An Improved Levelling and Plumbing, also Angle and Gradient Measuring, Instrument for Surveying and other Purposes.
Year: 1892

page_text: Date of Application, 29th Aug., 1892-Accepted. 31st Dec., 1892
COMPLETE SPECIFICATION.
An Improved Levelling and Plumbing, also Angle and Gradient
Measuring, Instrument for Surveying and other Purposes.
I JAMES WILLIAM SHEPARD of 2 Colonnade, Cheltenham, in the County of
Gloucestershire, Gentleman 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 improvements in instruments for use in levelling, and for
taking determining and measuring angles, perpendiculars, distances and gradients,
and for all similar purposes.
The main object of my said invention is to provide a simple instrument for the
aforesaid purposes.
In the accompanying drawing
Fig. 1, is a side elevation of the said instrument in position, adapted for taking,
determining, and measuring horizontal angles.
Fig. 2, a plan on top of Fig. 1, but representing the instrument on its edge in
position adapted for levelling, and taking, determining, and measuring vertical
angles and gradients.
Fig. 3, a sectional plan taken on line a, a.
Fig. 4, a vertical section taken on line b, b.
Figs. 5, and 6, an elevation and plan respectively, of a device hereinafter
described.
Referring to Figs. 1, 2, 3, and 4,-c, is a dished plate made of suitable metal
with an annular recess c¹ formed in the face d, into which I fit a dial plate e, the
outer circumference of which, to the extent of three fourths of same, is divided and
marked into a scale of degrees, and upon the remaining fourth a gradient scale i, is
marked, the divisions being suitably figured.
Upon the face d, of the plate c, I engrave or mark pointers f, by means of
which the various angles and gradients can be read off the scales, according to the
position of the dial plate in relation to the said pointers.
In or upon the dial plate e, I fit a spirit tube h, and the dial plate is arranged to
pivot on the pin g'. The dished plate c, I fit into a straight edge, or stock G, or
any similar suitable receptacle, securing the former in the latter by means of the
threaded ring j, and for the purpose of preventing the dished plate c, turning in
the stock, I provide and fix in the latter pins k, which fit into holes provided in
the plate c, and when the ring j, is screwed up tightly the dished plate c is firmly
secured in the stock G.
I further provide a metal strip or 'straight edge D, of any convenient length and
adjust and clamp same upon the dial e, of the instrument, when desired, for the
purposes hereinafter fully described.
The adjustment is effected as follows:-Two or more holes n, n, are formed in
the strip D, and a semi-circular slot or slots n', n',-corresponding in size to half the
diameter of the pin y,-in one edge of the strip; studs or pins n², n² are provided
on the face of the dial e, and to clamp the strip D, upon the dial e, it is only
necessary to pass the strip over the pins n' and tighten up the nut m, upon the
strip; the nut may only be tightened up sufficiently to steady the strip, on the face..
of the dial e, or upon screwing the said nut down sufficiently the effect will be to
prevent any rotary movement of the dial e, which may be fixed in any desired
position relative to the pointers f, it is obvious that the manipulation of the nut m,
will have the same effect-viz., to fix or steady the dial plate-should the strip D,
not be in place upon the dial, and also, that the instrument can be used either
with, or without the strip D, as may be desired. D', D2, are sights or eyepieces.

page_text: shewn apart in end elevation adjacent to the ends of the strip D, (see Fig. 1.) and
also in position in other views upon the strip, on which they may be mounted at
will and used for the purpose of sighting distant objects or points.
I have shewn at Fig. 1, the instrument on its side, in a horizontal, level position
convenient for taking, determining and measuring horizontal angles, by rotating
the dial, the stock G being first suitably fixed in position; and at Fig. 2, I have
shewn the instrument in a vertical position ready for taking, determining, and
measuring vertical angles, and for levelling purposes, and for taking determining
and measuring gradients.
An important feature of my said invention is the graduated gradient scale i, upon
the dial plate, by means of which gradients are taken, determined, and measured,
in the following manner :-For short gradients remove the strip D, and eye-
pieces D1, D2, then apply the instrument to the gradient and loosen the nut.m, and
rotate the dial plate until the spirit tube indicates dead level, the gradient can then
be read off, the scale i by means of the pointer opposite same, and by dividing the
number of the gradient scale, say 60, by the gradient registered, the proportion is
found, thus supposing the gradient registered on a scale of 60, is 15, then 60,-
divided by 15, equals 4, the answer therefore being one in four, that is, the
gradient is one in four, this example fully illustrates one method of using the
gradient scale.
In passing I note that the gradient scale I prefer to use upon a small dial is that
of one in sixty, but it is obvious that it (the scale) may be other than this if desired
for larger dials.
Short angles of elevation, and depression, may be determined in the following
manner Remove the strip D, and eyepieces D1, D2, and apply the instrument to
the angle, and loosen the nut m, and rotate the dial plate until the spirit tube in
same indicates dead level, the angle, by means of one of the pointers, can then
be'read off upon the scale of degrees marked upon the circumference of the dial
plate e.
In sighting distant accessible, or inaccessible objects, or points, for the purpose
of measuring distances, or taking angles of elevation or depression, or gradients,
or for extended levelling, the strip D, and eyepieces D', D2, will be clamped on the
dial plate and tlie instrument operated in the following manner. Fix the instru-
ment so that the spirit tube indicates dead level (as shewn at Fig. 2,) then loosen
the nut m, to allow the dial plate with the strip D, to rotate somewhat stiffly and
sight through the eye pieces D1, D2, the angle, or gradient,-by means of one of
the pointers can then be read off' upon the scale of degrees, or gradient scale,
marked upon the circumference of the dial plate. Levels will be obtained in
similar manner.
Distances and heights of accessible and inaccessible objects may by the aid of a
base line be ascertained and calculated from the data obtained by means of my
improved instrument manipulated in manner above described, or similar thereto,
the results being obtained by applying to the data the ordinary well known
geometrical and arithmetrical rules used in such calculations.
When using my instrument I can provide for fixing same in a desired position
by any means suitable for the purpose, for instance, I may arrange for a screw
threaded hole to be formed at the back of the plate c; and to fix the instrument
upon say, a table, stand, or tripod ; a thumb screw, or screw bolt will be passed
through the latter, and screwed into the threaded hole 1, and upon tightening up
the screw it will fix the instrument to the table, or its equivalent, in the desired
position.
:
I may sometimes provide vernier scales upon the face d, of the plate c, to enable
the operator to read off from the dial e, fractional parts of a degree.
When using the instrument in say a narrow trench or elsewhere, where it would
be inconvenient, if not impossible, to see the spirit tube h, the device F, containing
a spirit tube h¹ (see Figs.. 5, and 6,) may be temporarily mounted upon, and
attached to, the dial plate e, in manner as shewn in dotted lines at Fig. 2; so that

page_text: the spirit tube fitted in the dial plate, and in the device F, will indicate the same,
and thus the instrument can be set and worked by the spirit tube contained in the
device F.
This combination of parts constitutes the complete instrument as invented by
me, and the same can be used as a theodolite, clinometer, spirit level, and plumb
rule; and for plotting land, setting out buildings, taking, determining, and measuring
gradients, heights, distances, and angles, and for all similar purposes, the dial e, and
other parts described being manipulated in manner-or similar thereto-as herein-
before described.
My improved instruments are more particularly adapted for use, where, and
when more expensive surveying instruments-such as a theodolite-are not
available, or could not be conveniently used, and for use in areas or spaces within
the natural sight.
It is obvious I can somewhat modify the construction and arrangement of my
instrument without departing from the distinctive character of my invention, but
I attach special importance to the provision of the graduated gradient scale
available and for the purpose specified.
upon the dial
e,
as,
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 :-
1st. The improved instrument consisting of the parts, constructed and arranged
substantially as herein before described.
2nd. The improved instrument adapted for simultaneously taking, determining,
and measuring angles (in degrees and fractional parts of same) and gradients,
substantially as herein before described.
3rd. The strip D, and eyepieces D1, D2, adapted to serve in combination with
the dial e, and other parts of my instrument, substantially as described for the
purposes specified.
4th. The hereinbefore described device F, adapted to serve with the instrument
as and for the purposes specified.
5th. The provision of a gradient scale i, provided upon the dial e, adapted to
serve with the other parts of my instrument as and for the purpose specified.
Dated this 12th day of August 1892.
HERBERT P. BLAKE, M.I.N.A.,
70, High Street, Southampton, Agent for the Applicant.