A MATERIAL OR COM- POUND OF MATERIAL, NOT HITHERTO SO USED, FOR PREVENTING DAMP RISING IN WALLS, AND FOR FREEING WALLS FROM DAMP, WHICH MATERIAL OR COMPOUND OF MATERIAL CAN BE APPLIED TO OTHER PURPOSES
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CHARLTON FORSTER, of Bartholomew Close, of the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Twentieth day of September, in
the fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Charlton Forster, Her especial licence
that I, the said William Charlton Forster, my exors, adñors, and assigns, or
such others as I, the said William Charlton Forster, my exors, admors, and
assigns, should at any time agree with, and no others, from time to time and at
all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention or discovery of "A MATERIAL OR COM-
POUND OF MATERIAL, NOT HITHERTO SO USED, FOR PREVENTING DAMP RISING IN
WALLS, AND FOR FREEING WALLS FROM DAMP, WHICH MATERIAL OR COMPOUND OF
MATERIAL CAN BE APPLIED TO OTHER PURPOSES;" in which said Letters Patent
there is contained a proviso obliging me, the said William Charlton Forster,
by an instrument in writing under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the same
is to be performed, and to cause the same to be enrolled in Her Majesty's

page_text: High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto bad, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Charlton Forster, do hereby declare the nature of my said Invention,
and in what manner the said is to be performed, are particularly described and
ascertained in and by the following statement, that is to say:-
I have discovered that a certain well-known material or compound of
material may be used with great advantage for preventing damp rising in
walls, and for freeing walls from damp, and to. other purposes herein-after
mentioned. This said material is the compound of the common clays or argil-
laceous earths now in general use for making bottles and other vessels to con-
tain liquids. Of this compound there are two kind, the one generally known
by the name of stoneware, naturally impervious to water and damp, and the
other of a courser and more porous texture, and which requires glazing to
render it impervious. The said material is to be formed into slabs, according
to the usual well-known processes of making stoneware or glazed earthenware.
These slabs are to be placed at the foundation of walls and buildings, and will
prevent the wet, damp, or moisture rising to the wall or building above them
from the carth beneath. They are also to be placed at the outer surface of
walls or buildings, and will prevent wet, damp, or moisture passing sideways
to the wall or building from the adjacent or surrounding, earth. They are
also to be placed to line walls or buildings, to prevent the appearance of wet
cr damp. They may be also used for making reservoirs, tanks,, cisterns to
contain water, and for paving, and for the copings of buildings. But I do not
claim the exclusive use of the said material, or compound of material, for the
last-mentioned purposes, but as to the manner in which the above-mentioned
Invention is to be performed. I make the slabs of earthenware or stoneware
. flat, and of about nine inches by eleven, sixteen, or twenty inches square, and
about one inch in thickness, with groove
and tongue, thus
"
or laps, thus
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on their edges, so as to fit, closely to each
other, and thereby give a better surface for the cement to hold the edges of
the slabs together, and to prevent effectually the wet, damp; or moisture
passing between the joints; and they may also be made of any other
dimensions to suit particular circumstances. In, using these slabs to prevent
the damp rising to walls or buildings from, the foundation or earth beneath, I
carry up the foundation wall a few, inches above the natural level of ground or
surface of carth that is intended to remain around it, and then put a layer of
these slabs over a bed, of mortar or cement-on-the top of the wall, so that the

page_text: slabs may form, an even surface of material impervious to any damp or
moisture. I then continue the wall or building to the required height upon
these slabs; and a wall so constructed will not be subject to any damp, wet,
or moisture from the foundation or earth beneath. For the purpose of pre-
venting any damp or moisture passing sideways to the parts of walls or
buildings below the surface of the earth, I fix, by the aid of nails or similar
fastenings, a layer of these slabs, cemented at the joints, against the outer
surface of the wall in contact with the earth.. In order to free walls from
damp in houses or buildings already constructed, I take out a layer of bricks,
or a layer of whatever material of which the walls or buildings are constructed,
just above the foundation wall or surface of earth around, and put in a layer
or layers of these slabs with cement, so as to present an impervious obstacle to
the damp or moisture rising from the foundation or earth beneath. The result
will be that the damp or moisture that was in the walls or buildings above the
layer of slabs will gradually evaporate, and the wall will become perfectly dry.
Should it be required to free the lower part of the foundation walls from
damp, it would be requisite to put the layer of slabs near the bottom of the
foundation wall, and likewise remove any carth or ground that may rest
against it, in order to place the slabs on the outer surface of the wall wherever
it may be liable to wet, damp, or moisture. By this means, the slabs placed
outside being impervious to wet, the wall or walls of the building will gra-
dually dry by the heat employed in the lower offices. The said material, or
compound of material, when formed into slabs of earthenware or stoneware,
as described, may be used as an outer coating to walls or buildings in
situations much exposed to rain, and will effectually prevent the damp passing,
as it will at times of prevailing rains. It may also be used effectually to pre-
vent the appearance of wet or damp, by placing the slabs with nails or cement
against the inner surface of the walls.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I wish it to be understood that I do not lay claim to
the Invention of the said material, or compound of material, my Invention in
regard thereto being confined to the formation of the said material, or com-
pound of material, into slabs, and to the use and application thereof for and to
the purposes aforesaid.
In witness whereof, I, the said William Charlton Forster, have here-
unto set my hand and seal, this Sixteenth of March, in the year of
our Lord One thousand eight hundred and forty-two.
WILLIAM CHARLTON (L.S.) FORSTER.

page_text: AND BE IT REMEMBERED, that on the Sixteenth day of March, in
the year of our Lord 1842, the aforesaid William Charlton Forster came
before our said Lady the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.