IMPROVEMENTS IN POTTERY KILNS
Year: 1867

page_text: LETTERS PATENT to Henry Doulton, of High Street, Lambeth, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN POTTERY
KILNS."
Sealed the 5th July 1867, and dated the 9th January 1867.
PROVISIONAL SPECIFICATION left by the said Henry Doulton at the
Office of the Commissioners of Patents, with his Petition, on the 9th
January 1867.
I, HENRY DOULTON, of High Street, Lambeth, in the County of Surrey,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
POTTERY KILNS," to be as follows:-
For these purposes in constructing a kiln for burning salt glazed and other
pottery ware it is to be used of the usual form, and is to be arranged for pro-
ducing a down draft by having a closed roof or ceiling and a reticulate floor
down through which the products of combustion pass into a flue under the
floor, as heretofore. The upper part of the kiln is to be of the ordinary con-
struction with openings through the roof or ceiling for the introduction of
the salt when used for salt glazed ware, but which openings are to be closed
at other times. Above the ceiling or top of the kiln is the ordinary funnel
which may be used as a drying chamber when the kiln is burning, it being
usually closed near the top with an ordinary skive; the peculiarity of this
Invention consisting in constructing a flue exterior of the burning chamber
of the kiln leading from the chamber or flue below the floor of the kiln up to

page_text: and in connection with the funnel by which the heating of a kiln is more
advantageously conducted and the heat derived from the fuel more usefully
employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Doulton in the Great Seal Patent Office on the
9th July 1867..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DOULTON, of High Street, Lambeth, in the County of Surrey, 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 sixty-seven, in the thirtieth year of Iler
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Doulton, Her special licence that I, the said Henry
Doulton, my executors, administrators, and assigns, or such others as 1,
the said Henry Doulton, 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 POTTERY KILNS," upon the condition (amongst others)
that I, the said Henry Doulton, my executors or administrators, by an instru-
ment 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 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 Henry Doulton, 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 thereof, that is to say:
•
This Invention has for its object improvements in pottery kilns, and is
The kiln is con-
applicable especially to kilns for burning salt glazed ware.
structed in the usual manner in so far that the goods to be burnt are stacked
in a burning chamber which is arched over at the top, and has a number of
fire-places arranged around it, but the draft from these fires, in place of

page_text: passing upwards through openings in the arched roof of the chamber into the
funnel above, as is usual, is caused to pass downwards through a reticulate
floor into a chimney or flue formed against the exterior of the drying chamber
and leading up to or near to the top of the funnel; by this arrangement the
heating of the kiln is more advantageously conducted, and the heat from the
fires is more economically applied; the funnel also becomes available for use
as a drying chamber.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings hereunto
Figures 1 and 2 are vertical sections, and Figure 3 is a plan of a
kiln originally built in the ordinary manner, but altered according to my
Invention.
a, a, is the burning chamber enclosed at the top by the arch b, which was
originally perforated to let the draft pass upwards, but the holes are now
closed and luted down; they may, however, be opened for the purpose of
throwing salt down amongst the ware in salt glazing, or if for any temporary
purpose it is desired to work the kiln in the old way; c, c, are the fire-places
arranged around the burning chamber, and c¹, c', the "bags" or screens in
front of them to prevent the fires playing too directly on the ware; d is the
funnel which now may be used as a drying chamber, and has the ordinary
opening into it; e is the skive or valve which is now usually kept closed.
The reticulate bottom of the kiln is formed with a number of horizontal flues f, f,
communicating with two other horizontal flues 9, 9, passing diametrically
across the bottom of the chamber, and all these flues are enclosed at the top
by a paving of fire-brick blocks h, h, so formed and laid as to leave vertical
passages for the draft to pass into the flues f and g. A plan of a portion of
this paving is shown at Figure 4. i, i, is the chimney or flue built up outside
the burning chamber and funnel; it communicates at the bottom with the
flues 9, 9, and enters the top of the funnel above the skive; ¹ is a damper for
regulating the draft in the chimney or flue i or for shutting it off altogether if
it is desired to work the kiln for a time in the old way. I would remark
that in constructing a new kiln the chimney or flue i need not project, as in
the Drawing, but may be divided into two or more parts, and be taken up in
the thickness of the piers between the fire-places.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would have it understood that I do not claim generally

page_text: the arranging kilns in such manner that the draft of the fires may pass
downwards by the bottom of the burning chamber; but I do claim the
arrangement, herein-before described, with the reticulate bottom and the
chimney or flue ascending against the side of the burning chamber and
funnel.
In witness whereof, I, the said Henry Doulton, have hereunto set my
hand and seal, this Ninth day of July, in the year of our Lord One
thousand eight hundred and sixty-seven.
HENRY DOULTON. (L.S.)