AN IMPROVED MICROSCOPE TO BE USED FOR EXHIBITING PHOTOGRAPHIC VIEWS AND PRO- DUCTIONS
Year: 1861

page_text: LETTERS PATENT to Réné Prudent Patrice Dagron, of Paris, in the
French Empire, Photographer, for the Invention of "AN IMPROVED
MICROSCOPE TO BE USED FOR EXHIBITING PHOTOGRAPHIC VIEWS AND PRO-
DUCTIONS."
"
Sealed the 18th March 1862, and dated the 19th September 1861.
PROVISIONAL SPECIFICATION left by the said Réné Prudent Patrice
Dagron at the Office of the Commissioners of Patents, with his Petition,
on the 19th September 1861.
I, RENÉ PRUDENT PATRICE DAGRON, of Paris, in the French Empire,
Photographer, do hereby declare the nature of the said Invention for "AN
IMPROVED MICROSCOPE TO BE USED FOR EXHIBITING PHOTOGRAPHIC VIEWS AND
PRODUCTIONS," to be as follows:-
This Invention is based upon certain parts of a former Invention for which
Letters Patent, bearing date the 28th March 1860, No. 801, were granted to
Aené Prudent Patrice Dagron. The present Invention consists, first, of a
double tubular image microscope, composed of two cylinders, at the bottom of
which are placed or fixed on each side two photographic microscopic images.
Secondly, of a tube joined to the two cylinders aforesaid, which serves to
connect them together, and also to keep them asunder. This tube can be
furnished with a partition to absorb the optic oblique rays. Thirdly, in placing

page_text: photographic microscopic proofs on glass, each joined by an achromatic lens;
the distance between the two should be such that the focus of the first lens
acts on the second image which is opposite thereto, and the focus of the second
lens acts on the first image, so that in looking either way the front image
appears enlarged by the ocular lens. A remarkable feature in this arrangement
is, that the image which is glued on to the optic lens does not obstruct the
view of the opposite or front image; or instead of making the microscope as
above stated, I propose to make a double image microscope entirely of glass.
This microscope is formed of three pieces of glass. The intermediate piece is
formed either plain, cylindrical, or otherwise, and receives the two images to
be viewed one at each end, the outer surface of each of the other two
pieces of glass is formed convex; these pieces are glued or otherwise affixed
to the plain surfaces which contain the images to be viewed, and these two
glasses or lens serve as ocular or object lenses, according to which is looked
through; or, instead of the foregoing arrangement, the microscope may be
composed of five pieces of glass, the three intermediato glasses being
cylindrical, with square or flat ends, the middle glass being considerably
longer than the outer ones. These glasses are each coupled with a lens or
end glass, which can be rendered achromatic with said glasses. I can, if
desired, dispense with the intermediate glasses, and employ a cylindrical piece
convex at each end; the images to be received would then be placed on each
end, and be protected from injury by covering same with glass, transparent
varnish, or other suitable substance or material.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Réné Prudent Patrice Dagron in the Great Seal Patent 2
Office on the 19th March 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RÉNÉ
PRUDENT PATRICE DAGRON, of Paris, in the French Empire, Photographer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Nineteenth day of September, in the year of our Lord
Ono thousand eight hundred and sixty-one, in the twenty-fifth year of Her
rgn, did, for Herself, Her heirs and successors, give and grant unto me, the
said Réné Prudent Patrice Dagron, Her special licence that I, the said
Réné Prudent Patrice Dagron, my executors, administrators, and assigns, or 3
such others as I, the said Réné Prudent Patrice Dagron, my executors,

page_text: 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 "AN IMPROVED MICROSCOPE TO BE USED FOR EXHIBITING
PHOTOGRAPHIC VIEWS AND PRODUCTIONS," upon the condition (amongst others)
that I, the said Réné Prudent Patrice Dagron, my executors or adminis-
trators, 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, 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 Réné Prudent Patrice Dagron, 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, that is to say:-
This Invention is based upon certain parts of a former Invention for which
Letters Patent, bearing date the 28th March 1860, No. 801, were granted to
Aené Prudent Patrice Dagron. The present Invention consists, first, of a
double tubular image microscope, composed of two cylinders, at the bottom of
which are placed or fixed on each side two photographic microscopic images.
Secondly, of a tube joined to the two cylinders aforesaid, which serves to
connect them together, and also to keep them asunder. This tube can be
furnished with a partition to absorb the optic oblique rays. Thirdly, in placing
photographic microscopic proofs on glass, each joined by an achromatic lens ;
the distance between the two should be such, that the focus of the first lens
acts on the second image which is opposite thereto, and the focus of the second
lens acts on the first image, so that in looking either way the front image
appears enlarged by the ocular lens. A remarkable feature in this arrange-
ment is, that the image which is glued on to the optic lens does not obstruct
the view of the opposite or front image; or, instead of making the microscope
as above stated, I propose to make a double image microscope entirely of
glass. This microscope is formed of three pieces of glass. The intermediate
piece is formed either plain, cylindrical, or otherwise, and receives the two
images to be viewed one at each end; the outer surface of each of the other
two pieces of glass is formed convex; these pieces are glued or otherwise
affixed to the plain surfaces which contain the images to be viewed, and these
two glasses or lenses serve as ocular or object lenses, according to which is
looked through; or, instead of the foregoing arrangement, the microscope may

page_text: he composed of five pieces of glass, the three intermediate glasses being
cylindrical, with square or flat ends, the middle glass being considerably longer
than the outer ones. These glasses are each coupled with a lens or end glass,
which can be rendered achromatic with said glasses. I can, if desired,
dispense with the intermediate glasses, and employ a cylindrical piece convex
at each end; the images to be viewed would then be placed on each end, and
be protected from injury by covering same with glass, transparent varnish, or
other suitable substance or material.
And in order to explain my said Invention as completely as possible, I now
proceed to describe the best means I am acquainted with for carrying the
same into practical effect, reference being had to the illustrative Sheet of
Drawings hereunto annexed, and to the numeral figures and letters of
reference marked thereon, as follows:-
DESCRIPTION OF THE DRAWINGS.
Figures 1, 2, 3, 4, 5, represent a double image tubular microscope, which
may be made of the following forms:-First, of exterior tubes or sockets, at
the bottom of which are placed on each side the two photographic microscopic
images to be viewed. Secondly, from an inside tube, enclosed by the two
aforesaid sockets, which serve to unite them together, and to keep them apart.
This tube can be furnished with a diaphgram to absorb the oblique visual rays.
Thirdly, photographic and microscopic images, which are coupled each with a
plano-convex achromatic lens; the separation of the two lenses is such, as
that the focus of the first lens is made on the second image, which is placed
opposite, and reciprocally, the focus of this second image is made on the first
image, so that in looking through either of said levers, the image can be
seen enlarged by an ocular lens. The image, glued or otherwise attached to
the ocular lens, does not impede the view of the image in front, which is not
perceived, and it is upon this optical phenomenon that my Invention is based.
Figure 1 is a vertical section of one form of microscope; Figure 2, a section
of the inner tube h.
At Figure 1, a and b are the two lenses, placed at the two extremities of
the microscope in the two sockets c, d, which can be slided on the tube h, as
desired; e and are two flat cylindrical glasses, on which the photographic
images are affixed; g, g, openings at the extremities of the sockets and d;
h, the tube on which the two pieces c and d are placed; i, a small collar or
diaphgram formed in the interior of the tube h. The use of this collar i is to
arrest the luminous rays which are necessary for perfectly viewing the image.
The focus of the lens a, as denoted by red lines, is directed on to the image on

page_text: the glass f, and the focus of the lens 6 is directed on to the image on the
glass e. In using the lens a as an ocular, the image is seen placed on the
glass f magnified. The image placed on the glass e does not hinder in the
least the visual luminous rays, and vice versa. As regards the lens b, I can
dispense with the tube h, and unite and fasten by a screw the two sockets c
and d, so as to form one single tubular part m, as at Figures 3 and 4, and
instead of placing the glasses e and f against the lenses a and b, I can connect
these said lenses together at the middle of the tube m, as at Figure 3.
Figure 4 shews a method of fixing the two images on a single glass n. In
Figures 1 and 2, the red lines indicate the focus of each lens a and b, when an
intermediate glass or glasses are not used, and the blue lines at Figures 3
and 4 show the focus of the lenses when intermediate glasses which carry the
image are used. Lastly, Figure 5 shows the instrument drawn to its true
proportions.
Figures 6, 7, 8, 9, and 10, represent double image microscope made all of
glass. Figure 6 shews a double image microscope composed of three pieces
of glass. The intermediate piece j is of solid glass of a cylindrical form. The
two images are attached at k, k', then the two convex glasses or lenses 1, 11,
are fastened or adapted to the plain or flat ends of which carry the images to
be viewed, and these two glasses or lenses 1, l, serve as ocular lenses when
looking through either of them. Figure 7 shows the microscope composed of
5 pieces. The glass is shorter than in the preceding disposal; the image
rests in the intermediate glasses e and f, as at x, x. These glasses e and f
are each joined with a lens, which may be achromatized with said glasses.
Figures 8 and 9 show the images to be viewed placed in the middle of two solid
glasses j, j, formed with convex ends. In the arrangement exhibited, Figures
4 and 5, the two glasses bearing the images to be viewed may be differently
employed, as at e and f (Figure 3), or the two images may be united on a
single intermediate glass, as at n (Figure 8), or fasten the images directly on
each piece, as at j, j, Figure 9. Lastly, Figure 10 shews the instrument
reduced to the real proportions, and ready to be placed in a jewel, or mounted
on a penholder, fan, or any other article of use. I can, if desired, dispense with
any kind of lens or intermediate glasses by making the glass solid throughout
its length, and the ends thereof of a convex form, and affix the image to be
viewed thereto. In this case the images may be protected from injury by
covering them with glass, or varnish, or any other suitable material.
Having now fully described and set forth the nature and object of my said
Invention, of "An Improved Microscope to be used for Exhibiting Photo-
graphic Views and Productions," together with the best means I am acquainted

page_text: with for carrying the same into practical effect, I hereby declare my Inven-
tion to consist in and I claim, constructing a microscope as above described
with reference to the several Figures of the accompanying Drawing as
constituting my Invention.
In witness whereof, I, the said Réné Prudent Patrice Dagron, have 5
hereunto set my hand and seal, this Eighth day of March, in the year
of our Lord One thousand eight hundred and sixty-two.
R. P. P. DAGRON. (L.S.)