New Method for the Production of Hard Stones, especially Lithographic Stones.
Year: 1898

page_text: Date of Application, 4th Mar., 1898-Accepted, 6th Aug., 1898
New Method for the Production of Hard Stones, especially
Lithographic Stones.
PAUL ARTHUR WINKLER, Merchant at Leipzig, Empire of Germany, 20, Auen
Strasse, 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:-
My invention relates to a method for the production of hard stones which on
account of their composition, formation and particuliarities, are equal to the
natural limestones in every respect and especially proper for lithographic stones,
which are therefore the best substitute for the former, without possessing the
flaws and defects, which are found in every real stone.
The method is founded on the basis that burnt lime slaked with water to
calcium-oxyd-hydrat, is pressed by means of hydraulic power into metal moulds,
dried, and afterwards carbonated with wet carbonic acid.
The mould filled with the above-mentioned substance, is exposed to the pressure
of 1500 to 2500 pounds per square inch by means of a hydraulic press and left
there for a longer or shorter time according to the hardness or softness of the
stones desired to be produced.
Then the stones, so moulded are dried, in a room with a temperature of about
25 degrees of Celsius, and afterwards supplied with liquid carbonic acid, till
the stones are completely saturated with it, so that a stone, which before the
treatement weighed 100 pounds, will afterwards weigh 200 pounds. The trans-
formation into limestone takes place gradually, beginning at the outside.
In the way explained, I have succeeded in producing stones of the first quality,
which are qualified for lithography, and are equal to the best natural stones.
Indeed, the artificially-produced stones are, in every respect, better than the
real stones, being free from the flaws, which too often are found in the natural
stones. My product contains neither craks, nor veins, nor any other impurities
belonging to the natural stones. One great advantage of my process is, that it
is possible for me to give the stones any shade of colour desired, by adding real
colour during the process of slaking.
Being able to produce lithographic-stones of the best quality, I may, of course,
in the same way produce artificial limestones, suitable for any
other purpose.
According to the employment of a more or less finely grained material, any
grain can be given to the product. The mould, which is used during hydraulic
pressure, must be so made, that the air can escape.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is;-
CLAIMS.

page_text: Time into moulds, then drying, and then saturating the same with liquid carbonic
acid, substantially as described.
2, Method of producing limestones, which method consists in adding real
colour to burnt lime during the process of slaking, then pressing the slaked lime
into moulds, then drying, and then saturating the same with liquid carbonic
acid, substantially as described.
3, 1ne new and improved method of producing limestones, substantially as
described and set forth in the foregoing specification.
Dated this Second day of March 1898
EDUARD
LOEPER,
Leipzig, 3, Grimmaische Strasse 3, Agent.