IMPROVEMENTS IN NAUTICAL INSTRUMENTS AND OTHER INSTRUMENTS OR APPARATUS OF PRECISION FOR USE AT SEA
Year: 1866

page_text: LETTERS PATENT to Michael Henry, of 68, Fleet Street, in the City of
London, Patent Agent, for the Invention of "IMPROVEMENTS IN NAUTICAL
INSTRUMENTS AND OTHER INSTRUMENTS OR APPARATUS OF PRECISION FOR USE
AT SEA. A communication from abroid by Jacques Augustin Normand,
of Havre, in the French Empire, Ship Builder.
Sealed the 7th September 1866, and dated the 21st March 1866.
PROVISIONAL SPECIFICATION left by the said Michael Henry at the
Office of the Commissioners of Patents, with his Petition, on the
21st March 1866.
I, MICHAEL HENRY, of 68, Fleet Street, in the City of London, Patent
Agent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN NAUTICAL INSTRUMENTS AND OTHER INSTRUMENTS OR APPARATUS OP
PRECISION FOR USE AT SEA," communicated to me from from abroad by Jacques
Augustin Normand, of Havre, in the French Empire, Ship Builder, to be as
follows:-
This Invention relates to nautical instruments and instruments and apparatus
of precision used at sea or on board ship, and in which the working of the
instrument or apparatus depends on it, or at least some portion of it, being
retained in a determinate or reliable position notwithstanding the pitching
and rolling of the vessel, which of course ordinarily affects the equilibrium of
all articles on board.
Now the object of the present Invention is to construct apparatus in such
manner that it or a portion of it shall maintain a determined position not-
withstanding the pitching and rolling of the vessel.

page_text: The Invention consists in constructing an apparatus as follows:-A light
plate is poised, suspended, or pivoted within a hollow sphere or spherical globe
completely filled with liquid, such plate being placed at the central part of
the sphere so that its centre of oscillation shall correspond with the centre of
the sphere, and to this plate at its centre a pointer or pin pointing upward is
attached. The globe may either be fixed or it may be supported on trunnions,
universal joints, or other like contrivances. In this apparatus, thus con-
structed, the plate and pointer will not be materially affected by the rolling or
tossing of the vessel, and the apparatus may therefore be applied to various
purposes in constructing nautical instruments and instruments of precision
used at sea.
I proceed to give some examples :-
1. For clinometers the apparatus may be suspended under a cap marked
off with divisions.
2. For mariners' compasses the plate may be marked off to serve as a
compass card.
3. For dip needles the plate may form the graduated circle.
4. For instruments for firing guns with precision at sea a rod terminating
in an arc, and free to be raised and lowered, may be fitted over the pointer
and communicate with an electric battery. When the rod is raised tho
current passes through a coil which holds up a striker, and when the rod is
depressed to touch the pointer the current passes through the plate instead of
to the coil, which thereupon ceases to hold up the striker, which drops and
fires the gun; or the contact may produce an electric spark for the purpose;
or the rod may terminate in a fork with springy limbs, which when parted
by the pointer will break circuit.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Michael Henry in the Great Seal Patent Office on the
21st September 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
HENRY, of 68, Fleet Street, in the City of London, Patent Agent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Twenty-first day of March, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reigu, did, for Herself, Her heirs and successors, give and graut unto me, the

page_text: said Michael Henry, Her special licence, that I, the said Michael Henry, my
executors, administrators, and assigns, or such others as I, the said Michael
Henry, 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 NAUTICAL INSTRU-
MENTS AND OTHER INSTRUMENTS OR APPARATUS OF PRECISION FOR USE AT SEA,"
communicated to me from abroad by Jacques Augustin Normand, of Havre,
in the French Empire, Ship Builder, upon the condition (amongst others) that
I, the said Michael Henry, my executors or administrators, by an instru-
ment 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 perfonned, 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 Michael Henry, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, as communicated to me, reference being had to the accom-
panying Drawings, that is to say:→
This Invention relates to nautical instruments and instruments and
apparatus of precision used at sea or on board ship, and in which the working
of the instrument or apparatus depends on the retaining of it or at least some
portion of it in a determined or reliable position notwithstanding the pitching
and rolling of the vessel, which of course ordinarily affects the equilibrium of
all articles on board.
Now the object of the present Invention is to construct apparatus in such
manner that it or a portion of it shall maintain a determined and reliable
position notwithstanding the pitching and rolling of the vessel.
The Invention consists in constructing an apparatus as follows:--A light
plate is poised, suspended, or pivoted within a hollow sphere or spherical globe
completely filled with liquid, such plato being placed at the central part of
the sphere so as to oscillate about its geometrical centro. The globe may be
fixed or it may be supported on trunnions, universal joints, or other like con-
trivances. In this apparatus thus constructed the plate will not be materially
affected by the motion of the vessel, if the plate be constructed very light and
so as to experience great resistance, frictional or otherwise, from the liquid
filling the sphere when moving independently of it. The reason of this

page_text: phenomenon may be thus explained:-When the apparatus is on board of a
vessel any motion imparted to it can be divided or resolved into two motions,
one of translation and one of rotation. The first motion has no action on
the liquid mass, which is incompressible and fills the sphere entirely so that
its centre of gravity cannot be displaced; the second motion evidently
produces a friction on the liquid, and this said friction, were the rotation
always imparted in the same direction would generate a corresponding
rotation in the liquid mass, but this is not the case, the rotatory motion is
only alternative and does not sensibly affect the immobility or inertia of the
central portion of the liquid sphere; the pivotted, poised, or suspended
plate which is placed in the middle of the sphere must necessarily retain a
corresponding immobility or state of rest. The apparatus may be applied in
the construction of various nautical instruments and instruments or apparatus
of precision used at sea.
I proceed to give some examples :-
1. For clinometers or instruments for indicating or measuring the pitching
or rolling of vessels the apparatus may be suspended under a cap marked off
with divisions.
2. For mariners' compasses the plate may be marked off to serve as a
compass card.
3. For dip needles the plate may form the graduated circle.
4. For instruments for firing guns with precision at sea a rod terminating
in an arc and free to be raised and lowered may be fitted over the pointer and
communicate with an electric battery. When the rod is raised the current
passes through a coil which holds up a striker, and when the rod is depressed
to touch the pointer the current passes through the plate instead of to the
coil, which thereupon ceases to hold up the striker which drops and fires the
gun, or the contact may produce an electric spark for the purpose, or the rod
may terminate in a fork with springy limbs, which when parted by the pointer
will break circuit.
I now proceed more particularly to describe, with reference to the accom-
panying Drawings, the best means known to me for carrying the Invention
into effect. I first propose to describe the Invention as applied to the con-
struction of a clinometer or instrument for measuring the pitching and rolling
of a vessel at sea.
Figure 1 is a vertical section of this improved clinometer, Figure 2 a vertical
elevation, and Figure 3 a plan or horizontal view of the same.
A is a hollow sphere supported like an ordinary mariners' compass by a
gimbal ring G in a box H, this box is fixed to a convenient part of the vessel;

page_text: the sphere is made by preference of metal, except, however, at the parts a, b,
which are made of glass, so that the interior pointer herein-after referred to
may be seen. B is a spherical glass cap marked with graduations or divisions,
as shown in Figure 3 and fixed by pims m m a little over the sphere A to the
box H so as to follow every motion of the ship exactly; C is a very light plate of
thin aluminium of the shape of a portion of a sphere, whose centre coincides
with that of the sphere A, so that the resistance it experiences from the liquid
is frictional. This plate is pivoted or suspended at about from 1 to 5 of an
inch above its centre of gravity within the sphere A, so as to oscillate at or
about the geometrical centre thereof; the plate is supported or pivoted on a
pedestal or rod I fixed to and rising from the bottom of the sphere A; D is a
pointer fixed to the plate C, and having at its upper end an ivory disc E. The
pointer points upwards, and the centre of the disc E when the apparatus is in
repose is placed exactly on the vertical line passing through the centre of the
sphere A. The sphere A is completely filled with liquid; the liquid which I
particularly recommend for the purpose is a mixture of parts linseed oil and
part essence of petroleum, i.e., the first product of the distillation of
petroleum oil. The liquid is introduced through a hole at the upper part of
the sphere, in which is afterwards fitted a stopper J; F is a reservoir partly
filled with air so as to allow of the due expansion of the liquid, this expansion
takes place through the pipe K.
Observations with this instrument are made in the following manner :-
When an observer looks from above at the disc E the glass cap B acts as a
mirror, and according to a well-known property of spherical mirrors the visual
ray always passes through the centre of the sphere; now if the observer's eye
be so placed that its own image coincide with the disc E, which is as already
stated placed in the vertical line passing through the centre of the sphere A, it
will evidently be in a vertical line passing through the centre of the sphere A.
The intersection of the visual ray with the graduated glass cap B will give
the angles of rolling and pitching which the observer requires to ascertain.
The Invention is applied to the description of mariners' compass known as
á liquid compass by making the bowl spherical instead of cylindrical, and a
thin plate marked so as to form the compass card and carrying a horizontal
magnetic needle is placed within the bowl, the plate being pivoted or sus
pended therein in the same manner as the plate C, Figure 1; the bowl being
spherical its oscillations due to the vessel's motion will exert a less disturbing
effect on the liquid contained in it than if it were cylindrical. The form of
the bowl constitutes the chief difference between a liquid compass constructed
according to this Invention and a liquid compass of ordinary construction:
:

page_text: This improve mode of constructing compasses is especially advantageous
when applied to mast compasses.
The Invention is applied to the construction of dip needles as follows:-
A light circular plate assuming the form of a slightly undulated plane is
placed vertically in a sphere filled with liquid like the sphere A, Figure 1,
the plate is pivoted therein just as the plato C, Figure 1, tho centre of oscil-
lation of this plate coinciding with the centre of the sphere. This plate is
graduated like the ordinary graduated circle of a dip needle, and it carries the
magnetic needle, which moves independently of the graduated plate, but in
the same plane and about the same centre. The plate and the needle should
both be made very light, and so as to experience great resistance when moving
through the liquid.
I next proceed to describe the Invention as applied to apparatus for firing
ship guns with precision at sea; Figuro 4 is a vertical section of this appa-
ratus; Figure 6 is a horizontal view of the same.
A is a hollow sphere fixed to a part of the ship and filled with liquid like the
sphero A, Figure 1. This sphere has within it a plato C pivoted or sup-
ported therein like the plate C shewn in Figure 1; D is a pointer attached
to the plate so that the upper end of it is in a vertical line passing through
the centre of the sphere A, when the whole apparatus is in repose. Part of
the pointer is formed of a spiral spring, which being very small is not shown
in the Drawing; G, G, are two rods, each terminating in (or having fixed
to it at bottom) an arc or segment 9, these rods aro fitted above the sus-
pended plate in a frame H, in such manner that they may be readily raised
and lowered by hand, and they may also be turned in a horizontal plane by
turning their frame H which works on the collar or ring w fastened to the
sphere A; y, y, are studs or finger-pieces fixed to the rods for conveniently
raising and lowering them. The rods, which are held up when at rest
by india-rubber tubes n, n, or springs, may be lowered sufficienty for them,
or rather for their arcs 9, 9, to come in contact with the top of the
pointer D when the axis X, X, of the whole apparatus is vertical.
For each of these rods the contact must take place only on one side of the
rod, that side being the one nearer to the axis of the suspended plate. The
plate C communicates with one electrode or pole of an electric or galvanic
battery, and the rods A, A, communicate with the other electrode or pole of
such battery. These electrodes are also united by an electro-magnetic coil J,
that is to say, the wires are coiled at J round a bar of soft iron, forming thus
an electro-magnet. The electro-magnet is supported on a bracket at a little
distance above the gun to be fired so as to hold up an iron
striker for firing

page_text: the gun; this striker acts on the explosive compound and discharges the gun
in the way strikers usually operate thereon for that purpose. When the current
passes through the coil the soft iron of course becomes magnetized and attracts
the striker and thereby holds it up clear of the gun, but when the current
does not pass through the coil the magnet releases the striker, which falls
and fires the gun, and this occurs when the pointer D comes in contact with
the arc at the end of one of the rods G, as then the electric current instead of
passing through the coil J takes the shorter way and passes through the rod I,
the plate C, and rod G, as the box upon which. the suspended plate is pivoted is
made of iridium or other hard metal. Now suppose the axis of the gun to be in
a vertical plane passing through the mark or point aimed at, so that the accuracy,
of the aim can only be affected or interfered with by the rolling and pitching
of the vessel, the frame H bearing the rods is turned horizontally so that the
arcs 9 shall be set transversely to the axis of the gun; then the proper.rod,.
that is to say, the rod which when lowered shall be struck on the proper side,
is lowered, and when during the rolling and pitching of the vessel the axis of
the apparatus is vertical the arc g will come in contact with the pointer, the
electric current will pass through the rod 1, plate C, pointer D, and rod G
and the striker will be released from the electro-magnet and will fall and
discharge the gun. A great part of the length of the pointer is made of
spiral spring, so that it may yield sufficiently to prevent the pointer from
being broken by the shock or concussion when the arcs 9 come in contact
with it, this spring arrangement allowing it to bend in any direction. The
ares 9 are used so that contact between them and the pointer may be
always attainable whatever may be the ship's inclination in a plane perpen-
dicular to the gun's axis.
Sometimes this arrangement may be modified, as shewn in Figure 7; hero
the rod which is single terminates in a fork having springy limbs; one end of
the coil communicates with one electrode or pole of the electric battery, and
the other end with the other pole through the fork when the two parts which
compose it are in contact at a. When struck by the pointer the springy
part of this fork is bent, as shown by the dotted line, the contact is destroyed,
the current interrupted, and the striker falls. Or the apparatus may be so
disposed that the firing of the gun may be produced by the induction electric
spark. In that case the arrangements are exactly the same as those shown in
Figures 4, 5, and 6, except (and this is the only difference) that the striker
and the coil are dispensed with and replaced by an induction coil machine.
The above described arrangements may be applied to the firing of several
guns together or simultaneously.

page_text: The exemplifications of this Invention above given in describing in what
manner it may be applied to clinometers, liquid compasses, dip needles, and
apparatus for firing guns with precision at sea suffice fully to explain the
mode in which the Invention can be applied to the construction of other
instruments of precision used at sen, in which such instrument or a portion
of it has to be retained in a determined or reliable or fixed direction not-
withstanding the rolling and pitching of the vessel.
Also, although I have particularly described certain particular arrange-
ments for applying the Invention or carrying it into effect in the construction
of certain instruments, I wish it to be understood that I do not restrict
myself to these particular mechanical details, as the same may be varied
without departing from the nature of the Invention as herein set forth.
Having now described the nature of the said Invention, and in what
manner the same may be performed, I declare that I claim in respect of
nautical instruments and other instruments and apparatus for use at sea,-
First, the employment of a hollow sphere filled with liquid and containing
a light plate pivoted, poised, or suspended at the geometrical centre of the
sphere so as to oscillate about this centre, substantially in the manner and
for the purpose described.
Second, the general arrangements and combinations of parts herein-before
described for the application of this principle of construction to clinometers,
mariners' compasses, dip needles, and apparatus for firing guns with precision
at sea.
In witness whereof, I, the said Michael Henry, have hereunto set my
hand and seal, this Twenty-first day of September, One thousand eight
hundred and sixty-six.
Witness
E. DE PASS,
68, Fleet Street,
London.
M. HENRY. (L.S.)