IM- PROVEMENTS IN MARINERS' COMPASSES, AND IN APPLIANCES USED IN CONNECTION THEREWITH, FOR INDICATING DEVIATIONS FROM THE SHIP'S TRUE COURSE."
Year: 1879

page_text: LETTERS PATENT to Henry Augustus Severn, of No. 9, Earl's Court Square,
South Kensington, in the County of Middlesex, for the Invention of "IM-
PROVEMENTS IN MARINERS' COMPASSES, AND IN APPLIANCES USED IN CONNECTION
THEREWITH, FOR INDICATING DEVIATIONS FROM THE SHIP'S TRUE COURSE."
PROVISIONAL SPECIFICATION left by the said Henry Augustus Sovern
at the Office of the Commissioners of Patents on the 17th January 1879.
HENRY AUGUSTUS SEVERN, of No. 9, Earl's Court Square, South Kensington,
in the County of Middlesex. "IMPROVEMENTS IN MARINERS' COMPASSES, AND
IN APPLIANCES USED IN CONNECTION THEREWITH, FOR INDICATING DEVIATIONS
FROM THE SHIP'S TRUE COURSE."
My Invention has for its object to provide means whereby any deviation between
optional limits from the prescribed course of a vessel at sea is indicated to the
captain or officer in charge by means of an audible or visible signal at any con-
venient part of the vessel, so that he may at once be apprised thereof, and thus
the danger or loss of time attendant on the ship's continuing for a length of time
on a wrong course unnoticed be obviated.
For this purpose I avail myself of the practically stationary position of the card
of the compass in respect to the magnetic meridian, and of the changing position of
the box or binnacle surrounding the card as it shifts with the vessel, in order to
cause certain electrical contacts to be made when the vessel devintes to a certain
extent from its course, and by such contacts I cause an electrical circuit to be closed
in which is included an audible or visible signal actuated by the current, means
being provided for shifting such contacts at will to any point of the circumference
of the binnacle, or to prevent their occurrence altogether when not required.
According to the arrangement which I prefer to employ, the compass card is sup
ported upon a metal point, which is insulated from the metallic part of the bowl and
gimbals, and is connected to the one end of a wiro circuit, in which is included a
battery and a signalling apparatus actuated thereby, and the other end of which
circuit is electrically connected to a spindle passing centrally through the glass lid
of the compass. The spindle is held in the lid so as to be rotatable therein, and
beneath it, it has a metal arm or index projecting radially from it, so that such index
can be turned by means of its spindle to any point of the compass. A second such
metal index is fixed to a metal sleeve, fitting the spindle so as to be rotatable
thereon, and also passing through to the outside of the lid, so that both indexes can

page_text: be set independently to any desired angular position relatively to each other by
means of the spindle and the sleeve. The centre of the compass card on which the
metal point bears is also of conducting metal insulated from the needles themselves,
but in electrical connection with a metal contact piece or arm projecting from the
upper face of the card, by preference at the north point thercof. The before
mentioned indexes have suspended loosely from them small pieces of platinum wire,
so that whenever by the rotation of the bowl in one direction or the other as it
shifts with the vessel the one piece of wire or the other comes in contact with the
arm of the card, the electrical circuit will be closed and the current will actuate
the signal.
Thus in operating with this apparatus, after the captain or officer has determined
the course of the ship he sets the two indexes so that each one is one or more points
away from each side of the contact arm of the compass card, the amount depending
upou the limits within which a deviation may be allowed. Should now the course
of the ship be altered to the extent of such limit the before described contact will
be made, and the officer will be apprised thereof by the actuation of the signal.
The above arrangement may either be applied to the ship's compass at the helm,
in which case after the indexes have been set the external buttons for them
may be enclosed by a locked glass cover, or the arrangement may be applied to a
special compass in the captain's or officer's cabin, in which case the whole apparatus,
including the battery and the signalling apparatus, may conveniently be enclosed in
a portable box.
By preference an electric alarm bell is employed as the signalling apparatus, and
in this case two bells of different sound may be provided, one for indicating the
deviation in one direction and the other for that in the other direction.
When it is only desired to indicate the deviation of the ship's course in one
direction the second index may be turned out of the way, or both indexes may bo
capable of being raised so that their pendant wires cannot make contact with the
arm of the card when no signalling is desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Augustus Severn in the Great Seal Patent Office on the
26th June 1879.
HENRY AUGUSTUS SEVERN, of No. 9, Earl's Court Square, South Kensington, in
the County of Middlesex. "IMPROVEMENTS IN MARINERS' COMPASSES, AND IN
APPLIANCES USED IN CONNECTION THEREWITH, FOR INDICATING DEVIATIONS FROM
THE SHIP'S TRUE COURSE."
My Invention has for its object to provide means whereby any deviation between
optional limits from the prescribed course of a vessel at sea is indicated to the
captain or officer in charge by means of an audible or visible signal at any con-
venient part of the vessel, so that he may at once be apprised thereof, and thus the
danger or loss of time attendant on the ship's continuing for a length of time on n
wrong course unnoticed be obvinted.
For this purpose I avail myself of the practically stationary position of the card
of the compass in respect to the magnetic meridian and of the changing position of
the box or binnacle surrounding the card as it shifts with the vessel, in order to
cause certain electrical contacts to be made when the vessel deviates to a certain
extent from its course, and by such contacts I cause an electrical circuit to be closed
in which is included an audible or visible signal, actuated by the current, means
being provided for shifting such contacts at will to any point of the circumference
of the binnacle, or to prevent their occurrence altogether when not required.
According to the arrangement which I prefer to employ the compass card is
supported upon a metal point, which is insulated from the metallic part of the bowl
and gimbals, and is connected to the one end of a wire circuit, in which is included
a battery and a signalling apparatus actuated thereby, and the other end of which
circuit is electrically connected to a spindle passing centrally through the glass lid
of the compass. The spindle is held in the lid so as to be rotatable therein and
beneath it, it has a metal arm or index projecting radially from it so that such
index can be turned by means of its spindle to any point of the compass.
A second
such metal index is fixed to a metal sleeve fitting the spindle so as to be rotatable
thereon, and also passing through to the outside of the lid, so that both indices can
be set independently to any desired angular position relatively to each other by
means of the spindle and the sleeve. The centre of the compass card in which the
metal point bears is also of conducting metal, insulated from the needles themselves,
but in electrical connection with a metal contact piece or arm projecting from the
upper face of the card, by preference at the north point thereof. The before-
mentioned indexes have suspended loosely from them small pieces of platinum wire,
so that whenever by the rotation of the bowl in one direction or the other as it shifts
with the vessel the one piece of wire or the other comes in contact with the arm of
the card, the electric circuit will be closed and the current will actuate the
signal.
Thus in operating with this apparatus after the captain or officer has determined
the course of the ship, he sets the two indexes so that each one is one or more points
away from each side of the contact arm of the compass card, the amount depending
upon the limits within which a deviation may be allowed. Should now the course
of the ship be altered to the extent of such limit, the before described contact will
be made, and the officer will be apprised thereof by the actuation of the
signal.
The Invention may either be applied to the ship's compass at the helm, in which
case, after the indexes have been set, the external buttons for moving them may be
enclosed by a locked glass cover, or the arrangement may be applied to a special
compass in the captain's or officer's cabin, in which case the whole apparatus,
including the battery and the signalling apparatus, may conveniently be enclosed in
a portable box.

page_text: Fig. 1 of the accompanying Drawings shews a plan and Fig. 2 a vertical section
of a mariner's compass with my before described Invention applied thereto.
The compass card A has a metal centre A¹, which rests on the metal point B, and
has a metal arm A³ projecting from it over the upper surface of the card, preferably
at the north point. The point B is insulated at B₁ from the bowl, and has connected
to it the one end of the circuit wire C leading to the battery E and electric bell or
other signalling apparatus F, the other end of the circuit wire being connected at
C¹ to the gimbals D of the compass. From the lid G of the compass, which is in
electrical connection with the gimbals D, a metal wire or strip H (represented by a
dotted line) passes across the glass to the centre, where it is electrically connected
to the metal socket I fixed in the glass. Through this socket passes a tubular metal
piece K, having at its outer end a button K' and on its inner end a metal arm K³,
from which is loosely suspended a piece of thin platinum wire Ks; through the
tubular piece K passes a metal rod L, having a button L, and on its inner end a
metal arm L³, from which is suspended the platinum wire L³. The tube K. being
free to turn in the socket I, and the rod L being free to turn in the tube, while all
three are in electrical contact with each other and with the metal strip H, it will be
seen that the arms K and L2 can be set to any desired angle on either side of the
arm A³, and that should the bowl be turned in the one direction or the other
relatively to the card A to such an extent as to cause the arm A to come in contact
with the one or the other of the wires K³ or L³, the electric circuit formed by the
wire C will be closed, and consequently the bell or other signal at F will be actuated.
Thus assuming that the captain or officer in charge, after determining the course on
which the ship is to be kept, sets each of the armis K, L, to an anglo on either side
of the arm A corresponding to the limits within which a deviation from the
prescribed course may be allowed, then on these limits being exceeded a contact
will be made and a signal given as above described, whereby the captain or officer
will be apprised of the fact. The tube K, together with the rod L, can slide up and
down through the socket I, so that when it is not desired to use the apparatus the
arms K, L, can be raised sufficiently to lift the wires K³, L³, out of the reach of
the arm A, or the one or the other of the arms may alone be raised when it is
desired to indicate the deviations of the ship's course in one direction only, as before
mentioned. It will be readily understood that in place of the battery at E any
other convenient source of electricity, euch as a small magneto electric machine, may
be employed for producing the requisite current.
In order to provide two bells or other signals, one for indicating the deviations to
port and the other for those to starboard, as before mentioned, two separate electrical
circuits, with a battery and signal, would be required, the one circuit being con-
nected to the tube K with its arm K, and the other being connected to the rod L
with its arm L³, while the other terminal of both circuits would be connected to the
point B. In this case the tube K and rod L would of course have to be insulated
from each other. Instead of providing only one bell in the electrical circuit or
circuits there might be provided two or more at different parts of the ship, such as
in the captain's cabin and in the cabin of the second officer, so that each might be
apprised of the deviations from the prescribed course.
It will be evident that numerous other modifications might be adopted for
carrying my Invention into practico; thus each of the arms K and L might be

page_text: made to constitute the two insulated terminals of either a single electrical circuit
common to both, or of two separate circuits, and the compass card be simply
provided with a contact piece, which in coming in contact with the two terminals
of the one or other arm, would close the circuit and give the desired signal.
Also in place of having the two arms connected to the centre of the compass lid,
they might be carried by slides capable of being shifted round the inner circum-
ference of the compass bowl; but I prefer the arrangement above described as being
the most simple.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,-
First. The construction of mariners' compasses wherein an arm or contact piece
carried by the compass card operates in combination with one or more adjustable
insulated arms or contact pieces carried by the compass lid or bowl, and connected
to an electrical circuit, in which is includod one or more electrical bells or other
electrical signals, so that the arm or contact piece on the card in being brought in
contact with the one or other arm on the lid or bowl will close the electrical circuit
and cause a signal to be given, substantially as and for the purposes herein
described.
Second. The construction of mariners' compasses, the compass card of which has
an arm or contact piece in electrical connection with the one pole of a battery, the
circuit whereof includes a signalling instrument, such arm being made to operate
in combination with one or more adjustable insulated arms carried by the compass
bowl or lid, and in electrical connection with the other pole of the said battery,
substantially as and for the purposes herein set forth.
Third. The combination of the arm A carried by the compass card A and con-
nected to the one pole of a battery E with the two adjustible arms K², L, connected
to the other pole of the battery É and the signalling instrument F, substantially as
herein described.
In witness whereof, I, the said Henry Augustus Severo, have hereunto
set my hand and seal, this Third day of June, in the year of our Lord
One thousand eight hundred and seventy nine.
HENRY A. SEVERN. (L.s.)