An Improved Altazimuth, applicable also for Use as a Clinometer.
Year: 1895

page_text: Date of Application, 6th Sept., 1895-Accepted, 2nd Nov., 1895
ELM ST EUIRTUALION.
An Improved Altazimuth, applicable also for Use as a Clinometer.
DAVID WILLIAM BRUNTON Aspen Pitkin County Colorado U.S.A. Mining
Engineer 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 :—
The object of this invention is to provide an apparatus or instrument by means
of which surveyors and others may take sights above and below the horizontal.
In the ordinary surveying compass provided with sights, it is not possible to take
the reading of the needle while looking through the sights at a distant object and
heretofore in order to take compass bearings it has been necessary to provide the
instrument with a tripod or Jacob's staff, so that it could be first sighted upon the
object and then the reading taken afterwards; and when used as a hand instrument
two observers were required, one to sight the instrument on the object whose
bearing was to be taken, and the other to take a simultaneous reading of the
needle. The simultaneous sighting and reading of a compass can also be attained
by an instrument known as the prismatic compass, but its use has been extremely
limited and the results obtained very inaccurate, because, first, the prismatic
compass will only take sights on or near a level with the instrument, and, second,
the weight of the needle is greatly increased and its accuracy impaired by carrying
a large circular card, and, third, the prism obscures the light and only indifferent
results can be obtained reading by candle light underground. So far as I am
aware, no small portable instrument for taking both horizontal and vertical angles
has hitherto been produced. Instruments for taking vertical angles and clinometer
readings are in general use, but no successful attempt, so far as I am aware, has
yet been made to combine them with a compass or other instrument for taking
horizontal angles.
In my device, which 1 designate a pocket transit, and wherein I dispense with
the use of a Jacob's staff or a tripod, I have provided means for taking both
horizontal and vertical angles, and for obtaining clinometer readings, and have
made the instrument sufficiently small and light to be carried in the vest pocket.
The instrument comprises a casing containing a magnetic compass, an adjustable
sight for use in horizontal and vertical readings, a lid or cover hinged to the casing
and provided on its inside with a mirror and a sight-line, and a bubble tube
provided with a vernier. The sides of the casing and lid are made flat, so that the
instrument may be used as a clinometer.
Having thus stated the principle of my invention, I will proceed to set forth the
best mode in which I have contemplated applying that principle, and will then
particularly point out and distinctly claim the part or improvement which I claim
as my invention.
In the accompanying drawings illustrating my invention, in the figures of which
like parts are similarly designated, Figure 1 is a plan view of the parts open and
Fig. 2 is a vertical section showing the parts in full lines arranged for taking
vertical readings, and also showing the parts in dotted lines for taking horizontal
readings. Fig. is a transverse section of the instrument closed, taken in the plane
of line - Fig. 1 and looking towards the left, aud Fig. 4 is a perspective view
of the bubble tube, vernier area, and operating crank, on a larger scale.
a is the casing which may be of aluminium or other substance or material of
appropriate character, to receive the needle of a magnetic compass, which needle
may be mounted in any usual manner, and be provided with the locking lever c

page_text: which as here shown projects up from the face of the casing at c¹ so as to be
operated by the closing of the lid d.
e is a degree circle for the compass, suitably divided and subdivided, the drawing
showing the circle divided into multiples of five. The lid or cover d is provided
on its inside with a mirror f in the center of which is the sight line 9, which
terminates at its inner end in a sight opening h, the said lid or cover being hinged
to the casing at i in any suitable manner. At the opposite side of the casing is
arranged an adjustable folding sight which may be hinged to the said casing at k
in any suitable manner. This folding sight is provided with a longitudinal slot / in
line with the sight-line g. The outer end of this folding sight is provided with a
hinged piece m which has a sight opening n therein, the said hinged piece being
adapted to be turned up at right angles to the sight as indicated in the full lines
in Fig. 2. This hinged and folding sight is of a length sufficient to be folded
within the casing and over the glass face a¹ of such casing. Within the bottom of
the casing is arranged a post o eccentrically thereof, and upon this post is pivoted
an arm which is slotted at p to encircle the base of the needle and work around
it. This arm terminates in a vernier p2 which is arranged over an appropriate
vernier scale g.
The opposite end of this arm is supplied with a bubble tuber.
The post o extends through to the rear side of the casing and is provided with a
crank lever or handle, by means of which the bubble tube and its connected
vernier may be adjusted to obtain levels.
Some of the uses of this instrument may be stated as follows: By placing the
folding sight at right angles with the top of the casing as indicated in dotted lines
in Fig. 2, and the lid d at an angle of one hundred and thirty-five degrees from the
top of the casing, and holding the instrument firmly, in the two hands, in a hori-
zontal position, at about the height of the waist, an observer, by looking directly
down into the mirror, will see the objects in front of him reflected therein. The
instrument may be accurately sighted at any one of these objects by bringing it in
line with the sight line y, bisecting the opening or slot in the folding sight, aud,
at the same time, the needle reading may be accurately taken by the same
observer.
By varying the position of the lid or cover and the folding sight, courses may be
taken to objects situated at almost any angle above or below the observer. To take
vertical angles, the instrument is held edge up, and the lid or cover is set to
approximately an angle of forty five degrees with the top of the casing, and the
folding sight turned outwardly untill it is parallel with the top of the casing, and
its hinged end m then turned outwardly, at right angles to the sight, all as indicated
in full lines in Fig. 2, and then by holding the lid or cover with the left hand, and
the casing between the fore finger and thumb of the right hand, and placing the
end m close to the eye so as to look through the opening therein, sights can be
taken through such opening, and the opening in the lid or cover, while at the
same time the bubble tube can be plainly seen in the mirror.
In measuring vertical angles, above and below the horizontal, it is only necessary
then to turn the crank s on the bottom of the instrument, with the second finger of
the right hand so as to bring the bubble to the centre of the bubble tube, after
which the cover may be opened and the reading taken from the vernier circle on
the bottom of the casing.
Inasmuch as the cover and the casing are of exactly the same width and flat on
their sides, it is obvious that when the lid is opened so that it is parallel with the
face of the casing as in Fig. 1, by applying the instrument edgewise to an object,
the instrument may be used as a clinometer.
Other uses of this instrument will readily suggest themselves to those skilled in
the art, but the above are deemed to be sufficient to indicate its general purposes
and usefuluess.
I am well aware that prior to my invention surveying instruments with fold.ng
sights have been made, and also instruments for taking vertical angles, and hence
I do not claim either of these instruments, separately considered, but

page_text: 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
claun is:-
1. An improved altazimuth applicable also for use as a clinometer having a body
provided with a magnetic compass, the mirror lined lid or cover provided with a
sight line, and a folding sight provided with a longitudinal sight slot, combined as
and for the purpose described.
2. An improved altazimuth applicable also for use as a clinometer comprising a
body having a bubble tube vernier and scale, a folding sight provided with a hinged
end, having a sighting aperture, and a mirror lined hinged lid or cover, having a
sight opening, substantially as, and for the purpose, described.
3. An improved altazimuth applicable also for use as a clinometer provided with a
bubble tube having a vernier arm and an operating crank arranged on the outside
of the instrument, an adjustable mirror lined lid or cover having a sight opening
and a folding sight, provided with a right-angled end, having a sighting aperture,
substantially as described.
4. An improved altazimuth applicable also for use as a clinometer comprising a
magnetic needle, a bubble tube, a movable arm arranged eccentrically within the
casing of the instrument, and slotted to surround the post of the needle, whereby
the bubble tube may be rotated through an arc of one hundred and eighty degrees
without interference with the needle post, a vernier on said arm, and a crank
arranged on the outside of the casing and adapted to be actuated by a finger of the
hand holding the instrument, substantially as described.
5. In an improved altazimuth applicable also for use as a clinometer, the com-
bination of the body or casing, the mirror lined lid hinged thereto, the folding
sight jointed to said body and provided with a hinged end, a bubble tube pivoted
within said body and connected with a vernier arm and its scale, and an external
crank for adjusting the bubble tube, substantially as described.
6. In an improved altazimuth applicable also for use as a clinometer, a casing
containing a magnetic needle and a degree circle, a mirror-lined lid or cover
hinged to said casing and provided with a sight line, and a sight hinged to said
casing opposite the lid, and adapted to be folded in between the casing and cover
or lid, substantially as described.
7. An improved altazimuth applicable also for use as a clinometer comprising a
casing and a hinged lid of the same width, and having flat sides, and an adjustable
bubble tube within the casing, whereby the instrument may be used as a clinometer,
substantially as described.
Dated this Second day of August 1895,
DAVID WILLIAM BRUNTON,
Aspen Pitkin Co. Colorado.