Photographs and Tinted Drawings.
Year: 1885

page_text: Photographs and Tinted Drawings.
I, ERNEST DE PASS, of 68 Fleet Street, in the City of London, Fellow of the
Institute of Patent Agents, do hereby declare the nature of said Invention for
A PROCESS FOR COPPER PLATE AND RELIEF ENGRAVING FROM PHOTOGRAPHS AND
TINTED DRAWINGS, communicated to me from abroad by Arthur Simon Joseph
Miron, of 1, Boulevard Saint-Denis, Paris, France, Engineer to be as follows:-
This Invention has for its object a process for the production of engraved
copper plates, sunk or in relief, from drawings, even with blended tints (indian
ink and stippled drawings &c), or from proofs or photographic negative proofs
taken from nature or from objects to be reproduced.
This process is based on the transference, by means of a reproducing machine
of any kind, such as the ordinary portrait lathe, tracing, engraving, cutting
machines &c of the relief which, by the aid of the action of light on suitable
substances, may be obtained either by means of drawings, or by negative proofs,
the machine producing an engraving either on metal direct, or a lined or dotted
drawing, which it will, by known processes, be easy to transform into a sunk
engraving, or into a typographic negative proof.
The relief is obtained by insolating underneath the negative proof or the drawing,
a substance the solubility of which is susceptible of becoming modified under the
influence of light, such as Barbadoes tar or other resins, gum, gelatine or other
bichromated proteic substances, or by utilizing the property possessed by bichromated
gelatine of swelling more or less in water when it has been subjected to the action
of the luminous rays, or in fine, any other known means for attaining the same
end, such for example as the engraving of daguerreotypes. This relief-or its
moulding, according to the case-is supported on a perfectly flat bearing plate.
The machine in its essential parts is similar for all kinds of engraving; it
consists, as before stated, of a known kind of reproducing machine.
Let it be supposed that it is required to produce a relief by gelatine, by means
of a photographic negative proof, of a view taken from nature, a copper plate
engraving.

page_text: In this
I commence by producing a relief by means of insulated bichromated gelatine
placed on a very even supporting plate, and washing it with warm water.
relief the projections will correspond with the black parts of the pattern and they
will be in proportion to the intensity of the tinted parts. In the pure whites the
projection will be nil.
The machine, as is known, consists essentially of a table capable of receiving
two movements in a vertical direction whilst remaining exactly in the same plane.
Above this table is an oscillating lever carrying at one end a tracer, and at the
other a graver of V form, or a rotary conical cutter. Underneath the tracer is
the relief, and underneath the graver the plate to be engraved, both are in a plane
exactly parallel to the table which supports them.
The height of the tracer and that of the graver are regulated in such manner
that the tracer on being in contact with a pure white (that is to say the bearing
plate) the graver passes over without touching the surface of the plate to be
engraved.
If, under these conditions, a series of successive strokes be given, each time
displacing the table in a vertical direction, the graver operated by the tracer
which has risen or fallen according to the form of the relief it has traversed, will
have traced on the plate to be engraved a series of parallel equi-distant lines,
unmarked in the white parts of the pattern, fine in the light parts, becoming wider
in the dark parts until in the black parts they join each other.
This collection of lines, seen at a good distance, will already give a representation
of the pattern. If, now upon causing the graver to perform a quarter of a revolu-
tion I regulate it so that the tracer being in contact with a pure white, the graver
will be over the plate to be engraved, at a height equal to half the height of the
culminating point of the relief, and if there be given a series of strokes perpendicular
to the first series whilst always displacing the table to the same extent at each
stroke, I shall have a fresh series of lines crossing the first series perpendicularly,
but existing only at those parts which correspond to the dark and black parts of
the pattern.
In effect, the graver which is operated by the tracer will, as a result of its
adjustment, only commence to reach the plate to be engraved when the tracer
shall have encountered portions of the relief more elevated than the horizontal
plane passing through the middle of the total height of this relief, that is to say
portions corresponding to the dark and black parts of the pattern.
This sunk engraved plate may furnish a proof for transfer on zinc which I can
transform into a typographic negative proof by known processes.
If I wish to obtain a reduced typographic negative proof I may operate on
a silvered plate, and after it has been inked take off a negative proof, or more
simply, I may substitute for the metallic plate, a plate of a somewhat soft black
substance whitened on the surface, and from the drawing produced by the graver
take off a negative proof of the desired dimensions. From this photographic
negative I may, by known means, obtain a typographic negative proof.
Under these conditions, instead of producing on a flat surface a line drawing
by means of a graver operated by a tracer according to the reliefs furnished by the
negative proof, I may draw direct on the whitened black plate, this plate having
previously been moulded on a counter proof of the relief, and the triangular graver
being fixed after adjustment. It is clear that the line traced by the graver will
equally be nil in the white parts, fine in the light grey, and the maximum of width
in the black parts-as by reason of the relief of the plate, which relief increases
with the intensity of the tone of the pattern or drawing-the graver being fixed
will penetrate well into the projections and consequently make a wider line.
The photographic negative proof taken from this latter drawing will, as in the
preceding case, allow of the production of a typographic negative proof in copper
plate engraving.
To engrave or draw in dotted lines, I substitute for the graver or rotary cutter
fixed to the end of the lever arm, a rotary cutter capable of rising a certain distance

page_text: and of returning to its initial point of adjustment a certain number of times deter-
mined by each centimetre of travel performed by the table. This motion is
obtained by means of an electro magnet, the current of which is opened or closed
by a commutator actuated by the fly wheel of the screw producing the travelling
motion of the table. This clectro magnet thus successively attracts or releases an
armature forming part of the tool holder. Therefore, instead of continuous lines,
I obtain interrupted lines which are the wider and nearer together according as
they correspond to a darker part of the pattern.
To engrave or draw in equidistant lines of equal thickness. Let it be supposed
that, instead of the oscillating lever, a small fixed bar is employed carrying at one
end the tracer, and at the other end the graver, both moveable in a vertical slide
way, a slight spring on the tracer from above downwards and on the graver from
beneath upwards. The travel is suitably limited for the one and the other by a
stop. The relief is metallized, by means of graphite for example, and every time
the tracer encounters the relief a circuit will be closed and an electro magnet will
act on the graver, will bring it back to its stop point, and the graver will penetrate
the plate to be drawn upon a small constant quantity. This being granted, and
the height of the culminating point of the relief taken as 1, the stop of the tracer
will be adjusted in such manner that it passes just over but without touching the
part corresponding to a pure white, so that upon executing the strokes no line will
be traced in the parts corresponding to the white parts of the pattern, but the
plate will receive them in all the other parts. These lines will be parallel, equi-
distant, and of the same thickness. For the second stroke, perpendicular to the
first, the stop of the tracer is so arranged that this latter shall be at a height above
the tracer equal to one fourth the total height of the culminating point of the
relief. I thus obtain a series of lines perpendicular to the first lines, but they will
be interrupted in the parts corresponding to the white and light grey parts of the
pattern. Let a conversion of 45° in the horizontal plane be executed on the relief
and on the plate, marking them exactly so that the same points under the tracer
and the graver correspond, then adjust the tracer over the white parts, at a height
equal to half the height of the culminating point of the relief. This stroke will
give a fresh series of lines crossing the first lines at an angle of 45°, and not being
marked in the parts corresponding to the white, light grey and grey parts.
Finally by giving a fourth stroke perpendicular to the third, in adjusting the
tracer to two thirds of the total height of the culminating point of the relief a
fourth series of lines is obtained perpendicular to those of the third stroke and
which will be unmarked in the parts corresponding to the white, light grey, grey,
and dark grey parts.
To engrave in relief, the operation is begun with a relief obtained from an
inverted positive in which the projections will consequently be so much the more
pronounced according as they correspond to the lighter parts of the pattern,
A mould may also be taken from a relief obtained from a reversed negative.
This being stated in operating with the machine arranged for sunk copper plate
engraving, the cutter will trace lines the wider and deeper according as the tracer
shall correspond to a lighter part of the pattern. In the purely white parts these
lines must come quite together, that is to say, the surface of the plate must be
completely removed. Upon giving a second stroke perpendicularly with a fresh
adjustment of the cutter to a half height, the shades will still be made clearer and
the more so as they shall be less deep.
It is well understood that all these kinds of engraving may be executed not only
on plane surfaces but also on surfaces to be revolved such for example as cylinders.
In this case the arrangement is modified as follows:-The relief with a surface
equal to that of the cylinder is placed on the table. The cylinder independent of
this table is mounted by its shaft on the transfer frame carrying the table and
parallel to the motion. Its upper generatrix is in the plane of the table and in
that of the tracer and of the cutter,

page_text: After the drawing of each line the cylinder turns on its axis to the extent of an
angle, such that the line being traced by the cutter is at the same distance from
the preceding one as are the courses consecutively travelled over by the tracer
through the displacement of the table. This angular displacement is effected by
means of an endless screw engaging with a toothed wheel connected to the cylinder
by a driver.
.
To give a perpendicular stroke the transfer motion becomes the displacement
motion and reciprocally as in the preceding cases.
This method of engraving is particularly applicable to rollers for printing on
fabrics and on coloured papers, leather, etc., equally as well as to plates.
Further, it is easy to operate on several cylinders at a time and engrave them
from a single drawing.
In all the preceding cases the tool carrying apparatus may ascend for the return
of the table after the execution of every line.

page_text: Photographs and Tinted Drawings.
I, ERNEST DE PASS, of 68 Fleet Street, in the City of London, Fellow of the
Institute of Patent Agents, 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, that is to say :-
This Invention relates to a process for the production of copper plate and relief
engravings from ordinary drawings, drawings with blended tints or shades, colour
washed drawings, stump drawings and the like, or from photographic proofs or
negatives taken from nature, or from any object required to be reproduced.
This process is based on the transfer or reproduction, by means of any suitable
reproducing machine, such as an ordinary engravers' lathe, tracing, engraving,
reducing and carving machines, and the like, of the relief which is obtained, by the
action of light upon suitable substances, either from drawings or from negatives,
these machines producing an engraving directly on metal, or a drawing made of
continuous or dotted lines, which may then be easily transformed, by any well
known means, into a copper plate engraving or a typographic negative.
The relief is obtained by insolating underneath the negative or the drawing, a
substance, the solubility of which is capable of being modified under the influence
of light, such as bitumen of Judea, or other resins, gum, gelatine or other bichro-
mated proteic substances, or by utilising the property possessed by bichromated
gelatine of swelling more or less in water when it has been subjected to the action
of luminous rays, or lastly, any other known means for attaining the same object,
such for example as the engraving of daguerreotypes.
This relief or its moulding, according to the case-is supported by a perfectly
flat bearing plate.
The reproducing machine used is not modified in its essential parts, whatever
may be the class of engraving required. Any well known kind of reproducing
machine will answer the purpose.
When it is required to produce, by means of a photograpic negative, a relief with
gelatine, of a view taken from nature, for copper-plate engraving, I form such
relief by means of insolated bichromated gelatine placed on a well planed supporting
plate and I clean it by washing it with warm water. In this relief, the pro-
jecting parts correspond with the black parts of the pattern or model, and are
in proportion to the intensity of the tinted parts. In the blanks the projections
are nil.
The machine consists essentially of a table which, while remaining in the same
plane may have imparted to it a reciprocating motion and also a lateral feed motion.
Above this table there is an oscillating lever carrying a tracer at one end, and at
the other a graver, of a V form, or a rotary conical cutter. Below the tracer is the
relief, and under the graver is the plate to be engraved, both being in a plane
exactly parallel to that of the table which supports them.
The height of the tracer, and that of the graver, are regulated in such manner
-than when the said tracer is in contact with a blank (that is to say, with the

page_text: bearing plate) the graver passes over the surface of the plate to be engraved
without touching it.
If, under these conditions, a series of successive strokes be performed the table
being moved after each stroke in a direction at right angles to its travel the graver
operated by the tracer, which has risen or fallen according to the form of the relief
travelled over, will have traced on the plate to be engraved, a series of parallel
equidistant lines, unmarked in the blanks of the pattern, fine in the light tones and
increasing gradually in breadth in the dark tones, until they come into contact in
the black parts of the pattern.
This collection of lines, seen at a certain distance, gives, already a representation
of the pattern. If now upon causing the graver to accomplish a quarter of a revo-
lution, I regulate it so that the tracer being in contact with a perfect blank, the
graver is placed upon the plate to be engraved at a height equal to half that of the
highest point of the relief, and there be further given a series of strokes per-
pendicular to the first series, whilst constantly shifting the table to the same
extent at each stroke, a fresh series of lines will be obtained, and will cross the
first series perpendicularly, but will only be formed at those parts which correspond
to the dark and black parts of the pattern.
The graver which is operated by the tracer will, by reason of its adjustment,
only reach the plate to be engraved, when the tracer travels over portions of the
relief more elevated than the horizontal plane passing through the middle height of
this relief, that is to say, portions corresponding to the dark and black parts of the
pattern..
This sunk engraved plate may furnish a proof for transfer on zinc, which can be
transformed by well known processes into a typographic negative.
When a reduced typographic negative is required, I operate on a silvered plate,
and after it has been inked, I take off a negative, or more simply substitute for the
metallic plate, a plate of a somewhat soft black substance whitened on the surface,
taking off from the drawing produced by the graver, a negative of the desired
dimensions. From this photographic negative, I am able to obtain, by well known
means, a typographic negative.
Under these conditions, instead of producing on a flat surface a drawing by
means of a graver operated by a tracer, according to the reliefs furnished by the
negative, I may draw direct on the whitened black plate, this plate having pre-
viously been moulded on a counter proof of the relief, and the triangular graver
being fixed after adjustment. It is clear that the line traced by the graver is nil
in the white parts, fine in the light grey, and has a maximum of breadth in the
black parts, as by reason of the relief of the plate, which relief increases with the
intensity of the tone of the pattern or drawing,-the graver being fixed penetrates
well into the projections and consequently forms a wider line.
The photographic negative, taken from this latter drawing, will, as in the
preceding case, allow of the production of a typographic copper plate engraving.
To engrave or draw in dotted lines, I substitute for the graver or rotary cutter
fixed to the end of the lever arm, a rotary cutter capable of rising a certain distance
and of returning to its initial point of adjustment a certain number of times
determined by each centimetre of the course travelled by the table. This motion
is obtained by means of an electro-magnet the current of which is closed or opened
by a commutator actuated by the fly-wheel of the screw imparting a motion to the
table. This electro-magnet thus successively attracts or releases an armature
forming part of the tool-holder. Hence, instead of continuous lines, I obtain
interrupted lines, which are more or less wide, and in close proximity to one
another, according as they correspond to a more or less dark part of the pattern.
To engrave or draw in equidistant lines of equal thickness, a small fixed bar
carrying at one end the tracer, and at the other end the graver, both moveable in a
vertical slide is substituted for the above mentioned oscillating lever. The tracer
and the graver are both provided with a spring, and their travel is limited by a
stop. The relief is metallised by means of plumbago for example, and every time

page_text: the tracer encounters the relief a circuit will be closed and an electro-magnet will
act on the graver, and bring it back against the stop, the said graver penetrating
the plate to be engraved upon, a small constant quantity.
Now the height of the culminating point of the relief being taken as 1, the stop
of the tracer will be adjusted in such manner that it passes over without touching
the part corresponding to a blank, so that upon a stroke being completed, no line
will be traced in the parts corresponding to the blank parts of the pattern, but the
plate will receive them in all the other parts. These lines are parallel, equidistant,
and of the same thickness. For the second stroke perpendicular to the first, the
stop of the tracer is so arranged that this latter shall be at a height above the said
tracer equal to one fourth that of the highest point of the relief. I thus obtain a
series of lines perpendicular to the first lines, but missing in the parts corresponding
to the blank and light grey parts of the pattern. Let a conversion of 45° in the
borizontal plane be made by the relief and by the plate, arranging them so that
the same points under the tracer and the graver correspond, the tracer being then
adjusted over the blank parts, at a height equal to half that of the highest point
of the relief. This stroke will produce a fresh series of lines crossing the first lines
at an angle of 45°, and missing in the parts corresponding to the white, light grey
and grey parts. Finally by giving a fourth stroke perpendicular to the third, in
adjusting the tracer at a point having a height equal to three quarters that of the
highest point of the relief, a fourth series of lines perpendicular to those of the
third stroke is obtained, while missing in the 'parts corresponding to the blanks,
light grey, grey and dark grey parts of the pattern.
the
A representation is thus produced, the different shades of which are as shewn on
wing domin
To engrave in relief, the operation is started with a relief proceeding from an
inverted positive in which the projections will consequently be more or less
prominent according as they correspond to lighter or darker parts of the pattern.
A mould may also be taken from a relief obtained from a reversed negative.
This being so, in operating with the machine arranged for copper plate engraving,
the cutter will trace lines the width and depth of which will vary in proportion to
the lightness of the part of the pattern over which the tracer travels. In the
blank parts, these lines would be joined together, that is to say, the surface of the
plate would be completely removed. Upon imparting a second stroke, in a
perpendicular direction, while re-adjusting the cutter to a half height, the shades
will be made lighter and the more so as they will be less deep.
It is well understood that all these kinds of engraving may be executed not only
on plane surfaces, but also upon surfaces of revolution, such as cylinders, for
instance. In this case the arrangement is modified as follows:-The relief having
a surface equal to that of the cylinder is placed on the table. The cylinder
independent of this table is mounted by its shaft on the transfer frame carrying
the table and parallel to the direction of the motion. Its upper generatrix is in
the plane of the table and in that of the tracer and of the cutter.
After each line, the cylinder turns upon its axis describing an angle such that
the next line traced by the cutter is at the same distance from the first as are the
courses consecutively travelled over by the tracer through the displacement of the
table. This angular displacement is effected by means of an endless screw gearing
with a toothed wheel connected to the cylinder by a feather or key.
When imparting a perpendicular stroke, the transfer motion is converted into a
displacement motion, and vice versa, as in the preceding cases.

page_text: This method of engraving is applicable to rollers for printing on fabrics, coloured
papers, leather, and the like, as well as to plates.
It is easy to operate on several cylinders at a time and engrave them from a
single drawing.
In all the preceding cases the tool-holder carriage may be raised to allow for the
return of the table after each line.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim, as communicated to me by my foreign correspondent, is
1. The herein described process for the production of copper plate or relief
engravings from drawings, even from those having blended tints (colour washes
and stump drawings) or from proofs or photographic negatives taken from nature,
or from subjects to be reproduced, substantially as set forth.
2. The employment of the relief in gelatine, or similar substance, obtained by
means of the pattern under the influence of light, for producing with the aid of
the mechanical means described, copper plate or relief engravings on metallic
surfaces, or a drawing in continuous or dotted lines for photographic printing to be
reproduced by engraving on metal, either copper plate or in relief, by well known
means, it being understood that the mechanical arrangement herein before described
may be varied, also that all known machines for tracing, reducing, engraving and
carving may be likewise employed.
3. The special application (of the process described, to the execution of printing
rollers or plates used for printing on fabrics, paper, leather and the like.