Improvements in Distance Measuring Instruments or Apparatus.
Year: 1892

page_text: Date of Application, 2nd Aug.. 1892
Complete Specification Left, 26th Apr., 1893-Accepted, 29th July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Distance Measuring Instruments or Apparatus.
A communication by AUGUST UNGERER, Junr., of Munich, in the Kingdom of
Bavaria, Bath Proprietor.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6 Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn in the
County of Middlesex Civil Engineer, do hereby declare the nature of this inven-
tion to be as follows:-
This distance measurer depends on the mathematical rule that in a triangle the
sum of the three angles equal to 180 degrees, and that a triangle may be
determined by means of one side and its adjacent angles.
The instrument consists of a tube of suitable length in which a mirror capable of
revolving on a vertical axis and parallel to the plane, is arranged in such a way
that it may be moved in either direction several degrees out of its normal position
by means of a small arm actuated by a micrometer screw and a spring bearing
thereon.
The normal position is that in which the mirror stands at an angle of 45 degrees
to the axis of the tube, or the line of sight, which is settled when the instrument is
made or adjusted.
The mirror is perforated at an angle of 45 degrees, that is, in the normal position
parallel to the line of sight, or is not coated at the point in question, so that, in
combination with a spy hole made in the centre of the end of the case, a diopter
sight is formed through which the limit may be viewed. The tube is provided with
an aperture at the side of the tube, close to the end provided with the mirror,
which may be closed when the instrument is not in use by means of a sliding cover
or other suitable device.
The manipulation of the instrument, when in use, is as follows:-
Two observers are necessary for determining a distance, each of whom employs
an instrument of the kind herein before described. The two observers take up such
a position, as regards the direction of the limit, that the instruments are arranged
symmetrically to each other, and their mirrors are opened towards each other.
The two instruments or their stands are then connected by a measuring chain or
the like, or placed on inserted bases (the two bases, however, standing in simple
arithmetical proportion to the angle plan of the instrument) so that thus the
distance apart of the two distance tubes is known.
Both observers sight the limit through the central holes above mentioned. Each
of them, however, sees simultaneously the objects which are situated respectively
to the right or left of them through the side opening in the tube, which is capable
of being closed by the sliding cover.
It is then the duty of each observer, on the simultaneous sighting of the limit, to
look for the picture of a small rod or chain which is suspended from an extension
of the mirror axis of the instrument, used by his colleague, by slightly turning the
tube on its axis, and moving the mirror by means of the micrometer screw, and theu
to cover it with the centre hole of his own mirror or with the imagined line of
sight of the limit.
When this has been done by both observers practically simultaneously, which
may be indicated by the persons measuring calling out to one another, the reading
off on the scale of the micrometer screw of each instrument is performed.
There is applied a suitable scale of whole numbers, and a scale of hundredths is

page_text: provided on the rim of the head of the screw, so that, when the screw has been
adjusted, the reading may be taken accurately.
After calling out the results of both observations, the simple addition or sub-
traction of the + or - readings takes place, which result according to the direction
of rotation of the micrometer screw, and which are easily ascertained by the different
colouring of the markings.
This sum or difference gives directly the small opposite angle of the triangle.
The distance numbers corresponding to the possible angles are engraved on the
tube in an easily legible manner.
A free
The operation may be performed either free handed or with small rests.
handed measuring is when the observers simply connect their instruments by means
of a measure (measuring chain), which may be made of wire, cord or any suitable
material, representing the desired length of base.
When small rests are used, the tubes rest in suitable tube holders which are
provided with ball joints, and are fastened on small stands, which are then
connected by the measuring line, which is preferably wound and unwound on
a reel.
The measuring with rests will be seen to be far more exact and speedy than the
free hand method.
The arithmetical calculations may be limited to such an extent that the length
of the mirror arm and the screw are so calculated that one revolution of the
micrometer screw equals one degree of the division scale, and, further, 17.455 metres
(or a part or multiple thereof) may be taken as a suitable basis on account of the
proportions of this length (measurement) to the opposite angle.
The centre of the mirror hole may be fixed by means of a vertical thread, and
each of the distance tubes for obtaining more exact measurements or greater
distances may be connected to a hair cross telescope parallel to or in a line with it.
Dated this 30th day of July 1892.
WM. P. THOMPSON & CO.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Distance Measuring Instruments or Apparatus.
A communication by AUGUST UNGERER, Junr., of Munich, in the Kingdom of
Bavaria, Bath Proprietor.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn, in the County
of Middlesex, Civil Engineer, 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:-
This distance measurer depends on the mathematical rule that in a triangle the
sum of the three angles is equal to 180 degrees, and that a triangle may be
determined by means of one side and its adjacent angles.
Referring to the accompanying drawing-
Figure 1 shows a symmetrical plan of two observers taking a measurement;
Figure 2 shows a horizontal section of the instrument;
Figure 3, a cross section, and
Figure 4 a plan of the same.
The instrument consists of a tube a of suitable length in which a mirror c capable
of revolving on a vertical axis b is arranged in such a way that it may be moved in
either direction several degrees out of its normal position by means of a small
arm d actuated by a micrometer screw e and a spring bearing thereon f.
The normal position is that in which the mirror stands at an angle of 45 degrees

page_text: to the axis of the tube, or the line of sight, which is settled when the instrument is
made or adjusted.
The mirror is perforated in the centre at g at an angle of 45 degrees, that is, in
the normal position parallel to the line of sight, or is not coated at the point in
question, so that, in combination with a sight hole i made in the centre of the end h
of the case, a diopter sight is formed through which the object may be sighted.
The tube a is provided with an aperture at the side of the tube, close to the end
provided with the mirror, which may be closed when the instrument is not in use by
means of a sliding cover or other suitable device l.
The manipulation of the instrument, when in use, is as follows-
Two observers are necessary for determining a distance, each of whom employs
an instrument of the kind herein before described. The two observers take up such
a position, as regards the direction of the limit, that the instruments are arranged
symmetrically to each other, and at angles equally inclined to the base, and their
mirrors are opened towards each other (see Figure 1). The two instruments or
their stands hereinafter described are then connected by a measuring chain or the
like, so that thus the distance apart of the two distance tubes known.
Both observers sight the limit through the central holes ig above mentioned.
Each of them, however, sees simultaneously in the mirror the objects which are
situated respectively to the right or left of them through the side opening & in the
tube, which is capable of being closed by the sliding cover.
It is then the duty of each observer, on the simultaneous sighting of the limit to
look for the picure of a small rod or chain m (Figure 3) which is suspended from an
extension of the mirror axis of the instrument, used by his colleague, by slightly
turning the tube on its axis, and moving the mirror by means of the micrometer
screw e and then to cover it with the centre hole of his own mirror or with the
imagined line of sight of the limit.
When this has been done by both observers practically simultaneously, which
may be indicated by the persons measuring calling out to one another, the reading
off on the scale of the micrometer screw of each instrument is performed.
There is applied a suitable scale of whole numbers at n, and a scale of hundredths
at o is provided on the rim of the head of the screw, so that, when the screw has
been adjusted, the reading may be taken accurately.
-
After calling out the results of both observations, the simple addition or
subtraction of the or readings takes place, which result according to the
direction of rotation of the micrometer screw, and which are casily ascertained by
the different colouring of the markings.
This sum
or difference gives directly the small opposite angle a of the
triangle A. B L, Figure 1.
The distance numbers corresponding to the possible angles are engraved on the
tube, as shown in Figure 4, in an easily legible manner.
The operation may be performed either free handed or with small rests. A free
handed measuring is when the observers simply connect their instruments by means
of a measure (measuring chain), which may be made of wire, cord or any suitable
material, representing the desired length of base.
When small rests are used, the tubes rest in suitable tube holders which are
provided with ball joints, and are fastened on small stands, which are then
connected by the measuring line, which is preferably wound and unwound on a
reel.
The measuring with rests will be seen to be far more exact and speedy than the
free hand method.
In order that the arithmetical calculations may be facilitated the length of the
mirror arm and the screw are so calculated that one revolution of the micrometer
screw equals one degree of the division scale, and, further, 17.455 metres (or a
part or multiple thereof) may be taken as a suitable basis on account of the simple
proportions of this length to the opposite angle.
The centre of the mirror hole may also be fixed more exactly by means of a

page_text: vertical thread, and each of the distance tubes for obtaining more exact measure-
ments or greater distances may be connected to a hair cross telescope parallel to
or in a line with it.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is―
1. A distance measuring instrument or apparatus consisting of two distance
tubes a symmetrically placed at a given distance apart and directed towards the
limit, the tubes containing each a perforated mirror e revoluble on its vertical axis
and adjustable by means of a micrometer screw e and also provided with a chain,
rod, or the like m attached to the extension of the axis of the mirror, reflectable
on the other mirror through openings of the tubes a, for use, in combination
with scales marked on the instruments, substantially as hereinbefore described.
2. The combination of each of the distance tubes a described in Claim 1, with a
hair cross telescope which may be arranged either parallel to, or before or behind
the distance measurer, for the object of enabling the distance measurer to be used
for greater distances.
Dated this 25th day of April 1893
WM. P. THOMPSON & Co.,
Agents for the Applicant.