Improvements in Magnetic Compasses for use by Night (on Horseback).
Year: 1892

page_text: Date of Application, 22nd Jan., 1892
Complete Specification Left, 21st Oct., 1892-Accepted, 31st Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Magnetic Compasses for use by Night
(on Horseback).
C
1, JOHN JAMES STEWARD, 457 West Strand, London, Middlesex, Optician, do
hereby declare the nature of this invention to be as follows:-
It has been
An instrument consisting of a magnetic needle, preferably the kind known as a
bar needle, to the north end of which is attached a shaped piece of non-magnetizable
metal. The needle is balanced in the way usually employed in what is known as
the horse-back compass, viz.-between two agates, jewels or centres.
The compass
box is made in an improved way with two flat pieces of glass placed above & below
the needle; one of the pieces of glass is painted with, either degrees or points or
both degrees & points. The top glass is protected by a hinged cover, & the bottom
glass, by a cover to remove by unscrewing or other convenient means.
found by experiment that luminous painted paper or card retains its luminosity
longer than metal & by means of the transparent bottom of glass & removable cover,
it can be kept flat in the intervening space & renewed as occasion requires. This
separation from the actual interior of the compass box in which the magnetic
needle swings prevents any chemical action from the luminous paint affecting the
steel or metal of magnetic needle or balance. When in use the luminous substance
employed, is excited by the sun's rays, magnesium light, &c. ; & the needle with
the shaped end, together with the painted points, shew readily against the luminous
back-ground. As the painted points have a stated value, a given course is readily
steered; the balancing (as described) of the needle preventing undue oscillation.
Dated this 21st day of January 1892.
JOHN J. STEWARD.
COMPLETE SPECIFICATION.
Improvements in Magnetic Compasses for use by Night
(on Horseback.)
JOHN JAMES STEWARD 457 West Strand London Optician do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
An instrument consisting of a magnetic needle (compass) preferably that kind
known as a bar needle, to the north end of which is attached a shaped piece of
non-magnetizable metal. The said needle is balanced in' the way usually employed
in what is known as the horseback compass viz. between two agates, jewels or
centres. The compass box containing the magnetic needle is made in an improved
way with two flat pieces of glass or transparent medium, one above & one below
the needle & fixed into the cylindrical side of compass box by a bezel or other
convenient method. The one below forms the bottom of the box and on it is
painted or marked the degrees or points of the compass or both degrees & points.
The glasses or transparent medium or films are protected by covers preferably
hinged to the case of compass box but may be fixed by screwing or any other
usual way of fitting. The lower cover is arranged to receive a disc of luminous
paper which after being excited by sunlight, daylight, or at night by the light
from burning magnesium ribbon or wire will give out sufficient luminosity to show
the needle alluded to above, and a direction bar to be explained hereafter. Stops
are provided for checking the needle from swinging too freely.

page_text: A reference to the accompanying drawings will explain the various parts
alluded to.
Fig. 1 shows a plan of the compass.
A. is the shaped piece of non-magnetizable metal fixed to the magnetic needle.
B. is the direction bar moved from outside the lower glass. C is a luminous paper
strip in the lid or top cover, to act as a finger. Dis one stop pin acting on a
curved piece (D') & D" of sprung (hammered) metal which on being pressed stops
or checks the needle for one portion of its revolution on the pivot and E acting on
another curved metal band E' & 'E", answers in the same way for the opposite
side. F is the cover for top glass or transparent film or medium.
Fig. 2 shows a side view of the magnetic compass, B. being the direction bar for
setting to the required bearing and pivoted at B₁, F the top cover to box & G the
bottom cover.
The needle A is shown pivoted in the agates jewels, or centres A¹ A".
The method of using this compass is as follows:-Supposing it is desired to
march on a certain magnetic bearing say 250°, the direction bar B is turned so as
to be under the division representing 250 degrees on the compass dial, the figures
and points of which read reverse of ordinary compasses, i.e., read from north by
the east to south which is 180 and so on by the west again to north, which is
360 degrees.
The compass is held so that the luminous line in lid of case is in front of
user, then the needle is allowed to settle or if too lively assisted by touching
check stops D. & E. The user without shifting the compass now turns himself
about until the shaped end A. of magnetic needle is over the direction bar. As
soon as this is done the luminous line in lid will point as a finger to the direction
required. Bearings can be taken on a map by using the glass bottom of the
compass box next the map turning the cover aside for the purpose, if hinged as
shewn, so that the degrees & points on it are seen over the map. It is necessary
to first set the direction bar B to the N point on compass dial, painted on the glass
or transparent base, or for true N to 17° westerly variation. Then place the
compass on the N & S line of map (or along edge of or parallel to the edge of an
ordnance map) taking care centre of luminous line in lid & centre of bow of
compass box are in true line, then turn the whole of map until N of the magnetic
needle of compass is over the direction bar. Bearings of roads &c. can now be
seen through the transparent base of compass.
It has been found by experiment that luminous painted paper or card or other
similar substance retains its luminosity longer than luminous painted metal, and
by means of the glass or transparent bottom to compass box & the moving cover
a disc of luminous paper can be kept flat in the intervening space and renewed
as occasion requires. This separation from the actual interior of the compass
box, in which the magnetic needle swings prevents any chemical action from
the luminous paint affecting the steel or metal of magnetic needle or balance
pivots &c.
The needle & points readily show against the luminous back ground, viz. the
luminous card below the painted glass bottom or transparent film having compass
points on, and as the balancing secures extra steadiness and the improved stops
assist in bringing the magnetic needle to rest, this compass will be found useful
for night or day use either on horseback or on foot where quickness of use is
of considerable moment.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The application of a non magnetizable plate of a well defined shape to an
ordinary magnetic needle preferably the kind known as a bar needle.
2. The combination of a glass or transparent film or medium base to a compass,

page_text: with a cover to contain luminous painted paper, card or other suitable material
substantially as described.
3. The improved method of setting the direction bar from outside the trans-
parent base of compass box & below the needle.
4. The improved method of stopping a magnetic needle by which it can be
brought to rest or checked at either side of the compass box while revolving on
its centre as figured & described.
5. A magnetic compass for night marching & general use substantially as
described & figured.
Dated this 21st law of Catahou 1900
JOHN J. STEWARD.