AN IMPROVED MODE OF PRINTING CERTAIN COLOURS ON CALICO AND OTHER FABRICS
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENNET
WOODCROFT, late of Ardwich, in the Parish of Manchester, in the County of.
Lancaster, but now of Mumps, in the Township of Oldham, in the same.
County, Gentleman, send greeting.
WHEREAS His late most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-fourth day of December, in the seventh year of
His reign, did, for Himself, His heirs and successors, give and grant unto
me, the said Bennet Woodcroft, my exors, admors, and assigns, His especial:
licence, full power, sole privilege and authority, that I, the said Bennet
Woodcroft, my exors, admors, and assigns, and every of them, by myself and
themselves, or by my and their deputy or deputies, servants or agents, or such
others as I, the said Bennet Woodcroft, my exors, admors, or assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter, during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within that part of His
Majesty's United Kingdom of Great Britain and Ireland called England, His
Dominion of Wales, and the Town of Berwick-upon-Tweed, my Invention
of "AN IMPROVED MODE OF PRINTING CERTAIN COLOURS ON CALICO AND OTHER
FABRICS;" in which said Letters Patent there is contained a proviso obliging
me, the said Bennet Woodcroft, particularly to described and ascertain the
nature of my said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under my hand and seal, and to cause the
same to be enrolled in His Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said Letters.

page_text: Patent, (as in and by the same, reference being thereunto had, will more
fully and at large appear).
NOW KNOW YE, that in compliance with the said proviso, I, the said
Bennet Woodcroft, do hereby declare the nature of my said Invention to
consist in printing calico and other fabrics, when indigo is used to produce a
blue colour, or combined with other materials to produce other colours, in an
artificial atmosphere deprived of or devoid of free oxygen, and subsequently
allowing the indigo to imbibe the oxygen necessary for producing and fixing
the said colours by exposure to the atmospheric air, in order that the indigo
may by certain mechanical means be applied in that soluble and deoxydized
state best adapted for penetrating the substance of the fibres of the said
calico and other fabrics with uniformity, and afterwards exhibit the colour
required and become fixed by oxygenation. By which improved mode of
printing these colours I am enabled to give to the said colours so printed
upon such calico and other fabrics as aforesaid a more even or uniform
appearance than by any of the modes now or heretofore adopted; and whereby
also I am enabled to avoid the known difficulties arising to the calico printer
from the natural and rapid affinity of indigo for oxygen. And in further
compliance with the said proviso, I, the said Bennet Woodcroft, do hereby
describe the manner in which my said improved mode is or may be carried
into effect, by the following statement thereof, reference being had to
the Drawing annexed, and to the figures and letters marked thereon, that

page_text: which passes through a stuffing box fixed in the side of the chamber, as scen
on an enlarged scale at O, Figure 2, and the shaft is thrown in and out of
gear by the rod T, Figure 2, which passes through another stuffing box in the
side of the chamber. C, C (in Figure 1), represent a partition which
separates the chamber A, A, A, A, into two parts, videlicet, one where the
printing machine B is, the other where the stove or drying portion of the
apparatus is placed, and into which the calico or other fabric passes (through
the partition C, C), for the purpose of being dried after being printed.
D, D, D, D, D, are the flues by which the drying is effected. E is an
exhausting pump or cylinder with a solid piston, which is worked by adequate
motive power. This pump draws the air from the chamber A, A, A, A, through
the pipe e, e, and forces it forward by means of the pipes f. f, through the
vessels F, F, successively, and through the pipe H, H, H, again into the
chamber A, A, A, A. These vessels F, F, are of the same construction as the
liquid purifiers used in modern gasworks. The vessels F, F, contain a
solution of sulphuret of lime, which has a strong affinity for oxygen, of which
it deprives the air when mechanically forced through it. When the air in the
chamber has been passed through the solution last mentioned until all the
oxygen has been thereby absorbed, nothing but nitrogen will remain. When
a quantity of oxygen has been abstracted from the air in the chamber, a
partial vacuum is formed therein, and the pressure of the external atmospheric
air acting upon the water in the tank or water lute I, I, depresses the water
in the external portion of that tank or water lute so low that fresh atmospheric
air is admitted into the chamber. This process continues until all (or what
practically may be called all) the oxygen in the chamber has been abstracted.
This tank or water lute I, I, serves the purposes of admitting air into the
chamber when a partial vacuum is formed in the interior thereof, and of
separating the internal artificial atmosphere from the external air; it is also
the entrance, as before mentioned, by which the operatives who are to work
in the interior go in and out of the chamber. The air in the inside of the
chamber will be increased in bulk by means of the heat generated in the
drying process; therefore, at the opposite end of the chamber A, A, A, A, is
placed an ordinary gas holder, with its usual apparatus (which gas holder and
apparatus are indicated by X, X, X, X, X, X), for the purpose of receiving
air out of the chamber as the bulk of air increases therein, and allowing air to
return into the chamber when the temperature of the air therein is reduced, so
that thereby an equilibrium of pressure is, as nearly as may be, kept up inside
and outside the chamber. The operatives who are to work in the chamber
must be provided with dresses perfectly waterproof and impervious to air, and

page_text: to be so formed and adjusted as to
respire therein the external air only.
which I use) will be found sufficient for the purpose-It is made of prepared
cloth of the kind known by the name of Macintosh's waterproof or india-
rubber cloth. The dress which is shewn at Figure 4 consists of two parts;
the upper part resembles a jacket with a hood or head piece attached to the
neck of the jacket, in order to receive the head of the workman or operative..
This jacket has no other opening than at the waist and at the terminations of
the sleeves, and is impervious to water and air in all other places. In the
inside of the lowest part or waist of the jacket a circular and even belt or ring
of wood is fastened, which is about three inches broad and half an inch
in thickness. The lower part of the dress is in the form of a pair of trowsers,
terminating like boots, and without any opening except at the waist. The
waistband of the trowsers is so wide that it admits of its being drawn over the
wooden ring or belt of the jacket, round which it is so tightly bound by two
brass clips or hoops provided with tightening screws as to become water
and air tight at that junction. The wrists of the sleeves of the jacket are
so closely pressed to the wrists of the operative by india-rubber bracelets
as to prevent the entrance of water into the jacket or the entrance or escape
of air into it or out of it. The hood or head piece is provided in front with
large glasses to look through, and the junction of which with the hood or
head piece must also be water and air tight. The hood also has two elastic
tubes which are united therewith near the mouth, through one of which the
external atmospheric air is constantly forced by means of bellows or other
adequate apparatus or instruments (but I have used bellows), and through the
other of which it passes out again. These tubes, which form part of the
dress, extend from the operative through the tank or water lute I, I, to the
external atmosphere, where oue of them is attached to the bellows or other
forcing apparatus. The calico and other fabrics to be printed may be taken
in and passed out of the chamber in a dry state through a trough or lute of
mercury, as exhibibited in section Figure 3, where A, A, represents the
perpendicular side of the chamber, and 9, 9, the surface of the mercury
through which the goods are passed under the roller r. Goods, implements,
and other materials may also be passed in and out of the chamber in a dry
state through the tank or water lute I, I, when previously enclosed in a close
vessel or wrapper formed of caoutchouc or india-rubber cloth, or some other
suitable material impervious to water and air, and which should be so used
as to convey as little as may be of atmospheric air into the chamber.
admit and enable them to breathe and
The following (being the sort of dress
Now, whereas I do not claim as my Invention either the printing machine

page_text: or the particular construction or material of the chamber or apparatus which
I have mentioned, nor the particular construction or material of the dress
to be used by the said operatives; but whereas I do claim as my Invention,
the enclosing calico or other fabrics intended to be printed, along with the
printing apparatus, whatever it may be, and the material to be printed upon
them, in a chamber, case, or compartment, filled with an artificial atmosphere
deprived of or devoid of free oxygen, such as atmospheric air deprived of its
oxygen, as herein-before described, or any other suitable artificial atmosphere,
and there printing the said calico and other fabrics with a solution of
deoxydized indigo, when required to produce a blue colour, or with a solution
of deoxydized indigo and such other suitable materials as are usually used
in combination with indigo, when required to produce other colours, and
subsequently exposing the said calico and other fabrics so printed as aforesaid
to the action of the atmospheric air, in order to imbibe the necessary
quantity of oxygen therefrom to produce and fix the colours required. And
such my Invention being, to the best of my knowledge and belief, entirely
new, and never before used in that said part of His said late Majesty's United
Kingdom of Great Britain and Ireland called England, I do hereby declare
this to be my Specification of the said Invention, and that I do believe the
said Specification complies in all respects fully, and without reserve
disguise, with the proviso in the said Letters Patent contained; wherefore
I do hereby claim to maintain exclusive right and privilege to my said
Invention.
In witness whereof, I, the said Bennet Woodcroft, have hereunto set
my hand and seal, the Twenty-fourth day of June, in the year of our
Lord One thousand eight hundred and thirty-seven.