Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-09-29

ob1fquely, to a point Of requisite fiineness
Ihen there are a number of subordinate
tools, such as tiny doube-pronged forks Of
different widths, for marking parallel space
lines on the plate, T squares, burnishers and
scrapers, all used either to prepare the plate
for the work OF the graver or finish 1t UP
after that tool has been used. Copper and
steel plates are used. the former about a
sixteenth Of an inch in thickness and the
latter about double that thickness, and
these are procured from the manufacturers
In a nearly finished condition, and are fur
niShed In certain sizes.
When an engraver is given an order to
execute, say for a visiting card. he first
takes q copper plate that will suit the size
charcoal and oil and then bluffs 1t bright
with felt buffer. Upon the now highly
polished surface he slightly scratches, with
quill or pointed stick of wood. q sketch of
work must be in reverse on the plate. With
the little forks he scratches next guide
lines for the width and slant. Aided by q
magnifying glass supported In a frame he
graver, the name he has previously sketched
In. This is very delicate work and easily
shows the skill Of an expert In the
beauty and firmness Of the lines and curves
and in the formation and joints Of the let
tiers.
It is obvious that large plates require
more time. and. when the subject is an elab-
crate design or picture. the adoption OF q
means is often necessary to accomplish the
final result. The ruling machine is a deli
cately adjusted piece Of mechanism for pro-
ducing tints to initiate the fiat wash effects
in drawings The fine, close parallel lines
that most often make up the skies in an en-
graved picture, the background Of O por-
trait or the shading Of lettering and fancy
work in a letter heading. are done with a
ruling machine. Nearly all fine engraviigs
have some ruled tints upon them. and others
are almost entirely Of these ruled lines, as
for example. the steel engraved pictorial
calendars. SO frequently seen Of late on
office desks.
Bitten by Acid.
These tints are made by a diamond point
drawn over the plate by the machine. moved
by hand. The plate has been first coated on
both surfaces with an acid resisting wax.
and the diamond cuts through this coating
and exposes the surface Of the plate in
many fine lines. In order that the latter
may have depth enough in the plate to hold
ink, chemistry Is resorted to--that is, the
plate is subjected to bath of diluted acid,
which eats into the parts Of the waXed plate
exposed by the diamond. This whole opera
ton of coating with wax, ruling and biting
with acid, may be several times repeated
with resulting effects Of cross Matching
deeper tints and the like. In most instances
before this ruling has been done the greater
part Of the hand work has been either en-
graved or etched with the aid Of acid into
the plate. After the final retouching by the
engraver with his instruments the finished
plate goes from his hands TO the printer
Like the engraver. the printer may be ac-
cording to his abilities and ambition either
an expert or merely q skilled workman, but
in any cass he Is one who must exercise ex-
treme care in his occupation, or the easily
damaged plates he handles will quickly be
tell-tales Of his bunglinS.
For printing from engraved plates q
platen press Is used. 1t is made up of, first
q bed or slab Of iron, upon which the en-
graved plate rests. and this bed Is supported
between two iron rollers or cylinders-a
large one on the under side and q smaller
polished surfaced one at the top. The roll
ers are supported In an iron frame, at one