Improvements in Compasses, and in Binnacles and Course Correcting Instruments Employed in connection therewith.
Year: 1895

page_text: Date of Application, 30th Mar., 1895
Complete Specification Left, 30th Dec., 1895-Accepted, 14th Mar., 1896
TROYIDIONAL
Improvements in Compasses, and in Binnacles and Course Correcting
Instruments Employed in connection therewith.
I, GEORGE WILSON HEATH of Observatory Works, Crayford in the County
of Kent, Scientific Instrument Maker, do hereby declare the nature of this
invention to be as follows:-
:-
The first part of my improvements relates to that kind of compass card in which
the aluminium ring is connected to the centre by means of silken spokes, and it
consists as follows:-Instead of making each separate spoke, or at most two spokes,
of one piece of silk as heretofore, I make the whole of the spokes of one continuous
piece of silk cord or of several pieces of such cord joined together into one con-
tinuous length; and instead of fixing this silk cord at the centre by merely twisting
it round the central spoke holes and securing the ends in place by means of shellac
or other adhesive material I pass the silk cord alternately from the periphery of
the card to the centre, and from the centre to the periphery radially round the
entire circumference passing through and in some cases tying it in suitable holes
in the centre and aluminium ring respectively and in some cases winding it or tying
it round the latter. The silken spokes thus formed are preferably placed at equal
distances radially round the centre and there may be any required number of such
spokes in one compass card.
Furthermore as an additional security the spokes where they are connected to
the centre or to the ring may be fixed with shellac or other suitable adhesive
material if preferred.
In order to attach the compass needles to the card I not only thread the attaching
cord or cords through the hole at the end of each needle, and fix it with shellac or
other suitable adhesive material as heretofore, but I twist or tie the cord to the end
of each needle.
It will be understood that in the arrangements above described the silken cords
forming the spokes, and the attachments for the compass needles are in no way
dependent upon the shellac or other similar substance to keep them in position, as
that is effected by the twisting or tying of the silk cord itself to the part with which
it is connected.
The second part of my improvements relates to the course correcting or azimuth
instrument very commonly used with these and other compasses, and which is
sometimes placed over the compass card, and sometimes separately in a box by its
side. My improvements under this head consist as follows:-In the dials of
instruments of this kind in which the east and west points are reversed 1 employ a
supplementary scale of degrees placed at the inner edge of the outer ring of the
dial, and I use this supplementary scale for adjusting the dial in the outer ring to
the variation or error of the compass. Instead of the sight vane commonly used in
instruments of this kind I employ a conical sight vane provided at the smaller or
eye end with a sight hole for observation through the axes of the conical sight
vane, and in some cases with an external slit through which a celestial or other
object can be seen and brought roughly into line with a collimation wire or other
similar device mounted on the larger end of the conical vane; which end may also
be provided with one or more collimation wires at or near its axis. I also some-
times place a chamber under the dial of a course correcting instrument, and place

page_text: therein a more or less viscous fluid whereby the instrument is steadied quickly. I
also employ in connection with the instrument a clamp attachment for holding the
lead weight, a lamp, fitting into a socket at the side of the instrument, and a
suitable clinometer.
The lamp above mentioned is preferably provided with a tall conical chamber
and an outer cover with side and top openings to allow of the escape of smoke;
and this lamp may also be advantageously used as a binnacle lamp.
The third part of my improvements relates to means for correcting the compass
card to the true point as given by the course correcting instrument, and for this
purpose I place within the binnacle stand transverse magnets fixed on shoulders
and held in position by set screws or other suitable means.
Dated this 30th day of March 1895.
Improvements in Compasses, and in Binnacles and Course Correcting
Instruments Employed in connection therewith.
I, GEORGE WILSON HEATH of Observatory Works, Crayford, in the County
of Kent, Scientific Instrument Maker, 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 first part of my improvements relates to that kind of compass card in which
the outer ring is connected to the centre by means of silken or other similar spokes,
and this part of the invention is illustrated in Figures 1 to 5 inclusive of the
accompanying two sheets of drawings, in which
Figure 1 is a plan of such a compass card, Figure 2 an under view of same,
Figure 3 a section on lines X-X of Figures 1 and 2, and
Figures 4 and 5 upper and under side views respectively, to a larger scale, of the
centre-piece C shown in Figure 1.
Instead of making each separate spoke, or at most two spokes, of one piece of
silk as heretofore, I make the whole of the spokes A of one continuous piece of
silk or other cord, or of several pieces of such cord joined together into one con-
tinuous length; and, instead of fixing this cord at the centre by merely twisting
it round the central spoke holes, and securing the ends in place by means of shellac
or other adhesive material, I pass the cord A. alternately from the periphery of the
card, that is to say from the ring B, to the centre-piece C, and from thence to
the periphery, radially backwards and forwards round the entire circumference,
passing it through, and in some cases tying it in holes D in the centre-piece C, and
holes E in the ring B. The spokes thus formed are preferably placed at equal
distances radially round the centre; and there may be any required number of
such spokes in one compass card.
The cord A may be merely threaded through the holes in the ring B and centre-
piece C, and the two ends then tied together, or otherwise secured; but I prefer
to apply the cord in the manner shown in Figures 1 to 5, that is to say the cord A
is passed downwards for example through No. 1 hole in the centre-piece C, then
up round the edge of such centre-piece and back again through the same hole (see
Figure 4), the fold being drawn tight; then the cord is passed upwards through
No. 2 hole of the centre-piece (see Figure 5), down round the edge and up again
through the same hole, and the fold drawn tight; then the cord is passed outwards
through No. 2 hole in the ring B, round the upper edge of that ring, back through

page_text: the same hole and the fold drawn tight; the cord is then passed along the outside
of the periphery of the ring B to No. 3 hole therein, and inwardly through such
hole, round the upper edge of the ring, and again through the same hole in the
same direction, and the fold drawn tight; then the cord is passed to No. 3 hole in
the centre-piece C, downwards through the same twice, then to No. 4 hole in the
centre-piece, twice through that, then back twice through No. 4 hole in the
periphery of the ring B, then twice through No. 5 hole of the ring, and so on
round the entire circumference of the card, until the cord at last passes through
No. 1 hole in the ring B, and the two ends of the cord thus brought into juxta-
position are tied together or otherwise secured.
The annular card or paper F with the points of the compass marked thereon is
then put in place in the usual way as shown in Figure 1.
.
As an additional security the spokes, where they are connected to the centre-
piece C or to the ring B, may be fixed with shellac or other suitable adhesive
material if preferred.
In order to attach the compass needles G to the card I not only thread the
attaching cord or cords H (see Figures 2 and 3) through the hole at the ends of
each needle, and fix it with shellac, but I also tie the cord to the end of each needle
as shown at I for example.
It will be understood that in the arrangements above described the cords forming
the spokes, and the attachments for the compass needles are not dependent upon
the shellac or other similar substance to keep them in position, as that is effected
by the twisting, folding, or tying of the cord itself on or to the part with which it
is connected.
The second part of my improvements relates to course correcting or azimuth
instruments, such as those known as Bain and Ainsley's course correctors for
example, very commonly used with compasses, and which is sometimes placed over
the compass card, and sometimes separately in a box by its side. My improve-
ments under this head are illustrated in Figures 6, 7, 8 and 9 of the drawings, in
which Figure 6 is a sectional elevation, Figure 7 a sectional plan taken on
line Y-Y of Figure 6, of such a course correcting instrument with my improve-
ments applied thereto, and Figures 8 and 9 detail views.
J is the gimbal ring of the instrument hung on pivots K fixed in the side L of
the containing box, or in or to any other suitable support. M is the frame of the
instrument hung on pivots N fixed in the gimbal ring J. This frame M carries
the outer ring P of the dial of the instrument, the said ring being free to turn in
the frame M. Qis the inner dial which is free to turn in the outer ring P, so that
both the ring P and the inner dial Q can be adjusted to any desired position with
reference to each other, and to the frame M, the inner dial Q being clamped in
position in the ring P by clamping screws S, and both the dial Q and ring P to
the frame M by the clamping nut R screwed on the centre boss M1 of the
frame M. All these arrangements are such as are usually employed, and do not
form features of my invention.
In
In the dials of instruments of this kind in which the east and west points are
reversed I employ one or more supplementary scales of degrees T at the inner edge
of the outer ring P of the dial; and I use these supplementary scales for adjusting,
the inner dial in the outer ring P to the variation or error of the compass.
Figure.7 for example the north point of the dial Q is shown set to 19° on the
scale T corresponding to that amount of variation or error of the compass to the
west of the true north.
Instead of the sight vane commonly used in instruments of this kind I employ a
conical sight vane U provided at the smaller or eye end with a sight hole Ū 1
(see Figure 8), provided if desired with a coloured glass shade U 2, for observation
through the axis of the conical sight vane U, and in some cases an external slit U 3
may be provided through which a celestial or other object can be seen and brought
into line with a collimation wire U 4, or other similar device mounted on the larger
end of the conical vane U (see Figure 9). The conical vane U may also be

page_text: provided with one or more collimation wires U5 at or near its axis, and it is
hinged on the upper end of the stem U 6 which fits at its lower end into a hole or
sccl et in the centre M' and acts sometimes as a shadow pin in the usual way.
I sometimes provide a double pointer V secured to the stem U 6, and placed in
the same plane as the axis of the conical vane U. One end of this pointer bears
the word "bearings" and is intended to indicate on the dial the bearing of an
object viewed through the sight vane when the said object does not cast a shadow,
such as a star, a light, a landmark or other known object; and the other end of
the pointer bears the words "dull sun" and is intended to indicate the bearing of
the sun when the latter, although visible through the sight vane, is so obscured
that it fails to cast a shadow on the dial by means of the ordinary shadow pin, or
by the stem U 6.
I also sometimes place a chamber W below the dial of a course correcting
instrument, and place therein a more or less viscous fluid, such as glycerine or
castor oil for example, for the purpose of steadying the instrument, and stopping
its oscillations more quickly than can be effected by a weight alone. This result
is produced by the sluggish action of the viscous fluid in returning to its normal
position in the chamber W when the latter is displaced by an oscillation of the
instrument, the said sluggish action counterbalancing as it were the more lively
movements of the instrument due to the shortness of its radius of oscillation.
In connection with a binnacle lamp, or a lamp for illuminating a course correcting
instrument I employ the arrangement of chimney shown in Figures 10, 11 and 12
of the drawings for the purpose of preventing the entrance of currents of air into
the body of the lamp which are liable to extinguish the flame.
Figure 10 is a sectional elevation of the upper part of a lamp with my improved
chimney applied thereto, Figure 11 is a half external elevation of same, and a half
elevation with part of the outer cover Z4 removed, and Figure 12 is a plan of the
said outer cover Z4 and top of lamp.
Z is the upper part of the body of an ordinary binnacle lamp, Z 1 is a conical
chimney attached to the upper end of the body Z. Z2 is a cylindrical shield
surrounding the conical chimney Z, and provided with lateral openings Z3. Z4 is
an outer cylindrical cover, the lower end of which fits into the rebate Z 5 and is
provided with lateral openings Z 6. The top 7 of the cover Z4 bears on the
upper end of the shield Z 2, and is provided with openings Z8 corresponding to
the annular space between the shield Z2 and the outer cover Z 4.
By this arrangement currents of air striking against the outside of the cover Z 4
are prevented from entering the chimney 1 so as to produce down draughts
therein, because the annular passages formed by the chimney Z¹, shield Z2 and
outer cover Z4 offer so much resistance to the entrance of air that the velocity of
the latter is practically reduced to nothing before the air can reach the chimney;
but free exit is allowed for the escape of the products of combustion from the body
of the lamp through the annular passages and openings in the direction shown by
the arrows in Figures 10 and 11.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. In a compass card in which the outer ring is connected to the centre by
means of cord spokes, making such spokes of a continuous length of cord threaded
through holes in the outer ring and centre, substantially as described.
Second. In a compass card in which the compass needles are supported from the
outer ring by cords, securing the said needles to the cords by passing the said
cords through the eyes of the needles and tying the same therein, substantially as
described.
Third. In a course correcting, or azimuth instrument the employment of one or
more supplementary scales of degrees placed at the inner edge of the outer ring of
the dial, as and for the purpose described.

page_text: Fourth. In a course correcting or azimuth instrument the employment of a
conical sight vane constructed and applied substantially as described.
Fifth. In a course correcting, or azimuth instrument the employment of a
hollow chamber containing a more or less viscous fluid placed below and connected
with the dial of the instrument, substantially as and for the purpose described.
Sixth. In a course correcting, or azimuth instrument the employment of a double
pointer in connection with the stem supporting the sight vane, substantially as, and
for the purpose described.
Seventh. In a binnacle lamp, or a lamp for illuminating a course correcting_or
azimuth instrument, a conical chimney Z, a shield Z2 and an outer cover Z4
forming annular passages round the said chimney, the said shield and outer cover
being provided with openings for the escape of the products of combustion
combined and arranged substantially as described with reference to Figures 10, 11
and 12 of the drawings, and for the purpose specified.
Deted this 20th day of Donnmhan 1005
G. W. HEATH,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.
G. W. HEATH,
Per W. H. Beck,
115 Cannon Street, London, É.C., Agent.