IMPROVEMENTS IN SIGHTING ORDNANCE, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1880

page_text: LETTERS PATENT to Lothian Kerr Scott, Captain in Her Majesty's Royal
Engineers, of the Junior United Service Club, Charles Street, Saint James',
for an Invention of "IMPROVEMENTS IN SIGHTING ORDNANCE, AND IN THE
APPARATUS EMPLOYED THEREIN."
PROVISIONAL SPECIFICATION left by the said Lothian Kerr Scott at the
Office of the Commissioners of Patents on the 22nd March 1880.
LOTHIAN KERR SCOTT, Captain in Her Majesty's Royal Engineers, of the Junior
United Service Club, Charles Street, Saint James', London. "IMPROVEMENTS IN
SIGHTING ORDNANCE, AND IN THE APPARATUS EMPLOYED THEREIN.”
The nature of my Invention consists in the application of the revolving principle
of the telescopic sight, already patented by me No. 31/77, to sights without
telescopes.
Before I invented the system of sighting ordnance for which I hold Patents it
was not appreciated by artillerists that the errors of shooting due to the inclination
of the sights from the gun wheels resting on an uneven platform could be corrected
by giving a revolving movement to the backsight alone, so as to render it capable
of being brought back at will into a vertical position.
It was known however that these corrections could be made by a revolving
movement provided the backsight and foresight were both made to revolve.
I found out that these corrections already mentioned could be made accurately
by making the backsight alone to revolve, provided that the system of sighting
were so attached to the gun "that the axis of revolution of the back sight and the
tip of the foresight be in a line parallel to the axis of the gun."
Although the above principle is embodied mechanically by me in the telescopic
sight for which I hold a Patent No. 31/77,
I now apply for a Patent for sights made on the same principle without a telescope,
which sights are far less complicated, less delicate, and less expensive, and more
suitable for the ordinary requirements of the service.
The revolving backsight without a telescope consists of a hinged flap and slider
attached to an arm, which are made to revolve together around a hollow centre by
means of a slow motion screw working in the sides of a frame which fits into or is
attached to the gun.
If the revolving movement is applied to the present service sights (back) the flap
is dispensed with. The movement takes place in a vertical plane at right angles to
the horizontal plane passing through the axis of the gun.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Lothian Kerr Scott in the Great Seal Patent Office on the 21st
September 1880.
LOTHIAN KERR SCOTT, Captain in Her Majesty's Royal Engineers, of the Junior
United Service Club, Charles Street, Saint James', London. "IMPROVEMENTS IN
SIGHTING ORDNANCE, AND IN THE Apparatus EmpLOYED THEREIN."
My Invention relates to improvements in sighting ordnance, and to the
apparatus employed therein. These improvements consist in making sights for
ordnance capable of revolution about an axis parallel in every direction to the axis of
the gun. The position of this axis about which the sights are to revolve is the zero
elevation. This revolving movement may be created by automatic arrangement on
the principle of the pendulum, with the centre of gravity of the system of sighting
below the axis of revolution; or it may be created by mechanical adjustment with
the centre of gravity of the system of sighting above tho axis of revolution.
The object of my Invention is,-I. To dispense with the errors of fire due to the
inclination of the service sights when the gun wheels are not on the level, by
making the sights (back or fore) capable of being turned back again into the same
position with reference to the vertical which they occupied when the gun wheels
were on the level.
II. To enable the firer to correct errors in range and direction by mechanical
adjustinents, instead of by the present method of calculation. III. To give the
firer complete command over the axis of the piece under all conditions.
IV. To simplify the instruction required to be imparted to the gunner for the
use of the service sights, by converting mentally calculated arithmetical corrections
for "deflection" into mechanical adjustment.
V. To supply sights containing the abovenamed advantages at a moderate cost.
The said improvements may be applied to all natures of ordnance, whether rifled or
otherwise, as well as to those especially constructed to embody this Invention.
The principle of my system of sighting consists in giving to sights a third
movement in addition to the two movements already existing in the present systein
of sighting. The two movements of the present sights consist in a horizontal
movement for giving " deflection," and in a vertical movement for giving the "angle
of elevation." The additional third movement in my system of sighting consists in
causing the two above mentioned movements of the service sights combined to
revolve about an axis parallel in every direction to the axis of the gun, and
the point of revolution must be the zero elevation of the sights (back and fore).
No sight without these three above mentioned movements, involving as they do
the theoretical principles necessary for a truc sight for guns, will give the firer
complete command over the axis of the piece.
I have therefore embodied these essential theoretical principles mechanically in
sights for ordnance generally, and I designate sights made on these principles
"revolving sights." I will now proceed to describe how I have applied these
principles mechanically in the two examples illustrated in the accompanying
Drawings. Fig. I. shews the front elevation of a revolving backsight fitting into
the socket in the gun of the service sight together with the interior construction of
the same; Fig. 11., the side elevation of the same; Fig. III. shews the front
elevation of the revolving bush if my principle of sighting be applied should it
be desirable to utilize the oxisting "tangent sight"; Fig. IV. is the plan of
Fig. III.; Figs. V. & VI. are the front and side elevation of a service "tangent
sight." F, F, Fig. (1.) is a hinged flap graduated for different ranges, and fitted with
a slider (H, H,) also graduated for "deflection," which can be set at the proper

page_text: elevation on F, F; T is a traveller containing the notch N and eye hole E of the
backsight, which can be made to travel by the screw D for the purpose of giving the
required "deflection." The flap F, F, Figs. (I. & II.) is hinged to an arm (K, K)
both of which are made to revolve together around a hollow centre (C) by turning
5 the screw (W), for the purpose of dispensing with the inclination of the sight when
the gun wheels are not on the level. The hollow centre (C) and the lovelling
screw (W) are fixed to the frame (M, M); (A) is the clamping screw of tho
slider (H,H); (G) in Figs. (I. & II.) is the stem of the sight fitting into the
socket in the gun; (L) is a level to adjust the verticality of the sights, and is fixed
on the sight in a position at right angles to the axis of tho piece. In the case
where the revolving movement described is applied to the servico sights, as in
Figs. (III. & IV.), (B, B,) is a bush centred by a pin (O) which revolves in a frame
(ZZ) attached by a ring (R, R) or otherwise to the gun. In this bush (B, B,) is a
socket into which the service "tangent sight," Figs. (V. & VI.) is dropped when it
is to be used. The bush (B, B,) is made to revolve round its contro by means of the
Screw W and by the spring (S) which presses the spring P against the side of the
bush. The bush (B, B,) is steadied by a flange moving in a circular groove cut in the
frame (Z, Z). The spring (S) is kept in position by a screw cap with a hole in the
centro through which tho pin P works; (A) is the clamping screw to keep
the "tangent sight" at any required elevation; (L) is a level fixed to the tangent
sight, or to any other part of the backsight at right angles to the axis of the
picce.
To use the Revolving Sight.-1, adjust the slider H, H, Fig. I., or tangent scale,
Fig. (V.) to the elevation required; 2, level the hinged flap (F, F) or the bush
(B, B) Fig. III., by turning the screw (W) till the bubble of the level L rest in the
centre; 3, take a line of sight along the centre of the notch (in Figs. I. & V.) of
the backsight and the tip of the foresight, and direct by means of the trail on the
object; 4, see that the bubble be in the centre, and if not readjust it; 5, fire;
6, if, for example, the shot do not strike the object but fall to the right, run the
gun up, level the sight, aim correctly as before at the object, then move the
traveller (T) of the slider (H, H,) (or the eye piece (E) of the tangent sight) by means
of the screw (1)) to the left, until the notch, the tip of the foresight, and the point of
impact of the shot are in line. This operation corrects mechanically the error in
direction of the shot, and shows at once the amount of "deflection" to be given to
the axis of the gun to enable it to hit the mark at which it is aimed. It is there-
fore only necessary to turn the gun laterally by means of the trail, and to aim at
the object with this corrected line of sight, and the shot will travel in the required
direction.
Having thus fully described my said Invention and the manner of performing
the same, I wish it to be understood that I claim,-
1. The principle generally of making sights for ordnance to revolve automatically
on the principal of the pendulum, or by mechanical adjustment with the zero
clevation of the sights as centre, about an axis coincident with or parallel to the
axis of the gun in every direction.
II. The method of attaching sights to guns in such a position that the
mechanical corrections already described in the body of the Specification for
inclined wheels can be accurately inade by the application of my revolving
principle to one of the sights (i.c., to the backsight alone or to the foresight alone).
1II. The method of dispensing with the inaccuracies of fire due to the inclination
of the service sights when the gun wheels do not rest on the level, by making the
backsight or tho foresight alone to revolve about an axis parallel in every direction
to the axis of the gun.
IV. The method of being able to adjust by level, plumb line, or pendulum woight
attached to the system of sighting, the vertical plane containing the "line of sight"
nto any required position with reference to the vertical plane containing the axis
of the gun.

page_text: V. The method of being able to mako by mechanical adjustment all the
corrections which have to be made by calculations for the service sights.
VI. The mechanical method employed in making the sights to revolve, whether
it be applied to the service sights, or otherwise.
VII. The method of making an eye piece consisting of a horizontal and vertical
slit in the top and bottom of a box, as shewn at E, Figs. (I. & II.)
In witness whereof, I, the said Lothian Kerr Scott, have hereunto set my
hand and seal, this Twentieth day of September, in the year of our Lord
One thousand eight hundred and eighty.
T
T SCOTT Cant BE (LS)