Improvements in or applicable to Magnetic Compasses or other Instruments in which Dials or Movable Indices are employed.
Year: 1891

page_text: Date of Application, 17th Oct.. 1891
Complete Specification Left, 8th July, 1892-Accepted, 27th Aug. 1892
PROVISIONAL SPECIFICATION.
Improvements in or applicable to Magnetic Compasses or other
Instruments in which Dials or Movable Indices are employed.
I, THEOPHILUS GEORGE HUSBAND NICHOLSON M.R.C.S., of 47 Catherine
Street, Liverpool, in the County of Lancaster, do hereby declare the nature of
this invention to be as follows:-
This invention relates to magnetic compasses, ships' telegraphs and other
instruments in which dials or movable indices are adapted to exhibit their indica-
tions both in day light and in the dark.
The main object of the improvements is to provide luminous white or other dials
which shall be durable and thoroughly efficient in action, the luminosity in the
case of luminous dials being produced by any suitable luminous paint or paste,
preferably of a light colour, so that the readings on the dial may be readily visible
in day light.
I will describe my invention more especially in connection with needle compasses,
though it must be understood that the whole or parts thereof are equally applicable
for spirit compasses and for other instruments.
I propose to form the compass card or dial of xylonite either alone or in
conjunction with talc or other material.
I print the figures, letters, etcetera, on the back of a piece of polished xylonite
or celluloid film, and, when dry, coat the whole surface of the back with luminous
paint and afterwards with a coat of varnish, finally placing a duplicate piece of
xylonite or tale at the back, so as to protect the painted surface and aid in
maintaining a true level. Between the pieces of xylonite is an annular strip of
suitable non-magnetic strengthening material also adapted to keep the dial flat and
prevent it curling. The coat of varnish aforesaid is sufficient to cause the two
pieces of xylonite to adhere, but gutta percha solution or collodion is employed
(if desired to work on one piece) to exclude moisture, and tongues may be provided
These are folded back
on one of the pieces of xylonite for further security.
over the annular strip or flat circular band in position and covered over all with
white enamelled paper or tale. The aforesaid tongues may be as numerous as
desired and may be turned over the back piece as well as over the annular band,
but, by the former method, a neater effect is obtained.
I find that the luminosity of the luminous pigments may be increased by means
of a process of levigation, by which the molecules are infinitesimally divided, and,
in this condition, are more thoroughly exposed to the rays of light, natural or
artificial, causing them the better to vibrate and give forth waves of light.
The luminosity of luminous pigments may be further developed and maintained
at a uniform degree of intensity throughout a night by providing inside the
binnacle of the compass or other receptacle a fine copper or rubber coil with inlet
and outlet taps or without, and connected with a steam pipe or other means by
which the temperature may, if necessary, be raised and maintained at a suitable
degree (say 98 degrees). Should there be any condensation of moisture upon the
window or glass of the instrument, it may be prevented by rubbing a little glycerine
over the inside surface of the glass.
It will, of course, be understood that other forms of dial may be used, and, if a
substance is chosen which is not transparent, it is painted on the top face.
By the adoption of xylonite, the mottled appearance peculiar to talc, together
with the risk of fracture in slitting or printing, is obviated and a clearer effect is
produced.
A similar effect to that produced by hand painting or lithography may be

page_text: obtained by the introduction of black and white in or upon celluloid or xylonite
for the purpose of a plain black and white or non-luminous card.
It will be further understood that pigments or lacquer other than luminous may
be used for the purposes of ships' dials in, upon or under the same material.
Dated this 16th day of October 1891.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
other
Improvements in or applicable to Magnetic Compasses or
Instruments in which Dials or Movable Indices are employed.
1, THEOPHILUS GEORGE HUSBAND NICHOLSON, M.R.C.S., of 47, Catherine
Street, Liverpool, in the County of Lancaster, 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 :-
This invention relates to magnetic compasses, ships' telegraphs, and other
instruments in which dials or movable indices are adapted to exhibit their indica-
tions both in daylight and in the dark.
The main object of the improvements is to provide white, luminous or other dials
which shall be durable and thoroughly efficient in action, the luminosity in the case
of luminous dials being produced by any suitable luminous paint or paste,
preferably of a light colour so that the readings on the dial may be readily visible
in daylight.
I will describe my invention more especially in connection with compass dials
and ships' telegraph dials, though it must be understood that the whole or parts
thereof are equally applicable for spirit compasses and for other instruments.
In the drawings,
Figure 1 is a cross section, and
Figure 2 a plan of a needle compass dial;
Figure 3 is a cross section of a spirit compass dial;
Figures 4 and 5 a front view and cross section respectively of a ship's telegraph
dial.
I propose to form the compass card or dial of xylonite either alone or in
conjunction with tale or other material. In the arrangement shown in Figures 1
and 2, I print the figures, letters, stretera, on the back of a piece of polished
xylonite A, or celluloid film, and, when dry, coat the whole surface of the back
with luminous paint and afterwards with a layer of white enamelled paper, finally
placing a piece of tale B at the back by way of stiffening the dial and aiding to
maintain a true level Between the pieces A and B is an annular strip of suitable
non-magnetic strengthening material a also adapted to keep the dial flat and prevent
curling. The last layer of paint is sufficient to cause the xylonite and enamelled
paper to adhere, but tongues D may be provided on the piece A for further
security. These are folded back over the annular strip or flat circular band C
in position, and covered over all with another layer of white enamelled paper or
talc, preferably the latter as explained. The aforesaid tongues may be as numerous
as desired, and may be turned over the back piece as well as over the annular band,
but by the former method, or a sewing machine stitch, a neater effect is obtained.
The free edge may be sealed with collodion or india rubber solution.
I find that the luminosity of luminous pigments may be developed and maintained
at a uniform degree of intensity throughout a night by providing inside the
binnacle of the compass or other receptacle a fine copper or rubber coil with inlet
and outlet taps or without, connected with a steam pipe or other means by which
the temperature may be raised and maintained at a suitable degree (say 98°).
Should there be any condensation of moisture upon the window or glass of the

page_text: instrument, it may be prevented by rubbing a little glycerine upon the inner surface.
of the glass.
It will of course be understood that other forms of dial may be used, and, if a
substance is chosen which is not transparent, it is painted on the top face.
By the adoption of xylonite, the mottled appearance peculiar to talc, together
with the risk of fracture in slitting or disturbance of the laminations by printing
is obviated, and a clearer effect is produced.
A similar effect to that produced by hand painting or lithography may be
obtained by the introduction of black and white in, upon or under xylonite or
celluloid for the purpose of plain black and white or non-luminous dials, for-
example, telegraph or engine dials.
It will be further understood that lacquers or pigments other than luminous may
be used for the purposes of ships' dials in, upon or under the same material.
In the case of spirit compasses, the dial may be formed of xylonite moulded to.
the required form having the figures, letters, etcetera, painted or worked in, upon
or under the surface and then backed with luminous or other paint, or enamelled
paper, or the copper ones hitherto generally used may be painted with the
luminous paint and the lettering be hand painted over it and protected with an
insoluble varnish.
A very excellent white unbreakable and durable engine telegraph dial is formed
by means of a piece of xylonite A (Figures 4 and 5) at the back of which are.
printed or painted the letters, words, etretera. A piece of white enamelled paper B
is then placed at the back of the xylonite, and behind this again a backing of
strong material such as millboard or the like. The edge is bound all round the
circumference by means of a lip or flange C, and the centre hole is formed by
the flanged piece D. This construction is applicable for compass and other dials
besides telegraph dials.
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. A compass or other dial or movable index formed with the design formed of,.
or thrown up and made observable by, luminous paint or other material, and
protected by xylonite or other material, substantially as described.
2. In connection with a luminous painted dial or index, a copper or other
non-magnetic steam coil or equivalent heating mechanism, so arranged that in cold
weather or in the dark it shall beat the said dial or index and maintain it heated
at such temperature as shall ensure its continued luminosity throughout the night,.
substantially as described.
3. The manufacture of compass cards and telegraph dials in whole or in part
of xylonite, on which the design is painted, printed, or worked in, substantially as
and for the purposes described.
4. The manufacture of engine telegraph or other dials substantially as described.
with reference to Figures 4 and 5.
Dated thin 7th of Jul 1900
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents..