Improvements in Apparatus for Determining a Ship's Bearings and Course.
Year: 1891

page_text: Date of Application, 7th Dec., 1891
Complete Specification Left, 7th Sept., 1892-Accepted, 7th Dec., 1892
Improvements in Apparatus for Determining a Ship's Bearings
and Course.
I, THOMAS WILLIAMS of Tyddyncoed, Bodvean, Pwllheli, in the County of
Carnarvon, Master Mariner, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in apparatus for determining a ship's
bearings and course.
In carrying it into effect I mount a compass card upon a disc which is carried
by gimbals. The card is centred upon a suitable point so as to be capable of being
revolved.
A pillar of a suitable height is mounted on the centre of the said card. The top
of the pillar has fitted to it in the vertical plane a semi circular plate the straight
The latter is
edge of which is horizontal and is above the semi circular one.
suitably graduated starting from 0° in the centre and terminating. in 90° at both
ends. A circular dial having the hours one to twelve marked thereon is fixed in
the horizontal plane upon the top of the said plate.
At foot of the pillar a pointer is placed which can be revolved around the
compass card, and a suitable clamp is provided to keep it in the desired position.
Another pointer is placed upon the card which is somewhat shorter than the one
last mentioned. This pointer has a movement of a quarter of a circle. The card
is marked from zero to 45° on each side.
On the top of the pillar, and secured to the dial before mentioned, there is a
vertical pin upon which revolves a short pillar, to the bottom of which a pointer is
attached. This pointer points to the figures indicating the hours of the day
upon the before mentioned dial. Upon this pillar is mounted a telescope which
may be used with or without lenses as desired, cross wires being placed inside in
the usual way. Upon the telescopic tube are affixed two vertical projections, a
slit being placed in the one nearest the eye and a vertical wire in the other. The
purpose of the wire is for the sun to throw its shadow on the slit in the other end.
Another application of this invention and one to which I attach great importance,
is that by it I am able to affix a portion of the before mentioned apparatus to be
used in connection with the ordinary magnetic compass, to do which I make an
aperture in the centre of the glass over the ordinary compass card; and to the foot
of the pillar already mentioned, I attach a pointer which passes underneath the
glass and over the compass card which pointer is capable of being revolved around
with the upright pillar and telescope arrangement.
Dated this 7th day of December 1891.
PHILLIPS & LEIGH,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Determining a Ship's Bearings
and Course.
I, THOMAS WILLIAMS, of Tyddyncoed, Bodvean, Pwllheli, in the County of
Carnarvon, Master Mariner, 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 :—
This invention relates to improvements in apparatus for determining a ship's
bearings and course.
In carrying it into effect I mount a compass card upon a disc which is carried
by gimbals. The card is centred upon a suitable point so as to be capable of being
revolved.
The
A pillar of a suitable height is mounted on the centre of the said card. The
top of the pillar has fitted to it in the vertical plane a semi circular plate the
straight edge of which is horizontal and is above the semi circular one.
latter is suitably graduated starting from 0° in the centre and terminating in 90°
at both ends. A circular dial having the hours one to twelve marked thereon is
fixed in the horizontal plane upon the top of the said plate.
At the foot of the pillar, a pointer is placed which can be revolved around the
compass card and a suitable clamp is provided to keep it in the desired position.
Another pointer is placed upon the card which is somewhat shorter than the one
last mentioned.
On the top of the pillar and secured to the dial before mentioned, there is a
vertical pin upon which revolves a short pillar to the bottom of which a pointer is
attached. This pointer points to the figures indicating the hours of the day, that
is upon the before mentioned dial. Upon this pillar is mounted a telescope which
may be used with or without lenses as desired, cross wires being placed inside in
the usual way. Upon the telescopic tube are affixed the usual sight vane and a
telescope.
Another application of this invention and one to which I attach great importance,
is that by it I am able to affix a portion of the before mentioned apparatus to be
used in connection with the ordinary magnetic compass, to do which I make an
aperture in the centre of the glass over the ordinary compass card, and to the foot
of the pillar already mentioned I attach a pointer which passes underneath the
glass and over the compass card which pointer is capable of being revolved around
with the upright pillar and telescope arrangement.
ADVANTAGES AND UTILITIES OF THE INVENTION.
1. The instrument can be used in conjunction with the ordinary magnetic
compass in the following manner. Its vertical axis is continued downwards through,
and there carries a pointer adapted to move over, the markings on the compass
card. As this pointer is aligned with a telescope carried on the top of the vertical
axis, the bearing of any object which is taken through the telescope will be shewn
by the pointer on the compass card.
2. The error and deviation of the compass can be ascertained night or day by
reference to objects in the heavens.
3. The error and deviation can be ascertained by means of the sun without
azimuth tables.
4. The instrument will shew either the true or the magnetic course steered.
5. It will shew the bearing of any object either by compass, true, or magnetic,
for the purpose of finding the ship's position when sailing along a coast.
6. It can be used in its own case, independently of the compass for any of the

page_text: purposes referred to in the preceding paragraphs, if it is set at any convenient
part of the deck parallel with the keel.
7. The dumb card can be set to shew the course the ship is to steer, so that no
mistakes shall be made when the officers are relieving each other.
In order that my invention and the means by which it is to be carried into
practical effect may be thoroughly understood, I will describe it in detail, referring
in so doing to the accompanying figures which are to be taken as part of this
Specification and read therewith.
Fig. 1 is a side elevation, partly in section, illustrating my invention made up as:
a complete and independent instrument.
Fig. 2 is a sectional plan taken on the line A-B of Fig. 1.
Fig. 3 is a side elevation of the half circle or latitude plate, hour dial and their
pillar.
Fig. 4 is a perspective view of the telescope attachment.
Fig. 5 is a sectional side elevation of my invention made up as an attachment to
be used in connection with the ordinary magnetic compass.
Referring to Figs. 1 and 3, C is the case of the apparatus or instrument.
D is
the compass bowl. It is suspended from pivots on the gimbal ring d, the latter
being pivotted in the top of the case in the well known way. The compass bowl
is weighted so as to automatically maintain its top plate or cover in the horizontal
plane. E is a lever having its fulcrum at e. It is actuated in either direction by
the vertical screw e for the purpose of preventing or permitting the bowl
swinging.
F is a vertical pin standing up from the centre of the top plate or cover of the
bowl, to which it is made fast. It is provided with an antifriction roller. The
latter is kept in position by any suitable device, e.g., by a screw which enters
the pin Faxially from the top. A radial line and the words "ship's head "
are marked upon one side of the edge of the bowl to secure the correct placing of
the instrument. G is a circular plate (hereinafter called the compass plate). It
fits over the roller (about which it can be freely turned by the knobs g) and
rests upon the top plate or cover of the bowl within the raised edge ring of the
latter. This plate has a compass g' set out on it by points and degrees counting
from N. to 180° E. and from N. to 180° W. as well as vice versa; and in addition
thereto, a scale g for the variation each side of N. from 0 to 45°. 03 is a pointer.'
It projects radially from a ring g' which in its turn is held to the compass plate
but in such a way that it can turn freely about the roller f. The pointer ³ therefore
moves about the vertical axis of the instrument.
H is a socket or hollow pillar fitting over the roller just loosely enough to be
turned freely about it. The pin F with its roller are of a sufficient height to
support and keep the socket H together with the parts that fit into it, as herein-
after specified, vertical. The top of the ring 9 is the seat of the socket H, and
suitable provision is made by which the latter can be connected to the compass
plate. The device illustrated for effecting this connection consists of a bolt h
which can be moved vertically in either direction in a V shaped groove in the
outside of the socket H by a thumb bit. It engages in a socket in the top of
the ring gas shewn in Fig. 1. h2 is a clamping screw working through a slot in
the bolt and in a threaded hole in the side of the socket.
I is a pointer fast to the bottom of the socket, and of a proper length and shape
for travelling over the compass y' and clearing the knobs g.
J is a pillar adapted to fit into the top of the socket H." It has a vertical notch
cut down through its centre from the top deep enough to receive a semicircular
plate or half circlej which is pivotted by a pin to the top of the pillar. It is
marked with a scale of degrees of N. and S. latitude. is a sight hole in the side
of the pillar J through which the scale can be read. It is provided with a central
mark x. is a clamping screw by means of which the plate j can be set to the
latitude required. This plate ; and the pointer I are in the same vertical plane.
A suitable device, e.g., a stud j³ on the pin and a corresponding notch in the top

page_text: of the socket H on one or opposite sides of both pin and socket, is provided to
facilitate the fixation of the pin in the proper position.
K is a dial having the hours, divided into 5 minute spaces, marked on it for
both A.M. and P.M., and k is its pointer moveable about a central and vertical
pin k¹.
L is a tube fitting over the pin 4. is a bar pivotted to the top of the tube in
such a way that it can be moved in either direction in the vertical plane. This
bar is fitted with the well known sighting devices l', so constituting a sight vane,
and also with a telescope . This latter may be used with or without lenses, as
desired. Suitable provision is made for easily fixing the telescope in the proper
position, that is, aligned with the pointer K, e.g., by means of a stud and slot
device 18.
When the latitude half circle ; and the hour dial K are not required, a tube 1*
of a convenient length and adapted to receive the tube L in its top end and to fit
into the socket H by its bottom end, is used. It, as well as the parts into or on to
which it fits, are provided with suitable devices 1 for holding it in the proper
position relatively thereto.
A lamp may be fitted in the socket M for night use of the apparatus.
Referring to Fig. 5, N is the compass card; n, the compass bowl, and n¹, the
glass or other top of an ordinary magnetic compass to which the instrument is held
by clamping nuts n². O is a pointer fixed, heneath the top n', to a downward
extension of the pin F. The indicating end of this pointer is bent vertically down-
wards as far as the edge of the card N. The inside face (not shewn in the figures).
of this end has a vertical black line on a white ground, or equivalent mark, to
enable a correct bearing to be taken. o is a sight hole through which the bearing
can be read. P is a removeable bar held to the pin F in any convenient way.
p is a radial slot through which the compass plate can be seen.
The outer end of
this bar carries a radial indicating line and the words "ship's head" in the same
way and for the same purpose as does the raised ring before described.
INSTRUCTIONS FOR USE.
If true course is required the variation pointer is to be placed on the north point
of the card.
If magnetic course is required, it must be put on degrees as per chart. The
telescope and sight vane are to be set to the time on the dial to the nearest minute
(apparent time at ship). Set the latitude of the ship at the pointer, and turn the
instrument round until the sun's shadow will be in the centre of both ends of the
vane. The difference between the ship's head by compass and the ship's head by
the dumb card will be the error or direction according to the setting of the instru
ment for true or magnetic course. If the sun is not sufficiently strong (or clear)
for the shadow to be seen on the vane, the telescope can be used instead.
If azimuth tables are used, the upper part of the instrument must be dis-
connected from the card. The pointer attached is put on the degrees (sun's true
bearing) on the edge of the card as taken from Burwood's tables. Then move the
upper part of the instrument round until the sun's shadow will cut the centre of
the vane, or direct the sight through the telescope towards the sun.
ship's head by the card will show the true course the ship is steering.
Then the
It
If the bearing of any object is required by compass, both parts of the instrument
are to be connected. Then set the telescope on twelve o'clock on the dial.
will be then in a line with the pointer inside the bowl. Next direct the sight
through the telescope and turn the instrument round until the object is seen cutting
the crossing of the wires inside the telescope. The pointer inside the bowl will
show the bearing by compass.
If magnetic bearing is required, disconnect the instrument and turn the telescope
round in the opposite direction to twelve o'clock on the dial. It will then be in
line with pointer attached to the upper part of the instrument. Then set the card

page_text: on the ship's head, allowing for deviation east or west as the case may be, and
direct the sight through the telescope towards the object. The pointer will then
show the bearing.
If true bearing is required, set the card on ship's head, allowing for variation
and deviation.
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. The operative combination of the herein before described devices, as the same.
is illustrated in Fig. 1, and as herein before specified for the purposes set forth.
2. The modification or attachment as and for the purpose described and as
illustrated in Fig. 5.
3. The general construction of the improvement in apparatus for determining a
ship's bearings and course, substantially as set forth.
Dated this 7th day of September 1892
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.
Agents for the Applicant.