TAK BEARINGS BY MEANS OF THE SUN & THE TIME OR THE NORTH STAR, INSTEAD OF BY MAGNETISM
Year: 1885

page_text: BETHEL MARTIN DAWES Lieutenant Colonel in the Army Osnaburgh House York
Town, Surrey do hereby declare the nature of my invention for TAKING BEARINGS
BY MEANS OF THE SUN & THE TIME OR THE NORTH STAR, INSTEAD OF BY
MAGNETISM to be as follows:-
The principle of this Compass is based upon the course of the Sun by day and
the position of the North Star by night.
To take a bearing by day. Align the time line, as indicated on the disc, on the
sun at the hour at which the bearing is taken keeping the disc in as horizontal
position as possible. The North point indicated on the disc will then point due
North and the bearing can then be taken.
When greater accuracy is required the disc can have an elevator, attached to a
revolving arm (A in plan & section) in the elevator is a slit to allow of the suns
rays to be made to correspond more exactly with the time line. It can also be
provided with a pointer B, which can be set to the direction it is desired to go, or
to be used for taking bearings.
To take a bearing by night, the North point, must be aligned on the North Star,
when the compass will be set and the bearings may be taken.
This Compass may be made in the form of a simple disc, which can be carried in
the pocket or attached to a watch chain. It can also be made to form the back or
front case of a watch; with a watch constructed to indicate the "New time" or
read twenty four hours, it will be specially applicable, as the degrees only need be
added to the dial.
I
It can also be constructed, to read with greater exactness, with the elevator
& pointer and with a spirit level attached to ensure the disc, being in a horizontal
plane, and when so constructed may be used for correcting compasses on board
ship &c.
The advantages I claim are that it is very portable, and can not get out of order.
That it is not liable to error.
And that it is not subject to outside disturbing influences which make the
magnetic compass so unreliable.

page_text: BETHEL MARTIN DAWES Lieutenant Colonel in the Army Osnaburgh House York
Town Farnboro, Hampshire do hereby declare the nature of my invention for
TAKING BEARINGS BY MEANS OF THE SUN & THE NORTH STAR, & THE TIME,
INSTEAD OF BY MAGNETISM and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
The principle of this Compass is based on the course of the Sun by day, and the
position of the North Star by night.
The instrument is constructed as follows.
A circular disc is divided into 24 hours, and into degrees as a Compass. Vide,
drawings.
To take a bearing by day, the instrument is held in a horizontal plane, with the
line indicating the time at which the bearing is taken aligned on the Sun.
XII o'clock, further indicated by an arrow head, will then point due north and
the bearing of any object can be taken.
.
The instrument may be provided with a revolving elevator to throw a shadow
or if with a slit to throw a light along the time line, also with a spirit level, to
ensure its being in a horizontal plane, for the purposes of greater accuracy.
To take a bearing by night, the North point, or XII o'clock indicated by the
arrow head should be aligned on the North Star, when the compass will be set and
the bearings may be taken.
This compass may be applied to a watch, & is particularly adaptable to the
24 hour, or "
new. time" watch and I have applied it to the latter, and in this
case, by aligning the hour hand on the Sun XII o'c, indicated also by the arrow
head, will point due North and bearings may be taken as above; the dial of course
being also divided into degrees.
The drawings herein referred to are those filed with the Provisional Specification.
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
1. That with this compass bearings can be taken by means of the Sun, the Time
and the North Star, without the aid of Magnetism.
D
2. That it is not liable to error, and from its simple construction it can not get
out of order. It is also very portable.
3. That it has no appreciable variation.
4. That acting conversely, when the North point is known, it will tell the
time by means of the sun.
5. That it is not subject to outside influences which make the Magnetic Compass
so unreliable.
Dated this 28th day of January 1886.