AN IMPROVEMENT IN DYEING CLOTH
Year: 1855

page_text: LETTERS PATENT to Thomas Richardson, of Leeds, in the County of
York, Drysalter and Manufacturing Chemist, for the Invention of "AN
IMPROVEMENT IN DYEING CLOTH."
Sealed the 3rd November 1855, and dated the 16th May 1855.
PROVISIONAL SPECIFICATION left by the said Thomas Richardson at
the Office of the Commissioners of Patents, with his Petition, on the
16th May 1855.
I, THOMAS RICHARDSON, of Leeds, in the County of York, Drysalter and
Manufacturing Chemist, do hereby declare the nature of the said Invention
for "AN IMPROVEMENT IN DYEING CLOTH" to be as follows:-
The object of this Invention is to produce a permanent black dye in woollen
cloths; for this purpose I mordant the cloths with bichromate of potash, and
then dye them in a bath composed of sulphate of indigo, and of other suitable
dyeing materials, such as logwood.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Richardson, Her special license that I, the said Thomas
Richardson, my executors, administrators, and assigns, or such others as I, the
said Thomas Richardson, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 IMPROVEMENT IN
DYEING CLOTH," upon the condition (amongst others) that I, the said Thomas
Richardson, by an instrument 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.
NOW KNOW YE, that I, the said Thomas Richardson, do hereby
declare the nature of my said 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):-
:-
The main object of this Invention is to produce a permanent black dye in
woollen cloths, and at a less cost than the best black dyes are at present
obtained. For this purpose I mordant the cloths with bichromate of potash,
and then submit them to a bath composed of sulphate of indigo and other
suitable dyeing materials. The manner in which I proceed first to preparo
the cloth, and afterwards to dye it, is as follows:-
In order to prepare, say, six ends of cloth, I pour into a vessel of the
ordinary kind used by dyers any requisite quantity of water, and add thereto
four pounds of bichromate of potash, three pounds of red argol (bitartrate of
potash), and six pounds of commercial sulphuric acid. I heat the contents of
the vessel to the boiling point, and then enter the six ends or pieces of woollen
cloth, which will average in length about twenty-four yards each. I boil these
for one hour, turning them over by means of a winch to keep them even. I
then remove the woollen pieces from the vessel, and hang them over a horse-
tree to drain away the superfluous liquor which they have taken up, after
which the ends of cloth are ready to undergo the dyeing operation.
To dye the cloth I prepare in a second vessel (similar to that used in the
first operation) the dyeing liquor. For this purpose I fill the vessel with

page_text: water, and put therein one hundred pounds of logwood, four pounds of cam-
wood or other red wood, two pounds of fustic, four pounds of the sulphate of
indigo, and three pounds of sulphuric acid in addition. This mixturo I heat
to about two hundred degrees Fahrenheit, and I then enter the six ends of
cloth, and keep the liquor to the boiling point for about one hour and twenty
minutes. During this time (which will in general suffice for completing the
dyeing operation) I turn the cloths over frequently by means of a winch to
ensure the thorough exposure of the whole body of the fabric to the dyeing
liquor. I next remove them from the dye vessel, and rinse them in a washing
machine along with a little fullers' earth. With a smaller proportion of
bichromate of potash and logwood than is given above, I find I can obtain
a blue colour resembling indigo dyed blue. I may also remark than when a
full black is required, it will be found an improvement to use a little acetate
of lead.
Having now set forth the nature of any Invention of "An Improve-
ment in Dyeing Cloth," and explained the manner of carrying the same into
effect, I wish it to be understood that under the above in part recited Letters
Patent I claim, the mode of dyeing cloth as above described, whereby I am
enabled to give permanency to the colour, and enable it to resist the usual acid
tests (which now determine the market value of the fabric), like woaded
indigo colours.
In witness whereof, I, the said Thomas Richardson, have hereunto set
my hand and seal, the Fourteenth day of November, in the year of
our Lord One thousand eight hundred and fifty-five.
THOMAS RICHARDSON. (LS.)
Signed and sealed by the said Thomas Richardson,
in the presence of
J. B. WILKINSON,
Clerk to Messrs. J. & H. Richardson & Gaunt,
Solicitors, Leeds.