AN IMPROVED MANUFACTURE OF ARTIFICIAL STONE OR EARTHENWARE APPLI- CABLE FOR BRICKS. TILES, RETORTS, RAILWAY SLEEPERS, & OTHER ARTICLES
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Francis Allen Kain at the Office
of the Commissioners of Patents, with his Petition, on the 15th August
1861.
I, FRANCIS ALLEN KAIN, of Redhill, Reigate Foreign, in the County of
Surrey, Operative Chemist, do hereby declare the nature of the said Invention
for "AN IMPROVED MANUFACTURE OF ARTIFICIAL STONE OR EARTHENWARE APPLI-
CABLE FOR BRICKS. TILES, RETORTS, RAILWAY SLEEPERS, & OTHER ARTICLES," to
be as follows:-
I crush to powder and sift small and refuse or other slate in combination
with other materials, and also vitrify the same in kilns at a high temperature;
aud I describe my process as under :-
Having obtained the slate (refuse or otherwise) I reduce the same to
powder by means of either steam or water power applied to rollers, crushers,
or stampers, I then sift the same through fine sieves, metallic or otherwise,
and to this powdered slate I then add fine sand, pulverized carbonate of
inagnesia, ground silica, and having well mixed these powders together, I add
wet clay and thoroughly incorporate the whole intimately together by means of
edge runners or other suitable machinery into a plastic mass, and then mould
or form any articles I desire by hydraulic or other pressure. The article being
formed is removed from its mould and allowed to dry for three days or
more as required; when sufficiently dry it is placed in a kiln that will stand a
vitrifying heat. The articles being introduced into the kilns, the fires of the
kilns are then lit, & a gentle moderate heat is allowed to continue for the
حيم

page_text: first 24 hours. I then raise the heat by continually adding additional firing
until I obtain a white heat, which I keep up until the firing in the kiln has
been going on for seventy-two hours, more or less, including the previous
twenty-four hours. The composition is by this time vitrified. I now close
the top of the kilns to prevent cold air entering them, and allow the fires to
die out. The kilns remain closed for upwards of a week, so that the articles
may be gradually & thoroughly cooled to prevent the cold air entering, and
thereby causing the goods manufactured to crack or fly.-
Secondly, I further apply a process of glazing the same, if required, as
follows: During the filling of the kiln with the articles that are to bevitrified
I place in the middle of the kiln a small round heap or mound of common
ordinary grey or white chalk or limestone (the same is converted into lime by
the high heat applied) and the gas that passes off from the chalk glazes any
article or goods on which I may desire to put a fine face or polish. I can
also glaze this vitrified moulded mass of slate material with either sugar of
lead or any other earthy body that will melt at the before-mentioned high
vitrifying heat.
The form of my composition is as under-Take of
Fine powdered slate
Carbonate of magnesia
Fine sand, powdered
Fine ground silica
24 pounds,
3 ounces,
...pounds,
5 ounces.
The whole of these to be thoroughly mixed together, and then add nine
pounds of wet clay of any description, and sufficient, water.to form the plastic
mass of a consistence suitable for moulding the articles required.
I do not confine myself to the exact proportions above given, nor to the
several matters employed, which may be varied, so long as in all cases a large
proportion of slate is retained, and the process of vitrifaction takes place..
Redhill Printed for His Uninsta