IMPROVEMENTS IN THE MANUFACTURE OF FICTILE MATERIALS, APPLICABLE TO THE CUTTING, GRINDING, AND CLEANING OF GRAIN AND OTHER SUBSTANCES, AND ALSO TO THE FILTRATION PRO
Year: 1880

page_text: LETTERS PATENT to Gustav Adolph Buchholz, of Charlottenburg, in the
Empire of Germany, but temporarily of Holborn Viaduct, in the City of
London, Engineer, for an Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF FICTILE MATERIALS, APPLICABLE TO THE CUTTING, GRINDING, AND
CLEANING OF GRAIN AND OTHER SUBSTANCES, AND ALSO TO THE FILTRATION
PROVISIONAL SPECIFICATION left by the said Gustav Adolph Buchholz at
the Office of the Commissioners of Patents on the 17th August 1880.
GUSTAV ADOLPH BUCHHOLZ, of Charlottenburg, in the Empire of Germany, but
temporarily of Holborn Viaduct, in the City of London, Engineer. "IMPROVEMENTS
IN THE MANUFACTURE OF FICTILE MATERIALS, APPLICABLE TO THE CUTTING,
GRINDING, AND CLEANING OF GRAIN AND OTHER SUBSTANCES, AND ALSO TO THE
FILTRATION AND THE ABSORPTION OF LIQUIDS."
This Invention relates to improvements on the Invention for which I obtained
Letters Patent, bearing date January 21st, 1879, No. 250, for "Improvements in
the Manufacture of Factitious Millstones and other Grinding or Rubbing Surfaces."
In preparing the factitious millstones I described a mode or modes of producing
porous materials from the admixture of porcelain clay with seeds or other
carbonaceous material. Extended experience has shown that it is difficult to
ensure a good result, as the moulded material is liable to fall to pieces during the
drying, or crack during the firing of the same, owing to the resistance offered by
the carbon to the contraction of the clay, and it is also liable to fuse and attain
the quality of true porcelain, which is not desirable for the purposes of this
Invention.
To avoid these defects I proceed with the manufacture of my fictile porous
material (suitable, say, for mill stones) in the following manner :-
I take grain or seeds of suitable size, or small pieces of seived cork, or fine twigs
of soft wood reduced to small pieces by a chaff cutter and rounded in a pearl
barley mill, and having saturated the same in water or steam, so as to ensure the
swelling of the grain, seeds, or pieces, I mix therewith plastic clay, and mould the

page_text: mixture to the required shape, using slight pressure to consolidate the mixture.
The moulded material thus produced I dry first at the ordinary temperature of the
atmosphere and then by exposure in a heated chamber. When the moisture has
been driven off I submit the moulded material to a moderate furnace heat in order
to burn out the carbonaceous material and leave the clay in a porous state.
By thus carrying on the process I am enabled to provide for the gradual con-
traction of the clay, as the carboniferous material with which it is mixed contracts
more rapidly than the clay, and eventually disappears in the burning process.
The fictile material may at this stage be trued in a lathe or otherwise to restore
its form which it may have lost by warping or shrinkage, and it is then ready for
the final firing. This I carry on to within, say, 150° or 200° of the firing heat for
porcelain, and I then arrest the firing at or about the point where fusion commences.
The test for stopping the firing operation is that the material shall be slightly
absorbent of moisture when cool.
Should the material by any chance become over fired, it will be too hard for
grinding, but may be used with advantage for hulling grain.
When preparing the fictile material for a grindstone I take, say, poppy seed or
fine grains of cork, and having saturated them as before explained mix the same
carefully with the plastic clay, and mould, dry, and burn the compound as above
explained. I thus obtain a material with fine pores, and having shaped up the
factitious stone I fire it short of complete fusion, and thereby obtain a grindstone
of excellent quality, suitable not only for grinding metals, but also glass and other
hard substances.
"
Another application of my Invention consists in the production of a fictile
material which may be used as a lamp wick. In producing this material I proceed
by preference as follows:-I form bundles of fine vegetable fibres corresponding to
the form and size of the wick required, and dip the same into "slip or liquid
clay, and dry, burn, and fire as already explained. I thus obtain a porous material,
which will by capillary attraction draw up oil like a cotton wick for the supply of
fuel to kerosine and other lamps.
In some cases I may however give porosity to these wicks in the way described
for millstones.
Slabs or tubes of fictile material made as above explained I propose to use in
the construction of filter beds for filtering water and other liquids.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Gustav Adolph Buchholz in the Great Seal Patent Office on the
17th February 1881.
GUSTAV ADOLPH BUCHHOLZ, of Charlottenburg, in the Empire of Germany, but
temporarily of Holborn Viaduct, in the City of London, Engineer. "IMPROVEMENTS
IN THE MANUFACTURE OF FICTILE MATERIALS, APPLICABLE TO THE CUTTING,
GRINDING, AND CLEANING OF GRAIN AND OTHER SUBSTANCES, AND ALSO TO THE
FILTRATION AND THE ABSORPTION OF LIQUIDS."
This Invention relates to improvements on the Invention for which I obtained
Letters Patent, bearing date January Twenty first, One thousand eight hundred
and seventy nine, No. 250, for "Improvements in the Manufacture of Factitious
Millstones and other Grinding or Rubbing Surfaces."
In preparing the factitious millstones according to this Invention I described a
mode or modes of producing porous materials from the admixture of porcelain clay
with seeds or other carbonaceous material. Extended experience has shewn that
it is difficult to ensure a good result by the said mode of manufacture, as the
moulded material is liable to fall to pieces during the drying, or crack during the
firing of the same, owing to the resistance offered by the carbon to the contraction
of the clay. The moulded material is also liable to fuse, and attain the quality of
true porcelain, which is not desirable for the purposes of this Invention.
To avoid these defects I proceed with the manufacture of my fictile porous
material (say, for millstones) in the following manner :-
I take grain or seeds of suitable size, or small pieces of sieved cork, or fine twigs
of soft wood reduced to small pieces by a chaff cutter and rounded in a pearl-
barley mill, and having saturated the same with water, so as to ensure the swelling
of the grain, seeds, or pieces, I mix therewith plastic porcelain clay, and mould
the mixture to the required shape, using slight pressure to consolidate the mixture.
The moulded material thus produced I dry first at the ordinary temperature of the
atmosphere, and then by exposure in a heated chamber. When the moisture has
been driven off I submit the moulded material to a moderate furnace heat in order
to burn out the carbonaceous material and leave the clay in a porous state. By
thus carrying on the process I am enabled to provide for the gradual contraction
of the clay, as the saturated carboniferous material with which it is mixed contracts
more rapidly than the clay, and eventually disappears in the burning process.
The fictile moulded material may at this stage be trued in a lathe or otherwise
to restore the form which it may have partially lost by warping or shrinkage, and
it is then ready for the final firing.
This I carry on to within, say, one hundred degrees or two-hundred degrees of the
firing heat for porcelain, and I then arrest the firing at or about the point where
fusion commences. The test for stopping the firing operation is that the material
shall be slightly absorbent of moisture when cool.
Should the material by any chance become over fired it will not be so efficient
for use as a grinding surface, but it may be utilized with great advantage for
hulling grain.
It will be understood that the material while in a plastic state may be moulded
or pressed in the manner and by the means described in the Specification of my
before mentioned Patent.
When it is intended for use as a substitute for the ordinary millstones I cut the
moulded material on its face in the usual manner to form furrows for the delivery
of the ground material at the periphery of the mill as the same is produced.
I have found by extended experience that fictile material having pores throughout
its mass is applicable to a variety of uses other than those connected with milling

page_text: operations. Thus by a modification of my process of manufacture I am enabled to
produce a material which is applicable to the sharpening of tools and the grinding
of glass and other hard substances. It is also applicable when moulded into slabs
or cylinders, tubes, or other forms for use as a filtering material.
By a further modification I am enabled to produce a permanent wick suitable
for oil lamps.
When preparing the fictile material for grindstones I take, say, poppy seed or
fine grains of cork, and having saturated them as before explained, mix the same
carefully with the plastic clay, and mould, dry, and burn the compound as above
explained. I thus obtain a material with fine pores, and having shaped up the
factitious stone I fire it short of complete fusion, and thereby obtain a grindstone
of excellent quality, suitable not only for grinding metals, but also glass and other
hard substances.
In producing a fictile material which may be used as a lamp wick I proceed by
preference as follows:-
I form bundles of fine vegetable fibres corresponding to the form and size of the
wick required, and dip the same into "slip" or liquid porcelain clay, and dry, burn,
and fire as already explained. I thus obtain a porous material which will by
capillary attraction draw up oil like a cotton wick for the supply of oil to kerosine
and other lamps.
In some cases I may however give porosity to these wicks in the way described
for millstones.
Slabs, blocks, or tubes of fictile material made as above explained I propose to
use in the construction of filter beds for filtering water and other liquids.
Having now described the nature of my Invention of "Improvements in the
Manufacture of Fictile Materials, Applicable to the Cutting, Grinding, and Cleaning
of Grain and other Substances, and also to the Filtration and the Absorption of
Liquids," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I claim,―
First. In the manufacture of porous material for millstones, grindstones, and
filtering slabs or blocks the use of carbonaceous materials, such as those above
described, saturated with moisture, and mixed with the clay for the purpose of
rendering the same porous when burned, and providing against the cracking of the
material as it contracts under the action of the heat.
Second. In firing the moulded material (prepared as above explained) stopping
the action of the heat upon the material at or about the point where fusion
commences, for the purpose above explained.
Third. Manufacturing lamp wicks of porous fictile material, prepared in the
manner above described.
Fourth. The use of fictile materials produced as above described for the manu-
facture of grindstones and as filtering surfaces.
In witness whereof, I, the said Gustav Adolph Buchholz, have hereunto set my
hand and scal, the Seventeenth day of February, in the year of our Lord
One thousand eight hundred and eighty one.
GUSTAV ADOLPH BUCHHOLZ. (L.S.)