IMPROVE- MENTS IN PHOTOGRAPHIC APPARATUS
Year: 1855

page_text: LETTERS PATENT to John Cooke Bourne, of Holmes Terrace, Kentish
Town, in the County of Middlesex, Artist, for the Invention of "IMPROVE-
MENTS IN PHOTOGRAPHIC APPARATUS."
PROVISIONAL SPECIFICATION left by the said John Cooke Bourne at
the Office of the Commissioners of Patents, with his Petition, on the
27th March 1855.
I, JOHN COOKE BOURNE, of Holmes Terrace, Kentish Town, in the County
of Middlesex, Artist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PHOTOGRAPHIC APPARATUS" to be as follows:-
My Invention consists, in the first place, in rendering the apparatus more
portable by constructing it in such a manner that the box or case in which the
camera is contained may serve as a foundation on which the camera is sup-
ported when in use, and when out of use the front part of the camera may be
folded into the back part, and be placed in a compartment within the box.
1
My Invention consists, secondly, in constructing 'the 'box or case so that
when opened it may form a base for a tent, which is constituted by means of a
lath fixed on a centre or pivot at each angle of the inside of the box, the

page_text: several laths being raised and united at the top in pairs, so as to form, as it
were, two gable ends, in order to support a covering of suitable fabric, within
which the operations of preparing the sensitive surface developing the photo-
graphic picture, &c. may be performed, the camera remaining suspended from
the lid of the box during such operations. The said fabric or covering is con-
fined to the box or foundation by means of an elastic cord, and it has suitable
openings in it to admit of the head and hands of the operator being introduced
as required.
And my Invention consists, thirdly, in arranging and constructing the means
of adjusting the position of the lens of the camera, so as to ensure its move-
ment and ultimate position in a direction always in that of a curve, the radius
of which is the focal length of the lens. By this mode of adjusting the
position of the lens, the rays of light passing through the centre of the lens at
right angles to the surface thereof will fall upon the centre of the picture..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Cooke Bourne in the Great Seal Patent Office on the
27th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
COOKE BOURNE, of Holmes Terrace, Kentish Town, in the County of Mid-
dlesex, Artist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of March, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Cooke Bourne, Her special license that I, the said John Cooke Bourne,
my executors, administrators, and assigns, or such others as I, the said
John Cooke Bourne, 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 APPARATUS," upon the condition (amongst others) that I, the said
John Cooke Bourne, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention

page_text: 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 Cooke Bourne, 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, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
My Invention of "Improvements in Photographic Apparatus" consists, in
the first place, in rendering the apparatus more portable, by constructing it
in such a manner that the box or case in which the camera is contained may
serve as a foundation on which the camera may be supported when in use, and
when out of use the front part of the camera may be folded into the back part,
and be placed in a compartment within the box.
My Invention consists, secondly, in constructing the box or case so that
when opened it may form a base for a tent, which is constituted by means of a
lath fixed on a centre or pivot at each angle of the inside of the box, the several
laths being raised and united at the top in pairs, so as to form, as it were, two
gable ends, in order to support a covering of suitable fabric, within which the
operations of preparing the sensitive surface, developing the photographic
picture, &c. may be performed, the camera remaining suspended from the lid
of the box during such operations. The said fabric or covering is confined to
the box or foundation by means of an elastic cord, and it has suitable openings
in it to admit of the head and hands of the operator being introduced as
required.
And my Invention consists, thirdly, in arranging and constructing the
means of adjusting the position of the lens of the camera, so as to ensure its
movement and ultimate position in a direction always in that of a curve, the
radius of which is the focal length of the lens. By this mode of adjusting
the position of the lens, the rays of light passing through the centre of the
lens at right angles to the surface thereof will fall upon the centre of the
picture.
In order, however, that my Invention may be fully understood and
readily carried into effect, I will proceed to describe, by the aid of the
accompanying Drawings, first, the general arrangement and construction of
the apparatus in the several parts of which it is composed; and, secondly, the
manner in which the apparatus is intended to be used.

page_text: CONSTRUCTION OF THE APPARATUS AS SHEWN IN THE DRAWINGS:
Fig. 1 is a longitudinal elevation, shewing the camera as when in use, fixed.
on the lid of the box; Fig. 2 is a section of the same; Fig. 3 is a plan or
horizontal view of the lid of the box; Fig. 4 is a plan, shewing the box open
with the apparatus packed as when out of use.
Figs. 5 to 19-represent different portions of the apparatus detached: Fig. 5
shews the back of the slide case; Fig. 6 is a top plan, and Fig. 7 an under-
neath plan, of the bottom of the slide case; Fig. 8 is a front view, and
Fig. 9 a back view, of the lens end of the camera; Fig. 10 is a plan of the foot
of the lens standard; Fig. 11 shews the diaphragm slide, which is slidden: in
front of the lens; Fig. 12 shews the shutter slide which is slidden in front of
the diaphragm; Figs. 13 and 14 represent the box opened and the camera"
suspended from the lid, the laths raised and the tent cloth spread over: them;
Fig. 15 is a plan view of the triangular table on which the box rests, shewing
the mode of uniting and fixing the table an its legs; Fig 16-shews the
coupled legs folded together; Fig. 17 is an elevation of a triangular developing
stand; Fig. 18 is a plan of the same when folded; and Fig. 19 is a plan of
the same opened, as when in use.
Fig. 20 is a Diagram "illustrating the optical principle involved in my.
improved mode of adjusting the lens. In all these several Figures the same
letters of reference indicate corresponding parts.
a is the lid of the box, serving as a foundation for the camera; bis the bottom
of the same; c is the slide case of the camera, to the front side of whichi, is
attached the cloth or material for forming the sides of the "dark chamber" d;
e is a small perforated board: forming the front end of the dark chamber,
around the edge of which the cloth is fixed; f is a similar board, bolted to the
board e, and having an aperture for the insertion of the lens, as shewn at
Fig. 2; 9 is a standard fixed to the table or lid a of the box, on either of the
two curved brasse's h or h* (according as a longer or shorter 'focus is required),
by bolts through the foot of the standard and the curved slot of the brass,
allowing of the transverse movements of the bolts in the slot of the table.a, and
of their longitudinal movement in the slot i of the standard foot, whereby the
standard is adjusted on any curve corresponding to (or whose radius is) the.
focal length of the lens for the distance of the object to be taken; is a
pinching screw, by which the two boards e and f are fixed at any required.
height on the standard g; k and kisa telescope diaphragm' tube, by the
adjustment of which the diaphragm is fixed at the required distance from the
leus ; m is a diaphragm slide of wood, perforated with apertures of different

page_text: sizes, as shewn at Fig. 11. This diaphragm slide is inserted in an oblong
aperture formed transversely in the small tube n. For the purpose of inserting
it the tube n is partially unscrewed. The diaphragm slide is placed in its
position within the said aperture; the tube n is then rescrewed until the
diaphragm slide is firmly fixed in its position. ois a slide shutter; which is
intended to be moved over or in front of the diaphragm slide m, in a similar
oblong aperture, independently of the latter; p is the ordinary slide for
carrying the ordinary plate or picture surface; q is the focussing glass, shewn
in its position as when out of use; q* is a small spring fixed in the sliding
case c, fitting into a notch in the frame of the focussing glass to keep the latter
in its position when the camera is inverted; r is a tailboard attached by hinges
the bottom of the slide case c; t is a foot rigidly fixed to this tailboard;
u, u, are holding-down bolts, which pass through the tailboard and the foot t,
whereby they are firmly bolted to the lid a of the box; v is a swivel foot,
turning on the pivot or centre ; w is a bolt, by means of which the slide
case c is firmly fixed to the foot v at any required angle; x, x, are dovetailed
metal slides, capable of moving in the central groove y, shewn at Fig. 3;
2,2, are stays for keeping the slide case c in its required position, the foot
traversing on and being bolted to the brasses 1, 1; 2,2, are stays for keeping
the lens standard g in its required position, the foot traversing on and being
bolted to either of the curved brasses h or h, as the case may be; 2,2, are
brasses traversed by the holding-down bolts u, u, of the slide case c, and in
which the said bolts are fixed.
A, A, are laths fixed to the inside of the box by bolts B, B, and united near
their other extremity by a peg C; D is a lath fixed to the extremity of the
two former by bolts E, E. These laths are intended to form a kind of frame
for the tent. E is a bolt for attaching the box 6 to the triangular table; F
is the waterproof cloth or covering for the frame of laths to form the tent, and
is confined as required by a draw string beneath the box; G is an opening
through which the head and hands of the operator may be introduced; His a
draw string by means of which this opening may be contracted as required; I
is the triangle to which the box 6 is bolted; J, J, are sticks forming the legs of
the triangular table I, to which they are fixed by the pegs K, fitting into holes
on the heads of such sticks; L are elastic bands to retain the heads of the sticks
on the pegs K.; M is a steel spring to couple the legs at the lower part; N is
the triangular developing stand, constructed on the principle of a book hinge.
This triangular stand is constructed of wood, saturated with a composition of
asphaltum and Burgundy pitch dissolved in coal naphtha, for the purpose of

page_text: rendering it impervious to the chemicals used. At O the wood is hollowed out
for the purpose of inserting a level bubble.
3, 3, (Fig. 20,) are rays of light passing at right angles through the lens 7,
which is represented in three different positions on the curve 4, corresponding
with the curved brass h*, (Fig. 3,) and falling upon the centre of the picture
plane 5. By this disposition of the lens nearly the whole of the rays within
the angular compass of the same will fall upon the picture surface, as repre-
sented in the Figure. 6 (Fig. 4) is the box for containing the ordinary
plates, or the paper on which the pictures are to be produced; 7 is a box of
chemicals; 8 is a washing trough, in which the boxes 6 and 7 pack when the
instrument is out of use. This trough is made of wood, saturated with a
composition of asphaltum and Burgundy pitch dissolved in coal naphtha, and
beneath this trough is packed the sensitising solution bath; 9 is a gutta percha
bottle for distilled water; 10 is a similar bottle for ordinary water.
MANNER OF USING THE APPARATUS.
The first point to be attended to is to unpack the box and put the parts
together, so that they may stand up in the manner represented at Fig. 1. The
order in which I have found it convenient to do this is as follows:-I take the
triangle I from the box, open one pair of the legs J, insert one of the metal
pegs K in the hole at the head of the coupled legs, drop the loop of elastic
material Lover the head of the other coupled leg, and insert the corresponding
peg on the same side of the triangle in the eye of the same, and fix the
remaining legs to the triangle by the same means; I then place the box a, b,
on the table so formed, open the same, and take out the camera, pass the bolt
E through the hole in the box 6 and the hole I* of the triangular table I,
and screw the box firmly to the table by means of a nut underneath the latter;
I then drop the head of the foot bolts of the standard g into the circular holes
of that curved brass h or h* on which the said standard is required to be fixed,
and the foot bolts of the stays *, *, into the corresponding holes of the other
curved brass, and then fix these bolts temporarily; I then place the holding..
down bolts u, u, of the slide case c and the dovetailed brass slides a, a, in the
holes of the brasses 2, 2, and y, and the foot bolts of the stays z, z, of the slide-
case in the holes of the brasses 1, 1. The parts being thus stood up are now
ready for adjustment. The next point to be attended to is to adjust the parts
according to the required focus for the picture. The mode of proceeding with a
my improved apparatus for this purpose is as follows:-I first withdraw the
slide p from the case, and substitute for it the focussing glass q; I then draw

page_text: out the telescope diaphragm tube to the proper distance from the lens,
unscrew the small tube n sufficiently to allow of the placing in front of the
lens such opening of the diaphragm slide m as may be required; after this
I rescrew the tube n in order to hold it firmly in position, and place the
shutter slide o with its
diaphragm.
square opening in front of the opening in the
If the objects to be taken are equidistant from the camera, I place the lens
standard g in the centre of the curved brass h or h*, firmly screw the foot and
stay bolts, adjust the slide case square with the swivel foot v, and firmly screw
the two bolts and w, to hold it in position and direct the camera towards
the object to be taken; I then proceed to focus the camera in the ordinary
way, afterwards firmly screwing the holding-down bolts u and the stay bolts.
If the objects to be taken are of unequal distances from the camera, and of
a perpendicular character, as, for example, the side of a street viewed obliquely,
I ascertain the mean focal length for the objects to be taken, slide the lens
standard g on the curved brass (say h*) in the direction of the nearest object,
and by means of the slot i in the foot of the standard (see Fig. 10), I adjust the
latter upon that curve the radius of which is equal to the mean focal distance,
whereby the rays passing at right angles through the centre of the lens fall
upon the centre of the picture surface, or such slightly flatter curve (about
one-tenth longer radius) as may be desirable for regulating the relative
definition of different parts of the picture, or for using the whole angular
compass of the lens; I then loosen the screw w of the swivel foot v, so as to
allow of the slide case c being placed, at such angle with the lens as may be
requisite for focussing the objects of different distances. This will be illustrated
by Fig. 20, in which the group of rays 3' are supposed to emanate from an
object distant ten feet, the coloured group 3 to emanate from an object
distant fifty feet, and the rays 32 from an object distant two miles; 5 repre-
senting the picture surface; 33 represents the mean focal distance. The
required focus being thus arranged, I fix the instrument by firmly screwing tho
holding-down and stay bolts u and z.
If the objects to be taken are of a horizontal character and of unequal
distances from the camera, as, for example, a level country, I place the lens
standard g in the centre of the curve, as in the former instance, and fix it by
the foot and stay bolts, ascertain the mean focal distance, raise or depress the
lens on the standard, as required, and fix it by the bolts and nuts j,j, then
incline the slide case c backward at such angle with the lens as will properly
focus the respective parts of the picture, and fix the instrument as before. If

page_text: the lens is required to be adjusted perpendicularly on a curve corresponding
with its focal length for the objects to be taken, (for the reasons before given
in describing the horizontal adjustinent of it,) I loosen the foot bolts of the
standard g, and slide the foot longitudinally on the box in the direction and
degree required and then tighten the foot bolts. Thus, by the vertical move-
ment of the lens on its standard and the inclination of the standard itself, I
effect the adjustment of the lens vertically on the required curve, as in the
former instance I adjusted the lens horizontally by the transverse movement
of the standard on the curved brass, as before described; or the two adjust-
ments (vertical and horizontal) of the slide case may be combined; according
as the subject may require. The camera being thus focussed, I open the box,
leaving the camera already adjusted suspended from the lid, as shewn at
Figs. 13 and 14; I then raise the laths A, A, and attach thereto the lath D,
and spread over them all the waterproof material F, to form the tent. Within
this tent I perform the usual chemical manipulation. I first prepare the
plate in the usual way,
then place it in the dark slide p, remove the tent
covering and laths, close the box a, b, substitute the slide p for the focussing
glass q, close the aperture in front of the lens 7 by partially withdrawing the
slide shutter o, open the shutter of the slide: in the usual way, and open
the aperture in front of the lens, by returning the slide shutter o to its
former position. When the plate has been exposed in this manner a sufficient
length of time, I move the slide shutter o forward until the aperture in front
of the lens is again covered; I then re-form the tent, and proceed to develope
the picture therein in the usual manner.
Having thus described the nature of my Invention, and the manner in which
the same is to be performed, I would have it understood that I do not mean or
intend to confine myself to the precise forms and arrangements of the parts
represented and described. I would also remark that although I have found
it necessary for the sake of making evident the mode of constructing and using
my improved apparatus to describe at the same time several well-known parts
of photographic apparatus, yet I do not claim such parts as of my Invention;
but I do claim as of my Invention,
First, the construction of the apparatus so that the box or case a, b, may
serve as a foundation or support for the camera when in use, and for packing
the folded camera therein, as described; also attaching the slide case to the
box by means of the swivel foot v, x, and hinged tail-board r, admitting of the
inclination of the slide case as required.
Secondly, in the construction of the apparatus whereby a tent may be formed

page_text: upon the box a, b, when opened, while the adjusted camera remains suspended
from the part a of the same, as described.
And, thirdly, in the adjustment of the lens on a curve the radius of which
is the focal length of the lens for the distance of the object to be taken, for the
purpose herein-before described; also the means whereby such adjustment is
effected (viz.), horizontally, by the combined movements of the foot bolts of
the lens standard in the slot of the curved brass and in the slots i, i, of the
standard foot, and vertically by the movement of the foot bolts of the standard
in the said slots i, i, combined with the vertical movement of the lens board f
on the standard g, as described; also the arrangement by which the end of the
camera e is bolted to the board f and open standard g, admitting of a vertical
movement of the boards on the latter.
In witness whereof, I, the said John Cooke Bourne, have hereunto set
my hand and seal, the Twenty-seventh day of September, in the year of
our Lord One thousand eight hundred and fifty-five.
Witness,
WILLIAM SPENCE,
50, Chancery Lane.
JOHN COOKE BOURNE. (L.S.)