A NEW AND IMPROVED METHOD OF BUILD- ING AND CONSTRUCTING OVENS USED BY POTTERS AND CHINA MANUFACTURERS IN THE FIRING OF THEIR WARES
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
VENABLES, of Burslem, in the County of Stafford, Earthenware Manufacturer,
and JOHN TUNNICLIFF, of Burslem aforesaid, Bricklayer, send greeting.
WHEREAS Her most Gracious Majesty Queen Victoria, in and by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twentieth day of November last past, after reciting that we,
the said John Venables and John Tunnicliff, had, by our petition, humbly
represented to Her Majesty that we had, after considerable labour, trouble,
and expense, found out and invented "A NEW AND IMPROVED METHOD OF BUILD-
ING AND CONSTRUCTING OVENS USED BY POTTERS AND CHINA MANUFACTURERS IN THE
FIRING OF THEIR WARES," that we were the first and true inventors thereof, and
that the said Invention had never been practised or used by any other person
or persons whomsoever, to our knowledge or belief, Her said Majesty therefore
did give and grant unto us, the said John Venables and John Tunnicliff, our
exors, adiñors, and assigns, Her especial licence, full power, sole privilege, and
authority, that we, our exors, adñors, and assigns, and every of us, by our-
selves, or by our deputy or deputies, servants or agents, or such others as we,
our exors, admors, or assigns, should at any time or times agree with, and no
others, from time to time and at all times thereafter, during the term of years
therein mentioned, should and lawfully might use, exercise, and vend our said
Invention within that part of the United Kingdom of Great Britain and
Ireland called England, the Dominion of Wales, and Town of Berwick-

page_text: upon-Tweed, in such manner as to us, our exors, adññors, and assigns, or
any of us, should in our discretions seem meet; and that we, our exors,
admors, and assigns, should and lawfully might have and enjoy the whole
benefit, profit, commodity, and advantage from time to time coming, growing,
accruing, and arising by reason of the said Invention, for and during the
term of years therein and. herein-after mentioned; to have, hold, receive,
exercise, and enjoy the said licence, powers, privileges, and advantages for and
during and unto the full end and term of fourteen years from the date of such
Letters Patent next ensuing, and fully to be complete and ended, according to
the Statute in such case made and provided; in which said Letters Patent is
contained (amongst other things) a proviso, that if we, the said John Venables
and John Tunnicliff, should not particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, by an
instrument in writing under our hands and seals, or under the hand and seal
of one of us, and cause the same to be enrolled in Her Majesty's High Court
of Chancery within two calendar months next and immediately after the
date of such Letters Patent, then the said Letters Patent, and all liberties and
advantages whatsoever thereby granted, should utterly cease, determine, and
become void, as in and by the said Letters Patent, on reference thereto, will
more fully appear.
NOW KNOW YE, that we, the said John Venables and John Tunnicliff, in
compliance with the said proviso, do hereby describe and ascertain the nature
of our said Invention, and in what manner the same is to be performed, used,
and applied, by the following description thereof, videlcit:-
That whereas the ovens ordinarily used by potters and china manufacturers
in the process of firing their wares, both in the biscuit state and in the gloss
state (or glazing process), are so constructed as to require a much larger con-
sumption of fuel relatively to the quantity of ware therein contained than is
needful according to our method hereafter explained, and the manufacturers
thereby incur much unnecessary expense; we propose, by means of our Inven-
tion, to obtain additional space in the ovens for placing the stacks or tiers of
saggars (these stacks or tiers being called by the. workmen "bungs," and the
saggars being earthen pans or cases in which the wares are enclosed during
the process of firing), and this we are enabled to do by setting the outer and
larger circle or circles or bungs of saggars close to the sides of the oven all
round the same upon a ledge or shelf, or two or more ledges or shelves or
other basis, which we construct in the oven between the sides thereof and the
vents or orifices of the bags or flues by which the oven is heated, and we

page_text: thereby enlarge the capability of the oven for the firing processes to the extent
of such ledge or shelf, or ledges or shelves or other basis, and are enabled to
place in the oven a much larger quantity of goods for the firing processes, and
to complete such processes by the expenditure of no extra quantity of coals or
other fuel, and in as short or even a shorter space of time than are required
We
for the firing processes in ovens of equal dimensions heretofore in use.
deem it necessary here to explain that the ovens in ordinary use have no such
ledge or contrivance, and for want thereof a great portion of the heat is spent
upon the oven sides which might be applied to the benefit of the manufacturer,
and will be so applied by means of our Invention.
For the better explanation of our Invention we refer to the Drawings an-
nexed to this Specification, and the references thereon written; in which said
Drawings, Figure 1 represents the exterior of an oven on the improved con-
struction for which our Patent is obtained, but the exterior form of the oven
constitutes no essential part of our improvement. The bands, which are
represented as encircling the oven, are of iron, linked together the same as in
ordinary ovens. The letters A, A, A, in Figure 1 shew the arches over the
Foven mouths or fire-places at which the fuel is supplied, and which are upon
a similar construction to the mouths or fire-places of ordinary ovens, except
that the arches, lintels, or bearings over the mouths of our oven are constructed
of greater depth or thickness than in ordinary ovens, for the purpose of enlarg-
ing the interior capacity of the oven above the arches, lintels, or bearings, and
these arches, lintels, or bearings, with the other brickwork in the base of the
oven, support the ledges or shelves shewn in Figure 2, hereafter referred to ';
but it is not absolutely necessary, for the purposes of our Invention, that
arches should be used; but lintels, or any other architectural contrivance
whereby the side walls of the oven can be supported over the oven mouths,
may be indifferently employed. The letter B (in Figure 1) shews the entrance
to the inside of the oven, which is walled up during the process of firing, and
is in no respect different from the ovens in ordinary use. Figure 4 shews the
ground plan and horizontal section of our oven, with the oven mouths and
bags or flues. The upper half of this circle (marked No. 5) shews the sec-
tion of our oven with distinct bags or flues and arched fire-places taken above
the floor. The lower half of the same circle (marked No. 6) shews the
foundations of the oven with the flues under the floor, and a continuous circular
bag or flue, together with the basis of brickwork, on which we place the outer
circle of saggars, as in Figure 2, (letters X, X,) and which basis included the
space in the oven bottom, on which the outer circle of saggars may be raiseil

page_text: from the floor, as represented in Figure 3 (letters Z, Z). The number of
fire-places and bags or flues in every oven is in proportion to the size of the
oven. Their number, form, or shape is no essential part of our improved oven,
nor do we rely upon the particular construction of the bags or flues of our
ovens any farther than as they are necessarily adapted by their special position
to the interior of such ovens, as herein-after specified. Figure 2 contains an
upright section of our oven, shewing the base thereof with the fire-places and
flues, and the superstructure and interior of the oven. The ledges or shelves
on either side, marked with the letters X, X, constitute one peculiarity of our
oven. Upon these ledges, and round about the whole interior of the oven, we
place the outer circle of saggars for the process of firing the wares, whether
they be china or earthenware, and whether for biscuit or gloss. A portion of
this outer circle of saggars is represented in Figure 2, and each being therein
marked with the letter F. The width of this ledge will vary or admit of
variation according to the size of the saggars, or the space required for one,
two or more circle or circles of saggars, which may be placed thereon for the
firing processes; and though we consider ledges or shelves, as represented in
Figure 2, to be the most convenient and preferable kind of support for the
outer circle or circles of saggars, we also obtain the same end, though in a
manner we consider less advantageous, by constructing our oven without any
such shelves, as in Figure 3, and by placing the outer circle or circles of
saggars upon and rearing the same from the bottom or floor of the oven, as
represented in that Figure. For each of these contrivances we claim the
benefit of our Patent, the great advantage and peculiarity of which consists in
our introducing the heat through vents or orifices in the floor, or by flues or
bags raised above the floor along the inner side of one or more row or rows of
saggars placed round the oven walls, and thus admitting of a much larger
quantity of goods being fired in our improved oven than can be fired by means
of an equal quantity of coals or other fuel in any oven of the same size and
dimensions constructed in the method ordinarily used by potters and china
manufacturers. In Figure 2 of the annexed Drawings, over and along one
side thereof, a dotted outline, marked with the letters H, H, H, is intended to
represent an extension of the upper part of our oven, by constructing an addi-
tional ledge or shelf for receiving a circle or row of saggars behind the circle
or circles resting upon the ledges or shelves marked X, X, in the same Figure.
An oven constructed with this extension we call a double-ledged oven; it
requires a corresponding extension of the depth or thickness of the arches,
lintels, or bearings over the oven mouths, in order to support such additional

page_text: ledge, and may be made subservient to the firing of a still greater quantity of
ware with the same quantity of fuel than can be fired in an oven constructed
with a single ledge or shelf, as shewn in Figure 2, when divested of that
portion shewn by the outline H, H, H: This additional ledge will be formed
as represented in Figure 2 by the dotted line above the letter Y.
Now whereas we claim as our Invention the construction of an oven with
one or more ledge or ledges, as shewn at X in Figure 2, and indicated by the
dotted line above Y in the same Figure, together with the arrangement of flues
or bags there shewn, and also the construction of an oven without any ledge
or shelf, but with flues or vents either raised above the floor of the oven, as
shewn at 7 in Figure 3, or not at all raised, but being simply orifices in the
floor, as shewn at K in the last-mentioned, Figure, whereby we are enabled,
in each of such several modes of construction, to place one or more circle or
circles of saggars behind the flues or vents, and thereby greatly to enlarge the
capability of the oven for the processes of firing, without the expenditure of
any extra quantity of coal or other fuel whatever.
And such our Invention being, to the best of our knowledge and belief,
entirely new, and never before used within that part of Her said Majesty's
United Kingdom of Great Britain and Ireland called England, Her said
Dominion of Wales, or Town of Berwick-upon-Tweed, we do hereby declare
this to be our Specification of the same, and that we do verily believe this
our said Specification doth comply in all respects fully and without reserve or
disguise with the proviso in the said herein-before in part recited Letters
Patent contained; wherefore we do hereby claim to maintain exclusive right
and privilege to our said Invention.
In witness.whereof, we have hereunto set our hands and seals, this
Seventeenth day of January, in the year of our Lord One thousand
eight hundred and forty-two.
JOHN (L.S.) VENABLES.
JOHN (L.s.) TUNNICLIFF.
Signed, sealed, and delivered by the within-
named John Venables and John Tunnicliff,

page_text: AND BE IT REMEMBERED, that on the Seventeenth day of January, in
the year of our Lord 1842, the aforesaid John Venables and John Tunnicliff'
came before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Yra A

page_text: REFERENCES.
G. 1.A.A.A. Recesses over the mouths of Fireplaces which may be formed of arch
or otherwise as may be directed
B.Entrance to the Oven.
G. 2 A.A.Recesses over Fireplaces
C.C. Longitudinal Section of Fireplaces
D.D.
D:
Do
E.E. Sections of Glut Holes
of Flues from Fireplaces to the centre of Oven
EF Saggars enclosing the ware for the firing process
GGGGG. Sections and Elevations of Bags or Flues from Fireplaces
H.H.H. Outside of extension for double ledged Oven
XX. Ledges or Shelves for stacking outer row of Saggers on
Y.Proposed additional Ledge or Shelf for double ledged oven
G.3 Represents the section of an Oven, without, Ledges or Shelves, having
the outer circle of Saggars placed on the floor of the Oven as at 2
I. The flue or Bag applicable to one mode of constructing this Oven
K.Vent from Oven bottom without any elevated flue, applicable to
another mode of construction
above floor
G.4 Ground Plan and horizontal section of Oven
N°5. Half horizontal section of Oven
Nº 6. Half horisontal section of Oven
floor and with a arcular bay
-
above base with flues under the
instead of bags detached