Year: 1888

page_text: We, JOHN BRUNTON of 13A Great George Street in the City of Westminster,
Civil Engineer and LEWIS GRIFFITHS of 82 Judd Street in the County of
Middlesex, Artificial Stone Maker, do hereby declare the nature of this Invention to
be as follows:-
The object of this Invention is to provide a manufacture of artificial stone which
is very durable and suited for any of the structural ornamental or other purposes to
which stone is adapted.
The artificial stone made according to this Invention consists of crushed granite or
like material such as slag, stone or gravel with Silicate of Potash or Soda and
Carbonate of Potash or Soda but preferably Carbonate of Ammonia together with
azotic acid or other equivalent acid which will combine with the Silicate and
Carbonate to form an insoluble Silicate of lime in the pores of the stone, there being
also used in the making of the stone hydraulic lime or Portland Cement and Sulphate
of lime which latter has the effect of making the product fire proof.
The granite or the like should be crushed say so as to pass through a gths of an
inch riddle but free from dust. This is mixed with a solution of Silicate of Potash or
Soda or both and then the hydraulic lime or Portland Cement can be added. Then
the Azotic acid and Carbonate of Ammonia or the like are dissolved and added and
afterwards the sulphate of lime but we do not limit ourselves to this precise order of
manipulation. The compound can then be pressed in moulds and when hard the
forms can be further hardened by means of a bath of an alkaline Silicate (preferably
silicate of Soda) and after immersion therein for a time they are taken out and dried
and are ready for use.
Coloring matters may be combined with the materials and metal bars or the like
may be embedded therein to give strength.
T .

page_text: We, JOHN BRUNTON, late of 13A Great George Street, but now of 7 Westminster
Chambers both in the City of Westminster Civil Engineer and LEWIS GRIFFITHS
late of 82 Judd Street in the County of Middlesex, but now of Park House,
Millwall, Manufacturer of Artificial Stone do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
The object of this invention is to provide a manufacture of artificial stone which is
very durable and suited for any of the structural, ornamental, or other purposes to
which stone is adapted.
The artificial stone made according to this invention consists of a mixture of
crushed granite, slag, limestone, or like material which will furnish lime or lime and
alumina (such as the soluble aluminous material formed by the decomposition of
feldspar in the granite) an alkaline silicate such as silicate of potash or soda and an
alkaline carbonate such as carbonate of potash, soda, or ammonia, but preferably the
mineral alkaline carbonate, an acid such as azotic acetic sulphuric or an equivalent
acid, hydraulic lime or Portland cement (common lime may be used if mixed with an
alkaline silicate say 15 parts of the latter to 98 of the former). If desired sulphate
of lime may be added to make the product fireproof.
The silicates carbonates and lime thus combine to form an insoluble carbonate of
lime and silicate of alumina as the cementing and consolidating material of the mass.
The following is the best way with which we are acquainted of carrying this invention
into effect.
The granite or the like is crushed so that it will pass through a ths of an inch
riddle and it should be as free from dust as possible. This is mixed with a solution of
silicate of soda, and then the hydraulic lime or Portland cement can be added.
The carbonate is then dissolved and added and then the acid, if acid be used, after-
wards if required the sulphate of lime may be added.
We do not limit ourselves to precise proportions, nor to the precise order of adding
the ingredients, we have found the following to answer well, the parts being by
weight. Crushed granite or the like 80 parts, alkaline silicate of a specific gravity
of 1150 th part, carbonate of ammonia th part, hydraulic cement 12 parts,
sulphuric acid th part, sulphate of lime 1 part, and water 5 parts. The compound
can then be formed in moulds (using hydraulic pressure if desired, although this
is not essential) and when hard the blocks or articles can be further hardened or
their hardening expedited by immersion in a bath of an alkaline silicate (preferably
silicate of soda or potash showing 680° on the hydrometer) and after immersion
therein for a time (usually for about 48 hours) they are taken out and dried and are
ready for use, usually in about 8 days.
Colouring matters may be combined with the materials or the stone after being
made a few days, may be tinted in different shades by impregnating it with metallic
salts and then adding a precipitating reagent. By means of salts of lead and copper,

page_text: with sulphuretted hydrogen, greys, browns, and blacks may be produced. Or the
stones may be dipped in hot solutions of metallic sulphates, carbonic acid is evolved
and the metallic oxide, combining with the sulphate of lime is deeply fixed in the
stone. In this manner sulphate of iron gives rusty tints, sulphate of copper a fine
green and mixed sulphates of iron and copper a chocolate. The double sulphates
thus formed increase the hardness of the stone.
Metal bars or the like may be imbedded in the material to give strength.
We are aware that silicates of potash and soda have been used for hardening
artificial stone and we therefore lay no claim thereto in itself alone.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :—
1st. The manufacture of artificial stone in the manner substantially as hereinbefore
described.
2nd. The manufacture of artificial stone by mixing together a material furnishing
lime or lime and alumina an alkaline silicate and an alkaline carbonate, substantially
as and for the purpose hereinbefore described.
3rd. The manufacture of artificial stone by mixing together crushed granite or the
like material or materials, which will furnish lime and alumina, an alkaline silicate,
a carbonate of an alkali, and an acid with or without sulphate of lime, súbstantially
as and for the purposes herein before described.
4th. The manufacture of an artificial stone from crushed granite or the like, an
alkaline silicate, a carbonate of an alkali, an acid hydraulic cement or lime and
sulphate of lime in or about the relative proportions herein before described.
Dated this 15th day of November 1888.
JOHN BRUNTON.
LEWIS GRIFFITHS.