IMPROVEMENTS IN DUMB COMPASSES AND IN APPARATUS CONNECTED THEREWITH, SUCH APPA- RATUS BEING APPLICABLE TO OTHER PURPOSES. PROVISIONAL SPECIFICATION
Year: 1873

page_text: LETTERS PATENT to William Storey Croudace, of Dundee, in the
County of Forfar, North Britain, for the Invention of "IMPROVEMENTS
IN DUMB COMPASSES AND IN APPARATUS CONNECTED THEREWITH, SUCH APPA-
RATUS BEING APPLICABLE TO OTHER PURPOSES.
PROVISIONAL SPECIFICATION left by the said William Storey Croudace
at the Office of the Commissioners of Patents, with his Petition,
on the 17th March 1873.
I, WILLIAM STOREY CROUDACE, of Dundee, in the County of Forfar,
5 North Britain, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN DUMB COMPASSES AND IN APPARATUS CONNECTED THEREWITH,
SUCH APPARATUS BEING APPLICABLE TO OTHER PURPOSES," to be as follows, that
is to say:

page_text: On the Coast may NO
than hitherto.
The Invention also consists in the construction of an apparatus for
lighting the lamp of my improved compass on deck in the windiest
weather, such apparatus being also applicable for lighting other lamps t
on the decks of ships at sea or in the open air in windy weather.
In carrying out my Invention I apply on the outer circumference of
the compass card a toothed wheel into which gear two pinion wheels
placed within the compass bowl; the axles of these pinion wheels pass
through the necks of the gimbals supporting the compass, and have
milled heads fitted to their outer ends; by turning these milled heads
the compass card can be turned in a steady and uniform manner without
disturbing the perpendicularity of the compass, and this arrangement
allows of the compass card being enclosed under a glass cover or dome
to protect it from the effect of rain or spray. In the bowl of the compass 1
I place a lamp (so arranged as not to be extinguished by the action of
the wind) for illuminating the compass card, which I make of frosted
glass, thus enabling observations to be taken and read off during the
night without the aid of an outside lamp; the heated air and products
of combustion from the lamp are carried off through a chimney, the
base of which is fitted to the centre of the compass card; the chimney
is covered with wire gauze at the top, and is provided with a ventilating
ring. Tubes are fitted into the bottom of the compass bowl for the
supply of air to the lamp. In the door of the compass bowl is a circular
plate of glass provided with a moveable screen. Over the chimney on 2
the compass card I fit a hollow standard to which is hinged a moveable
style, whereby the azimuth of the sun may be observed at any altitude.
I employ the known indicator and pointer, the indicator is fitted by
means of a collar provided with set screws to the base of the hollow
standard, and the pointer is fixed on a joint at the top of the standard
above the chimney.
My improved apparatus for lighting the lamp consists of a metal tube
furnished with a portion of the composition used in Bryant & May's
patent match holder. A match holder is provided to fit into this friction
tube. To light the lamp in the compass bowl without opening the door,

page_text: a match (Bryant & May's by preference) is placed in the holder, and
the match and holder passed into the friction tube, which is then inserted
through a hole in the compass bowl provided for the purpose; by
pushing the holder rapidly through the friction tube the match will be
lighted and may be applied to light the wick. This apparatus may be
employed for lighting other lamps on deck or in the open air on land in
windy weather.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Storey Croudace in the Great Seal Patent
Office on the 16th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
STOREY CROUDACE, of Dundee, in the County of Forfar, North Britain,
send greeting.
year
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of March, in the
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Storey Croudace, Her special
licence that the said William Storey Croudace, my executors, adminis-
trators, and assigns, or such others as I, the said William Storey Croudace,
my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN DUMB COMPASSES AND IN APPARATUS CONNECTED, THEREWITH, SUCH
APPARATUS BEING APPLICABLE TO OTHER PURPOSES," upon the condition
(amongst others) that I, the said William Storey Croudace, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said William Storey Croudace, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawing
hereto annexed, and to the figures and letters marked thereon, that is to
say:-
This Invention consists in improvements in the construction of dumb
compasses, whereby bearings at sea of any celestial object or of a light
on the coast may be taken at night in a more ready, correct, and easy
manner than hitherto.
The Invention also consists in the construction of an apparatus for
lighting the lamp of my improved compass on deck in windy weather,
such apparatus being also applicable for lighting other lamps either
on the decks of ships at sea or on land in the open air in windy
weather.
In carrying out my Invention I apply on the outer circumference of
the compass card a toothed wheel or rack, into which gear two pinion
wheels placed within the compass bowl. The axles of these pinion
wheels pass through the necks of the gimbals supporting the compass,
and have milled heads at their outer ends. By turning these milled
heads the compass card can be turned in a steady and uniform manner
without disturbing the perpendicularity of the compass; and this
arrangement allows of the compass card being enclosed under a glass
cover or dome to protect it from the effect of rain or spray. In the
bowl of the compass I place a lamp for illuminating the compass card,
which I make of frosted glass or mica, thus enabling observations to be
taken and read off during the night without the aid of an outside lamp.
The heated air and products of combustion from the lamp are carried off
through a chimney, the base of which is fitted to the centre of the
compass card. The chimney may be provided with a ventilating ring,
or diagonal holes may be made for that purpose. Tubes are fitted into
the bottom of the compass bowl for the supply of air to the lamp.
In the door of the compass bowl is a circular plate of glass provided
with a moveable screen. Over the chimney on the compass card I fit
a hollow standard, to which is hinged a moveable style, whereby the
azimuth of the sun may be observed at any altitude.

page_text: I employ the known indicator, and fit it by means of a collar pro-
vided with set screws to the base of the hollow standard. The pointer,
which is fixed on a joint at the top of the standard above the chimney,
is provided at its outer end with a triangular mirror, and at its inner end
with a spherical lens and a shield.
My improved apparatus for lighting the lamp consists of a metal
tube split and flattened at the outer end, the inner surface of the flattened
part being roughened to form a friction surface. A match holder is
provided to fit into this friction tube.
To make my Invention better understood I will proceed to describe
the same by reference to the accompanying Drawing, in which
Figure 1 is a front elevation of my improved dumb compass, the top of
the wooden box being removed, and the front of same turned down
on its hinges; Figure 2, plan of same; Figure 3, vertical section of
the compass detached from the wooden box, the upper part of the
standard with the pointer not being shewn; Figure 4, plan of the
interior of the compass bowl; Figure 5, plan of the compass card;
Figure 6, plan of screen over the compass card; and Figures 7, 8, and 9,
views shewing the apparatus for lighting lamps. Figures 1 to 6 are
drawn to a scale of about one-third full size, and Figures 7, 8, and 9
full size. Similar letters in all the Figures represent similar parts.
a, a, is the toothed wheel or rack (on the compass card 6) gearing
into the pinion wheels c, c; d, d', are the milled heads placed outside
the gimbal ring c¹, and at the outer ends of the axles of the wheels c, c,
e, e, is the glass dome or cover fitted into the bezzle e³ fixed to the
compass bowl by the screws e³. fis the lamp placed inside the compass
bowl e¹ f¹, reflector; g, chimney fitted to the centre of the compass
card b; g, uptake of chimney, having a conical guard g² in the centre to
prevent the lamp being blown out by a down draught; h, h, are the air
tubes in the bottom of the compass bowl; h³, door of compass bowl,
having a circular plate of glass h²; i, moveable screen for covering or
uncovering the glass h³ as required; ³, knob for moving the screen;
j,j, is the hollow standard formed in two parts. The upper part ¹ is
fitted to the lower part j by means of pins in the upper part ¹ fitting
into sockets in the lower part j. The lower part j of the hollow stan-
dard passes through the glass dome e, and is provided at this part with

page_text: the india-rubber band or collar p. To the collar k at the base of the lower
part of the moveable standard is fitted by means of set screws the
indicator 1. m is the pointer fixed on a joint at the top of the upper
part of the standard; m³, screw for fixing the pointer when set; n,
spherical lens with shield n² at the inner end of the pointer. The light
from the lamp passes through the opening A, Figure 6, in the screen r
to the lens, the shield n preventing the lens dazzling the eyes. n¹ is
the triangular mirror jointed, as shewn, to the outer end of the pointer;
o, guide or incidence bar jointed at one end to the lower part of the
mirror, and at the other end to the standard j¹. This mirror is provided
with a hinged cover with a slit n³ at its apex, and collects the rays of
light from the lamp at whatever angle the pointer may be placed, and
throws the light along the entire length of the pointer, thus enabling
the sight of the eye to be directed from the lens n truly along the bar of
the pointer in the darkest night; 9 is the style hinged to the base of
the
upper part j¹ of the hollow standard for obtaining the sun's azimuth
at any altitude; q³, pinching screw on collar of standard to fix the
standard when in position; r, card screen inside the dome, moving with
the standard and serving to prevent the light dazzling the eyes. This
screen is cut away at each side at A, B, (as shewn in Figure 6, which
is a plan of the screen) to allow of reading off the bearing from the
compass card below, and to allow of the light passing from the lamp to
the lens and mirror. I prefer that the glass dome should be painted of
a dark color all round up to or a little above the level of this screen,
or the dome may be made of metal. s, s¹, chimney guards on top of
standard; t, hole in the door of the compass bowl (closed by a stopper
or plug) for the introduction of the apparatus for lighting the lamp.
The front of the wooden box in which the compass is suspended is
hinged at and to the bottom of the box, so that it may be let down as
seen in Figure 1, and air holes c are made round the sides and back of
the box. On each side of the box I provide two claws z, z, hinged to
the sides of the box at z¹. When the compass is placed on deck these
claws are turned down, and their ends catching into the deck will hold
the box and compass, and prevent it being moved from its place by a
sudden roll of the ship.

page_text: flattened out as shewn, the inner faces of the flattened part being milled
or roughened, or the part u¹ may be formed separate and be fixed to the
tube u.
Into this tube fits the match holder (shewn detached in
Figure 9), made in two parts. The part D has a pricker D¹ at its upper
end (which screws into the other part E), and is formed with a slit at
its lower end for the purpose of receiving and holding the end of a
match 9. This pricker serves to allow of pricking up the light without
having to remove the lamp from its case. For this purpose the pricker
is unscrewed and reversed, and then screwed into the part E. For
lighting lamps on land the match holder is formed without the pricker.
To light the lamp by this improved apparatus a match is placed in the
end of the holder v, and the match and holder passed into the friction
tube u, which is then inserted into the compass bowl through the hole t.
By pushing the holder v rapidly through the friction tube u the match
will be lighted, and may be applied to the wick of the lamp for lighting
the same.
It will be understood that by using this apparatus the lamp
can be lighted on deck in any weather.
I will now describe the method of using my improved compass for
observing the bearing of a star, that is to say, I place the compass with
the lubber's point in a line with the ship's keel; I take out the bearing
of the star from the star azimuth tables corresponding to the latitude
and the apparent time at ship on the particular date; I slacken the
pinching screw q¹ and turn the standard round with the finger and
thumb until the indicator over the compass card 6 coincides with the
given bearing; I tighten the pinching screw q¹ to keep the indicator /
over the bearing, then with one hand on each of the milled heads d, d²,
I turn them (and thereby the compass card 6) until the star comes in a
line with the pointer m. The compass card 6 will then shew the true
direction of the ship's head, the lamp f in the compass bowl illumi-
nating the dial and allowing the bearing to be read off on the darkest
night without necessitating the aid of an outside lamp. By raising the
screen i by turning its knob ¹ the lamp will also give sufficient light
through the glass plate ³ to allow of taking out the bearings from the
azimuth tables without dazzling the eyes.
To observe the bearing of the sun I place the compass with the

page_text: from the sun's azimuth tables and turn the standard as before described
until the indicator coincides with the given bearing; I tighten the
pinching screw q¹ and turn down the style 9 on to the glass dome or
cover e (if the sun's altitude be high), and then turn round the compass
card by means of the milled heads d, d¹, until the shadow from the style q
corresponds with a vertical line marked on the lower part j of the
standard. The compass card will then shew the true direction of the
ship's head. If the sun's altitude be low the style q should be placed at
an angle of about 45 degrees (as shewn in dotted lines Figure 1) so that
the shadow will fall on a vertical line on the upper part ; of the 1
standard.
To observe the bearing of the land or a light the lubber's point must
be placed in a line with the ship's keel and the compass card turned to
the true direction of the ship's head. I slacken the pinching screw q¹
and turn round the standard j, j, until the pointer m is in a line with 1
the cape or other point of land or with the light, and the indicator / over
compass card 6, will then shew the true bearing of the object.
the
Having now described my said Invention and the best means I am
acquainted with for carrying the same into effect, I wish it to be under-
stood that I do not confine myself to the precise details herein laid 2
down, as the same may be varied without departing from the peculiar
character of my Invention; but what I claim is,―
Firstly. The general arrangement and construction of dumb com-
passes, as herein-before described and represented in the accompanying
Drawing.
Secondly. The construction of dumb compasses with a translucent
compass card illuminated by a lamp placed inside the compass bowl, as
herein-before described and represented in the accompanying Drawing.
2
Thirdly. The employment of a toothed wheel or circular rack and
pinions for moving the compass card, substantially as herein-before a
described and represented in the accompanying Drawing.
Fourthly. The employment of a pointer provided at one end with a
spherical lens and shield and at the other end with a mirror, as herein-
before described and represented in Figures 1 and 2 of the accompanying
Drawing

page_text: Fifthly. The improved apparatus for lighting lamps in windy weather,
substantially as herein-before described and represented in Figures 7, 8,
and 9 of the accompanying Drawing.
In witness whereof, I, the said William Storey Croudace, have
hereto unto set my hand and seal, this Fifteenth day of Sep-
tember, in the year of our Lord One thousand eight hundred and
seventy-three.