AN IMPROVEMENT IN PREPARING AUTOGRAPHIC PRINTING PLATES, TOGETHER WITH AN IMPROVEMENT IN THE ART OF AUTOGRAPHIC PRINTING IN WHICH THE USE OF SAID PLATES IS INVOLVED
Year: 1879

page_text: LETTERS PATENT to William Thompson Howard, of the City of Baltimore,
United States of America, for the Invention of "AN IMPROVEMENT IN PREPARING
AUTOGRAPHIC PRINTING PLATES, TOGETHER WITH AN IMPROVEMENT IN THE
ART OF AUTOGRAPHIC PRINTING IN WHICH THE USE OF SAID PLATES IS
INVOLVED."
Sealed the 12th August 1879, and dated the 4th June 1879,
COMPLETE SPECIFICATION filed by the said William Thompson Howard at
the Office of the Commissioners of Patents on the 4th June 1879.
WILLIAM THOMPSON HOWARD, of the City of Baltimore, United States of
of America. "AN IMPROVEMENT IN PREPARING AUTOGRAPHIC PRINTING PLATES,
TOGETHER WITH AN IMPROVEMENT IN THE ART OF AUTOGRAPHIC PRINTING IN
WHICH THE USE OF SAID PLATES IS INVOLVED."
This Invention is founded on the known fact that a mercurial surface will resist
or repel printers' ink. I am aware that heretofore Inventions in printing and
analogous arts have been made in which this fact has been availed of, but in one
class of such Inventions wherein unengraved plates have been used the galvanic
battery has been called into requisiton in the preparation of the printing surface of
the plates, while in the other class engraved plates, which it is the object of my
Invention to avoid, have been used. The plates used in these Inventions have, as
far as I have been informed, been made in two ways. In the first mode silver has
been deposited by galvanic action on a copper plate as a medium to promote a union
between the said plate and a coating of mercury. In the second mode the engraved
plates, after the engraved lines have been filled with wax or other substance, have
been rubbed with metallic mercury. The first class of such Inventions is unsuitable
for use in the hands of persons unskilled in electro-plating; while the second class
involve, as above stated, the use of an engraved plate which cannot be applied to
the purposes for which my Invention is designed. The simplicity of my improve-
ments adapts them to the general uses of merchants, professional men, and subordi-
nates in counting rooms, as indeed all to whom the rapid, cheap, and exact repro-
duction of manuscript is of value.
My Invention relates, first, to providing an unengraved printing plate having an
inked inscription thereon with a mercurial surface without the use of electrical

page_text: apparatus and without the necessity of rubbing the mercury on said plate, which
would obliterate or deface the inked inscription. In carrying out this part of my
Invention I take an ordinary copper plate and transfer thereto from a paper written
in ink the writing or inscription to be reproduced in print and then apply to the
printing surface of the plate one or more of the salts of mercury in solution, whereby
an amalgamated or ink resisting coating is given to the uninscribed portion of said
plate.
The Invention relates, secondly, to the process of autographic printing in which
the preparation and use of the above described plates are involved. I carry out
the process as an entirety as follows:-I write or otherwise inscribe in transfer ink
on paper the desired writing or inscription to be reproduced in print, then transfer
the same in reverse to an ordinary copper plate by pressure, then remove the transfer
sheet, then apply by immersion or a saturated pad or brush to the surface of the
plate bearing the inked design one or more of the salts of mercury in solution to
form a mercurial or amalgamated coating to the uninscribed portion of said plate,
then dry the plate and burnish it, then pour upon the amalgamated coating a small
quantity of metallic mercury, which is diffused over the surface of the plate, and,
finally, roll it up in ink and print therefrom after the manner of lithography.
It is obvious that the same effect may be obtained by writing the subject to be
printed in reverse with ink on the plate before treating it with the mercurial
solution, but it is equally apparent that great inconvenience would arise therefrom
to persons unskilled in the art of engraving or etching.
I am aware that it is not new to coat metals with mercury by means of a solution
of the salts of mercury, but I am not aware that an unengraved ink-inscribed plate
has been thus treated with the view of obtaining a printing surface, or with any
other view whatsoever.
Having thus described and ascertained the nature of my said Invention, what
I claim is substantially as follows :-
:
1st. The within described mode of preparing an autographic printing plate, con-
sisting in transferring thereto from a paper written in suitable ink, the writing or
inscription to be reproduced in print and then applying to the inked surface of said
plate one or more of the salts of mercury in solution, whereby an amalgamated or
ink-resisting coating is given to the uninscribed portion of said plate.
2nd. The within described improvement in autographic printing, consisting in
writing or otherwise incribing in ink on paper the desired writing or inscription to
be reproduced in print, then transferring the same in reverse to an ordinary copper
plate by pressure, then removing the transfer sheet, then applying to the surface of
the plato bearing the inked design one or more of the salts of mercury in solution
to form a mercurial or amalgamated coating to the uninscribed portion of the plate,
then drying the plate and burnishing it, then pouring upon the amalgamated coating
a small quantity of metallic mercury, and, finally, rolling up the plate in ink and
printing therefrom.
In testimony whereof, I have hereunto set my hand and affixed my seal, this
1 1970
Witnesses,
Jos. G. CUMMINS.
W. C. NICHOLLS.
WILLIAM THOMPSON HOWARD. (L.S.)