IMPROVEMENTS IN PHOTO- GRAPHIC CAMERAS
Year: 1865

page_text: LETTERS PATENT to Victor Albert Prout, of Manor House, East Mousley,
in the County of Surrey, for the Invention of "IMPROVEMENTS IN PHOTO-
GRAPHIC CAMERAS."
Sealed the 3rd October 1865, and dated the 8th April 1865.
PROVISIONAL SPECIFICATION left by the said Victor Albert Prout
, at the Office of the Commissioners of Patents, with his Petition,
on the 8th April 1865.
I, VICTOR ALBERT PROUT, of Manor House, East Moulsey, in the County:
of Surrey, do hereby declare the nature of the said Invention for "IMPROVE.
MENTS IN PHOTOGRAPHIC CAMERAS," to be as follows:-
This Invention has for its object improvements in photographic cameras.
Panoramic views have heretofore in some cases been taken by photography,
the camera being adjusted first to take a portion of the view, and this being.
effected it is shifted or turned partly round, and the plate or sensitive surface
moved forward for the next portion of the view to be 'taken, and so on: Great
difficulty however is experienced in avoiding the appearance of join lines
between the different parts of the compound picture; to overcome this
difficulty I employ a screen which may conveniently be placed a short distance
in advance of the plate or sensitive surface; this screen, which limits the size
of the portion of the picture which is taken at each operation; is so made as
to shade off as it were the edges of each portion of the picture, spreading, so
to speak, the join lines between the several portions of the picture over a.

page_text: surface of some width instead of allowing the join to take place at a line of
inappreciable width. This I do conveniently by making the sides of the screen
of zig-zag form like saw teeth, and these are so arranged that the points at the
one side correspond to the centre of the notches on the other side; it will be
seen that these teeth act by intercepting a part of the light from the portion
of the plate or sensitive surface opposite which they come, whilst the portion
so shaded is twice exposed, first at one side and then at the other of the
screen. The distance between the sides of the screen are made adjustable so
that in case there are in the view any long horizontal lines, as in architectural
objects, such lines may be taken from end to end at one operation, otherwise
they would show angles at the joins. The same adjustment also serves to fit
the instrument to work with lenses of different apertures. In taking panoramic
views the slides for containing the plate or sensitive surface are necessarily of
considerable length, and as at present made with a rigid shutter and with a
rigid screen board on the camera the whole arrangement is somewhat unwieldy;
to obviate this, I apply flexible shutters to the slide so arranged that as the
leading edge of the slide is pushed forward into the camera it becomes
uncovered, and before it emerges on the other side it is again covered and
effectually shielded from the light.
sliding shutters are
When the slide with
According to the arrangement I prefer two flexible
employed, and they work in guide grooves on the slide.
its plate or sensitive surface is ready to be put into the camera the two shutters
meet at the leading end of the slide at the front of it, one shutter is then in
front of the plate or sensitive surface, whilst the other is behind the back of
the slide. As the slide is pushed forward into the camera a stud on the front
shutter catches a projection or stop on the camera, and the shutter is thus
pushed back, and it travels round a pulley or guide at the rear end of the slide.
and passes to the back. Before the leading end of the slide emerges from the
camera a stud on the other shutter catches a projection or stop at the further
side of the camera, and the shutter is thus drawn from the back of the slide
round a pulley or guide at the leading end of the slide so as to come in front
of the plate or sensitive surface and protect it from the light. In taking
photographic pictures difficulty is experienced in obtaining an accurate repre-
sentation of the sky at the same time that a foreground is taken, as unless
special precautions are taken the sky will be over exposed before the objects
in the foreground will appear. To obviate this difficulty, I employ an adjust-
able screen by which the light of the sky may be in great part intercepted;
this screen conveniently is placed at the lower part of the camera and some
distance in front of the plate or sensitive surface; its upper edge is arranged

page_text: to intercept very little light, but it becomes gradually more opaque in
descending from the edge. I prefer to make this screen of wires placed
horizontally, and held together so as to make a flexible fabric at the
upper edge of the screen; the wires are fine and far apart, but in passing down
the screen they are placed progressively nearer and near together until any
desired degree of opacity is obtained; the wires may also if desired become
gradually coarser in passing down the screen. In using the instrument when
it has been adjusted to take a view, by turning a button or otherwise the screen
is brought up until the sky is shaded to the extent the operator considers
suitable.
In order to insure the exposure of the plate or sensitive surface for the exact
time the operator determines to be suitable a clockwork apparatus is employed;
this clockwork gives motion to a disc in which holes are bored, and a peg
entering one of these holes holds the clockwork stationary until the time at
which is desired that it should start into motion, viz, when the exposure
commences this peg is in connection with a lever, which when acted upon by
means of another lever, or otherwise, gives motion to a stop so arranged that
when the peg is in a hole in the disc the stop is in such a position as to exclude
light from the camera. When the operator wishes to commence the exposure
he touches the lever to which the peg is connected, and so withdraws the peg
from the hole in the disc, thus he both starts the clockwork and moves the stop
so as to admit light to the camera; a spring causes the peg to bear constantly
on the surface of the disc, and when this has revolved so as to bring up another
hole the peg drops into it, the clock work is stopped, and the light again
excluded from the camera by the stop. Any desired time of exposure can
be obtained by having different distances between the holes and selecting a
suitable hole to put the peg into at the commencement of the operation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Victor Albert Prout in the Great Seal Patent Office on the
7th October 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, VICTOR ALBERT
PROUT, of Manor House, East Moulsey, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of April, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Victor Albert Prout, Her special licence that 1, the said Victor
Albert Prout, my executors, administrators, and assigns, or such others
as I, the said Victor Albert Prout, 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 "IMPROVEMENTS IN PHOTOGRAPHIC CAMERAS," upon the condition
(amongst others) that I, the said Victor Albert Prout, 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 dato of the said Letters
Patent.
NOW KNOW YE, that I, the said Victor Albert Prout, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention has for its object improvements in photographic cameras.
Panoramic views have heretofore in some cases been taken by photography,
the camera being adjusted first to take a portion of the view, and this being
effected it is shifted or turned partly round, and the plate or sensitive surface
moved forward for the next portion of the view to be taken, and so on. Great
difficulty however is experienced in avoiding the appearance of join lines
between the different parts of the compound picture; to overcome this
difficulty I employ a screen which may conveniently be placed a short distance
in advance of the plate or sensitive surface; this screen, which limits the size
of the portion of the picture which is taken at each operation, is so made as
to shade off as it were the edges of each portion of the picture, spreading, so to
speak, the join lines between the several portions of the picture over a surface
of some width instead of allowing the join to take place at a line of inappre-
ciable width. This I do conveniently by making the sides of the screen of
zig-zag form like saw teeth, and these are so arranged that the points at the
one side correspond to the centre of the notches on the other side; it will be
seen that these teeth act by intercepting a part of the light from the portion
of the plate or sensitive surface opposite which they come, whilst the portion
so shaded is twice èxposed, first at one side and then at the other of the screen.

page_text: The distance between the sides of the screen are made adjustable so that in
case there are in the view any long horizontal lines, as in architectural objects,
such lines may be taken from end to end at one operation, otherwise they would
show angles at the joins. The same adjustment also serves to fit the instru-
ment to work with lenses of different foci. This arrangement is shown in the
annexed Drawings, in which Figure 1 is a sectional side view; Figure 2, a
cross section; Figure 3, a side view; and Figure 4, a sectional plan of a
photographic camera having my improvements applied to it.
a and b are two frames forming the body of the camera, they slide the one
within the other for the purpose of focussing; the inner frame b carries the
lens c with its mounting, and the outer frame a receives the slide d, containing
the sensitive plate. The camera stands on a plate e (shown by dotted lines
in Figure 4) supported by a tripod to which it is connected by a screw bolt.
As shown in the Drawing the camera is made suitable for working with two
lenses of different focal lengths, and to admit of this, two bolt holes a', a', are
made in the frame a, and the screw bolt is put into one or other of these
holes, according as the long or the short focussed lens is employed. The
plate e has notches e¹, e', formed on its edge, into wbich spring clicks f; f, on
the bottom of the camera catch, one or other of the clicks acting according as
the bolt is placed in one or other of the bolt holes a; these notches e¹ and
clicks f, as represented in the Drawing, enable the operator to turn the camera'
after each exposure accurately through an angle of 30°. 9, 9, are the two
sides of the screen, before mentioned, for limiting the size of the portion of the
picture to be taken at each operation; they are made with saw like teeth as
already mentioned, but this may be varied so long as they are formed in such
manner as, at their extreme edge, to exclude but very little light, and gradually
to exclude more and more until at a short distance from the edge of the
screen the whole of the light is cut off; g', 9', are screws with milled heads
g³, g, these screws take into nuts fixed on the two parts of the screen g, and
by turning these screws the sides of the screen may be set nearer together or
further apart as desired, the parts of the screen 9 sliding in top and bottom
guides within the camera as is shown. In adjusting the screen for use, the
operator sets it by means of the focussing glass, so that when the camera is
turned round one division of the plate e, in either direction, the new image
obtained on the focussing glass, in consequence of the movement of the camera,
may join the former image without an interval and with a slight overlap equal
in width to the band shaded by the serrated edge of the screen. No further
adjustment of the screen is required unless, as before mentioned, the panoramio
view to be taken contains long horizontal lines, say of a building; in thi case

page_text: the operator in setting the camera places it so that such liues may be taken
from end to end at one exposure, and he separates the sides of the screen g to
the extent requisite, observing carefully the change required from the former
adjustment, say by counting the turns given to the screw heads g², this done,
and the screen being returned to its former adjustment and other usual adjust-
ments made, the exposure of the sensitive surface may be commenced, and this
is continued in sections until arriving at the section immediately before that
containing the long horizontal lines; this section is narrowed on the outer side
by traversing one part of the screen 9 by turning its screw to the extent
ascertained to be necessary in adjusting the instrument as already described.
For taking the section in which the horizontal lines occur, the image is widened
on each side by traversing both the screens outwards beyond the ordinary
adjustment to the same extent as before, and for taking the section next
following the adjustment is the same as for the section next before the long
lines, except that the screen is set to contract the image on its inner side. In
taking panoramic views the slides for containing the plate or sensitive surface
are necessarily of considerable length, and as at present made with a rigid
shutter and with a rigid screen board on the camera, the whole arrangement
is somewhat unwieldy; to obviate this I apply flexible shutters to the slide
so arranged that as the leading edge of the slide is pushed forward into
the camera it becomes uncovered, and before it emerges on the other side
it is again covered and effectually shielded from the light.
According to the arrangement I prefer, and which the Drawings show, two
flexible sliding shutters are employed, and they work in guide grooves on the
slide, When the slide with its plate or sensitive surface is ready to be put
into the camera the two shutters meet at the leading end of the slide at the
front of it, one shutter is then in front of the plate or sensitive surface whilst
the other is behind the back of the slide. A stud on the front shutter is
caught by a projection or stop on the camera, and thus as the slide is pushed
forward into the camera the shutter is pushed back and it travels round a
pulley or guide at the rear end of the slide and passes to the back. Before the
leading end of the slide emerges from the camera a stud on the other shutter
catches a projection or stop at the further side of the camera, and the shutter is
thus drawn from the back of the slide round a pulley or guide at the leading end
of the slide so as to come in front of the plate or sensitive surface and protect
it from the light. h, h', are the flexible shutters, they are conveniently made
by glueing strips of wood on to a sheet of leather, these shutters slide in guide
grooves i, in the rectangular frame d, which receives the sensitive plate or
surface; is a moveable back to the frame d, it closes the frame at the back

page_text: Չ
and is secured by suitable bolts or fastenings; 1, 1, are pulleys or rollers mounted
on axes at the ends of the frame d, and round them the shutters h and h¹ pass.
The sensitive plate or surface having been put into the frame d is secured by
replacing the back k, the shutter h' is then brought round to the back as far
as its groove i will admit, that is to say, so that only its leading edge is at the
front; the front of the slide being previously closed by the shutter h, it is put
into the camera by entering its bottom edge over the ledge m at the back of
the camera, and then dropping the spring pin n into the groove o at the top of
the frame d; after properly placing the slide by pushing down the incline P, the
catch is forced forward into a hole in the leading edge of the shutter h, and
all is then ready for commencing the exposure; then on pushing forward the
slide, the shutter h is moved along its groove and the sensitive surface exposed..
The distance for moving the slide between the successive exposures is regulated
by a spring catch r dropping into notches placed at suitable distances apart on
the slide. After the first exposure the shutter h' is retained by a projection h*
upon it coming against the side of the camera, and then as the slide is pushed
on the slide h¹ is drawn up from the back whilst the slide h is passing round
to the back. When the exposure is complete the catch q is drawn back, and
the shutter h again brought to the front, and the slide is then removed from
the camera. In taking photographic pictures, difficulty is experienced in
obtaining an accurate representation of the sky at the same time that a fore-
ground is taken, as unless special precautions are taken the sky will be over
exposed before the objects in the foreground will appear. To obviate this
difficulty I employ an adjustable screen by which the light of the sky may be
in great part intercepted; this screen conveniently is placed at the lower part
of the camera and some distance in front of the plate or sensitive surface; its
upper edge is arranged to intercept very little light, but it becomes gradually
more opaque in descending from the edge; this screen may be made of wires
placed horizontally at the upper edge of the screen, the wires are fine and far
apart, but in passing down the screen they are placed progressively nearer and
nearer together until any desired degree of opacity is obtained; the wires may
also if desired become gradually coarser in passing down the screen; or as I
prefer a thin sheet of glass may be employed ruled with lines at graduated
distances apart, the lines are then filled in with black varnish, and the upper
edge of the plate is coated with the same composition. In using the instru-
ment when it has been adjusted to take a view, by turning a button or other-
wise the screen is brought up until the sky is shaded to the extent the operator
considers suitable. In the Drawings this screen is marked s, and s¹ are racks
attached to it, they have a long pinion s gearing into them, and is a milled

page_text: head fixed on the axis of the pinion, by turning which the screen may be
raised or lowered. I prefer so to form the screens that whilst its upper edge
intercepts only say of the total light falling upon it, it increases gradually
and regularly in opacity until at the bottom of the whole light or there-
about will be shut out. In order to allow the axis of the pinion s to pass, the
frame a of the camera is slotted as it also is to pass the screws g¹ to exclude
light at these slot holes, slides z are used, they are as is shown made in two
parts fitting together with a dovetail so that the hinder part of each slide may
be removed when the short focussed lens is used, otherwise they would come
in the way.
In order to ensure the exposure of the plate or sensitive surface for the
exact time the operator determines to be suitable a clockwork apparatus
is employed, this clock work gives motion to a disc and a peg entering
1 hole in this disc holds the clockwork stationary, until the time at which it is
desired that it should start into motion viz, when the exposure commences;
this peg
is in connection with a lever, which when acted upon by means of
another lever or otherwise gives motion to a stop so arranged that when the
peg is in a hole in the disc the stop is in such a position as to exclude light
from the camera. When the operator wishes to commence the exposure he
touches the lever to which the peg is connected, and so withdraws the from
peg
the hole in the disc, thus he both starts the clockwork and moves the stop so
as to admit light to the camera; a spring causes the peg to bear constantly
on the surface of the disc, and when this has revolved so as again to bring up
a hole to the peg the peg drops into it, the clockwork is stopped, and the
light again excluded from the camera by the stop.
There are various methods in which the clockwork may be arranged in
carrying out my Invention of arranging clockwork in such manner as to
terminate the exposure at the end of any period to which the apparatus may
be set by the operator; for example, the disc to which the clockwork gives
motion, and which for landscape purposes may conveniently revolve once in
half an hour, may have a number of circles of holes upon it, the holes being
at equal distances apart, there being a different number in each circle, and
the clockwork and disc being arranged to be raised or lowered to bring one
or other of the circles of holes in the path of the pin.
A more convenient arrangement, and that which I have shown in the Draw-
ings, is to mount the disc on the axis driven by the clockwork in such a manner
that it will turn with friction on the axis as the hour hand of a clock is mounted,
there need then be but one hole in the disc, and the operator turns the disc
round in setting the apparatus so as to set this hole at the distance be requires

page_text: from the pin, then as the clockwork runs it brings the hole gradually up
toward the pin till presently the pin falls into it, and the exposure is terminated
and the clockwork stopped. t represents the case containing the clockwork
causing the axis t¹ to rotate once in half an hour; is a disc fitted with friction.
on this axis, and having also the pointer and handle & fixed to it; u is a lever
turning on a centre at u', and carrying the pin u³, which by a spring is caused
to rest on the disc t, and to drop into the hole therein when the hole comes
opposite to it. The pin can be lifted by pressing the finger on the outer end
of the lever u. vis another lever turning on a centre at v¹, and carrying at
its other end the stop w, and this stop by its own weight tends constantly to
move with its lever downwards so as to close the aperture by which the light
falls on the lens; when however the lower part of the lever u is pressed back,
it takes the lever vand the stop w with it, and the stop is kept up until the
pin us again falls through the hole in the disc t2, which will be at the end of
the exposure, for the operator immediately after raising the stop w turns the
disc t round by the handle until the pointer ts indicates on the graduated
circle t fixed on the camera the number of minutes or seconds required for
the exposure.
In witness whereof, I, the said Victor Albert Prout, have hereunto set
my hand and seal, this Seventh day of October, in the year of our
Lord One thousand eight hundred and sixty-five.
VICTOR ALBERT PROUT. (L.9.)