NEW OR IMPROVED CEMENTED LITHOGRAPHIC STONES
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the
8th September 1874.-A communication from abroad by Antoine
Marie Mayoux, of No. 64, Faubourg St. Martin, Paris, France.
I, WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand,
in the County.of Middlesex, Patent Agent, do hereby declare the naturė
of the said Invention for "NEW OR IMPROVED CEMENTED LITHOGRAPHIC
STONES," a communication to me from abroad by Antoine Marie Mayoux,
of No. 64, Faubourg St. Martin, Paris, France, to be as follows:-
The special object of this Invention is to multiply lithographic stones,
which although numerous are insufficient for the constantly increasing
demands of lithography and chromo-lithography.
This Invention consists in sawing the lithograpic stones (which are
much too thick, as the surface only is used, and this is subject to very
little wear) and replacing the thickness with cement, Portland cement,
known as "de la Porte de France à Grenoble." This cement has the:

page_text: property of the stone itself. Fixed upon a lithographic stone it assumes
(about three hours after application) the bardness of the stone, and
gives it sufficient consistency to resist the pressure of either hand or
steam press. The mixture is made of half cement, half sand, and the
sand should be first well washed, that is to say, should contain no
earth.
The mixture is made in small quantities at a time, moistening by
sprinkling gently from a watering pot with a rose. When the mixture
is complete the cement is placed on the stone, the surface upon which
it is applied being first thoroughly washed. It adheres to the stone and
gives the desired thickness, according to the size of stone, large stones
being of course made thicker than small one.
Any suitable cement may be used, and the equivalent for Portland
cement above mentioned is named simply because it has been employed
for this purpose with good results.
In conclusion, and in order that the principles upon which this
Invention is based may be thoroughly understood, I would here remark
that the attempts hitherto made to combine lithographic stones either
with another stone, with slate, or any kind of mortar have always failed
because in coating stone with stone sufficient adhesion is never obtained,
the points of contact being either too far apart or intercepted. Stone
thus prepared is always apt to break.
The attempts made with mortar have not been so numerous, but the
few that have been made have been still more disastrous, as their authors
taking no account of the laws of affinity have never succeeded.
This Invention is the result of a series of studies and experiments,
from which it has been ascertained that by reason of its texture the
lithographic stone being of a calco-argillaceous and slightly siliceous
nature can only assimilate with calcareous matters of the same mature,
and when treated in the summary mode above set forth, but which
explains itself to all acquainted with the art of lithography.
To sum up the advantages of this Invention are,—
1°. The application of a cement compressed and moulded directly on
to the stone to be prepared.

page_text: 2°. The assimilation of the cement used with the stone itself, this
assimilation resulting from its composition and affinity with the stone.
'
3. The possibility of giving to lithographic stones every desired
thickness.