AN IMPROVED METHOD OF PROVISIONAL SPECIFICATION
Year: 1857

page_text: LETTERS PATENT to John Underwood, of Gloucester Road, in the County
of Middlesex, Gentleman, for the Invention of "AN IMPROVED METHOD OF
PROVISIONAL SPECIFICATION left by the said John Underwood at the
Office of the Commissioners of Patents, with his Petition, on the
20th April 1857.
I, JOHN UNDERWOOD, of Gloucester Road, in the County of Middlesex,
Gentleman, do hereby declare the nature of the said Invention for "AN
IMPROVED METHOD OF PRINTING, AND OF PREPARING MATERIALS EMPLOYED THEREIN,"
to be as follows:-
My Invention consists in printing, writing, or otherwise marking upon
paper, parchment, or other suitable material with a solution of extract of log-
wood, or with a material or varnish soluble in water, or other like suitable
vehicle; and when with the latter, in dusting or throwing over it extract of
logwood in powder. In order to obtain impressions from matter produced
upon paper or other suitable writing material, as aforesaid, I treat the paper
upon which the impressions are to be obtained to a solution of neutral
chromate of potash or other agent, which will have a like effect in absorbing
the extract or powder of logwood, and use the paper so treated in a damp
state. Or, instead of logwood and chromate of potash, I employ other
materials which have a strong affinity for each other, and which, when acted
upon in the manner above described, throw down colored precipitates, as, for
instance, sulphate of iron and infusion of nut galls.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Underwood in the Great Seal Patent Office on the
20th October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
UNDERWOOD, of Gloucester Road, in. the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of April, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year. of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Underwood, Her special licence that I, the said John Underwood,.
my executors, administrators, and assigns, or such others as I, the said John
Underwood, my 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 "AN IMPROVED METHOD OF PRINTING,
AND OF PREPARING MATERIALS EMPLOYED THEREIN," upon the condition (amongst
others) that I, the said John Underwood, my executors or administrators, by
an instrument in writing under my, 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 I, the said John Underwood, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say):-
:
The object of my Invention is to facilitate the printing or production of
copies of printed, written, or other characters or marks which have been
impressed or otherwise produced upon the surface of paper, parchment, or
other similar material, and I effect this by preparing the substance of which
the printed, written, or other characters or marks are composed, and also the
paper, parchment, or other material upon which they are to be copied, in
such manner that when the latter, after having been moistened, is brought
in contact with the former, a chemical action shall take place, by means of
which copies of the printed; written, or other characters or marks shall be
produced upon the prepared paper, parchment, or other material.

page_text: In carrying my Invention into effect I print, write, or otherwise mark upon
paper (supposing paper to be the material used) with a solution of an extract
of logwood or with a material or varnish soluble in water, or other like
suitable vehicle; and when with the latter, I dust or throw over it extract of
logwood in powder, and I treat the paper (supposing paper to be the material
used) for this purpose also) upon which the impressions are to be obtained,
with a solution of neutral chromate of potash or other agent, which will have
a like effect by precipitating a colored material where the extract or powder
of logwood is absorbed, and use the paper so treated in a damp state, the
impression being taken in any suitable manner. I do not confine myself to
the use of logwood and chromate of potash, or to chemical agents producing
a chemical action analagous to theirs, as the chemical agents employed to
produce the desired effects may be greatly varied, and the nature of the
chemical action produced depends upon the agents employed. I sometimes,
for example, prepare the copying paper with a chemical substance which shall
produce the copy when brought in a damp state into contact with the printed,
written, or other character or marks by dissolving or partially dissolving the
substance used in producing the characters or marks, which is the case if I
preparo the copying paper with a solution of oxalic acid, and the characters or
marks with Prussian blue freshly prepared. Or, I prepare the copying paper
with a chemical substance which shall produce the copy when brought into
contact with the characters or marks by chemical precipitation, which is the
case if I preparo the copying paper with a solution of gallic acid, and the
characters or marks with a solution of sulphate of iron. Or, I prepare the
copying paper with a chemical substance which shall produce the copy when
brought into contact with the characters or marks by chemical reaction, which
is the case if I prepare the copying paper with a solution of perchloride of
iron, and the characters or marks with a solution of sulpho-cyanide of
potassium.
But while the means employed for producing the desired effects may be
varied, I prefer the following for general use:-I damp the paper, parch-
ment, or other material which I desire to copy upon with a solution of two
hundred grains of the yellow or neutral chromate of potash dissolved in one
gallon of distilled water, and either use it immediately, or dry it and sub-
sequently damp it with water as it is required for use. I then prepare the
material which I use for producing the characters or marks, and which may
be called copying ink, by simply dissolving (in a water bath) puro extract of
logwood in distilled water; or, for printing I use a varnish or other similar
material soluble in water, and dust or throw over it powdered extract of

page_text: logwood. If I desire to take twenty copies from an original, I use about six
pounds of the puro extract of logwood to a gallon of distilled water; but a
larger number of copies may be taken by dusting or throwing over the
original, before the ink has thoroughly dried, a powder composed of five parts
of powdered extract of logwood, one part of powdered gum arabic, and one
part of powdered tragacairth. When I desire to print from an original, in
producing which I have used ink prepared as before described, I proceed by
damping six sheets of paper prepared as before described, and having taken
off all superfluous moisture with good blotting paper, I place the original
upon the upper sheet and press the whole for about half a minuto in a
copying press; I then remove the original, and in its place put six other
sheets of the prepared paper in a damp state, and subject the whole to
pressure for about a quarter of an hour; I then take five other prepared sheets
in a damp state, and having laid the original upon them, press them together
for about two minutes, then replace the original by three other prepared and
damped sheets, and press the whole together for about a quarter of an hour.
The extract of logwood so acts upon the neutral chromato of potash that I
thus obtain twenty good clear fac-similes of the original matter or design.
The Invention is applicable to the production of copies of maps, charts,
plans, and other similar prints or drawings, as well as to ordinary written and
printed papers or designs.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the method of printing or obtaining copies of documents, forms;
maps, plans, designs, or any other characters or marks which may be produced
upon paper, parchment, or other similar material, by forming these charactors
or marks of a prepared ink, and bringing them in contact with prepared paper
under pressure, the ink and paper being prepared in such manner that when
the two are brought together a chemical action takes place, whereby copies of
the said characters or marks are produced, ás herein-before described.
Secondly, preparing copying ink and copying paper, in the inanner and for
the purposes herein-before described.
In witness whereof, I, the said John Underwood, have hereunto set my
hand and seal, this Twentieth day of October, in the year of our Lord
One thousand eight hundred and fifty-seven..
JOHN UNDERWOOD. (L.S.)