IM- PROVED MEANS AND APPARATUS POR PROTECTING THE NEEDLES OF MARINERS' AND OTHER COMPASSES FROM LOCAL ATTRACTION
Year: 1867

page_text: LETTERS PATENT to John Sacheverell Gisborne, of Liverpool, in the
County of Lancaster, Electrical Engineer, for the Invention of "IM-
PROVED MEANS AND APPARATUS POR PROTECTING THE NEEDLES OF MARINERS'
AND OTHER COMPASSES FROM LOCAL ATTRACTION."
Sealed the 6th September 1867, and dated the 9th March 1867.
PROVISIONAL SPECIFICATION left by the said John Sacheverell Gis-
borne at the Office of the Commissioners of Patents, with his Petition,
on the 9th March 1867.
1, JOHN SACHEVERELL GISBORNE, of Liverpool, in the County of Lancaster,
Electrical Engineer, do hereby declare the nature of the said Invention for
"IMPROVED MEANS AND APPARATUS FOR PROTECTING THE NEEDLES OF MARINERS'
AND OTHER COMPASSES FROM LOCAL ATTRACTION," to be as follows:-
The object of my Invention is to prevent those deviations or errors of
mariners' and other compasses which result from local attraction, whether the
attraction be of metal employed in the construction or outfit of the ship
itself, or of metal carried as cargo, or of metal in adjacent ships or con-
structions, or of natural local attraction as at St. Helena and other places.
For this purpose I employ (1) round or flattened insulated iron wire and
currents of electricity conjointly, and (2) round or flattened insulated iron
wire by itself. The insulated iron wire is in both of these devices wound or
built up into a cylindrical or other shape, and is placed so as to encircle or
surround horizontally the magnetic needle or needles, either by being swung

page_text: in gimballs with or as part of the compass box or made stationary. The
needle or needles is or are supported in any usual manner. When electricity
is employed with the iron wire wound or built into the shape mentioned the
insulated iron wire is the conductor, the ends of it being connected to the
poles of a battery, and as the object of using electricity with the iron wire is to
prevent the said iron wire from acquiring a natural polarity, and to intensify
the counteracting influence of such wire the electric currents may either be
continuous or intermittent.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Sacheverell Gisborne in the Great Seal Patent Office
on the 6th September 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SACHEVBRELL GISBORNE, of Liverpool, in the County of Lancaster, Electrical
Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of March, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Sacheverell Gisborne, Her special license that I, the said John Sache-
verell Gisborne, my executors, administrators, and assigns, or such others as
I, the said John Sacheverell Gisborne, 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 "IMPROVED MEANS AND APPARATUS FOR PROTECTING THE NEEDLES
OF MARINERS' AND OTHER COMPASSES FROM LOCAL ATTRACTION," upon the condition
(amongst others) that I, the said John Sacheverell Gisborne, my executors
or administrators, by an instrument in writing under my, or their, or one of
their hands 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, the said John Sacheverell Gisborne, do hereby
declare the nature of my said Invention, and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
The object of my Invention is to prevent those deviations or errors of
mariners' and other compasses which result from local attraction, whether the
attraction be of metal employed in the construction or outfit of the ship
itself, or of metal carried as cargo, or of metal in adjacient ships or con-
structions, or of natural local attraction as at St. Helena and other places.
For this purpose I employ (1) round or flattened insulated iron wire and
currents of electricity conjointly, and (2) round or flattened insulated iron
wire by itself. The insulated iron wire is in both of these devices wound or
built up into a cylindrical or other shape, and is placed so as to encircle or
surround horizontally the magnetic needle or needles, either by being swung
in gimballs with or as part of the compass box, or made stationary. The
needle or needles is or are supported in any usual manner.
When electricity
is employed with the iron wire wound or built into the shape mentioned the
insulated iron wire is the conductor, the ends of it being connected to the
poles of a battery, and as the object in view in using electricity with the iron
wire is to prevent it, the said iron wire, from acquiring a natural polarity
and to intensify the counteracting influence, the electric currents may either
be continuous or intermittent.
Some of the modes which I have found to answer well of applying the
said insulated iron wire are illustrated on the accompanying Sheet of Drawings
in such manner that others will readily obtain a knowledge of my Invention
and be enabled to carry the same into practical effect.
Fig. 1 is a side elevation, and Fig. 2 a transverse section of a cylindrical
-protector composed of insulated iron wire a, laid on horizontally or built up
into the cylindrical shape over the frame b; c is a cover or case provided
with gimball centres d; d, are required when the protector is fitted so as to
swing, but when the protector is stationary c and d are not required, it being
sufficient to leave a open as shewn on Fig. 1. Fig. 3 is a transverse section
of apparatus similar to Fig. 2, but provided with a bottom part. e is the
insulated iron wire; f, the frame; g, the case or cover with gimball centres h;
i, the insulated iron wire of the bottom part with pin or centre j to support
the card and needle. Fig. 4 is a side elevation, and Fig. 5 a transverse
section of a cylindrical protector in which the insulating wire k is laid on
vertically or nearly so over the frame or hoop 1; m is a cover or case with
gimball centres n; m and n are used when desired. Fig. 6 is a transverse
section of a cylindrical vessel with a tapering bottom. o, the protecting wire
P,
the frame or hoop on which the wire o forming the cylindrical párt is laid
;

page_text: on vertically; 7, the case or cover with gimball centres r; 8, the frame of
the bottom part where over the wire o is laid horizontally; t, pin supported by
cross bar u for carrying the card and needle. When electricity is used the
end or ends of the insulated wire or wires are connected (sufficient slack for
free movement being left when the protector is swung in gimballs) to a dry
or other galvanic battery in any well known manner, and when the insulated
wire is used by itself I find it advisable to give an intermittent or continuous
motion to it, in accordance with the Invention for which I obtained Letters
Patent on the 3rd November A.D. 1866, No. 2863, so as thereby to prevent
the acquirement by it of natural polarity. The needle or needles and card
are supported or carried within the protecting vessel or coil of insulatted iron
wire in any ordinary or convenient manner.
Having now described the nature of my said Invention, and shewn how
the same can be carried into practical operation, I would have it understood
that I do not confine myself to the size or shape of the iron wire, nor to
the material by which it is insulated, as silk, india rubber, and other fibres
and substances are suitable; nor to the form into which it is built up or used,
as although I prefer the modifications shewn on the Drawings, other forms,
for instance those described in the Specification of the Inventions for which
I obtained Letters Patent dated respectively the 14th February A.D. 1863,
No. 401, and the 3rd November A.D. 1866, No. 2868, are suitable and
may be used; what I claim is, the use or employment of (a) insulated iron
wire and currents of electricity conjointly, and (6) insulated iron wire
by itself both when fixed and caused to move, as means for counteracting
local attraction of the magnetic needle or needles in mariners' and other
compasses, and preventing deviation or error, substantially as herein de-
scribed.
In witness whereof, I, the said John Sacheverell Gisborne, have here-
unto set my hand and seal, this Thirtieth day of August, in the year of
Lord One thousand eight hundred and sixty-seven.
In the presence of
JOHN T. KING,
Patent Agent,
Liverpool.
JOHN SACHEVERELL GISBORNE. (L.S.)