IMPROVEMENTS IN THE MANUFACTURE OF PORTLAND CEMENT."
Year: 1880

page_text: LETTERS PATENT to Daniel Spence Ward Dawe, of Brading, Isle of Wight,
in the County of Southampton, Chemical Manure Manufacturer, for an
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF PORTLAND
CEMENT."
PROVISIONAL SPECIFICATION left by the said Daniel Spence Ward Dawe
at the Office of the Commissioners of Patents on the 21st October 1880.
DANIEL SPENCE WARD DAWE, of Brading, in the Isle of Wight, in the County
"IMPROVEMENTS IN
of Southampton, Chemical Manure Manufacturer.
MANUFACTURE OF PORTLAND CEMENT."
THE
My Invention consists of a process or processes of manufacture for converting the
fossil limestones and fresh water marls found in the eocene geological deposits of
the Isle of Wight.
I combine in certain proportions the said limestone and marl so that the mixture
shall not contain in chemical value more than seventy two or less than sixty five
per cent. of carbonate of lime.
I submit this mixture or blend to the following mechanical treatment :-
First. I dry the limestone and marl sufficiently to perinit of their being ground
to a powder fine enough to pass through a sieve having three thousand six hundred
ineshes to the square inch.
I afterwards submit the powder to a triturating process in a suitable mill, adding
sufficient water to render the mass plastic enough to permit of its being made into
bricks or other suitable forms. After thoroughly drying the bricks I place them in
a cement kiln with a suitable quantity of fuel, by which they are converted into a
clinkered mass.
The clinker thus obtained is then ground by the ordinary mechanical means
into a fine powder, and may be used for constructive or other purposes as a Portland
cement.
Second. I also, according to the physical consitution of the fossil limestone and
fresh water inari, resort to another method of mixing and reducing, maintaining,
however, the required proportion, as described in the first method, by treating
them with a sufficient quantity of water in a grinding mill until they are
accurately combined.
described.
I then dry and burn the parts in the manner before

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said .Daniel Spence Ward Dawe in the Great Seal Patent Office on the
21st April 1881.
DANIEL SPENCE WARD DAWE, of Brading, Isle of Wight, in the County of
Southampton, Chemical Manure Manufacturer, "IMPROVEMENTS IN THE
MANUFACTURE OF PORTLAND CEMENT."
My Invention consists of a process or processes of manufacture for converting
the fossil limestones and fresh water marls found in the eocene geological deposits
of the Isle of Wight.
I combine in certain proportions the said limestone and marl, so that the mixture
shall not contain in chemical value more than seventy two or less than sixty five
per cent. of carbonate of lime.
I submit this mixture or blend to the following mechanical treatment:-
First. I dry the limestone and mari sufficiently to permit of their being ground
to a powder fine enough to pass through a sieve having three thousand six hundred
meshes to. the square inch.
I afterwards submit the powder to a triturating process in a suitable mill, adding
sufficient water to render the mass plastic enough to permit of its being made into
bricks or other suitable forms. After thoroughly drying the bricks I place them
in a cement kiln with a suitable quantity of fuel, by which they are converted
into a clinkered mass.
The clinker thus obtained is then ground by the ordinary mechanical means into
a fine powder, and may be used for constructive or other purposes as a Portland
cement.
Second. I also, according to the physical condition of the fossil limestone and
fresh water marl, resort to another method of mixing and reducing, maintaining,
however, the required proportions, as described in the first method, by treating
them with a sufficient quantity of water in a grinding mill until they are
accurately combined. I then dry and burn the paste in the manner before
described.
Having now described the nature of my said Invention, and in what manner the
same is to be performed, I desire to claim,―-
The conversion of the fossil limestones and fresh water marls of the Isle of
Wight into a good marketable Portland cement.
'
In witness whereof, I, the said Daniel 'Spence Ward Dawe, have hereunto
set my hand and seal, this Twenty first day of April, in the year of our
Lord One thousand eight hundred and eighty one.
D SW DAWE (LS)
DSW DAWE (LS)