AN IMPROVED APPARATUS FOR ENABLING ORDNANCE TO BE POINTED BY NIGHT
Year: 1873

page_text: LETTERS PATENT to William Storey Croudace, of Dundee, in the
County of Forfar, North Britain, for the Invention of "AN IMPROVED
PROVISIONAL SPECIFICATION left by the said William Storey Croudace
at the Office of the Commissioners of Patents, with his Petition, on
the 9th May 1873.
I, WILLIAM STOREY CROUDACE, of Dundee, in the County of Forfar,
North Britain, do hereby declare the nature of the said Invention for
"AN IMPROVED APPARATUS FOR ENABLING ORDNANCE TO BE POINTED BY NIGHT,"
to be as follows, that is to say :—
This Invention consists in the construction of an apparatus or night
sight vane to be applied to the rear end of ordnance, whereby the
altitude, and bearing, or position of any object to be fired at by night can
be ascertained with great facility and accuracy, thus enabling pieces of
ordnance to be pointed truly and rapidly.

page_text: The apparatus is constructed of a cylindrical case, in the bottom of
which is placed a lamp or a candle, the top or cover of the case is formed
partly of glass or mica, having a graduated are round its circumference
and partly of metal; or the top or cover may be entirely of glass or mica,
a chimney is fitted in the centre of the top of the case, over which is
placed a hollow standard, having a pointer and mirror similar to that
described in my Provisional Specification, No. 977, dated 17th day of
March 1873. The sight vane at the inner end of the pointer is formed
with an eye hole or a long sight tube. At the back of the hollow
standard is fitted a quadrant graduated at the back, the outer end of the
pointer works in a central slot of the quadrant, and is provided with a
small swing mirror for throwing the light on the graudations on the
quadrant. An indicator is fixed to the front of the lower part of the
hollow standard, and a screen is also provided moving with the hollow
standard for covering over the glass or mica parts of the top of the case
when the light is not required.
The apparatus is provided with a long stud for fitting into a socket in
the rear end of the gun; in the centre of this stud a spring candle socket
can be fitted.
By means of this apparatus the pointer can be truly directed by night
to any object to be fired at, and its bearing and altitude will be indicated
on the graduated are and quadrant respectively, and will thus allow of
the gun being accurately pointed without shewing a light to the enemy.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Storey Croudace in the Great Scal Patent 2
Office on the 7th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
STOREY CROUDACE, of Dundee, in the County of Forfar, North Britain,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 3
Letters Patent, bearing date the Ninth day of May, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-six.th
year of Her reign, did for Herself, Her heirs and successors, give and
grant unto me, the said William Storey Croudace, Her special licence

page_text: that I, the said William Storey Croudace, my executors, administrators,
and assigns, or such others as I, the said William Storcy 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, tho
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED Appa-
RATUS FOR ENABLING ORDNANCE TO BE POINTED BY NIGHT," 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 Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Storey Craudace, 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 the construction of an apparatus, which I
call an ordnance night sight vane, to be applied to the rear end of
ordnance (or mounted on a box or tripod when used as a collimator or
object finder) whereby the altitude and bearing or position of any
object to be fired at by night can be ascertained with great facility and
accuracy, thus enabling pieces of ordnance either on land or on board
ship to be pointed truly and rapidly.
The apparatus is constructed of a case the upper part of which is of
a conical form and the lower part of a cylindrical form; in the bottom
of the case is placed a lamp or a candle; on the top of the case is a dial
formed partly of glass or mica and partly of metal, or the dial may be
made entirely of glass or mica. A chimney is fitted in the centre of
the dial and over the chimney is placed a hollow standard having a
pointer with a lens and mirror similar to that described in the Specifica-
tion of Letters Patent granted to me, and dated the Seventeenth day of
March One thousand eight hundred and seventy-three, No. 977. At the
back of the hollow standard is fitted a double quadrant graduated at the
back; the outer end of the pointer passes through and travels in the spacc

page_text: between the quadrants. An indicator is fixed to the lower part of the
hollow standard and a screen or cover is also provided moving with
the hollow standard for covering the dial; this screen has two openings
for the passage of the light to the lens and mirror, moveable covers
being provided to close these openings when the apparatus is not being
used.
To improve the action of the apparatus I apply to the back of the
case a metal casing forming a chamber; in the bottom part of this
chamber is fixed a double quadrant, and from the top of the chamber
a pendulum is suspended by a gimballed joint.
The apparatus is provided with a long stem or stud at the bottom
for fitting into the rear end of the gun (or into the box or tripod when
used as a collimator), the said stem is made hollow to receive a spring
candle tube.
Having thus described the nature of my said Invention, I will
now proceed more particularly to describe the means of carrying the
the same into effect by reference to the accompanying Drawing in which
Figure 1 is a front elevation of my improved apparatus drawn full
size, and Figure 2 section of same, the standard and pointer not
being shewn.
The apparatus is constructed of a case a, the upper part of which
is of a conical form and the lower part of a cylindrical form, and having
a square stem b fitting into a corresponding socket in the rear end
of the gun. When the apparatus is used as a collimator this stem
is made round to admit of the instrument being turned in any direction;
in this stem b is fitted a spring candle tube c for holding the candlo
for lighting the apparatus (or a suitable lamp may be employed);
a', a², inner and outer bottoms of the case having holes for ventilation;
in the top of the case is fixed a dial d, shewn also in plan on a smaller
scale at Figure 3; this dial is made of glass or mica, except the central
part d', which is made of metal; a number of brass or other metal
bars & extending from the metal part d' to the outer circumference
of the glass serve for strengthening the same. The dial is marked
all round in degrees as shewn in Figure 3. In the hole in the centre
of the dial is fixed the chimney f, over which is placed a hollow
standard f, having an indicator g, a pointer f², mirror f³, lens j, and
incidence bar f*, similar to that described in the Specifications of my

page_text: said Letters Patent No. 977; h is a swing screen at the back of the
mirror to prevent reflected light being seen in front of the instrument;
i, is a screen to shut out the reflected light thrown on the mirror when
viewed from the spherical lens j at the inner end of the pointer f³
to protect the cyc from reflected light from the mirror. At the back
of the hollow standard is fixed a double quadrant ; the outer end
of the pointer passes between the two parts of the double quadrant
and is provided with a set screw for fixing the pointer at any angle.
In the Drawing the degrees of the quadrant are shewn marked on the
side thereof for the convenience of reference, but in practice they are
marked on the back of the double quadrant; e is a square screen
hinged to the quadrant to shut out the reflected light thrown on the
quadrant from the candle. To the moveable standard ¹ is fixed a
metal screen or cover placed over the dial; a small opening 8, 8¹, is
made on each side under the pointer, through which holes the light
from the candle reaches the mirror f³ and lens j, as shewn in
dotted lines Figure 1, moveable covers t, t, being provided to cover
these openings when the apparatus is not being used; 1, 1, ventilating
tubes in the cover l'; P, cap to prevent light passing through the tubes
, this cap is formed with openings o on its edge for the escape of the
heated air; p, p, shew similar ventilating tubes in the metal portion d'
of the dial d; m is a hinged support to keep the pointer at point blank
representing the gun's axis; when the gun requires to be elevated this
support is thrown back; m¹ is a lock pin for holding the cover, standard,
and pointer at zero or axial line of the gun when required. To the
back of the case a is fixed a smaller metal casing n, with a hinged
door n¹ at back of same provided with a mirror n²; this mirror is placed
opposite the small window p² in the case à; the casing is also provided
with a side door u hinged to the body of the lamp case a.
In the casing n is suspended by a suitable double or gimballed joint
pa pendulum 7 having a leaden bob or ball q', the lower end of the
pendulum passes between the two quadrants placed at a distance
apart as shown in detached view at Figure 4; the quadrants are shewn
marked with degrees on the side thereof, but in practice the degrees
are marked on the upper sides of the quadrants, the joint p' allows the
lower end of the pendulum to swing backwards and forwards between
the quadrants so as to mark the degree of elevation of the gun,
and also allows the pendulum to swing at right angles or laterally with
its cross piece formed with teeth, each tooth representing one degree

page_text: of the arc; this arrangement allows of ascertaining the angle of deflection
or the number of degrees the gun may be from an upright position.
In the case a is made a hole closed by a stopper for lighting the
candle of the apparatus by means of the improved apparatus described
in my said Letters Patent, No. 977.
The mode of using this improved apparatus when suitably fitted to a
The door u being
gun for pointing the same by night is as follows: —
opened the pendulum q will indicate on the quadrant the angle of
elevation or depression and deflection of the gun, and if it be required
to fire at an object with an elevation of 5° the mere movement of the
elevation screw of the gun will be registered by the pendulum and
quadrant, and the gun can be set with great accuracy.
To ascertain the position of a visible object to be fired at the gun
(and thereby the pointer) is first set in a horizontal position by means
of the pendulum q and quadrant (and the screens t, t, should then
be removed from over the openings s, s',) and the light from the flame
of the candle will pass through the said openings and will strike as
shewn by the dotted lines Figure 1 on to the lens j and mirror f
respectively, and will enable the eye to be directed along the pointer f
the support m being thrown back, the lock pin m³ removed, and the set
screws and loosened the pointer fe may be clevated or depressed
and turned until it points exactly towards the object to be fired at;B
the elevation of the object can then be read off from the quadrant k,
(the light reflected from the mirror ² being sufficient for this purpose)
and the bearing of the object from the dial d. The gun is then elevated
or depressed until the pendulum q marks on the quadrant the same
degree as that marked by the pointer f on the quadrant &, and then
turned until it points truly to the object to be fired at according to the
bearing read off from the dial d.
The improved apparatus is also applicable as an object finder or
collimator to aid in laying a gun on an object or given point not
constantly visible, for which purpose it is mounted on a solid box or
a tripod, the stem or stud being made round so as to fit into an adjustable
ball cup on the tripod so that the instrument may be turned round in
any direction.
In naval warfare the instrument should be hung on gimbals when
used as a collimator.

page_text: Having thus described the nature of my Invention and the best means
I am acquainted with for carrying the same into effect, I wish it to
be understood that I do not confine myself to the precise details herein
laid down as the same may be varied without departing from the
principle of my Invention; but what I claim is, the general arrange-
ment and construction of apparatus, which I call an ordance night sight
vane, for enabling ordnance to be pointed by night either on land or on
board ship with accuracy, as hercin-before described and represented
in the accompanying Drawing.
In witness whereof, I, the said William Storcy Croudace, have
hereto set my hand and seal, this Fourth day of November,
One thousand eight hundred and seventy-three.
W*. S. CROUDACE. (L.S.)