IMPROVEMENTS IN STEREOSCOPES
Year: 1853

page_text: LETTERS PATENT to Antoine Francois Jean Claudet, of Regent
Street, in the County of Middlesex, Photographic Artist, for the
Invention of "IMPROVEMENTS IN STEREOSCOPES."
Scaled the 20th day of May 1853, and dated the 23rd March 1853.
PROVISIONAL SPECIFICATION left by the said Antoine Francois
Jean Claudet, at the Office of the Commissioners of Patents, with
his Petition, on the 23rd March 1853.
1, ANTOINE FRANCOIS JEAN CLAUDET, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN STEREOSCOPES" to be as
follows:-
This Invention of improvements in stereoscopes has for its object,
firstly, the producing of pleasing and novel optical illusions; and,
secondly, so constructing and combining the several parts of which the
instrument is composed that it may be collapsed and brought into a
small compass, so as to be rendered more conveniently portable than
ordinary rigid instruments.
One of the optical illusions which I propose to produce by means of the
first part of my improvements is effected by adapting to the interior of the
stereoscope a mirror or looking glass, in which the picture, when placed

page_text: .
at the bottom of the instrument, as usual, is reflected, so that when an
object, say, for instance, a portrait, is observed through the lenses, the
person represented will be seen in a natural position and not reversed;
the mirror is placed at an angle of 45 to the plane of the picture, and
the lenses or eye pieces must therefore be placed at the back instead of
at the top of the stereoscope; so that the line of sight is parallel with
the plane of the picture, and the angle of incidence being equal to the
angle of reflection, as is usually the case. Another improvement, which
may be used in conjunction with the above, consists in the adaptation
to the eye pieces of a sliding piece, which has holes or apertures made
therein, and so arranged that first one eye piece and then the other may
be closed. The pictures, instead of being made simply stereoscopic in
the well-known manner, are made so as to shew various actions; for
instance, to represent a man taking off and putting on his hat, one
picture must be made with the hat on, and the other with the hat off
and in the hand. Upon observing the two pictures together in the
stercoscope, and moving the slide of the eye pieces backwards and
forwards, the figure will appear as if he were taking off his hat. A
variety of other illusions of moving figures, as dancing figures, athletoe,
boxing matches, &c., may be made. An increased effect and great
variety will be produced by combining a number of pictures together in
the form of a cross, so arranged as to exhibit two pictures only together.
Two series of pictures arranged in crosses must be employed, and the
crosses so made are mounted on centres in the body of the stereoscope,
and are actuated by the moving slide of the eye piece, which, by means
of a lever and click and ratchet wheels, will cause the crosses to turn
alternately, and present pictures of different figures, or the same figure
in different positions. The moving parts may be actuated by clock-
work, or other self-acting mechanism, so that the different changes in
the attitude of the figures will take place without the assistance of the
observer. The instruments, with my improvements attached to them,
may be made either rigid, as is usual, or put together in such a manner
as to admit of their collapsing or folding for the purpose of shutting up
into a small compass.
A variety of plans may be devised for enabling
the instruments to be folded up, and some of them I propose to con-

page_text: .
struct in such a manner that immediately the fastening, which holds
the instrument in a closed state, is undone, all the parts will be at once
made to assume their proper position for viewing a picture. One of
the simplest arrangements consists in mounting the eye pieces in a flat
bar attached to a flap which is hinged to the lid of a box, which may
form part of the case of a stereoscope picture. The hinged flap has
openings made therein immediately below the lenses for the purpose of
looking through, and is provided with an overhanging piece for par-
tially excluding the light; the lid of the box is prevented from opening
too far by means of a strap, which holds it up at right angles from the
bottom; the hinged flap, which carries the eye piece bar, is also sup-
ported in a line parallel with the bottom of the case (and therefore
with the picture) by means of one or more vertical supports. When
the lid of the case is lifted up, the eye piece bar at one rises into its
proper position by the force of an elastic strap or India-rubber spring.
By the above arrangement I am enabled to get a complete stereoscope
into a case about 6 inches long, 3 inches wide, and inch thick;
the case may be made to open either like a book, the hinges being at
one side;"'or, by somewhat modifying the internal construction, it may
be made to open' from the middle, like a pair of folding doors, the
hinges in this case "being at each end. Another form of making the
instrument consists in attaching the eye pieces to two flaps, which have
holes to look through made therein, and are hinged to a central vertical
partition, which is made moveable in a vertical guide, so that it may be
moved up or down for the purpose of altering the focus when required.
In this instance the lenses are mounted in cells attached to the upper
ends of flexible tubes, which are kept extended by means of coiled or
The sides of
spiral springs when not compressed in the case or box.
the box are hinged to the fixed central part, and when the hook
or fastening which keeps them closed is undone the pressure of the
coiled springs of the eye pieces will force the sides down into a hori-
zontal position, and at the same time cause the hinged flaps to be raised
into a horizontal position by India-rubber or other elastic springs.
will now be understood that when the clasp or fastening which keeps
the sides of the' case closed is unfastened, all the several parts will at
.:
It

page_text: once spring into their proper position for viewing the pictures, without
any assistance from the observer. These plans of constructing portable
stereoscopes may be considerably varied. I do not intend, therefore, to
confine myself rigidly to these precise arrangements, which will be found
to possess the same principle of construction, although carried out in a
somewhat different manner, viz., that all the parts are connected to-
gether, and all fold up and lie in one case, the top and bottom of which
forms part of the instrument.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Antoine Francois Jean Claudet, in the Great Seal
Patent Office, on the 23rd September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ANTOINE FRANCOIS JEAN CLAUDET, of Regent Street, in the County of
Middlesex, Photographic Artist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of March, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Antoine Francois Jean Claudet, Her
special licence that I, the said Antoine Francois Jean Claudet, my
executors, administrators, and assigns, or such others as I, the said
Antoine Francois Jean Claudet, 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
upon the condition (amongst others). that I, the said Antoine Francois
Jean Claudet, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Inven-
tion, 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
IN STEREOSCOPES,"

page_text: months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Antoine Francois Jean Claudet,
do hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer
tained 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);
This Invention of "IMPROVEMENTS IN STEREOSCOPES," has for its object,
firstly, the producing of pleasing and novel optical illusions by means
of a peculiar construction and arrangement of some of the parts, which
are made moveable so as to impart to the picture the appearance of
moving figures.
.
My Invention consists, secondly, in so constructing, and combining
the several parts of which the stereoscope is composed that the instru-
ment may be collapsed and brought into a small compass, so as to be
rendered more conveniently portable than ordinary rigid stereoscopes.
One of the optical illusions which I propose to produce by means of
the first part of my improvements is effected by adapting to the interior
of the stereoscope a mirror or looking glass, in which the picture, when
placed at the bottom of the instrument, as usual, is reflected, so that
when the picture of any object, say, for instance, a portrait or a land-
scape, is observed through the lenses, the picture or person represented
will be seen in a natural position, and not reversed, as is usually the
case. The mirror is placed at an angle of forty-five degrees to the
plane of the picture, and the lenses or eye pieces must therefore be
placed at the back instead of at the top of the stereoscope, so that the
line of sight is parallel with the plane of the picture; and the angle of
incidence being equal to the angle of reflection, the image is reflected
to the eyes by the inclined mirror. An instrument constructed on this
plan is shewn at Figures 1, and 2, Sheet I.. of the accompanying: drawings,
a, a, is the lid of the box or case of the instrument; b, b; is the mirror,
placed at the proper inclination or angle to the bottom c, of the instru-
ment, where the picture is to be placed. The eye pieces are shewn
at d, d, the line of sight being denoted by the horizontal dotted line.

page_text: A lid or shutter at e, and another one at f, are hinged to the mirror
for the purpose of shading out extraneous light, and to prevent the
reflection of surrounding objects in the mirror. Instruments con-
structed on this principle may either be made rigid or collapsible, as
shewn in the drawing. As the mode of rendering the instrument
collapsible forms part of the second head of the Invention, it will be
more fully explained hereafter.
Another improvement, which has for its object the production of
pleasing optical illusions, is shewn in Figures 4, and 5, and consists in
the adaptation to the eye pieces of a sliding piece, which has holes or
apertures made therein, and so arranged that first one eye piece and
then the other may be closed by moving the sliding piece backwards
and forwards in its groove.
The pictures, instead of being made simple stereoscopic in the well-
known manner, are made so as to show various actions; for instance,
to represent a man taking off and putting on his hat, one picture
must be made with the hat on, and the other with the hat off and in
the hand.
Upon looking in the stereoscope, and moving the slide of the eye
pieces backwards and forwards, the figure will appear as if he were
taking off his hat.
This is the most simple form of stereoscope, to produce this kind of
illusion, which is effected by alternately opening and closing first one
and then the other aperture for the eyes, the action for so doing being
so quick as to be scarcely perceptible to the eye of the observer. A
variety of other illusions of moving figures, as dancing figures, athletæ,
boxing matches, may be made. An increased effect and great variety
will be produced by combining a number of pictures together in the
form of a cross, so arranged as to exhibit alternately under each eye
from different positions, so that the observer may, in succession, see eight
different pictures, all in different attitudes. By this means the change
in position or attitude of the figures will not appear so sudden and
so abrupt as when only two pictures are exhibited.
The two series of pictures arranged in crosses must be employed,
and the crosses are mounted on centres in the body of the stereoscope,

page_text: and are actuated by a coiled spring, which must be wound up occasion-
ally for that purpose.
Fig. 4, is a longitudinal vertical section of a stereoscope constructed
upon the plan just described; and Fig. 5, is a transverse vertical
section of the same; a, a, is the case of the instrument; d, d, the eye
pieces; g, g, are a pair of crosses, each composed of four pictures
representing the figures, say two boxers in different attitudes; these
crosses are mounted on centres which turn in holes made in the sides
of the case.
Each of the axles of these crosses carries a pulley h,
which is worked by means of a band driven by geering n, which is
rotated by a coiled spring, enclosed in a closed box m. The crosses g, g,
are locked in their required positions by means of catches p, which are
raised out of contact with the crosses by the sliding bar , to permit of
the action of the spring.
This sliding bar k, has two holes made in it, for the purpose of
closing or obscuring the apertures of each of the eye pieces alternately.
It will now be seen that if the observer, while he is looking through
the eye pieces at the pictures, will move the sliding bar k, the driving
band of the pulleys will cause the crosses to rotate, and thus every time
the bar , is moved backwards a different picture will be presented
under one or other of the apertures.
The instrument with some of my improvements attached to them,
may be made either rigid, as is usual, or put together in such a manner
as to admit of their collapsing or folding for the purpose of shutting
up into a small compass.
In Figures 1, 2, and 3, already referred to, I have shewn my
improved reflecting or mirror stereoscope, constructed in such a manner
as to be collapsible; a, a, are the lids of the case; c, c, the bottom
thereof; the eye pieces d, d, are collapsible, being furnished with a
helical spring internally, and are attached to a flap g, which is hinged
to the bottom c. The mirror b, is connected by the lid e, to the top
edge of the flap g, and when the stereoscope is closed as shewn at
Fig. 3, the parts e, and b, fold flat against the part g, and the part f,
against the back of the mirror b. The parts a, are sustained in their
place by means of the struts h, and the other parts are held up by means
of suitable catches as shewn.

page_text: A variety of other plans may be devised for enabling the instruments
to be folded up, and some of them I propose to construct in such a
manner that immediately the fastening which holds the instrument in
a closed state is undone, all the parts will be at once made to assume
their proper position for viewing a picture. One of the simplest
arrangements consists in mounting the eye pieces in a flat bar attached
to a flap, which is hinged to the lid of a box, which may form part of
the case of a stereoscope picture.
This construction is shewn in Figures 6, 7, 8, and 9; a, is the lid of
the box; c, the bottom in which the stereoscopic picture b, is to be
placed. The eye pieces d, d, are attached to the flap g. The horizontal
flap g, is supported by the vertical flap f," which is held in its place by
the hooks and eyes i, i.
"
.
Fig. 6, is a plan view of the stereoscope.
Fig. 7, is a cross section.
Fig. 8, is a longitudinal section of Fig. 7, looking to the right hand,
and Fig. 9, is a perspective view. of the instrument closed, one of the
ends thereof being removed to shew the interior.
The. hinged flap g, has openings made therein immediately below the
lenses for the purpose of looking through, and is provided with an
overhanging piece, 'for partially excluding the light and preventing it
from falling on the daguerreotype plate, at an angle which would cor-
respond with the angle of reflection; the lid of the box is prevented
from opening too far. by means of straps or bars h, h, which hold it up
at right angles from the bottom; the hinged flap which carries the eye
piece bar is also supported in a line parallel with the bottom of the
case (and therefore with the picture). When the lid of the case is
lifted up the eye piece bar at once rises into its proper position by the
force of an elastic strap or India-rubber spring, which is attached to it
at the part where it is connected with the lid of the box.
By the above arrangement I am enabled to get a complete stereo-
scope into a case about six inches long, three inches wide, and half an
inch thick; the case may be. made to open either like a book, the hinges
being at one side, or, by somewhat modifying the internal construction,
it may be made to open from the middle like a pair of folding doors,
the hinges in this case being at each end.
Fig. 8, is a cross section, and Fig. 9*, a longitudinal section of a

page_text: modification of the above. In this instance the flap g, is supported by
a central partition, which when the flap is lifted up at once springs
into its proper position by the elasticity of an India-rubber spring.
Fig. 10, is a cross section, and Fig. 11, a longitudinal section of
another modification of the above; the principal difference being in
the external form, by adopting which the collapsible eye pieces may be
dispensed with, as the case in this instance will not interfere with the
nose of the observer.
Another form of making the instrument consists in attaching the
eye pieces to two flaps, which have holes to look through made therein,
and are hinged to a central vertical partition, which is made moveable
in a vertical guide, so that it may be moved up or down for the purpose
of altering the focus when required.
An instrument constructed on this plan is shewn in section at
Figures 12 and 13; a, a, is the bottom, which is hinged to a central
partition b, b. In this instance the lenses are mounted in cells attached
to the upper ends of flexible tubes d, d, which are kept extended by
means of coiled or spiral springs when not compressed in the case or
box. The sides of the box which when the instrument is opened from
the bottom are hinged to the fixed central part b, b; and when the
hook or fastening which keeps them closed is undone, the pressure of
the coiled springs of the eye pieces will force the sides a, a, down into a
horizontal position, as shewn in Fig. 12, and at the same time cause the
hinged flaps g, g, to be raised into a horizontal position by India-rubber
or other elastic springs. It will now be understood that when the clasp
or fastening which keeps the sides of the case closed is unfastened, all
the several parts will at once spring into their proper position for
viewing the pictures, without any assistance from the observer.
order to adjust the eye pieces to the focus of the observer the central
bar k, to which the flaps g, g, are attached, may be drawn up and down
in the groove of the central partition b, b, as shewn in the drawing.
In
Fig. 14, is a longitudinal section, and Fig. 15, a transverse section of
a modification of the above; the principal difference being that the top
or lid opens in the same manner as in Figures 7, 8, and 9, and is
In order to steady the flap g,
not divided as in Figures 12 and 13.

page_text: which carries the eye pieces, I have adopted struts h, thereto, and also
an overhanging flap f, to shade over the glare of light.
These plans of constructing portable stereoscopes may be considerably
varied. I do not, therefore, intend to confine myself rigidly to the pre-
cise arrangements, which will be found to possess the same principle of
construction, although carried out in a somewhat different manner,
viz., that all the parts are connected together, and all fold up and
lie in one case, the top and bottom of which form part of the instru-
ment.
Having now described my improvements in stereoscopes, and the
best means with which I am at present acquainted for carrying the
same into effect, I claim, in conclusion,-
First, the application to stereoscopes of mirrors or reflectors placed
(above the picture or object to be viewed) at such an angle or inclina-
tion as will allow the object or picture to be reflected therein, so that it
may be seen by the observer in a natural or non-inverted position, as
above described.
Second, I claim the adaptation to the eye pieces of stereoscopes of a
sliding bar, perforated with holes in such a manner that each of the eye
pieces or apertures for the eyes may be alternately closed or obscured by
moving the sliding bar backwards or forwards, so that when two or
more pictures or representations of living or moving objects in different
attitudes or positions are presented to the eyes of the observer alter-
nately or in succession, an optical illusion, having the effect of
apparently moving objects, may be produced.
Third, I claim arranging around a central shaft or axle pictures or
representations of living or moving figures or objects shewn in different
attitudes and positions as above described, and so mounting them on
the said Shafts or axles that they may in succession be brought beneath
or in view of one or other of the eyes of the observer, so as to produce
pleasing optical illusions. I also claim connecting the sliding bar of
the eye pieces with the rotating shafts or axles on which the pictures
are mounted, so that both these parts may be made to act simul-
taneously.
1
Lastly, I claim the several plans herein shewn and described for so

page_text: constructing or arranging the several parts of stereoscopes that they
may be collapsed or folded together into a small space when not
in use. I claim particularly the plans shewn for causing either all or
certain of the parts of stereoscopes to. rise into their proper position
ready for use immediately the instrument is opened.
In witness whereof, I, the said Antoine Jean Francois Claudet,
have hereunto set my hand and seal, the Twenty-third day of
September, in the year of our Lord One thousand eight
hundred and fifty-three.
A. CLAUDET. (L.S.)