Improvements in and relating to Apparatus for use in Surveying Land.
Year: 1891

page_text: Date of Application, 19th June, 1891
Complete Specification Left, 18th Mar., 1892-Accepted, 19th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in and relating to Apparatus for use in Surveying
Land.
I, JEAN DANIEL FRANCOIS SCHRADER, of 95, Boulevard Beaumarchais,
Paris, in the Republic of France, do hereby declare the nature of this invention
to be as follows:-
My invention relates to apparatus for use in surveying land.
The improved apparatus constructed according to this invention is designed for
automatically indicating the elements or results of a topographic survey in order to
substitute a direct survey for the reading of angles and calculations which have
heretofore been used for obtaining this survey.
For fulfilling this object the apparatus must transform each sighting directed by
the operator towards any point into a line which enables the three co-ordinates of
this point to be determined and to be placed directly upon the map.
Two cases may occur; either from the extremities of a line of known length
taken as a basis, a point or a series of points are sighted; or from a point or a
series of points an object of known dimensions, used in place of a staff is sighted.
In the former case the instrument gives elements in the form of a graphic line
enabling direct construction therefrom, and in the second case it traces the survey
directly.
My apparatus comprises a telescope forming one of the sides of an articulated
parallelogram, the two sides of which are held vertical, whilst the lower fourth side
parallel with the axis of the telescope receives in a longitudinal slot a rule carrying
a guide the object of which is hereinafter set forth.
It
The telescope is movable in a vertical plane, turning upon a horizontal axis.
has also a horizontal movement upon the vertical axis, so as to be able to take a
sight at any desired angle. To the telescope is connected a vertical sector the
limb of which is graduated and the centre of which coincides with the horizontal
axis. To the vertical sector and consequently to the telescope is attached a horizontal
rule transforming into a rectilineal movement through the agency of the said
rule every vertical displacement of the telescope; the amount of each movement
of the rule being equal to the length of the axis of the toothed sector displaced.
All these parts are supported upon a horizontal plate. A marking pencil or
stylet is fixed at a suitable point of the horizontal rule its point travelling over the
surface of the said plate on which a sheet of paper is placed. This marking pencil
or stylet moves on a radius of the disc situated in the vertical plane passing through
the axis of the telescope. Accordingly the whole azimuthal plane of the telescope
is transformed by an azimuthal movement of the crayon and the, vertical displace-
ment of the telescope will cause a longitudinal movement of the crayon on a radius
situated in the vertical plane coinciding with the axis of the telescope. Each
sighting is therefore transformed by a well determined point and each series of
sightings will be represented by a continuous line. The azimuths and the zenithal
angles of sighted points will therefore be recorded and preserved together with
their measurable relative values.
A second rule or horizontal arm, independent of the first rule as regards its
longitudinal movement but capable of moving parallel with it, may be connected
with the same marking pencil or stylet by tightening or loosening two screws
which are independent of each other and situated one above the first rule and the
other above the second rule or arm.
This arm, instead of being actuated by the telescope is independent of it and
acts on the contrary upon a movable micrometer in the field of the telescope. .

page_text: The transmission of the movement-is effected as follows: With the said arm is
firmly connected a vertical piece forming an upright and along which travels with
as little friction as possible a projection on a rule so that this rule may at the
same time, as it slides vertically along the upright, slide longitudinally in the guide
following the movement of the aforesaid arm.
By this arrangement the lower side of the parallelogram, the vertical upright,
and the horizontal arm represent the three sides of a right-angled triangle
respectively proportional: first, the hypothenuse, to the sighting distance; second,
the vertical upright to the difference of height of the standing point or staff to the
sighted point; third, the horizontal arm, to the horizontal distance separating
the verticals of these two points. This last distance will be automatically inscribed
upon the graphic survey. The difference of level may be read upon a special
tablet connected with the central upright of the apparatus; at the variable apex
of the angle formed by the hypothenuse and the vertical side of the triangle.
One of the projections or checks of. the said upright carrying a lever which is
adapted to oscillate upon a fixed point, receives at one of. its extremities the action
of an agate point moved by the guide above referred to and transmits through the
other extremity its movement to the movable parts of the micrometer.
Vertical movements are imparted to the above-mentioned sector and to the
telescope by a pinion gearing with the frame of the sector or the tangent rule and
moved by a milled wheel.
The longitudinal movements of the second rule or arm are transmitted to the
marking pencil by a pinion gearing with the said rule or arm and actuated through
a milled wheel.
The azimuthal or circular movements are transmitted' to the whole apparatus by
a double lever arranged in such a manner that its two uprights form with the
frame of the instrument a strongly braced figure in. order to prevent' any lateral
flexion.
For movements of very small amplitude this double lever is completely lowered
by causing it to turn upon its pivot. A small wheel.then comes in contact with
the disc and by rotating the milled wheel the rotation of the instrument upon its
axis is caused.
For raising the marking pencil after it has registered the small rod is pressed
down which has the effect of raising the collar mounted upon the radius bar of the
said frame.
A disc may be graduated upon its periphery and provided with a vernier fixed at
the extremity of the frame supporting the horizontal rule, the arm and the marking
pencil or stylet, the latter being surmounted by a rod carrying a small cup con-
taining a weight of suitable variable proportions.
The level, the telescope and its parts may be adjusted by construction or
independently.
A level fixed in the vertical plane of the telescope permits the perfect
horizontality of the system to be established:
In case it should be desired to obtain merely the distance of a sighted base, the
horizontal rule might be dispensed with and also the parts which transmit to it the
movement of the vertical sector. It would then be sufficient to make use of
She remaining parts.
In the opposite case where it is required' to obtain only the sightings taken from
the extremities of a given base towards a common point the parallelogram and the
annexed parts may be dispensed with.
If in an exceptional case it should be desired to obtain merely the simple
projection of an oblique surface upon a plane it would be sufficient to act directly
through the horizontal rule upon the micrometer.
The operation of the apparatus is as follows:
The levelling does not differ from that of the other levelling apparatus.
When the instrument has been levelled two series of operations may have to be
performed according to the manner in which the work is carried out as in the

page_text: first or second of the two cases hereinbefore recited. In both cases we suppose a
surface of paper or-metal previously fixed-upon the disc.
First case from the extremities of a known base, sight and inscribe one or more
points or continuous 'lines.
(1) Raise the marking pencil or stylet.
(2) Put the zero of the sector in contact with the zero of the vernier by means
of one of the said milled wheels.
(3) Lower the marking pencil or stylet and cause the instrument to describe,
through the medium of a lever, a complete revolution. The marking pencil or
stylet then traces a circle which corresponds to the horizontal-plane passing through
the telescope.
(4) Raise the marking pencil or stylet and move the telescope, by a simultaneous
movement of the aforesaid milled wheel and lever to the position in which the
centre of the carriage coincides with the point through which the series of sights
is to be commenced. A vertical movement (from the said milled wheel) gives the
azimuth. A horizontal movement (from the said lever) gives the zenithal height.
These movements are repeated several times if the measurement is required to be
very exact; the result of the above mentioned movements being a small cross the
centre of which indicates the position of the point required.
(5) If it is desired to substitute for the isolated sights a continuous sight, and for
the tracing of the points, that of a line, the eyes of the operator are fixed upon a
black point marked at the centre of the carriage of the telescope, then by a
simultaneous movement of the said lever and milled wheel (unconscious and
instinctive corresponding movement of the hands the black point is followed by
the line or outline produced upon the disc representing the profile of a mountain,
water-course, outline of a village, or track of a way or path or the like).
The corresponding line is inscribed mechanically each point of this line being
measurable as to azimuthal and zenithal height.
(6) Care is taken to mark by the side of the crosses or lines the names which
serve to recognize them again.
When the sighting operation has been finished a plane outline figure is obtained,
reproducing,all the parts of the horizon which are to be determined.
By then
separating the disc from the other parts of the instrument it can be used as a table
for completing the outline between and by joining up the lines of the automatic
tracing. In this manner a measurable outline panorama is completed.
(7) For transcribing on to a map the data furnished by such horizontal outlines
it is sufficient to know the position of the two known standpoints, to direct the two
horizontals of these standpoints by carrying from each of these points towards the
opposite point, the corresponding radius and to proceed, by intersection to obtain
all the other points; and then to continue from place to place for all the successive.
horizontals, always proceeding from the points which are already known.
(8) The distances of the various points being given by their intersections their
differences of level can be deduced from the reading of their zenithal angles by
means of tables generally in use at the present time. The corrections of the
sphericity, of refraction and the like may be likewise read from these tables.
Second case.
From a given sighting point and a levelling staff of known
dimensions to obtain the direct outline of the successive positions of this levelling
staff in the form of a map or plan.
(1) Clamp the marking pencil or stylet upon the horizontal arm whilst disengaging
the same from the horizontal rule.
(2) Move the guide to the proper position, then raise the marking pencil or
stylet.
(3) By the aid of the aforesaid lever cause the telescope to follow the lateral
movement of the levelling staff. At the same time if necessary the said milled
wheel may be followed and actuated in the various changes of its position.
At each station the horizontal arm a standard and the guide through the turning
of the said milled wheel, carry the micrometer to the point where its two lines

page_text: coincide with the two extremities of the levelling staff; and the marking pencil or
stylet being lowered, traces upon the disc the distance between the two points,
reduced to the desired scale.
:
(3) With sufficient practice and upon an open ground the operator can follow the
levelling staff continuously and the separation of the lines of the micrometer
varying in the same degree as the direction in azimuth, the marking pencil or stylet
will trace a continuous line corresponding to the contour of the ground passed over
by the levelling staff.
(4) For measuring zenithal angles four methods may be adopted.
Either the operator, after he has traced the horizontal distance clamps the pencil
again upon the horizontal rule and causes it to trace a small cross similar to those
used in the first case; or taking down the whole of the sights obtained in the first
turn towards the levelling staff he will obtain by a supplementary turn of the
horizon a perigraphic panorama which will enable him to complete the outline
resulting from the sightings of the levelling staff; or if he needs only a limited
nninber of zenithal heights he may be content with reading upon the graduated
scale the vertical angle corresponding to each station of the levelling staff, and with
setting down this angle by the side of the relative position of its station.
In these three cases the zenithal distances are transformed into differences of
level by the aid of a simple reading upon a reducing table.
In the fourth case a tablet firmly fixed in the vertical axis in a vertical plane
parallel with that of the optical axis of the telescope and with that of the horizontal
arm will enable the difference of level to be read off directly by the aid of the
intersection of a wire prolonging the axis of the sight, and another wire prolonging
the vertical arm.
The advantages of my apparatus are complete elimination of calculations
replacing written notes by graphic traces which can always be verified; indefinite
augmentation of the number of elevations; introduction into topography of the
system of continuous sights enabling the precise definition of the lines and surfaces
of the ground to be obtained; diminution of the chance of error by the suppression
of the figures and calculations heretofore necessary; diminution of the chance error
by the rapid repetition of the observations and the compensation resulting therefrom;
remarkable acceleration of the work and the preservation in a graphic form of the
elements of this work enabling it to be at any time taken up again or completed.
Dated this 10th day of June 1801
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Apparatus for use in Surveying
Land.
I, JEAN DANIEL FRANCOIS SCHRADER, of 95, Boulevard Beaumarchais,
Paris, in the Republic of France, 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 use in surveying land.
The improved apparatus constructed according to this invention is designed to
automatically trace or draw the elements or results of a topographic survey in order
to substitute a direct tracing for the reading of angles and calculations which have
heretofore been used for obtaining these tracings or plottings.
For fulfilling this object the apparatus must transform each sighting directed by
the operator towards any point into a line which enables the three co-ordinates of
this point to be determined and to be placed directly upon the map.
In the accompanying drawings I have shown by way of example how
invention may be conveniently and advantageously carried into practice.
my
saið

page_text: Figure 2 is a plan of the same.
Figure 3 is an elevation of the apparatus on the side of the eye piece.
Figure 4 is an elevation of the apparatus taken on the left hand side thereof.
Figure 5 is a sample of automatic plotting or tracing surveyed from any suitable-
base.
Figs. 6 to 10 show details of the apparatus.
My improved apparatus consists of a telescope A connected to a sector S by the-
two vertical rods ab joined at their upper part by the horizontal rod c which is parallel
to the axis of the telescope A. The latter is movable within a vertical plane and
turns about the horizontal axis ; it can likewise move horizontally about the
horizontal axis y, so that by this arrangement sights may be taken in any direction.
The centre of the sector coincides with the axis a and as it follows the movements
of the telescope with the aid of the vertical rods a band of the rod c; this sector
carries a horizontal rule B with it. The sector S may be connected to the rule B-
by any suitable attachment, I use for this purpose three parallel metallic strips or
ribbons arranged longitudinally upon the sector and the upper surface of the rule.
One of these strips the central one is fixed to the rear ends of the sector by the
screws and to the front end of the ruler by a point or nail the other two strips.
are fixed at the opposite ends. The horizontal rule B converts into a rectilinear
motion every vertical movement of the telescope, the extent of each motion of the
rule being equal to the length of the arc along which the sector has been shifted.
To enable slight movements to be made and to prevent the apparatus from being
thrown out of adjustment by operating the same by hand, I provide a thumb nut
or milled head C connected with the sleeve D which surrounds the axis y, upon
which the apparatus can be moved horizontally the said thumb nut carrying a.
pinion d gearing with a toothed sector S¹ formed integrally with the sector S.
A carrier (Figure 6) may be firmly connected with the rule B by a screw f
and consequently follow the displacements of this rule B. The carrier E slides
upon two small fixed rules B B against which it is held by a spring E' arranged
at the lower part of the said carrier. The object of this arrangement is to enable.
the carrier to be connected with the rule B or to be disconnected therefrom and
made independent of the same when desired in the latter case it is sufficient to turn.
the thumb screw and the carrier E may then be displaced along the rule B. A
finger prevents the complete removal of the screw in order to avoid the loss of
the latter. The carrier E supports a vertical sleeve e' provided with a longitudinal
groove which receives the stop e fixed upon the pencil holder e when the latter-
has been introduced into the sleeve el. In the manipulation of the apparatus it is
sometimes useful to raise the pencil in order that it shall not leave any trace upon
the paper.
This operation is rendered easy by the arrangement of levers m
Figure 7 it is sufficient to act with a finger upon the lever m which, turning
downwards raises the connecting rod and consequently the pencil holder e through-
the medium of the stop el. If the pencil is to be lowered it is sufficient to move-
the lever m back to the position shown in Figure 7 the rod r is lowered and
therefore the pencil holder. The length of the crayon should be such that in this
latter position the extremity of the pencil shall be in contact with the sheet of
paper arranged upon the disc.
The motion of the carrier E connecting the pencil or style to the rule, allows.of
a sight being taken at a great height by fixing the pencil close to the centre and at
a low height by moving the said pencil away from the centre.
Every vertical movement of the telescope A will impart to the pencil a
longitudinal motion along a radius situated in the vertical plane in which this.
telescope has been moved.
A second rule F, independent of the first in a longitudinal direction but which
is arranged to move parallel thereto may be connected to the piece E carrying the-
pencil by turning down a small notched hinge y shown in dotted lines in Figure 1.
This hinge is fixed upon the slotted bar G (secured to the rule F) by two small

page_text: screws gg. The rule F is independent of the telescope and merely carries with
it another rule I actuating the movable micrometer of the telescope. Upon the
front part of the ruler F, is secured a rack which is actuated by a pinion operated
by the thumb nut or milled head H. By turning this nut. a lateral motion may be
imparted to the rule.
I
:
Within the slotted bar G is arranged to slide with slight amount of friction, al
projection of the rule I which rule may slide within a grooved guiding bar
connected on the one hand to the sleeve D and on the other to the telescope A
through the rod K. The latter always remains vertical, and its connection with.
the rule is arranged in such a manner that the angle formed by the angle or
inclination of the telescope and this rod may vary, that is to say that the telescope A.
the sleeve D, the guide J and the rod K may form a jointed parallelogram the
sides A and J being parallel to each other as well as the sides A and D whatever
may be the position of the telescope. The rule I which may be slid within the
grooved guide J carries at its front part a metal strip L the thickness of which
increases from the extremity 1 to.the end P. This metallic strip acts when the
rule I is moved to the right hand side upon a small piston m and causes it to bear
upon the lever M fulcrummed at the fixed point n. The other extremity of the
lever M acts upon the movable part of the micrometer which is arranged in the
following manner.
The frame m³ is movable and is capable of being approached to or withdrawn
from the fixed part m', it is evident that when the lever M actuated by the lower
piston m comes against the piston m² operating the movable part m³ the latter will
approach the fixed part m and consequently, the wire o attached to the movable
part.will be moved nearer to the wire o' attached to the fixed part. The several.
parts will thus form a jointed parallelogram whose lower side is fixed, and whose
lateral sides 1 and 2 with the upper side are movable; to permit of this motion,
the movable frame has a certain vertical play as shown in the drawing.
The horizontal arm Q Figures 8 and 9 is provided at its extremity with an
opening 3, one of the sides of which is traversed by a screw 4 whilst in the interior:
of the side 5 is arranged a piston 6 provided with a spring 7. In the interior of:
the opening 3 is arranged a clamping device formed of two parts 8 and 9 which are.
pressed one towards another by a screw 10.
The jaw 8 and 9 is fixed to the plate P, one of the sides of the lever Q serves
as a nut for the screw 4 the extremity of which rests on the fixed jaw 89 it is
evident that on rotating the screw in one or the other direction, the jaw being.
fixed to the plate P, a very slight displacement will be given to the lever Q and
thereby to the apparatus, about a vertical axis which supports it. This is of use
when after sighting a point with the telescope it is desired to look at another very.
close to the same and placed at the same level as the first point.
It will be seen, the jaw being secured to the disc or plate P, that by turning the
screw 4 in one direction or in the other, I may give to the lever Q a slight
displacement relatively to the jaw and consequently to the disc or plate P. The
lever Qbeing firmly connected with the whole apparatus the displacements given to:
it by the screw 4 will be communicated to the whole apparatus.
Before particularly describing the mode of operation of the apparatus I will.
proceed to indicate as a résumé of the above description the movements and gearing
of the various component parts of the apparatus.
1. A rotary motion can be imparted by hand to the apparatus upon the axis y
mounted upon the plate P. In this motion should the pencil be lowered, the latter
will describe a circle the centre of which is the point where the axis y meets the
plate.
1
2. By actuating the thumb nut C the sector S is moved by means of the toothed.
sector in this motion the telescope is shifted in a vertical plane, the rule B is
moved on a radius of the plate P and the guide which follows the motion of the
telescope remains constantly parallel to the latter and compels the rule I held
by one of its extremities in the slotted bar G to move slightly relatively to the

page_text: latter and hence to act with the aid of the small piston mand of the lever M upon
the movable part of the micrometer of the telescope..
3. By turning the thumb nut H, the rule F which carries with it the rule I by
means of the slotted bar G, is set in motion and the rule I acts as before through
the strip L of varying thickness through the piston m and the lever M upon. the
movable part of the micrometer..
The apparatus is provided moreover with a spirit: level T for the purpose of
ensuring the exact horizontal position of the whole arrangement:
Having thus described the various parts of my apparatus as well as the
movements which it can accomplish, I will now indicate the means for auto-
matically plotting or tracing with this apparatus the different. parts of a
topographical survey.
1st case. To sight and trace one or more points or continuous lines (Figure 5)
from the extremities of a known base.
1. The rules F and B should be rendered independent of each other by raising
the notched plate y as shown in Figure 1.
2. By means of the thumb nut. C bring the zero point of the sector to coincide
with the zero point of the vernier U.
3. Lower the pencil and impart a complete. revolution to the apparatus by
means of the lever Q.
The pencil describes a circle which corresponds to the horizontal plane passing
through the telescope.
4. When by the displacement of the lever Q and knob C the centre of the field
has been made to coincide with the point from which it is desired to commence the
series of sightings, I effect the focussing by the aid of the knob 12 placed upon
the telescope which acts as in optical apparatus generally.
5. Lower the pencil again by the aid of the lever m¹ after which a vertical
oscillation effected by the nut C will give the azimuth an horizontal oscillation by
means of the lever Q will give the zenith. These oscillations must be repeated
several times whenever great accuracy is required.
Result. A small cross the centre of which indicates the position of the point.
If instead of isolated sights, a continuous sight is required, that is to say if the
tracing of a line is required to be substituted for that of points attention must be
fixed upon a black speck marked in the centre of the field of the telescope then by
a simultaneous motion of the lever Q and of the nut C (which motion is unconscious
and instinctive the black speck is made to follow the line or outline which it is
desired to plot on the paper. In this motion of the telescope the pencil draws
a line.
When the sight taking is completed, a plane perigraphic figure is obtained and
reproduces all the parts in the survey which it has been thought proper to fix. By
then separating the disc or plate from the other parts of the instrument I may use
the same as a small board for completing the tracing by indicating by free-hand
the secondary points which the operator has not thought fit to take through the
telescope. That is to say after having obtained a circle of sightings, I complete
the free-hand drawing by placing the secondary details in the middle of the net of
big lines and by giving to the summits designated by crosses their characteristic
profile. I may also finish the drawing free-hand with a crayon of different colour
so as not to attribute later on to the lines traced free-hand the degree of certitude
which is applicable only to the automatic lines. This being done, the operator
proceeds with the apparatus to the other extremity of the known line taken as a
base of operations. The same sighting is effected there as at the first post.
To convert now into a map plan or chart the results given by the sights taken on
the ground, the two tracings or plottings as shown in Figure 5 are put on paper.
The two horizons are set and the work is carried out by means of intersections.
Thus the point 6 which is the extremity of a lake is obtained on the map by the
intersection of the radii drawn from the points O₁ O, leading to the point in each
tracing.

page_text: 2nd case. From one point, sight a moving object of known dimensions and obtain
the direct tracing of the successive positions of this object in the shape of a map,
-chart or plan.
1. Connect the pencil to the rule F.
2. With the nut H. and lever Q shift the instrument so that-a. The lateral
movement of the object observed may be followed in the telescope by the
aid of the lever Q. . The staff or object observed is carried by a man who moves
upon the profile which is to be traced upon the drawing, the operator acts upon
the parts of the apparatus so that the length of the object shall always be exactly
comprised between the two wires.
The rod or object observed is carried by a man who moves on the outline which
is to be traced on the drawing; the operator actuates the drawing apparatus so
that the length of the object may be always contained between the two wires to
follow the object, the operator will be obliged to displace the telescope and con-
sequently the pencil will mark a line corresponding such displacement.
For measuring zenithal angles or rather for determining the height of sighted
points, during an operation, that is to say, the height of every point over which the
man carrying the staff has passed, it suffices to read these heights on a graduated
-scale inscribed on the mounting G.
The rule I being always parallel to the telescope, it will only. be necessary to
see at what height the point of articulation i is found on the scale in order to
determine the zenithal height of the sighted point.
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. In the improved apparatus designed to produce the automatic and direct
tracing of the ground the arrangement of the pencil or style reproducing on the
paper by the aid of a teothed sector and of a rack all the movements of the
apparatus.
2. In the improved apparatus as above set forth the combination of the movable
telescope, of a toothed sector and of a horizontal rule designed to convert the
vertical movements of the telescope into horizontal motions.
3. In the improved apparatus as above set forth the combination of the telescope
and of a movable rule sliding within a guide parallel to the telescope, the said guide
having for its object to act by the aid of a metal strip upon the movable part of
the micrometer of the telescope.
4. In the improved apparatus above described the mechanical means for allowing
of the pencil or style being connected to or disconnected from one of the two
horizontally moving rules.
5. The combination of the apparatus above described with a lever allowing of
the said apparatus being turned upon a vertical axis fixed in the centre of the plate
upon which the pencil marks are made.
Dated this 18th day of March 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.