Improvements in Optical Devices for the Observation of Localities by Reflection.
Year: 1888

page_text: Improvements in Optical Devices for the Observation of Localities
by Reflection.
I, EDWARD AUGUSTUS TRAPP, of 304 Adelphi Street, in the City of Brooklyn, in
the County of Kings and State of New York, United States of America, Engineer, do
hereby declare the nature of my invention for "IMPROVEMENTS IN OPTICAL DEVICES
FOR THE OBSERVATION OF LOCALITIES BY REFLECTION," and in what manner the "
same is to be performed, to be particularly described and ascertained in and by the
following stateinent :-
The invention relates to Improvements in Optical Devices for the Observation of
Localities by Reflection, and it is based on the fundamental law of optics that the
angle of reflection from a plane mirror is equal to the angle of incidence.
The invention involves in part the use of a series of tubes extending at angles to
each other and provided at their meeting ends with reflectors arranged at equal angles
with the axial lines of the tubes, an inspection end, known as an eye-piece, being at
one end of the series of tubes, and a reflection end, known as an end piece being
at the opposite end of the series within range of the objects whose images are to be
reflected into the tube or tubes in position to be observed from the eye-piece ; said
invention consists, first, of a main tube having an eye piece at one end and a series of
branch tubes extending at angles therefrom, each of said branches terminating in end
pieces, and reflectors or mirrors being arranged at the joining ends of the tubes and
at equal angles with the axial lines of the tubes; second, of a main tube having a
telescope at one end and a reflector or reflectors at the other to receive the image of
the objects to be observed and sustain it in position to be observed by aid of the
telescope and third, of certain arrangements of the tubes and reflectors hereinafter
described, the tubes being at angles to each other and the reflectors at equal angles
with the axial lines of the tubes. In the employment of the invention the eye-piece
or inspection end will be provided with a lens of any suitable character, and the end
piece will preferably also be furnished with a lens.
Referring to the accompanying drawings, Figure 1 is a vertical section of a
building showing the application of the invention to the engine room and various
floors thereof, and adapted to enable a person on the top floor to observe what is
transpiring either in the engine room or on any one or more of the floors of the

page_text: ;
building Figure 2 a transverse section of a building illustrating the reflectors and
tubes, constituting a part of the invention, arranged along the halls of one floor;
Figure 3 a vertical longitudinal section of a reflector box containing two reflectors
and connected with vertical and horizontal branch pipes; Figure 4 an end view of
same Figure 5 an enlarged central vertical section of the reflectors and tubes com-
bined with means for illumination and adapted for use in submarine explorations, and
Figure 6 a view illustrating the practical application of same to such use.
In the drawings C designates the main tube having an eye piece D at one end and
a reflector box A at the other, said box having suitable covers W permitting the con-
venient introduction and inspection of the reflectors. The main tube C is provided at
desirable intervals with the branch tubes C, and mirrors or reflectors B. one of the
latter being supplied for each of said branch tubes and being secured on a hinged
back-plate B, as illustrated more clearly in Figure 5, in order that it may be turned
upward on the pivot a across the branch tube and thus leave an unobstructed view
through the main tube (to some other point, or be given a position across said main
tube and at equal angles with the axial lines of the tubes, thereby obstructing the
view below it and permitting the objects within range of the branch tube to be
reflected on it within the line of vision from the eye piece D. Various means for
moving the mirrors may be adopted, but I illustrate convenient appliances for this
purpose, the same consisting of the arm secured on the end of the pivot a and being
in connection with the weight d and rod or cord e, the weight. when the cord e is
released at the eye-piece D, serving to open the reflector from across the branch tube,
and the cord e affording means whereby the reflector may be again closed over the
branch tube when desired. In the main tube C will be formed what is substantially
a box, which will constitute a sufficient space for the reflectors B and afford a rest
for the upper end of same. As illustrated in Figure 1, one of the branch tubes C
with its reflector B. provided for each floor of the building, and the box A at the
lower end of the tube also contains a reflector B; when it is desired to inspect the
engine room from the eye-piece D all of the branch tube reflectors should be turned
upward against the branch tubes C in order to leave an unobstructed view to the
reflector box A, and enable the observer to clearly see the objects, within range of
the box, reflected upon its mirror. The box A will have a brauch tube C' extending
outward therefrom, and the objects within range will, as aforesaid, be reproduced to
view on the reflector within the box. If the engine room should be dark a reflector i
of ordinary form and a light should be provided, as shown in Figure 1, whereby to
illuminate the surrounding objects and ensure their reflection within the box A.
The branch tubes Cat the different floors of the building may lead to any
particular locality necessary to be inspected from time to time, and in Figure 2
I illustrate the branch tubes extending in opposite directions along the halls of the
floor at the points where the tubes are branched off at an angle, as for instance in
passing around a corner, it will be necessary to provide additional reflector boxes m, n,
in the use of which the objects will first be reflected into the box m, then into the
box 1, and finally from the box to the reflector B in the main tube where it will
be visible from the eye-piece D. The branch tubes may extend in any desired
direction and connected with any suitable number of branches and reflector boxes, the
mirrors or reflection surfaces in the boxes being arranged at equal angles with the
axial lines of the connecting tubes, the angles of reflection and angles of incidence
being equal.
The eye-piece D may have a convex or concave lens or a lens of any desirable
character, but where the main tube C is of considerable length and used in localities
ordinarily difficult of observation a telescope T will be supported in and constitute a
part of the eye-piece D, as shown more clearly in Figure 5, and which will enable
the observer to clearly see the objects reflected in the various boxes connected with
the main tube and to adjust the eye-piece at will without removing it and without
difficulty or loss of time.
The terminal ends of the branch tubes extending from the reflector boxes, may be
provided with lens of any desired character, and I prefer at such points to make

page_text: use of a double concave lens H, as shown enlarged in Figure 5, which will cause an
extended area to be reflected in reduced outline on the reflector plates within the
boxes, thereby enabling the observer at the eye-piece D to inspect considerable space
by means of a reflector of small size.
The reflector box, lettered A', shown in Figures 3 and 4, contains two mirrors or
reflector plates B, B. with branch tubes C extending laterally therefrom, and one
main tube C, as shown in full lines or two main tubes side by side, one for each
reflector plate, as indicated by dotted lines, the purpose being to enable the person
looking into the one main tube or the two parallel main tubes to observe the different
localities within range of the branch tubes extending in opposite directions. The
reflectors B, B, in the box A' will be connected with slides J, which will operate as
covers to snugly close the box and permit the reflectors to be introduced and
withdrawn at will.
In Figures 5 and 6 I illustrate the invention, as applied to submarine explorations,
and in these Figures the parts corresponding with like parts in the other Figures
bear similar reference letters and in operation are the same. The reflector box A
at the lower end of the main tube C, shown in Figures 5 and 6, contains two
mirrors B, B and the downwardly extending branch tube or end piece ( from said
box is provided with the double concave lens H, through which the surrounding
objects are reflected on the reflector plate B', and thence upon the reflector plate B,
where they will be visible from the eye-piece D. If the downwardly projecting
branch tube or end piece C" extended laterally from the box A, but one reflector B
would be necessary, as shown at the lower end of the main tube in Figure 1, but
where it is desired that objects directly below and surrounding the box A may be
brought to view at the end of a vertical tube, the box should have two reflectors.
In the use of the invention for submarine explorations a reflector and light will
be made use of, the light in this instance being produced preferably by incandescent
electric lamps, as shown; denoting the electric wire. The main tube when used
for submarine purposes may be made in sections for convenience and be projected
downward into the water from a boat, and the box A will preferably be supplied with
a lege to keep it elevated a suitable distance above the objects whose images are to
be reflected and observed from the eye-piece D.
I do not limit myself to the use of any particular style of lens in the eye-piece or
in the end piece, but recommend that a lens of some character be employed.
In the use of the invention it will be noted that a person may observe localities
or objects separated from him by either walls, ceilings, floors or other articles, which
would naturally obstruct the view under ordinary circumstances. The advantages of
being able to inspect the interior of banking rooms and similar places of business at
night by the janitor or watchman will suggest themselves, and the various uses to
which the invention may be put both for public service and private convenience do
not require to be specifically described.
The invention may, if desired, be employed in connection with a mirror, either
fixed or movable, which will reflect the images or localities into the branch tube in
position to be seen on the reflector in the main tube from the eye-piece. In instances
where objects removed from the direct range of the end piece are to be inspected,
it will be found convenient to have a mirror so arranged as to reflect the images of
those objects on to the mirrors in the tubes, where they can be observed from the
eye-piece. An extended locality may be reflected in perspective on a mirror of small
size and by said mirror reflected onto the mirrors in the tubes, thus rendering it
practicable to inspect localities not immediately within range of the end piece.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim, is:
1. The main tube provided with branch tubes and a series of reflectors, one of the
latter being provided for each of said branch tubes and adapted to be arranged at
equal angles with the axial lines of the tubes; substantially as set forth.

page_text: 2. The main tube having a telescope at one end and the reflector or reflectors and
branch at the other; substantially as and for the purposes set forth.
3. The main tube having the eye-piece, the reflector or reflectors and the end piece,
the whole arranged and operating substantially as set forth.
Dated this Third day of October, A.D. One thousand eight hundred and
EDWARD AUGUSTUS TRAPP
Haseltine, Lake & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.