IMPROVEMENTS IN CLINOMETER' INSTRU- MENTS
Year: 1876

page_text: LETTERS PATENT to Alan Charles Bagot, of Churchdale-Rugeley, in the County
of Stafford, for the Invention of "IMPROVEMENTS IN CLINOMETER' INSTRU-
MENTS"
'
aled the 14th November 1876, and dated the 27th May 1876.
PROVISIONAL SPECIFICATION left by the said Alan Charles Bagot at the
Office of the Commissioners of Patents on the 27th May 1876.
ALAN CHARLES BAGOT, of Churchdale-Rugeley, in the County of Stafford.
PROVEMENTS IN CLINOMETER' INSTRUMENTS."
"IM-
The Invention relates to certain improvements in and additions to that class of
instrument know as the " clinometer" employed by surveyors and others for
taking levels, heights, angles, and depressions.
The present Invention is designed for the purpose of extending the use of the
clinometer by adapting thereto a reversible telescope and a prismatic compass in
such a manner that levels, heights, horizontal angles, or angles of any inclination
or depression can be taken with accuracy and facility, also draining operations.
33
The improvements consist in mounting upon the upper limb of the "clinometer
a telescope which may be fixed or reversible (the latter being preferred), and fixing
in the lower or horizontal limb a prismatic compass provided with a telescopic
sight. The reversible telescope of the upper limb is arranged so as to swivel on
its bearing centre in a plane parallel with the edge of the upper limb, and the
telescopic sight of the prismatic compass will enable objects to be sighted with
accuracy at a great distance, also to read the angle without taking the eye off'
the object.
As an example how the instrument is used when employed for one of its purposes
(viz.), taking the height or summit of any object, it will be necessary to proceed as
follows:- -First determine the length of the base line and level by the spirit level
in the lower horizontal limb of the instrument, the upper limb carrying the
reversible telescope is then raised until the cross wires of the object lens are in a
line between the observer's eye and the top of object, the altitude of which it is
proposed to measure, the angle at which the upper limb then stands at can be
read off on the arc of the instrument; for instance, suppose the angle at which the
upper limb rests be 19° it will be found on referring to a table inscribed upon
the instrument that an angle of 19° corresponds to a rise of one inch in three
inches, if therefore the base line be taken at 300 yards the height of the object
[Price (id.]

page_text: will be 100 yards. The telescope being reversible it can be used in a manner
similar to that previously described for taking depressions. The arc of the
instrument is also provided with a scale which enables the altitude of any object
to be read off as rise in inches per yard.
I would remark in conclusion that the novel combination of a prismatic compass 5
with a
"clinometer" affords great facility for measuring horizontal angles in
connection with the use of the telescope and graduated are of the instruinent. The
telescopic sight of the prismatic compass also enables objects at a distance to be
sighted with minute accuracy.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alan Charles Bagot in the Great Seal Patent Office on the 25th
November 1876.
"IM-
ALAN CHARLES BAGOT, of Churchdale-Rugeley, in the County of Stafford.
PROVEMENTS IN CLINOMETER INSTRUMENTS."
"
The Invention relates to certain improvements in and additions to that class of
instrument known as the "clinometer" employed by surveyors and others for
taking levels, heights, angles, and depressions.
The present Invention is designed for the purpose of extending the use of the
"clinometer" by adapting thereto a reversible telescope and a prismatic compass
in such a manner that levels, heights, horizontal angles, or angles of any inclination
or depression can be taken with accuracy and facility. The improved instrument
is also particularly serviceable when employed in the construction of drains.
"
The improvements consist in mounting upon the upper limb of the "clinometer
a telescope, and in the lower limb a prismatic compass provided with a telescopic
sight. The telescope of the upper limb is constructed by preference so as to swivel
on its bearing centre in a plane parallel with the upper surface of the limb to
which it is secured, and the telescopic sight of the prismatic compass is so arranged
that objects can be sighted with accuracy at a great distance, the angle can also
be read without taking the eye off the object.
In order that the Invention may be well understood and explained in detail, I
have hereunto annexed a Sheet of Drawings made about full size, in which Figure 1.
represents a general view of the "clinometer" when closed, and Figure 2 reprosents
an end view of the same.
In these Figures a is the upper and b is the lower limb of the instrument; to the
upper edge of the limb a is secured a telescope c, which is permanently fixed thereto
and supplied with reversiable lenses, or such telescope may be arranged to swivel
thereupon in a plane parallel with the surface to which it is connected. The
lower limb b is provided with a prismatic compass d and telescopic sight if desired.
As an example how the instrument is used when employed for one of its purposes
(videlicit), taking the height or summit of any object, it will be necessary to proceed
as follows: First deterinine the length of the base line, then level the instrument by
the spirit level placed in the lower horizontal limb b, the upper limb a and telescope c
are then raised until the cross wires of the object lens are in a line between the
observer's eye and the top of object the altitude of which it is proposed to measure,
the angle at which the upper limb then stands is read off on the divided are g of
the instrument; for instance, suppose such angle to be 19° it will be found on
referring to the table inscribed upon the instrument at h that an angle of 1.9°
corresponds to a rise of one inch in three inches, if therefore the base line be taken
at three hundred yards the height of the object will be one hundred yards. The
telescope c when inade reversible can be readily used for taking depressions, or if
fixed interchangeable lenses may be employed as an equivalent. The arc g of the
instrument is also provided with a scale which enables the altitude of any object to
be read off as rise in inches per yard.

page_text: I would remark in conclusion that the novel combination of a prismatic compass
with a clinometer affords great facility for measuring horizontal angles in con-
nection with the use of the telescope and graduated are of the instrument. The
telescope sight of the prismatic compass also enables objects at a distance to be
sighted with minute accuracy.
Therefore what I claim as new and secured by the herein-before in part recited
Letters Patent is, the novel adaptation to clinometer instruments of a telescope and
prismatic compass to be used in the manner and for the purpose as herein-before
substantially described and set forth and illustrated in the Drawings annexed.
In witness whereof, 1, the said Alan Charles Bagot, have hereunto set my
hand and seal, this the 24th day of November, in the year of our Lord One
thousand eight hundred and seventy-six.
ALAN CHARLES BAGOT. (LS.)