IMPROVEMENTS IN THE CON- STRUCTION OF KILNS FOR BURNING STONEWARE, RED CLAY WARE, PORCELAIN, Camus Live OR PARTHENWARE
Year: 1858

page_text: LETTERS PATENT to John Cliff, of the Imperial Potteries, Lambeth, iu
the County of Surrey, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF KILNS FOR BURNING STONEWARE, RED CLAY WARE, PORCELAIN,
Camus Live OR PARTHENWARE"
PROVISIONAL SPECIFICATION left by the said John Cliff at the Office
of the Commissioners of Patents, with his Petition, on the 6th November.
1858.
I, JOHN CLIFF, of the Imperial Potteries, Lambeth, in the County of Surrey,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF KILNS FOR BURNING STONEWARE, RED CLAY WARE, PORCELAIN,
AND ALL OTHER KINDS OF EARTHENWARE," to be as follows:-
This Invention has for its particular objects, firstly, the great economy of
space; secondly, economy of fuel; and, thirdly, the more thoroughly consuming
of the smoke than by kilns of the ordinary kind.
The first is effected by entirely dispensing with the bungs, or bags and
saggers, or brick erections in the centre or interior of the kiln; the second

page_text: being effected by confining the flame and heat, and excluding the cold air;
the third being effected by passing the smoke together with the flame
through narrow channels and pipes, the effecting of these objects being better
understood by the following description :-
Within the proper lining of the kiln is built a second lining at a short dis-
tance from the former, the thickness of which varies according to the quality
of the fire-bricks used; this second lining reaches up to the commencement of
the dome, leaving a circular opening at this height entirely round the inner
lining. The bottom, which is hollow and communicates with the fire, has
holes cut in it at proper distances, and over each of these orifices is erected a
column of hollow pillars of various lengths to suit various sized articles, and
have collars of greater diameter (also with holes) placed upon and between
each; these columns rise to the same height as the inner lining before men-
tioned. Upon the ledges of the collars (thus left protruding) rest quarries
of various shapes according to the arrangement of the pillars, which quarries
thus form so many new floors or cupboards for setting the ware in. The top
tier are permanently left entire (the hollow pillars finishing above their top),
and are close jointed, thus leaving the body of the kiln perfectly from any
draught through it. To effect the consumption of smoke, air is introduced at
the furnace mouth by means of perforated arches to mingle with the smoke
behind the fire. Should this not have the full effect, the remaining portion is
consumed on its journey through the bottom and up the hollow pillars, or up
the narrow opening between the two linings. The flame from the hollow
pillars and the annular opening which make their joint exit through the
opening in the centre of the crown, are deflected to the sides of the kiln by
the superposition of a quarried floor, where the flame is again met by a current
of fresh air through the holes left in the cone of the kiln, at or about a level
with the crown of the kiln.
Solid pillars may be used, but not with the same advantage as the hollow
ones, as by the latter the heat is more equally diffused throughout the body of
the furnace, and also greatly assists in consuming the smoke, neither of which
could be effected by solid pillars.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Cliff in the Great Seal Patent Office on the 6th
May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOIN
CLIFF, of the Imperial Potteries, Lambeth, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Cliff, Her special licence that I, the said John Cliff,
my executors, administrators, and assigns, or such others as I, the said
John Cliff, 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
THE CONSTRUCTION OF KILNS FOR BURNING STONEWARE, RED CLAY WARE, PORCELAIN,
AND ALL OTHER KINDS OF EARTHENWARE," upon the condition (amongst others)
that I, the said John Cliff, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should par-
ticularly 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 John Cliff, do hereby declare the
nature of the 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 thereof:
This Invention has for its objects, firstly, the great economy of space;
secondly, economy of fuel; and, thirdly, the more thoroughly consuming of the
smoke than by kilns of the ordinary kinds.
The first is effected by entirely dispensing with the bungs and saggers, or
brick crections in the centre or interior of the kiln; the second being secured
by confining the heat within the body of the kiln, and prevent its being
carried off by draught; the third being realized by passing the smoke,

page_text: together with the flame through narrow channels and pipes; the accom-
plishment of these objects being better understood by the following
description:
Within the lining proper of the kiln is built a second lining at a short dis-
tance from the former, which lining reaches up to a level with the commence-
ment of the dome, leaving a circular opening at this height entirely round the
inner lining. The bottom, which is hollow, and communicates with the fire,
has holes left in it at proper distances, and over each of these orifices is erected
a column of hollow pillars of various lengths (to suit various sized articles),
and have collars of greater diameter (also with holes) placed upon and
between each. These columns rise to the same height as the inner lining
before mentioned. Upon the ledges of the collars (thus left protruding)
rest quarries of various shapes, according to the arrangement of the pillars,
which quarries thus form so many floors or cupboards for setting the ware
in. The top tier is permanently left entire, (the hollow pillars finishing
above its surface,) and are close jointed, thus leaving the body of the kilu
perfectly free from any draught through it.
To effect the consumption of smoke, air is introduced at the furnace mouth
by means of a flue over the fire arch, descending at the back of the same
through an orifice behind the fire, as in furnaces at present in use. Should
this not have the full effect of consuming the smoke, the remaining portion is
decomposed on its journey through the bottom and up the hollow pillars, or
up the narrow opening between the two linings.
The flames from the hollow pillars, and the annular opening which make
their joint exit through the orifice in the centre of the crown, are deflected to
the sides of the kiln by the superposition of a quarried floor, where the flame.
is again met by a current of fresh air through the holes left in the base of the
cone of the kiln at or about a level with the crown of the kiln.
Solid pillars may be used, but not with the same advantage as the hollow
ones, as by the latter the heat is more equally diffused throughout the body of
the furnace, and also greatly assists in consuming the smoke, neither of which
could be effected by solid pillars.
In order to explain my said Invention as completely as possible, I now
proceed to describe the best means I am acquainted with for carrying the same
into practical effect, reference being had to the illustrative Sheet of Drawings
hereunto annexed, and to the numeral figures and letters of reference marked
thercon respectively, as follows:-

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical section of half a kiln, and Figure 2, plan view taken
through the line A, B, at Figuro 1. Similar letters of reference are used to
denote corresponding parts, in so far as such parts appear or can be seen at
cach of such said Figures respectively.
To effect the economy in space I build within the lining proper B of the
kiln, and at various distances from it (according to circumstances), a second
lining D, from the floor to the level of the commencement of the arch of the
kiln, leaving an annular space C round the entire kiln (supposing it to be
circular), from the base or floor line to the spring of the dome; at the base of
this circular flue, and at intervals, arc holes H, to connect it with a hollow
chamber I, under the floor of the kiln, in which floor are left a number of
holes at proper distances, over which are erected a series of perpendicular flues,
terminating on a level with the before-mentioned inner lining D, or slightly
above it by means of variable lengths of hollow pillars F, and collars of larger
diameter, as shown. These variable lengths of pillar and collar allow of
constructing quarry floorings E, E, across the kiln at any desired height, and
thus utilize a large amount of space hitherto impracticable. The floor of the
kiln and the top tier are fitted close, so that during the burning no flame,
smoke, or draught can approach the ware, thus effecting a rapid accumulation
of heat within the kiln to the point required, and by the removal of one quarry
opposite the door or entrance to the kiln, and four or five slabs from each tier
of the middle row (supposing the kiln to be circular), the kiln can be filled
and emptied with an amount of case and rapidity not possibly attainable in the
ordinary mode.
To effect the combustion of the smoke, I introduce cold air by means of an
opening from the front of and on the top of each fire arch G behind the
burning fuel. The smoke in its passage up the narrow annular flue C, and
up the hollow pillars F, by being so much divided, and having to travel over
so much more than ordinary heated surface, is more efficiently consunied,
and is again met at its exit into the funnel O, by streams of atmospheric air
passing in at openings N through the base of the same.
It will appear by the above that the products of the fuel are more equally
distributed through the body of the kiln, that the heat necessary is more
rapidly generated than in kilns of ordinary construction, and a consequent
reduction is made in the quantity of fuel used. The same means that admit
of more rapidly heating the kiln apply also to the cooling of the same, thus

page_text: allowing larger kilns to be filled and emptied within a stipulated time. The
ware fired in this or other closed kilns can be glazed with a colorless glaze by
means of salt being applied in a somewhat different manner than heretofore.
The present method of glazing has always been by putting salt on the fire,
and the draught drawing the decomposed chloride of sodium through and
about all the goods in the kiln; but the method I employ is introducing the
salt within the kiln when at the proper heat, at the same time excluding the
air, flame, dust, &c., which cannot be done in kilns of ordinary construction.
The working of this kiln will be more readily understood by referring to the
following short description of its various parts:-
A is the outer stock brick carcase of kiln; B, the ordinary lining of kiln;
C, the annular flue space; D, the internal lining of kiln; E, E, the quarries,
made to fit close to each other and to the pillars in the top and bottom tiers,
but may have slight hollows for hand holes in the rest; F, F, the hollow
pillars, each with its collar of larger diameter on its top, and supporting the
quarries E, E; G, the fire arch; H, communication with bottom chamber;
I, hollow bottom chamber; K, circular opening at the crown of kiln; L, fluc
from opening K to the annular flue M; M, the exit flue into the funnel O;
N, air holes through base of funnel; O, funnel; S, air flue.
Having now fully described and set forth the nature and object of my said
Invention of "Improvements in the Construction of Kilns for Burning Stone-
ware, Red Clay Ware, Porcelain, and all other Kinds of Earthenware," together
with the best micans I am acquainted with for carrying the same into practical
effect, I would remark, in conclusion, that I do not confine or restrict myself
to the precise details herein described and exhibited by the accompanying
Sheet of illustrative Drawings, as many slight modifications may be made
therein without in any way departing from the principle of my Invention; but
what I claim as my Invention intended to be secured to me by the herein in
part recited Letters Patent is,-
Firstly, the construction of the inner portion of kilus to supersede the
use of bungs, saggers, &c., by using in lieu thereof hollow or solid pillars in
connection with collars of larger diameter, supporting at any desired
height floors of quarries (or any sort of pillar built up from bottom to
top, which support without collars of larger diameter by means of notches or
otherwise).
Secondly, the more effectual consumption of smoke in pottery kilns by
means of a series of hollow pillars and annular flue and air openings at the
top of the crown.

page_text: Thirdly, the mode of excluding the air from the body of the kiln by means
of the internal lining.
Fourthly, the peculiar arrangement of hollow columns to generate heat
equally through the kiln.
Fifthly, the glazing of stoneware or other ware with a colourless glaze by
means of salt, in the manner above described.
Sixthly and lastly, the general combination of the parts herein described,
and exhibited in the accompanying Sheet of illustrative Drawings, for the
purposes herein described are set forth.
In witness whereof, I, the said John Cliff, have hereunto set my hand
and seal, this Fifth day of May, in the year of our Lord One thousand
eight hundred and fifty-nine.
JOHN CLIFF. (L..S.)
Witness,
L. J. WETHERELL,
Clerk to Messrs. Prince & Co.,
Office for l'atents,
4. Trafalgar Square, Charing Cross.