IMPROVEMENTS IN CONSTRUCTING SHIPS' COMPASSES AND THEIR BINNACLES, AND IN PREVENTING THE DEVIATIONS OF COMPASSES IN IRON OR STREL SHIPS."
Year: 1868

page_text: LETTERS PATENT to Frederick Arthur Paget, of 1, Seymour Chambers,
York Buildings, Adelphi, in the County of Middlesex, Civil and
Mechanical Engineer, for the Invention of "IMPROVEMENTS IN
CONSTRUCTING SHIPS' COMPASSES AND THEIR BINNACLES, AND IN PREVENTING
THE DEVIATIONS OF COMPASSES IN IRON OR STREL SHIPS."
PROVISIONAL SPECIFICATION left by the said Frederick Arthur
Paget at the Office of the Commissioners of Patents, with his
Petition, on the 12th March 1868.
I, FREDERICK ARTHUR PAGET, of 1, Seymour Chambers, York
Buildings, Adelphi, in the County of Middlesex, Civil and Mechanical
Engineer, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN CONSTRUCTING SHIPS' COMPASSES AND THEIR BINNACLES, AND IN
PREVENTING THE DEVIATIONS OF COMPASSES IN IRON OR STEEL SHIPS," to be as
follows:-
These improvements relate, firstly, to a novel mode of constructing
steering or binnacle, standard or surveying, and mast head compasses,
whether for sailing or steam ships, as also compasses for life and

page_text: other boats. From the small ratio of the mass and the momentum of
inertia of my compass card to its magnetic momentum, and also from
its low centre of gravity, it is delicate enough to be used in the finest
weather, while at the same time an identically similar card can be
employed in a storm, or at the mast head, or in a boat. The shortness of
its needles also brings it into favourable conditions in iron vessels as
regards deviation.
These improvements are applicable to all kinds and constructions of
compasses, whether to those mounted on a pivot with a common suspen-
sion cap, or to those termed "tubular" compasses in which the cap
and card are fixed to a tube loosely encasing the stern of the pivot, or
to those in which an axis is used somewhat similar to that of the
balance wheel of a chronometer, or to those in which the needles are
immersed in a liquid, such as water or spirits of wine, and buoyed
up by a float, and to other constructions. Instead of using several
needles arranged parallel to each other in one horizontal plane, I employ
two or more.short needles disposed one above another in a vertical plane
or, planes.
In adapting this part of my Invention to, for instance, such cards
as the well-known Admiralty observing and storm cards, or to cards
suspended on central gymbals, I arrange the needles preferably of an
uneven number, one below the other in the same vertical plane. I
prefer to use only two such assemblages of needles disposed on both
sides of the cap for the pivot so as to balance each other. I prefer to
use the lozenge or rhomboid shape of needles contracting from the
middle to the two ends; but I may also use other shapes, such as
the parallelogram or flat bar needle, in which case I prefer to cut
notches in its ends. I also make the ring for carrying the card of
aluminium instead of brass or copper.
In adapting my Invention to the tubular compass, I prefer either
to string a number of short needles on the tube, and keep them apart
with thin washers of aluminium or ebonite, so that they all lie in
the same vertical plane, being held by a nut at bottom, or I dispose
them in two vertical planes on either side of the tube, which I make of
aluminium.
In adapting my Invention to an axis compass I similarly string a
number of such short needles on the axis one above another in the
same vertical plane. Several modes of carrying this out will suggest

page_text: themselves. I can give the axis a square or similar shape so as to fit
into a similar hole in each needle, or I can drill a hole in each needle
to be filled with a brass rivet, which I subsequently tap for the screwed
axis; or when I arrange the needles edgewise one above another, I may
form a vertical central slot in the axis, the needles being held by screws,
or pins, or otherwise..
With liquid compasses I also arrange a number of needles below each
other in the same vertical plane.
I sometimes prefer to use needles of different lengths, but in all cases
I form systems of needles disposed above each other in the same vertical
plane or planes. I use by preference the lozenge or rhomboid shape,
or a shape contracting from the middle to the ends, and I always keep
the different needles out of immediate contact with each other, preferably
by means of aluminium washers or distance pieces. I take cast steel
as the material for my needles, preferably cast steel with a high per-
centage of carbon and alloyed with titanium or boron. Such needles
I harden before magnetisation in a solution of sal ammioniac, after which
I boil them in linseed oil over the fire for about ten minutes;
I prefer
to magnetise needles by placing each end on the opposed poles of two
electro-magnets. These two electro-magnets are connected together at
their opposite ends by means of a soft iron bar or anchor. The needle
is then magnetised by being rubbed on all its edges by a third magnet,
preferably an electro-magnet. The electric coils are so disposed on the
two cores of the electro-magnets that one end of the needle lies on a
north pole and the other end on a south pole. That half with its end
lying on the south pole is rubbed with the south pole of the moveable
magnet, while the end lying on the fixed north pole is rubbed with the
moveable north pole. I then test each needle with a very small mag-
netic needle or with iron filings, in order to see whether it has any
internal cracks or solutions of magnetic continuity. .
I use an ordinary card of talc, which I stiffen or prevent from warping
by means of a ring of aluminium or a ring of ebonite, I may also use
a card made of solid plate of aluminium. Instead of using a compass
bowl of copper, I make it of that alloy of tin, lead, copper, and zinc
known under the name of pewter; I also suspend the central weight
usually fixed on the bottoms of compass bowls from a universal. joint or
from a ball-and-socket joint or from gymbals.

page_text: In order to obtain a steering compass as free as possible from local
attraction, I in the first place raise the steering wheel as high from the
deck as is convenient in the particular ship, and I adapt my system
of constructing compasses to a vertical card, or a card in which the
points are marked on the outside of a zone.
I may also use a particular form of steering compass so arranged as
to have the magnets as far as possible above the level of the deck, and
yet with its card as close as possible to the eye of the steersman. On
a vertical axis or spindle I arrange a number of powerful needles one
above the other; this axis or spindle consists of a very light tube of
aluminium prolonged for some distance down to about the level of the
eye of the steersman and turning in a step. At about this part of the
spindle there is fitted to it the compass card which is preferably connected
to the spindle by means of central gymbals.
In order to prevent the deviation of mast head compasses, the fittings
in their neighbourhood, such as the goose necks for suspending the com-
passes, the chair for the gaff, or the yoke, or the jack stay, are made of
gun metal. Now I find that I can use cheaper mixtures than gun metal
for these purposes.
One of these alloys consists of 45 per cent. of zinc,
50 per cent of copper, and 5 per cent. of wrought iron. I find that a
mixture of from 20 to 30 per cent. of manganese destroys the capability
of getting polarised of cast iron, and that a mixture of antimony has
a similar effect on wrought iron. These proportions must be varied with
different kinds of iron.
These materials may also be used for steering compass binnacles
in preference to wood, and also in combination with wood. Such
binnacles I make with a joint below near the level of the deck, on a
similar mode of construction to the funnels of some steamers. By this
means I can lower the binnacle out of the way while the ship's cargo is
being stowed away.
These improvements also relate to a novel process for preventing
the compass deviations usually produced by that magnetic state of
the hull and other portions of iron vessels which is caused during
building.
The needle of the ordinary mariner's compass being a magnet delicately
poised in order that it may set itself to the magnetic meridian of the
earth is necessarily deviated or tends to be deviated by any magnetism

page_text: in the hull or other parts of the vessel. The magnetism which is excited
on the iron and steel of the vessel during construction is that known to
be the most dangerous in its effects on the needle, on account of its
progressive diminution and consequent variability, while the magnetism
induced in the iron hull by the earth's magnetism has little or no
influence on a properly placed needle, or can at any rate be easily
corrected.
Now it is well known that masses of iron can be magnetized, and by
action in a contrary direction can be yet more easily demagnetized, by
means of any one of the following four processes :-First, magnetism
can be induced in a neutral mass of iron by bringing it in contact
with a magnet; secondly, by striking it with a magnet; thirdly, by
means of mechanical vibrations, or also by heat undulations undergone
by the mass of iron while under the influence of magnetism which is
induced by process No. 1.
The first process is claimed in its application to iron vessels in
Provisional Specification No. 227, A.D. 1866; and the second in the
Complete British Specification, No. 227, A.D. 1866.
The third process is the action usually undergone by iron vessels,
necessarily always subject to the earth's magnetism, and by which they
are known to acquire magnetism in building and to progressively lose
most of it in course of time after launching, thereby rendering useless
the tables of errors or the compensating magnets by which it is sought
to correct the original deviations found in swinging such ships.
The fourth process consists in causing electric currents to encircle
the mass of iron inducing magnetism at right angles to the direction
of the electric currents. It is this fourth process, and the means of
carrying it out, which I claim in their practical applications to the
direct demagnetizations of iron vessels and of any of the portions of or.
on such vessels, such as the steering gear. I first of all survey the
magnetic state of such an iron vessel and its parts by means of a
magnetic needle, in order to determine the appropriate direction of
the magnetism to be temporarily excited in the hull. In the case of.
the hull I then temporarily encircle the ship, preferably around and
at right angles to the longitudinal axis of the hull, with an insulated
wire or wires composed of any of the metals known to conduct electricity
and insulated by any of the known means for insulating such conductors.
This insulated wire may either be laid in a continuous and regular spiral

page_text: round the ship, or it may be laid in irregular spirals connected together,
or in rings afterwards connected together by any of the usual means.
An electric current either continuous or interrupted is then conducted
through this spiral; while the current is on I bring the core or cores
temporarily under its action into as violent a state of vibration as is
possible, this I do in the case of the ship by starting the engines, and in
the case of any part by means of blows from a hammer. This electric
current is either produced in any one of the ordinary galvanic batteries,
or by means of any magneto-electric induction apparatus, such as that,
for instance, described in Specification No. 3209, A.D. 1866. The
current of the galvanic battery can either be employed directly, or
it may serve to induce a current by means of an induction apparatus,
such, for instance, as that known under the name of Ruhmkorff's
induction apparatus.
A rheostatic apparatus, a commutator or any apparatus, by which
the currents of electricity can be regulated and suddenly stopped or
changed in their direction may be employed. I prefer to operate on
the hull of the ship while on the stocks or building slip, or in dry dock
or otherwise accessible. In case, however any such iron ship requiring
to be so treated be afloat, the wire can he carried under the hull by
divers, or slipped under the hull in the form of open rings, which are
afterwards united together by any of the known means for uniting such
wires. The same operation can if found necessary be carried out on any
other parts, such as the steering gear or any beams employed in the
construction of the vessel.
This process may also be combined should it ever be found necessary
with that according to which the separate plates composing the hull
or the other parts of or on the ship are rubbed with a permanent electro-
magnet.
When electro-magnets are used in carrying out this frictional process,
I prefer to employ magneto-electric machines, such as those previously
described for producing the currents in the spirals of such electro-
magnets.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Arthur Paget in the Great Seal Patent
Office on the 11th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
ARTHUR PAGET, of 1, Seymour Chambers, York Buildings, Adelphi,
in the County of Middlesex, Civil and Mechanical Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of March, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Frederick Arthur Paget, Her special
licence that I, the said Frederick Arthur Paget, my executors, adminis-
trators, and assigns, or such others as I, the said Frederick Arthur
Paget, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 CONSTRUCTING SHIPS' COMPASSES AND THEIR
BINNACLES, AND IN PREVENTING THE DEVIATIONS OF COMPASSES IN IRON OR STEEL
SHIPS," upon the condition (amongst others) that I, the said Frederick
Arthur Paget, 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 Frederick Arthur Paget, 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, that is to say :-
These improvements relate, firstly, to a novel mode of constructing
steering or binnacle, standard or surveying, and mast head compasses,
whether for sailing or steam ships, as also compasses for life and other
boats. From the small ratio of the mass and moment of inertia of my

page_text: compass card to its magnetic moment, and also from its low centre of
gravity, it is delicate enough to be used in the finest weather, while
at the same time an identically similar card can be employed in a storm,
or at the mast head, or in a boat. The shortness of its needles also
brings it into favourable conditions in iron vessels as regards deviation.
These improvements are applicable to all kinds and constructions of
compasses, whether to those mounted on a pivot with a common
suspension cap, or to those termed "tubular" compasses in which
the cap and card are fixed to a tube loosely encasing the stem of the
pivot, or those in which an axis is used somewhat similar to that of
the balance wheel of a chronometer, or to those in which the needles
are immersed in a liquid, such as water or spirits of wine, and buoyed
up by a float, and to all other constructions. Instead of using several
needles arranged parallel to each other in one horizontal plane I employ
two or more short needles disposed one above another in a vertical plane
or planes.
In adapting this part of my Invention to, for instance, such cards as
the well-known Admiralty observing and storm cards, or to cards
suspended on central gymbals, I arrange the needles, preferably of an
uneven number, one below the other in the same vertical plane. I
prefer to use only two such assemblages or columns of needles disposed
on both sides of the cap for the pivot so as to balance each other. I
prefer to use the lozenge or rhomboid shape of needles contracting from
the middle to two ends. But I may also use other shapes, such as the
parallelogram or flat bar needle, in which case I prefer to cut notches
in its ends. I also make the ring, when such is used, for carrying the
card of aluminium instead of brass or copper.
In adapting my Invention to the tubular compass I prefer either to
string a number of short needles on the tube and keep them apart
with thin washers of aluminium or ebonite so that they all lie in the
same vertical plane, being held by a nut at bottom; or I dispose them
in two or more vertical planes on either side of the tube. In this last
case I, by preference, employ the form of needle known to compass
makers as the "bar edge," being a needle placed with its top and
bottom edge in the vertical plane. The different needles are united to
one another and to the tube or card by means of plates and screws of
aluminium. When I employ two such assemblages or columns of
needles I place them at such a distance from the centre as to form two

page_text: chords, each about 30° from the 'parallel diameter. When I employ
four such assemblages of needles I place them respectively at 15° and
45° on each side of the parallel diameter. I make all the parts of the
tube of aluminium instead of brass.
In adapting my Invention to an axis compass I similarly string a
number of such short needles on the axis, one above another, in the same
vertical plane. Numerous obvious modes of carrying this out will
suggest themselves. I can give the axis a square or similar shape so
as to fit into a similar hole in each needle, or I can drill a hole in each.
needle to be filled with a brass rivet, which I subsequently tap for
the screwed axis; or when I arrange the needles edgewise, one above
another, I may form a vertical slot in the axis, the needles being held by
screws, or pins, or otherwise. Such assemblages or columns of needles
I can balance in the ordinary way by means of counterweights adjustable
on screws tapped into or otherwise fixed to the tubular or solid axis,
and at right angles to the longest dimensions of the needles forming
the columns or assemblages.
I construct as follows another form of compass which I find gives
good results on shipboard as regard quickness or delicacy in a calm
and steadiness in a storm, while it is less or not at all deviated when
placed at a relatively less distance from magnetic matter than ordinary
compasses :-I take the ordinary axis compass having the bottom of its
bowl fitted with a step or pivot and a bush at top for the top end of
the axis and with or without the usual arrangement for lifting the card
off the step at the bottom when it is required to stop such card. I make
the central axis by preference of aluminium, either solid or tubular,
and into the bottom end of such axis I screw a pivot, and into the
top another pivot or bearing. Near or about the vertical centre of
the intended two or more columns or assemblages of needles I tap an
aluminium screw crosswise into the axis. On this screw and on both
sides of the axis I fix by means of small nuts a vertical bar or bars of
aluminium of a square section; when I use only two assemblages
of needles, one on either side of the axis, I take two such bars; when
I use four assemblages of needles I take four such bars. I then
take a number of short thin magnets about one-and-a-half or two
inches long and thirty-six or twenty-four, more or less in number,
and fix them edgewise in pairs, with their flat sides against the bar,
by screws and nuts or rivets, or otherwise, to the vertical bars, thus

page_text: obtaining a number of pairs of needles or magnets arranged above
each other in the same vertical plane or planes. The card I by preference
fix between the needles, being held in its proper position by being
threaded by or passed through by the vertical bars, which latter are
also steadied by means of a cross piece of aluminium preferably placed
just above and on the card. All the needles are kept out of contact
with each other at a distance of about one-sixteenth of an inch.
Each column or assemblage of needles, when one pair of columns is
employed, is about 30° from the parallel diameter; when two pairs
of columns are used they are so placed as to form chords 15° and 30°
from the parallel diameter.
With liquid compasses I also arrange a number of needles below
each other in the same vertical plane or planes.
I form a compound needle for a common compass with one single
central needle in the following way:-I take a number, four to six,
more or less, of thin lozenge-shaped or rhomboidal needles nearly as
broad as they are long; these I unite together in any of the usual
ways, keeping them preferably about one-sixteenth of an inch apart by
means of aluminium or ebonite washers. In order to counterbalance
this assemblage of rhomboidal needles I adjust pieces of lead, preferably
in the form of rivets, on either side of the smaller transverse diameter
of the set.
In order to approximately obtain the benefits attending the use of
short needles a compound needle might also be formed out of a number
of other short ones, preferably of the rhomboidal shape, such compound
needles being arranged in the usual way on the card but with their
longitudinal axes at right angles to the meridian, that is to say, such
transverse compound needles may be arranged on the card as follows:-
When two only are used each one is set at 30° from the parallel
diameter; when four are used, at 15° and 45° respectively, I should
interpose aluminium washers between the small needles, out of which
such transverse compound needles are built up, keeping the whole
together by means of a screw of aluminium; or an arrangement of rather
short magnets capable of propelling a small card, whether on an axis
or a tube; or a common cap might be made by uniting together in
the same horizontal plane and preferably kept out of contact by washers
of aluminium or ebonite about one-sixteenth thick, a number of broad
needles of such relative lengths as to form chords of one same circle.

page_text: But both these two last combinations are much inferior in usefulness
and efficiency to those previously described above.
It will now be seen that the leading feature of my system of con-
structing ships' compasses consists in the employment of a considerable
number of short needles. I prefer to use the lozenge or rhomboid shape,
or a shape contracting from the middle to the ends, though I may also
use the parallelogram or edge bar needle. I prefer to place such needles
edgewise as above described, and I always keep the different needles
forming the compound needles out of immediate contact with each
other, preferably by means of aluminium washers or distance pieces.
I take cast steel as the material for my needles, preferably cast steel
with a high per-centage of carbon and alloyed with titanium or boron.
Such needles I harden before magnetisation in a solution of sal ammoniac,
after which I boil them in linseed oil over the fire for about ten minutes.
I prefer to magnetise my ships' compass needles by placing each end
on the opposite poles of two electro-magnets.
magnets are connected together at their opposite ends by means of a
soft iron bar or anchor. The needle is then magnetised by being
rubbed on all its edges by a third magnet, preferably an electro-magnet.
The electric coils are, on well-known principles, so disposed on the two
cores of the electro-magnets that one end of the needle lies on a north
pole and the other end on a south pole. That half with its end lying
on the south pole is rubbed with the south pole of the moveable magnet,
while the end lying on the fixed north pole is rubbed with the moveable
north pole. I then test each needle with a very small magnetic needle
or with iron filings in order to see whether it has any internal cracks
or solutions of magnetic continuity.
These two electro-
I use an ordinary card of talc, which I may or may not stiffen or
prevent from warping by means of a ring of aluminium or a ring of
ebonite; I may also use a card made of a solid plate of aluminium.
Such cards of aluminium I stamp or corrugate out with raised designs
representing the usual points of the compass.
Instead of using a compass bowl of copper I make it of that alloy
of tin, lead, copper, and zinc, known under the name of pewter.
In order to obtain a steering compass as free as possible from local
attraction, I in the first place raise the steering wheel as high from
the deck as is convenient in the particular ship. And I adapt my
system of constructing compasses to the kind of card known as a vertical

page_text: card, or a card on which the points are marked on the outside of
a zone.
I may also use another form of steering compass, so arranged as to
have the magnets as far as possible above the level of the deck, and
yet with its card as close as possible to the eye of the steersman. On
a vertical axis or spindle I arrange a number of powerful needles one
above the other. This spindle consists of a very light hollow tube of
aluminium, prolonged for some distance down to about the level of
the eye of the steersman and turning in a step. At or about this part
of the spindle there is fitted to it the compass card, which is preferably
connected to the spindle by means of central gymbals.
In order to prevent the deviation of mast head compasses, the fittings
in their neighbourhood, such as the chain for the gaff, or the yoke, or
the jackstay, and goose necks for suspending the compasses, are made
of gun metal. Now cheaper mixtures than gun metal can be used for
these purposes. One of these alloys consists of 45 per cent. of zinc,
50 per cent. of copper, and 5 per cent. of wrought iron. A mixture
of from 20 to 30 per cent. of manganese destroys the capability for
getting polarised of cast iron, and a mixture with antimony has a similar
effect on wrought iron; these proportions must be varied with different
kinds of iron. These materials may also be used for steering compass
binnacles in preference to wood, and also in combination with wood.
Such binnacles I make with a joint below near the level of the deck
on a similar mode of construction to the funnels of some steamers. By
these means I can lower the binnacle out of the way while. the ships'
cargo is being stowed away.
In witness whereof, I, the said Frederick Arthur Paget, have
hereunto set my hand and seal, this Eleventh day of September,
in the year of our Lord One thousand eight hundred and sixty-