Improvements in an Apparatus for Determining the Direction of True North and the various Points of the Compass when the Time of Day is known.
Year: 1897

page_text: Date of Application, 12th May, 1897
1000
OLL
4000
PROVISIONAL SPECIFICATION.
Improvements in an Apparatus for Determining the Direction of
True North and the various Points of the Compass when the Time
of Day is known.
I, ARTHUR HILL MAURICE, of No. 1, Mortimer Road, Cardiff, Glamorganshire,
Land & Mineral Surveyor, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved method of indicating the direction of
true north without the use of a compass needle.
It is known that if a timepiece keeping correct time be held with the face lying
horizontally and the hour hand pointing to the sun, a line commencing at a point
lying midway between the hour hand and the point marked XII. on the dial and
drawn thro' the centre of the dial, lies in a north & south direction; the commence-
ment of line being to the south and its extension towards the north.
For the purpose of carrying out my invention I employ two thin discs of card-
board or any thin material of convenient size, the one disc being about an inch
greater in diameter than the other.
The smaller disc which may be about 2½ inches in diameter is divided, marked,
and lettered with the various points of the compass so as to represent an ordinary
compass plate. The larger disc is marked round the edge for a depth of half an
inch from the periphry with the divisions into hours and numerals of an ordinary
clock dial or face; and when the smaller compass plate is laid over it, with the
centres of the discs coinciding, the dial figures will appear in a ring outside the rim
of the compass plate.
In this position the discs are pivoted together through their centres in such a
manner that while always remaining in contact they are free to revolve one over
the other when moved by the hand.
Both discs may be loose on the axis or one only may be loose, and the point
marked S on the compass plate can, by revolving the discs on their axis with the
hands, be brought opposite to or in line with any division or numeral marked on
the rim of the dial plate which may be desired, the friction between the discs
tending to keep them at rest in any position they may acquire.
The discs may be made of cardboard or of thin metal plate or of any other
suitable substance. In the case of metal the clock dial divisions & numerals & the
compass markings & lettering may be stamped on or embossed. Or if plain discs
of any other material be employed the markings & lettering and ornamental
colouring may be printed on paper and then attached to the discs by an adhesive
substance.
The compass plate is divided so as to show the usual points of the compass or it
may be divided into degrees. The dial plate is divided into twelve hours, and each
hour is again divided into six, so that each division is equal to ten minutes in
time. If required the dial may be divided into minutes.
An index finger, similar to that of an ordinary timepiece may be attached to the

page_text: central axis so as to revolve independently over the clock dial. When an observa-
tion is about to be made this finger is moved over the dial to the point indicating
the correct time.
When it is required to ascertain the direction of the north or any of the points
of the compass the index finger-is first moved over the clock dial till it indicates
the correct time, and then the discs are rotated on their axis until the S point of
the compass card is exactly midway between the actual time, pointed to by the
index finger, and the numeral XII. on the dial.
The apparatus is now ready for use, and should be held with the plates in a
horizontal position and the index finger (which shows the actual time on the dial)
directed towards the sun; the compass plate then lies with its north point directed
to the true north and the other points of the compass in their proper positions.
Dated this 11th day of May 1907
* 1
Improvements in an Apparatus for Determining the Direction of
True North and the various Points of the Compass when the Time
of Day is known.
I, ARTHUR HILL MAURICE, of 1, Mortimer Road, Cardiff, Gentleman, do hereby
declare the nature of this invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and, by the following
statement:-
This invention relates to an improved method of indicating the direction of
true north without the use of a compass needle."
It is known that if a timepiece keeping correct time be held with 'the face lying
horizontally and the hour hand pointing to the sun a line commencing at a point
lying midway between the hour hand and the numeral 12 on the dial, and drawn
through the centre of the dial, lies in a north and south direction, the commence-
ment of the line being towards the south and its extension towards the north.
For the purpose of carrying out my invention I employ two thin discs of card-
board or any thin material of convenient size, the one being about 1 inch greater
in diameter than the other. The smaller disc. which may be about 2 inches in
diameter, is divided, marked and lettered with the various points of the compass
so as to represent an ordinary compass plate. The larger disc is marked round the out-
side for inch from the periphery with the divisions and figures of an ordinary clock
dial or face, and when the compass plate is laid over it with the centre of the discs
coinciding the dial figures will appear in a ring outside the rim of.the.compass plate.
In this position the discs are pivoted together through their centres in such a
manner that while always remaining in contact they are free to revolve one
the other on their axis when moved by the hand. Both discs may be loose on the
axis, or preferably one only viz., the dial plate may be loose. The point marked S
on the compass plate can, by revolving the discs on their axis with the hands, be
brought opposite to or in line. with any division or numeral marked on the dial
plate as may be required, the friction between the discs tending to keep them at
rest in any position they may acquire.
over
The compass plate is divided so as to show the ordinary points of the compass or
it may be further divided into degrees. The dial plate is divided into the usual
12 hours and each hour is again divided conveniently into six, each such, division
being equal to ten minutes in time. The dial may also be divided into minutes
if desired.
rit

page_text: An index finger similar to' and representing the hour hands of a timepiece is
pivoted on to the central axis between the two discs, being of such a length that
the finger projects about three eighths of an inch beyond the rim of the compass
plate, and it revolves independently on the axis and may by pushing it be turned
to point to any time on the dial face.
When an observation is about to be made this clock finger will be moved over
the dial to the point at that moment indicating the correct time.
When it is wished to ascertain the position' of the north or other points of the
compass the index finger is first moved over the clock dial till it indicates the
correct time, and the finger being retained in this position the discs are rotated on
their axis until the S point on the compass card is exactly midway between the
actual time, indicated by the clock finger, and the numeral 12 on the dial. The
apparatus is now ready for use and should be held with the plates in a horizontal
position and the clock finger (marking the actual time on the dial) must be directed
towards the sun. The compass plate will then lie with its N point directed to
the true north and the other points of the compass will lie in their proper positions.
Referring to the accompanying sheet of illustrative drawings, Fig. 1 is a vertical
section of an apparatus constructed according to this invention and Fig. 2 is a plan
thereof.
Two thin discs ab of cardboard or other suitable material are secured together
by a suitable pivot arrangement whereby one can be rotated relatively to the other.
The upper disc a is smaller than the disc b and is divided, marked and lettered
with the various points of the compass so as to represent an ordinary compass plate.
The larger disc b is marked round its periphery with the divisions and figures of
an ordinary clock dial or face.
The two discs are fitted one over the other upon the central pivot pin c and an
index finger d representing the hour hand of a timepiece is arranged between them
upon the pivot c so that the discs and the index finger can be turned to any
desired positions upon the said pivot. A cap e is screwed or otherwise fitted upon
the pivot e to secure them all together.
The compass disc a is divided so as to show the ordinary points of the compass
and may also be further divided into degrees. The clock disc b is divided into the
usual twelve hours and each hour is again divided in six, as shown, so that each
division represents ten minutes. The dial may also be further divided into minutes
if required.
In order to make an observation, the index finger d is moved to indicate the
correct time upon the disc b and the disc a is then turned until the S point is
exactly midway between the actual time as shown by the index finger d and the
numeral 12 on the dial. In Fig. 2 the apparatus is shown in position for taking
an observation, the time being 2-30 this time being indicated upon the dial 6 by
the index finger d. The disc is then rotated until the S point is halfway between
the finger d and the numeral 12 i.e. at 1.15 and the index finger à directed
towards the sun. The compass disc a will lie with its N point directed to the true
north and the other points of the compass will be in their proper positions.
The discs may conveniently be made of cardboard or of thin metal plate or of
any other suitable substance. In the case of metal the clock dial divisions and
numera's and the compass marking and lettering and ornamental coloring of the
plates may be printed on paper and then attached to the discs by adhesive
substance.
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) An improved apparatus for determining the direction of true north and the
various points of the compass when the time of day is known, comprising two
discs marked one with the points of the compass and the other with the divisions
of a clock face, arranged upon a central pivot and an index finger adapted to be

page_text: turned to indicate the correct time upon
the clock disc and then
pointed towards the sun, the compass disc being then turned with its
S point midway between the index finger and the numeral 12 so that the compass
disc will indicate the points of the compass substantially as described.
(2) An improved apparatus for determining the direction of true north and the
various points of the compass when the time of day is known comprising the
compass disc a, and index finger d arranged upon the pivot e the apparatus being
used substantially as described with reference to the accompanying drawings.
Dated this 12th day of February 1898.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.