A NEW MODE OF ENGRAVING AND ETCHING METAL ROLLERS USED ROR PRINTING UPON WOOLLEN, COTTON, LINEN, PAPER, CLOTH, SILK, AND OTHER SUBSTANCES
Year: 1821

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LEIGH BRADBURY, of Manchester, in the County Palatine of Lancaster, Gen-
tleman, send greeting.
WHEREAS His most Excellent Majesty King George the Fourth did, by
His Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Ninth day of
January, in the first year of His reign, give and grant unto me, the said
John Leigh Bradbury, my executors, administrators, and assigns, His special
licence, full power, and sole privilege and authority, that I, the said John
Leigh Bradbury, my executors, administrators, and assigns, during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "A NEW MODE OF ENGRAVING AND ETCHING METAL ROLLERS
USED ROR PRINTING UPON WOOLLEN, COTTON, LINEN, PAPER, CLOTH, SILK, AND
OTHER SUBSTANCES;" in which said Letters Patent there is contained a proviso
obliging me, the said John Leigh Bradbury, by an instrument in writing
under my hand and seal, to cause a particular description of the nature of
my said Invention, and in what manner the same is to be performed, to be
inrolled in His Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said recited Letters Patent, as in
and by the same (relation being thereunto had) may more fully and at large
appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Leigh Bradbury, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly
described and ascertained as follows (that is to say):-
The roller should be without joint, free from blemish, and well polished.
To prepare the roller for varnishing, it must be made hot, which may be
accomplished by different methods, first, by turning it on an axle over a clear
charcoal fire; secondly, by immersing it in hot water for some time; and,
thirdly, by placing it in a close vessel into which steam may be admitted:
but I am of opinion that the second plan, namely, that of boiling water, is the
simplest and most effectual. Previous to immersing the roller in hot water,
it should be wrapped in a cloth, to prevent the sides or bottom of the boiler
from injuring the surface of the roller, and a strong cord or other means of
lifting should be passed through the inside of the roller, for the purpose of
When the water has boiled
putting it in and lifting it out of the boiler.
a few minutes the roller may be considered nearly of the same heat as the
water, and it is then hot enough for varnishing, and must be lifted out, and
a round plug of hard wood put into each end, which plugs are to rest upon
two steps, so that the roller may revolve horizontally while it is varnishing;
the cloth should then be removed as expeditiously as possible, and the surface
of the roller rubbed with a dry cloth to prevent the water from drying on the
surface in stains; it should then be removed into a room the floor, walls, and
even ceiling of which have been previously sprinkled with water, in order to
prevent the least dust from settling upon the surface of the varnish. My.
mode of varnishing rollers is accomplished in the manner following, that is to
say, by rubbing the varnish tied in silk cloth equally on from end to end,
and dabbing it evenly with wool tied up in taffeta. The varnish is what is
commonly called etching varnish, and made by me, in what I believe the
usual way, as follows:-Take four parts of asphaltum, four parts of bees' wax,
one part of black pitch, and one part of Burgundy pitch; melt the wax and
pitch in an earthenware glazed pipkin, and add to them by degrees the
asphaltum finely powdered; let the whole boil for a longer or shorter time,
according to the hardness wanted. When the roller is cold it is ready to
receive the pattern, which is to be worked or engraved upon it with a
diamond, steel, or other point, which point may be moved by hand or by
machinery, as circumstances may require, so as to pass through the varnish, as
is commonly done on flat plates. The pattern being finished, the roller is
ready for etching; my method of effecting which is by immersing the roller in
aqua-fortis and water in the manner following:-The roller must have a plug

page_text: of soft wood driven very tight into each end, and very opening sealed up with
hot pitch, or any substance resisting the aqua-fortis. The ends of the roller and
those parts not meant to be etched must be defended by turpentine or other
varnish. On the end of each plug which is not driven into the roller (which
may be in length three or four inches) a wooden disk or pully should be
placed, which must be larger in diameter than the roller, and of a sufficient
thickness to admit a grove for a cord to run in, and the roller is then ready to
be immersed into the aqua-fortis and water. The aqua-fortis, of the strength
required which practice shews, is contained in a trough formed of earthenware,
or of glass, or of wood thickly coated with pitch or varnish so as to resist the
aqua-fortis, which trough must admit the roller freely within it, and should
have a glass cock fixed in one end for the purpose of drawing off the liquid.
Over the centre of the trough, and three or four feet above it, is to be fixed a
wooden roller, about four inches in diameter, and of the full length of the
trough, to the end of which roller is attached a handle to turn it round;
suspended by a cord wound round each end of this roller is a step or iron
ring, to support the axles of another wooden roller, also about four inches in
diameter, which last-mentioned roller must revolve freely on its axles. By
turning the handle of the upper roller the lower roller suspended by the cords
can be raised or lowered. Upon each end of this suspended roller is a pully
corresponding with the, pullys on the plugs in the ends of the metal roller.
When it is in the trough, endless cords or bands pass round the pulleys of the
suspended roller and round the pulleys on the plugs of the metal roller.
The manner of using the machine is as follows:-The metal roller being
immersed in the aqua-fortis contained in the trough, it is necessary from time
to time during the operation of the aqua-fortis upon the metal to turn the
roller, in order to prevent the lower surface (which sustains the greatest
pressure of the fluid) from being more deeply eaten in or engraved than
the upper surface (which sustains less pressure).
It is also necessary
occasionally to lift the roller, out of the aqua-fortis, in order to let the air
bubbles escape, and with some patterns the roller must be lifted out in.
order to stop out parts. In order to accomplish these objects, the handle
upon the end of the upper roller is turned round to raise the roller from
the bottom of the trough. The suspended roller is then turned by the hand
which turns the metal roller attached by means of the endless cords or bands
at each end of the rollers, and this is continued until the roller is etched or
engraved of the depth required. The pulleys on the roller being larger than
the roller in diameter prevent the surface from touching the bottom of the
trough. When the roller is raised out of the trough, either for the purpose of

page_text: stopping out parts of the pattern, or when it is finished, it should be imme-
diately washed with water. as is done in the case of flat plates; in short, my
Invention for engraving and etching the whole surface of the roller is upon
the principle hitherto applied to flat plates. The apparatus for lowering the
roller into the aqua-fortis, and raising it up again, as required, and for making
it revolve while wholly or partly immersed, may be made in various other
ways besides that described, which it is not material to specify, as it is the
operation applied to rollers, and not the apparatus for effecting it, which is the
object of the Patent. It should also be noted, that though I-have directed
the roller to be wholly immersed in the aqua-fortis, as being superior to a
partial immersion, yet a partial immersion will also effect the same purpose
when the roller is made to revolve. In some cases this latter method may be
also used.
In witness whereof, I, the said John Leigh Bradbury, have hereunto
set my hand and seal, this Ninth day of July, in the year of our
Lord One thousand eight hundred and twenty one.
J. S. HARVEY.
the year above mentioned, the aforesaid John Leigh Bradbury came before
our Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained, in form above written.
And also the Specification aforesaid was stamped according to the tenor of
the Statute in that case made and provided.
Inrolled the same Ninth day of July, in the year first above written.