IMPROVEMENTS IN THE MANUFACTURE OF PORCELAIN, CHINA, POTTERY, AND EARTHENWARE, AND WHICH IMPROVEMENTS ARE ALSO IN PART APPLICABLE TO THE MANUFACTURE OF PAPER, AND TO THE PREPARATION OF CERTAIN PIGMENTS OR PAINTERS COLORS
Year: 1843

page_text: BROWN, of the City of Glasgow, Merchant, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Third day of June, in the sixth year of Her reign, did, for Her-
self, Her heirs and successors, give and grant unto me, the said William
Brown, Her especial licence, that I, the said William Brown, my exors,
admors, and assigns, or such others as I, the said William Brown, my exors,
admors, and assigns, should at any 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 that part of the United
Kingdom of Great Britain and Ireland called England, the Dominion of
Wales, and Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF PORCELAIN, CHINA, POTTERY, AND EARTHENWARE, AND
WHICH IMPROVEMENTS ARE ALSO IN PART APPLICABLE TO THE MANUFACTURE OF PAPER,
AND TO THE PREPARATION OF CERTAIN PIGMENTS OR PAINTERS COLORS;" in which
Letters Patent there is 'contained a proviso that I, the said William
Brown, should cause a particular description of the nature of my said Inven-
tion, and in what manner the same is to be performed, to be enrolled in Her
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the now reciting Letters Patent, as in and by
the same, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Brown, do hereby declare that the nature of my said Invention, and

page_text: the manner of performing the same, are particularly ascertained and described
as follows:-
And, first, as to my improvements in the manufacture of porcelain, china,
pottery, and earthenware, my improvements commence at that stage of the
ordinary process of manufacturing porcelain, china, pottery, and earthenware
out of the substances or materials of which such ware, whether of a coarser
or finer quality, is usually manufactured, when their levigation or grinding and
mixing is finished, in which state the substance or liquid is usually called
'slip" by the workmen. I run this substance or liquid into a vessel of
convenient and sufficient size and strength to resist a pressure of at least one
hundred pounds on the square inch. This vessel must be air-tight, and have
an air pump and condensing pump attached to it of the usual construction,
or such other apparatus as may be conveniently used for the purpose of
exhausting the air from and admitting a pressure into such vessel. The vessel
must also be furnished with a stirrer or agitator to be worked by hand or
power, and passing through a stuffing box, so as to prevent the subsidence of
the materials, and keep them in a mixed state. I then proceed to abstract
the air as completely as possible from the vessel, working the agitator at the
same time until as good a vacuum as the apparatus will produce is maintained
for the space of half an hour. I then admit the air, and work the condensing
pump, forcing air upon the surface of the solution until I obtain a pressure of
from fifty to one hundred pounds on the square inch. The pressure is then
withdrawn, and the liquid run off into tubs by a pipe and stopcock at the
bottom of the vessel, from which it is carried and poured into filters, when the
water is allowed to run away until the substance or materials acquire sufficient
consistence, when it is carried to a stove and cried by heat, or on chalks until
it becomes sufficiently dry to be worked by hand, or, in other words, until it
acquires the same degree of consistency which is usually given to these mate-
rials in the pan, after which operation the manufacture is completed in the
usual way. By this improved process a greater degree of solidity and strength
is given to the ware than is attained and acquired by the ordinary mode.
Besides which, the process of boiling may be omitted altogether, by adopting
that of filtering and stoving in its place, by which means a further saving of
expence is effected. The pressure may be applied without the previous
abstraction of the air, or the air may be abstracted without afterwards apply-
ing the pressures; but I prefer both the abstraction of the air and the
application of the pressure.
Secondly, as to my improvements in the manufacture of paper, I provide
an air-tight vessel fitted with an air pump, condensing pump, agitator, and

page_text: stopcocks of a similar construction to that which has been already described.
I put into this vessel the pulp which has been prepared by the usual methods
for making paper of any description at that stage of the ordinary process when
it has been washed and bleached or cleansed, and is collected in the tun or
"stuff chest," in order to be run out upon the frames and formed into paper.
I prefer this stage of the ordinary process at which to apply my improve-
ments; but they are applicable at any stage of the preparatory process after
the materials have been reduced into a pulp. From this pulp so placed in
the air-tight vessel, I extract the greater portion of the air, making the best
vacuum that is practicable, keeping the pulp stirred by means of the agitator,
and maintaining the vacuum for at least half an hour. I then allow the air
to enter the vessel, and attach the condensing pump to the vessel, and work it
until a pressure is attained of from fifty to one hundred pounds on the square
inch. When the operation is finished, I discharge the pulp into the tun or
stuff chest, from whence it is by the ordinary process made to flow out upon
the frames, and I then proceed to complete the manufacture in the usual way.
By means of my improved process, as above described, paper and pasteboard
are made closer and firmer in the texture, and of greater solidity, strength,
and durability, than by the ordinary method. In this case also the air may be
abstracted without applying the pressure, or the pressure may be applied with-
out the previous abstraction of the air; but I prefer making use of both the
abstraction and the pressure.
Thirdly, as to my improvements in certain pigments or painters colors.
The pigments or painters colors to which my improvements apply are those
which are manufactured from single substances, and not compounded of
various materials or any pigments whatever, the preparation or manufacture
of which have been previously completed. I place such pigments or painters
colors, after they have been reduced to powder and mixed with water, so as to
produce a convenient consistency, into an air-tight vessel fitted with an air
pump, condensing pump, agitator, and stopcocks of a similar construction to
that which has been already described. I then abstract the air, or as great a
portion of it as is practicable, keeping the matter stirred by the agitator, and
maintaining the vacuum for at least half an hour. I then admit the air, and
put on the condensing pump, and raise the pressure from eighty to one hun-
dred pounds on the square inch. I then discharge the matter into suitable
tubs, and filter and dry it in the usual way. By this improved process white
lead, Dutch lead, Paris white, Venetian red, and other pigments which are
manufactured from single substances, and not compounded of various mate-
rials, are improved in body or solidity; but the pressure may be conveniently

page_text: applied, not only to these pigments separately, but to two
pigments separately, but to two or more of them
together. In this case also the air may be abstracted without applying the
pressure, or the pressure may be applied without the previous abstraction of
the air; but I prefer making use of both the abstraction and pressure.
In the manufacture, therefore, of all the several materials or substances
before described or referred to, I claim as my Invention the process of abstract-
ing the air as much as possible from the particular material or substance
under operation, whether the pressure shall be subsequently applied or not;
also, the process of agitating the material or substance during the abstraction
of the air; also, the process of applying the pressure of the atmosphere or
any other mode of pressure by fluids. to the particular material or substance
under operation, whether the air shall have been previously abstracted or not;
and, lastly, the application of this process. by means of the vessel and apparatus
before described, or by any other convenient or suitable apparatus whereby
such process can be used and carried out; but I do not claim the separate
parts or details of the apparatus. And such my Invention being, to the best
of my knowledge and belief, entirely new, and never before used within that
part of Her Majesty's United Kingdom of Great Britain and Ireland called
England, the Dominion of Wales, and Town of Berwick-upon-Tweed, I do
hereby declare this to be my Specification of the same, and that I do verily
believe this my said Specification doth comply fully, and in all respects with-
out reserve or disguise, with the proviso in the herein-before in part recited
Letters Patent; wherefore I claim to maintain exclusive right and privilege to
my said Invention.
In witness whereof, I, the said William Brown, have hereunto set my
hand and seal, the
day of November, One thousand eight
hundred and forty-three.