IMPROVEMENTS IN SLABS OR PANELS FOR Decorative PurPOSES
Year: 1882

page_text: LETTERS PATENT to Alexander McLean of Belvedere Road in the County
of Surrey, Cement Manufacturer for an Invention of "IMPROVEMENTS IN
SLABS OR PANELS FOR Decorative PurPOSES"
PROVISIONAL SPECIFICATION left by the said Alexander McLean at the
Office of the Commissioners of Patents on the 10th February 1882.
ALEXANDER MCLEAN of Belvedere Road in the County of Surrey Cement
Manufacturer. "IMPROVEMENTS IN SLABS OR PANELS FOR DECORATIVE PURPOSES."
The object of this Invention is to produce an effective wall and ceiling decoration,
to be used in place of paper and other materials and which will have the
advantage of being washable.
To this end I employ slabs or panels of say eighteen inches square composed of
cement or plaster, either alone or mixed with other materials on which I form a
raised pattern.
The patterns I prefer shall be continuous or of a flowing character,
such as a foliated design.
For internal decoration I prefer to use Keenes or Parian cement which is mixed
with water in sufficient quantities to give when thoroughly worked up with a
trowel, the consistency of a thick batter. This batter is then put into series of
plain wooden moulds of the size of slab required, and about half an inch deep.
The mixed cement is spread out in the moulds and any superfluous material is
removed with a straight edge. The filled moulds are then left for from one to two
hours, according to the quality and nature of the ceinent, that the cement may set
to such an extent as to allow of the moulds being removed.
The slabs are then placed in an bydraulic or other press, and are subjected to
the pressure of a die in a suitable mould.
By the pressure the half inch slab will be compressed into a compact and solid
slab of a quarter of an inch, or thereabout in thickness with the pattern in relief,
all air-holes will be pressed out, a smooth even surface will be given to the slab, and
the operations of “ stoving,” filling in, and polishing will be rendered unnecessary.
When pressed the mould is removed and the slab is dried either by natural or

page_text: artificial means. The completed slab, which will ordinarily be of a pure white,
may then he ornamented by gilding or otherwise as taste may dictate; or the
cement may be mixed with a pigment in the first instance.
When applied to the wall the slabs may be secured by cement, plaster, or other
suitable adhesive material, to the first coating of mortar; or they may be nailed or
screwed to hattens or laths, for which purpose countersunk holes, to be afterwards
filled up, will be formed at the corners of the slabs, either during the compressing
operation or afterwards, as may be most convenient.
In applying the slabs to ceilings, they will be screwed to the joists. The nails,
screws, dies and other metal parts used in the manufacture or fixing of these slabs
or panels should be made of a metal which will not rust.
For external decoration I prefer to use Portland cement, which may be used neat
or mixed with sand or other material, and with a pigment as desired. The slabs or
panels will be affixed to the walls as before described, or in any other convenient
manner.
By means of these slabs or panels a cheap and effective decoration for external
purposes will be obtained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander MoLean in the Great Seal Patent Office on the
10th August 1882.
ALEXANDER MCLEAN of Belvedere Road in the County of Surrey Cement
Manufacturer. "IMPROVEMENTS IN SLABS OR PANELS FOR DECORATIVE PURPOSES "
The object of this Invention is to produce an effective internal decoration for
walls and ceilings to be used in place of paper and other material and which will
have the advantage of being washable.
To this end I employ slabs or panels of say eighteen inches by twelve inches
composed of Keene's Parian or similar cement either alone or mixed with other
materials on which I form by the aid of pressure a raised pattern. The pattern
I prefer shall have a continuous or Blowing character such as a foliated design.
For the purpose of my Invention I prefer to use Keene's cement which I mix
with water to make a "slip." The proportions which I find most suitable are two
parts by measure of cement to one part of water for a slab of eighteen inches by
twelve inches. These are mixed well together with or without a coloring matter
as may be desired.
The "slip" thus formed I pour into a mould and spread it evenly over the
bottom by any convenient means.
I next fill up the mould with dry cement and after levelling the surface apply
pressure thereto by means of a plunger shaped to fit the mould.
The effect of the pressure is to force the water contained in the slip towards the
upper surface and to bring it into contact with the dry cement which absorbs it
and under the action of the pressure combines with the slip and forms a hard solid
slab or panel.
The dry cement which I prefer to use for the backing is the coarser or second
quality of Keene's cement.
".
The amount of dry cement employed will be about the same as that used in
making the slip" and it is applied by means of a sieve, which has the double
advantage of letting the cement fall lightly and of spreading it more evenly than
by hand over the surface of the " slip."
By the employment of the slip for the face of the slab the formation of air holes
is avoided and I obtain a smooth even surface, the operations of "stoning" and
filling in being thus rendered unnecessary.
The completed slab after being allowed to dry for a few days may be further
ornamented by gilding or otherwise as taste may dictate, or it may be polished.
The pattern or design which will be in relief on the slab I form in the bottom
of the mould which may be of any suitable construction to allow of the slabs being
readily removed therefrom and the pressure of from fifty to one hundred pounds
per square inch is applied by means of
any suitable press.
The bottom of the mould I form of copper and the side pieces of gun metal. The
side pieces are held together by means of a gun metal chase provided on its under
side with pins or projections which enter corresponding holes in the side pieces.
In applying the slabs or panels to walls, the slabs may be secured by cement,
plaster or other suitable material to the first rough coating of mortar, or they may
be nailed or screwed to battens or laths secured to the walls. For the purpose of
nailing or screwing countersunk holes to be afterwards filled up with cement, will
be formed at the corners of the slabs either during the moulding or afterwards as
may be most convenient.
In applying the slabs to ceilings they will be screwed to the joists.
The nails and screws as well as the dies and other metal parts used in the

page_text: manufacture and fixing of these slubs or panels should be made of a metal which
will not rust.
Instead of making the slabs with an embossed pattern I may make them plain
in which form they may be used with advantage for many purposes for which
Mintons and other tiles are now employed as they can be made much larger.
Having now described my Invention of " Improvements in Slabs or Panels for
Decorative Purposes" and explained the manner of carrying the same into effect
I claim.
The inanufacture of slabs or panels for decorative purposes from Keene's Parian
or similar cement by the aid of pressure substantially as herein described.
In witness whereof I the said Alexander McLean have hereunto set my
hand and seal the Tenth day of August in the year of our Lord One
thousand eight hundred and eighty two.