An Improved Method of and Apparatus for Sighting Guns.
Year: 1891

page_text: Date of Application, 24th Oct., 1891
Complete Specification Left, 23rd July, 1892-Accepted, 10th Sept., 1892
PROVISIONAL SPECIFICATION.
An Improved Method of and Apparatus for Sighting Guns.
I, FRANCIS EDWARD DYKE ACLAND late Captain Royal Artillery of 32 Victoria
Street, in the City of Westminster do hereby declare the nature of this invention to
be as follows:-
My invention relates to the sighting of guns and is chiefly designed to facilitate
the aiming of large guns such as are used in turrets or in other enclosed or protected
positions.
The ordinary method of providing for the sighting of objects in the working of
such guns is to arrange thereon a fixed piece called a fore sight and an adjustable
piece called a hind sight and the object is sighted by adjusting a point or line on the
rear sight into coincidence with the object and the fore sight. In some instances
telescopes are used and in other instances reflecting mirrors are provided to permit
the object to be sighted from a position below or separate from that occupied by the
gun; but in any case the gunner or officer must take care to have the object in
the proper relation to the hind and fore sights before firing or giving the order to
fire.
Now according to my invention I provide for the sighting of a gun in a turret or
the like in such a manner that the gunner need only keep his eye on one point, that is
to say on a point in the position occupied by the usual hind sight, and has only to
watch through or upon the surface of a sheet of glass or other suitable material the
appearance of an image of the object of attack. For this purpose I adapt to the
sighting of a gun the principle of the camera; that is to say in place of the ordinary
foresight and hind sight of a gun I use a lens and a surface upon which the image
of the object is cast by the said lens. The lens should be of such a kind as to
ensure production of a clear and distinct image upon the said surface. It is in
some instances fitted in the end of a tube at or near the other end of which is
arranged a sheet or plate of ground glass or other suitably transparent material and
behind the latter a suitable eye-piece is sometimes arranged. The glass or other
plate or sheet is made adjustable by means of micrometer screws or otherwise so
that the said plate or sheet can be readily adjusted relatively to the lens. Or an
attachment may be fitted to the lens by which the focus may be adjusted to any
angle relatively to the plate. I usually mark the transparent surface with inter-
secting lines to indicate the sighting point thereon.
In some instances the gun may be used in a dark turret and then the tube and eye
piece would not be necessary as the image transmitted by the lens would be plainly
visible on the ground glass or other surface. I can use in combination with the said
lens any convenient arrangement of mirrors and can arrange the ground glass or
other sheet or plate in any convenient and protected position, and I can attach it to
existing sights or sighting devices.
Dand shin 24th day of October 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Sighting Guns.
I, FRANCIS EDWARD DYKE ACLAND, of 32 Victoria Street, in the City of
Westminster, late Captain Royal Artillery, 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 :-
My invention relates to the sighting of guns, and is chiefly designed to facilitate
the aiming or laying of large guns such as those used in turrets or in other enclosed
or protected positions.
The ordinary method of providing for sighting in the working of such guns is to
arrange on the gun a fixed piece called a fore sight, and an adjustable piece called a
hind or rear sight, and the object is sighted by adjusting a point or line on the hind
sight into coincidence with the object and the fore sight. In some instances
telescopes are used, and in other instances reflecting mirrors are provided to permit
the object to be sighted from a position below or separate from that occupied by the
gun, but in any case the gunner or officer must take care to have the object in
the proper relation to the hind and fore sights before firing or giving the order
to fire.
Now according to my invention, I provide for sighting in such a manner that the
gunner need not look to see if there is a coincidence of the three points, vi:.:-the object,
and the rear and fore sights, but need only keep his eye on one point, that is to say,
on a point in a position at or near that usually occupied by the hind sight, till he sees
through or upon the surface of a sheet of glass or other suitable material, at that
point, an image or picture of the object of attack. And my said improved method
of sighting consists in the adaptation of the principle of the camera for that purpose,
that is to say, I provide the gun with apparatus consisting essentially of a lens in
combination with a screen which may be a plate or tablet of any suitable material
properly arranged for receiving the rays transmitted through the said lens or prism
and for exhibiting the image or picture of the object thereby produced.
In order that my said invention may be clearly understood I will now proceed to
describe the same with reference to the accompanying drawings, in which:
Figure 1 is a plan of a gun fitted with sighting apparatus according to my inven-
tion adapted for use in a turret,
Figure 2 is a side elevation and
Figure 3 is a muzzle end view of the same,
Figure 4 is a side elevation of a gun fitted with sighting apparatus according to
my invention adapted for use for field or siege purposes.
Like letters indicate corresponding parts throughout the drawings.
With reference first to Figures 1, 2, and 3, A is a lens which is held in a
bracket A secured on the gun; the lens should be of proper dimensions to cast a
clear and distinct image of objects at various ranges on to a screen situated at or
near the rear end of the gun as shewn at B. The said screen is made of ground
glass, parchment, or of other suitable material, and is adjustable laterally and
vertically upon the gun by the following means that is to say :-It is carried upon
a sliding piece C which is adjusted upon a cross bar D by a suitable screw provided
with milled heads E; the said cross-bar is secured to or formed upon the upper end
of a bar F which is adapted to move vertically in a guide G secured to the gun, and
which is adjustable in the said guide by a pinion operated by the milled head H;
both bars are suitably graduated for various ranges and degrees of deflection. The
surface of the screen B should be marked with intersecting lines to indicate the
exact position of the sighting point thereon.
In using this sighting apparatus the screen B is adjusted in accordance with the
range of the object, and the gun is then moved until the image of the object is seen
in proper position upon the said screen.

page_text: A suitable eye-piece containing a magnifying glass, can be arranged in any con-
venient position relatively to the screen B, if desired.
When the sighting apparatus is to be used on a gun in the open, or in any place
which is well lighted, the sighting apparatus must be provided with means for
excluding all light from the screen except those rays which come through the lens,
and I prefer to use for this purpose a "bellows" tube I of leather, india-rubber or
the like extending rearward from the lens to the screen as shown in Figure 4;
the rear face of the screen should be enclosed by a cap J, and viewed through a
suitable opening therein at J, which may, if desired, be provided with a magnifying
lens. Instead of the said "bellows" tube, I may employ a telescopic tube.
When necessary the lens A in my said improved sighting devices is held in a tube
which is adjustable endwise in the bracket A³, so that the focus may be adjusted
relatively to the screen. The screen B is sometimes made adjustable by means of a
micrometer screw or otherwise so that it can be readily adjusted relatively to the lens.
Moreover I can use in combination with the said lens any convenient arrangement
of mirrors or reflectors, so that the image on the ground glass or other screen can
be observed from a concealed and protected position. Or I can attach the screen
to existing sights or sighting devices.
In some instances I may adopt an arrangement wherein the rays of light which
produce the image on the screen are thrown down upon it from a lens-prism, at the
top of a turret or the like.
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. The herein described improved method or system of sighting guns.
2. A sighting apparatus according to my invention, for use upon or in connection
with a gun in a turret or the like, substantially as herein set forth and for the
purpose specified.
3. The modification of my invention substantially as described with reference to
Figure 4, for the purpose specified.
4. My improved sighting apparatus arranged in combination with mirrors or
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.