IMPROVE- MENTS IN PHOTOGRAPHIC APPARATUS
Year: 1860

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County
of Middlesex, Engineer & Patent Agent, for the Invention of "IMPROVE-
MENTS IN PHOTOGRAPHIC APPARATUS."-A communication from abroad by
Mr. Charles Gustave Anthoni, of 29, Boulevart St. Martin, Paris, in the
Empire of France, Mechanician.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 10th
December 1860.
'I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer & Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PHOTOGRAPHIC APPARATUS," to be as follows:-
This Invention relates to a novel arrangement of the dark chamber used in
photography, which is only one-fourth the size of ordinary dark chambers,
and also serves as a laboratory for the damp collodion process in the taking
and the developement of proofs in. the open air. These operations are per-
formed with ease and rapidity by means of two troughs of gutta percha placed
on the two sides of the dark chamber. The one of the troughs which is át the
opposite side to the object contains a bath of azotate of silver, the other con-
taining a bath of sulphate of iron, is placed at the under part of the dark

page_text: chamber. By this disposition of the apparatus the sheet of glass treated with
collodion after having been fixed on the hooks to maintain it in position
during the operation is dipped in the solution of azotate of silver placed at the
back part of the apparatus, to which is imparted a rocking movement on a
hinge connected with the dark chamber. After the sensitive impression the
collodioned sheet of glass is submitted to the action of light; it is then only
necessary to submit this sheet of glass to the bath of sulphate of iron to
produce the developement of the proof. For this purpose the sheet of glass
bearing the impression is unhooked by means of mechanism placed on the
exterior of the box, which, when disengaged, is pushed by the suspending
hooks, which are at same time inclined, and give a movement to the glass in
the apparatus. This movement being controlled and rendered sure by the
mechanism the sheet of glass falls into the bath of sulphate of iron which
is underneath. The impression being developed on the sheet of glass it is
withdrawn from the bath and placed in a third trough containing water, where
it is left until the impression is fixed.
SPECIFICATION in pursuance of the conditions of-the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 10th
June 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer & Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of December, in the year of our Lord
One thousand: eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark,. niy
executors, administrators, and assigns, or such others as I, the said William
Clark, 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," a 'communication from, abroad by Mr., Charles Gustave Anthoni,
of .29, Boulevart St. Martin, Paris, in the Empire of France, Mechanician,

page_text: upon the condition (amongst others) that
the said William Clark, 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 per-
formed, 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 William Clark, 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 state-
inent thereof, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
:-
This Invention relates to a novel arrangement of the dark chamber used in
photographic operations, which is only one-fourth the size of ordinary dark
chambers, and also serves as a laboratory for effecting the sensitive process,
& the taking and developement of proofs in the open air with damp eollodion
whereby these operations are performed with ease & rapidity. On two s
of the dark chamber are placed two gutta percha troughs. One of the troughs
contains a bath of azotate of silver, the other a bath of sulphate of iron. The
troughs are hollowed at those parts where the glass.plate, is placed, & they are
provided with external flanges, which allow of an inclination of 45°, & even
niore for certain positions without the liquid therein contained. being spilt,
which renders the apparatus. suitable for transport. By this disposition the
apparatus, as shown in the annexed Drawings, the glass plate treated with
collodion, may be successively dipped into the two baths without its being
taken out of the dark chamber, the motions of said plate being suitably
controlled by mechanism actuated from the exterior of the box.
In the annexed Drawings is represented the photographic apparatus of this
Invention, which I term "mechanical laboratory," wherein Fig. 1 shows. 'a
side elevation of the dark chamber; Fig. 2, a central vertical section of the
same; Figs. 3, 4, & 5, show details, which will be herein-after described.;
& Fig. 6, a section of part of the dark chamber, also showing details herein-
after described. In the different Figures the same letters and figures of
reference represent the like parts where they recur.
a, dark chamber; b, collapsible part for regulating the position of that part
of the dark chamber which carries the object glass, in order to fix the point or
focus; c, opening for receiving the plate, the space for the object glass in
which is made eccentric, so as to permit of being placed opposite to either of

page_text: the two sizes or dimensions comprised by it. When the apparatus is not in
use the glass plate is turned up, so as to permit of the object. glass being
lodged in the apparatus, & leaving the room free for the grooved boxes;
d, trough-holding frame hinged at point e; f, screw for intercepting the
luminous rays while the sensitive process takes place, which screw is with-
drawn at the moment of the operation by. means of the strap 9 attached
thereto; h, yellow glass fitted in the screen, for overlooking the taking of the
sensitive impression of the collodioned glass plate in the bath of azotate of silver;
i, i, i, three hooks of horn, whalebone, silver, or other suitable material,) fixed
on two spindles ; & j; these three books, one of which is fixed at the upper,
and the other two at the lower part of the apparatus, are intended.to support
the glass plate when treated with collodion; fixed hooks i may also be used,
as in Fig. 6, for receiving the sheet from the movable hooks i, and transmitting
it to the bath of sulphate of iron, which movement is performed as with
common hooks; k, k³, knobs on the ends of the spindles ; & j¹, the one k¹ for
operating j¹ without the box being opened, & the other, k, acting as a counter-
us represented at Figs, 3, 4, & 5. Spiral springs 1, 13, secured at one end
to a small block, and at the other to spindles ; & j¹, tend to rotate the said
shafts in the direction shown by the arrows, but this motion is limited by
notches in the discs m & m² fitted on the spindles ; & j' coming in contact
with stops n; n². The disc m¹ has also a small ratchet, which, when acted
upon, will rotate the shaft, so that the horn hook shall descend and cause the
collodioned glass to meet two small blocks o, whereby it is detached from the
hooks; p, the collodioned glass; q, lateral guides, which are caused to assume
clifferent positions for guiding the glass in either direction; s, hook for with-
drawing the glass plate from the bath of sulphate of iron; t, hooks, which are
caused to assume the position of hooks i & i by turning on their joints. These
hooks are four in number, two at the upper & two at the lower part, and
arranged so as to support either size of roughed glass. The hooks i may
also be brought nearer to each other, so as to be applicable for smaller sized
glasses, for which purpose the upper hooks i and axes j are placed at u;
v, gutta percha trough fitted to the trough carrier d, and turning on hinges
x, x. It contains the bath of azotate of silver, and is provided with a flange,
the lower part of which being of great depth constitutes the reservoir. The
space for the hooks, and also for the collodioned sheet of glass is cut out of the
back of the trough; z, second trough, also of gutta percha, fitted. in space y,
which is suitably arranged for the purpose. This and the trough may be
closed. by means of a plug of gutta percha, to prevent any motion or wash of

page_text: the liquid; they are also divided into compartments by vertical partitions,
which arrangement permits of the baths being inclined to an angle of ninety
degrees without spilling their contents. In order to incline this trough in
both directions, the space'y is connected by hinges to two wooden plates 2 & 3,
which arrangement permits of a rocking motion, represented in red lines,
Fig. 1, for the purpose of spreading the solution of sulphate of iron (SO, FeO)
on said plate evenly throughout its surface; 4, hook secured to the trough v,
engaging in bar 5 when the trough-holding frame is open & the point or focus
is being fixed; 6, iron plate attached to the under part of the dark chamber
carrying the tripod 7. There are, besides, small slotted links 81, 83, 8³, for
regulating the position of the several parts of the apparatus, & hooks 9 for
connecting the same.. On starting for a trip I place in the space 10,
represented in red outlines, Fig. 1, a box containing twelve sheets of glass,
and one rough sheet, & also gutta percha trough, with water therein, for
receiving the proofs as they are taken out of the bath of sulphate of iron.
The grooved gutta percha trough may be dispensed with, in which case the
space is made available for carrying bottles in its. stead. The proofs just
obtained are placed in the same grooved box with the cleaned sheets, care
being taken to separate them from the latter by a movable partition made to
move a notch each time a new proof is obtained.
I will now proceed to describe the manner in which the Invention is carried
into effect:-After setting the apparatus upon its stand, I place the link 8¹ at
the index, so that the hinges of the trough-holder may be on a horizontal line,
and I open the trough by causing it to turn on its hinges x, x¹; the sheet of
glass after being previously treated with collodion is placed between the hooks
i, i, & the trough is again closed by the hook 9; the trough and trough
holder are then lowered by turning them on the hinge e until they are below
the horizontal line, which causes the collodioned sheet to be at once immersed
in the bath of azotate of silver. The trough then has a rocking motion imparted
to it, which is regulated by the link 82,, & after about one minute of such
rocking the trough is hooked up by the hook 4 taking into bar 5, & the
apparatus is fixed at the desired point. For this purpose the hooks t, t, are
raised, and a plate of rough glass placed upon them; by this means the fixing
at the required point is effected. This being done the rough glass is removed,
the hooks t, t, again raised, and the trough and trough-holder returned to their
former position. The screw fand the cover are now removed, and the sheet
of glass is acted. upon by the light. The cover is again placed over the object
glass, and the sheet of glass bearing the impression dipped into the bath of

page_text: sulphate of iron. For this purpose the apparatus is inclined in such manner
that the link 83 points to the index by means of the ratchet, the hook i is
lowered, & the further motion of the sheet of glass arrested by the blocks o,
the hook continuing to fall, at the same time the disengaged sheet is pushed
back by the end of the hook which acts as a spring. The hook is then again
lifted, and the sheet of glass guided by q & falls, as seen in red outlines, into
the bath of sulphate of iron, to which is imparted a rocking motion, shown in
red outlines, Fig. 1; the hooks being previously placed in position, the small
'loor 1 is then opened, the trough removed, and the sheet of glass taken out
from the bath by means of the hook. The sheet of glass upon which the
image is developed is placed in the grooved box after being washed sufficiently
when water can be had.in abundance; when water is scarce, the sheet should
be put in this box, which is previously filled with water. In this manner tho
sheet of glass will continue damp to the moment when the operation is to be
completed.
•
This apparatus is especially applicable for taking portraits, as the fixing of
the point or focus generally takes place the sheet of glass has received the
'sensitive impression, or has been rendered sensitive.
space for
For obtaining stereoscopic views I add to the collapsible chamber a fixed
partition terminating by another partition turning on a vertical axis secured in
the collapsible chamber. An external knob on the end of this axis permits,
after the sheet of glass has received the sensitive impression and the trap-door
been lifted up, of turning the movable partition, so as to bring it to the
extension of the stationary one, such movable partition then coming within
one-twentieth of an inch of the glass. In the half sheet apparatus two
stereoscopic or four views can be taken; for this purpose the fixed partition is
made in the form of a cross, the movable vertical partition having
admitting the horizontal movable partition. This arrangement of partition
may also be applied when a greater number of object glasses are to be used
simultaneously. As regards the transmission of the sheet of glass, the
partitions can be moved round by means of knobs, so as to be receded from
the bottom of the trough on point e. This chamber is placed between the
trough-holding frame and the dark chamber, which arrangement permits of
dispensing with hooks t, t, & the screen f, and in this case the bottom of
the trough should be provided with a yellow glass, to allow of the apparatus
being fixed at the point or focus in a strong light, at other times the point or
focus is obtained before commencing the operation by means of a plate of
rough glass placed on the hooks i.

page_text: Having described the nature of the Invention, & the manner of performning
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is, the arrangement of parts con-
stituting the mechanical laboratory above described, for operating in the open
air with damp collodion, & also the various arrangements of parts which I
have described & represented in the annexed Sheet of Drawings, for the
purposes herein-before set forth.
In witness whercof, I, the said William Clark, have hereunto set my
hand and seal, this Eighth day of June, in the year of our Lord
One thousand eight hundred and sixty-one.