AN IMPROVED COMBINED CLINOMETER AND PRISMATIC COMPASS
Year: 1884

page_text: I WILLIAM GREEN of 5 Mount Pleasant Clerkenwell, Optician, do hereby
declare the nature of my Invention for "AN IMPROVED COMBINED CLINOMETER
AND PRISMATIC COMPASS," to be as follows:-
This Invention has for its object an improved instrument consisting of a
prismatic compass combined with a clinometer."
In my improved combined instruments, the compass card and the clinometer
card appear upon opposite faces of the instrument. The prism, by the aid of
which the angles are read, is mounted upon a block, which is pivotted to the frame
in such a manner that it may be turned round so as to carry the prism from one
face of the instrument to the other. A catch is provided to retain the block in
either position. Thus the same prism is employed for reading the angles whether
on the compass card or the card of the clinometer.
The frame carrying the sight wire is so jointed to the main frame as to admit of
its being turned through an angle of 270 degrees, it may thus either be laid down
flat and parallel to the card when out of use or it may be erected for use with the
compass card or again it may be reversed for use with the clinometer.
A friction brake is provided to check the vibrations of the compass card. To
raise the compass card off its pivot when not in use, a lever is provided it has two
arms nearly but not quite at a right angle. The longer arm is perforated at its
end and the pivot passes freely through it, and this end of the lever lies beneath
the compass card.
The other or shorter arm of the lever has a pin fixed upon it which projects
through a hole in the case of the instrument and receives a small nut having a
milled edge adapting it to be turned by the fingers. Sometimes a sliding
arrangement is used to raise the lever instead of the milled head."
When the nut is screwed up tightly, in consequence of the form of the lever its
longer end is raised towards the point of the pivot, and it then lifts the card off
the pivot, but when the nut is loosened then the lever by its own weight drops to
the lower end of the pivot clear of the compass card.
Thus as has been explained in my combined instrument, the clinometer and the
compass card are observed upon opposite faces of the instrument, whereas in all
combined instruments of the sort heretofore in use, the compass and the clinometer
have been observed on the same face of the instrument.

page_text: In some cases the clinometer card has been enclosed in a separate box, which
when required for use has to be placed over the box of the compass card, an
arrangement which has this disadvantage amongst others, that the instrument is in
two parts which have to be detached for use, and the moveable part is liable then
to be lost or to receive injury.
In other cases the clinometer card has been mounted above the compass card on
the same face of the instrument, and has an opening in it through which the
compass card can be observed.
This arrangement has the disadvantage that time is unavoidably lost in securing
the clinometer card before the compass can be used. The latter card also is
necessarily deep down in its box, which in some cases renders it difficult for
sufficient light to reach the card to admit of its being easily read; and further, the
clinometer card and the compass card being on different levels an adjustment of
the distance of the observing prism is necessary when passing from observations
with one card to that with the other.
Deted this Oth day of Anvil 1001

page_text: I, WILLIAM GREEN of 5 Mount Pleasant, Clerkenwell, Optician do hereby
declare the nature of my Invention for "AN IMPROVED COMBINED CLINOMETER
AND PRISMATIC COMPASS" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
This Invention has for its object an improved combined clinometer and
prismatic compass.
In my improved combined instruments, the compass card and the clinometer
card appear upon opposite faces of the instrument. The prism, by the aid of
which the angles are read, is mounted upon a block, which is pivotted to the frame
in such a manner that it may be turned round so as to carry the prism from one
face of the instrument to the other. A catch is provided to retain the block in
either position. Thus the same prism is employed for reading the angles whether
on the compass card or the card of the clinometer.
The frame carrying the sight wire is so jointed to the main frame as to admit of
its being turned through an angle of 270 degrees, it may thus either be laid down
flat and parallel to the card when out of use or it may be erected for use with the
compass card or again it may be reversed for use with the clinometer.
A friction brake is provided to check the vibrations of the compass card. To
raise the compass card off its pivot when not in use, a lever is provided it has two
arms nearly but not quite at a right angle. The longer arm is perforated at its
end and the pivot passes freely through it, and this end of the lever lies beneath
the compass card.
The other or shorter arm of the lever has a pin fixed upon it which projects
through a hole in the case of the instrument and receives a small nut having a
milled edge adapting it to be turned by the fingers. Sometimes a sliding arrange-
ment is used to raise the lever instead of milled head.
When the nut is screwed up tightly, in consequence of the form of the lever its
longer end is raised towards the point of the pivot, and it then lifts the card off
the pivot, but when the nut is loosened then the lever by its own weight drops to
the lower end of the pivot clear of the compass card.
Thus as has been explained in my combined instrument, the clinometer and the
compass card are observed upon opposite faces of the instrument, whereas, in all
combined instruments of the sort heretofore in use, the compass and the clinometer
has been observed on the same face of the instrument.
In some cases the clinometer card has been enclosed in a separate box, which
when required for use has to be placed over the box of the compass card, an
arrangement which has this disadvantage amongst others, that the instrument is
in two parts which have to be detached for use, and the moveable part is liable
then to be lost or to receive injury.
In other cases the clinometer card has been mounted above the compass card on
the same face of the instrument, and has an opening in it through which the
compass card can be observed.
This arrangement has the disadvantage that time is unavoidably lost in securing
the clinometer card before the compass can be used. The latter card also is
necessarily deep down in its box, which in some cases renders it difficult for
sufficient light to reach the card to admit of its being easily read; and further, the

page_text: clinometer card and the compass card being on different levels an adjustment of
the distance of the observing prism is necessary when passing from observations
with one card to that with the other.
In order that my said Invention may be fully understood and readily carried
into effect I will proceed to describe the Drawings hereunto annexed.
Figure 1 is a side elevation of a combined clinometer and prismatic compass as
it appears when folded for travelling.
Figure 2 is also a side elevation, and it represents the instrument as set up for
use as a prismatic compass.
Figure 3 is again a side elevation of the instrument and here it is shown as
arranged for use as a clinometer it will now be held with the sight flap horizontal.
Figures 4 and 5 are elevations of the instrument and
Figures 6 and 7 are plans.
Figure 8 is a transverse vertical section.
A is the outer frame of the instrument, it has in it two glazed apertures, one on
either side marked A' A². A¹ is a window through which the compass card can be
seen immediately beneath, and A³ is another similar window at which the
clinometer card similarly appears.
The case contains a central partition A³ which carries the pivot for the compass
card B and also one end of the axis C¹ of the clinometer card C. The partition is
lightened by perforations.
D is the ordinary prism and prism holder with the sight notch D', it is hinged
to a sliding piece at D2 carried in the block E. These arrangements admit of
focussing and they are as is usual except that the block E instead of being fixed
to the case as at present, is mounted upon a pivot E¹ and is capable of being
turned over to transfer the observing prism from one side of the box or case A to
the other side.
F is a catch which serves to retain the block E in either of these positions. The
catch is jointed to the intermediate partition of the case; and it carries a
projecting pin or tooth which drops into a hole provided to receive it in the
block E. There is one hole on either side of the block.
G is a flap carrying the sight wire; this is as is usual except that it is so jointed
to the case as to admit of a larger range of motion, so that it may, as the Drawing
represents, be made to project from either the front or the back face of the
instrument.
When the compass card is not required for use it is lifted from its pivot by
means of the lever H which is shown separately at Figures 9. One limb of this
lever is provided with a tail or stem which receives a nut H' and by screwing up
this nut the tail of the lever is drawn outwards from the case, with the result that
the extremity of the lever which surrounds the pivot and is beneath the compass
card is raised, and the compass card also is lifted whereby unnecessary wear of the
pivot is avoided.
In place of the nut a slider may be applied to act upon the stem or tail of the
lever H.
I is a stud which when pressed upon deflects the spring I¹ inwards and causes a
slight friction upon the periphery of the compass card, and so aids in bringing it
more rapidly to rest.
The arrangements in respect to this friction stop are as usual. A stop may also
be provided to hold the clinometer card stationary when it is not required for use.
In some cases in place of arranging the sight flap so that it may serve for use
on both sides of the instrument, I arrange a separate short sight flap for use with a
prismatic compass, as is shown by the Figure 10.

page_text: Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed I declare that what
I claim is
First. A combined clinometer and prismatic compass with the two cards on
opposite faces of the instrument, and the observing prism so mounted that it may
be set to observe either one or other of the cards.
Second. The arrangement for lifting the compass card from its pivot, sub-
stantially as shown and described.