IMPROVE- MENTS IN THE MANUFACTURE OF ARTIFICIAL STONE
Year: 1856

page_text: LETTERS PATENT to Lemuel D. Owen, of Southampton Street, London,
in the County of Middlesex, Engineer, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF ARTIFICIAL STONE."-A communication.
ed the 25th November 1856, and dated the 28th May 1856.
PROVISIONAL SPECIFICATION left by the said Lemuel D. Owen at the
Office of the Commissioners of Patents, with his Petition, on the
28th May 1856..
I, LEMUEL D. OWEN, of Southampton Street, London, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Invention
for IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL STONE," (a communica
tion from a foreigner residing abroad,) to be as follows:-
This Invention consists in forming blocks, for building purposes, from the
well-known ingredients silicious sand and lime, or, where sand is not obtain-
able, from lime, and pulverised scoria from furnaces, or pulverised brick, or
other pulverulent substances containing silicious matter. The proportions of
lime and sand, or other pulverulent substance containing silicious matter, vary
according to the quality of the lime, and of the sand or other substance which
has to be mixed with it; but when sand is used, the proportion is about one
part of lime to twelve parts of sand; the lime, which must be newly slacked,
is mixed with the sand, which latter requires a certain degree of moisture. A
mould is then filled with this composition and placed into a press, similar to
those used for the manufacture of ordinary bricks from pulverulent clay, and
there submitted to a pressure of about three tons to the square inch; if the
size of the block is that of a common brick, thicker blocks requiring more, and
thinner blocks less pressure. After baving undergone this process, the blocks

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are carefully removed and placed upon a flat surface, where they are allowed
to dry or ripen. Where practicable, the block should be perforated in one or
more places, so as to allow of free access of the atmospheric air into the
interior of the block. The carbonic acid of the atmospheric air combines with
the hydrate of lime and forms carbonate of-lime, a change which, if the blocks
are not perforated, might require a considerable time. The blocks manu-
factured in the manner described become indurated in the course of a few
months to such a degree that they cannot be easily distinguished from natural
sandstone. The composition used may be mixed with oxides of metal, or
other suitable coloring matter, in order to give the blocks any desired color...
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Lemuel. D. Owen in the Great Seal Patent Office on the
28th November 1856:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LEMUEL
D. OWEN, of Southampton Street, London, in the County of Middlesex,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of May, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Lemuel D. Owen, Her special licence. that I, the said Lemuel D. Owen, my
executors, administrators, and assigns, or such others as I, the said Lemuel
D. Owen, my executors, administrators, and assigns, should at any time agree
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, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF ARTIFICIAL STONE," (a communication,)" upon the condition
(amongst others) that I, the said Lemuel D. Owen, my executors or adminis-
trators, by an instrument 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
samme 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 Lemuel D. "Owen, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the following
statement (that is to say) in
The said Invention consists in forming blocks of artificial. stone, for building
purposes, as a substitute for bricks and stones. The bases of this improved
building block ȧare lime and silicious sand, articles which are old and well-
known materials for building purposes, and which have been used in a great
variety of relative proportions, either as mortar to cement stones or bricks
together, as concrete. to make foundations, or for other purposes. But this
Invention is clearly distinguishable from all these; for although it is composed.
of such old and well-known material, yet these materials are so combined. as
to give to the block new properties and advantages essentially different from
those possessed by any other known artificial building material.
.The manner in which these new building blocks are formed, is as follows:-
A quantity of coarse silicious sand, as free as possible from admixture with clay
or other earth is provided, together with a quantity of freshly slacked lime in
powder. As much sand and lime as can be moulded into blocks during an
hour are then to be thoroughly mixed together, in the proportion of about one
part of lime to from six to twelve parts of sand, according to the nature of the
sand or the quality of the lime, the lime being the dry powder hydrate pro-
duced when lumps of calcined limestone are freshly slacked, and the. sand:
having that degree of moisture it ordinarily has when dug out of. the earth.
If preferred; the calcined limestone may be ground and mixed with the sand
previous to being slacked, and then as much water added: as is necessary for
the process of slacking; this composition is then placed into the mould, of the
required shape of a moulding press, similar to those used for making bricks
from pulverulent clay, and is there submitted to great pressure, which should
be proportioned to the thickness of the block required. A suitable pressure
for a block of 3 inches thick would be about 3 tons to the square inch; blocks
may be formed under less pressure, but it is evident that the compactness of
the block increases with the pressure to a certain extent. After the block has
been submitted to this pressure, it is carefully removed from the mould and
laid upon a flat surface, with free access of air, where it should remain until
sufficiently hardened or ripened, when it will be ready for usc. For the
purpose of facilitating the ripening of the block, it should, if larger than a
common brick, be perforated with one or more holes; these will admit the
atmospheric air into the interior of the block, whereby the hydrate of lime will
be converted into carbonate, a change which, if the blocks were large and solid,
would require a considerable time.
J
8
The particles of sand in the composition are, by the heavy pressure to which

page_text: it is subjected, forced into such close proximity, that it requires but very little
cement to fill the interstices and agglomorate them together into a block-of
compact sandstone. The blocks thus, made become indurated after a few
months to such a degree that they are not readily distinguishable from natural
sandstone. In the preparation of this material care must be. taken, not to
employ wet. sand, because if there is an excess of moisture, to such a degree
as to exude water whilst the block is pressed, it would be impossible to give to
the mass the requisite solidity, as the cohesion of the water to the sand and
lime is so strong, and its incompressibility so great, that it could not be expressed
in the very brief space of time during, which the block is exposed to pressure.
This excess of water would afterwards evaporate, leaving the block com-
paratively porous, light, and, friable; it also would be much longer in
hardening crack; in drying, and not maintain its shape. When sand is not readily
obtainable, coarsely pulverized scoria from furnaces, bricks, or other pulverulent
silicious matter may be employed in place of the sand; the lime and sand may
be mixed with oxides of metal, or other coloring matter, to give the blocks any
desired color. These blocks dry without shrinking or warping, and hence possess
great advantages over bricks which always shrink much and very unequally,
and also warp in burning. Blocks may be made in any desirable form or
shape, plain or ornamental, perforated or solid. For blocks intended for
building in water, waterlime is used. These blocks are made in a similar
manner to those above described, but when removed from the press and suf-
ficiently set, it is well to submerge them in water for a time, by which means
they will rapidly grow hard and fit for use.
Having now described the nature of the Invention which has been commu-
nicated to me, I would have it understood that what I claim, as the Invention
secured to me by the herein-before in part recited Letters Patent, is the
manufacture of blocks of artificial stone from sand or other pulverulent silicious
matter in combination with lime, and formed in moulds under great pressure,
as herein-before described.
In witness whereof, I, the said Lemuel D. Owen, have hereunto set my
hand and seal, this Twenty-eighth day of November, in the year of our
Lord One thousand eight hundred and fifty-six.
LEMUEL D. OWEN. (L.S.)