IMPROVEMENTS IN SHIPS' COMPASSES
Year: 1867

page_text: LETTERS PATENT to The Right Honorable James, Earl of Caithness,
of Hill Street, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN SHIPS' COMPASSES."
Sealed the 26th November 1867, and dated the 31st May 1867.
PROVISIONAL SPECIFICATION left by the said Right Honorable James,
Earl of Caithness at the Office of the Commissioners of Patents, with.
his Petition, on the 31st May 1867.
1, The Right Honorable JAMES, Earl of CAITHNESS, of Hill Street, in the
County of Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SHIPS' COMPASSES," to be as follows:-
This Invention relates to a mode of suspending ships' compasses with a
view to prevent undue oscillation in heavy seas, and consists essentially in
attaching to the compass box or case containing the card or needle a weighted.
rod or pendulum, which is allowed to swing freely in a ball-and-socket joint
situate as close as possible to the compass. The socket for the ball joint is
contained in the upper part of a "binicle," or other convenient frame or
support which will allow of the free play or swing of the pendulum. The

page_text: bob or weight of the pendulum is made adjustable along the rod by a set
screw or other convenient contrivance so as to admit of alteration or
adjustment. By this contrivance the compass is constantly maintained in a
horizontal position as whatever may be the motion of the ship the pendulum
will always remain perpendicular.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Right Honourable James, Earl of Caithness, in the Great
Seal Patent Office on the 27th November 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, The Right
Honourable JAMES, Earl of CAITHNESS, of Hill Street, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of May, 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 Right Honourable James, Earl of Caithness, Her special license that I,
the said Right Honourable James, Earl of Caithness, my executors,
administrators, and assigns, or such others as I, the said Right Honourable
James, Earl of Caithness, my executors, administrators, or 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 SHIPS' COMPASSES," upon the condition (amongst others)
that I, the said Right Honourable James, Earl of Caithness, my executors or
administrators, by an instrument in writing, under my band and seal, 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 Right Honourable James, Earl of
Caithness, 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, reference being had to the
accompanying Sheet of Drawings and to the letters and figures marked
thereor, that is to say:―

page_text: My said Invention relates to a mode of suspending ships' compasses with a
view to prevent undue oscilation in heavy seas, and consists essentially in
attaching to the compass box or case containing the card or needle a
weighted rod or pendulum which is allowed to swing freely by a ball-and-
socket joint situate as close as possible to the compass. The socket for the
ball is contained in the upper part of a "binnacle," or other convenient frame
or support which will allow of the free play or swing of the pendulum. The
bob or weight of the pendulum is made adjustable along the rod by a set
screw or other convenient contrivance, so as to admit of alteration or
adjustment. By this contrivance the compass is constantly maintained in a
horizontal position as whatever may be the motion of the ship the pendulum
will always remain perpendicular.
The accompanying Drawing represents a vertical section of a marriner's
compass mounted according to my Invention.
A is the "binnacle" or case, the sides of which should incline outwards
towards the lower portion, or be otherwise constituted or shaped so as to afford
free swing inside the "binnacle" for the weighted pendulum B in roughest
weather. On the upper end of the rod of the pendulum there is fitted or
formed a ball C, which turns freely in any direction in a socket or holder of
brass or other suitable material D, carried by and secured to the top of the
"binnacle" or support in any convenient or suitable manner.
To the upper
side of the ball C I secure by the aid of a screw a the compass box E
containing the ordinary pivotted card or needle F protected by a glass
in the usual manner; the whole should be enclosed or protected by an outer
casing of any convenient form protected with a glass and with suitable
"binnacle" lamps. The pendulum may be made of any length, but I have
found that a length of about two feet six inches from the centre of oscilation
to the centre of the weight or pendulum bob G to answer well in practice;
and I prefer to make such weight adjustable along the pendulum rod, and to
secure it at any desired height by means of a pinching screw 6 or by any other
convenient contrivance. In order to prevent the accidental rotation or
circular displacement of the compass box I propose to insert a pin c through
the side of the socket or holder D, and into a groove or channel made in the
side of the ball C.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured to me by
the berein-before in part recited Letters Patent is, the mounting of a

page_text: marriner's compass upon the upper end of a weighted pendulum or rod, which
is so suspended as to be free to oscilate or gyrate in any direction, substantially
as and for the purpose herein-before described.
In witness whereof, I, the said James, Earl of Caithness, have to this
my Specification set my hand and seal, this Sixteenth day of
November, One thousand eight. hundred and sixty-seven.
CAITHNESS. (L.S.)