or the more equable and uniform distribution of the heat given off from, the

page_text: fires, so that neither the oven nor any of the articles to be fired therein may
be damaged by any excess of heat at particular parts of the oven, as is now
frequently the case. Kilns or ovens of the ordinary construction are usually
built of a round or circular form, with a cone or dome top, and mouths or
openings for the fires are made all round at equal distances apart. These
distances are usually from four to five bricks long, and the fire draughts all
converge from the circumference towards the centre, where the gaseous
products of combustion commingle, and ultimately escape through an opening
made at the centre of the cone or dome. The triangular-shaped spaces
between the fire draughts are furnished with rows of bricks of suitable
height, and the whole surface above is covered over with a course of bricks
so as to form an even floor throughout, and on which are placed the bricks;
tiles, pipes, or other articles to be fired. Owing to the distance apart of the
mouths, and consequently of the fire draughts, as usually constructed, there
is a want of uniformity of heat throughout the oven, some parts being much
hotter than others, and I have found that by making the mouths and fire
draughts of smaller dimensions than usual, and increasing their number so
as to reduce the space between them, I can obtain a much more uniform
and regular heat throughout the oven than heretofore.
In the accompanying Drawings I have shewn at Fig. 1 a sectional repre-
sentation of an oven constructed according to my improvements for burning
or firing front. or facing bricks, floor tiles, or other articles of that kind of
the better class; Fig. 2 is a vertical section of the same. This oven with
very trifling modifications will be equally applicable for firing pottery or
earthenware in seggars, and will be hereafter referred to for that purpose.
It will be seen, on referring to Fig. 1, that there are sixteen mouths a, a, a, a,
a, a, a, a, for firing the oven, and a corresponding number of passages b, b,
6*, for conducting the heat from the fire to the interior of the oven. It
will be seen on referring to the Figures that there are holes or openings made
in the top or covering bricks of all the passages b, b, b, b, for the purpose of
allowing the heat to escape from the passages into the interior of the oven.
The other eight passages or fire draughts marked 6*, *, *, *, conduct the
heat beneath the floor to the central hole of the oven. By this arrangement
and mode of constructing the fire draughts or passages, whereby every alternate
passage conducts the heat beneath the floor, the heat becomes more equably
or uniformly distributed throughout the oven, and therefore the goods placed
on the floor of the oven will be burned or fired in a better and more uniform
manner than heretofore.
b",
Instead of constructing "bags" in front of the mouths, as is usual in

page_text: ordinary ovens, I build a flue c, c, round the interior of the oven, and 'makė
all the fire draughts or passages communicate therewith. The covering bricks
of this circular flue are perforated so as to allow the heat to escape therefrom
into the oven, as indicated by the arrows in Fig. 2. On the floor of the oven
so constructed the bricks or tiles to be fired are placed one upon another to
any convenient or suitable height, the rows, being so arranged that the heat
from the fires may circulate through the mass, and effectually fire every
article placed on and above the floor of the oven as near the top as
practicable.
I would observe that although I have shewn in the accompanying Drawings
sixteen fire draughts or passages, I do not mean or intend to confine myself
to that number, as a larger or smaller number may be employed with
advantage.
:
1
3
Under this head of the Invention, I claim.conducting every alternate fire-
draught under the floor, as herein shewn and described, and so constructing
and arranging the fire draughts or passages and flues, that the heat from the
fires may be more equally and uniformly diffused throughout the oven, and
the firing of a better class of front bricks and floor tiles is more effectually
performed than in ovens of the ordinary construction.
Another improvement relates to a novel mode of arranging the fire draughts
of ovens. The usual way is to construct them in radial lines converging
towards the centre of the oven; instead of which, I propose to arrange them
in parallel lines across the oven from side to side, having mouths or openings
at back and front or at each end of the fire draughts, which may, however, be
divided at the centre, if required. The oven is circular. in form as heretofore.
Fig. 3 is a sectional plan view of an oven (taken in the line of Fig. 4) for
burning bricks and tiles constructed in this manner; Fig. 4 is a vertical
.section of the same, taken in the line 1, 2, of Fig. 3; Fig. 5 is another
vertical section taken in the line 3, 4, of Fig. 3. a, a, represent the mouths
or fire-places of the oven; b, b, are the draughts or passages which extend
across the oven in lines parallel to each other, and are divided across. the
centre of the oven by the wall c; there are transverse draughts d, d, which
connect the main passages or draughts b, b, and by which the heat is equably
circulated beneath the floor on which the chambers e, e, are constructed. The
articles to be burned are placed in these chambers, and when full, the chambers
are covered over with flat tiles or bricks, so as to form. a floor. for the tie-
over bricks, on which is placed any other bricks, tiles, or pipes that require
firing. It should be observed that between each chamber e, and also around
just within the inner wall of the oven are flues or draughts f, f, in which the

page_text: heat is free to circulate before it passes upwards through the openings g, g, to
burn the articles placed above the chambers before passing through the outlet
at the top of the oven.
Under this head of the Invention I claim arranging the fire draughts or
passages in parallel lines (as shewn in the Drawing), and having mouths at
each end; I also claim the use of the chambers or hollow compartments,
wherein the articles, such as front bricks or floor tiles are placed to be fired.
.. Another improvement consists in constructing a square kiln with parallel
fire draughts, extending from back to front, as in the round one just men-
tioned. A kiln of this construction is shewn in sectional plan at Fig. 6;
Fig. 7 is a vertical section of the same taken in the line 1, 2, of Fig. 6. In
this case the walls are to be built up square to a suitable height, say, six feet,
and then the corners must be drawn in gradually, until the part upon which
the conical or dome top rests forms a circle. By this means all the advantages
of a reverberation of the heat in the interior of the kiln will be obtained as in
a circular oven. By building the lower part of the kiln in a square form, I
am enabled to form chambers e, e, between the parallel fire-draughts b, b, and
thus to economise the heat. These chambers are constructed of groove and
tongue or rebated bricks set edgewise, the joints being secured with fire-clay
cement, so as to prevent the blaze from entering the chambers; the walls are
built on a hollow floor, beneath which the draughts band d circulate, in a
similar manner to that shewn in Figures 8, 4, and 5. The walls of this square
kiln I sometimes build eight or twelve feet high, and turn a dome-top off the
square wall; when this is done, I carry the chambers e, e, up as high as the
square side walls, and fill them with such articles as front bricks, roof, and
floor tiles. When glazed bricks are intended to be burnt, I construct the
side walls of the chambers with perforated bricks, through which the fumes
from the burning salt pass to glaze the articles under operation. In my
Patent, dated Twentieth of January, One thousand eight hundred and forty-
four, I claimed the use of perforated bricks to build the side walls of the
chambers, without reference to or ever using salt in the mouths. This I
disclaim as old.
Under this head of the Invention I claim constructing kilns for burning or
firing bricks, tiles, or pottery of a square form, for the purpose of more con-
.veniently forming chambers therein, as above described, and surmounting such
kilns with a cone or dome top.
Another improvement relates to the mode of constructing the dome or
conical top of ovens. Instead of making only one hole or opening near the
top of the cone or dome, and in the centre, as is usual, I propose to make

page_text: three or four openings as shewn at n, n, in Fig. 4, round and just below the
top of the cone or dome or conical top, as shewn in the Figure, so that I may
close partially or otherwise one or more of these openings as may be required,
thereby enabling me to throw or concentrate the heat on any particular part
of the oven, when such part or parts appear backward, as is often the case in
firing bricks or tiles. These holes are furnished with stoppers having air-
holes made in them, so as to regulate the draught. These holes or openings
are also used for the purpose of introducing cobbles of coal round the sides of
the oven to strengthen the heat therein instead of throwing the cobbles down
the central hole, as is now done. By the use of these holes n, I am enabled
to contract the centre hole and thus further to economise heat. At the base
of the cone it will be seen by reference to Fig. 4 that there is a set-off o
projecting inwards all round the inside of the oven; this is for the purpose of
narrowing the top of the oven, so as to increase the heat and thereby econo-
mizing fuel..
What I claim under this head of the Invention is, forming holes or open-
ings near the top of the cone or dome of the oven for the purposes above
described. I also claim making a set off in the brickwork at the base of the
cone or top of the body of the oven, as above described.
The next part of the Invention relates to pottery kilns or ovens (see Fig.
8). The oven is made circular as usual, the fire draughts or flues. being all
made to tend towards the centre as is shewn in the brick oven, represented in
Fig 1, and already described. The walls h of the fire draughts are built up of
convenient height, and are extended inwards above three feet. Cross or
transverse walls are constructed from the ends of the radial walls, so as to
form chambers or spaces i, i, between the fire draughts, in which chambers
the seggars containing the goods to be fired are placed, and are thus pro-
tected from any undue action of the heat of the goods to be fired. The floors
of these chambers are supported upon rows of bricks between the firė draughts
and are so arranged as to divide the under part into flues or passages through
which the heat is made to circulate so as to heat the chambers and the interior
of the oven more uniformly. The floors are formed with a double layer of
bricks or tiles, to prevent the flame from entering the chambers and discoloring
the pottery ware that is being fired; and in order to heat the chambers all
round, so as to maintain an uniform heat throughout, a flue is carried round
inside the oven, and by communicating with the mouths, will conduct the heat
round the outer walls of the chambers, which are covered over at top with
perforated bricks, as shewn in the Drawing.
In this pottery oven it will be seen that there are sixteen 'mouths (eight of

page_text: which are furnished with flues in the place of bags, extending inwards about
three feet, built on the floor of the oven facing its mouth). The heat from
eight of these sixteen mouths is conveyed partly up the flue by the wall of the
oven, and partly under the floor of the oven; the heat from the other eight
working up the flue, thence under the floor to the centre hole of the oven, the
object being to lessen the wear and tear of the mouths and oven; and to heat
the oven uniformly.
. I claim under this head of the Invention the mode above shewn and
described of constructing a potter's oven.
The bricks and tiles of which the chamber, floors, and walls above described
are constructed, are made of a combination of fire-clay and flint chippings, or
calcined flints, pounded until the reduced material will run through a riddle
or sieve with about quarter inch meshes. Rough sandstone of a refractory
mixture, pounded coarsely may also be used. By making the bricks of these
materials I find that they will stand a repetition of heat much better than
when made in the usual manner.
I claim, under this head, making the bricks for the walls and floors of the
chambers, of the materials above mentioned.
The last part of the Invention relates to a novel mode of charging the ovens
.or placing or setting the articles that are to be fired therein. In charging
ovens and kilns in the ordinary way, the articles to be fired are usually
placed one on the other, and are piled up in this manner as high as it is
deemed prudent and safe: Sometimes, however, accidents occur in conse-
quence of the superincumbent weight of the upper or topmost articles, the
lowermost are crushed and injured; or the whole pile may be thrown down
and damaged by some of the under articles giving way. In order to prevent
such accidents, I build up within the firing chambers temporary walls p, p, of
from two to three bricks or more high, as shewn in Fig. 7, according to the
nature of the articles to be fired; between these temporary walls I place as
many articles q, as there is room for piling up, one on the other, such articles
as front bricks, roof and floor tiles, until they reach near to the top of the
temporary walls, on which I then place tie or cross-bricks r.extending from
wall to wall, as shewn in the Drawing, and thus form another floor, on which
may be placed another series of articles.q', consisting of front bricks or floor
tiles to be fired. The bricks of which the temporary walls are constructed,
may either be provided and kept for the purpose, or they may be bricks or
tiles, which themselves require firing, such as front or floor bricks set on
edge; but if bricks or tiles of this kind are employed, care must be taken
that the cross bricks be strong enough to sustain the superincumbent weight.

page_text: Under this head of my Invention I claim the construction of temporary
walls within the firing chambers for the purpose of taking off the super-
incumbent weight of the articles to be fired from those beneath them, as
above shewn and described.
In witness whereof, I, the said William Basford, have hereunto set
my hand and seal, the Twentieth day of July, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
J. W. POWELL, Agent,
16, King Street, Burslem.
WILLIAM BASFORD. (L.S.)