IMPROVE- MENTS IN BINNACLES OR APPARATUS FOR HOLDING MARINE COMPASSES
Year: 1858

page_text: LETTERS PATENT to James Edgar Cook, of Greenock, in the County of
Renfrew, North Britain, Booking Clerk, for the Invention of "IMPROVE-
MENTS IN BINNACLES OR APPARATUS FOR HOLDING MARINE COMPASSES."
PROVISIONAL SPECIFICATION left by the said James Edgar Cook at the
Office of the Commissioners of Patents, with his Petition, on the 19th
February 1858.
I, JAMES EDGAR Cook, of Greenock, in the County of Renfrew, North
Britain, Booking Clerk, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN BINNACLES OR APPARATUS FOR HOLDING MARINE COMPASSES,"
to be as follows, that is to say :-.
This Invention relates to the arrangement and construction of binnacles or
apparatus for holding marine compasses, for the purpose of doing away with
the deranging influence of local attraction, and at the same time preserving,
all the lively power and effect of the needle. The actual holding part of the
improved binnacle consists of a metal cylinder, within which is a second.
cylinder of cork, an annular space of considerable width being left between.
the two cases; the inner case has within it suitable apparatus for holding the
compass, which may be of any ordinary kind. The metal preferred for the
outer case is steel, or what is technically known as." homogeneous metal," or.

page_text: it may be of iron, and the space between the two cases may either be left
open, as is preferred, or it may be filled up with any suitable nonconducting
material. This arrangement has the effect of nullifying local attraction,
whilst it leaves the powers of the needle unimpaired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,. filed
by the said James Edgar Cook in the Great Seal Patent Office on the
19th August 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
EDGAR COOK, of Greenock, in the County of Renfrew, North Britain, Booking
Clerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of February, 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 James Edgar Cook, Her special license that I, the said James Edgar
Cook, my executors, administrators, and assigns, or such others as I, the
said James Edgar Cooke, 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 "IMPROVE-"
MENTS IN BINNACLES OR APPARATUS FOR HOLDING MARINE COMPASSES," upon the
condition (amongst others) that I, the said James Edgar Cook, by an instru-
ment in writing under my hand, 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.
I
. NOW KNOW YE, that I, the said James Edgar Cook, 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 Drawings, and to the
letters and figures marked thereon, that is to say :-
My said Invention relates to the arrangement and construction of binnacles
or apparatus for holding marine compasses, for the purpose of doing away
with the deranging influence of local attraction, and at the same time> pre-

page_text: .
serving all the lively power and effect of the needle. The actual holding. part
of the improved binnacle consists of a metal cylinder, within which is a second
cylinder of cork, an annular space of considerable width being left between
the two cases; the inner case has within it suitable apparatus for holding the
compass, which may be of any ordinary kind. The metal preferred for the
outer case is steel, or what is technically known as "homogeneous metal,"
or it may be of iron, and the space between the two cases may either be left
open, as is preferred, or it may be filled up with any suitablé non-conducting
material. This arrangement has the effect of nullifying local attraction, whilst
it leaves the powers of the needle unimpaired.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several Figures on the explanatory Sheet of
Drawings which I have hereunto appended, for the purpose of showing certain
modifications under which my improvements may be judiciously carried out in
practice.
Figure 1 on my Drawing is an elevation partially in section of one arrange-
ment of my improved binnacle or case for holding a marine compass; Figure 2
sa plan corresponding to Figure 1. According to this modification the
binnacle A is a cylinder of iron or steel closed at its lower part, thus forming
a basin-like holder, in the centre of which the compass is suspended. The
binnacle or compass holder A may be made of iron or steel, in either case the
metal may be cast or wrought so as to be of uniform thickness throughout;
or the binnacle may be cast or forged roughly, and afterwards. turned in a
lathe to give it a smooth face and equalise the thickness of metal. If preferred,
.however, the binnacle or outer. holder may be made of that kind of metal
technically known as "homogeneous metal," which is peculiar for its uniform
structure throughout. The binnacle or outer holder A is supported by means
of the gimbal B, which turns freely in the outer suspending ring C, so that
the binnacle and the compass contained therein are free to turn upon the
supporting points. Concentric with the interior of the binnacle A, is arranged
a cylinder of cork E, or of cork combined with other suitable non-conducting
material or materials. This cylinder or non-conducting medium. E may be
made up of pieces of cork joined together with shellac or other adhesive mate-
rial, or it may be formed of layers of cork and silk, or other textile material
cemented together by means of a solution of shellac. In the accompanying
Drawing are shown two ways of arranging the cork cylinder so as to connect
it with the binnacle .A. According to one mode, the cork cylinder E is
secured to a circular base F, which is formed of wood or other non-conducting
material; this base is fastened to the bottom of the binnacle A, so that the

page_text: cylinder E is exactly concentric with the binnacle. The cylinder of cork has
fitted to it an external ring of brass G, which serves to strengthen the upper
part; concentric with the ring G is an inner ring H, in which the supporting.
arms of the gimbal I are centred. The inner gimbal J, and the compass Ķ
are arranged within the gimbal I in the ordinary manner; this part of the
arrangement does not differ from the compasses in ordinary use. The other
mode of arranging the cork cylinder E consists in suspending it freely within
the binnacle A, by means of a gimbal fitted to the exterior of the cylinder in
place of the ring G. The projecting arms of the cylinder gimbal are indicated
by the red lines L, in Figure 2 of my Drawing; the free extremities of the
arms are carried in a ring M, which is fitted tightly within the binnacle A. One
mode of arranging or fitting up the binnacle A consists in making the outer
ring of metal C with projecting arms, forming a gimbal as shown in Figure 2
of the accompanying Drawing. The arms of the gimbal may be carried
in a pair of columnar or other standards springing from or affixed to a
suitable base; this stand may be made with four of these columns, the other
two being connected by an arched or curved bar of metal for the purpose of
supporting one or more lamps to illuminate the compass card at night. It is
obvious, however, that the external fitting or arrangement of the metallic
binnacle may be greatly varied, so as to adapt it to the particular purpose or
position in which the compass is to be placed. The effect of surrounding the
compass with a metallic binnacle or case and an internal non-conducting
material is to counteract any external or local attraction, that would otherwise
interfere with the efficient performance of the instrument.
In this manner of
arranging marine compasses, the power of the magnetic needle continues
unimpaired, irrespective of its position or contiguity to metals or other
substances external to the binnacle that would otherwise disturb its action.
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 may observe in conclusion that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my Invention; but what I
consider to be novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,―
First, the general arrangement and construction of binnacles or apparatus
for holding marine compasses as herein-before described.
Second, the system or mode of constructing the binnacles or holders of
marine compasses, in which the magnetic instrument is supported or held

page_text: within a cylinder or surrounding medium of cork or other suitable non-con-
ducting material as herein-before described.
Third, the system or mode of constructing the binnacles or apparatus for
holding marine compasses of steel or iron, with a view to counteract local
disturbing causes, a cylinder of cork or other non-conducting material being
interposed between the magnetic needle and the metallic binnacle as herein-
before described.
Fourth, the system or mode of arranging and constructing the binnacles or
holding apparatus of marine compasses, wherein the magnetic needle is
suspended on gimbals carried by or in the interior of a cork or other non-
conducting chamber, which chamber again is carried by or in a steel or iron
chamber or cylinder, also suspended on gimbals.
In witness whereof, I, the said James Edgar Cook, have hereunto set
my hand and seal, this Sixteenth day of August, One thousand eight
hundred and fifty-eight.
J. E. COOK. (L.S.)