Iы- PROVEMENTS IN PHOTOGRAPHIC CAMERAS, AND IN THE APPARATUS CONNECTED THEREWITH
Year: 1856

page_text: LETTERS PATENT to John Benjamin Dancer, of the City of Manchester,
in the County Palatine of Lancaster, Optician, for the Invention of "Iы-
PROVEMENTS IN PHOTOGRAPHIC CAMERAS, AND IN THE APPARATUS CONNECTED
THEREWITH."
Sealed the 27th February 1857, and dated the 5th September 1856.
PROVISIONAL SPECIFICATION left by the said John Benjamin Dancer at
the Office of the Commissioners of Patents, with his Petition, on the
5th September 1856.
I, JOHN BENJAMIN DANCER, of the City of Manchester, in the County
Palatine of Lancaster, Optician, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FHOTOGRAPHIC CAMERAS, AND IN THE APPARATUS
CONNECTED THEREWITH," to be as follows:-
My said improvements refer to certain arrangements in the mechanical
construction of photographic, binocular stereoscopic, and other like cameras,
and likewise to peculiar boxes for introducing the prepared surfaces into
cameras and removing the same, enclosed in a case, which may be used alone,
or attached to the cameras. My improved binocular stereoscopic cameras have
a rack or chain movement to adjust or focus the image, which movement is
produced by a pinion passing through the centre of the box, the rack or chain
being attached to the division separating the camera box into two portions; also
a screw movement for raising or lowering the front part of the camera, to which

page_text: the lenses are attached; the level or levels are permanently affixed to the
camera at the front. I arrange a moveable diaphragm plate or plates, circular
or otherwise, pierced with various sized apertures, over which a suitable
shutter slides or rotates, or caps may be used, and a dark frame into which the
sensitised surfaces can be transferred by means of a sliding rod, or wire, with a
screw end or other catch to screw into or clip, and thereby elevate or slide the
several framed or other prepared surfaces into position. These improvements
are likewise applicable to photographic cameras generally, with the exception
of the rack or chain movement, which would require a different situation to
accommodate other arrangements.
Various methods are adopted to enable the operator to introduce and remove
the prepared sensitised plates, papers, or other surfaces.
I employ a box,
which may be permanently secured by its outer case to cameras. Each sensitised
surface is attached to a light frame sliding in grooves within the box, and each
frame has a hole with a screw part in the top centre. These frames can be
brought exactly under the dark frame in the camera, and by pushing down the
rod or wire, then screwing it into the frame, the plate can be thereby drawn up
into the dark frame without exposure to light, and so on with each plate, which
operation may be variously modified, as may also the means for holding and
moving the plates. The camera frame may be placed over a detached box
containing the plates, but the same is capable of many other arrangements.
This box has a graduated scale, and is placed in an outer case having a sight
hole opposite the scale, and is moved backwards and forwards by a rack or
chain movement. This outer case can be employed separately, or attached to
any of the usual photographic cameras.
SPECIFICATION
in pursuance of the conditions of the Letters Patent,
filed by the said John Benjamin Dancer in the Great Seal Patent Office
on the 5th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BENJAMIN DANCER, of the City of Manchester, in the County Palatine of
Lancaster, Optician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Benjamin Dancer, Her especial licence that I, the said John Benjamin

page_text: III
Dancer, my executors, administrators, and assigns, or such others as I, the said
John Benjamin Dancer, 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
PHOTOGRAPHIC CAMERAS, AND IN THE APPARATUS CONNECTED THEREWITH," upon the
condition, amongst others, that I, the said John Benjamin Dancer, by an
instrument in writing under my hand and seal, 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 Benjamin Dancer, 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 and accompanying Drawings (that is to say):-
My said Invention refers, firstly, to binocular stereoscopic cameras, and
consists in the use of a rack or chain movement situate in the centre thereof
for the purpose of adjusting the focus.
Secondly, in reference to cameras in general I apply a fixed or permanent
level.
Thirdly, in the use of revolving or sliding diaphragms or plates pierced with
apertures of various areas, which may at pleasure be brought into use.
Fourthly, in a method of altering the level of the lenses of binocular
cameras.
Another part of my Invention refers to apparatus whereby I am enabled to
expose successively a number of prepared plates or other sensitive surfaces
without the aid of a dark room, tent, or other such accommodation.
In order to effect this, I place the prepared or sensitive surfaces within a
box, from which they may be transferred by arrangements of mechanism to
a suitable position within the camera, or to a dark frame, capable of being
applied thereto.
And in order to explain fully the particulars of my said Invention, I will
now proceed to describe the accompanying Drawings.
Fig. 1 represents the section of a camera constructed upon the binocular
principle, and provided with a sliding part for adjusting the focus. The
outward box is shewn at a, and the sliding portion at b. To the former of
these, and in the middle, is adapted a fluted spindle c, capable of being turned

page_text: by a milled head. Around this spindle is coiled a chain d, similar to that of a
watch, one end thereof being attached to the sliding part at e and the other
at by means of a lever, which may be altered in position by screws, so as
to regulate the tension by turning the spindle, therefore the camera may be
lengthened according to the focus required. As a modification of the foregoing
arrangement, a rack may be employed instead of the chain, an ordinary
pinion working therein.
The next part of my Invention, namely, the application of a fixed or
permanent level to cameras generally, is also shewn at Fig. 1. It consists
of a circular chamber g containing the bubble, and enclosed by glass; but it
may be of other forms. The next part of my Invention is shewn at Fig. 1,
and also at Fig. 2, the latter of which represents the front of a binocular
camera. The lenses are supposed in this instance to project into the camera,
to the front of which they are attached by flanges, which flanges have
a fixed aperture as large or larger than that of the greatest area intended to be
used. Upon the flanges and excentrics thereto, discs h, pierced with apertures
1, 2, 3, 4, 5, are mounted by means of centre pins, by being turned upon
which each of the said apertures may at pleasure be brought coincident with
the centre of the lens. The discs are held in any required positions by means
of springs i, projecting points upon which take into indentations. I have
shown this portion of my improvements as applied to a stereoscopic camera,
but it will be evident that a perforated disc upon the same plan may be adapted
to those with one lens only. As a modification, the discs, instead of being
mounted so as to revolve, may be adapted to parallel guides, within which they
may be moved in a right line; and in reference to the series of apertures, I
would observe, that it will be found convenient to arrange them in areas of
known proportions, so that the operator may know the relative amounts of
light admitted. Fig. 2 also represents my arrangement for shutting off the
light from lenses of binocular cameras. Upon a centre pin situate between
the two lenses mounted a plate k, by the turning of which the two apertures
are closed at the same time; the extent of motion of the plate k is determined
by suitable stops. My method of altering the level of lenses in binocular
cameras is shewn at Fig. 1. The lenses are mounted upon a piece l, capable of
sliding in parallel guides; to this is attached a central nut m, within which is
a screw n; by turning this, therefore, the lenses may be raised or lowered as
required.
I now proceed to describe my method of transferring prepared or sensitive
surfaces.
Fig. 1 represents a longitudinal section of a camera with the box applied, in

page_text: which the prepared surfaces are placed; Fig. 3 is another section, taken at
right angles; and Figs. 4 and 5 are detached portions thereof. The camera
box is shewn at a, b, and may be sliding, folding, or of any other ordinary
construction; it is mounted when in use on the top of a box o, and retained
there in a definite position by means of suitable attachments. The box o is
open at the end A, and within it is situate a second box p, to the top of which
a sliding lid q is adapted. This box may therefore be slidden out from that
shewn at o, so as to constitute a receptacle for the plates similar to those used
for ordinary purposes, the light being effectually excluded by closing the lid q..
To the box o is adapted a cross shaft r, fluted, so as to act as a pinion at either
end upon racks s, attached to the sides of the box p; upon turning which shaft
therefore by means of the milled head the said box is caused to move inward
or outward. To the box o is attached a spring u, which carries two screws of
sufficient length to be capable of taking into nuts recessed into the lid q; by
these means, therefore, the said lid may be held stationary, and if the spindle r
be then turned, the box will be caused to move alone, thereby unclosing any
desired portion thereof. The back of the camera is furnished with grooves
suitable for receiving an apparatus v, similar to the usual dark frame. In this
case, however, it is not necessary that the back v' thereof should open, nor is
the slide required ordinarily employed for exposing the sensitive surface; it is
therefore represented as open at the face. At the bottom of this slide is an
opening w, extending across of sufficient width to allow the prepared plate to
pass, and at the top is a boss, within which a metal rod x is capable of being
moved upward and downward, in order to bring the sensitive surfaces to the
proper position of exposure, and to restore them when the impression has been
effected. A method I adopt for effecting this is as follows: -The prepared
surfaces (glass plates I will now suppose, but paper attached to millboard or
other substances may be used,) are placed in a series of frames y, which are
then arranged in the box p between a series of projections z. The tops of the
frames y are furnished with screwed sockets 6, which are capable of being
entered by screws formed on the end of the rod x.
Figs. 4 and 5 represent these parts detached, and shew the buttons 7, by
which the prepared surfaces are kept within the frames. The frames y are
made to one guage, and when drawn up into the frame v are pressed against
the surface v2 by means of springs, and the prepared surfaces will, therefore,
successively occupy the same vertical plane. The method of operating is as
follows: The box being charged with the frames y containing the prepared
surfaces, is placed within the outer box sufficiently far to allow the screws u
to be screwed into the sockets of the lid q, the focusing is then effected by

page_text: removing the frame and substituting another containing the ordinary ground
glass, the frame is then restored, the rod x being elevated above the bottom
thereof. The fluted shaft r is now turned so as to open the lid until No. 1 of
a scale marked upon the box p is seen through an aperture 8 formed in the
side of the outer box o, as indicated by dotted lines in Fig. 1; this indicates
that the frame y¹ is situate beneath the rod x, and as the lid q has been partially
withdrawn, the said rod may be thrust downward, so as to project into the
socket 6, and being then turned will be screwed therein, as shewn in Figs. 4
and 5. The frame y and its prepared surface may now be drawn upwards
into the frame v ready to be exposed by the removal of any ordinary cap
applied to the lens, after which it may be restored to the box by thrusting the
rod x downward, and the box p will subsequently be moved onward another
stage by the fluted shaft r, so as to bring the next frame y into position for
being raised.
Fig. 6 represents a dark frame of ordinary construction which may be used
in place of that shown at v when the usual collodion process is followed. I have
thus far described a method of carrying into effect one part of my Invention,
namely, the successive exposure of a number of prepared surfaces without the
aid of a darkened room, but I would remark that I do not limit myself to the
exact arrangement shewn and described, as other methods may be adopted upon
the same principle; for instance, it is not indispensible that the series of
frames-y should be employed, for the screwed sockets 6 may be attached direct
to the prepared plates or other surfaces by clamps, tapes, or other convenient
means; or the screwed sockets themselves may be dispensed with, and the rod x
furnished with a spring or other clip for holding them. I would also observe
that although I have described and represented the box p beneath the camera,
yet it is evident that it may be placed on the top, or either side thereof, if
desired. As another example of modification, I would observe that the box p
may be stationary, the rod being moveable so as to bring it over the several
frames y successively. This is illustrated at Fig. 7, which represents a camera so
arranged in section. The camera box is shewn at a, at the bottom of which
is an opening b; on the top is formed a slot c, over which is placed a bar d,
capable of sliding in parallel guides; this bar has a boss through which the
rod x passes.
Beneath the opening b is adapted a box p for the prepared
surfaces, one of them being furnished with a ground glass for obtaining the
focus. To use this apparatus, the operator (the cap being on the lens) opens
the sliding lid q and moves the bar d until a mark thereon points to No. 1
upon a fixed scale, the rod x is then depressed and the frame y elevated, as
before described in reference to Fig. 1; the lid q being now closed, the end f

page_text: of the camera is opened, it being made as a door for that purpose, and the
correct focus obtained, the image being upon the glass within the frame y;
this is now restored to the box p, and the bar d slidden onward until the mark
thereon is corresponding to No. 2 upon the scale, when the rod x is lowered
so as to elevate the corresponding frame and prepared surface, after which it
is moved backward with the bar d until the latter again corresponds with No. 1
on the scale, the point at which the focus was obtained, and the lid q being
closed, the exposure is allowed for the requisite time. In order to keep the
prepared surfaces constantly in the same plane, there is a fork-shaped piece g
attached to the bar d, provided with a groove, within which the frame and
prepared surface are drawn upward; the whole therefore moves together and
effects the desired object. In the foregoing arrangement the box containing
the prepared surfaces has been described as connected to the camera, but it
may be detached therefrom if desired, and this form may be more convenient
for large surfaces.
Fig. 8 represents, in section, a plan by which this modification may be
carried out. The outward box, as in Fig. 1, is shewn at o, within which is the
sliding frame box p, capable of being moved to and fro by the rack and
pinions s, r, and closed at top by the lid q, as before described. Upon the
upper part of the box are two ribs 9, between which the frame vis slidden
endways, projecting plates 10 thereon moving within grooves formed by
recessed parts of the ribs 9. In this situation the interior of the frame is
situate over the opening 11 in the box o, and the rod x being depressed, the
frame with its prepared surface is elevated into the dark frame v; a hinged
shutter 12 is then turned downward by means of an exterior lever, so as to
close the bottom orifice and thus exclude light, and the dark frame may then
be removed to the camera; previously to which, however, it will be necessary
in this instance to turn the pinion, so as to move the box p sufficiently to cause
the lid q to close the orifice 11.
Fig. 9 represents, in section, a modification of the foregoing separate
apparatus. The box containing the series of frames and prepared surfaces is
shewn at a provided with a sliding lid b of more than double the length, so
that an aperture c therein may be slidden from one end of the box to the other
without otherwise opening the said box. On either side of the said aperture
is a rib d, between which the dark frame may be placed by sliding it. When
not in use the lid b is moved until the aperture c is outside the end of the box
and the light is then excluded from the interior. When in this position the
dark frame is adapted and the lid slidden onward until the aperture c is even
with the frame and prepared surface desired to be lifted, when the rod x of

page_text: the former examples is lowered for that purpose, as before described, after
which the said aperture is moved beyond the end of the box and the dark
frame is removed. The light is prevented from entering at the bottom of the
dark frame by a hinged shutter, similar to that shewn at Fig. 8; or in place of
this shutter the frames containing the prepared surfaces may be provided at
their lower ends with projecting parts, which will close up the aperture of the
dark frame, as shewn at Fig. 10.
Having thus described and ascertained the nature of my said Invention, and
the manner in which the same is to be performed, I desire it to be understood
that I claim, as secured to me under the above in part recited Letters Patent,-
Firstly, as applied to binocular stereoscopic cameras, the use of a central
chain or rack and pinion for giving motion to one part thereof for adjusting
the focus.
Secondly, as applied to cameras in general, the use of a fixed or permanent
level.
Thirdly, the use of a revolving or sliding disc or discs perforated with holes
of different areas and acting as stops or diaphragms.
Fourthly, the apparatus described in reference to Fig. 2 for closing the
lenses of binocular cameras.
Fifthly, the use of a screw motion for elevating or lowering the lenses of
binocular cameras.
Sixthly, the use of a box or other such apparatus charged with sensitive
surfaces adapted to cameras, and from which such sensitive surfaces may be
transferred for exposure by rods or other apparatus temporarily attached
thereto.
Also, I claim the use of a box charged with sensitive surfaces detached from
the camera, to which, or to the dark frame, they may be similarly transferred.
Also, I claim, as applied to boxes or other chambers generally from which
sensitive surfaces are to be transferred, the use of separate frames, as illustrated
of Figures 1, 3, 4, 5, &c.
In witness whereof, I, the said John Benjamin Dancer, have hereunto
set my hand and seal, this Third day of March, in the year of our
Lord One thousand eight hundred and fifty-seven.
JOHN B. DANCER. (L.S.)