Improvements in Apparatus for Facilitating the Microscopical Examination of Photographic Pictures, Maps, and other Objects.
Year: 1889

page_text: Date of Application, 13th Nov., 1889
Complete Specification Left, 24th May, 1890-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Facilitating the Microscopical
Examination of Photographic Pictures, Maps, and other Objects.
I, HENRY DUNCAN, of 16, Tokenhouse Yard, in the City of London, Stockbroker
do hereby declare the nature of this invention to be as follows :-
My invention relates to apparatus for facilitating the microscopical examination of
photographic pictures, maps and documents, and other small or microscopic objects.
My said invention is chiefly designed to afford the means whereby photographic
miniatures of maps or the like, which while occupying a comparatively small space,
correspond to a very large area, can be easily examined.
My said invention is particularly serviceable to bicyclists and tourists, and for
military and other purposes where ordinary maps would be objectionable by reason of
their bulk or by reason of the difficulty of using them particularly in stormy or wet
weather.
An important feature of my said invention is the provision of suitable means
whereby the microscope may be readily adjusted relatively to the map or other object,
so that any desired section of the said map or other object can be brought into the
field of the said microscope. By this means, with a comparatively small lens, it is
possible to examine objects which as a whole occupy an aroa very much larger than
the field of such lens.. "For example any desired part of a small scale map showing
an area of say three or four hundred square miles may be examined by adjusting the
microscope as required.
In making a portable apparatus according to my said invention, I arrange the lens
or lenses in a suitable tube or holder capable of sliding in a disc or other piece fitted
to rotate in or upon the frame of the map, picture or the like. Or 1 provide other
suitable means for adjusting the lens or lenses in any direction relatively to the said
map, picture or the like for the purpose above specified.
The tube carrying the lens or lenses is sometimes arranged to slide into and out of
the main portion of the apparatus.
The map or the like is preferably photographed on a greatly reduced scale on a
disc of glass which will fit into a suitable case or holder provided with a removable
cover and is protected with another disc of glass secured to the first disc in any
convenient manner. 1 sometimes so construct these discs as to prevent rotation of
the same in their case or holder, for example I form notches in them to engage
with a stud or projection in the holder. I can, if desired, provide the apparatus
with any desired number of interchangeable maps, pictures or the like mounted in
this manner.
This
A stud or projection is sometimes provided on the said frame to facilitate_the
use of the apparatus by indicating which is the top or north of the map.
stud or projection moreover engages with a notch in the cover of the holder for
the map or the like and prevents rotation of the said cover relatively to the said
holder.
In some cases I make the map or other object adjustable while keeping the lens
fixed, so that different parts of the said map or the like can be brought into the
field of the said lens, or both the lens and the object may be made adjustable
relatively to each other.
Dated th: 10th d
L. 1000

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Facilitating the Microscopical
Examination of Photographic Pictures, Maps, and other Objects.
I, HENRY DUNCAN of 16 Tokenhouse Yard in the City of London, Stock Broker,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
My invention relates to apparatus for facilitating the microscopical examination of
photographic pictures, maps and documents and other small or microscopic objects.
My said invention is chiefly designed to afford the means whereby reduced
photographs of maps or the like which, while occupying a comparatively small space,
correspond to a very large area, can be examined with great facility.
My improved apparatus is, by reason of its compactness and portability, very
serviceable to bicyclists and tourists and for military and other purposes, where
ordinary maps would be inconvenient or objectionable by reason of their bulk or by
reason of the difficulty of using them, especially in stormy or wet weather.
An important feature of my said invention is the provision of suitable means
whereby the microscope may be readily adjusted so as to include in its field any
desired portion of the said map or other object. By this means, with a comparatively
small lens, it is possible to examine objects which, as a whole, occupy an area very
much larger than the field of such lens. For example any part of a small scale map
showing an area of say seven or eight hundred square miles may be examined by
adjusting the microscope as required, relatively to the said map. Moreover after tho
adjustment of the lens as required, the apparatus can, if desired, be held in one hand
during the examination of the map, the other hand being left free for other purposes.
In constructing an apparatus according to my said invention, 1 arrange the lens or
lenses in a suitable tube or holder and I provide suitable means for adjusting the lens
or lenses in any direction relatively to the map, picture or the like as hereinafter
described.
In the accompanying drawing, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a front elevation, and
Figure 2 a side elevation showing my improvements applied to a miniature map.
Figure 3 is a front elevation, illustrating a slight modification of my said
invention.
A, A are sheets of glass, plain or bound in a light metal frame, with a map between
them. B is a frame, clip or holder for the glass. This frame or holder may, if
desired, extend entirely around the glass. I prefer, bowever, to make it, as shown,
in the form of a clip or clamp, so that the glass can be very readily removed from or
replaced in it. C is the lens, which is secured in a tube C₁ fitted to slide in a socket
'or holder D provided with lugs or projections D'. Through these lugs are passed
arms or guides E¹ fixed in a cross-piece E which is pivoted at E to the clip or
holder B. This clip or bolder comprises a plate B' in which the pivot E² is fixed and
which bears against one side of the glass. This plate is provided with a screw B
having a thumb-nut B³, or a suitable nut adapted to be turned by a key or otherwise
in cases where the projections of the thumb nut are objectionable. A second plate B
bears against the other side of the glass and is provided with a hole through which
the screw B² is passed. The said thumb-nut B³, when tightened, presses the plate B
towards the plate B', thus clamping the glass firmly between the said plates. The
'plute B is provided with guiding pins or projections Bs, which fit into holes or
notches in the plate B' and serve to retain the said plates in their proper relative
position and facilitate the application of the clip or holder to the glass.
By turning the guides E¹, which may, in some cases, be connected together at
their outer extremities, about the pivot E³ and moving the lens-holder D in one or

page_text: the other direction along the said guides, as required, the lens C may be freely
moved in any direction over the map or other object to be examined, and the field
of the lens thus caused to include any desired part of the said map or other object.
To prevent fracture of the glass by the pressure of the plates B¹ and B' thereon, 1
sometimes attach a piece of leather or other suitable material to the inner surface of
the plate B and place upon the plate B one or more rings B of india-rubber or
other soft clastic or suitable material. In other cases, I provide one or more
cushions or pads on the glass. The cushion or pad may be of one piece and may
extend around that part of the edge of the glass to which it is desired to attach the
clip. It is formed preferably of leather, india-rubber, gutta-percha or similar
material and is secured to the glass in any suitable manner. By arranging the said
cushion or pad to extend over the edge of the glass, I provide very effectually for
Moreover
preventing fracture of the glass in applying the clip or holder thereto.
by attaching the said cushions or pads to the glass instead of to the clip or holder,
I provide for facilitating the application of the said clip or holder to the glass. In
some instances I provide the glass with a metal frame a extending all around it as
shown in Figure 3, and having widened portions a¹ which serve the same purpose
as the cushions or pads.
Another means of attaching the glass to the frame is to perforate the glass and
pass a screw through the samo to connect the two plates B1, B4, suitable cushions
or pads being provided between the glass and the plate to prevent fracture of
the glass.
To diminish the bulk of the apparatus as much as possible, 1 sometimes provide a
tube for the lens or lenses made up of several small sections adapted to slide one
within the other telescopically so that the whole may be closed together and will then
occupy but a small space. 1 may, however, arrange the said lens in any other
suitable manner for the purpose of my said invention.
The map is preferably photographed upon one sheet or plate of glass or other
transparent material and a second sheet or plate of glass or other transparent
material is then secured over the map to protect the same.
1 find it advantageous
to have the outer side of one of these two sheets of glass, proferably that at the
back of the map, slightly frosted or ground so that reference marks can with facility
be made thereon by means of a pencil or other suitable instrument.
It is obvious however that, if desired, the reduced map or the like may, for the
purpose of my invention, be photographed or otherwise produced upon opaque or
semi-opaque substances, instead of upon glass or other transparent material.
A pointer F is sometimes provided which projects inward from the wall of the
lens-holder D to, or approximately to the centre of the field of the lens. When it
is desired to indicate the position of some place on the map by a special mark, this
operation is greatly facilitated by the use of the said pointer, which can be adjusted
so that its point coincides with the spot to be marked, and which, by reason of its
being visible through the slightly ground glass, will enable the mark to be made
thereon at the spot indicated by the pointer after the microscopo has been removed
from the eye.
This pointer is sometimes provided with notches disposed at intervals along the
edge of the same and the point on the map may, if desired, be marked by reference
to these notches.
In cases where the pointer is not used, I mark the map by simply holding the same
to the light, as in examining the map, and indicating the position by a pencil-mark or
otherwise on the frosted glass at the rear side thereof.
I sometimes secure in a suitable socket or recess in the frame or clip B, for
instance in the plate B' thereof, a small compass whereby the bearing of any place
may be readily ascertained.
To facilitate reference and to assist in finding places on the map, a series of
numbers are marked along one edge thereof and a series of letters along another
edge thereof at right angles to the first, and an index to the more important places

page_text: on the map, and referring to the said numbers and letters, is printed or otherwise
marked in microscopic characters on the glass in a marginal space thereon.
I sometimes also provide in such marginal space in microscopic type or characters
the directions for the use of the map or other information likely to be of service.
The apparatus shown in the drawing has the great advantage that it is easily
portable and very compact.
It is evident that several different maps can be carried in a suitable case and used
as required in my improved apparatus. The apparatus is, moreover, applicable for
the examination of portraits, views or the like, several of which may be photographed
on one sheet of glass or other material.
I can, if desired, mako the clip with a spring instead of with a screw for fastening
it on the glass. Moreover, instead of the clip, I can use a frame or holder extending
entirely around the glass and having the lens-holder fitted to slide in suitable
guides therein, the said guides being capable of angular movement or rotation
relatively thereto, or being capable of movement in a direction at right angles to that
of the lens-holder.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I wish it understood that
I claim -
First. An apparatus for facilitating the microscopical examination of photographic
maps and other objects, comprising a frame, clip or holder for the map or other
object, and a microscope or inagnifier arranged to slide to and fro in or upon
guides which are secured to the said frame, clip or holder and which are capable of
angular or other movement relatively to the map or the like, substantially as herein-
before described for the purpose specified.
Second. The combination, with one or more photographs on a sheet of glass or
other suitable material, of a frame or clip for supporting the same, and a lens or
lenses secured in a holder which is adapted to slide between guides pivoted to the
said frame or clip, substantially as described.
Third. Sheets or plates of glass or other material having between them a
photograph of a map, and one of which is frosted or ground or otherwise prepared
on its outer side, as, and for the purpose, above specified.
Fourth. The clip or holder comprising the clamping plates, the guiding pins or
studs, and a screw or other suitable device for pressing the said plates together (with
or without the compass secured in one of the said plates), substantially as, and for the
purposes, set forth."
Fifth. The combination, with the adjustable lens-holder, of a hand or pointer for
facilitating the marking of places on the map, substantially as described.
Sixth. A photograph of a map or the like on glass or other material (with or
without a frame) and provided with one or more cushions, puds, or the like for
protecting the said glass or other material, substantially as, and for the purposos,
set forth.
Seventh. The improved apparatus constructed substantially as described with
reference to the accompanying drawing for the purposes specified.
Dated this 23rd day of May 1890
HENRY DUNCAN.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.