IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL MARBLE
Year: 1874

page_text: LETTERS PATENT to William Charles Arthur Roettger, of 175, Rue
Gaucheret, Brussels, in the Kingdom of Belgium, for the In-
vention. of "IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL
MARBLE
"
PROVISIONAL SPECIFICATION left by the said William Charles
Arthur Roettger at the Office of the Commissioners of Patents;
with his Petition, on the 2nd September 1874.
1, WILLIAM CHARLES ARTHUR RŒTTGER, of 175, Rue Gaucheret,
Brussels, in the Kingdom of Belgium, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL
MARBLE," to be as follows:-
1
The main compound of this marble is a fine white cement prepared
from Iceland spar or cale spar or their equivalents by burning in kilns.
When cooled down the stones are placed into soak in a bath containing
silica soluble in water. When the stones thus exposed in the bath have

page_text: For white marble I mix 3% of oxide of zinc to 97 of cement.
°
For black kinds I employ the peroxide of manganese, and for
colored kinds, diversc mineral oxides, avoiding entirely organic or
vegetable colors.
Having most carefully ground and mixed my colors in accordance
with the shade of marble required to be made, I proceed to mix the 1
cement with water to the consistency of a thick cream, to which I add
the colors in a moist state, and if necessary pass the mixture through a
fine hair sieve. With these colored pastes I lay on a flat engraved or
embossed surface the various veins, their tints, and colors, and all the
other shades of the marble which I wish to represent on the surface of
the marble which I am making, and proceed otherwise in the same
manner as if I were to take a cast in plaster of Paris.
In an ordinary slab I lay the thickness of the colored paste to about
an eighth of an inch, and having carefully passed the same with a
trowel to insure that the whole surface to be covered with cement has 2
been covered, I spread on this first or colored layer a thin cloth on
which I place, under ordinary circumstances, a dry cement of a coarser
kind, common plaster of Paris, sifted ashes, or even sand, in order to
withdraw the superfluous water in the first layer of colored cement.
After this I remove the cloth and pass the trowel once more in order
to fill up any crevasses that may have occurred during the last-mentioned
operation.
If the drying has been effected with coarse cement of the same com-
position as the fine cement, I mix it with a little more water as well as
with the remaining coloring matter to a much stiffer consistence than's

page_text: the first mixed cement, and lay on a layer about the same thickness as
the first.
If the object made offers a rather large surface in proportion to its
intended thickness, I introduce on this second layer a piece of coarse
canvas, which has been previously saturated in a solution of silicate of
potash or soda, or sulphate of copper, in order to preserve it from rot
and prevent it shrinking when in the cement. On this I now lay the
last part of the coarse cement, as stated above..
When the marble has to represent sculpture, and a chisel has to be
used afterwards in order to correct the object produced, I lay the
colored surface on much thicker by degrees; having first made the same
thickness, as before stated, I dry with the same fine cement, which I
afterwards employ mixed with water and colors, and which will serve as
a second colored layer. I continue this process until I have the thick-
ness wanted.
In order to drive out the air that is to be met with in bubbles in the
wet cement after it was laid on, I employ a piece of wood in the shape
of a large brush, where in the place of bristles there are pieces of wood
or brass wire of the thickness of a good sized pin inserted; with this
I press the back of the piece of work done; afterwards I pass a
trowel.
My Invention further relates to the application of the above cements
in combination with Portland and other cements in the manufacture of
tiles for pavement. For this proceeding. I mix the colors and the fine
cement in a dry state, and then only moisten the cement; afterwards I:
place this colored cement into a mould and then back it up with:
Portland or other cements and sand or gravel. The whole is now pressed:
by a strong press, taken out, and allowed to dry.
When I wish to produce inlaid work I make the different shapes
and colors destined for incrustation first in special moulds out of the
fine colored cement only; I afterwards place the objects so made into'
large moulds; fill in the body as before, and then take out of the mould'
and allow to dry.
The surface of the objects made is polished with water and stones.
(pumice stone and snake stone), and holes that may appear on the
surface are filled in with the same cement and color of the object.
1
}

page_text: When thoroughly dry I rub the surface with oil once or twice. If after
this there should appear a kind of rust still on the surface, I wash it
with diluted hydrochloric acid. When dry again I polish the surface.
with a mixture of silicate of soda or silicate of potash water and olive
oil, and place on the surface whilst rubbing, a little fine ashes or fine 5
emery powder.
The result is a brilliant and lasting polish.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Charles Arthur Roettger in the Great
Seal Patent Office on the 1st March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CHARLES ARTHUR RŒTTGER, of 175, Ruc Gaucheret, Brussels, in the
Kingdom of Belgium, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of September, in the
year of our Lord One thousand eight hundred and seventy-four, in
the thirty-eighth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said William Charles Arthur
Roettger, Her special license that I, the said William Charles Arthur
Roettger, my executors, administrators, and assigns, or such others as
I, the said William Charles Arthur Roettger, my executors, admini-
strators, 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 MARBLE," upon the condition (amongst
others) that I, the said William Charles Arthur Roettger, my executors
or administrators, 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 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.
.

page_text: NOW KNOW YE, that I, the said William Charles Arthur Roettger,
do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is
to say :-
The main compound of this marble is a fine white cement prepared
from Iceland spar or cale spar or their equivalents by burning them in
kilns. Blocks of the materials employed thus burned are when perfectly
cooled down placed in a bath containing a solution of certain salts,
which being the result of decomposition of aluminium, borax, copper,
iron, potassium, sodium, &c., are soluble in water. These salts aro
either silicates, sulphates, or acids, and are added to the water for the
bath at the rate of one hundred grammes (=3 of an ounce) to one litre
(=1 quart) of soft water. When the stones thus exposed in the bath
have absorbed a sufficient quantity of silica, they are withdrawn, dried in
the air, burned again, and afterwards reduced in the ordinary way to the
fineness required.
In the burning process great care is to be taken not to expose the
blocks saturated as above described to too sudden nor to too great a
heat; as the quality of the cement will greatly depend on the reburning
process, much attention has to be paid to what I have just stated. The
heat of the blocks should not excced an ordinary red heat.
I also use alabaster or marble cements or other substances containing
sulphate of lime in admixture with alum or sulphates of metals, but a
cement containing a certain per-centage of silica, alumina, copper, borax,
or iron is preferable.
Where alum or sulphates form ingredients of the cement I introduce
when mixing them for use in order to harden them binoxide of
hydrogen HO,, or oxygenated water sufficient to form the cement into
a paste fit to be worked with.
For white marble I mix 3% of oxide of zinc to 97 of cement.
For black kinds I employ the peroxide of manganese, and for coloured
kinds diverse mineral oxides, avoiding entirely organic or vegetable
colours.
Having most carefully ground and mixed my colours in accordance
with the shade of marble required to be made, I procced to mix the

page_text: cement with water to the consistency of a thick cream to which I add
the colours in a moist state, and if necessary pass the mixture through
a fine hair sieve. With these coloured pastes I lay on a flat engraved or
embossed surface the various veins, their tints and colours, and all the
other shades of the marble which I wish to represent on the surface of
the marble which I am making, and proceed otherwise in the same
manner as if I were to take a cast in plaster of Paris:
In an ordinary slab I lay the thickness of the coloured paste to about
an eighth of an inch, and having carefully passed the same with a trowel
to ensure that the whole surface to be covered with cement has been
covered, I spread on this first or coloured layer a thin cloth on which I
place under ordinary circumstances a dry cement of a coarser kind,
common plaster of Paris, sifted ashes, or even sand, in order to withdraw
the superfluous water in the first layer of coloured cement. After this
I remove the cloth and pass the trowel once more in order to fill up
any crevices that may have occurred during the last mentioned
operation.
If the drying has been effected with coarse cement of the same
composition as the fine cement I mix it with a little more water as well
as with the remaining colouring matter to a much stiffer consistence than
the first mixed cement, and lay on a layer about the same thickness as
the first.
If the object made offers a rather large surface in proportion to
its intended thickness, I introduce on this second layer a piece of
coarse canvas which has been previously saturated in a solution of:
silicate of potash or soda, or sulphato of copper, in order to preserve it
from rot and prevent it shrinking when in the cement. On this I now
lay the last part of the coarse cement as stated above.
When the marble has to represent sculpture, and a chisel has to be.
used afterwards in order to correct the object produced, I lay the coloured
surface on much thicker by degrees, having first made the same thickness.
as before stated. I dry with the same fine cement, which I afterwards
employ mixed with water and colours, and which will serve as a second
coloured layer. I continue this process until I have the thickness
wanted.
In order to drive out the air that is to be met with in bubbles in the
wet cement after it was laid on, I employ a piece of wood in the shape
of a large brush, where in the place of bristles there are pieces of wood.

page_text: or brass wire of the thickness of a good-sized pin inserted; with this I
press the back of the piece of work done. Afterwards I pass a trowel.
My Invention further relates to the application of the above cements
in combination with Portland and other cements in the manufacture of
tiles for pavement. In this proceeding I mix the colours and the fine
cement in a dry state, and then only moisten the cement without making
it into a paste. Afterwards I place this coloured cement so. moistened.
into a press containing a mould or die, which will give the shape or form
required. This press resembles much an ordinary brick press, having a
zinc or iron plate in the bottom of the mould, on which the newly made
cement tile is removed from it. Having placed the fine cement into
the mould in the proportion of about 10, I back it up with 10 of a
concrete mixture, made of silicate, Portland, or any other hydraulic
cements, one part; sand or gravel, five parts; hydraulic lime, one part.
These proportions may be varied according to the binding power of the
cement employed for backing. The whole is now condensed by a strong
pressure, taken out, and allowed to dry.
Where I wish to produce inlaid work I make the different shapes and
colours destined for incrustation first in special moulds out of the fine
coloured cement only. I afterwards place the object so made into larger
moulds, fill in the body as before with fine cement or cement and colour
combined, and then take out of the mould and allow to dry. In order to
amalgamate any particle of cement which may not have been saturated
by the moistening process, or to remove impurities, I dip the tiles so
manufactured, after they have set, into ordinary water, and then let
them completely dry.
The surface of the objects made is polished with water and stones
(pumice stone and snake stone), and holes that may appear on the surface
are filled in with the same mixture of cement and colour as the object.
When thoroughly dry I rub the surface with oil once or twice. If after
this there should appear a kind of rust or film still on the surface, I wash
it with diluted hydrochloric acid. When dry again I polish the surfaco
with a mixture of silicate of soda or silicate of potash, about 7 (seven)
per cent.; olive oil, 3 (three) per cent.; and 70 (seventy) per cent. of
soft water. This mixture I put on a soft rag with a little tin ashes or
emery powder, and then rub the surface with it. The result is a brilliant
and lasting polish.

page_text: Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim,—
1
First. The mode, substantially as herein described, of making a
certain cement or cements for the manufacture of artificial marble or
stone.
Second. The method of hardening artificial marble or stone manu-
factured by my process, as herein described.
Third. The use of mineral salts in the shrinking process of the canvas
to be employed for backing of artificial marble slabs.
Fourth. The use of a kind of brush-shaped wood having pins or pegs 1
in the place of bristles for the expulsion of air from the cement after
being laid on, as heretofore, described.
Fifth. The method of using the cements above described in the manu-
facture of paving tiles or blocks alone, or iu combination with others, in
operating substantially as herein described.
Sixth. The mode of polishing such marble or stone as herein described,
or any other object requiring a lasting polish, with the ingredients, as
heretofore stated.
]
In witness whereof, I, the said William Charles Arthur Roettger,
have hereunto set my hand and seal, this Twelfth day of February, 2
in the year of our Lord One thousand eight hundred and seventy-
fivc.