AN IMPROVEMENT IN RANGE FINDERS
Year: 1876

page_text: LETTERS PATENT to Augustus Syré, of Vienna, in, the Empire of Austria,
Merchant, for the Invention of "AN IMPROVEMENT IN RANGE FINDERS."
PROVISIONAL SPECIFICATION left by the said Augustus Syré at the Office
of the Commissioners of Patents on the 18th November 1876.
AUGUSTUS SYRE, of Vienna, in the Empire of Austria, Merchant.
MENTS IN RANGE FINDERS."
"IMPROVE-
My Invention relates to the construction of an instrument for measuring distances
from a given point without a staff, and which is adapted for military or non-
military operations. This instrument contains the base of the triangle requisite
for ascertaining the distance of a remote and possibly inaccessible object by
measuring one of the angles at the base, the other angle being known.
It consists essentially of two telescopes provided with cross hairs mounted upon
one stand at a given distance apart, and parallel with one other accurately adjusted
at right angles to a line drawn through the centre of the stand, which line forms
the base of the triangle herein-before referred to, the cross hairs being immovable in
the one whilst the vertical cross hair in the other telescope is capable of being
adjusted by means of a micrometer screw, and brought exactly into the line drawn
from the distant object to that end of the base of the triangle opposite to the known
angle herein-before referred to. The value of the angle may then be lead off partly
on a graduated scale indicating the number of entire revolutions, and partly on a
drum on the screw indicating portions of revolutions, and the distance of the object
may then be formed by means of a calculating table provided for the purpose.
In carrying out this Invention the two telescopes are attached to the extremities
of the fixed base in such a manner that the optical axes are almost parallel in space,
and that the relative positions of the lines of vision can be ascertained in the most
simple mauner. The two telescopes are connected by means of two conical tubes,
say, for example, of brass soldered together at their larger ends upon a short internal
tube, whilst the small ends carry the supports of the telescopes.
The telescopes may have a focal distance of, say 1 foot, and magnify objects,
say 20 times; one of the telescopes herein-after termed No. 1 contains two cross
hairs, by means of which the instrument may be directed upon the distant object,

page_text: whilst the other telescope herein-after termed No. 2, provided with a micrometer
screw, serves to measure the angle formed by the said distant object.
In order to obtain the perfect parallelism of the telescopes before each operation
two small collimation telescopes are fixed across the former in the direction of the
axis of the transverse tube serving as a base, the one on the right being provided
with cross hairs in the form of a St. Andrew's Cross, and the one on the left having
a single hair placed vertically. The telescope No. 1 which is on the left hand in
the present example, can be adjusted on a fixed point by looking through the corre-
sponding collimation telescope, and turning an adjusting screw until the vertical hair
before mentioned is brought over the point of intersection of the cross hair in the other
collimation telescope, and consequently the exact parallelism of the telescopes will
be obtained. The perfect correction of the parallelism is effected on the first
examination of the instrument before it is used in the manner herein-after indicated
by means of a screw which enables the vertical hair to be adjusted in the proper
position.
Two grooved rings fixed on the conical tubes enable the double cone tube serving
as a base, and provided with its two telescopes to be supported upon the forked
rests forming part of the support carried on the stand or tripod. The support is
composed of two arms or bearers of a T shape in cross section, at the end of which
are provided the forked rests for the reception of the rings of the double tube. The
support is screwed to a conical axis which works in a socket or bearing formed in a
circular plate or disc secured on the head of the tripod or stand. The support is
secured to the plate by means of a collar which is caused to grip the latter tightly
by means of a screw.
A steel head is provided at the end of an arm formed on the collar and moves in
an angular opening formed in a projection under the support, and is pressed forcibly
against an adjusting screw provided at one side of the said opening by the action
of a spring fitted at the other side enclosed in a case.
By turning the screw the upper part of the instrument may be adjusted with
precision in a horizontal plane upon the vertical axis. The circular plate or disc
before mentioned is securely attached to the head of the tripod or stand by means
of bolts provided at one end with nuts, and at the other end with two lateral
projections which are passed through elongated holes in the plate and head of the
stand, and then being turned partly round are caused to bind the parts firmly
together by turning the nuts. The legs of the tripod or stand are held in position
when in use by jointed arms on the head of the stand provided with tightening
screws which are caused to grip the legs of the stand firmly. The telescope No. 2
is provided with a vertical and movable hair; the motion of the hair is calculated
by means of the micrometer screw, the complete revolutions of which are recorded
on a scale visible in the optical field of the telescope; the 10ths and 100ths are
indicated on a graduated drum which may be marked with 100 divisions in such a
manner that the 1000ths may be calculated upon it when great distances are
concerned.
The operation of measuring distances is carried out in the following manner :-
The stand or tripod having been erected the support on the conical axis is placed on
the circular plate on the head of the stand, and the screws for connecting the plate
to the head of the stand are placed in position turned 3/4 round and screwed homo.
This having been effected the double table provided with its two telescopes is then
placed in position on the two grooved rings. After carefully adjusting the apparatus
a small amount of play is allowed to the screw of the collar, and by a circular
motion of the entire instrument around the vertical axis, and the upper part upon
the horizontal axis formed by the grooved rings, the axis of the left telescope, No. 1,
is brought approximately in line with the object, the distance of which from the
instrument it is desired to ascertain. This having been effected the last-mentioned
screw is tightened, and applying the eye to the eye piece of the collimation
telescopes the adjusting screw turned until the vertical hair of this tube coincides
exactly with the point of intersection of the cross hairs in the collimation telescope

page_text: corresponding to No. 2. The telescope No. 2 is then set with its vertical hair
exactly upon the distant object by means of the adjusting screw, and then looking
through the telescope No. 2 the cross hair in the same is to be brought as exactly
as possible over the object by turning the micrometer screw. The number of the
complete revolutions may then be read off from the graduated scale which is visible
on the telescope, whilst the fractions may be read off from the drum, the distance
of the object may then be ascertained by means of a table prepared for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Augustus Syré in the Great Seal Patent Office on the 18th May
1877.
AUGUSTUS SYRE, of Vienna, in the Empire of Austria, Merchant.
MENT IN RANGE FINDERS."
"AN IMPROVE-
My said Invention relates to improvements in the construction of range finders
or instruments adapted for military or non-military operations for measuring distances
from a given point without a staff, the instrument containing the base of the triangle
requisite for ascertaining the distance of a remote and possibly innaccessible object
by the measurement of one of the angles at such base, the other angle of which is
known.
My improved apparatus in its general features consists of two telescopes provided
with cross hairs, and mounted parallel the one with the other at a given distance
apart, upon one and the same stand, and capable of being accurately adjusted
in the manner herein-after described at right angles to a line drawn through the
centre of such stand, and which forms the base of the triangle, the cross hairs of
one telescope being immovable, whilst a single cross hair with which the other
telescope is provided is capable of being adjusted by means of a micrometer screw,
and brought exactly into the line drawn from the distant object to the end of the
base of the triangle opposite to that at which the known angle is situate. The
value of the angle may then be read off partly on a graduated scale indicating the
number of entire revolutions, and partly on a drum on the screw indicating fractions
of revolutions, and the distance of the object may then be found by means of a
calculating table provided for the purpose.
And in order that my said Invention may be fully understood, I shall now pro-
ceed more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of my Drawings represents a sectional elevation of the range finder, and
the remaining Figures represent details, and will be herein-after referred to.
F, F¹, are the telescopes which are attached to the extremeties of the frame R, R¹,
the imaginary central line a, a, of which represents the fixed base. This frame is
composed of two conical brass tubes R, R₁, soldered or welded together at their
larger ends upon a short internal tube Q, whilst the small ends carry the supports
L, L', of the telescopes, as shewn clearly in Figure 1 and in the details of the con-
nections, Figures 2 and 3.
pro-
The telescopes may have a focal distance of, say 1 foot, and magnify objects, say
twenty times; the telescope F contains two cross hairs by means of which the
instrument may be directed upon the distant object, whilst the telescope F¹,
vided with a micrometer screw m, serves to complete the triangle, the other two
sides of which are formed respectively_by_an_imaginary axial line passing through
the centre of the telescope F and by the base a, a.
In order to obtain the perfect parallelism of the telescopes F, F¹, before each
operation, two small collimation telescopes V, V₁, are fixed across the former in the
direction of the axis a, a, of the transverse tube serving as a base one, viz, that V¹

page_text: on the right for example being provided with cross hairs in the form of a St.
Andrew's Cross, and the other on the left V having a single hair placed vertically.
The telescope F can be adjusted on the fixed point b, see Figure 1 and the detail
Figure 1, the turning the screw a¹, a¹, Figure 1, and Figure 1b, whilst looking
through the collimation telescope V until the vertical hair of the latter is brought
over the point of intersection of the cross hairs in the collimation telescope V¹ and
consequently the exact parallelism of the telescopes will be obtained. The perfect
correction of the parallelism is effected on the first examination of the instrument
before it is used by means of a screw c which enables the vertical hair with which
the telescope F is provided to be adjusted in the proper position.
On the tubes R, R¹, respectively are secured two grooved rings M, M³, which are
carried upon forked rest U, U₁, forming part of the support attached to the stand
or tripod e, e¹, on which the instrument is mounted. The support is composed of
two arms or bearers B, B¹, of a T shape in cross section, shewn in Figure 1 and in
dotted lines in the detail transverse section, Figure 4, at the ends of which are
provided forked rests U, U¹, before mentioned for the reception of the rings M, M³,
of the double tube R, R¹. This support is attached by screws s or otherwise to a
conical axis A which works in a socket or bearing formed in a circular plate or
disc T secured on the head e¹ of the tripod or stand e, c¹.
The support is secured to the plate T by means of a collar D, shewn in Figure 1,
and in the detail plan, Figure 5, which is caused to grip the plate tightly by means
of a screw P.
At the extremity of an arm D' formed on the collar D there is provided a steel head
Z which moves in an angular opening Z' formed in the lower part of the support U
(see Figure 4) and is pressed forcibly against an adjusting screw E provided at one
side of the said opening by the action of a spring E¹ fitted at the other side and
enclosed in a case G.
By turning the screw E the upper part of the instrument may be adjusted with
precision in a horizontal plane upon the vertical axis A so as to bring the telescope F
in a line with the object. The plate or disc T is securely attached to the head e¹
of the tripod or stand e, e¹, in the manner shewn clearly in Figure 1, and in the
details, Figures 6, 7, and 8, by means of bolts & provided at one end with nuts a¹
and at the other end with two lateral projections d² which are passed through
elongated holes d³ in the plate T and holes in the head e¹ of the stand, and then
being turned partly round are caused to bind the parts firmly together by the act
of turning the nuts d'. The legs of the tripod or stand are held in position when
in use by jointed arms fon the head e' of the stand provided with tightening screws g
which are caused to grip the legs e of the stand firmly. The telescope F on the
right hand is provided with a moveable vertical hair, the motion of such hair being
calculated by means of the micrometer screw mh the complete revolutions of which
are recorded on a scale visible in the optical field of the telescope, the tenths and
one hundreths being indicated on the graduated drum t which is marked with
one hundred divisions in such a manner that the one thousandth may be calculated
upon it when great distances are to be measured.
The operation of measuring distances is carried out in the following manner :-
The stand or tripod is taken out of its case, set up, and put together with all its
parts, the support B on the conical axis A is placed on the circular plate T on the
head e¹ of the stand, and the screws d for connecting the said plate to such head are
placed in position turned 3/4 round and screwed home. This having been effected
the double tube R, R³, provided with its two telescopes F, F¹, is then placed in
position on the two grooved rings M, M. After carefully adjusting the apparatus
a small amount of play is allowed to the screw P of the collar D, and by a circular
motion of the entire instrument around the vertical axis A. and the upper part upon
the horizontal axis formed by the grooved rings M, M', the axis of the left telescope F
is brought approximately in line with the object the distance of which from the
instrument it is desired to ascertain. This having been effected the screw P is
tightened, and applying the eye to the eye-piece of the collimation telescopes the

page_text: adjusting screw a¹ is turned until the vertical hair of the collimation telescope V
coincides exactly with the point of intersection of the cross hairs in the collimation
telescope V. The telescope F on the left hand is then set with its vertical hair
exactly upon the distant object by moving the instrument bodily on its pivot A by
the act of turning the adjusting screw E, Figure 4, and then looking through the
telescope F¹ on the right hand, the cross hair in the same is to be brought as exactly
as possible over the object, by turning the micrometer screw m the number of the
complete revoltions may then be read off from the graduated scale which is visible
in the telescope whilst the fractions may be read off from the drum, the distance of
the object being thence ascertained by means of a table prepared for the purpose
and corresponding to the indications on the scale and drum t¹.
These operations will be clearly understood by reference to Figure 9, which is a
diagram illustrating the principles on which the distance of a remote object is ascer-
tained by means of the range finder herein-before described. In this Figure letter N
represent a remote object the distance of which it is desired to ascertain; o the centre
of the telescope F, and O the centre of the telescope F¹; join these points and form
the triangle o, N, O, then the length of the base o, O, being known as well as the
angle N, o, O, which is a right angle, the opposite angle at the base o, O, N, is
measured by turning the micrometer screw m as herein-before described until the
hair in the telescope F¹ is brought over the remote object N, then the requisite con-
ditions for calculating the length of the two sides o, N, and O, N, will be fulfilled,
and the desired measurement may be readily obtained from the table calculated for
the purpose by reading off the number of revolutions and fractions of revolutions
described by the screw m as indicated by the scale in the telescope and on the drum t
as herein-before.described.
Having now described and particularly ascertained the nature of my said Invention,
and the manner in which the same is or may be used or carried into effect, I would
observe in conclusion, that what I consider to be novel and original, and therefore
claim as the Invention secured to me by the herein-before in part recited Letters
Patent is,--
First. Effecting the measurement of the angle necessary for determining the
distance by means of a micrometer, screw acting upon an adjustable cross hair of one
of the telescopes, substantially as herein-before described.
Second. Effecting the parallel adjustment of the two sighting telescopes by means
of collimation telescopes connected to such sighting telescopes, substantially as herein-
before described.
In witness whereof, I, the said Augustus Syré, have to this my Specification
set my hand and seal, this Sixteenth day of May, One thousand eight