The silver state. [volume] (Winnemucca, Nev.) 1909-1925, 1911-03-30
INGENIOUS DEVICE
FOR ILLUSTRATING

Cd. I. Murphy, st. Gall, Switzerland.)
Freiburg chemist, DR.. Edward Mer
tens, has recently perfected an ingeni
Gus invention which promises to revo
paper illustration. The Frankfurter
Zeitung of February 10, 1911, which
devoted editorial space to a deccrip-
tion of this inveition, contains sew
eral striking illustrations which show
at glance the results obtained, es-
pecially as regards tone and clearness,
by the new process.
From the article in the Zeitung it
appears that lew pressure printing of
illustrations, known as copper and steel
engraving, lithography and kindred
processes, may now be used in combi-
nation with the high pressure of the
rotary printing press, producing ex-
cellent results. Hitherto it was found
impossible to produce with the rotary
press, the only one capable of turning
out large editions in the shortest time
artistically effective pictures It has
been necessary to use for the printing
of illustrations zinc or copper plates
with deeply etched lines, and auto
types or blocks prepared by hand in
woodcut, and then transferred to met
al, for the printing of words in relief
type. For the new process of illustrat
ing, hollow iron cylinders are used,
provided with a thin layer of copper,
which, in spite of their weight, are
easily moved in the machine by means
of suitable contrivance. The copper
coverings, constructed by electrolvis,
form a medium for the picture
How Photographers Are Produced.
For the production of photographers
it is necessary to sensitize the surface
of the copper coverings, and this is
carried out automatically by a ma
chine on the Rolf system. The cylin
der revolves with every speed, and at
the same time a receptacle containing
sensitive fluid passes slowly in front
of it. From a nozzle attached to the
receptacle the sensitized solution falls
on the cylinder drop by drop. The
liquid is distributed over the surface
of the cylinder, and when dry forms an
even stratum, sensitive to light. For
the completion of the illustrations
photographs are needed. not mega
tives, but positves on films. These are
placed on the sensitized cylinder,
which is illuminated while turning by
electricity. In places where the film is
transparent the emulsion on the cylin-
der becomes insoluble in water, while
the covered places remain soluble.
Water is then poured over it, when
faithful copy of the Photographic view
appears on the cylinder, and this is
then rendered visible by coloring
matter and covered with asphalt var
nish. The now developed cylinder is
dried by hot air, and all is ready for
etching.
The cylinder is now coated with col
or and busted with asphalt and placed
for half an hour in bath of chloride
of iron, by which the finest lines are
closed. After a second short etching
it is again coated with rather larger
quantity of color and second dusting
of asphalt, till the closing of the
heavier lines has been effected. BY
continuing this process, during which
more and more color and asphalt are
added, the lightest middle tones are
closed, then the deeper middle tones,
and finally the lighter shades. There
remain open only those parts of the
picture which must appear darkest,
and must therefore have the greatest
depth.
AAe FrluClug FIOceSS.
The cylinder is then ingeniously
raised into the low-prssure machine,
no adjustment being needed before
printing. The most important of its
component parts are the colorimenters,
which Craze the cylinders from which
the pictures are printed in such a man.
ner that they scrape the color com
pletely, by an automatic arrangement,
from the parts of the roller which
must be left blank without becoming
blunt or injuring the engraving. The
color then remains in the deeply etch-
ed lines, from which it is transferred
to the paper by the action of spring
india rubber ,platen sujeeted to a
pressure of several thousand kilos.
This presses the paper into the engrav-
ing, from which it absorbs the ink.
The roll of paper runs as in the rotary
machine. 1t passes between the pic
ture- printing cylinder and platen. The
illustrated surface then passes onto
the rotary printing press to receive
the text. An indexing apparatus at
tached to the low-pressure machine
and rotary printing press serves to
bring pictures and text to the right
place AS matter of course, the low
pressure machine runs at exactly the