A NEW POROUS MATERIAL FOR FILTERS AND OTHER LIKE ARTICLES, AND FOR CERTAIN MODIFICATIONS FOR IMPROVEMENTS IN THE MANUFACTURE OF THE MATERIAL, WHEREBY IT IS ADAPTED TO THE FORMATION OF VESSELS OF CAPACITY, TO BE EMPLOYED. AS A CEMENT, AS A WATER AND ACID-PROOF LINING, AS A PRESERVATIVE COATING AND AS A SUBSTITUTE FOR STONE AND EARTHENWARE
Year: 1856

page_text: LETTERS PATENT to William Petrie of Woolwich, in the County of Kent,
Civil Engineer, for the Invention of "A NEW POROUS MATERIAL FOR
FILTERS AND OTHER LIKE ARTICLES, AND FOR CERTAIN MODIFICATIONS FOR
IMPROVEMENTS IN THE MANUFACTURE OF THE MATERIAL, WHEREBY IT IS
ADAPTED TO THE FORMATION OF VESSELS OF CAPACITY, TO BE EMPLOYED. AS A
CEMENT, AS A WATER AND ACID-PROOF LINING, AS A PRESERVATIVE COATING
AND AS A SUBSTITUTE FOR STONE AND EARTHENWARE"
Sealed the 19th December 1856, and dated the 12th July 1856.
PROVISIONAL SPECIFICATION left by the said William Petrie at
the Office of the Commissioners of Patents, with his Petition, on the
12th July 1856.
I, WILLIAM PETRIE, of Woolwich, in the County of Kent, Civil Engineer,
do hereby declare the nature of the said Invention for "A NEW POROUS
MATERIAL FOR FILTERS AND OTHER LIKE ARTICLES, AND FOR CERTAIN MODIFICATIONS
OR IMPROVEMENTS IN THE MANUFACTURE OF THE MATERIAL, WHEREBY IT IS ADAPTED
TO THE FORMATION OF VESSELS OF CAPACITY, TO BE EMPLOYED AS A CEMENT, AS A
WATER AND ACID-PROOP LINING, AS A PRESERVATIVE COATING, AND AS A SUBSTITUTE
FOR STONE AND EARTHENWARE to be as follows:
For filters and porous articles I take silicious sand, having its grains of us
nearly as may be an uniform size; fine or coarse, according to the purpose
intended. This is well dried by heat, and then sifted with about a quarter of
its weight of powdered sulphur, or of what I shall, for brevity in this Speci
fication, call-compound sulphur, that is to say, sulphur mixed with silicious

page_text: dust reduced to an impalpable powder, containing grains of all other sizes up
to about of the diameter of the grains of which the porous material is to
be formed. There are several known ways of obtaining this kind of dust; or
instead of it, I take dust of clay, preferred to be well baked, that is anhydrous.
This dust, silicious or argilaceous, I mix with the sulphur in such proportion
that it shall make a material which, when heated, is perceptibly as liquid as
sulphur alone would be. The said sand and this matter, either sulphur or the
compound sulphur, I rub and stir in a shallow iron dish; which may be
several feet square, heated by a fire beneath so hot as just to cause the sulphur
to ignite, and as it becomes ready for use, by. thorough intermixture of a con-
sistence like damp sand, I push it off into a similar dish adjoining, kept by
means of a slow fire at a temperature a little, below that of ignition, or rather
at the temperature at which sulphur attains its greatest degree of viscosity
after it has turned brown by heat, and here also it is kept rubbed and stirred.
It is thence thrown in a mass on or into a mould of the desired shape (made
of cast iron, or lead, or loam, &c.), and quickly pressed or rammed into the
shape by a rammer, or by forcing another part of the mould upon or against
the first part, as is well understood; cold water is then immediately thrown
over the moulded material, so as to sink through its pores.
Instead of applying the cold water, another plan, and which secures the
most perfect.porosity with the finest texture,is to cast it with a "tail" beneath
of the same material, into which the surplus sulphur can settle, and which can
be cut off afterwards. The degree of porosity it is best to regulate by the
fineness of the grain of the sand. It may be also regulated by the quantity of
sulpliur or of compound sulphur used, and by the time it is kept in a heated
state. For solid material, proof against water or sulphuric or nitric acid, &c.,
the sand is to be of grains as much as possible of mixed sizes, from the finest
powder (or powder nearlyas fine as the largest grains in the compound sulphur
when this is employed) up to such a size of sand, or pebbles, or stones, as the
degree of coarseness of the article may allow. When smoothness of the
surface is not an object, the largest sizes in the composition may be equal to
half the thickness of the material. This variety of sizes, when grains of each
size exist in about such proportions as will fill all the interstices of their own
size between the larger grains, increases the strength, and diminishes the
brittleness of the material, and greatly economizes the sulphur, besides dimi-
nishing any little exhalation or evaporation of sulphur when the article is in use
with warmth applied, and giving ita somewhat better resistance to destruction
by heat. The same advantages attend the use of the compound sulphur,
instead of plain sulphur, in forming either the porous or the solid material.

page_text: This mixture of various sizes of silicious matter, first heated to about the
igniting point of sulphur, is incorporated by thoroughly stirring with plain,
or preferably with the compound sulphur,in such proportion as will just render
the mass sufficiently liquid to flow into the mould. The proportion cannot be
stated numerically, as it depends on the degree of variety in the sizes of the
grains of the solid matter. There are several advantages in beating the com-
position to the degree just stated, and using it at that temperature. The
composition should be well stirred while being used, and cast into moulds with
a head in which any surplus sulphur will collect as the material cools, and the
sulphur acquires its more liquid condition just previously to its finally solidify-
ing. The composition may also be used as a cement for fastening metal into
stone, or for any similar purpose, and for coating metal, or wood, or stone, by
dipping or otherwise, to preserve it from external influences; by properly adapt-
ing the size and character of its grains, grindstones and similar articles may be
made of it. It may be used to make flagstones for paving, or to lay down and
be spread, like asphalt, to form paths, or to line tanks and other receptacles
for liquids. The articles manufactured may be afterwards trimmed or brought
into more perfect shape by the use of a rasp or a hot iron, confined or not with
scraping off or smoothing down and pressing into shape the portions softened
by the hot iron.
For cheap material, such as concrete for hydraulic works, or for other
buildings, or for paths, little expense need be incurred in selecting the quality
of the stones and sand; but for chemical ware the materials should be such
as granite or porphyry, or better silicious matter, as quartz or flint.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Petrie in the Great Seal Patent Office on the
12th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PETRIE, of Woolwich, in the County of Kent, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of July, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Petrie, Her special licence that I, the said William Petrie, my
executors, administrators, and assigns, or such others as I, the said William
Petrie, my executors, administrators, and assigns, should at any time agree

page_text: 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, aud Isle of Man, an Invention for "A NEW POROUS
MATERIAL FOR FILTERS AND OTHER LIKE ARTICLES, AND FOR CERTAIN MODIFICA-
TION OR IMPROVEMENTS IN THE MANUFACTURE OF THE MATERIAL, WHEREBY IT IS
ADAPTED TO THE FORMATION OF VESSELS OF CAPACITY, TO BE EMPLOYED AS A CEMENT,
AS A WATER AND ACID-PROOF LINING, AS A PRESERVATIVE COATING, AND AS A SUI-
STITUTE FOR STONE AND EARTHENWARE," upon the condition (amongst others)
that I, the said William Petrie, 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 William Petrie, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement thereof, that is to say:--
For filters and porous articles I fake silicious sand, having its grains of as
nearly as may be an uniform size, fine or coarse, according to the purpose
intended. This sand is well dried by heat, and mixed with about a quarter of
its weight of powdered sulphur. I rub and stir this mixture in a shallow iron
or other suitable dish, heated by a fire beneath to such a temperature as will
nearly cause the sulphur to ignite, and when the ingredients are thoroughly
intermixed, and become of a consistence like damp sand, I push the mixture
off into a similar dish adjoining, kept at a lower temperature, but sufficiently
hot to preserve well the allotropic or brown and viscous state of the sulphur
(which ceases at a lower temperature before it finally solidifies), and in which
also it is rubbed and stirred. The mixture thus treated is thence thrown in a
mass on or into a mould of the desired shape (made of cast iron, or lead, or
loam, &c.), and quickly pressed into shape a light rammer, or by forcing
another part of the mould upon or against the first part, as is well understood
in similar arts; cold water is then immediately thrown over the moulded
material while still in the mould, so as to sink through its pores. Care must
be taken not to apply the water too freely at first, or the material might be
blown
I form holes or
up by an excess of steam formed in its interior.
apertures in the under side of the mould to allow the water to percolate.
Instead of applying cold water, another plan is to cast the substance with "a

page_text: tail" beneath, of the same or similar material, into which the surplus sulphur
may settle, and which can be cut off afterwards. This plan is more applicable
to articles of some forms rather than others; it secures freer porosity, and when
the material is of fine texture, this plan is the more desirable. The degree of
porosity is best regulated by the fineness of the grain of the sand. It may
also be regulated by the quantity of sulphur used, and by the time the mixture
is kept in a heated state.
In place of sulphur in the above described processes, I sometimes use what
I call compound sulphur, which I form by taking clay (white China clay being
preferred), which I first dry at a temperature just not so high as to hinder the
thorough pulverization of the clay, which is next pulverized. I then bake this
clay powder at such a temperature as to render it anhydrous, and incorporate
and thoroughly stir and melt it with powdered sulphur, in such proportions as
to make a sufficiently liquid mass for the intended purpose. Instead of clay, I
use in some cases an impalpable powder of silicious or hard carbonaceous
matter, or Imix these with the clay, and-I-do-not-limit myself to the use of these
materials-only-in-forming the-compound-sulphur.
The composition, whether it be the porous material or the compound sulphur
alone, or the solid material herein-after described, is improved, for inany
purposes, by the addition of a small proportion (preferably the twentieth, or
between one per cent. and ten per cent.), of resinous matter, as pitch, wax,
gutta percha, or shell-lac, which should be first thoroughly incorporated with
the sand or powder at a temperature which will secure the fusion of the former.
constituent, and by adding the sulphur afterwards; but the temperature must
never be raised so high as to decompose the materials used.
For solid material, proof against water and sulphuric and nitric acids, &c.,
the sand used has its grains of mixed sizes, from the finest powder (or powder
nearly as fine as the largest grains in the compound sulphur, when this is
employed), up to such a size of sand, or pebbles, or stones as the degree of
intended coarseness of the article may allow; but I consider it preferable to
have the largest pieces of material only about one-eighth of the thickness of
the mass when manufactured.
This variety of sizes (when the grains of each size exist in about such pro-
portions as will fill all the interstices of their own size between the larger
grains) increases the strength and efficiency of the material, and economizes
the sulphur, besides diminishing any exhalation of sulphur from warmth when
the article is in use, and giving it a somewhat better resistance to destruction
by heat. Similar advantages attend the use of the compound sulphur, instead
of plain sulphur, in forming either the porous or the solid material.

page_text: The solid matter in grains of these various sizes, is put into a pot, preferably
of iron, and heated nearly to the degree of ignition of sulphur. And in cases
when it is intended to mix with it the aforesaid resinous matter, the mass must
first be allowed to cool sufficiently, and then be mixed as aforesaid, the previous
heating being beneficial. It is then incorporated by continued stirring with
plain or preferably with the compound sulphur,insuch proportion as will render
it just sufficiently liquid (to cast in the mould, or to use in the other ways to
be mentioned), when it has cooled down to the temperature of greatest fluidity
of sulphur.
There are several advantages in heating the composition in process of manu-
facture to the degree above stated, and it should be kept well stirred while
being used; and the moulds should be so constructed that the composition
can be pressed into them as viscous a state as may be, when the form does
not necessitate the use of a fluid composition which needs more sulphur. And
the casting, especially in the latter case, should be made with "a head," in
which any surplus sulphur will collect as the material cools, and the sulpuur
acquires its most liquid state just previously to its finally solidifying. I thus
make chemical apparatus, as vessels, pipes, and shoots or troughs of it; for
which purpose it possesses the peculiar advantage that it may be joined,
repaired, or altered at any time, and in any required manner, by means of hot
irons of suitable shapes; I make also drain pipes, roofing tiles, tombstones,
paving stones, porous or not, and blocks for architectural purposes, hollow or
solid, and ornamented or plain, which are unaffected by chemical or atmo-
splieric agencies, and almost any kind of vessel or other article for which stone
or stoneware, or cathenware is used; and by properly adapting the size and
character of its grains, I make very cheap and useful grindstones, &c.
I use this composition also as a cement for building and for fastening metal
work into stone, and for all similar purposes, and for coating metal, wood, and
stone, which for this purpose should be rough and warmed; also for lining
tanks, &c., and for forming the surface of paths and roads, porous or not, and
roofs and other similar purposes. In these cases the articles may be dipped
into the melted composition, or it may be poured and spread upon them. The
articles manufactured, or the composition employed, maybe afterwards trimmed
or brought into more perfect shape by the use of arasp or hot iron, combined or
not with scraping off or smoothing down, and pressing into shape the portions
softened by the hot iron.
I do not confine myself to the use of silicious or hard carbonaceous matter
where these are named as forming part of the above compositions for mixing
with sulphur or compound sulphur, though I prefer them especially for

page_text: chemical purposes, but I use any other sufficientlyinfusible and unchangeable
material that may be convenient in each particular case, such as granite
porphyry or other stones. Little care is needed in the selection of the stones
when employed in forming concrete and for hydraulic works.
And having now described the nature of my said Invention, and-in what
manner the same is to be performed, I declare that I claim,-
First, the formation of porous material from a composition of sulphur, or
the compound sulphur described herein, with grains of other suitable matter,
such as is herein described.
Second, the casting of such porous materials "with a tail," the cooling of
the same in moulds, and the employment of perforated moulds, as described.
Third, the formation of articles, such as vessels, pipes, tiles, blocks, slabs,
and ornaments, by casting or pressing into moulds a composition of sulphur
with grains of other matter, porous or not.
Fourth, the casting the said non-porous composition "with a head," as
described.
Fifth, the improvement of such composition by the intermixture of all
sized grains of material, as described.
Sixth, the employment of the compound sulphur herein described, in-
stead of plain sulphur, for combining with grains of other material to form
a composition.
Seventh, the employment of the said compound sulphur alone, to form
non-porous materials or articles; and
Eight, the employment of any and all of these improved compositions
of sulphur as a cement, as, for example, for hydraulic works and other
building purposes, for fastening one article into another, as of wood, metal,
or stone, as iron rails into stone blocks, and for coating or lining other articles
or materials therewith.
In witness whereof, I, the said William Petrie, have hereunto set my
hand and seal, this Twelfth day of January, One thousand eight
hundred and fifty-seven.
WILLIAM PETRIE. (L.S.)