IMPROVEMENTS IN THE MANUFACTURE OF CEMENT, AND IN TREATING OR PREPARING COLOURING MATTER FOR CEMENTS
Year: 1856

page_text: LETTERS PATENT to William Oldham, of Southam, in the County of
Warwick, Cement Manufacturer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF CEMENT, AND IN TREATING OR PREPARING COLOURING
MATTER FOR CEMENTS."
Scaled the 4th November 1856, and dated the 10th September 1856.
PROVISIONAL SPECIFICATION left by the said William Oldham at the
Office of the Commissioners of Patents, with his Petition, on the 10th
September 1856.
I, WILLIAM OLDHAM, of Southam, in the County of Warwick, Cement
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF CEMENT, & IN TREATING OR PREPARING
COLOURING MATTER FOR CEMENTS," to be as follows:-
In the manufacture of cement from lias lime, heretofore the practice has
been to slack the lime, and subsequently to calcine, mix, and grind it with
clays or other suitable matters; and my improvements consist in first grinding
the white or blue lias limestone to a powder, either separately or with a
suitable admixture of clays; these materials, mixed previously or after grinding,
are then rendered plastic, and formed into suitable shapes, for the purpose of
burning or calcining, after which they are reduced to powder, by grinding to a
state suitable for cement, when it is fit for use. By this means the lias lime
is never slacked until it is used in the state of cement, when it will set better

page_text: & more readily under water, and will possess other properties as a cement
superior to that of ordinary manufacture. A further improvement consists in
reducing the lias lime by means of stones similar to millstones for grinding
wheat.
My improvements in preparing the coloring matter for cements consists in
grinding the coke, breeze, coal, coal slag, or charcoal, used for that purpose, to
a fine paste or powder while in a wet state, after which it is dried & reground
with the cement.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Oldham in the Great Seal Patent Office on the
5th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
OLDHAM, of Southam, in the County of Warwick, Cement Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by IIer Letters
Patent, bearing date the Tenth day of September, in the year of our Lord One
thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Oldham, Her special licence that I, the said William Oldham, niy
executors, administrators, and assigns, or such others as I, the said William
Oldham, my executors, administrators, 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 "IMPROVEMENTS IN THE MANU-
FACTURE OF CEMENT, AND IN TREATING OR PREPARING COLOURING MATTER FOR
CEMENTS," upon the condition (amongst others) that I, the said William
Oldham, 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 William Oldham, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-

page_text: In the manufacture of cement from lias lime, heretofore the practice has
been to calcine the limestone, and subsequently to mix and grind it with clays
or other suitable matters.
My improvements consist in first grinding the lias limestone to a powder,
either separately or with a suitable admixture of clays. The limestone and
clay, mixed either before or after grinding, the limestone is then rendered
plastic, and formed into suitable cubes or shapes for the purpose of burning cr
calcining, after which they are reduced to powder by grinding to a state
suitable for cement, when it is fit for use. By this means the lias lime is
never slacked until it is used in the state of cement, when it will set better and
more readily under water, and will possess other properties as a cement
superior to cement of ordinary manufacture. A further improvement consists
in reducing the lias limestone by means of stones similar to millstones used
for grinding wheat.
My improvement in preparing the colouring matter for cements consists in
grinding coke, breeze, coal, coal slag, or charcoal, used for that purpose, to a
fine paste or powder while in a wet state, after which it is dried and reground
with the cement. By this means I obtain a colouring matter which imparts a
more uniform and more permanent colour to the cement than can be produced
by grinding those materials dry and mixing them with the cement, as practised
heretofore.
In preparing cement according to my Invention I proceed as follows:-
The lias limestone is first broken by means of hammers into lumps, of a
size suitable to be submitted to further reduction by means of spiked rollers,
by which it is at first crushed; having been so crushed, it is further reduced
to powder by means of horizontal millstones. The clay is mixed with the lias
limestone either before or after grinding it to a powder. In case of mixing
the clay after grinding the limestone to powder, the clay should also be pre-
viously reduced to a powder, or to a state of pulp. Instead of clay, other
earthy material may be used, such as river and other suitable mud. The com-
pound is now rendered plastic, and moulded in bricks or other suitable forms
for subsequent operation; after moulding, the bricks or forms are allowed
to dry, and are then calcined in the ordinary manner of burning or calcining
argilaceous materials. After calcining the limestone and clay, or other material,
prepared and mixed as herein-before described, the calcined material is again
subjected to grinding between millstones, such as before mentioned, by which
it is reduced to a fine powder, which is used as a cement in the ordinary
manner. Previous to this second grinding I mix the colouring matter before
mentioned, in proportion according to the colour required, as is well understood

page_text: in the manufacture of cement. The proportions of limestone and clay or
other material used in this manufacture depends considerably upon the
qualities of the limestone and clay or other material used in the manufacture.
The proportions I find best adapted are about two parts of limestone to one
part of clay.
It will be observed, that the essential feature in my improved manufacture
is grinding lias stone to powder & mixing it with clay previous to calcining
the limestone, in contradistinction to first calcining the limestone and subse-
quently grinding it, as heretofore practised in the manufacture of cement.
Having described the nature of my Invention, and the manner in which the
same is to be performed, I declare that what I claim as my Invention, to be
secured to me by the herein-before in part recited Letters Patent, is,―
First, crushing and grinding lias limestone and mixing the same with clays
or other suitable materials previous to calcining in the manufacture of cement,
as herein-before described.
Secondly, I claim the use of horizontal stones, such as herein-before
described, for grinding lias limestone previous to calcining the limestone in the
manufacture of cement.
Thirdly, I claim wet grinding and preparing colouring matter for colouring
cements, as herein-before described,
In witness whereof, I, the said William Oldham, have hereunto set my
hand and seal, this Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
W. CLARK, Patent Agent,
53, Chancery Lane, London.
WILLIAM OLDHAM. (L.S.)