Improvements in the Manufacture of Artificial Stone and Hard Compositions, applicable to Building and Paving Purposes, to Moulds for Cement Castings, to Safes, and to other articles and purposes.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Artificial Stone and Hard
Compositions, applicable to Building and Paving Purposes, to
Moulds for Cement Castings, to Safes, and to other articles and
purposes.
I, OLAF TERP of Parkfield House, Perry Vale, Forest Hill, London S.E.,
Engineer, 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 :-
-
Artificial stone and similar compositions as heretofore made have usually not
been much like natural stone and have generally had surface cracks, fissures and
discoloured or greasy spots.
Now according to my invention I produce artificial stone having the same
valuable qualities such as durability, resistance to atmospheric and other outward
influences, and also presenting the same beautiful appearance as natural stones, but
with greater hardness and in practice with any required degree of hardness. My
invention also comprises various stone like compositions having valuable properties.
The method of forming the solution which I employ is described in the Specification
of my Patent application dated 30th June 1892 and numbered 12175.
By means of a cementitious mixture made according to this invention I produce
artificial stones and compositions such for instance as artificial sand stone, veined
or other marble, mosaics, moulds for plaster of paris or cement castings, pavement
flags or entire pavements, stair steps, balustrades, grave stones and monuments,
figures, busts, columns, building materials and ornaments, wall and floor tiles and
non-conducting compositions for safes.
I produce a chloride solution consisting of chloride of calcium, chloride of
magnesium, chlorated water, hydrochloric acid and water in the following manner.
Imake two solutions indicated by I and II and use about the proportions
hereinafter mentioned.
of
To this are added 2% of pure hydrochloric acid of full strength and 1%.
chlorated water being a pure saturated solution of chlorine while constantly
stirred.
The chloride solution thus made is intimately mixed with what is well known
in Germany (and can be procured when required from Frankenstein in Silisia)
as bitter earth (Bittererde) with pigments if desired and with materials, such
as sand, quartz, peat or peat fibre, paper pulp, spent tan or other materials to make
up bulk, and all according to the material to be manufactured. The hardness of
the stone or composition can be made more or less by the use of more or less
hydrochloric acid,

page_text: It should be noted that the substance above termed bitter earth may be purchased
as a marketable article as stated but as it is a form of oxide of magnesia it may
be especially manufactured for the purposes of my invention though prefer in
practice to employ the bitter earth of commerce.
1. shall now enumerate examples of manufacture in which the aforesaid chloride
solution is employed as binding material.
1. Sandstone of a suitable character is made by mixing about 25% by weight
of the chloride solution, first with 25 per cent. of bitter earth and then with 50%
of sand with or without any suitable quantity of pigment according to the colour
desired. The composition is well mixed or kneaded till it assumes the consistency
of a thin even paste whereupon it is poured into the mould, open or closed as the
case may be, such moulds being made of plaster of paris cement, glue compound,
metal or other material, the interior of the mould. having been previously lightly
coated with oil, such for instance as rape seed oil.
When the composition has set and hardened, which takes about 10 to 15 hours,
the casting is taken out of the mould and left to dry at ordinary temperature.
I then brush it over with hydrochloric acid or equivalent acid in order to remove
the outer glassy scale and for the sand grains to shew on the surface, which then
presents the appearance of true natural sand stone. As soon as the casting begins
to feel rough the acid is rinsed off with cold water.
If the casting is ornamented with relief figures, flowers or the like and it be
desired that such ornaments should be prominent the ground only, or the prominent
parts only, are brushed over with hydrochloric acid; the parts not thus treated
will then retain their smooth surfaces which may be polished as desired, thus
presenting a handsome or suitable contrast to the rough parts which latter look
like sandstone.
2. Artificial marble is made from equal parts by weight of the aforesaid chloride
solution and-bitter earth the mixture produced being a nearly snow-white thin fluid
paste. If the marble is to be coloured and veined I take a small part of the
quantity of paste-like mixture required for a casting and add to it some colour; this
part is then by means of a spatula and gentle stirring added to the main quantity
in such manner that the coloured part becomes mixed in with it in streaks or
veins. In some cases the pigment may be introduced by means of saturated threads
in the manner well known. The mass is then carefully poured on an un-oiled glass
plate or other suitable perfectly smooth plate or in an un-oiled mould. When the
composition has set and hardened the casting is easily loosened from the plate or
mould and presents a smooth polished appearance.
In order to preserve this polished appearance I proceed as follows. After the
lapse of some hours the surface acquires a white coating which must not be wiped
off but the casting is put into a bath consisting of about 25% saturated solution of
chloride of calcium and 75% saturated chloride of magnesium solution.. After
being in this bath several hours the casting is removed and left to dry. As soon
as the chloride salts on the surface look quite dry which takes about 4 to 6 hours
the surface is rubbed with a soft rag and vaseline or paraffin oil whereby not
only the chloride salts but also the aforesaid white coating are entirely removed.
The white coating or sweat will however show itself the following days but in a
much less degree and it is rubbed off in the same way until after some days no more
white sweat appears.
The articles thus cast may be tables, mantel pieces shelves, stair steps and
numberless others either as slabs or in other shapes.
The main colour of the marble may be for instance white and the veins black
or dark or the main colour may be black with white or light veins. Or the marble
may be in various main shades of colour and the veins in contrasting colours,
all alike or varying, even as natural marble exists in many shades of main colour
and many different colours of veins.
To save material and to give artificial marble slabs and other articles a greater
strength I find it advantageons to first produce a thin layer of the plain or veined

page_text: marble of the marble cement or composition described and then finish with a
thicker layer of the composition mixed with much sand say about half of each.
The slab thus obtained has a marble face which is treated as described with
reference to the slabs or articles of entire marble.
3. Mosaic tables, wall tiles, floor tiles, stair steps and slabs for other purposes
are made in mosaic form or with patterns or designs on by fixing on a suitable
even surface wooden or metallic frames of the size of the required casting and
pour on within the said frame a mixture consisting of about 70% of marble or
other natural sand in various colours and sizes of grains and 15% of the aforesaid
chloride solution and 15% of bitter earth.
If for instance a round table is to be produced of about 1 inch thickness and
having a border and a central star then I make for the border a ring of thin sheet
zinc about 1 inch high and 6 or 8 cornered say 3 inches smaller than the outer
round frame and for the centre star I make a star shaped ring of a thin sheet zinc
strip about 1 inch wide. Having mixed, say, grains of basall or marble about
the size of a pin's head with the coloured cementitious material. I cast it in the
space between the outer frame and the polygonal ring, and also within the central
star ring. I then mix with some similar or otherwise coloured cementitious
material some marble grains, say, the size of a nut and fill therewith the space
between the star ring and the polygonal ring. The two rings are then carefully
lifted out whereupon the two kinds of composition will flow against each other
and unite all round but nevertheless preserve the central star pattern. In 10 to 15
hours the casting is ready to be removed and can be ground or polished like natural
Inarble.
4. Moulds suitable for casting in portland cement or plaster of paris are made
of a mixture of about 30% of the aforesaid chloride solution, 30% of bitter
earth and 40% of sand, this liquid and evenly mixed mass being poured over
the wooden or other pattern which has previously been coated with shellac
solution and well oiled. When the mould casting has set and hardened and the
pattern removed the mould is to be coated on the inside with shellac solution and
oil the same as moulds made of plaster of paris or various kinds of cement.
Because of their hardness and sharp contours these moulds are very much more
useful than the plaster moulds; they may also be kept in the open air and preserve
the sharp contours for years though frequently used.
5. Pavements may be made according to my invention and either in slabs or on
the spot where to be used. The mixture employed consists of about 70% of sand
of granite, basalt, quartz or other hard natural stone, 15 % of the chloride
solution and 15% bitter earth. Pigment may be added for any desired colour.
This pavement material is very durable and the slight difference in hardness of the
natural stone and the cement produces a good foothold
6. Panels, boards, skirting boards and the like are made by admixing about 40%
of the chloride solution and 20% of the "bitter earth "with 40% of sawdust,
wood wool, peat or peat fibre, paper pulp, spent tan or other similar cheap
materials. The composition may be simply cast within frames or pressed and of
course in any desired colour by admixture of earthy colours. Such panels or
other articles may be sawn the same as wood and joined to any other part by
means of nails or screws. They offer the advantage of absolute security against
burning and are of so close a texture as to be safe against the entry of vermin.
The same material or composition may be used for parquet flooring, rollers for
wringing and mangling machines and numerous other purposes.
7. Composition for safes is made from about 60 °
"。 emery, 20% of the chloride
solution and 20% bitter earth. This composition when cast in the spaces between
inner and outer plates of a safe is absolutely fireproof and resists steel drills and
other burglar's instruments.
It must be clearly understood that although I in the foregoing have indicated
certain proportions of the materials I use for mixing with my chloride solution
such proportions are merely given as suitable examples having regard to the

page_text: respective purposes indicated and they may be greatly varied according to the
character of stone or composition desired and the purposes for which they are
-employed.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
-claim is :-
First. The use of a solution consisting of chloride of calcium and chloride of
magnesium and of small proportions of hydrochloric acid and chlorated water
mixed with bitter earth such solution being mixed with the substances respectively
mentioned in the manner and for the purposes hereinbefore respectively described.
Second. The manufacture of castings of artificial white or plain marble and of
veined marble by employing the materials mentioned in the manner and for the
purposes substantially as described.
Third. The manufacture of castings in mosaic and other patterns substantially
as described.
Fourth. The manufacture of hard composition moulds for cement castings a d
the like substantially as described.
Dated this 30th day of June 1892.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.