IMPROVEMENTS IN THE MEANS OF PRE- SERVING STONE, BRICK, SLATE, WOOD, CEMENT, STUCCO, PLASTER, WHITEWASH, AND COLOURWASH FROM THE INJURIOUS ACTION OF ATMOSPHERIC AND OTHER INFLUENCES; ALSO IN THE APPLICATION OF COLOURS TO THE SURFACES OF STONE, BRICK, SLATE, WOOD, CEMENT, STUCCO, MORTAR, CLAY, PLASTER OF PARIS, PLASTER, WHITEWASH AND COLOURWASH, AND IN THE RETENTION OF SUCH COLOURS THEREON
Year: 1862

page_text: ETTERS PATENT to Arthur Herbert Church, of 170, Great Portland
Street, in the Parish of Saint Marylebone, in the County of Middlesex,
Chemist, for the Invention of "IMPROVEMENTS IN THE MEANS OF PRE-
SERVING STONE, BRICK, SLATE, WOOD, CEMENT, STUCCO, PLASTER, WHITEWASH,
AND COLOURWASH FROM THE INJURIOUS ACTION OF ATMOSPHERIC AND OTHER
INFLUENCES; ALSO IN THE APPLICATION OF COLOURS TO THE SURFACES OF STONE,
BRICK, SLATE, WOOD, CEMENT, STUCCO, MORTAR, CLAY, PLASTER OF PARIS,
PLASTER, WHITEWASH AND COLOURWASH, AND IN THE RETENTION OF SUCH
COLOURS THEREON."
Sealed the 15th July 1862, and dated the 28th January 1862.
PROVISIONAL SPECIFICATION left by the said Arthur Herbert Church
at the Office of the Commissioners of Patents, with his Petition, on
the 28th January 1862.
I, ARTHUR HERBERT CHURCH, of 170, Great Portland Street, in the
Parish of Saint Marylebone, in the County of Middlesex, Chemist, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE MEANS
OF PRESERVING STONE, BRICK, SLATE, WOOD, CEMENT, STUCCO, PLASTER, WHITE-
WASH AND COLOURWASH FROM THE INJURIOUS ACTION OF ATMOSPHERIC AND OTHER
INFLUENCES; ALSO IN THE APPLICATION OF COLOURS TO THE SURFACES OF STONE,
BRICK, SLATE, WOOD, CEMENT, STUCCO, MORTAR, CLAY, PLASTER OF PARIS, PLASTER,
[Price 8d.]

page_text: WHITEWASH, AND COLOURWASH, AND IN THE RETENTION OF SUCH COLOURS THEREON,"
to be as follows:-
I propose to make use of a solution of caustic baryta or strontia, followed
or preceded by a solution of silicic acid in wateras an application for hardening
or preserving stone, brick, slate, wood, cement, stucco, mortar, clay, plaster of
paris, plaster, whitewash, and colourwash; and for protecting the same from
injurious atmospheric and other influences, I propose to apply to the stone or
other substance to be protected, firstly, a solution of caustic baryta or
strontia, but preferably baryta; and, secondly, a solution of silicic acid in
water once or twice, to be followed in certain cases by a second application of
the solution of caustic baryta or strontia. In particular instances where, from
the structure or composition of the stone or other material it is preferable, I
propose to reverse the order of the application of the solution of baryta or
strontia and of the solution of silicic acid, applying, firstly, the solution of
silicic acid, and, secondly, the solution of baryta or strontia. The effect of
the consecutive application of the above-named solutions tothestoneandother
materials herein-before mentioned is the hardening and preserving of the
materials so treated and the counteracting of the injurious effects upon them
of atmospheric and other influences by means of the insoluble silicate of lime,
baryta, or strontia formed within and upon such materials by such applica-
tion, I furthermore propose to use the same process for fixing and preserving
colours onsurfaces of stone and of theother herein-beforementionedmaterials.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Arthur Herbert Church in the Great Seal Patent Office on
the 25th July 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
HERBERT CHURCH, of 170, Great Portland Street, in the Parish of St.
Marylebone, in the County of Middlesex, Chemist, send greeting.
WHEREAS Her Most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of January, in the yearof our Lord
One thousand eight hundred and sixty-two, in the 'twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Arthur Herbert Church, Her special licence that I, the said Arthur
Herbert Church, my executors, administrators, and assigns, or such others
as I, the said Arthur Herbert Church, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time

page_text: 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 Inven-
tion for "IMPROVEMENTS IN THE MEANS OF PRESERVING STONE, BRICK, SLATE,
WOOD, CEMENT, STUCCO, PLASTER, WHITEWASH AND COLOURWASH FROM THE
INJURIOUS ACTION OF ATMOSPHERIC AND OTHER INFLUENCES; ALSO IN THE APPLI-
CATION OF COLOURS TO THE SURFACES OF STONE, BRICK, SLATE, WOOD, CEMENT,
STUCCO, MORTAR, CLAY. PLASTER OF PARIS, PLASTER, WHITEWASH AND COLOURWASH,
AND THE RETENTION OF SUCH COLOURS THEREON," upon the condition (amongst
others) that I, the said Arthur Herbert Church, 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 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 Arthur Herbert Church, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement (that is to say) :-
My Invention has for its object improvements in the means of preserving
stone, brick, slate, wood, cement, stucco, plaster, whitewash, and colourwash
from the injurious action of atmospheric and other influences; also in the
application of colours to the surfaces of the aforesaid materials, and to the
surfaces of mortar, clay, and plaster of Paris, and in the retention of such
colors thereon. For the purpose of preserving or hardening stone and the
other herein-before mentioned materials, I impregnate them, firstly, with a
solution of baryta or strontia in water, but preferably with a solution of baryta,
the strength of such solution varying according to the nature of the material
operated upon, the required strength being ascertained by special experiment
in each case. For example, I have found that certain specimens of dolomite.
and compact limestone, upon which I have operated, required the use of weak
solutions of baryta or strontia, while on the other hand, certain specimens of
porous Bath oolite, friable coarse-grained sandstone, and brick required the
use of strong solutions in order to secure a successful result. I impregnate
the stone or other material with the solution of baryta or strontia by any
process usually applicable in such cases, for. intance, by washing them with
such solutions, by immersing them in such solutions, or by causing such
solutions to enter into the pores of the stone or other material by means of

page_text: atmospheric or other pressure. In order to prepare the solution of baryta or
strontia, I take dry caustic baryta or strontia, slake it with water, and add
more water so as to make the hydrate of baryta or strontia thus formed into
a paste of the consistency of cream, and I then boil this paste with such a
proportion of water, preferably rain or distilled water, that the solution of
baryta or strontia thus formed may contain as much hydrate of baryta or
strontia as water at the temperature employed is capable of dissolving, or any
less proportion that may be found effective. I prefer to apply the solution to
the stone or other material at or near the boiling temperature of such soln-
tion, and if there be solid matter in such solution I allow it to subside out
of contact with the atmosphere. In place of dry caustic baryta or strontia
the precipitated, crystallized, or otherwise prepared hydrates of baryta or
strontia may be employed in making the aforesaid solution of baryta or
strontia.
In the second place I impregnate stone and the other herein-before men-
tioned materials with a solution of silica, otherwise called silicic acid, in
water, the strength of such solution varying from one to fifteen per cent. of
dry silica, according to the nature of the material operated upon, the required
strength being ascertained by experiment in each case. For example, I have
found that certain specimens of dolomite and compact limestone, upon which
I have operated, required the use of a weak solution of silica, while on the
other hand certain specimens of porous Bath oolite, friable coarse grained
sandstone and brick required the use of a strong solution in order to secure a
successful result. Such solution of silica in water may be prepared by any of
the known processes for obtaining the same, but preferably by the process
known as dialysis. The following is an example of the way in which I
generally prepare such solution of silica:-I take one volume of a strong
solution of silicate of potash or soda of specific gravity 1.5, or thereabouts,
and having diluted it with two volumes of water I add this diluted solution to
five volumes of water containing such a proportion of sulphuric, hydrochloric,
or other common and suitable acid as shall suffice not only to neutralize the
alkaline reaction of the above described solution of silicate of soda or potash,
but also to render such solution strongly acid, occasionally I employ the liquid
mixture thus prepared at once for the purposes of my present Invention, its
application to stone or other material being preceded or succeeded by the
similar application of a solution of baryta, or strontia, generally, however, I
place the liquid mixture thus prepared upon a dialyser floating on or suspended
or otherwise contained in distilled rain or other water, but preferably in dis-
tilled or rain water. When the whole or greater part of the salts and acid

page_text: have diffused away, I take the. liquid remaining in the dialyser, which liquid
is a solution more or less pure of silica in water, and employ it as herein-
before, described for the purposes of my Invention; I prefer to employ this
solution of silica in water as soon after it has been prepared as possible since
it then penetrates further into the stone or other material to be preserved
than when it has been kept sometime. And I also. prefer to employ as soon
as possible after its preparation the acid mixture resulting from the addition
of silicate of soda or potash to excess of sulphuric, hydrochloric, or other
common aud suitable acid, and which acid mixture may be regarded as an
impure solution of silica in water.
In applying the above-described solutions of baryta or strontia and of
silica to the purposes of my Invention I operate in a manner of which the
following examples may be taken as illustrations:-Supposing that it is
desired to harden limestone, dolomite, sandstone, or other similar materials,
and to preserve them from the injurious action of atmospheric and other
influences, I brush such stone or other material over with a hot solution of
baryta in water containing, say,two per cent. of hydrate of baryta till it ceases
to be absorbed, and a few hours afterwards I brush the surfaces so treated over
with a solution of silica in water containing, say, six per cent. of dry silica.
In certain cases I not only permit the stone or other material to absorb as
much as possible of the above-named solutions, but I repeat the consecutive
application of the two solutions to the surfaces to be operated upon. Generally
I apply the solution of baryta or strontia once, and follow up such application
by two or more applications of the solution of silica.
Again, in other cases, more especially where brick, terra cotta, certain
sandstones, and other materials are to be operated upon, I prefer to apply to
such inaterials, in the first place, a solution of silica containing,say, five or
six per cent. of dry silica till it is no longer absorbed ; and then, in the second
place, after the lapse of a day, a hot solution of baryta or strontia containing,
say, two per cent of hydrate of baryta or strontia. Where practicable I
prefer to impregnate the stone or other material with the above-described
solutions of baryta or strontia and of silica, by removing from the pores of
the stone or other material the air contained therein, and then allowing the
above-named solutions to fill such pores. And, in particular instances, where
owing to the composition or structure of the stone or other material it is
preferable, I prefer to reverse the order of application of the solution of
baryta or strontia and of the solution of silica, whatever may be the strength
of the respective solutions so applied.
The effect of the successive or consecutive application of the solution of

page_text: baryta or strontia and of the solution of silica to stone and the other herein-
before mentioned materials, is the hardening and preserving of the materials
so treated, the counteracting ofthe injurious effects upon them of atmospheric
and other influences, and the rendering them more impervious to water by
means of the insoluble silicate of baryta or strontia formed within and upon
such materials by such application..
In applying the above-described solutions of baryta or strontia and of silica
in order to fix colours to the surfaces of stone, brick, slate, wood, cement,
stucco, mortar, clay, plaster of Paris, whitewash, and colourwash, Igenerally
adopt the following plan:-I mix the paint or other coloured preparation to
be used with a hot solution of baryta or strontia in water containing two or
more per cent. of such hydrate to the proper consistence for working, and
having applied this mixture to the surface to be coloured I give it time to
become nearly dry, I then apply to such surface either by means of a syringe
or brush, or in any other convenient way, a solution of silica in water con-
taining two or more per cent. of dry silica, I repeat the application of
solutions of hydrate of baryta or strontia and of silica until the colours
are fixed.
In the employment of solutions of baryta or strontia and of silica for the
various purposes of hardening, preserving, and waterproofing stone and other
materials, as herein-before recited, no corrosive acids and unnecessary or
hurtful soluble salts are introduced into the stone, but two substances only,
silica and an earthy base, which by their union within and upon the surface of
the stone or other material form an insoluble protective silicate, and no soluble
efflorescent or deliquescent salt.
Having now described the nature of this my said Invention, and the manner
in which the same is to be performed and carried into effect, I would have
it understood that I do'not claim the exclusive use of the processes by which
the solutions of baryta, of strontia, and of silica are made; nor do I claim
the exclusive use for the purpose of preserving or hardening stone, and for
the other purposes herein-before recited of the said solutions in water of
baryta, of strontia, or of silica, whether they be applied singly or in any
combination not herein-before described; but I claim and desire secured to
me by the before in part recited Letters Patent,―
Firstly, the exclusive use of a solution of silica in water when preceded or
followed by a solution of baryta or strontia in water, that is to say, the
successive or consecutive employment of such solutions as applied to any
of the herein-before recited purposes of my said Invention according to the
processes and after the manner here within described.

page_text: And, secondly, I also claim the exclusive use of the mixture of a solution
of silicate of potash or soda, with sulphuric, hydrochloric, or other common
and suitable acid (and which mixture may be regarded as an impure solution
of silica) preceded or followed by a solution of baryta or strontia as applied
to any of the purposes of my said Invention.
In witness whereof, I, the said. Arthur Herbert Church, have hereunto
set my hand and seal, this Twenty-fifth day of July, in the year of
our Lord One thousand eight hundred and sixty-two
ARTHUR HERBERT CHURCH. (L.S.)
Signed, sealed, and delivered by the
said Arthur Herbert Church, in
the presence of
HENRY FRA. CHURCH,
9, Bedford Row, Middlesex.
Solicitor.