Improvements in the Manufacture of Terra Cotta Ware.
Year: 1891

page_text: Date of Application, 13th Oct., 1891
Complete Specification Left. 13th Jan.. 1892-Accepted. 13th Feb.. 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Terra Cotta Ware.
We,
WILLIAM STEPHEN EDWARDS of 6 New Houses, Acrefair, Ruabon in
the County of Denbigh, Terra Cotta Maker, and JAMES WESLEY EDWARDS of
1 Nelson Terrace Rhosddu, Wrexham, aforesaid County, Grocer do hereby declare
the nature of this invention to be as follows:-
"
On terra cotta ware there forms a light colored substance, which is a blemish,
known in the trade as scum. By observation we find that this scum forms
during the evaporation of the moisture from the clay. We are aware that there
are several methods used with some success for the removal of the scum after its
formation on the clay. Our process is for the prevention of the formation of the
scum by the application of a hermetic coating upon the face of the clay before
evaporation is completed, thus preventing evaporation taking place from the
surfaces coated. We apply coal-tar as a coating to the face of the clay while the
clay is wet, leaving those surfaces which are not intended for exhibition entirely
free of such coating and so allow the evaporation to take place through those
surfaces. We apply coal tar whilst it is hot, so that it may be applied thinly, for
we find it adheres better, than when applied cold. The coating we allow to remain
upon the clay until it is burnt off in the kilns during the baking.
Dated this Twelfth day of October 1891.
WILLIAM STEPHEN EDWARDS.
JAMES WESLEY EDWARDS.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Terra Cotta Ware.
We WILLIAM STEPHEN EDWARDS of 6 New Houses, Acrefair Ruabon in
the County of Denbigh, Terra Cotta Maker, and JAMES WESLEY EDWARDS
of 1 Nelson Terrace, Rhosddu Wrexham aforesaid County, Grocer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
On terra cotta ware there forms a light colored substance which is a blemish
known in the trade as scum. By observation we find that this scum forms during
the evaporation of the moisture from the clay. We are aware that there are
several methods used with some success for the removal of the scum after its
formation on the clay. Amongst the processes now in use for removing the scum
are those of scouring the surfaces intended for exhibition with sand paper, brushes,
sponges and water.
These processes are injurious to the smooth finished surfaces of the terra cotta,
because they leave the surfaces rougher.
Our process is for the prevention of the formation of the scum, by the application
of a hermetic coating upon the face of the clay before evaporation is completed,
thus preventing the evaporation taking place upon the surfaces coated. We apply
coal tar as a coating to the face of the clay while the clay is wet leaving those
surfaces which are not intended for exhibition entirely free from such coating, and
so allow the evaporation to take place through those surfaces. We apply coal tar
whilst it is hot so that it may be applied thinly, for we find it adheres better than
when applied cold. The coating we allow to remain upon the clay until it is
burnt off in the kilns during the baking.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that which we
claim is :-
By the application of a hermetic coating upon the face of the clay whilst the
clay is wet and before evaporation is completed allowing evaporation to take place
through those surfaces which are not coated only. Scum is prevented from
forming on those surfaces which are coated, this process originated by us.
Dated this Eleventh day of January 1892.
WILLIAM STEPHEN EDWARDS.
JAMES WESLEY EDWARDS.