IMPROVEMENTS IN THE MARINER'S COMPASS
Year: 1854

page_text: LETTERS PATENT to John Gray, of 25 and 26, Strand Street, Liverpool,
for the Invention of "IMPROVEMENTS IN THE MARINER'S COMPASS,"
PROVISIONAL SPECIFICATION left by the said John Gray at the Office of
the Commissioners of Patents, with his Petition, on the 28th August
1854.
I, JOHN GRAY, of 25 and 26, Strand Street, Liverpool, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN THE MARINER'S COMPASS " to
be as follows:-
This Invention consists in so arranging and constructing ships' compasses as
to counteract the vibratory action to which they are subject in steam ships and
other vessels. The compass is suspended within a vessel or bowl, which is
held in a state of suspension within another vessel or bowl containing fluid,
which I prefer to be of thick varnish, on account of its adhesive and sluggish
action, which is beneficial in keeping the inner bowl steady; and I connect the
bottom of the inner vessel or bowl with the bottom of the outer vessel or bowl
by springs; and I also connect the upper and inner rim with the outer rim by
vulcanized india-rubber or other springs, the inner vessel or bowl being kept
ונם .

page_text: in a central position by tangential screws, so as to counteract the lateral action,
whilst the springs below will regulate the vertical position of the inner bowl in
conjunction with the fluid contained in tho outer bowl.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Gray in the Great Seal Patent Office on the
27th February 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GRAY, of 25 and 26, Strand Street, Liverpool, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of August, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, 1er heirs and successors, give and grant unto me,
the said John Gray, Her special licence that I, the said John Gray, iny
executors, administrators, and assigns, or such others as I, the said John
Gray, 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 MARINER'S
COMPASS," upon the condition (amongst others) that I, the said John Gray,
by an instrument in writing under my hand and scal, 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 Gray, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and bythe following statement
thereof (that is to say) :-
This Invention consists in so arranging and constructing ship's compasses as
to counteract the vibratoryaction towhich they are subject in steam ships and
other vessels. The compass is suspended within a vessel or bowl, which is held
in a state of suspension within another vessel or bowl containing fluid, which I
prefer to be of thick varnish, on account of its adhesive and sluggish action,

page_text: which is beneficialin keeping the inner boul stondy; and I connect the hortow
of the inner vessel or bowl with the bottom of the outer vessel or bowl by
springs; and I also connect the upper and inner rim with the outer rim by
vulcanized india-rubber or other springs, the inner vessel or bowl being kept
in a central position by tangential screws, so as to counteract the lateral action,
whilst the springs below will regulate the vertical position of the inner bowl
in conjunction with the fluid contained in the outer bowl.
Having thus stated the nature of my Invention, I will now proceed to
describe the manner in which I perform the same.
of the inner vessel or bowl with the bottom of the outer vessel or bowl by
springs; and I also connect the upper and inner rim with the outer rim by
vulcanized india-rubber or other springs, the inner vessel or bowl being kept
in a central position by tangential screws, so as to counteract the lateral action,
whilst the springs below will regulate the vertical position of the inner bowl
in conjunction with the fluid contained in the outer bowl.
Having thus stated the nature of my Invention, I will now proceed to
describe the manner in which I perform the same.
DESCRIPTION OF THE DRAWING.
Figure 1 is a section, and Figure 2 a plan, of a compass arranged accord-
ing to this Invention. A is the outer ring of the gimble, on which are bearings
for the axes B,fixed on the vessel C, which contains a fluid, such as a saturated
solution of common salt; or it may be varnish or other fluid which is rather
sluggish in its movements. In this vessel C floats the vessel D, in which the
needle and card are contained. E, E, are two pieces of metal attached to the
vessel D, which slide in guides F, attached to the vessel C. To the vessel D
are also attached four lugs G, which uip vulcanized india-rubber springs H,
to the ends of which are fastened netal screws, having square shanks, which
pass through holes of a similar form in the uprights Iattached to the vessel C.
The screws are furnished with nuts J, by means of which the tension of the
springs may be adjusted, and the vessel Dheld concentrically withthevessel C,
and this is assisted by the springs D'.
I will now describe the manner in which the needle and card are supported,
the object of the arrangement being still further to decrease vibration. Kis
a metal box, in which is contained a vulcanized india-rubber disc L, on which
the foot of the spindle M presses. The spindle slides freely through the top
of the box K, and also of the box N above it; within the box N is a spiral
spring, which acts on the disc O on the spindle M, and thus prevents it from
pressing too strongly on the india-rubber disc L.
On the top of the spindle M is another box P, in which also is a vulcanized
india-rubber disc Q, in the centre of which the cup R (which receives the pin
of the compass card) is fixed. Round the cup R is stretched a ring of
vulcanized india-rubber, to prevent it from jarring against the cover of the
box P. S is the compass card, on which, by preference, two needles T and U
are mounted on centres at V and W; X are plates of talc or other material,
which by offering a resistance to the air, check the oscillations of the compass;

page_text: Y is a glass which covers the vessel D; and Zis a pin, descending from the
glass Y, to prevent the card being thrown out ofits bearing by a sudden shock.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I make no claim to
the parts separately; but what I claim is, the combination of the vessels C
and D, and the use of a liquid and springs to counteract vibration, as herein
described.
In witness whereof, I, the said John Gray, have hereunto set my hand
and seal, this Twenty-fourth day of February, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
JOIN DIGNAN,
12, Hope Place, Liverpool,
Feb 24, 1855.
JOHN GRAY. (L.S.)