IMPROVEMENTS IN THE PRE- PARATION OF PAPER FOR TAKING IMPRESSIONS OF MATTER, WRITTEN OR PRINTED, IN INKS WHICH ARE PREPARED OR UNPREPARED FOR COPYING PURPOSES."
Year: 1877

page_text: LETTERS PATENT to Frederick Hawke, of St. John's Wood Park, in the County
"
of Middlesex, Gentleman, for the Invention of IMPROVEMENTS IN THE PRE-
PARATION OF PAPER FOR TAKING IMPRESSIONS OF MATTER, WRITTEN OR
PRINTED, IN INKS WHICH ARE PREPARED OR UNPREPARED FOR COPYING
PURPOSES."
led the 22nd September 1877, and dated the 17th May 1877.
PROVISIONAL SPECIFICATION left by the said Frederick Hawke at the
Office of the Commissioners of Patents on the 17th May 1877.
FREDERICK HAWKE, of St. John's Wood Park, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE PREPARATION OF PAPER FOR TAKING IM-
PRESSIONS OF MATTER, WRITTEN. OR PRINTED, IN INKS WHICH ARE PREPARED OR
UNPREPARED FOR COPYING PURPOSES."
This Invention has for its chief object to provide paper which, by the usual
practice of damping before use, as with ordinary copying papers, will readily take
impressions from written or printed matter which has been written or printed with
inks free from the impurities inseparable from specially prepared copying inks. I
thereby render it possible and advantageous to use a purer, better, and cheaper ink
for copying than can be used with ordinary copying paper, which ink being also
suitable for all other purposes, the expense, trouble, and annoyance is avoided which
results from the necessity of using two separate inks, that is to say, one kind for
copying and the other for ordinary purposes.
The paper prepared according to this Invention also produces better impressions
The said paper
from prepared copying inks than any other paper at present in use.
can be prepared inexpensively and will be economical in use.
In carrying my Invention into practice I mix with the pulp of the paper in
course of manufacture a solution consisting of oxalic or citric acid and perchloride
of iron of a sufficient strength, according to the thickness of the paper being manu-
factured, for the attainment of the objects above mentioned without the proportion
being so great as to cause any deterioration in the substance of the paper.

page_text: The proportions I propose to employ are as follows, that is to say:-For paper
weighing twelve to fifteen pounds to the ream of four hundred and eighty sheets,
with the water used in manufacturing three hundred pounds weight of pulp from
the rag engine I add about one and a half gallons of perchloride of iron, in
which is dissolved about sixteen ounces of pure crystals of oxalic acid. For paper
weighing six to seven and a half pounds to the ream of four hundred and eighty
sheets, with the water used in manufacturing three hundred pounds weight of pulp
from the rag engine I add about one and a quarter gallons of perchloride of iron, in
which is dissolved about twelve ounces of pure crystals of oxalic acid. For other
thicknesses of paper I use a corresponding strength of solution to those indicated
above, according to the weight per. ream.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Frederick Hawke in the Great Seal Patent Office on the 13th
November 1877:
65
FREDERICK 'HAWKE, of St. John's Wood Park, in the County of Middlesex,
Gentleman. IMPROVEMENTS IN THE PREPARATION OF PAPER FOR TAKING IM-
PRESSIONS OF MATTER, WRITTEN OR PRINTED, IN INKS WHICH ARE PREPARED OR
UNPREPARED FOR COPYING PURPOSES."
This Invention has for its chief object to provide paper which by the usual
practice of damping before use, as with ordinary copying papers, will readily take
impressions from written or printed matter which has been produced with ink free
from the impurities inseparable from specially prepared copying ink. I thereby.
render it possible and advantageous to use a purer, better, and cheaper ink for
copying than can be used with ordinary copying paper, which ink is also suitable
for all other purposes for which ink is used. I avoid the cost, trouble, and
arinoyance which result from the necessity of using two separate inks, that is to say,
one kind for copying and the other for ordinary purposes.
The paper prepared according to this Invention also produces better impressions
from prepared copying ink than any other paper at present in use, and will copy
documents which have been previously copied."
The essential feature of my Invention consists in the preparation of special
copying papers by mixing oxalic or citric acid and the perchloride of iron with the
pulp during the process of manufacture. Copying papers thus made can be used in
the same manner as ordinary copying papers, that is, by moistening them with
water in the usual way before taking impressions of documents.
The proportions in which the acids and the perchloride of iron are to be employed
are regulated according to the thickness of the paper required to be manu-
factured, as herein-after described, to avoid any deterioration in the substance of
the paper.
The proportions I prefer to employ are as follows, that is to say For paper
weighing twelve to fifteen pounds to the ream of four hundred and eighty sheets,
each measuring üineteen by twenty-two inches, with the water used in manu-
facturing three hundred pounds weight of pulp from the rag engine I add about one
and a half gallons of perchloride of iron calculated at Fe, Cl, and in which is
dissolved about sixteçu ounces of pure crystals of oxalic acid. For a paper weighing
six to seven and a half pounds to the ream of four hundred and eighty sheets. each

page_text: measuring nineteen by twenty-two inches, to the water used in manufacturing
three hundred pounds weight of pulp from the rag engine I add about one and a
quarter gallons of per chloride of iron calculated at Fe, Cl, and in which is
dissolved about twelve ounces of pure crystals of oxalic acid. For other thicknesses
of paper I use a corresponding strength of solution to those indicated above, according
to the weight per ream.
I use the above-named combination as the cheapest and best, but other acids, such
as citric may be employed, and I may use either the perchloride or the sulphate of
iron, with each of which and without the addition of the acids above named I have
obtained results inferior only to those given by the combination specified.
Having thus fully described my said Invention and the manner of performing the
same, I wish it understood that I claim, the preparation of special copying papers by
mixing oxalic or citric acid and the perchloride or sulphate of iron with the pulp
during the process of manufacture, as herein-before described.
In witness whereof, I, the said Frederick Hawke, have hereunto set my hand
and seal, this Twelfth day of November, in the year of our Lord One
thousand eight hundred and seventy-seven.
FREDERICK HAWKE. (L.S.)