IMPROVEMENTS IN CUTTING ENGRAVING METALS AND THEIR ALLOYS
Year: 1859

page_text: LETTERS PATENT to Jean Baptiste Henri Honoré Raymond Barre and
Jean Baptiste Marie Ernest Barre, of Paris, 27, Rue de Penthièvre,
Merchants, for the Invention of "IMPROVEMENTS IN CUTTING
ENGRAVING METALS AND THEIR ALLOYS,"
OR
Sealed the 28th February 1860, and dated the 5th September 1859.
PROVISIONAL SPECIFICATION left by the said Jean Baptiste Henri
Honoré Raymond Barre and Jean Baptiste Marie Ernest Barre at the
Office of the Commissioners of Patents, with their Petition, on the
5th September 1859.
We, JEAN BAPTISTE HENRI HONORÉ RAYMOND BARRE and JEAN BAPTISTE
MARIE ERNEST BARRE, of Paris, 27, Rue de Penthièvre, Merchants, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN CUTTING OUT OR
ENGRAVING METALS AND THEIR ALLOYS," to be as follows:-
Our Invention relates to the cutting out, engraving, or perforating of metals
and their alloys by a chemical process, and consists chiefly in covering (by the
aid of printing) the parts to be left intact with a fatty or resinous body, im-
penetrable to azotic acid, and leaving bare the parts which are desired to be
acted upon by the acid.
For example: Suppose that we wish to cut out a design on a plate of
copper, we first draw the design on a lithographic stone, and thenink the same
with a suitable mordant or adhesive medium, which may be composed as
Price T

page_text: follows-One half part of printer's mordant and one half part of copal oil
varnish, colored with black printer's ink. We then take an impression on
paper, and by the aid of a lithographic press or other pressure, we transfer the
same on to the copper-plate which we wish to engrave, and remove the paper
by slightly wetting the same, when the design will be found transferred to the
copper-plate. The design having been thus produced on the plate in the
mordant oradhesive medium is to be powdered with a resinous or fatty substance
impenetrable to azotic acid, which may be composed of two-thirds of a resinous
substance, and one-third wax, melted together and pulverized. The plate is
then heated and repowdered with resin only, and this operation is repeated
until a sufficient coating has been produced to resist the action of the acid
perfectly for a lengthened period. The plate is then to be submitted to the
action of azotic acid, which will attack and dissolve the uncovered parts, and
thus bite in or engrave the design, and if allowed to remain a sufficient length
of time the design will be cut out or perforated entirely through the plate.
We would here remark, that the above compositions are given as an example
only, and the nature and proportion of the different ingredients will vary
according to the nature of the metal or alloy of metals to be acted upon, and
from other circumstances; but full details of these variations will be given in
our Final Specification, in which we will also indicate the different applications
which can be made of the metallic plates when engraved or cut out, as above
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Jean Baptiste Henri Honoré Raymond Barre and Jean
Baptiste Marie Ernest Barre in the Great Seal Patent Office on the
3rd March 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JEAN
BAPTISTE HENRI HONORÉ RAYMOND BARRE AND JEAN BAPTISTE MARIE ERNEST
BARRE, of Paris, 27, Rue de Penthièvre, Merchants, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of September, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Jean Baptiste Henri Honoré Raymond Barre and Jean Baptiste
Marie Ernest Barre, Her special licence that we the said Jean Baptiste
Henri Honoré Raymond Barre and Jean Baptiste Marie Ernest Barre, our

page_text: IN
executors, administrators, and assigns, or such others as we, the said Jean
Baptiste Henri Honoré Raymond Barre and Jean Baptiste Marie Ernest
Barre, our 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 "IMPROVEMENTS
CUTTING OUT OR ENGRAVING METALS AND THEIR ALLOYS," upon the condition
(amongst others) that we, the said Jean Baptiste Henri Honoré Raymond
Barre and Jean Baptiste Marie Ernest Barre, 'our executors or administrators,
by an instrument in writing under our, or one of our or their or one of their
hands and seals, 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.
NOW KNOW YE, that we, the said Jean Baptiste Henri Honoré Raymond
Barre and Jean Baptiste Marie Ernest Barre, do herebydeclare the nature of
our said Invention, and in what mauner the same is to be performed, to be
particularly described and ascertained in and by the following statement, in
writing, that is to say :-
Our Invention relates to the cutting out, engraving, or perforating of
metals and their alloys by a chemical process, and consists chiefly in covering
(by the aid of printing) the parts to be left intact with a fatty or resinous
body, impenetrable to nitric acid, and leaving bare the parts which are
desired to be acted upon by the acid.
For example-Suppose that we wish to cut out a design on a plate of
copper, we first draw the design on a lithographic stone, and then ink the
same with a suitable mordant or adhesive medium, which may be composed
as follows:-One half part of printer's mordant, and one half part of copal
oil, varnish, colored with black printer's ink. We then take an impression
on paper, and by the aid of a lithographic press or other pressure we transfer
the same on to the copper-plate which we wish to engrave, and remove the
paper by slightly wetting the same, when the design will be found transferred
to the copper plate. The design having been thus produced on the plate in
the mordant or adhesive medium, is to be powdered with a resinous or fatty
substance impenetrable to nitric acid, which may be composed of two-thirds
of a resinous substance and one-third wax melted together and pulverized.
The plate is then heated and repowdered with resin only, and this operation

page_text: is repeated until a sufficient coating has been produced to resist the action of
the acid perfectly for a lengthened period. The plate is then to be submitted
to the action of nitric acid,which will attack and dissolve the uncovered paris,
and thus bite in or engrave the design, and if allowed to remain a sufficient
length of time the design will be cut out or perforated entirely through the plate.
The method of carrying our Invention into practical effect will be readily
understood froin the following detailed description thereof,-
In the first place, we cause a design to be drawn on a lithographic.stone;
the parts
which we wish to have hollow on our metallic plate being left
white on the stone, and those on the contrary which we wish to have in
relief being drawn in black.
When the design has been "bitten in" on the stone,as ordinarily practised
by lithographers, we wash the same with volatile oil, in order to remove all
the ink therefrom; we then damp the stone with a sponge, and ink it with
a particular ink, of which the following is the composition:-One-half
strong printer's mordant, one-half copal oil varnish. To this composition.we
add about one-tenth part of ordinary black printer's iuk, iu.order.to blacken
it; the whole ought to be well mixed. When the stone is sufficiently inked,
we take a proof on unsized paper; we then place our metallic plate (which
we have taken care to clean perfectly in order to free it entirely from any
foreign matter and that the surface may be very smooth) on a marble slab
resting on the lithographic press; we place the proof over it, the design in
contact with the metal, and after having lowered the tympan we submit it
to a heavy pressure. The tympan being lifted, we turn the metallic plate
over and give a second pressure. This second pressure effected we withdraw
the plate from the press and separate the design from it without damping.
It is evident, that by the double transferring of the design from the litho-
graphic stone on to the paper, and from the paper on to the metallic plate,the
latter is imprinted with the design unreversed, or in the same manner as itwas
originally traced on the stone. The desigu being thus printed on the metallic
plate with the ink of which we have above given the composition, we powder
it over with a substance of which the following are the elements:-tour-fifth
parts of a resinous substance, one-fifth part of wax,ste arine, or other similar
substance. This mixture is melted by heat, and when it is cold we grind it
on a glass slab by means of a muller, and then sift it. When the plate is
powdered therewith it must be dusted carefully with a badger brush, in
order to remove the powder which may.be upon those parts not covered with
ink. In this state we heat the plate in a stove heated by water or steam,
until the substance which covers the design adheres perfectly to the metal.

page_text: When it is desired only to obtain very light and fine engraving, the
metallic plate is then submitted to the acid without further powdering. But
if, on the contrary, deep engraving is required, the plate must be withdrawn
from the stove, and whilst it is still warm it is to be powdered over with a
resinous substance only. It is then cleaned or dusted as above described, and
this powdering is to be repeated two or three times according to the depth to
which the engraving is desired. The plate must be heated after each pow-
dering, in order that the resinous substance may adhere perfectly to the
metal. When the plate is thus prepared, it is to be smeared on all sides,
except where the design is, with resin and suet nixed and melted together.
It is then dried and placed dry in a porcelain vessel filled with acid, which is
placed under a flue to carry off the vapour.
In treating a plate of copper it must be placed in a porcelain vessel filled
with nitric acid, indicating from ten to fourteen degrees.on the acidometer,
according as it may be desired to produce deep or fine lines in the engraving.
To this bath of nitric acid some nitrate of copper must be added, and the
whole is previously placed in bottles in a sand.bath, and only withdrawn when
it it has attained a temperature of about twenty to twenty-five degrees centi-
grade. When the plate is in its bath of acid the progress of the engraving
which is developed by the power of the acid must be attentively watched.
When the plate is engraved to the required degree it must be washed in a
bath of potash, and is then ready for the market.
If we desire that the design should be reproduced on the metallic plate
in relief instead of being sunk, we trace the subject in black on the plate,
and it is consequently the design which, in the bath, is protected from the
acid; and on the contrary, all that which is not part of the design is attacked
by the acid. With this exception we proceed in all points in the same
manner as in the former case.
For engraving convex or concave objects, in order to transfer the design
from the proof, we employ a small roller to press the paper against the plate,
and with this exception we proceed as above described.
If we have a salver of goldsmith's work to engrave, we replace the ordinary
leather tyinpan of the lithographic press by a smooth cardboard well greased,
which fits in the salver on which it is desired to transfer the design. Apart
from this modification, we operate for the remainder of the process in the
same manner as described in the preceding cases.
If, however, we wish that our designs in relief should be shaded by lines
less deep, we operate as follows:-Suppose that our design in relief repre-
sents a landscape in.which are placed some animals; we trace the design.on

page_text: a lithographic stone in such a manner that those parts shall be white which
we wish to obtain less deep, and all the rest of the stone is black. We take a
proof of this design on paper similar to that described with reference to the
preceding operations, that is to say, unsized, but with this sole difference,
that it is rolled. This proof is taken by the same means and with the same
precautions as the former, of which we have spoken, and it is transferred on
to a plate of metal, which undergoes the successive operations described above.
We then submit it to the acid, which gives us the design of the shading
engraved similar to that which the lithographic stone bears. We then clean
it as above, in order that it may be deprived of fatty substances and oxide.
and the following is the supplementary and special operation to which it must
be submitted in order that the engraving may be completely finished:-We
retrace the same design on a second lithographic stone, but on which the
animals, for example, are in outline only, without any shading, and so placed
that when the transfer thereof is made by means of the proof, they shal]
cover over all the lines of shading produced by the first part of the engraving
above named. To obtain this result of exaxt super-position, it is indispens-
able to fix register points on the two lithographic stones, on the two designs,
and on the metallic plate.
We take a proof of this second part of the design by the same means as
before, and we transfer it on to the plate of metal (taking care to "register"
correctly, as above named) on which the lines for the shading are already
engraved. We then powder over and heat this plate as often as may be
necessary to obtain the lines of the engraving of the required strength, and
submit it to the acids, by which we allow it to be acted on deeply, so that
it may present when the operation is finished shading lines of less depth
according as desired.
Hitherto we have only spoken of lithographic impressions reproduced by
engraving, but we can also by the same process make use of impressions from
copper-plate to produce our designs. When we desire to perforate or cut
through the metallic plates, we proceed in precisely the same manner as for
engraving them, only we leave the metal in contact with the acid until it is
pierced or perforated completely through the plate. If the plates to be
perforated are intended also to be engraved, we operate as above indicated for
the engraving of the lines of shading on the animals. In this s case, therefore,
the first operation consists in engraving all the parts which we do not wish to
be perforated, and the second consists in transferring on to the said plate a
design which covers with ink all the engraved parts, and which leaves
uncovered all those which we desire to cut out or perforate.

page_text: By this process of engraving and perforating metals, of which we have given
all the details. we decorate gold and silver work and jewellery, whether real
or imitative, seals, book markers, and other plates for marking ciphers,
armorial bearings, and other designs. The objects engraved or cut out by this
system may attached by cementing, soldering, nailing, or screwing according
as they may be intended for the ornamentation of furniture of all kinds aud
dimensions, liqueur cases, fans, blotting cases, bindings for books, and so ou;
or for the ornamenting of apartments, doors, carriages, clocks, brushes, work-
boxes, and other objects, in short, to all artistic or fancy articles. These
objects are also capable of being covered with enamel or other enrichment
which permits of their employment for the ornamentation of articles of great
value. The objects cut out or perforated by this process can be inlaid by
hydraulic or other pressure, either in wood, papier maché, tortoiseshell, or
other material, whether plastic or otherwise.
Having now described the nature and object of our said Invention for "lin-
provements in Cutting out or Engraving Metals and their Alloys," together
with the manner of carrying the same into practical effect, we would
remark, in conclusion, that we claim as our Iuvention the system ofengraving,
cutting out, or perforating metals or alloys by means of the process above
described, and especially the three operations of transferring the printed
design on to the metal or alloy, powdering the same with a resinous and
fatty substance, and biting away the uncovered portions by means of acid.
In witness whereof, we, the said Jean Baptiste Henri Honoré Raymond
Barre and Jean Baptiste Marie Ernest Barre have hereunto set our
hands and soals, the Twenty-seventh day of February, in the year of
our Lord One thousand eight hundred and sixty.
J. B. H. H. RAYMOND BARRE. (L.S.)
J. B. M. ERNEST BARRE.
(L.S.)