IMPROVEMENTS IN PHOTOGRAPHIC APPARATUS
Year: 1862

page_text: LETTERS PATENT to Alexander Mann, of Tottenham, in the County
of Middlesex, for the Invention of "IMPROVEMENTS IN PHOTOGRAPHIC
APPARATUS."
PROVISIONAL SPECIFICATION left by the said Alexauder Mann at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
April 1862.
I, ALEXANDER MANN, of Tottenham, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PHOTOGRAPHIC
APPARATUS," to be as follows:-
This Invention consists, firstly, in improved apparatus forming a new photo-
graphic camera shutter for uncovering and covering the lenses more conveniently
and admitting the requisite amount of light in a much shorter time than by
any existing arrangement. It is therefore especially adapted for the production
of the (so-called) instantaneous pictures. It possesses these advantages by
reason of the covering consisting of two pieces or parts, the edges of which
overlap each other in front of the centre of the lens so as to exclude the light,
and the exposure is given by their separation in front of the centre, and their
motion in opposite directions towards the edges of the lens, which is thus
completely uncovered by the time each limb of the shutter has moved through
a distance equal to half the diameter of the lens. The lens is again covered

page_text: by the shutters moving back from the edges to the centre. The shutter
consists of two plates of wood or metal, or opaque membrane or other suitable
material; there are rectangular openings in each, of a diameter at least equal to
that of the lens, when these are placed so as exactly to coincide, the openings
coincide also and are in front of the lens, but when one plate is drawn to the
left and the other to the right, the opaque portions of the plate meet in front of
the lens and are held in this position by a small spring against the action of elastic
bands, which are attached to the slides or plates, and tend to move them in
the contrary direction. On releasing this spring the elastic bands draw the
slides across the lens and thus uncover it, and passing still onward they at
last sbut it up again by the other ends coming in front of it. The plates are
so arranged as to slide accurately in a frame, and are connected by a cord
passing over a smooth surface or a pulley, so that one slide cannot move
without the other moving simultaneously in the opposite direction. These
plates move in a plane at right angles to the axes of the lenses, and may be
placed immediately in front of the lenses or behind them, or in case of two
combinations in the tube, between the lenses. The plates may move in a
vertical direction, or other direction if required, and they may be adapted to any
number of lenses by making the requisite number of apértures in the plates.
The second part of the Invention relates to a method of changing the
direction of the lens and picture without moving the apparatus, whereby an
extended landscape may be brought within the scope of the instrument. This
is accomplished by arranging a centre or turntable movement under the front
part of the instrument upon which the lens is turned to the right or left. A
connecting rod extends back to the picture and moves it accordingly, its
action being aided by a semicircular train and rollers, the whole being actuated
by an adjusting screw and toothed or other gearing.
The third part relates to a method of affording a longer period of time for
the action of light on the foreground of the picture than on the sky or
upper part; this is accomplished by a curtain or blind situated in the interior
of the camera and near the picture, and capable of being drawn gradually
downwards by a cord or spring so as to expose the picture accordingly.
The fourth part relates to improved apparatus for finishing photographs on
paper, and consists in heating the sliding table on which the picture rests by
means of gas in such a way that the heat shall rise to any given temperature,
and there remain stationary for any length of time, thus affording the advantages
of hot-pressing with perfect safety from charring the picture. The sliding
table is to be made hollow and the gas is to be conveyed to it by a flexible
tube, and made to issue from small openings in the lower side.
In the upper

page_text: side of this table a quantity of mercury is lodged, which expands with the
increased temperature, and moves a piston in a tubo actuating by means of a
lever the stop cock of the supply pipe, and curtails the supply of gas,
and vice versa.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alexander Mann in the Great Seal Patent Office on the
3rd October 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MANN, of Tottenham, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of April, in the year of our Lord One
thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alexander Mann, Her special licence that I, the said Alexander Manu,
my executors, administrators, and assigns, or such others as I, the said Alexander
Mann, 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 "IMPROVEMENTS IN PHOTOGRAPHIC
APPARATUS," upon the condition (amongst others) that I, the said Alexander
Mann, 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 Alexander Mann, 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:-
My Invention consists of certain improvements in photographic apparatus,
being contrivances for obtaining an instantaneous exposure and closing of the
lens, and for enabling the landscape photographer to secure impressions of
clouds or any desired atmospheric effect along with the darkest foreground on
the same plate. In ordinary circuinstances a much longer exposure is required

page_text: for the foreground of a landscape than for the bright clouds and sky, so that
they cannot be both obtained at the same time. The methods herein described
will admit of a different period of exposure being given to each by cutting off
all the light from the sky during the greater part of the time the foreground
is being exposed.
My Invention consists, firstly, of an improved apparatus, forming a new
photographic camera shutter, for uncovering and covering the lenses more
conveniently and admitting the requisite amount of light in a much shorter
time than by any existing arrangement. It is therefore especially adapted for
the production of the (so-called) instantaneous pictures. It possesses these
advantages by reason of the covering consisting of two pieces or parts, the
edges of which overlap each other in front of the centre of the lens so as to
exclude the light, and the exposure is given by their separation in front of the
centre and their motion in opposite directions towards the edges of the lens,
which is thus completely uncovered by the time each limb of the shutter has
moved through a distance equal to half the diameter of the lens. The lens is
again covered by the shutters moving back from the edges to the centre. The
shutter consists of two plates of wood or metal, or opaque membrane or other
suitable material; there are rectangular openings in each of a diameter at
least equal to that of the lens. When these are placed so as exactly to
coincide, the openings coincide also and are in front of the lens, but when one
plate is drawn to the left and the other to the right, the opaque portions of
the plate meet in front of the lens and are held in this position by a small
spring against the action of elastic bands which are attached to the slides or
plates and tend to move them in the contrary direction. On releasing this
spring the elastic bands draw the slide across the lens and thus uncover it,
and passing still onward they at last shut it up again by the other ends coming
in front of it. The plates are so arranged as to slide accurately in a frame,
and are connected by a cord passing over a smooth surface or a pulley, so that
one slide cannot move without the other moving simultaneously in the opposite
direction. These plates move in a plane at right angles to the axes of the
lenses, and may be placed immediately in front of the lenses or behind them,
or in case of two combinations in the tube, between the lenses. The plates
may move in a vertical or other direction, if required, and they may be
adapted to any number of lenses by making the requisite number of aper-
tures in the plates; and instead of the lenses being covered up by the plates
passing onward, as above indicated, they may be uncovered by gently pulling
a cord attached to the end of one plate, and on the requisite amount of
exposure being obtained the plates may be allowed to cover them up by a

page_text: retrograde movement induced by the action of the elastic bands. In cases
where there is not sufficient room for admitting of the plates sliding along
I substitute membranes of soft leather, which are connected together in the
same way as the plates, but clear the field of view by doubling up into the
recesses of the frame.
The first example of the application of the second part of my Invention is
when the arrangement is inside the camera in front of the sensitive plate, and
I now proceed to describe the method of operating in this instance, reference
being had to the Drawings hereto annexed, and to the Figures and letters of
reference marked thereon. For this purpose a light frame with a groove for
carrying a sheet of dark-colored paper or cardboard, &c., is fitted permanently
into the body of the camera in front of the dark slide containing the sensitive
plate, and made to turn on an axle, one end of which projects through the side
of the camera and terminates in a milled head.
Fig. 1 represents a longitudinal section, and Fig. 2, a transverse section.
When the camera is arranged for a landscape and the lenses put in focus I
dip a pointed piece of wood or a pen in a mixture of ink and honey, or any
deliquescent substance, and trace the line the horizon makes on the focussing
glass. While the ink is still wet I apply to the focussing glass a sheet of
dark colored paper of the same size, to which the inky line is thus transferred.
The upper part of the paper is then cut away by the line and the other part
slipped into the frame s, which is held in a position parallel to the sensitive
plate by the tension of a slender elastic thread, cord, or band, which connects
the lower part of the frame with the posterior end of the camera, as indicated
at a. The exposure is effected by uncovering the lenses, when the rays of
light fall with full intensity on the foreground of the picture, but are alto-
gether cut off from the sky. When the foreground has been exposed for
about the requisite time, the lenses are to be covered up, and by means of the
milled head the frame is turned down out of the way into the position indi-
cated by the, dotted lines at s¹, and an exposure is given over all the plate
sufficient for the clouds and sky. Instead of the frame being mounted on
an axle it may be simply binged on to the bottom of the camera, and a cord
attached to it and passing through the camera may be used for lowering it, as
indicated in Fig. 1 at c. One or more spring clips may be fastened on each
limb of the frame to press against the paper in the grooves so that the paper
may be slightly raised or depressed at pleasure and held in the desired position.
Instead of the line being traced with ink in the way I have mentioned, a piece
of thin white paper may be placed on the focussing glass and the horizon
traced with a pencil, then, by placing that upon the dark paper, the latter may

page_text: be cut of the desired form and size. Instead of this arrangement the light
may be cut off from the sky by a covering in front of the plate composed of a
number of small pieces of wood or metal, &c., sliding up and down, with a
sufficient amount of friction, through a channel in the bottom of the camera
and accessible from the outside.
I will now proceed to describe another contrivance for effecting the fore-
going object The apparatus consists of a small rectangular box or hood
placed upon the front of the lens tube, open in front, and the four sides are
hinged on to the back part so as to fold down upon it for the sake of porta-
bility. On the front edges of the two sides are guides, into which slides a
frame, as indicated by Fig. 3, which is a sectional elevation. This frame is
packed with a number of uniform pieces e of metal, wood, vulcanite, or other
adaptable material, so that each. piece is capable of sliding up and down with
a small amount of friction and forming in their combined state a light-proof
covering to the upper part of the front of the hood. Fig. 4 represents a hori-
zontal section of the upper part of this frame, shewing the form of these pieces
and the way in which they fit into each other so as to form a light-proof covering,
as well as the method whereby they are kept and held together by cross bars f
and clamping screws h; springs or other fastenings might of course be sub-
stituted for the clamping screws. Or these slips may be of a rectangular form
and arranged in two rows, as represented in the section, Fig. 5.
In taking a landscape with this contrivance the operator has simply to focus
his lenses, and then, while he is looking at the image on the focussing glass, to
run his finger along the top of these small slips and move them upwards or
downwards till they form such an outline that the sky is just all cut off; he
must then give the requisite exposure for the foreground, then cover the lens,
then remove this frame from the front of the hood and give a very brief
exposure over all the plate just sufficient for the sky. This contrivance also
improves the foreground of a landscape, as it cuts off a deal of light which
would otherwise enter and become diffused through the camera. As a sub-
stitute for the frame just described forming the front of the hood a sheet of
dark-colored paper or other suitable thin material e may be cut of the requisite
form and placed in guides g in front of the hood, as indicated at Figs. 6 and 7,
which are respectively longitudinal and transverse sections. These guides or
rods are furnished with small rings i sliding up and down with sufficient
friction to retain their adjusted elevation and so support at the desired height
the paper, the two ends or edges of which rest upon them. The instantaneous
shutter being made with a hood, I cause the frame above-mentioned to fit into
the front thereof, so as to form a part of the same. In other cases I construct

page_text: the hood and sliding frame in front in separate instruments, the lenses being
uncovered by any of the ordinary means.
Having now described and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, I would remark in conclusion
that I do not limit myself to the exact details herein expressed and shewn, as
the same may obviously be varied or modified in many ways without departing
from the principles upon which my Invention is based, and which are first
herein stated; but what I claim and desire to be secured to me are the
arrangements for uncovering and covering the lenses instantaneously, and the
separate methods or contrivances for shutting off the light from the sky or
clouds while the foreground of a photographic picture is exposed, substantially
in the manner herein specified and illustrated by the Drawings hereunto
annexed.
In witness whereof, I, the said Alexander Mann, have hereunto set my
hand and seal, this Twenty-ninth day of September, in the year of our
Lord One thousand eight hundred and sixty-two.
Witness,
ALEX. PRINCE,
Agent for Patents,
4, Trafalgar Square,
Charing Cross.
ALEXANDER MANN. (L.S.)

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