IMPROVEMENTS IN THE MARINERS' COMPASS
Year: 1858

page_text: LETTERS PATENT to David Irons, of 6, Cornwall Terrace, Creck Road,
Deptford, in the County of Kent, for the Invention of "IMPROVEMENTS IN
THE MARINERS' COMPASS."
Sealed the 5th November 1858, and dated the 8th June 1858.
PROVISIONAL SPECIFICATION left by the said David Irons at the
Office of the Commissioners of Patents, with his Petition, on the
8th June 1858.
I, DAVID IRONS, of 6, Cornwall Terrace, Creek Road, Deptford, in the
County of Kent, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN THE MARINERS' COMPASS," to be as follows:-
This Invention has for its object improvements in the mariners' compass,
and the peculiarity of this Invention consists in the so constructing a compass
that its needle shall at all times point due north and south. For this purposo
the card of a compass is constructed with three magnets or needles; one
needle is of the ordinary kind, and fixed on the card to point north and south,
the other two magnets are fixed to the card at right angles to the first needle
or magnet. The north end or pole of one of the two additional magnets is
outwards, and placed to the west of the north end or pole of the first-
mentioned magnet or needle. The third magnet has its south pole outwards,
and in position it corresponds with the east point on the card.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Irons in the Great Seal Patent Office on the
8th December 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
IRONS, of 6, Cornwall Terrace, Creck Road, Deptford, in the County of Kent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of June, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said David Irons, Her special licence that I, the said David Irons, my
executors, administrators, and assigns, or such others as I, the said David
Irons, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MARINERS' COMPASS," upon the condition (amongst others) that I, the said David
Irons, my executors or administrators, by an instrument in writing under my, or
their, or one of their bands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, tho said David Irons, do hereby declare
the nature of the said Invention, and in what manner the samo is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
This Invention has for its object improvements in the mariner's compass,
and the peculiarity of this Invention consists in the so constructing a compass,
that its needle shall at all times point due north and south. For this purpose
the card of a compass is constructed with three magnets or needles; one
needle is of the ordinary kind, and fixed on the card to point north and south,
the other two magnets are fixed to the card at right angles to the other needle
or magnet. The north end or pole of one of the two additional magnets is
outwards, and placed to the west of the north end or pole of the first-

page_text: Having thus stated the nature of my said Invention, I will proceed to
describe the manner of performing the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shews a plan of a compass card, the several magnets applied
thereto being shewn in blue and red lines; Figure 2 shews the arrangement
of magnets when the compass card is to be used in ships constructed of wood;.
Figure 3 is the arrangement of magnets applied when the compass is intended
to be used on board of a ship or vessel constructed of iron or a wooden ship
sailing in high latitudes north or south; Figure 4 shows another arrangement
of magnets suitable to be used on board a ship or vessel constructed of wood
or of iron. a, a, is the main or ordinary magnet, with its poles pointing north
and south; is another magnet, having its south pole outwards, and pointing
to the east; c is another magnet, with its north pole outwards, and pointing
west, and such two additional magnets b, c, are fixed on the compass card on
the line pointing cast and west, as shewn at Figure 2. When a compass card
constructed according to my Invention is intended for use on board a ship or
vessel constructed of iron, then it is preferred to apply, in addition to the
combination of magnets a, b, c, four supplemental magnets, as is shewn in
Figure 3, and such compass card may also be applied when the compass is for
use on board a ship or vessel constructed of wood. Thus c' and ' are two
short magnets, which, like the magnet c, have their north poles outwards;
they are fixed to the compass card on the two radii, indicating respectively the
points north-west and north-east. The additional magnets and b², like that
at b, have their south poles outward; they are fixed to the compass card on the
radii, indicating respectively the south-west and south-east points of the
compass.
In Figure 4, another method of arranging magnets for a compass card
according to my Invention is shown. There is the same application of the
combination of magnets a, b, and c, as shewn in Figures 1, 2, & 3, together
with the supplemental bent magnets d, d', d³, d³, of which, by preference,
four are used. The directions of the several poles of these additional magnets
are shewn in the Drawing. In some cases I apply bent magnets in addition
to my combination of magnets a, b, c, around or near the outer edge of the
card, as shewn at Figure 5, where an arrangement of compass card, such as is
shewn at Figure 3, is represented, but with the addition of four bent magnets

page_text: e, e¹, e, e³, at or towards the edge of the card, and having their magnetic poles
pointing as shewn in the Drawing. It is preferred to mount the compass card
in a bowl of cast iron, and to line the box, case, or binnacle containing it with
wrought iron.
Figures 6 and 7 show respectively a vertical section and a horizontal section
of the bowl and case constructed and arranged in the manner preferred, the
iron bowl being marked f, and the lining of the case g.
In witness whereof, I, the said David Irons, have hereunto set my
hand and seal, this Seventh day of December, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
S. CARPMAEL.
DAVID IRONS. (L.S.)