Improvements in the Manufacture of Plaster.
Year: 1893

page_text: Date of Application, 10th Jan., 1893
Complete Specification Left, 17th June, 1893-Accepted, 22nd July, 1893´
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Plaster.
I JOHN CALDWELL BLOOMFIELD of Castle Caldwell, Leggs, in the County of
Fermanagh Ireland, Gentleman do hereby declare the nature of this invention to be
as follows:-
The object of this invention is to produce a plaster which will dry with a
hardened polished face, superior in appearance to the finest Parian finish on
Portland cement at about half the cost.
In the manufacture of plaster in accordance with this invention I mix together in
a dry and natural state, finely ground raw shale, hydraulic or semi-hydraulic lime,
and sulphate of barytes, in various proportions according to the result required.
When a pure white plaster is required, I omit the raw shale and mix only hydraulic
or semi-hydraulic lime and sulphate of barytes. The componnd of shale, lime,
barytes, or of lime and barytes only, when mixed with water. This compound
when mixed with water may be applied after the manner of ordinary plasters, and
used as a fine stuff or top finishing coat for walls, ceilings, etc.
Dated this 10th day of January 1892
F. W. GOLBY,
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Plaster.
I, JOHN CALDWELL BLOOMFIELD of Castle Caldwell, Leggs, County
Fermanagh Ireland Gentleman do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-—
The object of this invention is to produce a plaster which shall dry with a
hardened polished face, superior in appearance to the finest Parian finish on
Portland cement at about one half the cost.
In the manufacture of plaster in accordance with this invention I mix together in
a dry and natural state, finely ground raw shale, hydraulic or semi-hydraulic lime
and barium sulphate (barytes) in various proportions according to the result
required. For an ordinary plaster having a blue tint I use equal parts by volume
or measure of the finely ground raw shale, hydraulic or semi-hydraulic lime, and
barytes, and to make the plaster more or less blue, I use more or less of the shale.
When a pure white plaster is required I omit the shale altogether and mix only
hydraulic or semi-hydraulic lime and barytes in about equal parts by volume or
measure. To this white plaster compound of hydraulic or semi-hydraulic lime and
barytes I may add any suitable coloring material, such as red ochre for example,
according the tint required.
The compound of hydraulic or semi-hydraulic lime and barytes, with or without
the addition of shale or other coloring material when mixed with water can be
applied after the manner of ordinary plasters and used as a fine stuff or top
finishing coat for walls, ceilings and for other purposes to which plasters are
applicable.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
(1) A plastering compound consisting of hydraulic or semi-hydraulic lime, and

page_text: barium sulphate (barytes) with or without the addition of a coloring material
substantially as described.
(2) A blue tinted plastering compound consisting of hydraulic or semi-hydraulic
lime, barium sulphate (barytes) and finely ground raw shale substantially as
described.
Dated this 17th day of June 1893.
F. W. GOLBY,
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.