AN IMPROVED METHOD OF ENGRAVING
Year: 1854

page_text: LETTERS PATENT to Auguste Edouard Loradoux Bellford, of 16, Castle
Street, Holborn (City), London, Patent Agent, for the Invention of "AN
IMPROVED METHOD OF ENGRAVING."-A communication.
Sealed the 26th January 1855, and dated the 29th July 1854.
PROVISIONAL SPECIFICATION left by the said Auguste Edouard Loradoux
Bellford at the Office of the Commissioners of Patents, with his Petition,
on the 29th July. 1854.
I, AUGUSTE EDOUARD LORADOUX BELLFORD, of 16, Castle Street, Holborn
(City),London,Patent Agent, do hereby declare the nature of the said Inven-
tion for "AN IMPROVED METHOD OF ENGRAVING " to be as follows, viz.:-
This Invention consists in producing engravings of all kinds in relievo by a
galvanic current, the plate or metallic object desired to be engraved being
covered with the design in some suitable ink, and substituted for the soluble or
feeding electrode usually employed in any pile whatever.
The motallic deposit taking place at the negative pole, the positive pole loses
a'corresponding quantity of metal, which is taken from those parts of said
metallic object which are not covered with ink or drawn upon. The solution
used for the pile may be of any suitable kind, such as cupric sulphate, nitrate,
chloride, more or less diluted. Although any ink may be used, still I prefer
[Price S11

page_text: lithographic ink; but to render it insoluble I take albuminous water to
dissolve it in instead of pure water. After the plate or other object has been
drawn upon, it is heated to about 212 degrees Fahrenheit, so as to coagulate
the albumen and render it insoluble; it is then suspended in the bath, which
may have any suitable degree of strength, and left to be corroded in the
uncovered parts, which will generally be accomplished in about twenty minutes.
This galvanographic process is applicable to reproducing all pen or pencil
drawings or designs on all metals or alloys, brass, gun metal, iron, steel,
copper, tin, and especially on zinc. One of the most useful applications of
this Invention will certainly be to engraving the copper rollers used in calico
printing.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Auguste Edouard Loradoux Bellford in the Great Seal Patent
Office on the 27th January 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, AUGUSTE
EDOUARD LORADOUX BELLFORD, of 16, Castle Street, Holborn, City, London,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of July, in the year of our Lord
One thousand eight hundred and fifty-four, in the
year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Auguste Edouard Loradoux Bellford, Her special licence that I,
the said Auguste Edouard Loradoux Bellford, my executors, alministrators,
and assigns, or such others as I, the said Auguste Edouard Loradoux
Bellford, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
METHOD OF ENGRAVING," a communication, upon the condition (amongst
others) that I, the said Auguste Edouard Loradoux Bellford, by an instru-
ment in writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next. and immediately after the
date of the said Letters Patent.

page_text: NOW KNOW YE, that 1, the said Auguste Edouard Loradoux Bellford,
do hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This Invention consists in producing engravings of all kinds in relievo by a
galvanic current, the plate or metallic object desired to be engraved being
covered with the design in some suitable ink, and substituted for the soluble or
feeding electrode usually employed in any pile whatever. The metallic deposit
taking place at the negative pole, the positive pole loses a corresponding
quantity of metal, which is taken from those parts of said metallic object which
are not covered with ink or drawn upon. The solution used for the pile may
be of any suitable kind, such as cupric sulphate, nitrate, chloride, more or less
diluted. Although any ink may be used, still I prefer lithographic ink ; but
to render it insoluble I take albuminous water to dissolve itin instead of pure
water. After the plate or other object has been drawn upon, it is heated to
about 212 degrees Fahrenheit, so as to coagulate the albumen and render it
insoluble; it is then suspended in the bath, which may have any suitable degree
of strength, and left to be corroded in the uncovered parts, which will generally
be accomplished in about twenty minutes.
This galvanographic process is applicable to reproducing all
pen or pencil
drawings or designs on all metals or alloys, brass, gun metal, iron, steel, copper,
tin, and especially on zinc. One of the most useful applications of this Inven-
tion will certainly be to engraving the copper rollers used in calico printing.
Having thus given a brief sketch of this Invention, I will now proceed to
enter upon the details by which the principles above stated may be successfully
carried cut in practice.
First, as to preparing the plates:-If the number of copies to be taken off
the plate do not exceed a few thousand, zinc plates may be used; for a greater
number of copies a harder metal, such as copper, iron, steel, tin, or an alloy,
such as gun metal, yellow brass, & must be used. The plate having been
chosen, it is carefully polished in any suitable manner; but if it is desired that
the engraving should imitate pencil drawings, a proper grain must be given to
the surface of the plate. After the plate has been polished it may at once be
drawn upon; however, if it is desired to produce an engraving of superior
fineness and nicety, it will be found preferable to impart to the surface acertain
dullness, as the lines are liable to widen out on a perfectly bright or polished
surface. This is effected by strewing on the plate pummice stone reduced into
au inpalpable powder; this is moistened with a little water, and next a small

page_text: zinc roller is rolled over the plate in all directions until the required shade be
obtained. Care is to be taken not to carry the dulling process too far, as this
is objected to by draughtsmen; however, there is no reai inconvenience in so
doing, since by some practice it will be easy to appreciate the intensity of the
shades and to draw accordingly. The dullness thus obtained results from the
formation of a suboxyd, and hence many means may be employed for obtaining
the same, viz., oxydizing agents, brown oxyd of lead, alkalis, &c. I, however,
prefer using a zinc roller above mentioned.
The design may be made either with lithographer's ink or with a varnish
that is insoluble in water. If lithographic ink is used, the plate, before being
immersed in the engraving bath, is first subjected to several preliminary
operations, to be described herein-after, but with varnish it may immediately be
engraved. I would, however, observe, that lithographic ink is preferable to
varnish, not being liable to run, and allowing the artist to draw with a greater
freedom of stroke; but even when using said ink the blank spaces may be
subjected to corrosion immediately, provided the ink be first made insoluble in
water, which is most conveniently done by diluting it with albuminous water.
The plate drawn upon with this ink is exposed to a temperature of about 212
degrees Fahrenheit, when the albumen will coagulate and efficiently protect
the ink from water. When, however, the drawing is made with ink dissolved
in pure water, as usual, or with a lithographic pencil, or else when it is taken
off a drawing on stone or paper, the next operations will be as follows:-The
plate is acidulated in a very dilute solution of acid, or, as is practised by zinco-
graphers, by means of a decoction of nut galls, to which is added a certain
quantity of nitric acid. For this purpose, six or eight parts weight of nut gall
being put into 150 parts water, the whole is boiled down to about one-third
of its weight, which is then filtered, and as much nitric acid added to it as the
nature of the work may require. This solution is spread over the plate by
means of a sponge or a smooth brush, and is left upon it during a length of
time, varying according to the kind of work. The plate is then thoroughly
washed and gummed, after which the drawing is removed by means of essence
of turpentine; the plate is washed in gum water, and is inked with the fol-
lowing composition, either by means of a roller or with a rag:-Yellow bees'
wax, eight parts; essence of turpentine, eight parts; linseed oil, six and one-
half parts; lamp black, six and one-half parts; tallow, four parts; gum lac,
four parts; colophany, two parts; Burgundy pitch, two parts; white pitch,
two parts. These ingredients must be thoroughly mixed together; also I
do not strictly confine myself to the proportions shewn, as they may be varied

page_text: indefinitely without materiallyaffecting theaction ofthecompound, the essential
feature of which is being insoluble in water, and easily put on by means
of a roller.
As to the composition of the bath, it must in general gauge about 20 or 25
degrees on the alkalimeter; for the finer kind of drawings, however, solutions
of 15 to 20 degrees are best used. For engraving on copper, any soluble
copper salts may be applied, either separately or in combination with other
salts. Among the salts that may thus be employed I shall only name the
acetate,sulphate, nitrate, and chlorides of copper, the double cyanide of copper,
and potassium; the double salts, such as sulphates of copper and of iron, orany
other of the soluble salts. For engraving on brass, sulphates of copper
and
of zinc are dissolved in proportions which correspond with the composition of
the alloy. If, for instance, the brass contains 64 parts of copper, 34 parts
of zinc, and 2 parts of lead, the corresponding quantities of salts to be dis.
solved in water will be 250 parts of sulphate of copper, and 147 parts of
sulphate of zinc; when nitrates or acetates are used, a little nitrate or acetate
of lead may suitably be added to the solution. Strictly speaking, brass plates
may be engraved in a bath containing copper salt only, but then the bath
becomes soon impure and mixed with zinc. The bath for engraving on
zinc, iron, steel, is prepared with soluble salts of zinc and iron, and the most
suitable salts will be found to be the sulphates, nitrates, chlorides, double
cyanides, and acetates. Plates of gun metal or bronze are engraved in a bath
prepared with a mixture of chlorides of copper and of tin.
When the drawing and bath have been thus prepared, the latter according
to the nature of the metal as shewn,the plate is covered at the back with wax,
or with a protecting varnish, and is suspended at the positive pole of a pile or
battery. For this purpose, any battery may be used that produces a constant
or alternating current, or a combination of constant and alternating currents.
I would, however, suggest, that Daniell's battery is preferable, on account of
its constant action; Bunsen's charcoal battery,on account of its economy; and
Wollaston's may be used with advantage when the design can soon be termi-
nated. At the negative electrode,a plate for receiving the metallic precipitate,
or else a metallized mould of a medal, &, may be placed. After half an
hour'saction, or thereabout, the plato with the drawing is taken out, and after
being washed in water it is inked by means of a lithographer's inking roller,
with the composition above described, which is rubbed up with essence of
turpentine. The fine and close lines will thus merge into one another, the big
lines being again insulated and protected from the action of the acid. The

page_text: plate is then subjected to a gentle heat, by means of a balneum mariæ or sand
bath, so as to cause the ink to run down along the edges of the lines and
prevent or fill up any gap or break in the lines. The plate is placed again in
the etching bath, and in another hour, about, the fine parts may be covered
again with ink as before. This operation is repeatedly carried on until there
only remain the great blanks to be hollowed out. The line or dark parts of
the drawing are then covered by means of a brush with light varnish, or with
the ink above described, diluted with turpentine, and the blank parts may
then be corroded to the depth required. It will be easy in practice to find
what length of time a given plate will require for thus engraving in relievo,
this time varying according to the power of the battery, the fineness of the
lines, and the extent of blank spaces. Thus, an engraving with very fine lines
requires half an hour at most, but a common engraving may be finished and
have all the blank spaces deeply corroded in a few hours, and in general any
kind of plate with any size of blanks may be terminated in the course of one
day. The above-described system of galvanographic engraving may be applied
instead of wood engraving generally, and especially to reproducing in an
economical way lithographs, penand pencildrawings,old engravings, and letter-
press; it may also be used for engraving music, labels, maps, surveying plans,
designs for fabrics,embroidery papers, stereotyping of any kind, and also for
producing calico printers' blocks and rollers, at a small expense.
Having thus described the nature of this Invention, and the manner in
which the same is or may be carried into effect, I wish it to be understood
that I do not claim the use and application of the positive pole to hollow
engraving; but what I claim as novel,and secured by the herein-beforo in part
recited Letters Patent, is,-
First, the application of voltaicor galvanic electricity to engraving or etching
in relievo, as described.
Second, the method of giving a particular tint to metals or alloys by means.
of pummice stone, water, and a zinc roller, as described.
Third, the method of imparting the same tint by passing over the metallic
plate brown oxyd or peroxyd of lead diluted with water.
Fourth, fixing the drawing by mixing lithographic ink with albuminous
matter and by subjecting it to heat.
Fifth, protecting the raised parts with fine lines, by repeatedly passing over
it au inking roller, which caused said lines to merge into one another.
Sixth, the use of a. cero-resinous ink, as described, instead of common
lithographic ink.

page_text: Seventh, protecting the lines, by causing the ink to run along the edges and
down the sides of each line, by exposing the plate to heat after being inked.
Eighth, applying galvanographic etching or engraving to making calico-
printing blocks.
In witness whereof, I, the said Auguste Edouard Loradoux Bellford, have
hereunto set my hand and seal, this 27th day of January, in the year
of our Lord 1855.
A. E. LORADOUX BELLFORD. (L.S.)