THE PRODUCTION OF A NEW OR IMPROVED HYDRAULIC CEMENT OR ARTIFICIAL STONE
Year: 1869

page_text: LETTERS PATENT to Charles Denton Abel, of No. 20, Southampton
Buildings, Chancery Lane, in the County of Middlesex, Patent Agent,
for the Invention of "THE PRODUCTION OF A NEW OR IMPROVED HYDRAULIC
CEMENT OR ARTIFICIAL STONE."-A communication from abroad by
Jules Antoine Dubus, of No. 17, Rue Aubert, St. Denis, near Paris,
in the Empire of France, Civil Engineer.
Sealed the 27th July 1869, and dated the 3rd February 1869.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd February 1869.
I, CHARLES DENTON ABEL, of No. 20, Southampton Buildings;*
Chancery Lane, in the County of Middlesex, Patent Agent, do hereby
declare the nature of the said Invention for "THE PRODUCTION OF A NEW
OR IMPROVED HYDRAULIC CEMENT OR ARTIFICIAL STONE," to be as follows:-
This Invention consists in the production of a hydraulic cement or
artificial stone of a white or tinted colour which resists perfectly the
action of water and decay from other exposure, and is suitable for

page_text: moulding into ornamental and other objects employed for architectural,
sculptural, and other purposes. It rivals natural stone and marble in its
appearance, and is of equal strength with these.
The principal components of this hydraulic cement are lime, silica,
and alumina, the two latter being by preference extracted from refractory 5
clays.
In order to bring about the formation of the double silicate of alumina
and lime, sulphuric and boracic acid are added in small quantities to
the compound.
According to the use to which this artificial stone or hydraulic cement 1
is to be put, and according to the rapidity with which it is required to set
or harden, the proportions of the composing elements are varied between
the following limits :-
Calcium
Silicon
49-939 to 36-703 per cent. by weight.
7.819 to 12-339
5.959 to 9.406
1-119 to 2-130
0.033 to 0.125
do.
"
"
"
39
"3
Aluminium
-
Sulphur
Boron
Oxygen
35 131 to 39.297
""
"
"
"
1
The cements formed between these limits (which cannot be passed
without more or less deterioration of quality) vary in the rapidity with
which they set, but are of equal quality, and attain in course of time 3
about the same degree of hardness.
This cement is subjected to a double roasting or burning process in the
following manner:-The clay in a dry state and the quicklime are first
broken up into small pieces, and are then mixed in the requisite pro-;
portions, to which mixture is added the sulphate of lime and the boracic 3

page_text: acid. This compound, thoroughly incorporated, is then ground to powder
in a suitable mill, giving a dry compound in which the various materials
composing the cement are thoroughly mixed. This powder is then
moistened and worked up in an incorporating mill, from which it passes
in the form of cakes or bricks sufficiently firm for being removed and
piled up under sheds in order to attain the requisite state of dryness.
They are then baked at a white-red heat, after which they are reduced to
an impalpable powder, in which state the cement is ready for use.
The cement cakes may also be prepared in the following manner :-
The quicklime is slaked in water saturated with clay in the requisite
proportions, to which the proper quantities of sulphate of lime and boracio
acid are then mixed, and the whole is then worked up to a perfectly
homogeneous compound. This is then spread out on surfaces where, in
drying, it cracks and separates into more or less regular prisms, which
are readily formed into bricks, which are then dried and baked as
before described. The sulphate of lime and boracic acid may be intro-
duced after such baking instead of before, and either before or after the
bricks are reduced to powder, the result being in either case about the
same. This cement, ground together in suitable proportions with pieces
of marble reduced to an impalpable powder, or with fine granitic sands of
the desired colour, and moistened with the quantity of water strictly
necessary for producing the chemical combinations, gives a pulverous
paste, which may be moulded as well into the most massive forms as into
the most elaborated ornaments. The moulding may be effected by
pressure or otherwise in moulds of any desired form or material. As soon
as the process of moulding is completed the moulds are opened and the
formed object is removed; it may, after being allowed to set for a few
days, be employed for whatever purpose it is intended. The introduction
of the above-mentioned colouring materials does not in any way injure the
quality of the product. These artificial stones can be polished to the
same degree as marble and natural stone, but for this purpose it is
necessary that the sand or other material should be employed in the form
of an impalpable powder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Denton Abel in the Great Seal Patent
Office on the 3rd August 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
DENTON ABEL, of No. 20, Southampton Buildings, Chancery Lane, in
the County of Middlesex, Patent Agent, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of February, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Charles Denton Abel, Her special
licence that I, the said Charles Denton Abel, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Denton Abel,
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
""THE PRODUCTION OF A NEW OR IMPROVED HYDRAULIC CEMENT OR ARTIFICIAL
STONE," a communication to me from abroad by Jules Antoine Dubus, of
No. 17, Rue Aubert, St. Denis, near Paris, in the Empire of France,
Civil Engineer, upon the condition (amongst others) that I, the said
Charles Denton Abel, 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 Charles Denton Abel, 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 say:
This Invention consists in the production of a hydraulic cement or
artificial stone of a white or tinted colour which resists perfectly the
action of water and decay from other exposure, and is suitable for

page_text: proportions, to which mixture is added the sulphate of lime and the
boracic acid. This compound, thoroughly incorporated, is then ground
to powder in a suitable mill, giving a dry compound in which the various
materials composing the cement are thoroughly mixed. This powder is
then moistened and worked up in an incorporating mill, from which it
passes in the form of cakes or bricks sufficiently firm for being removed
and piled up under sheds, in order to attain the requisite state of
dryness. They are then baked at a white-red heat, after which they are
reduced to an impalpable powder, in which state the cement is ready
for use.
The cement cakes may also be prepared in the following manner: —
The quicklime is slaked in water saturated with clay in the requisite pro-
portions, to which the proper quantities of sulphate of lime and boracio
acid are then mixed, and the whole is then worked up to a perfectly
homogenous compound. This is then spread out on surfaces where, in
drying, it cracks and separates into more or less regular prisms, which
are readily formed into bricks, which are then dried and baked as before
described. The sulphate of lime and boracic acid may be introduced
after such baking instead of before, and either before or after the bricks
are reduced to powder, the result being in either case about the same.
This cement, ground together in suitable proportion with pieces of
marble reduced to an impalpable powder, or with fine granitic sands of
the desired colour, and moistened with the quantity of water strictly
necessary for producing the chemical combinations, gives a pulverous
paste, which may be moulded as well into the most massive forms as into
the most elaborated ornaments. The moulding may be effected by
pressure or otherwise in moulds of any desired form or material. As
soon as the process of moulding is completed the moulds are opened and
the formed object is removed; it may, after being allowed to set for a
.few days, be employed for whatever purpose it is intended. Such
artificial stones possess hydraulic qualities which enable them to harden
perfectly in water and to resist all action of the weather. In this
manner imitation marble or stone may be produced either of a perfectly
white colour or of the most diversified tints by employing powdered
marble or other stone or fine sands having naturally the required tint or
which may be coloured artificially. The introduction of such colouring
materials does not in any way injure the quality of the product. These
artificial stones can be polished to the same degree as marble and natural

page_text: stone, but for this purpose it is necessary that the sand or other material
should be employed in the form of an impalpable powder.
Having thus described the nature of this Invention, and in what
manner the same is to be performed, as communicated to me by my
foreign correspondent, what I claim is, the manufacture and employment
of the before-described white or tinted hydraulic cements composed of
refractory clays and lime, with which boracic and sulphuric acids are
mixed, either in the proportions given or in any other proportions.
In witness whereof, I, the said Charles Denton Abel, have hereunto
set my hand and seal, this Third day August, in the year of
our Lord One thousand eight hundred and sixty-nine.