IMPROVEMENTS PHOTOGRAPHY;
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY FOX TALBOT, of Lacock Abbey, in the County of Wilts, Esquire, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the First day of June, in the sixth year of Her reign, did, for Herself,
Her heirs and successors, give and grant unto me, the said William Henry
Fox Talbot, Her especial licence, full power, sole privilege and authority, that
I, the said William Henry Fox Talbot, my exors, admors, and assigns, or
such others as I, the said William Henry Fox Talbot, my exors, admors, or
assigns, should at any time agree with, and no others, from time to time and
at all times 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 "IMPROVEMENTS PHOTOGRAPHY;" in
which said Letters Patent is contained a proviso that I, the said William
Henry Fox Talbot, shall 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 Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
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
William Henry Fox Talbot, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, are particu-

page_text: larly described and ascertamed mand by the Tonowing description ther
that is to say:-
The first part of my Invention is as follows:-Since the yellowish tint of
some calotype pictures impedes the process of taking copies from them, in
order to remedy this defect I plunge the calotype picture into a hot bath of
hyposulphite of soda (or any other soluble hyposulphite). dissolved in about
ten times its weight of water.. This solution should be heated to nearly the
boiling point. The picture should remain in it about ten minutes. It is then
removed, washed, and dried. By this process the picture is rendered more
transparent, and its lights become whiter. It is also rendered exceedingly
permanent. After this process I sometimes wax the picture, by causing
melted wax to penetrate into the pores of the paper, the object of which is to
give increased transparency. This boiling process is applicable not only to
calotypes but also ie the other kinds of photographic papers which are
prepared with solutions of silver.
With respect to this part of my Invention, I claim the using hot or boiling
solutions of the hyposulphites. in order to give increased whiteness to calotype
and other photographic pictures, and at the same time make them more per-
manent; and I also claim the process of waxing a calotype picture, but only
in case the said picture has been previously whitened or rendered more trans-
parent by plunging it in a hyposulphite solution, or otherwise.
The second part of my Invention is as follows:-During the process of
taking a calotype picture with the camera, I place a warm plate of iron
behind the paper holder to communicate warmth to the prepared paper.
This makes it more sensitive, and, consequently, the picture is obtained more
rapidly.
With respect to this part of my Invention, I claim the process of warming
the paper during the formation of the picture.
The third part of my Invention is as follows:-I take a sheet of iodized
paper and wash it over with a saturated solution of gallic acid in water, and
then dry it. Paper, so prepared, I call io-gallic paper. It will remain good
a considerable time if kept in a press or portfolio. When wanted for use I
wash it with a solution of nitrate of silver, which renders it sensitive to light,
and fit to be used in the camera. This process differs from the calotype
process, formerly described by me, in not using the nitrate of silver and gallic
acid in conjunction. I find it is advantageous to use them separately on many
occasions, because it removes the great inconvenience arising from the speedy
decomposition of gallo-nitrate of silver.
With respect to this part of my Invention, I claim the preparation and use of
the io-gallic paper, as above described.

page_text: The fourth part of my Invention is as follows:- take a sheet of iodized
paper and wash it with a mixture of twenty parts gallic acid added to only one
part of nitrate of silver (the solutions being of the strength usually employed
I find that paper so prepared can easily be dried at a
in the calotype process.
gentle fire, without being spoiled thereby, and that if kept in a press it remains
good for a considerable time. It is sensitive to light, although less so than the
calotype paper prepared in the ordinary way, that is, with equal proportions of
gallic acid and nitrate of silver. But since there is some difficulty in making
the ordinary calotype paper quite dry without spoiling it more or less, therefore
I prefer to use it moist, and when I require dry paper I employ the kind
here described. But I do not confine myself to the proportion named of
twenty to one; it is obvious that this admits of some variation according
to circumstances. This paper is as convenient to use in a copying frame as
the ordinary photographic drawing paper, it being used quite dry, and it has
the advantage of being much more sensitive.
With respect to this part of my Invention, I claim the employing iodized
paper excited or rendered sensitive by a liquid containing only a small
proportion of nitrate of silver, and subsequently dried, so as to retain its
sensitive state.
The fifth part of my Invention is as follows:-I take a copy or reversed
impression of a photographic picture in the usual way, but with this difference,
that I let it remain in the light twice the usual or necessary time, in conse-
quence of which it comes out with its shadows too black, and with its lights
not sufficiently white to give a pleasant effect. 1 then wash it, and then
plunge it into a bath of iodide of potassium (of the strength of five hundred
grains to a pint of water) for one or two minutes, which makes the picture
brighter, and its lights assume a pale yellow tint. This effect may be
increased, if that is thought necessary, by afterwards exposing the picture to
the light. The picture is then washed, and then plunged into hot hyposulphite
of soda, as before described in the first part of this Specification, until the pale
yellow tint abovo mentioned is discharged, and the lights remains of a white
color. This latter process is advisable in order to ensure the permanency of
the picture, which is liable otherwise, in the course of some months, to become
more or less obliterated by a slow chemical action. The pictures, thus
finished, have a pleasing and peculiar effect of light and shade, not easily
attainable otherwise.
With respect to this part of my Invention, what I claim as new is the
producing a change, by means of iodide of potassium, in the relative intensity
of the lights and shades of a photographic copy subsequently to its first

page_text: formation, and the giving permanency by a xing process to the picture so
changed.
The sixth part of my Invention is as follows:-I take any photographic
picture made on paper, and wax it, as before described, to make it more
transparent. I then fasten a sheet of white paper behind it. By this means
I obtain pictures which have more softness than usual, and have a very
pleasing artistical. effect. I sometimes place coloured paper instead of white
paper behind the waxed picture, and by that means obtain various beautiful
tones of color.
The seventh part of my Invention is as follows:-I take an already
completely daguerrotype or calotype portrait, or other small photographic
picture, whose details are minute, and I throw, by means of lenses, a magni-
fied image thereof on a sheet of calotype sensitive paper, so as to impress the
paper with the magnified image, which, however, will be negative or reversed.
From this negative image I obtain positive copies in the usual manner. The
advantage of this method consists in the economy of the sitter's time. To
obtain such large portraits by a single process would require the sitter to sit
for his portrait without moving in the least during a space of time inconveniently
long. But by dividing the photographic action into two parts, as above
described, this inconvenience is removed.
With respect to this part of my Invention, I claim the obtaining enlarged
portraits and pictures by a double photographic process, as above described.
The eighth part of my Invention is a kind of photographic printing. Some
pages of letterpress are taken, printed on one side only. These pages are
waxed, if thought necessary..
The letters are then cut out separately, and
sorted after their kinds, and placed in separate cases for convenience of use.
In order to compose a new page, a sheet of white paper is taken, and ruled
with straight lines. The words are then formed by cementing the separate
letters in their proper order along the lines ruled upon the paper. This is
not difficult, because the letters are placed in their natural position, and not
reversed. The rest of the process is photographic. The page being completed
and ready, a negative photographic copy is taken from it, having white letters
on a black ground. This is then fixed, and then the requisite number of
copies are taken from it, which will be positive ones, videlicet, conformable to
the original, and if the process be skilfully conducted, the result will be a
resemblance to ordinary printing. Another method (which requires the use of
a camera obscura) is to employ larger letters, painted on rectangular pieces of
wood colored white. These are arranged in lines on a tablet or board, by
slipping them into grooves, which keep them steady and upright, thus forming

page_text: a page on an enlarged scale. This page is then placed before a camera
obscura, and a reduced image of it, of the size desired, is thrown upon the
sensitive paper. The adjustments, however, ought to be kept invariable,
less the consecutive pages should vary from one another in the size of
the type.
With respect to this part of my Invention, I claim the application of photo-
graphy to printing by arranging moveable letters or figures so as to form
pages, and making photographic images thereof.
The ninth part of my Invention respects what may be termed photographic
publication. Whenever a large number of nearly uniform or closely resem-
bling photographic copies are obtained from the same original it is evident
that these copies are susceptible of being published as books and engravings
are. To do this in a satisfactory manner it is evidently requisite, first. that
the copies should be similar to each other as nearly as can be; secondly, that
they should have the quality of permanency; thirdly, that they should be of a
tint agreeable to the eye. The objects most suitable for such photographic
publication are prints, engravings, drawings, letterpress, maps, photographs,
music, and similar productions. In order to accomplish this purpose I
employ a certain system of operations combined together, which I shall
proceed to describe in detail. I take writing paper, of a good quality, destitute
of water mark, and dip it into a salt water bath containing three or four ounces
of salt dissolved in a gallon of water: it is then wiped and dried. I then take a
solution of one hundred grains nitrate silver dissolved in two ounces of distilled
water, and add to it just enough animonia to form a precipitate and re-dissolve
the same, leaving the solution clear. With this solution I wash the salted paper
above described, and then dry it.. Such paper may be preserved in a press, but
should be used within two or three days. This paper may be called copying
paper. It is used to obtain a negative or reversed copy of any print, map,
photograph, drawing, or similar original object. For this purpose it is placed
in contact with such original in a copying frame consisting essentially of a
front glass and a back board, and a screw to increase the contact of the pre-
pared paper with the original. The frame is then placed in the daylight until
the negative copy is effected. This negative copy is then washed with warm
water, and then placed in a solution of hyposulphite of soda dissolved in ten
times its weight of water; it remains there two or three minutes; it is then
plunged into two or three baths of warm water consecutively, in order to
remove all that is soluble in water; it is then dried, and may be waxed, if
thought proper, for greater transparency. Such is the manner in which a
good negative copy is obtained from such original subjects as are upon paper,

page_text: such as prints and maps and others already enumerated.
A good negative
impression of distant objects is obtained with a camera upon calotype paper.
Such calotype picture may then be cleaned by boiling in hyposulphite of
soda, and also waxed, if thought necessary, as I have already 'described in the
first part of the Specification. The rest of the process is the same for both
papers; namely, for the negative on copying paper. and for the negative on
calotype paper. I shall therefore class them together, and designate either of
them by the term negative. The negative being prepared, it is now required
to obtain from it the desired number of positive copies. For this purpose the
negative is placed in contact with a second sheet of copying paper in the
copying frame, and the result of this process is a positive copy. The other
positive copies are similarly obtained; they are then fixed with hyposulphite of
soda, in the same way as the negative copy was. But this latter process is not
without difficulty, for I have found formerly that copies apparently well fixed
began to suffer a change after a month or two, and ultimately became spoiled,
not owing to the action of light, from which they were preserved, but owing to
a slow internal chemical action. In order to prevent this and to render the
use of the hyposulphite secure, I give the two following directions to be carefully
attended to; first, that the hyposulphite used for fixing the copies should be
quite free from sulphurous acid, with which it is often contaminated when sold
by chemists; secondly, that the copies, before they are fixed, and also after-
wards, should be dipped in two or three warm water baths consecutively, to
remove every trace of soluble matter from them. By using both these precau-
tions, I find the copies are permanent. And with respect to the negative
copies, I find that dark specks or irregular opacities in the interior of the
paper (which if it exists is a ruinous defect) may thus be almost wholly
prevented.
With respect to this part of my Invention, I do not here claim these
several processes as new. But what I claim as new is, the system or combina-
tion of these several processes into one, whereby a new and useful result or
branch of manufacture is produced, namely, the multiplication of very per-
manent and perfect photographic copies of the positive kind. And which
system consists essentially of four parts, videlicet: (1) the formation of the
negative copy; (2) its fixation, so as to have the requisite transparency and
be free from irregular opaque specks in the interior of the paper, and also so
as to endure without change great subsequent exposure to the light; (3) the
formation of the positive copy from the negative copy; (4) 'its permanent
fixation.
Note, the terms "calotype paper" and "iodized paper," which occur in

page_text: RICHARDS.
this Specification, have been explained in the Specification of my former
Patent for Photography, bearing date the Eighth day of February, One thou-
sand eight hundred and forty-one. And in the present Specification a general
reference is had to what has been explained and made known in the
former one.
In witness whereof, I, the said William Henry Fox Talbot. have here-
unto set my hand and seal, this Twenty-eighth day of November, in
the year of our Lord One thousand eight hundred and forty-three.
W. H. F. TALBOT. (L.S.)
AND BE IT REMEMBERED, that on the Twenty-eighth day of No-
vember, in the year of our Lord 1843. the aforesaid William Henry Fox
Talbot came before our said Lady the Queen in Her Chancery, and
acknowledged the Specification aforesaid, and all and every thing therein;
contained and specified, in form above written. And also the Specification
aforesaid was stamped according to the tenor of the Statute made for that
purpose.
Enrolled the First day of December, in the year of our Lord One thou-