IMPROVE- MENTS IN HARDENING AND COLORING GYPSEOUS LIMESTONE AND SAND, AND CALCAREOUS STONES
Year: 1863

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "IMPROVE-
MENTS IN HARDENING AND COLORING GYPSEOUS LIMESTONE AND SAND, AND
CALCAREOUS STONES."-A communication from abroad by Pascal Nicolas
Balthazar Fioravanti, of Paris, France.
PROVISIONAL SPECIFICATION left by the said Richard Archibald
Brooman at the Office of the Commissioners of Patents, with his
Petition, on the 14th April 1863.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declaro the nature of the said Invention
for "IMPROVEMENTS IN HARDENING AND COLORING GYPSEOUS LIMESTONE AND SAND,
AND CALCAREOUS STONES," to be as follows:-
This Invention is applicable to the hardening and coloring of gypseous
limestones, and rocks, and of sand and calcareous stones.
1st. Hardening and coloring of gypseous limestone.-Preparation: I take
gypseous limestone of any kind, that is to say, laminous, granular, molecular,
marly, sandy, or silicious. I first reduce by suitable tools the pieces to be
treated to artistic dimensions, such as balustrades, ornaments, friezes, columns,
mantle-pieces, decorations for walls, and other architectural and fancy objects;
I then dry them, say in an oven or stove, in order to remove a part of the

page_text: water of crystallization by exposing them to a moderate heat, so regulated
that the air cannot penetrate, for otherwise imperfections would arise. The
temperature to which the stone is submitted in the stove or oven should be
regulated, say from 120° to 250° Fahrenheit according to the size of the
blocks; in treating large pieces, such as columns and tombstones, the heat
should be raised gradually to a much higher degree, and then gradually
lowered. When the stone is removed from the oven or stove it is allowed to
cool, care being taken not to expose to draught, which is injurious to the
manufacture. After removal from the stove and after the stone has cooled
down to a temperature of about 60° to 65°, I place it in a bath containing a
mineral solution, so that it may imbibe 4, 5, 6, or 7 parts of the solution.
The solution should be at a temperature of about from 68° to 86°, and should
be clear and limpid. It may be composed of lime water or sulphate of iron or
cyanides, or alumina, or potass, or soda, or vegetable substances perfectly
combined with minerals or substances obtained from alkaline matters.
Hardening. To harden articles for commercial uses I proceed as follows:-
When the stone has been 3 or 4 minutes in the bath I take it out and expose
it to a temperature of from about 105° to 120°. I then return it to the bath
and allow it to remain therein 6 or 7 minutes. Great care should be taken
in immersing it in the bath, otherwise blisters or other imperfections might
ensue. After sufficient immersion I remove the stone from the bath and
expose it to the air, and the hardening and petrification then commence, the
air absorbs the concentrated water and drives off the water of crystallization.
Heat and air produce an agglomeration of the particles which become com-
pacted in the centre like a species of calamite, the particles attracting each
other. In 10 or 12 hours the stone may be again immersed in the bath if
necessary for 3 or 4 minutes. The operations above described occupy about
2 days, and in 4 days the stone should be polished.
Coloring. For the purpose of coloring I have recourse to a chemical
operation, by means of which I obtain a transformation of colors by making
one solution to chemically succeed another. To form a violet I use prussiate
and sulphate of copper; to obtain a blue I take prussiate and sulphate of iron.
By adding colors such as logwood, gall nuts, fernambue, and alumina I
obtain a series of colors of great variety, even black, by adding an acid. The
colors produced by the processes before described resemble natural marble and
stone; or I can obtain by the foregoing processes colors similar to antique
and modern yellow quartz, alabaster, and wood, or white or flesh color, and
generally imitations of all known objects.
2nd. Hardening and coloring of sand and calcareous stones.-By treating

page_text: sand and calcareous stones by the processes herein-before described, but with
a smaller degree of heat, I obtain a crust capable of receiving a polish which
will enable it to resist the action of air and water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
1
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 14th October 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD'
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of April, in the year of our Lord'
One thousand eight hundred and sixty-three, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Richard Archibald Brooman, Her special licence that I, the said
Richard Archibald Brooman, my executors, administrators, and assigns, or
such others as I, the said Richard Archibald Brooman, 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 HARDENING AND COLORING GYPSEOUS
LIMESTONE AND SAND, AND CALCAREOUS STONES," (communicated to me from
abroad by Pascal Nicolas Balthazar Fioravanti, of Paris, France,) upon the
condition (amongst others) that I, the said Richard Archibald Brooman, 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 per-
formed, 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 Richard Archibald Brooman, 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:―
This Invention is applicable to the hardening and coloring of gypseous
limestones and rocks, and of sand and calcareous stones.
First. Hardening and coloring of gypseous limestones.-Preparation, I take

page_text: gypseous limestone of any kind, that is to say, laminous, granular, molecular,
marly, sandy, or silicious. I first reduce by suitable tools the pieces to
be treated to artistic dimensions, such as balustrades, ornaments, friezes,
columns, mantel pieces, decorations for walls, and other architectural
and fancy objects. I then dry them, say in an oven or stove, in order to
remove a part of the water of crystallization by exposing them to a moderate
heat so regulated that the air cannot penetrate, for otherwise imperfections
would arise. The temperature to which the stone is submitted in the stove or
oven should be regulated, say, from 120° to 250° Fahrenheit, according to the
size of the blocks; in treating large pieces, such as columns and tombstones,
the heat should be raised gradually to a much higher degree and then
gradually lowered. When the stone is removed from the oven or stove it is
allowed to cool, care being taken not to expose it to draught, which is
injurous to the manufacture. After removal from the stove, and after the
stone has cooled down to a temperature of about 60° to 65°, I place it in a
bath containing a mineral solution, so that it may imbibe 4, 5, 6, or 7 parts
of the solution; the solution should be at a temperature of about from
68° to 86°, and should be clear and limpid. It may be composed of limo
water, sulphate of iron, cyanides, alumina, potass, soda or vegetablo sub-
stances perfectly combined with minerals or substances obtained from alkaline
matters.
Hardening. To harden articles for commercial uses I proceed as follows:-
When the stone has been 3 or 4 minutes in the bath I take it out and expose
it to a temperature of from about 105° to 120°; I then return it to the bath
and allow it to remain therein 6 or 7 minutes. Great care should be taken in
immersing it in the bath, otherwise blisters or other imperfections might
ensue. After sufficient immersion I remove the stone from the bath and
expose it to the air, and the hardening and petrifaction then commence; the
air absorbs the concentrated water and drives off the water of crystallization.
Heat and air produce an agglomeration of the particles which become com-
pacted in the centro like a species of calamite, the particles attracting each
other. In 10 or 12 hours the stone may be again immersed in the bath if
necessary for 3 or 4 minutes. The operations abovo described occupy about
2 days, and in 4 days the stone should be polished.
Coloring. For the purpose of coloring I have recourse to a chemical
operation, by means of which I obtain a transformation of colors by making
one solution to chemically succeed another. To form a violet I use prussiate
and sulphate of copper; to obtain a blue I take prussiate and sulphate of irou.
By adding colors, such as logwood, gall nuts, fernambuc, and alumina, I

page_text: obtain a series of colors of great variety, even black, by adding an acid. The
colors produced by the processes before described resemble natural marble and
stone; or I can obtain by the foregoing processes colors similar to antique and
modern yellow quartz, alabaster, and wood, or white or flesh color, and generally
imitations of all known objects.
Second. Hardening and coloring of sand and calcareous stones.-By treating
sand and calcareous stones by the processes herein-before described, but with
a smaller degree of heat, I obtain a crust capable of receiving a polish, which
will enable it to resist the action of air and water.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim, hardening and
coloring gypseous limestone and sand and calcareous stones, substantially by
the means and in manner herein-before described.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Fourteenth day of October One
thousand eight hundred and sixty-three.
R. A. BROOMAN. (L.B.)