HAVING REFERENCE TO THE MARINERS' COMPAQQ
Year: 1862

page_text: LETTERS PATENT to Edward Samuel Ritchie, of Brookline, in the State
of Massachusetts, of the United States of America, for the Invention of
"HAVING REFERENCE TO THE MARINERS' COMPAQQ"
"HAVING REFERENCE TO THE MARINERS' COMDACG"
Sealed the 24th February 1863, and dated the 13th November 1862.
COMPLETE SPECIFICATION filed by the said Edward Samuel Ritchie at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 13th November 1862, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN, that I, EDWARD SAMUEL RITCHIE, of Brookline, in the State of
Massachusetts, of the United States of America, have made a new and useful
Invention "HAVING REFERENCE TO THE MARINERS' COMPASS," and do hereby
declare that the nature of my said Invention, and the manner in which it is
to be performed, or is constructed and made to operate, are described in the
following Specification, the said Invention being represented in the accom-
panying Drawings making part of such Specification.
The purpose of the Invention is not only to dispose of a mariner's compass
out of or more or less beyond the attractive influence of iron on or about the
deck or other part of a ship or navigable vessel, but to enable the movements

page_text: or operations of the compass card, or the magnet or magnets of the compass
to be easily read or indicated either at, or near, or below the deck, or at any
convenient distance below the compass.
My said Invention is applicable to liquid compasses, and particularly to
such as are provided with an air vessel combined with the magnet, or the
same and its card in manner so as not only to encompass the magnet and
insulate it from the surrounding liquid, but also to buoy up the magnet or
magnets and card, in order to remove more or less of the weight thereof from
the supporting pivot or bearing.
The nature of my said Invention consists in the combination of an auxiliary
annular air vessel or indicator and a connecting rod or mechanical equi-
valents therefor with the magnet or magnets, or the same and its or their
buoyant air vessel, the whole being arranged within a case or vessel to contain
water or other proper fluid, and so as to operate together, substantially as herein-
after specified.
And the nature of my Invention further consists in the combination of either
or both of the buoyant air vessels with their shaft by means of gimballs or
their mechanical equivalents.
And the nature of my Invention further consists in the combination of an
auxiliary buoyant chamber or its equivalent with the said connecting rod or
connecter, the magnet, or the same and its buoyant case, and the auxiliary
case or indicator, as arranged within a vessel or case-containing a liquid, and
so as to operate therein, substantially as herein-after specified.
And the nature of my Invention further consists in a peculiar arrangement
of the cardinal divisions or indications, with respect to the float or indicator
when made either circular or cylindrical in form, or as an annulus, substantially
as described.
Of the said Drawings, Figure 1 denotes my Invention or apparatus as
exhibited in side elevation, while Figure 2 represents a vertical, central, and
longitudinal section of it; Figure 3 is a top view of the magnet buoyant
vessel, the vertical connecting shaft or rod, and a set of its gimballs connecting
the two; Figure 4 is a top view, and Figure 5 a side elevation of the auxiliary
float or indicator; Figure 6 is a horizontal section of the magnet, float, or
buoy.
The external vessel or case A, as shown in the Drawings, may be supposed
to be composed of two hollow closed vessels a, b, and a tube c connecting the
bottom of one (viz. a) with the top of the other (6) of them, and opening
into both of them in order that water or a fluid when poured into the upper

page_text: vessel a may pass freely through the tube c and from thence into the vessel 6.
The said vessel 6 I usually construct cylindrical in form, and with its sides of
à transparent material, such as glass, for instance, in order that the contents
of such vessel (6) may be seen by looking through its sides. These two
vessels a and b, with the tube c, are to contain water or other proper liquid,
which should stand in the vessel (a) nearly up to its top.
A rod or shaft B extends axially within the vessel or case A, and is pivotted
or supported by suitable bearings at its two extremities, the same being seen
at d, d, in Figure 2. This shaft may be tubular, or be composed in part of a
tube e closed at its two ends, and constituting an air chamber or vessel of
sufficient capacity to buoy the shaft in the liquid of the vessel A in such
manner as to cause it to bear with little or no pressure on its lower pivot or
bearing. By constructing the shaft tubular and buoyant, as specified, it is
not liable to be bent or sagged when the apparatus is in an inclined position,
or during the motions of a ship while the said apparatus may be in use on
board thereof.
Within the vessel a, and concentric with the shaft B, there is an annular
float, buoy, or buoyant vessel D, within which there should be arranged one
or more bar magnets g (see Figure 6). There is also another such float or
buoyant vessel E arranged within the vessel b, and concentrically with respect
to the shaft B.
Each of the said floats D, E, is to be connected with the shaft B by a set
of gimballs h. There is to be no magmet within the vessel E, whose buoyant
power should be sufficient or about so to counterbalance the tendency of the
said vessel and its set of gimballs to sink downward in the fluid of the vessel.b.
The buoyant power of the float D should suffice also to counterbalance the
tendency of it and its set of gimballs to sink in the fluid of the vessel a.
Furthermore, I form on either the upper or under surface of the float E, or
down along its external curved surface or periphery, or on either or all the
lines or cardinal divisional marks indicative of the points of compass, the
same being as shown in Figures 4 and 5.
I do not confine my Invention to the particular form of the indicator Eas
it may be otherwise constructed and yet serve its main' purpose or object,
viz., that of indicating the movements and position of the magnet or magnets;
nor is it essential to my Invention that the part D should always be made as
a hollow vessel, as there are other ways in which it may be made in order to
give support to the magnet or magnets, and to perform the function of main-
taining them in a horizontal position within the fluid of the vessel a. The

page_text: tube c may be of any length which according to circumstances may be
necessary to carry the magnets for all practical purposes a sufficient distance
above metallic body which
any
be at or near the deck or other part of a
navigable vessel.
may
When in use my apparatus is intended to be affixed to the mast or some
other suitable part of a ship or navigable vessel, and so that while the part b
may be sufficiently near the deck to allow of the divisions on the part E being
easily seen by a person when on deck, the part a may be at such an altitude
above the deck as will practically remove the magnets out of the influence of
the attractive power of any iron on or near the deck.
It will be observed, that during the rolling as well as during the pitching
motions of the ship the two floats or air vessels D, E, by the operation of
gravity, will preserve their horizontal positions, and this notwithstanding their
connecter or shaft B may be inclined more or less to the horizon; in the
meantime the gimballs and the shaft constitute such a connection of the
two parts D, E, that any rotary motion of the upper one occasioned by its
magnet or magnets will be attended by a corresponding movement of the lower
one, or that marked E.
In constructing the apparatus, I prefer to make the magnet buoyant
vessel the tubular part of the shaft or axis, and also the lower buoyant vessel
or indicator in such manner that each, as nearly as practicable, shall be of
the same weight as the volume of the liquid used or displaced thereby.
Having thus described my Invention, what I claim is as follows:-
I claim the combination of the auxiliary annular air vessel or indicator (E)
and the connecting rod (B), or mechanical equivalents therefor, with the
magnet or magnets (9), or the same and its or their air-tight or buoyant
case (D), the whole being arranged within the vessel or case (A) to contain
water or other proper fluid, and so as to operate together, substantially as
above specified.
I also claim the combination of either or both the buoyant air vessels
(D, E,) with their shaft or rod B by means of gimballs h, or their mecha-
nical equivalents, with the shaft or rod B arranged and supported within a
case A, substantially in manner and so as to operate as described.
I also claim the combination of an auxiliary buoyant chamber or vessel (e),
or its equivalent, with the rod or connecter (B,) the magnet, or the same and
its buoyant case (D), and the auxiliary case or indicator E, as arranged
within a vessel or case (A) containing water or other proper fluid, and so as
to operate therein, substantially as herein-before specified.

page_text: I also claim the improvement of arranging the cardinal divisions in the
external curved surface or periphery of the circular indicator (E), substantially
as specified.
In witness whereof, I have hereunto set my hand and seal, this 24th
October 1862.
EDWARD SAMUEL RITCHIE. (L.S.)