A NEW OR IMPROVED MANUFACTURE OF WHITE CEMENT.
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said John Caldwell Bloomfield
at the Office of the Commissioners of Patents on the 19th February 1880.
JOHN CALDWELL BLOOMFIELD, of Castle Caldwell, County of Fermanagh, Ireland.
"A NEW OR IMPROVED MANUFACTURE OF WHITE CEMENT.'
"
My Invention relates to the manufacture of a white cement, applicable as a
coating to walls or ceilings, my object being to produce at small cost a material
which, setting almost immediately after its application, furnishes a dry white
surface ready at once to receive colour or decoration, and renders a structure
immediately fit for occupation.
For this purpose I employ as the base of the cement a limestone which burns
milk white, and having calcined it I add about five per cent. of sulphate of lime,
such as plaster of Paris, or of other sulphates that are not of a deliquescent
character, or of mixtures of these. I reduce the product to powder; with this
I thoroughly mingle about its own weight of ground flint or silica, adding first
about half of the silica ground to an impalpable powder, and afterwards the other
half of the silica ground fine. The mixture thus produced at little cost constitutes
a white cement, which is applied in the usual way.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Caldwell Bloomfield in the Great Seal Patent Office on the
17th August 1880.
JOHN CALDWELL BLOOMFIELD, of Castle Caldwell, County of Fermanagh, Ireland.
"A NEW OR IMPROVED MANUFACTURE OF WHITE CEMENT."
My Invention relates to the manufacture of a white cement, applicable as a
coating to walls or ceilings, my object being to produce at small cost a material
which, setting almost immediately after its application, furnishes a dry white
surface ready at once to receive colour or decoration, and renders a structure
immediately fit for occupation. For this purpose I employ as the base of the
cement a limestone which burns milk white, and having calcined it I add about
five per cent. of sulphate of lime, such as plaster of Paris, or of other sulphates that
are not of a deliquescent character, or mixtures of these. I reduce the product to
powder; with this I thoroughly mingle about its own weight of ground flint or
silica, adding first about half of the silica ground to an impalpable powder, and
afterwards the other half of the silica ground fine.
The mixture thus produced at little cost constitutes a white cement, which is
applied in the usual way.
.
The proportions mentioned above may be somewhat varied; thus the sulphate
may be added to the calcined limestone in quantity varying from three to seven
per cent., and the weight of silica may be somewhat greater or less than that of the
mixture to which it is added; but practically I find that the proportions stated
produce a good serviceable cement.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim,―
The manufacture of white cement, substantially as herein described.
In witness whereof, I, the said John Caldwell Bloomfield, have hereunto set
my hand and seal, this Twelfth day of August, in the year of our Lord One
thousand eight hundred and eighty.
J. C. BLOOMFIELD (L.S.)
J. C. BLOOMFIELD (L.S.)