AN IMPROVED MODE OF MANUFACTURING CEMENT
Year: 1854

page_text: LETTERS PATENT to Henry Young Darracott Scott, of Queen's Terrace,
Woolwich, n the County of Kent, Captain in the Royal Engineers, for
the Invention of "AN IMPROVED MODE OF MANUFACTURING CEMENT."
Sealed the 29th September 1854, and dated the 4th April 1854.
PROVISIONAL SPECIFICATION left by the said Henry Young Darracott
Scott at the Office of the Commissioners of Patents, with his Petition,
on the 4th April 1854.
I, HENRY YOUNG DARRACOTT SCOTT, of Queen's Terrace, Woolwich, in the
County of Kent, Captain in the Royal Engineers, do hereby declare the nature
of the said Invention for "AN IMPROVED MODE OF MANUFACTURING CEMENT" to
be as follows:-
In manufacturing cement according to my improved process, I take lime, or
sub-carbonate of lime and river mud or fine clay, in certain proportions, and
subject them when intimately mixed to pressure, to form the mixture into
cakes. These cakes I expose to a moderate red heat, and afterwards grind
them to a powder. The cement thus produced is to be mixed with water when
required to be used.
The advantages gained by this mode of operation over the ordinary methods
of proceeding are, a more rapid and active action between the constituents of
the cement, resulting from the closer proximity of their particles.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed by
the said Henry Young Darracott Scott in the Great Seal Patent Office
on the 4th October 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
YOUNG DARRACOTT SCOTT, of Queen's Terrace, Woolwich, in the County of
Kent, Captain in the Royal Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by IIer Letters
Patent, bearing date the Fourth day of April, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself. Her heirs and successors, give and grant unto me, the
said Henry Young Darracott Scott, Iler special licence that I, the said
Henry Young Darracott Scott, my executors, administrators, and assigns, or
such others as I, the said Henry Young Darracott Scott, my executors, admi-
nistrators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "AN IMPROVED MODE OF MANUFACTURING CEMENT," upon the
condition (amongst others) that I, the said Henry Young Darracott Scott, by
an instrument in writing under my hand and seal, 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 Henry Young Darracott Scott, do hereby
declare the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement (that is to say):-
―:
The object of this Invention is to obtain a more perfect chemical action than
heretofore between the constituents of artificial cement during their calcination,
and thereby to improve its qualities as to colour, plasticity, or tenacity for
moulding purposes, and durability in water works. In carrying out this
Invention I take lime, and add thereto any siliceous compound readily
attainable, such as river mud or clay, in proportions dependent on the natural
cement or hydraulic lime it is intended to imitate; thirty-five hundredweight
of lime to thirty hundredweight of the siliceous compound, giving good results
for ordinary purposes. These substances I reduce, either with or without the
assistance of water, to an impalpable powder, and intimately mix together; I

page_text: then place this compound in iron moulds, and submit it to hydraulic or other
pressure, sufficiently powerful to give solidity to the compound. The cakes
thus obtained I remove to a kiln, and subject them to calcination after the
ordinary manner of burning cements, regulating the degree of heat to which
the cakes are to be subjected according to the nature and relative amounts of
the constituent substances, but using considerably less fuel, as the lime con-
stituent is here present in the state of quick lime instead of carbonate. After
this calcination I reduce the cakes to a powder, which may then be packed in
barrels ready for the market. By manufacturing cement in the above described
manner, I find that the chemical change effected during the calcination of the
constituents of the cement is more complete and uniform than when the ordinary
method is employed, which improvement is due to the close proximity of the
constituent particles produced by the hydraulic or other pressure.
In some cases I may find it convenient to add the lime constituent to the
siliceous earth in the state of chalk, and to effect the conversion of the chalk
into lime, by driving off its carbonic acid during the operation of calcining the
mixed materials solidified by pressure. When this plan of operating is adopted
the temperature of the kiln must be greater, and the calcination of longer
duration than is required for the above-described process, or equal to that
at present employed for burning the natural cements of similar composition.
The proportions of the ingredients which I prefer are from sixty to sixty-five
hundredweight of chalk to thirty hundredweight of clay or other siliceous
compounds.
Having now described my Invention of an improved mode of manufacturing
cement, I wish it to be understood that under the above in part recited Letters
Patent I claim, the employment of hydraulic or other mechanical pressure, in
the manner and for the purpose above set forth.
In witness whereof, I, the said Henry Young Darracott Scott, have here-
unto set my hand and seal, the Third day of October, in the year of
our Lord One thousand eight hundred and fifty-four.
Witness,
J. W. MOFFatt,
66, Chancery Lane.
HENRY Y. D. SCOTT. (L.S.)