IMPROVE- MENTS IN OPERA AND FIELD GLASSES AND GLASSES OF A SIMILAR CHARACTER FOR RENDERING THEM APPLICABLE AS PHOTOGRAPHIC APPARATUS, AND IN APPLIANCES EMPLOYED IN COMBINATION THEREWITH
Year: 1881

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN OPERA AND FIELD GLASSES AND GLASSES OF A SIMILAR CHARACTER
FOR RENDERING THEM APPLICABLE AS PHOTOGRAPHIC APPARATUS, AND IN
APPLIANCES EMPLOYED IN COMBINATION THEREWITH." A communication
from abroad by Alphonse Loiseau and Jean Baptiste Germeuil-Bonnaud,
both of Paris, France.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 23rd February 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN OPERA AND FIELD GLASSES AND
GLASSES OF A SIMILAR CHARACTER FOR RENDERING THEM APPLICABLE AS
PHOTOGRAPHIC APPARATUS, AND IN APPLIANCES EMPLOYED IN COMBINATION
THEREWITH." [A communication from abroad by Alphonse Loiseau and Jean
Baptiste Germeuil-Bonnaud, both of Paris, France.]
This Invention relates to improvements in opera and field glasses, and glasses of
a similar character for rendering them applicable as photographic apparatus, in
order that tourists and others, without requiring to carry photographic apparatus of
ordinary construction about with them, may readily take by means of such glasses
photographic pictures of any landscapes or objects they may desire.
It will be readily understood that the ocular end of an opera glass can serve to
receive a photographic objective, and that consequently by replacing the large
lenses by a frame for receiving a ground glass screen for focussing, and a frame
containing a sensitised glass for taking a negative, such glasses can be readily
converted into photographic apparatus, and that by using such sensitised glasses as
are employed for instantaneous photography; the operator may take instantaneous
impressions while simply holding the glass in his band, thus dispensing with a
stand for this purpose.

page_text: With double or twin glasses a sensitised plate may be applied to each barrel so
as to obtain stereoscopic views. Or the one barrel may be arranged to receive a
sensitised glass for photographing, and the other a ground glass screen for focussing,
so that the operator may hold the latter to the eye while he passes with the glass
over the landscape, in order to determine the exact view he wishes to take, and
then having arrived at such point, he may rapidly uncover and re-cover the
sensitised plate so as to obtain the photographic picture of such view.
The arrangement of the glasses may be variously modified for carrying out the
purposes of this Invention; thus according to one arrangement the rims, tubes, or
caps carrying the eye pieces and objectives of an ordinary opera, field, or marine
glass, are attached to the barrels by means of bayonet joints so that that they can
be readily detached, and there are provided, firstly, other caps provided with
objectives similar to those used in ordinary photographic apparatus, which can be
fixed in place of the eye pieces; secondly, a cap or rim having a ground glass
screen which is fitted in the place of one of the objectives; and, thirdly, a cap or
circular box which is fitted in the place of the other objective, and which contains
the sensitised plate. This plate is held in its place by a groove, and it is protected
from the light by a slide, which at the proper moment is drawn outwards through
a slit in the cap or box, the slit being closed automatically by a spring cover
during that time to prevent the entrance of light through it. The slide has a small
pin entering a groove in the cap, whereby it is held in place.
According to another arrangement the barrel is provided with an extension at
the objective end, which extension has an external screw thread, and upon this
thread is fitted a screw-ring loose upon a cylindrical piece having a stud fitting a
groove in the said screwed extension, so that by turning the said screw-ring on the
latter, the cylindrical piece will be slid to and fro thereon without rotating. To
the cylindrical piece is connected by means of a bayonet joint a small collapsible
camera obscura, such as is used for ordinary photographic apparatus, with provision
for inserting the focussing screen and the sensitised plate in the usual manner.
In this arrangement the ordinary objective lense of the opera glass may be used for
photographing.
According to another arrangement, instead of entirely removing the eye piece of
the glass and replacing it by a photographic objective, the latter is permanently
attached to the glass, and when this is to be used as an opera or field glass, a cap
having a double concave lense is simply fixed over the barrel of the objectives,
whereby these are rendered applicable as eye glasses.
According to another arrangement, applicable where the glasses are to be used
mainly for photographic purposes, and it is only occasionally desired to use them
as opera or field glasses, the one, barrel has, first, covering the photographic objective,
a hinged cover acted upon by a spring, so that it can be rapidly opened and closed
for photographing by pressing upon a tail of the cover with the finger and then
releasing it. To the other end of the same barrel is attached a rectangular box
like frame of larger dimensions than the barrel of the glass, so as to admit of taking
larger pictures, the frame being attached to the barrel by a cylindrical rim on the
front face of the former fitting over or into the latter. The one end of the box
like frame is open for the insertion of the sensitised glass, and it has a hinged cover
for closing it when the glass is introduced. In front of the sensitised glass is a dark
screen of flexible material, one end of which runs with eyes upon two guide bars,
on which are helical springs tending to keep the screen drawn over the sensitised
glass; the other end of the screen is led over a roller and connected to a sliding bar
at the rear side of the frame, which bar has a handle by which it, together with the
screen, can be drawn along, thereby withdrawing the screen from in front of the
sensitised glass against the action of the springs. The screen may be secured in
this position by hooking the said handle on to a stud on the frame. On again
releasing the handle the springs draw the screen rapidly over the sensitised glass
again.
The second barrel of the glass has fitted to its large end a cap having a central

page_text: tube with the focussing screen made of smaller diameter than the barrel, in order to
make room for the enlarged size of the box frame on the other barrel. The front
end of the second barrel is also provided with a photographic objective, fitted, like
that in the first barrel, in a sliding tube, which tubes are connected by a cross bar
and are moved in and out for focussing by a screw action in the same manner as
the eye pieces of the opera glass.
As before stated, when a sensitised surface such as bromised gelatine is used, that
allows of instantaneous photography, the instrument may be merely held in the
hand while operating, but in other cases a light portable tripod stand may be
provided, the upper end of which carries a double claw hinged to a stem on a
universal joint, and having a screw thread on which is a screwed cap projecting
over the lower ends of the claws, so that by first introducing the one barrel of the
before described apparatus between the claws and then screwing up the cap so
as to move the claws towards each other, the apparatus will be held firmly between
the claws.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
22nd August 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN OPERA AND FIELD GLASSES AND
GLASSES OF A SIMILAR CHARACTER FOR RENDERING THEM APPLICABLE AS
PHOTOGRAPHIC APPARATUS, AND IN APPLIANCES EMPLOYED IN COMBINATION
THEREWITH.' A communication from abroad by Alphonse Loiseau and Jean
Baptiste Germeuil-Bonnaud, both of Paris, France.
This Invention relates to improvements in opera and field glasses and glasses
of a similar character for rendering them applicable as photographic apparatus,
in order that tourists and others, without requiring to carry photographic apparatus
of ordinary construction about with them, may readily take by means of such
glasses photographic pictures of any landscapes or objects they may desire.
It will be readily understood that the ocular end of an opera glass can serve to
receive a photographic objective, and that consequently by replacing the large
lenses by a frame for receiving a ground glass screen for focussing, and a frame
containing a sensitised glass for taking a negative, such glasses can be readily con-
verted into photographic apparatus, and that by using such sensitised glasses as are
employed for instantaneous photography, the operator may take instantaneous
impressions while simply holding the glass in his hand, thus dispensing with a
stand for this purpose.
With double or twin glasses a sensitised plate may be applied to each barrel so
as to obtain stereoscopic views. Or the one barrel may be arranged to receive a
sensitised glass for photographing, and the other a ground glass screen for focussing,
so that the operator may hold the latter to the eye while he passes with the glass
over the landscape, in order to determine the exact view he wishes to take, and
then having arrived at such point he may rapidly uncover and recover the
sensitised plate so as to obtain the photographic picture of such view.
The arrangement of the glasses may be variously modified for carrying out the
purposes of this Invention; thus according to one arrangement the rims, tubes, or
caps carrying the eye pieces and objectives of an ordinary opera, field, or marine
glass are attached to the barrels by means of bayonet joints, so that they can be
readily detached, and there are provided, firstly, other caps provided with objectives
similar to those used in ordinary photographic apparatus, which can be fixed in place
of the eye pieces; secondly, a cap or rim having a ground glass screen, which is fitted
in the place of one of the objectives; and, thirdly, a cap or circular box, which is
fitted in the place of the other objective, and which contains the sensitised plate. This
plate is held in its place by a groove, and it is protected from the light by a slide
which at the proper moment is drawn outwards through a slit in the cap or box,
the slit being closed automatically by a spring cover during that time to prevent
the entrance of light through it. The slide has a small pin entering a groove
in the cap whereby it is held in place.
According to another arrangement the barrel is provided with an extension at
the objective end, which extension has an external screw thread, and upon this
thread is fitted a screw-ring loose upon a cylindrical piece, having a stud fitting a
groove in the said screwed extension, so that by turning the said screw-ring on the
latter the cylindrical piece will be slid to and fro thereon without rotating. To the
cylindrical piece is connected by means of a bayonet joint a small collapsible
camera obscura, such as is used for ordinary photographic apparatus, with provision
for inserting the focussing screen and the sensitised plate in the usual manner.
In

page_text: this arrangement the ordinary objective lens of the opera glass may be used for
photographing.
According to another arrangement, instead of entirely removing the eye piece of
the glass and replacing it by a photographic objective, the latter is permanently
attached to the glass, and when this is to be used as an opera or field glass a cap
having a double concave lens is simply fixed over the barrel of the objective,
whereby these are rendered applicable as eye glasses.
According to another arrangement, applicable where the glasses are to be used
mainly for photographic purposes, and it is only occasionally desired to use them as
opera or field 'glasses, the one barrel has, first, covering the photographic objective,
a hinged cover acted upon by a spring so that it can be rapidly opened and closed
for photographing by pressing upon a tail of the cover with the finger and then
releasing it. To the other end of the same barrel is attached a rectangular box-like
frame, of larger dimensions than the barrel of the glass, so as to admit of taking
larger pictures, the frame being attached to the barrel by a cylindrical rim on the
front face of the former fitting over or into the latter. The one end of the box-like
frame is open for the insertion of the sensitised glass, and it has a hinged cover for
closing it when the glass is introduced. In front of the sensitised glass is a dark
screen of flexible material, one end of which runs with eyes upon two guide bars,
on which are helical springs tending to keep the screen drawn over the sensitised
glass; the other end of the screen is led over a roller and connected to a sliding bar
at the rear side of the frame, which bar has a handle by which it, together with
the screen, can be drawn along, thereby withdrawing the screen from in front of
the sensitised glass against the action of the springs. The screen may be secured"
in this position by hooking the said handle on to a stud on the frame. On again
releasing the handle the springs draw the screen rapidly over the sensitised glass
again.
The second barrel of the glass has fitted to its large end a cap having a central tube
with the focussing screen made of smaller diameter than the barrel in order to make
room for the enlarged size of the box frame on the other barrel. The front end of
the second barrel is also provided with a photographic objective fitted like that in
the first barrel in a sliding tubes, which tubes are connected by a cross bar and
are moved in and out for focussing by a screw-action in the same manner as
the eye pieces of the opera glass.
As before stated, when a sensitised surface, such as bromised gelatine, is used that
allows of instantaneous photography, the instrument may be merely held in the
hand while operating, but in other cases a light portable tripod stand may be
provided, the upper end of which carries a double claw hinged to a stem on a
universal joint and having a screw thread on which is a screwed cap projecting
over the lower ends of the claws, so that by first introducing the one barrel of the
before described apparatus between the claws, and then screwing up the cap, so as
to move the claws towards each other the apparatus will be held firmly between
the claws.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a longitudinal section of a marine glass having the end caps
attached by bayonet joints so that they can be readily removed and replaced;
Fig. 2 shews the instrument in plan, partly in section, as it is adapted for
photography; Fig 3 is a front view of the front frame; Fig. 4 is a view of the
frame as seen from inside; and Fig. 5 is a transverse section of the frame.
A and A' are the two cases containing the lenses and their tubes B and B¹, which
are connected by the crosshead C to the adjusting spindle D and milled head E, by
which the lenses b, b, are focussed. The tube B is provided with a cover plate F,
of which Fig. 6 is a front view, provided with a spring to close it when it is
released. The other tube B¹ has a screwed cap G which is taken off at the time of
operating. At the front are fitted the photographic appliances. For A there is a
frame H to hold the sensitised plate, which is introduced through a slit in the upper

page_text: side of the frame. This slit is covered by a hinged cap h which is held by a snap
spring. To cover the plate from the light a screen J of black fabric is wound on a
small roller j, and has hinged to it a hook L. When the screen is withdrawn
during the photographic operation L is hooked over h, and on unhooking it a
spring acting on the roller j rapidly drags the screen in front of the plate. The
case A' is fronted by a frame M carrying a ground glass N which serves for
focussing. For instantaneous photography the screen may be arranged as shewn
in front view at Fig. 7, and in section at Fig. 8, and in back view at Fig. 9. A
plate P having through it a hole Q slides in guides X, X. When the plate is raised
it is kept up by an arm p on a vertical spindle R on which is fixed a vane S. For
dropping the plate P the operator blows on the vane and thus causes the spindle R
to turn partly round withdrawing the arm p from under the plate P which
thereupon falls. In some single glasses the telescope tube is made to screw into
the case for adjusting focuss, as shewn at Fig. 10. In this case the covering cap is
applied at U and the frame for the sensitised plate at V.
Having thus described the nature of the said Invention, and in what manner
the same is to be performed, as communicated to me by my foreign correspondents,
I claim,―
First. Combining with opera or field glasses and glasses of a similar character
suitable objectives, covers, glass frames, and screens, whereby they are adapted for
photographing, substantially as herein described.
Second. The arrangement whereby a double glass is applied to photography, the
one for focussing and the other for taking the image, as herein described with
reference to Figs. 1 to 6 inclusive.
Third. The arrangement of screen plate for instantaneous photography, as herein
described with reference to Figs. 7, 8, and 9.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Twenty second day of August, in the year of our
Lord One thousand eight hundred and eighty one,
CHAS. D. ABEL. (L.S.)