AN IMPROVED METHOD OF HARDENING AND COLORING ALABASTER AND OTHER GYPSUMS AND CALCARIOUS STONES AND EARTHS
Year: 1856

page_text: LETTERS PATENT to Louis Jacquemier, of Rome, now residing at
Charlotte Street, Fitzroy Square, in the County of Middlesex, Gentle-
man, for the Invention of "AN IMPROVED METHOD OF HARDENING AND
COLORING ALABASTER AND OTHER GYPSUMS AND CALCARIOUS STONES AND
EARTHS." A communication from the Marquis Campana.
PROVISIONAL SPECIFICATION left by the said Louis Jacquemier at the
Office of the Commissioners of Patents, with his Petition, on the
18th September 1856.
I, LOUIS JACQUEMIER, of Rome, now residing at Charlotte Street, Fitzroy
Square, in the County of Middlesex, Gentleman, do hereby declare the nature
of the said Invention for "AN IMPROVED METHOD OF HARDENING AND COLORING
ALABASTER AND OTHER GYPSUMS AND CALCARIOUS STONES AND EARTHS," (com-
municated to me by the Marquis Campana, a foreigner residing abroad,) to be
as follows:-
This Invention consists in exposing alabaster and every other kind of
gypsum to a heat of about 212° Fahrenheit, in order to expel and drive off
therefrom the watery particles contained in it. The time during which the
gypsum must be so exposed will vary with the nature of the material, but

page_text: experience will soon dictate the precise time to the operator. When suffi-
ciently dried, or when the aqueous particles have been driven off, the gypsum
is plunged several times in succession in clear water at the temperature of the
atmosphere, or in any other suitable hardening liquid, or substance, or com
position reduced to a liquid state, and when the operator finds by experience
that the plunging has been continued for a sufficient length of time, the
gypsum is withdrawn and exposed to the atmosphere to complete the hardening
process, which requires from five to thirty days, more or less, after which the
gypsum is in a fit state to be polished and treated in all respects in a manner
similar to marble, which it will be found very much to resemble; in fact;
by operating upon gypsum in the manner described an artificial marble is
produced.
In order to color the gypsum, any suitable colouring material may be mixed
with the water in which it is plunged after the drying process, but the
colors most preferred are those produced from minerals reduced to a state of
solution.
The method of hardening and coloring herein-before described with re-
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Louis Jacquemier in the Great Seal Patent Office on the
16th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LOUIS
JACQUEMIER, of Rome, now residing at Charlotte Street, Fitzroy Square, in
the County of Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of September, 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 Louis Jacquemier, Her special licence that I, the said Louis Jacquemier,
my executors, administrators, and assigns, or such others as I, the said
Louis Jacquemier, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "AN IMPROVED
METHOD OF HARDENING AND COLORING ALABASTER AND OTHER GYPSUMS AND CAL-

page_text: CARIOUS STONES AND EARTHS," (communicated to me by the Marquis Campana,
a foreigner residing abroad,") upon the condition (amongst others) that I,
the said Louis Jacquemier, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should par-
ticularly 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 Louis Jacquemier, 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:―
Alabaster, gypsum, gypsous rocks, and calcarious stones and earths are
naturally always more or less soft, brittle, tenacious, and compact, and so friable
and easily injured or marked that, notwithstanding their apparent beauty, they
cannot be used in the arts without at least being decomposed by the action of
fire, and recomposed and prepared by the various purposes to which they are
to be applied. The alabasters of volterra and other gypsums are of little value
on account of their friability and their facility in absorbing dust or other subtle
matters, which makes them become dirty and of little use.
Now, the object of this Invention is to change the character of alabaster and
of gypsous rocks, and to render them like marble. Gypsous rocks, prepared in
the manner hereafter described, are no longer susceptible of being easily broken
or injured by hard bodies; they are not liable to absorb dust or other matter
which would discolour them; on the contrary, various tints can now be given
to them, and they will take a polish like marble, resemble marble, and may be
used for all purposes of decorations and objects of fancy.
The Invention consists in exposing alabaster and every other kind of
gypsum and calcarious stones and earths to a heat of about 212° Fahrenheit,
in order to expel and drive off therefrom the watery particles contained in it.
The time during which the gypsum must be so exposed will vary with the
nature of the material, but experience will soon dictate the precise time to the
operator. When sufficiently dried, or when the aqueous particles have been
driven off, the gypsum is plunged several times in succession in clear water at
the temperature of the atmosphere, or in any other suitable hardening liquid,
or substance or composition reduced to a liquid state; and when the operator
finds by experience that the plunging has been continued for a sufficient length
of time, the gypsum is withdrawn and exposed to the atmosphere to complete
the hardening process, which requires from five to thirty days, more or less,

page_text: after which the gypsum is in a fit state to be polished and treated in all
respects in a manner similar to marble, which it will be found very much to
resemble; in fact, by operating upon gypsum in the manner described, an
artificial marble is produced.
In order to color the gypsum, any suitable coloring material may be
mixed with the water in which it is plunged after the drying process, but the
colors most preferred are those produced from minerals reduced to a state of
solution, some of which, as, for example, sulphates of iron and copper, not only
impart color to the material, but also harden it additionally.
The method of hardening and coloring herein-before described with re-
ference to gypsum may also be applied to all calcarious stones and earths.
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 the hardening
and coloring of alabaster and other gypsums and calcarious stones and earths,
in the manner herein-before described.
In witness whereof, I, the said Louis Jacquemier, have hereunto set my
hand and seal, this Third day of March, One thousand eight hundred
and fifty-seven.
Witness,
CH. ARMENGAUD, Civil Engineer,
23, Boulevard de Strasbourg,
à Paris.
L. JACQUEMIER. (L.S.)