IMPROVEMENTS IN CEMENTS
Year: 1862

page_text: LETTERS PATENT to Charles Martin Westmacott, of 42, Noble Street, in
the City of London, for the Invention of "IMPROVEMENTS IN CEMENTS."
Sealed the 6th February 1863, and dated the 12th August 1862.
PROVISIONAL SPECIFICATION left by the said Charles Martin Westmacott
at the Office of the Commissioners of Patents, with his Petition, on the
12th August 1862.
I, CHARLES MARTIN WESTMACOTT, of 42, Noble Street, in the City of
London, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN CEMENTS," to be as follows:-
This Invention has for its object improvements in cements. For these pur-
poses lime is combined with unburnt limestone or chalk, suitably ground or
reduced to powder. The proportions may be varied, but when using very
good lime it is preferred to use at the rate of two measures of chalk or lime-
stone to one measure of lime. This compound may be employed alone, or com-
bined with sand, plaster of Paris, clay, or other materials, according to the
circumstances under which it is to be used. Cements thus produced may be
employed when making articles by suitable moulds, with or without the aid
of pressure, also for mortar or cements for building purposes,. and also for
plaster.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of August in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Martin Westmacott, Her, special licence that I, the said
Charles Martin Westmacott, my executors, administrators, and assigns, or
such others as I, the said Charles Martin Westmacott, my executors, admi-
nistrators, and assigns, should at any time agree with, and no others, from
time to time and at all times thercafter during the term therein expressed,
should and lawfully might make, usc, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN CEMENTS," upon the condition
(amongst others) that I, the said Charles Martin Westmacott, my executors
or administrators, 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 Charles Martin Westmacott, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object improvements in cements. For these pur-
poses lime is combined with unburnt limestone or chalk suitably ground or
reduced to powder. The proportions may be varied, but when using very
good lime it is preferred to use at the rate of two measures of unburnt chalk
or limestone to one measure of lime. This compound may be employed alone
or combined with sand, plaster of Paris, clay, or other materials, according
'to the circumstances under which it is to be used. I take the limo as it
leaves the kiln, and slack it in the usual manner; 1 then mix with it the
finely ground chalk or limestone in its natural state, with a sufficient quantity
_of water to bring it to the consistency of putty. The cement thus prepared,
'I employ for purposes for which the putty now made solely from lime is
used. If the cement is to be used for plastering or as mortar, I mix it with
sand or other similar extraneous matter; I then make the cement more liquid,
sufficiently so that the sand or other material when added may make it into a
mortar of proper. consistence for use, the mortar thus mixed can be used at
once, but recommend that it be kept in this damp state for a few days that

page_text: the lime may become the better impregnated with a proportion of the carbonic
acid contained in the carbonate of lime; the amount of sand I recommend
is the same that is usually added to common lime; or in place of producing
the cement in this manner, I in some cases proceed as follows:-I use the
lime finely ground instead of in the lump, and the chalk, limestone, or carbo-
nate of lime I desiccate thoroughly at about 200 degrees of heat Fahrenheit;
these materials I then mix without water, and keep the cement thus made in
a dry place for use. When the composition made according to this latter
process is required for use it can be slacked, and then sand or other similar
extraneous matter may be added, or the sand or other material may be added
when dry, and water applied afterwards. The above processes are those I use
for making my cement, which is suitable for mortar, plastering work, internal
and external cement, and to be used as a wash.
I would remark that in place of employing the lime as such, cements con-
sisting in great part of lime, such, for example, as Portland cement, may be
substituted for lime in its ordinary form, and in the case of Portland cement,
the proportions above mentioned may be usefully employed. Cements pro-
duced as above described may also be employed when making articles by
means of suitable moulds, with or without the aid of pressure.
I take my carbonated cement as above described, made by either method,
and thoroughly work it into a stiff paste, either with or without extraneous
matters, such as sand, road drift, broken stones, or broken calcined clay by
the aid of the machine commonly used for making mortar, or in a pug mill,
and I mould it into bricks, or articles of other required form, or I hammer it
into moulds by a powerful hammer, or press it in by great pressure; but if the
hammer or press, is used, less water must be put than when the composition
is moulded in a brick machine. When the articles are taken from the mould
I protect them for a few days from moisture, or the extremes of heat or cold,
I afterwards leave them to atmospheric influences.
In witness whereof, I, the said Charles Martin Westmacott, have here-
unto set my hand and seal, this Twelfth day of February, in the year
of our Lord One thousand eight hundred and sixty-three.
CHARLES MARTIN WESTMACOTT. (L.S.)