An Improved Solar-bearing Pointer and Sighting Arrangement for Measuring Azimuths.
Year: 1892

page_text: Date of Application, 14th Mar., 1892
Complete Specification Left, 8th Nov., 1892-Accepted, 31st Dec., 1882
PROVISIONAL SPECIFICATION.
An Improved Solar-bearing Pointer and Sighting Arrangement for
Measuring Azimuths.
I, NEWNHAM BROWNE, of 73 Cheapside, in the City of London, Fellow of the
Chartered Institute of Patent Agents do hereby declare the nature of this inven-
tion which has been communicated to me by Alfred John Loftus, of Wat
Chang, Bangkok, in the Kingdom of Siam, Captain and Hydrographer in His
Siamese Majesty's Navy to be as follows:-
My invention comprises a pointer preferably partly made of, or faced with,
porcelain or other like material, or having a central strip thereof along which is '
drawn longitudinally a lubber line. To one end of the pointer is jointed a vane
carrying a wire, or thread, stretched across it, such vaue being so jointed to the
pointer that it may lie flat in the same plane as the pointer (in which position the
wire, or thread, is in the same straight line as the lubber line) or may be placed
vertically at right angles thereto or any intermediate angle.
At, or near, the centre of the pointer is a female screw to fit on to a screw centre
the stem, of which is made to fit the hole in a compass glass, or the pointer may be
made without the screw centre, the hole in the pointer slipping over the stud
forming part of certain kinds of compass, as for instance in the "Pelorus" form of
compass.
On the end of the pointer opposite that carrying the above described vane:
is another vane lying in the same plane as the pointer and crossed by a wire"
or slip of metal or the like in the same straight line as the before' named lubber:
line.
•
That part of the pointer between the centre and the above last described vane:
carries a vertical quadrant, the two sides or walls thereof being covered in above
by a curved covering plate with a longitudinal slit which may conveniently be
about one sixteenth of an inch wide for a sunbeam to shine through. Over the
quadrant, and hinged to its upper part and of the same curve, so as to fit the
curved surface thereof, is a silvered glass or other reflector, preferably mounted in
a metal frame.
'
Recesses are provided on the under surface of the pointer for the user's fingers
to facilitate lifting the same.
"
SAR
COMPLETE SPECIFICATION.
An Improved Solar-bearing Pointer and Sighting Arrangement for
Measuring Azimuths.
NEWNHAM BROWNE, of 73, Cheapside, in the City of London, Fellow of
the Chartered Institute of Patent Agents do hereby declare the nature of this
invention and in what manner the same is to be performed, which has been com
municated to me by Alfred John Loftus, late of Wat Chang, Bangkok, in the
Kingdom of Siam, Captain and Hydrographer, in His Siamese Majesty's Navy
but now of 32 South Road, Handsworth, Birmingham, to be particularly described'
and ascertained in and by the following statement.:—
My invention comprises a pointer preferably faced with porcelain, ivory,.or.
other like material, or having a central strip thereof along which is drawn
longitudinally a lubber line. To onerend of the pointer is jointed a vane carrying

page_text: a wire, or thread, stretched across it, such vane being so jointed to the pointer that
it may lie flat in the same plane as the pointer (in which position, the wire, or
thread, is in the same straight line as the lubber line) or may be placed vertically
at right angles thereto, or any intermediate angle.
At, or near, the centre of the pointer is a female screw to fit on to a screw centre
the stem of which is made to fit the hole in a compass glass, or the pointer may be
made without the screw centre, the hole in the pointer slipping over the stud
forming part of certain kinds of compass, as for instance in the "Pelorus" form
of compass.
On the end of the pointer opposite that carrying the above described vane
is another vane lying in the same plane as the pointer and crossed by a wire or
slip of metal, or the like, in the same straight line as the before named lubber
line.
That part of the pointer between the centre and the above last described vane
carries a vertical quadrant, the two sides, or walls, thereof being covered in above
by a curved covering plate with a longitudinal slit for a sunbeam to shine through.
Over the quadrant, and hinged to its upper part and of the same curve, so as to
fit the curved surface thereof, is a silvered glass or other reflector preferably
mounted in a metal frame.
In the accompanying sheet of drawings:
Fig. 1, is an elevation, partly in section, of my said invention;
Fig. 2, is a plan of the same, and Figs. 3 and 4, are opposite end elevations.
A is a horizontal plate, preferably of brass, faced, on its upper surface, with
a piece B of porcelain, ivory, or the like having a longitudinal lubber line b.
C is a vane jointed to the plate a and having a wire, hair, or the like c stretched
across it, such vane being so jointed to the plate A that it may lie flat in the
same plane as the pointer (in which position the wire c is in the same straight
line as the lubber line) or the vane may be placed vertically, i.e. perpendicular
to the plane of the pointer as shown in dotted lines or at any intermediate
angle. D is another nearly similar vane fixed in the same plane as the pointer
and carrying a wire, slip of metal, or the like d in the same straight line as
the lubber line b. E is a quadrant fixed on the plate A of the pointer, the two
side walls thereof being united and covered in by a curved covering plate e,
through which is a fine longitudinal slit f, through which the sun may shine
and cast a line of light which falls on and coincides with the lubber line b when
the pointer is directed accurately to the sun, the quadrant forming a shaded or
partially darkened chamber within which the line of sun light is very clearly
visible. The readings are taken by looking vertically down through the vane D,
and reading the position of the wire d on the compass card, or dumb plate, beneath.
When the azimuth angle of a terrestrial object is to be observed the vane C,
is placed vertically and the observer looks through the slit f, at the wire c and
the object, the angle being read off as before.
Over the quadrant and hinged to its upper part is a curved mirror G having
a line g drawn longitudinally on its face. This mirror is mounted in a frame
and is curved so as to fit over and lie closely on the quadrant. The curve of
the mirror is that of a sphere having its centre coincident or nearly so with
that of the pointer. This mirror is for use when the sun is too much obscured
by clouds, or haze, to admit of its throwing a well defined streak of light
through the slit on to the lubber line, but is yet sufficiently visible to enable its.
position to be approximately seen. The mirror is then tilted upwards a short.
distance from the quadrant so that an observer looking at the mirror from the
opposite end of the pointer may see the sun, or an indication thereof, reflected in
the mirror.
4
1
I I
The mirror being convex reduces the blurred image of the sun to a much more.
definite figure so that the observer is able to turn the pointer so that looking over
the centre of the instrument, the image. of the sun is bisected by the line on the
reflector and thus to obtain very rapidly a fairly accurate reading of the angle.

page_text: On the under side of the pointer is a central hole H which is intended when used
with a compass having a central stud, or a dumb plate, to fit over such central stud
of the compass or dumb plate, this hole may be threaded to receive the threaded
head of a pin h which is intended for use with such compasses as have a central hole
through the glass, and the tail end of such pin h is of proper dimensions to fit into
such central hole and thus secure the correct centering of the pointer over the
compass.
My said pointer is applicable alike for obtaining solar, sidereal and terrestrial
azimuths.
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. A solar bearing pointer and sighting arrangement for measuring solar, sidereal
and terrestrial azimuths substantially as herein before described and shown in the
drawings.
2. In a solar bearing pointer, a quadrant E producing a partially darkened
chamber over the lubber line b, and the slit e for admitting a line of sunlight.
3. In a solar bearing pointer a convex mirror G, with a .central line
on a joint, substantially in the manner and for the purpose set forth.
9r mounted
4. A sighting arrangement for measuring azimuths having a quadrant E with a
slit fand a sighting vane C, substantially as described and shewn in the drawings.
5. In a solar bearing pointer and sighting arrangement for measuring azimuths,
the combination of a pointer plate A, lubber line b, vanes C and D, quadrant E,
with slit fand convex mirror G and line g thereon all substantially as described and
set forth.
Dated the Seventh day of November 1892.
NEWNHAM BROWNE,
Agent for the Applicant.