IMPROVE- MENTS IN MARINERS' AND OTHER COMPASSES
Year: 1866

page_text: LETTERS PATENT to John Sacheverell Gisborne, of Liverpool, in the
County of Lancaster, Electrical Engineer, for the Invention of "IMPROVE-
MENTS IN MARINERS' AND OTHER COMPASSES."
Sealed the 30th April 1867, and dated the 3rd November 1866.
PROVISIONAL SPECIFICATION left by the said John Sacheverell Gisborne
at the Office of the Commissioners of Patents, with his Petition, on
the 3rd November 1866.
I, JOHN SACHEVERELL GISBORNE, of Liverpool, in the County of Lancaster,
Electrical Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MARINERS' AND OTHER COMPASSES," to be as follows:-
The object of my Invention is to protect the magnetic needle or needles in
mariners' and other compasses from local attraction or influences, however
caused or induced, and thereby to leave the needle or needles to point "true
polarity" at all times.
This I effect, first, by electricity and apparatus of the following construc-
tion:-On or between pivots in the ordinary manner I support or balance the
needle or needles and card; these I surround by a speroidal vessel open at
top and bottom, as if two opposite parts of the vessel had been cut off, made
of one or more pieces of metal. The said vessel is as a whole or in parts or
segments covered with insulated copper or other wire laid on in opposite
directions, and a current of electricity from a battery is passed therethrough.

page_text: The spheroidal vessel when in one connected piece and the insulated wire,
when a current of electricity is passing through, act as or become an electro-
magnet, and when the vessel is built up in pieces there are several electro-
magnets, the object being to leave the magnetic needle or needles under equal
influences at all times. When the magnetic needle dips, its ends are equi-
distant from the edges of the openings in the spheroidal vessel, and are
therefore attracted and repelled by equal forces. The electro-magnet or
electro-magnets neutralize any local attraction or influence, and leave the
needle or needles and card free to traverse freely. It will. be obvious the shape
of the vessel may be varied.
And, secondly, by so-called mechanical means I encircle or surround the
needle or needles aud card by a speroidal, cylindrical,, or other suitably
shaped metallic vessel open at the top and sometimes also at the bottom. The
thickness of the metal is made such that local attraction will be counteracted.
To prevent the vessel from acquiring natural polarity I give to it by clockwork,
falling weights, or by other means a rotary motion round a vertical axis. In
this construction, as in the electric first above mentioned, it will be obvious
the protecting metallic vessel may either be swung on gimballs or made
stationary.
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 3rd May 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SACHEVERELL GISBORNE, of Liverpool, in the County of Lancaster, Electrical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of November, in the year of our Lord
One thousand eight hundred and sixty-six, 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
Sacheverell 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

page_text: "IMPROVEMENTS IN MARINERS' AND OTHER COMPASSES," 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 be.
performed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the Sheet of illustrative Drawings
bereunto attached, and to the figures and letters thereon, that is to say:-
The object of my Invention is to protect the magnetic needle or needles in
mariners' and other compasses from local attraction or influences, however
caused or induced, and thereby to leave the needle or needles to point "true
polarity" at all times.
This I effect, first, by electricity and apparatus of the following construc-
tion: On or, between pivots in the ordinary manner I support or balance the
needle or needles and card; these I surround by a spheroidal or other suitably.
shaped vessel open at top and bottom, made of one or more pieces of metal.
The said vessel is as a whole or in parts or segments covered with insulated
copper or other wire, and a current of electricity from a battery is passed
therethrough. By this part of my Invention I place the magnetic needle or
needles under equal influences at all times; when the needle or needles dips
or dip, its or their ends are equidistant respectively from the upper and lower
edges of the openings in the said vessel.
And, secondly, by so-called mechanical means, I encircle or surround the
needle or needles and card by a cylindrical or other suitably shaped metallic
vessel open at the top and sometimes also at the bottom. The thickness of
the metal is made such that local attraction will be counteracted. To prevent
the vessel from acquiring natural polarity I give to it by clockwork, falling
weights, or by other means a rotary motion round a vertical axis.
Compasses constructed or arranged according to the first part of my
Invention are represented on the accompanying Sheet of Drawings by Figures
1 to 10 inclusive.
Figure 1 is a vertical transverse section, and Figure 2 a side elevation of
a spheroidal vessel open at top and bottom covered with insulated wire.
a is the vessel preferably made of iron of uniform thickness in two halves

page_text: screwed together; b is the insulated wire, the ends 6¹ of which are connected
to a dry or other electric battery; 6 prevents a from acquiring natural
polarity; a and b and the needles and card marked c are swung in gimballs.
Figure 3 is a vertical transverse section, and Figure 4. a side elevation.
of an arrangement with double protectors of metal d made in two pieces and
screwed together, each covered with insulated wire e. f are pieces of india-
rubber or other material, under and over which the wires e are made to pass,
and are thereby prevented from slipping. A circular plate 9 connects the two
protectors d. The needles and card h are supported by the stem i secured.to
and rising from the deck.
Figure 5 is a vertical transverse section, and Figure 6. a side elevation of
an arrangement in which the protecting apparatus or vessel is built up of
staves A; consisting of solid metal pieces j, around each of which insulated
wire is wrapped. is continued: from: one stave to another, and the
ends are led to a battery. The staves A are stationary in this modifi-
cation, and; are secured by the ring 7 from which the needles and card.m are
swung.
Figure 7 is a vertical transverse section, and Figure 8.a side elevation
(part of the cover being removed) of cylindrical apparatus. n is the metal
cylinder with flanges, within which the bands B consisting of hoops o and
insulated wire p are placed; these bands B. so laid on that joint are broken
both horizontally and vertically. The ends of p, marked p¹, are connected to
a battery. is a cover with centres for gimballing in the ordinary manner,
the needles and card r being supported by a spindle s on a cross bar t.
Figure 9 is a vertical transverse section, and Figure 10 a side elevation of
an arrangement similar to Figures 7 and 8. The wire u is laid on the
cylinder direct, and no cover is provided.
Compasses constructed or arranged according to the second part of my
Invention are represented on the Drawings by Figures 11 to 14 inclusive.
Figure 11 is a vertical transverse section, and Figure 12 a plan view of an
arrangement in which the protecting vessel vis spheroidal and open at top
and bottom. On the periphery of v teeth are formed; these gear with a pinion w
operated by any suitable mechanism, either to move continuously in one
direction, or with an intermittent or to-and-fro motion. The needles and card a
are supported on a stem a¹ secured to the ship; vis supported on a ring or on
antifriction rollers y.
Figure 18 is a vertical transverse section, and Figure 14 a plan view of an
arrangement, in which a cylindrical vessel z closed at bottom is driven by teeth a³
and pinion ; is always driven at a very slow speed, both when the motion

page_text: is continuous and intermittent, so that the needles and card will have sufficient
time for traversing.
Having now described the nature of my said Invention, and particularized
the same by various modifications, I would have it understood that what I
claim is,
First, the employment of spheroidal or other suitably shaped vessels made
of metal in one, two, or more pieces for protecting the magnetic needle
or needles in mariners' and other compasses when the said vessels are
covered or protected by or with insulated wire, substantially as herein described
and shewn on the accompanying Sheet of Drawings.
And, second, protecting the magnetic needle or needles in mariners' and
other compasses by surrounding or encircling them by or with a metallic
vessel of spheroidal or other shape, when the said metallic vessel has a rotary,
intermittent, or to-and-fro motion given thereto, at such speed as shall
prevent it acquiring polarity, substantially as herein described.
In witness whereof, I, the said John Sacheverell Gisborne, have here-
unto set my hand and seal, this First day of May, in the year of our
Lord One thousand eight hundred and sixty-seven.
JOHN SACHEVERELL GISBORNE.
(L.B.)
In the presence of
JOHN T. KING,
Patent Agent,
Liverpool.