BRAZENET PANORAMIO APPARATIES
Year: 1864

page_text: LETTERS PATENT to François Auguste Chevallier, Physician, of 2, Rue
Sainte Appoline, Paris, Empire of France, for the Invention of "Iи.
BRAZENET PANORAMIO APPARATIES"
Sealed the 9th June 1865, and dated the 16th December 1864.
PROVISIONAL SPECIFICATION left by the said François Auguste Chevallier,
at the Office of the Commissioners of Patents, with his Petition, on
the 16th December 1864.
I, FRANÇOIS AUGUSTE CHEVALLIER, Physician, of 2, Rue Sainte Appoline,
Paris, Empire of France, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PANORAMIC APPARATUS," to be as follows:-
My improvements essentially consist in rendering immovable the sensitive
surface placed horizontally under the object glass which there represents all
the surrounding objects, embracing this surface either successively in successive
sectors or all at once, whatever may be the mechanical and optical means
which give this result, and whatever may be the operating method employed
to obtain it.
The kind of instrument which forms the subject of the present Invention
I call a "horizontal photographic plane table";" the object glass is in this

page_text: instrument either fixed to the top of the centre of the sensitive surface, or it
extends circularly on the middle part of the radius of this surface. In the
first case the impression is made simultaneously on the whole surface, in the
second it is made successively by sectors fixed or not, and by a continuous
movement; thus the sensitive surfaces may be of different materials and of
any shape, so may also the forin of the horizontal photographic plane table
be varied indefinitely; the instrument then has a sensitive surface immovable
and horizontal either as the object glass revolves above it independently of the
dark chamber, or by an optical combination the compass of the horizon is
photographed by means of three elements constituting the instrument
being immovable, viz., the dark chamber, the sensitive surface, and the
optical.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said François Auguste Chevallier, in the Great Seal Patent Office
on the 16th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANÇOIS
AUGUSTE CHEVALLIER, Physician, of 2, Rue Sante Appoline, Paris, Empire of
France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said François Auguste Chevallier, Her special licence that I, the said François
Auguste Chevallier, my executors, administrators, and assigns, or such others
as I, the said François Auguste Chevallier, 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 PANORAMIC APPARATUS," upon the condition
(amongst others) that I; the said François Auguste Chevallier, 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,

page_text: 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 François Auguste Chevallier, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawings hereto annexed,
and to the figures and letters marked thereon, that is to say :-
.
My improved apparatus enable me to obtain photographs which directly-
give to a fixed point previously determined the angle that the vertical points
make between them passing through the fixed point and the different points
visible from this fixed point; thus by means of two proofs or impressions
taken from two stations, the distance of which is known, the visible points of
the two stations can at once be ascertained because a triangle is fixed when
a side and the two adjacent angles are known, moreover from it with a suffi-
cient number of impressions the plan of the ground whatever its extent can
be taken. By means of a slight modification I can also obtain photographs
giving directly the angles of altitude of the different points visible from the
fixed or station point when these levels are above or below the horizontal
level passing through the fixed point; the apparatus then enables me to
determine the height or level of these points when their position is found in
relation to the fixed point. In a word the apparatus enables me to erect a
marked and levelled surface. I will first describe the apparatus for producing
the surfaces; it is a photographic apparatus of peculiar construction, composed
of four distinct principal parts.
First, the optical system, its support, and the dark chamber, properly so
called.
Second, the frame containing the glass or the sensitive surface to receive
the photographic impression.
Third, an appliance for maintaining the apparatus in a perfectly horizontal
position.
Fourth, the apparatus annexed and its accessories.
The optical system comprises a combination of a prism and lens identical
to that employed by "Porta," that is a triangular rectangular prism, the
right angle faces of which are one horizontal and the other vertical, the hypo-
thenuse being tinned, the images which are received on the vertical face of
this prism are reflected in a horizontal plane, and the lens, the axis of which
is vertical, acts as in all dark chambers to give greater intensity to the image.

page_text: The whole of this system is contained in a tube carried by a horizontal plate
having a discontinuous or continuous motion about a vertical axis; this axis
is consequently parallel to the axis of the lens, moreover the edges of the
prism are perpendicular with the plane passing through the axis of rotation
and through the optical axis in such manner that all the points which are in
the vertical plane passing through the axis of rotation and through the optical
axis are represented on the horizontal plane, corresponding with the setting
point of the optical system according to the ray traced on this plan, and
passing through the axis of rotation and through the projection of the optical
axis. Reciprocally if for a determined position of the prism the ray passing
through the axis of rotation and through the projection of the optical axis is
led on the horizontal plane, it is certain that all the points of the image
meeting in this ray correspond with the points situated in the vertical plane,
passing through the axis of rotation and optical axis, it will thus be perceived
how by making from one given position several sights according to directions
determined by signals, which is possible owing to the rotation of which I have
spoken I can have graphically and photographically the angles that between
them make these different signals if I know for each sight the direction of
the ray passing through the axis of rotation and the optical axis; I will here-
after say how this indication is given by the apparatus itself. Thus as I have
said the tube containing the optical system is carried by a plate or support
which has several different arrangements. Now this plate is circular, and the
whole of its circumference rests on the anterior face of the dark chamber
which is arranged so as to receive it without admitting light, or it may form
part itself with the dark chamber which is free to move with it, and which in
this case is large enough to envelope it without touching it in any possible
position, the glass carrier frame which is fixed and immovable during the
whole duration of each operation. In the first case the vertical axis about
which the plate supporting the optical system is free to turn is not
material; it is at the centre of this circular plate which is guided by the
groove made in the anterior face of the dark chamber. In the second case
the axis is material, it is cylindrical or conical so as to guide the motion of
the apparatus well, but for the rest any other arrangement may be adopted
which enables me to obtain the coherence of the axis of rotation at the same
..time that it maintains the optical axis at rest exactly parallel to this rotation
axis.
The support plate of the optical system in its rotation draws with it a
screen which leaves below the lens an opening of any required size which limits

page_text: the breadth of the image. This screen carries in the free opening a thread or
hair placed in the plane which passes through the rotation axis, and through the
optical axis. This hair then intercepts on the image which is obtained the
image of the meeting points through the plane in question, and being deter-
mined on the horizontal plane, the angular direction of these points on which
the image is made. A second hair, perpendicular to the first, in the same
plane, and passing through the optical axis, intercepts in a similar manner on
the obtained image the points of the horizon comprised in the plan of the
level passing through the point of meeting the optical axis of the lens with
the hypothenuse of the prism. This arrangement of the hairs crossing one
another which I apply to my apparatus is an essential part of it, although I
can dispense with either hair or both in certain cases. For example, when
the apparatus has a continuous motion, and when it is not desired to have the
plane level. The dark chamber, as the ordinary dark chambers, is moreover
arranged so as to receive the frame in which the sensitive glass is carried.
When the dark chamber is fixed, the arrangement of the frame and the
arrangement of the dark chamber are those of frames usually employed. In
the case where the dark chamber is movable, it is simply arranged so that the
frame may be introduced inside, and fixed on a support which forms a pro-
longation of the axis of rotation. The important point is that the frame, or
rather the sensitive surface which it contaius, be in a position perfectly per-
pendicular to the optical axis of the lens, whatever may be the means em-
ployed to obtain this perpendicularity. Byanarrangement of screws or blocks
I am enabled to regulate the distance between the sensitive surface and the
support plate of the optical system, and in order that the hairs giving the
plane of the level and the hair of direction, the vertical plane passing through
the axis of rotation, and the optical axis may impress their image on the
sensitive plate with a complete clearness.
It will be seen that the exactness of the operations depends upon the per-
fect verticability of the optical axis and the perfect horizontability of the plane
receiving the image. To obtain this result, and to regulate the position of the
instrument, a screw-adjusting arrangement analogous to that employed in
apparatus of precision is carried by the support either from the axis of rotation,
when the dark chamber is movable, or by the support of the dark chamber
itself, when it is fixed. Air levels placed at different parts of the apparatus
enable me to verify the accuracy of the adjustment.
The accessory apparatus fixed on the principal apparatus are; first, a compass
for setting the position of the impressions; second, a telescope or an alhidade,

page_text: which enables me to examine successively the points, the relative position of
which are required, that is, in order that the hair of the telescope and the hairs
of the pinules correspond with the plane passing through the axis of rotation
and the optical axis of the lens; third, a spring or weight motor, which imparts
to the plate a continuous rotary motion. This continuous motion enables me
to obtain panoramic photographs, which instead of giving the position of a
number of limited parts, those only on which the sights have been made, give
the position of all the visible points from the station point. But to obtain
panoramic views, the screen which limits the breadth of the image is modified.
The free opening of this screen below the lens is reduced to a very strait slot,
which only allows the luminous rays comprised in the vertical plane passing
through the axis of rotation and the optical axis to reach the sensitive surface
in such manner that at each instant the only points comprised in the plane
thus determined are those of which the image is produced on the plan, and it
will be perceived that by the continuous movement an image is obtained
which will give the position of all the parts successively seen by the prism;
but this image deforms the object, all the vertical lines in nature converge
towards the centre of the image, while the horizontal lines are described by
curves, the forms of which vary.
To obtain mathematical exactness it is necessary that the slot be
mathematically strait, but that is impossible to materially realise. I am well
contented with the slot a millimetre wide for an image of ten to fifteen
centimetres, because as is shown, there is not sensible deformation from the
lens in an angle of ten degrees.
Such are, as a whole, the principal arrangements intended to produce plans,
but it must be understood that these arrangements are not absolute, and that
they may vary provided the principles laid down are adhered to. For example,
the prism of the optical system might be placed in such manner that the tops
of monuments, houses, trees, would be represented towards the centre of the
sensitive plate, or towards the circumference. The tube containing the optical
system would be placed above or below the dark chamber, the surface of the
sensitive collodion could be impressed directly or through the glass which
supports it, so as to have matrices from which right or inverse positive proofs can
be taken to produce plans from the photographic operations carried on on the
earth. The lens may be replaced by a system of combined lenses; the prism
may be replaced by an inclined mirror at forty-five degrees; the glasses may
be square, rectangular, or circular. An arrangement permits of marking
mechanically the centre or axis of rotation, or this centre will be indicated by

page_text: the convergence of the vertical lines. The dark chamber can be arranged in
any desired manner, and as there is only a part of these different arrangements
which are indicated on the Drawings hereto annexed, I intend to reserve to
myself the right of applying all these arrangements to the apparatus.
I have said that by means of a slight modification the apparatus applicable
to raising the plan is equally applicable to the determination of angles of alti-
tude. In fact, suppose the axis of rotation become horizontal as well as the
optical axis, and that the sensitive surface be vertical. If I now turn the
apparatus on its axis of horizontal rotation, all that I have said relative to
the image given by the vertical lines in the primitive position applys in the
second position to the image of the points situated in a plane passing through
the axis of rotation and through the optical axis of the lens; that is, that all
the points situated in this plane join according to the ray, and so all that I
have said of the apparatus with a vertical rotating axis applies to the apparatus
having a horizontal rotating axis.
The accompanying Drawings represent different views of apparatus com-
prising the new elements indicated above.
Figure 1 is a horizontal view in plan; Figure 2 is a section through the
middle of the apparatus; and Figure 3 is a vertical view or an elevation of
the same apparatus with the dark chamber and sensitive surface fixed, the
optical being removed.
Description of the instrument shown at Fig. 1, 2, and 3. A, dark chamber;
C,frame of the sensitive surface; C', rack for opening and closing the converg-
ing shutters moved by the pinion 1,(for the details of the converging shutters
and the pinion 1, see the description of Figure 8); D, disc supporting the
optic, the level N, the shutters etc.; this disc is in gear with a tangent screw;
G,glass or other suitable sensatised surface made of any form or shape as well
as its frame C which holds it; L, telescope, which may be replaced by an
alhidade with pinules; M, mounting of the object glass, which may be of the
form in, or of any other form; N, level; O, lens; P, prism. The combination
of a prism or lens or of a lenticular prism alone may be used; I,shutter broken
from the frame of the sensatised surface; V, vernier şerving to indicate the
numeral amplitude of the azimuth angles on the circumference of the disc D;
1, pinion of the converging shutters; a, rod with pinions or other mechanical
means for opening or closing the shutter of the frame C; T, tube for setting.
Figure 4 is a plan, Figure 5 a section, and Figure 6 an elevation of an
apparatus with a fixed sensatised surface, dark chamber and optic being
movable.

page_text: A, dark chamber, round or polygonal; B, compass; C, frame fixed to the
sensatised surface; C', rack of the converging shutters; D, divided circle on
which the angles of rotation are bedded; G, sensatised surface; I, vernier
indicating the angle and opening of the converging shutters; L, dipping
telescope; M, mounting of the object glass or optic susceptible of a conical
form m, m, or any other form; M', crank of the tangent screw V'; N, level;
O, lens; P, prism. The combination of a prism and lens or a lenticular
prism may be employed, etc.; P', aperture made at top or bottom for the
introduction 6, 7, of the frame C; R, shutter of the frame C of the
sensatised surface; S, fixed centre supporting the frame C, and keeping
it immovable; S movable centre supporting and drawingin its movement of
rotation about the centre; S the dark chamber, the object glass, the com-
pass, etc. etc. This movement is obtained for the continuous impressions
by the tangent screw V', and for the impressions with fixed sectors; I
can throw out of gear the tangent screw Vand move the apparatus by
hand; T tube for setting; it is with or without glasses, simple or colored,
and provided with an obturator; V, converging shutters; V, tangent screw
producing the rotation of the movable centre S'; V", vernier, indicating the
angle of rotation on the divided surface I); v, screws of the fixed centre S; ",
divided rule for showing the angle of the aperture of the converging shutters
(see the converging shutters in the description of Fig. 8), 1, pinion of the
converging shutters; Figure 7 represents a view of the converging shutters.
DESCRIPTION OF FIGURE 7.
B, sin all rods sliding the length of the frame, giving the motions of the
shutters by the buttons b, which slide in their groove in proportion to the
extent of their opening and closing. The division indicating the angle of the
opening of each shutter is on each side of the frame, and the buttons b', which
serve to open and close the shutters, serve at the same time as verniers; C, frame
of the shutters; C., centre to pinion, with a compass head; O, groove of the
frame in which the shutters enter in proportion to their opening; V,converging
shutters; b, burtous serving to conduct the small rods for the movements of
the shutters, and as indicators or verniers for the angle of the opening.
Figures 8 and 9 are two views of the goniometric frame. This frame is
composed of the hollow frames C and the converging shutters V and V.
These shutters may represent a triangle V or V', they are driven by the

page_text: rods B', as in Figure 7, having the same indicators and divided scales
Figure 7, but they have over the shutters of Figure 7, the centre of which
is as a bead of compass, the advantage of giving the summet of the triangle by
means of a system of half circles, the opposite cuts of which 1', 2, 3',
(Figure 9) the half circles 1', 1' are fixed to the two interior faces of the
frame, by their straitest part; they slide in the opening left free between the
half circles 2', 2, 3', 3', fixed to the two opposite faces of the doors by their
largest part. They may have the form represented at A, A', or each the
three-quarters of the circumference, and slide one on the other, being held in
a circular groove, and driven by the rod B; the two ends of the crank or rod
sliding in the groove b are driven by the pinion 1 by means of the rack C', C',
and determine the opening or the closing of the shutters, the augle is then on
the scale R.
Figure 10 is a plan, Figure 11 a section, Figure 12 an elevation
of an apparatus for obtaining circular, radial,and zenithal pictures by means of
an ordinary dark chamber drawing the object glass in its movement of
rotation, and leaving the sensatised surface immoveable.
its
DESCRIPTION OF FIGURES 10, 11, AND 12.
A, dark chamber; A', the same reversed on the frame P,for ordinary views
and portraits (Figure 11); C,sensatised frame, free to slide as a drawer under
the plate P; C', rack fixed on the plate P, and intended to make the dark
chamber advance or recede by means of pinion 1, for lengthening or shortening
ray of rotation; G,sensatised surface; H', opening formed in the plate P,and
calculated by taking H for the base of the triangle of which pinion I is the
summet. This opening allows the light to pass in order to impression the
sensitive surface which contains the frame with drawer C. This frame may
have a double face or a double length, it is forced into 1', 1', for a first image,
and into 2, 2' for a second image; and so on; the frame is returned for the
two last images; care must be taken to close the shutters on the surfaces im-
pressed after such operation. L,dipping telescope; M, mounting of the vision
or object glass; O, lens and its mounting; P, plate on which the apparatus
moves; P¹, mounting of the prism; R,broken shutter of the movable frame;
S,fixed centre mounted on the tripod; S',movable centre supporting the plate
P,and capable of being displaced to set the apparatus at will; V', taugent
screw for producing the circular motion of the dark chamber to which it is fixed
at X; V", shutters quarter of a circle (more or less) depending (to hinges
or otherwise) from the bottom of the dark chamber and intended to veil the

page_text: sensitive surface during the rotation of the apparatus. X, point of attaching
the tangent screw to the dark chamber; Y,throat-split for the tangent-screw;
V' a rack for driving the broken shutter R; (it can have another form); c,slides
of the frame; m,crank of the tangent screw; q,plate of the bottom of the dark
chamber, supporting the pinion 1, intended to displace the dark chamber by
means of the rack C' and opening at V by the converging shutters or the
triangular interior which replaces them; 1', spring for fixing the position of
the frame of the sensitive surface in the slides C; 1, pinion of the rack C¹ ;
2, pressure screw for fixing the position of the apparatus.
Figure 13 is a section of the lenticular prism, giving at one time the com-
pass of the horizon or view,and being capable of replacing the three elements,
the optic, dark chamber, and immovable sensatised surface.
Figure 14 is a section of a metallic or other prism (with a cap) in-
tended for the same operation, and giving results similar to the lenticular
prism.
Figure 15 is an apparatus comprising a dark chamber, an optic, and a
seusatised immovable surface, and giving the compass of the horizon at a
single stroke.
DESCRIPTION OF FIGURE 15.
A, dark chamber; frame C; broken shutter R, etc. etc., described with,
reference to Figures 1, 2, and 3. B,cone carrying the prism and its draught ;
b, the action for setting the focus; V, set screw for working the draught b.;
G, cover of the object glass; O, lens (which is not used when a lenticular
prism is employed); P, lenticular or other prism.
There is yet another improvement, and which consists in placing the part
containing the optic in a position opposite to that hitherto employed, that is
by putting it under instead of putting it above the frame containing the plate
of the sensatised glass. By this means I obtain the impression without its
being reversed, and by protecting it with a yellow glass I can follow the
impression of the image and direct the effects as desired.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim,-
First, the employment of a combination of prism, mirrors, or lens moving
on an axis, and giving on a plan sensitised to the light an image on which
can be measured, by means of a divided circle, or by any other means, the
angleswhich the signals make between them, or by means of which the angles.
are graphically traced.

page_text: Second, the employment of hairs indicating the direction of the verticaland
horizontal plans.
Third,giving to the apparatus a continuous or discontinuous motion, either
mechanically or by hand, as herein-before described.
Fourth, the construction and arrangement of panoramic apparatus, together
with any mere modifications thereof substantially, as herein-before described
and illustrated in the accompanying Drawings.
In witness whereof, I, the said François Auguste Chevallier, have here-
unto set my hand and seal, this Tenth day of June, in the year of our
Lord One thousand eight hundred and sixty-five.
.F. A. CHEVALLIER. (L.s.)