CERTAIN IMPROVEMENTS IN THE MANUFACTURE OF EARTHENWARE PASTES AND VITREOUS BODIES, AND ALSO A NEW COMPOSITION AND MATERIAL FOR THE SAME, WITH CERTAIN NEW MODES OF COM- BINATION THEREOF, WHICH IMPROVEMENTS, COMPOSITIONS, AND COMBINATION ARE APPLICABLE TO THE MANUFACTURE OF EARTHENWARE PASTES, VITREOUS BODIES, SLABS, TILES, AND PAVEMENT, AND VARIOUS OTHER USEFUL AND ORNAMENTAL PUR- POSES
Year: 1845

page_text: TO ALL TO WHOM' THESE PRESENTS SHALL COME, we GEORGE
SKINNER, of Stockton-on-Tees, in the County of Durham, Merchant, and JOHN
WHALLEY, of South Stockton-on-Tees, in the County of York, Earthenware
Manufacturer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twentieth day of November, in the ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said George Skinner and John Whalley, our exors, admors, and assigns,
Her especial license, full power, sole privilege and. authority, that we, the
said George Skinner and John Whalley, our exors, adñiors, and assigns,
should at any time agree with, and no others, from time to time and at
all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England and Wales, and Town
of Berwick-upon-Tweed, our Invention for "CERTAIN IMPROVEMENTS IN THE
MANUFACTURE OF EARTHENWARE PASTES AND VITREOUS BODIES, AND ALSO A NEW
COMPOSITION AND MATERIAL FOR THE SAME, WITH CERTAIN NEW MODES OF COM-
BINATION THEREOF, WHICH IMPROVEMENTS, COMPOSITIONS, AND COMBINATION ARE
APPLICABLE TO THE MANUFACTURE OF EARTHENWARE PASTES, VITREOUS BODIES,
SLABS, TILES, AND PAVEMENT, AND VARIOUS OTHER USEFUL AND ORNAMENTAL PUR-
POSES;" in which Letters Patent there is contained a proviso, that we, the said
George Skinner and John Whalley, or one of us, shall cause a particular
description of the nature of our said Invention, and in what manner the same is

page_text: to be performed, to be enrolled in Her Majesty's High Court of Chancery
within six calendar months next immediately after the date of the said now
reciting Letters Patent, as in and by the same, reference being had thereto,
will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, we, the said
George Skinner and John Whalley, do hereby declare that the nature of our
said Invention, and the manner in which the same is to be performed, are
particularly described in and by this present instrument in writing under our
hands and seals, in the words herein-after written.
Before, however, we proceed to describe the particulars of our said Invention,
it may be proper to state the objects of it are,-
Firstly, for the use and manufacture of a new composition and material,
being a combination of chalk or carbonate of lime and silica in certain propor-
tions, with other ingredients herein-after named, to form vitreous pastes, which
we call artifical marble or marble pastes.
Secondly, to lessen the expense and improve the qualities of earthenware
and pottery by the addition of this new composition, viz., of chalk or carbonate
of lime and silica in certain proportions with other ingredients herein-after
named, and by which a whiter earthenware can be made without the use of
cobolt as a stain, and with the use of a less quantity of ground silica.
Thirdly, to effect the glazing of earthenware or pottery without the use of
lead or any other deleterious materials, and without the use of acids, alkalies,
or other expensive materials.
And, fourthly, the application of such vitreous pastes, articifial marble, or
marble pastes and glazes, when prepared as aforesaid, to the manufacture of
certain known and useful articles.
The advantages of our Invention as are follows:-
With respect to the first part thereof, by the use of the composition of
chalk or carbonate of lime and silica in the proportions, and with the other
materials herein-after mentioned and described under the heads No. 1 and No. 2,
and which relate to this portion of our said Invention, we produce vitreous or
marble pastes, which, when burnt, resemble marble, and with properties more
durable. It is vitreous from fusion, excludes moisture so as to be unaffected
by atmospheric changes, and will bear a very high degree of heat without
splitting or cracking; it can be ground and polished, and will combine with
many colouring metallic oxides, such as oxide of chrome, &c., which, like dies,
pervade the mass, and produce the most delicate tints, or strong, clear, and
distinct enamel colours, and which can be worked in the mass or in relievo, or
in any other suitable manner, and being vitreous from fusion, abrasion, or

page_text: wear, cannot destroy or alter its tint; having no artificial glaze on its surface,
it maintains its original appearance through the entire mass. These pastes,
when prepared and worked up into shape can be painted or printed and
finished, if so desired, by one process of firing
With respect to the second part thereof, by the use of the composition of
chalk or carbonate of lime and silica in the proportions and with the other
materials herein-after mentioned and described under the heads No. 3, No. 4,
and No. 5, and which relate to this portion of our said Invention, we produce
a whiter earthenware without the use of cobalt stain, and also with the addi-
tion of a less quantity of silica than is usually used in the manufacture of
carthenware bodies, thereby effecting a considerable saving in expence of the
composition of such bodies, and rendering them better adapted to receive the
glaze in their biscuit state. It also retains its form and whiteness in the
degree of heat requisite to vitrify the glaze on its surface, and thereby secures
an increased brilliancy to the fritted glaze now generally used by potters, and
that either for the white or printed earthenware.
With respect to the third part thereof, the deleterious effect of the use of
the compounds of lead has long been known, not only as respects the health of
the workmen, but also that the articles made, and to which it is added are
liable to be acted on by acids and other corrosive matters. Our compositions,
prepared as herein-after described under the heads No 6 and. No. 7, and which
relate to this portion of our said Invention, enable us to do away with the use
of lead and other deleterious materials in the manufacture of earthenware and
pottery, and also in the glazes used for the same; for by using in certain
proportions as we do, only such materials as enter into the composition of the
bodies of pastes, earthenware, and pottery prepared after our methods, we can
prepare beautiful and most durable glazes at much less expense without the
uso of any of the compounds of lead, acids, alkalies, or any of the salts or other
expensive materials, and that by simply dipping the biscuit or body, and firing
in the usual manner, but with a stronger degree of heat.
We shall now describe the new composition and material, the modes or
methods we adopt in preparing and mixing the same, together with the several
proportions of the materials used under the following heads:-The first head,
No. 1, a marble paste; the second, No. 2, another marble paste; the third,
No. 3, a semi-vitrious or china body; the fourth, No. 4, a white earthenware
body; the fifth, No. 5, a porous earthenware body or paste; the sixth, No. 6,
à composition for a glaze without lead; the seventh and last, another compo-
sition for a glaze without lead. The modes or methods we adopt in preparing
and mixing all the materials used for the composition relating to each bead

page_text: above-named, and herein-after particularly described, are as follows:-They
'must all severally be reduced to powder, mixed with water, and brought into
what is known as the state of pulp or slip, and afterwards be sifted, the same
as the preparation of clays and other materials now used by potters usually are;
these pulps or slips must then be brought to a given density or weight, varying
from twenty-four ounces to thirty-two ounces to the imperial pint, or in other
suitable proportions, but always in some relative proportion to the object
desired. These, when reduced and brought to a suitable given density or
weight, as aforesaid, are either severally mixed and combined in the proportions
herein-after mentioned, or they can as they are prepared be treated as pulps
and slips usually are by potters, and then mixed together when they are
required for use; if, however, they are required at once for use, having been
mixed and combined in the manner herein-after mentioned, they are to be
sifted or passed through a fine silk, lawn, or other suitable scieve, and it is pre-
ferable after they have been once sifted to sift them a second time, whareby
the mechanical combination will be more complete; after they have been
sifted as aforesaid, they are subjected to the mode of treatment usually adopted
by potters in preparing materials from pulps or slips prior to working up, and
which are well known, and the pastes or bodies when ready are worked up in
the usual manner, and are moulded and applied in a variety of shapes and
forms, and which are also well known to potters, and therefore unnecessary to
particularize. When they are so worked up, the articles into which they are
formed are placed in seggars, and the seggars put into the potters biscuit kiln
which is raised to a proper degree of heat, usually from 45 to 60 of Wedge-
wood. The degree of heat applied will, however, depend upon the particular
proportions of the materials used in the compositions, and also whether the
articles being made are required for any specific object. The degree of heat
is best ascertained by trial peices placed in the biscuit kiln accessible to the
workmen at any time, which trial pieces should be of the same composition as
those being fired, and which mode of ascertaining the degree of. heat by trial
pieces is well known to potters. The materials we use to prepare our com-
position and material; and the proportions in which they are mixed, are as
follows, all of which must be in a state of pulp or slip and at a given density,
as before mentioned.
No. 1. Marble paste.-One pint of silica, flint, or silex, in pulp, thirty
ounces to the imperial pint; one pint of chalk or carbonate of lime, twenty-
four ounces to the imperial pint; one pint of Cornwall stone, thirty-two ounces
to the imperial pint; one pint of china clay, twenty-four ounces to the imperial
pint; one pint of ball clay, twenty-four ounces to the imperial pint.

page_text: No. 2. Marble paste.-Three pints of chalk or carbonate of lime, twenty-
eight ounces to the imperial pint; two pints of silica, flint, or silex, thirty-two
ounces to the imperial pint; three pints of china clay, twenty-four ounces to the
imperial pint; two pints of Cornwall stone, thirty-two ounces to the imperial
pint; two pints of ball clay slip, twenty-four ounces to the imperial pint.
The vitreous or marble pastes resulting from these compositions may be tinted
any desired colour or shade by the use of metallic oxides prepared and used
as they usually are in potteries for such purposes; for instance, if cobalt is
added in proper proportion; a blue marble paste will be the result on their
proper union by means of heat, and a green colour under the same circum-
stances on the addition of oxide of chrome, &c., &c.
No. 3. A semi-vitreous or china body.-Three pints of chalk or carbonate-
of lime, thirty ounces to the imperial pint; four pints of silica, silex, or flint,
thirty-two ounces to the imperial pint; eight pints of china clay, twenty-four
ounces to the imperial pint; six pints of ball clay, twenty-four ounces to the
imperial pint. If required more vitreous, add also one pint of felspar, twenty-
four ounces to the imperial pint.
No. 4. A white earthenware body.-Three pints of silica, flint, or silex, thirty-
two ounces to the imperial pint; two pints of chalk or carbonate of lime, twenty-
eight ounces to the imperial pint; ten pints of china clay, twenty-four ounces
to the imperial pint; five pints of ball clay, twenty-four ounces to the imperial
pint; one pint of helspar, or sulphate of barytes, thirty-two ounces to the imperial
pint. If desired whiter, use fifteen pints of china clay instead of ten, and no
ball clay.
No. 5. Porous earthenware body or paste.-Three pints of silica, flint, or
silex, thirty-two ounces to the imperial pint; two pints of chalk or carbonate
of lime, twenty-eight ounces to the imperial pint; five pints of ball clay, twenty-
four ounces to the imperial pint; ten pints of china clay, twenty-four ounces
to the imperial pint. The purity, quality, and whiteness of these several
compounds depend upon the quality and purity of the materials used in their
composition or combination. All these several mixtures and compositions
may be called bodies or pastes for distinction. The composition No. 1 and
No. 2 do not require to be glazed; No. 3, No. 4, and No. 5 can be glazed,
without the assistance of lead or any of its compounds, and that by glazės
formed principally of the same or like materials of which such bodies or
pastes are compounded, but mixed in different proportions. We wish it how-
ever to be understood, that if it is required, any of the compounds of lead and
other materials usually used in the manufacture of glazes for pottery or china
of any description can be used on the bodies or combined with the glazes we

page_text: employ, but we do not think it advisable to do so unless for printed ware; and
also that the glazes we prepare can be used to glaze any description of pottery,
earthenware, or china, made of the usual materials employed for such
purpose.
The glazes we prepare, and which composition we claim as part of our
Invention, are prepared as follows, the materials of which are all previously
reduced and prepared in the same manner as the powder, pulp, and slips for
the compositions herein-before mentioned for the bodies or pastes :-
No. 6. A composition for a glaze without lead.-Three pints of felspar,
twenty-eight ounces to the imperial pint; one ditto of chalk or carbonate of
lime, twenty-eight ounces to ditto.
No. 7. Another composition for a glaze without lead.-Two pints of chalk
or carbonate of lime, twenty-eight ounces to imperial pint; one ditto of silica,
flint, or silex, thirty-two ounces to ditto; onc ditto of Cornwall stone, thirty-
two ounces to ditto; one ditto of china clay, twenty-four ounces to ditto; one
<litto of ball clay, twenty-four ounces to ditto; four ditto of felspar, twenty-
eight ounces to ditto.
The mode or method in which we use these glazes is as follows:- Any
article of pottery or china having been prepared in the usual manner by
moulding or otherwise of any of the compositions No. 3, 4, and 5, herein-
before described, is placed in the kiln and brought to the biscuit slate.
Either of the above-mentioned glazes having been previously prepared as
aforesaid, the article so brought into the biscuit state is then taken out
and dipped into it, in the same manner as is usually done in dipping
common earthenware for glazing, and which is well understood by potters,
and it is afterwards placed in the kiln and fired with a suitable but greater
degree of beat then is used in bringing it into the biscuit state, and
which can be ascertained exactly by the trial pieces as aforesaid, and it
is allowed to remain there a proper time, usually about twenty-four to
thirty hours, but depending on the size of the kiln or until properly
finished, as can be ascertained by examinations from time to time by the
trial pieces. The two glazes herein-before described require the addition
of a small portion of fine ground cobalt as a stain, say about two ounces to
four hundred pounds of either composition of the glazes aforesaid, and by
which will be produced a beautiful porcelain and earthenware glaze, and much
superior to those compounded of lead and borax now generally employed.
Should a glaze be required more transparent for printed and painted pottery,
china, or earthenware than those we have described, it can be made by the
addition of any desirable quantity of the following fritt to these glazes in a

page_text: small proportion, which proportions will range from one proportion of fritt to
two proportions of either of the glazes No. 6 or No. 7, and so on to ten
proportions of No. 6 or No. 7. The proportions of such fritt are as follows:-
One hundred pounds of ground silica, silex, or flint in dust, seventy pounds of
soda, sixty pounds of boracic acid, fifty pounds of whiting. The materials of
this fritt must be mixed together, and may be put into a fritt kiln now used
by potters, or in seggars lined with silica or flint, and submitted to the heat of
the potters glost oven for a suitable time, usually twenty hours; it is then
taken out and allowed to cool. It is afterwards reduced to powder, pulp, or
slip in the manner herein-before mentioned, and then added in any requisite
proportions to either of the glazes No. 6 or No. 7. The compositions and
combinations herein-before mentioned, No. 1 and No. 2, can be manufactured
into a variety of articles, and are applicable to a variety of purposes, amongst
which
may be mentioned the following:-White and coloured imitation marbles,
mosaic and encaustic tiles and slabs for architectural decorations, internally or
externally, for monumental inscriptions, designation plates for streets or doors,
for sign boards, labels, buttons, letters, either by inlaying or printing, also for
tops for furniture, mortars, laboratory memorandums, for slabs of fire-places,
weights, and other purposes. The compositions No. 3, No. 4, and No. 5 can
be manufactured into a variety of articles of pottery, china, and earthenware;
and applied to other useful purposes.
Having thus described the nature of our said Invention and the manner in
which we perform the same, it must be understood that although we have
laid down certain directions, proportions, and methods as to how the several
compositions, materials, glazes, and articles are to be prepared and treated,
yet we do not confine ourselves strictly thereto, as it is obvious such materials,
glazes, and articles can be prepared, varied, and treated in a variety of other
ways and proportions. We have therefore described those combinations, com-
positions, materials, glazes, and articles, as well as the mode or methods of
combination and operation, which we consider best, and by which this
Invention can be most effectually carried into operation; but we do claim,―
Firstly, the use and combination of chalk or carbonate of lime in union
with silica, flint, or silex, and the compounding of these substances, when
prepared as aforesaid or in any other suitable manner, in the proportions
herein-before mentioned or in any other suitable proportion or quantities,
with all or any of the other substances or materials herein-before named
and described, or other suitable substance or substances, for the purpose of
forming vitreous pastes, artificial marble, marble pastes, bodies, and glazes
for any of the articles or purposes herein-before mentioned, or other similar

page_text: useful articles or purposes, or for pottery, china, earthenware, or other such
like vitreous or vitrifiable bodies.
And lastly, we claim the use and preparation of the compositions, pastes,
bodies, and glazes herein-before mentioned, made in the proportion of the
materials or substances and prepared and treated in the peculiar modes or
methods herein-before stated. But we do not confine ourselves thereto, or to
the precise forms, proportions, or details shewn, provided the peculiar cha-
racter of any or either part of our said Invention be used, retained, or brought
into operation.
In witness whereof, the said George Skinner and John Whalley have
hereunto set their hand and seals, this Sixteenth day of May, in the
year of our Lord One thousand eight hundred and forty-six.
GEORGE (L.s.) SKINNER.
JOHN
(L.S.) WHALLEY.
AND BE IT REMEMBERED, that on the Sixteenth day of May, in the
year of our Lord 1846, the aforesaid George Skinner and John Whalley came
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.
Enrolled. the Twentieth day of May, in the year of our Lord One
thousand eight hundred and forty-six.