Improvements in or relating to Non-magnetic Compasses or Course Correctors for Mariners' Compasses.
Year: 1892

page_text: Date of Application, 22nd Dec., 1892
Complete Specification Left, 15th Sept., 1893-Accepted, 28th Oct., 1893
-
PROVISIONAL SPECIFICATION.
Improvements in or relating to Non-magnetic Compasses or Course
Correctors for Mariners' Compasses.
I, JAMES MORTON, of Villiers Street South, Sunderland, in the County of
Durham, Nautical Instrument Maker, do hereby declare the nature of this invention
to be as follows:-
My invention has reference to improvements in or relating to non-magnetic or
"dumb" compasses, compass course correctors or indicators, which instruments are
chiefly used to find the error or deviation of the mariners' compass.
In these instruments the card or dial marked with the notations of the mariners'
compass disposed and arranged horizontally, and the objection to this is that it
is not always readily accessible for inspection, and can only be properly illuminated
at night by additional lights or by the use of a transparent plate and transmitted
light.
The objects of my invention are first; to enable the observer to more readily
read the indications of the instrument than heretofore when in an elevated position,
say, at or about the level of the eye as is often convenient in use, and second; to
afford greater convenience of illuminating the graduated dial at night so that it
may (if required) be distinctly visible by the ordinary binnacle light.
According to my invention I arrange the dial of the instrument vertically more
or less for which purpose I use a ring of cylindrical, coned, curved, or other suitable
form, diameter, depth, and material, upon which 1 mark the usual notations or
graduations of the dial of the compass, (instead of on a flat, circular dial as hereto-
fore). This ring is arranged so as to be capable of rotation and it may he mounted
in the usual manner with gymbals or otherwise as desired. The instrument is
fixed in convenient position, preferably about the level of the eye of the observer,
for example, in or upon the top of a ship's binnacle, and the light from the usual
binnacle lamps at night will illuminate, through the centre part, the graduated ring
and render visible the compass points and degrees marked thereon; or the instru-
ment may be used on a separate stand or in a box and with or without lamps as
may be required.
Dated this 22nd day of December 1892
J. C. CHAPMAN,
Agent.
COMPLETE SPECIFICATION.
Improvements in or relating to Non-magnetic Compasses or Course
Correctors for Mariners' 'Compasses.
I, JAMES MORTON, of Villiers Street South, Sunderland, in the County of
Durham, Nautical Instrument Maker, do hereby declare the nature of this inven
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
My invention has reference to improvements in or relating to non-magnetic or
"dumb" compasses, compass course correctors or indicators, which instruments are
chiefly used to find the error or deviation of the mariners' compass.
In these instruments the card or dial marked with the notations of the mariners'
compass is disposed and arranged horizontally and the objection to this is that it
is not always readily accessible for inspection, and can only be properly illuminated
at night by additional lights or by the use of a transparent plate and transmitted
light

page_text: The objects of my invention are first; to enable the observer to more readily
read the indications of the instrument than heretofore when in an elevated position,
say, at or about the level of the eye as is often convenient in use; and secondly;
to afford greater convenience of illuminating the graduated dial at night so that it
may (if required) be distinctly visible by the ordinary binnacle light.
According to my invention I arrange the dial of the instrument vertically more
or less, for which purpose I use a ring of cylindrical, coned, curved, or other suitable
form, diameter, depth, and material, upon which I mark the usual notations or
graduations of the dial of the compass (instead of on a flat circular dial as hereto-
fore). This ring is arranged so as to be capable of rotation and it may be mounted
in the usual manner with gimbals or otherwise, as desired. The instrument is
fixed in convenient position, preferably about the level of the eye of the observer,
for example, in or upon the top of a ship's binnacle, and the light from the usual
binnacle lamps at night will illuminate, through the centre part, the graduated ring
and render visible the compass points and degrees marked thereon; or the instru-
ment may be used on a separate stand or in a box and with or without lamps as
may be required.
In further explanation of my invention I have illustrated same in the annexed
drawings in which Fig. 1 represents an arrangement of the instrument with the
ring dial vertically disposed; and Fig. 2 shows same mounted upon the top of an
ordinary ship's binnacle.
Referring to Fig. 1, A represents the rotary dial ring graduated on its inner
surface in the usual manner; though shewn as vertically arranged its surface may
take any form conveniently adapted for inspection. The ring is connected by
radial arms a. a. to a central boss to which is fitted the depending arm or pen-
dulum W with weight or ball w; above the boss provision is made for applying
when required a sight vane v hinged at v¹ and of usual construction for taking
bearings. The vane standard V by means of a coned joint. such as dotted at v² or
otherwise is capable of turning movement about the centre of the dial ring A upon
the upper end of the lower arm W, and to its base is fixed a plate P graduated in
degrees of easterly and westerly variation and having a concentric slot p. Between
the fixed pendulum W. w. and the movable vane standard V is mounted a rotary
index finger F suitably formed and extending diametrically across the dial ring A,
and a pin fixed thereto passes through the slot p and is provided with a fixing
nut, whereby the plate P can be secured to finger F at any angle corresponding
to the degree of easterly and westerly variation existing at any given place.
The graduated dial ring A is mounted in an outer carrying ring such as B or
otherwise so as to be capable of rotation as required, and the said ring B is hung
in bearings or gimbals b. b. in an outer bearing ring C. This latter is also mounted
in gimbals cc in the casing K or binnacle head, the two sets of gimbals b. b, c. c,
being disposed at right angles to each other so that the dial A will always
maintain a horizontal position, the pendulum W assisting to bring it more rapidly
to rest. is a fixed index finger for denoting the precise position of the dial
ring A. It will be seen that by this arrangement the central parts are open
whereby the light from the usual binnacle lamps L. L, Fig. 2, will always
illuminate the graduated dial A without additional light as heretofore usually
required.
Thus the indications of the compass on any course can by day or night be more
readily read than heretofore especially when it is fixed in an elevated position ;
and also the error or deviation of the compass from the true bearings can be more
readily ascertained.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In non-magnetic compasses or course correctors for mariners' compasses
arranging the graduated dial more or less vortically in the foun
Linstand

page_text: of horizontally as heretofore) substantially in the manner and for the purposes set
forth.
2. In non-magnetic compasses such as above referred to arranging the graduated
dial in the form of a more or less vertically disposed and rotary open-centred
ring such as A, and mounting same substantially as above set forth whereby the
indications and error of the compass can be readily ascertained, and the dial will
be illuminated by the ordinary lights when fixed in the top of a ship's binnacle.
"
3. A. non-magnetic compass or course corrector for mariners' " compasses сод-
structed, arranged, and adapted for use substantially in the manner and for the
purposes hereinabove described and illustrated in the accompanying drawings.
· For the Applicant,
J. C. CHAPMAN,
70, Chancery Lane, London, W.C., Chartered Patent Agent.