Improvements in and relating to the Sighting of Ordnance.
Year: 1894

page_text: Date of Application, 3rd Jan., 1894
Complete Specification Left, 3rd Oct., 1894-Accepted, 3rd Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to the Sighting of Ordnance.
I LOTHIAN KERR SCOTT Lt.-Colonel late Royal Engineers of Forest Lodge
Farnborough in the County of Hampshire England do hereby declare the nature
of this invention to be as follows:-
My improved sight for ordnance is of such a nature that when the telescope of
the sight in its bracket is laid on the target by turning the elevating screw of the
gun, the axis of the gun receives automatically the proper elevation to hit that
target whether the platform on which the wheels of the gun carriage rest be level
or not in fact it is a rangefinder and sight combined worked automatically by
elevating and depressing the muzzle of the gun and with the absolutely necessary
principle that by its special construction it corrects mechanically the errors in
shooting which would be caused by any irregularities in the level of the " racers
of the platform. This kind of sight is specially applicable for guns at an elevation
above the sea, as well as for guns inland on commanding positions above level
ground or ground undulating more or less uniformly over the field of fire.
"
Its employment would render night firing at moving objects illuminated by the
electric beam not only possible but effective because there would be no time lost in
range-finding and in adjusting the sight for elevation by hand, and moreover it
would generally quicken the accurate fire of a group of guns and when necessary
supply each gun with the means of its own independent self-defence.
The following is the manner in which I in a general way embody in mechanical
form the theoretical principles of the above mentioned sight.
6:
A telescope similar to that in use with the Scott telescopic sight (Patent
No. 5053 of 1881) and fitted with a cross and longitudinal level is hinged at one
end to a hollow steel bar. This bar is held in V's on a bracket which is rigidly
fixed to the face of the trunnion of the gun in such a way as to maintain it (i.e. the
bar) always parallel to the axis of the gun, and it is also capable of a rotatory
motion around its longer axis. The angle contained between the axis of the
telescope and that of the steel bar corresponds with what is technically called in
gunnery "the sight angle of elevation" (i.e. the angle made by the line of sight
with the axis of the gun) and it is governed in amount by the movement of a roller
travelling along a range curve" (calculated for the height of the horizontal axis
of the gun above sea level) which is fixed to the upper side of the telescope, and
its surface is kept in contact with the roller automatically by overbalance or
mechanically by a spring attached to the underside of the telescope and pressing
against the bottom part of the guides for the object-glass-end of the telescope to
work in. These vertical guides are rigidly attached to the steel bar. The roller
(which is attached to a tubular piston, containing a spiral spring and working in the
hollow steel bar) is set in motion by the movement of this piston-the piston is set
in motion by the movement of a train of wheels, the teeth of which engage the
teeth of a straight rack, forming part of, or securely attached to the tubular piston
on the side opposite to that of the roller. This train of wheels is geared to a
segmental toothed rack clamped to the carriage, and on elevating or depressing the
gun the train together with the roller is set in motion, but on clamping the train of
wheels and unclamping the segmental toothed rack, the gun can be elevated or
depressed without moving the roller, thereby enabling "quadrantal" elevation
(ie. technically the angle which the axis of the gun makes with the horizon) to be
given to the gun without altering the sight angle of elevation between telescope
and bar.

page_text: On working the elevating screw of the gun the toothed segmental rack which is
securely clamped to the carriage will impart notion to the train of wheels (working
in the face of the trunnion of the gun or in the metal of the bracket attached to
the face of the trunnion) geared to the straight rack, and the roller will by its
movement to and fro along the "range curve determine the angle between the
telescope and the steel bar in other words the sight angle for the range, so that
when the cross wires of the telescope are directed on the water line of the target,
the requisite elevation will be given to the gun to hit it.
To sum up, the sight is made up of four chief parts viz. (1.) The telescope.
(2.) The hollow steel bar or axis of revolution of the sight. (3.) The bracket.
(4.) The multiplying gear.
The telescope has the following parts viz.:
(1.) Diaphragm with horizontal and vertical movement containing horizontal and
vertical pointer inside the telescope together with scale graduated for deflection
and elevation. (2.) A cross level and a longitudinal level. The cross level fixed
at right angles to the axis of telescope, the longitudinal level parallel to the axis
of the telescope but hinged at one end and capable of movement in a vertical
plane. (3.) "Range curve "fixed to upper side of telescope which latter in the
case described is hinged to the steel bar and below it.
The hollow steel bar or axis of revolution of the sight has the following
parts viz.:
(1.) The telescope hinged at the eyepiece-end to the steel bar. (2.) The steel
bar has two cylindrical ends called the "trunnions of the sight" which rest in
the V's of the bracket. (3.) Inside the hollow steel bar is a spiral spring inside
a cylindrical piston which latter can move along the bar. A straight toothed rack
is attached to the upper side of the piston and a roller below on the underside.
Two slits are cut longitudinally in the bar to allow the rack and roller to travel
along it. The spiral spring is to get rid of backlash between the teeth of the
train of wheels, the straight rack, and the curved rack attached to the carriage,
and also to cushion the telescope against the shock of discharge in the event of the
telescope being left on the gun during firing. (4.) Two guides for the object-glass-
end of the telescope to work between are rigidly attached to the steel bar.
the automatic sight is to be used as an ordinary gun sight the telescope must be
made clampable to the guides which can be graduated in degrees or supplied with
a spiral graduated in yards. (5.) For making the steel bar to revolve in the V's of
its bracket, a wheel is fitted to it in such a manner that it can be turned by a
worm shaft working in the metal of the bracket. (6.) The ends of the steel bar
are closed with screw caps or in any other suitable way.
When
The bracket is made in one casting with two projections in which the V's are cut
parallel to the axis of the gun and it is rigidly fixed to the face of the trunnion of
the gun.
The multiplying gear. In order to give the roller a greater movement along the
"range curve than would be obtainable from the movement of the circumference
of the trunnion of the gun, a train of wheels works in the metal of the bracket-
one end of the train is geared with the rack of the piston in the steel bar, the
other end to the segmental toothed rack clamped to the gun carriage. The wheels
and the segmental rack are each capable of being clamped and unclamped at will.
This automatic sight corrects the errors in shooting due (1) to the "rise and fall
of tide" and (2) to the irregularities in the level of "
racers of platforms in the
following manner.
"
For the "rise and fall of tide" in three ways viz.-(a.) By mechanically
increasing the sight angle of elevation, given automatically to the telescope by the
movement of the roller along the "range curve," by raising or lowering the cross
wires up and down a vertical scale inside the telescope. (b.) By supplying
different " range curves made interchangeable with the one fixed to the telescope.
(c.) By using only one "range cuive which has been calculated for high water
level and by directing the telescope above, instead of, on the water line of the

page_text: target for a lower tide to such an extent as is taught by the experience of
practice.
"
The irregularities in the level of the "racers I of the platform are corrected in
the following manner.
Transverse inequalities are corrected by means of the cross level on the telescope
which is levelled by rotating the steel bar of the sight and thereby ensuring the
verticality of the sight.
Longitudinal inequalities are corrected as follows, viz. :
<:
racers"
have been
(1.) The gun is traversed round to a position where the
ascertained to be level, (transversely and longitudinally).
This is recorded by attaching a level permanently to the gun carriage with its
bubble in the centre.
For this datum position the "range curve" is calculated or shaped by actual
practice and consequently the axis of the gun will have in this position the correct
elevation to hit the mark on which the telescope is laid by the elevating screw of
the gun for all positions of the roller on the " range curve."
"
(2.) Level both the cross level and the longitudinal level-the former by the
levelling screw of the sight, the latter by its own screw.
(3.) Clamp the train of wheels and unclamp the segmental toothed rack.
(4.) Traverse the gun into the direction and in front of a target crossing
the line.
(5.) Level both levels (if they have been put out of level by the unevenness of
the "racers")-the cross level by the levelling screw of the sight, but the longi-
tudinal one by elevating or depressing the gun by the elevating gear. By this
means any quadrantal elevation lost or gained by the axis of the gun in its transit
along the "racers," as shewn by the disturbance of the bubble, will have been
compensated for. If now the automatic principle of the sight be brought into
play by clamping the segmental toothed rack to the gun carriage and by unclamping
the train of wheels and the cross wires be brought on to the target by the elevating
gear of the gun, the proper elevation will have been given to the axis of the gun
to hit the mark in spite of any previous loss or gain of quadrantal elevation due to
the irregularities of the "racers."
(6.) Clamp segmental toothed rack and unclamp train of wheels.
(7.) Lay telescope on water line of target by elevating screw of gun or above
water line if the tide be below datum level of " curve.
(8.) Level the cross level by levelling screw of sight, and the longitudinal
level by its own screw.
(9.) Fire.
The levelling of the longitudinal level at this stage (as described in No. 8) serves
to supply the datum level or level of reference for checking and correcting if
necessary the quadrant angle of the gun for the succeeding shot for the same or
any other position of the gun carriage on the "
and it obviates the necessity
for retraversing to a datum position on the " racers on each occasion.
"
racers
"
"
This automatic sight can be used as described above, or (1) by moving the roller
to zero on the " range curve by turning the elevating screw of gun, (2) by
clamping the train of wheels in that position (3) and by unclamping the segmental
toothed rack from the gun carriage, it can be used in conjunction with a graduated
arc or spiral as the ordinary Scott-telescopic sight and be given by hand the
requisite sight or clinometer elevation for ranges communicated from a range-finder
to the gun.
In witness whereof, I, the said Lothian Kerr Scott, have hereunto set my
hand this Third day of January, in the year of our Lord eighteen hundred
and ninety-four

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to the Sighting of Ordnance.
I, LOTHIAN KERR SCOTT, of Forest Lodge, Farnborough, in the County of
Hants, England, Lieutenant-Colonel, late Royal Engineers, 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 improvements in sights for ordnance.
The object of my said invention is to construct a sight which is of such a nature
and is so combined with the gun that all that need be done when laying the gun
is to bring the line of sight upon the object aimed at, no matter at what range the
object may be and which sight, when turned with the gun, effects automatically
the adjustment required for range, provided that an initial adjustment according
to the position of the gun, is properly made. The said sight serves also as a
range-indicator. It is a very important feature of the sight that by its special
construction it can be employed to correct, mechanically, any errors in laying
which may arise by reason of irregularities in the level of the racer of the platform.
My improved sight is particularly useful for guns situated at an elevation above
the sea, and for guns, inland, on commanding positions above level ground or
above ground which undulates more or less uniformly over the field of fire.
The employment of such a sight would render night firing at moving objects,
illuminated by the electric light, not only easy but effective, for in its use there is
no time lost in range-finding and in adjusting the sight for elevation by hand, for
no such operation is needed, and, moreover, would tend to result in the quickening
of accurate fire from a group of guns, and, when necessary, would supply each gun
with the means of its own independent self-defence.
In order that my invention may be clearly understood I will now proceed to
describe the same with reference, by way of example, to the accompanying
drawings, wherein
Figure 1 is a side elevation, partly in section, of one form of sighting apparatus
constructed according to my invention, and of as much of a gun-mounting as is
necessary for the purposes of explanation, and
Figure 2 is an elevation of the same at right angles to Figure 1.
Like letters indicate corresponding parts throughout the drawings.
The said
A is part of the carriage. B is one trunnion of the gun, resting in a bearing on
the carriage. C is the cap of the bearing. D is a frame secured to the trunnion.
D' D' are brackets which extend from the frame D and are provided with jaws.
E is a tube graduated externally, closed at the ends by suitable caps, and held in
the jaws of the brackets D' in a position parallel to the axis of the gun.
tube can be turned in the brackets, about its own axis. El is a worm wheel fixed
upon the tube E, and F is a worm journalled in one of the brackets D' and geared
with the worm-wheel E. F' is a milled head whereby the worm F can be rotated
to turn the tube E in the jaws of the brackets.
Gis a hollow sliding rack provided with teeth G¹ which pass through a slot E²
in the tube E. It is closed at one end by the plug G³, and is movable end wise in
the tube and provided with projections G3 which extend through a slot E³, side by
side, and have a roller G', hereinafter termed a traveller, journalled between them
for a purpose hereinafter specified. The roller may, if desired, be dispensed with
and a projection from the hollow rack employed instead.
H is a rod fixed centrally in the hollow rack G. I is a spring placed between
the plug at the front end of the rack, and the rear end of the tube E, to take
up back-lash in the gearing hereinafter specified, and to keep the tube E pressed
to the rear. The action of this spring I can be reinforced by an auxiliary
spring arranged to act in any suitable manner upon one of the wheels of the

page_text: said gearing. A slight amount of clearance is left between the rear face of the
forward bracket D¹ and the adjacent collar on the tube, to permit the tube to have
a slight end wise movement in the brackets during recoil, so that the spring may
lessen the effect of the shock upon the sighting apparatus. The spring I encircles
the rod H, which serves to prevent it from buckling excessively. Moreover a
spring is placed around the rear end of the tube between the rear cap thereof
and the rear bracket, to assist in neutralizing the shock of recoil.
EE are slotted cheeks which extend down from the tube E and are connected
by a cross-piece E' for a purpose hereinafter specified.
J is a telescope, preferably of the kind described in the Specification of prior
Letters Patent No. 5053 of A.D. 1881 granted to me, and having an internal
pointer and an internal adjustable scale for lateral deflection. It is hinged at J¹ to
the tube E and is fitted with a cross level J, and a longitudinal adjustable level .J³
which can be operated in a vertical plane by the interaction of the spring J' and
adjusting-screw J³.
K is a cam plate, hereinafter referred to as a "
range curve." It is firmly held
in lugs J on the telescope J, and can be replaced by other range curves as may
be desired.
A pin J projects from each side of the object-glass end of the telescope and is
guided in the slots of the cheeks E. The telescope can be fitted with a drum and
spiral graduated in any suitable manner, or with any equivalent device, whereby
the telescope can be adjusted non-automatically between the cheeks E' about its
hinge J, if desired. In this manner it can be used as an ordinary sighting-
telescope in a manner which is well understood by artillerists.
J8 is a spring, attached to the telescope and arranged to bear upon the cross-
piece E to press the telescope upward to keep the edge of the range-curve K
between the projections G³ and in close contact with the traveller G. Or such
contact can be ensured by "over-balancing" the telescope, or otherwise.
The tube E and its attachments can remain on the gun during firing or provision
can be made for disengaging the worm F from the worm-wheel E' so that the tube
can be turned round in the brackets D', together with the telescope, into a position
whence they may be readily lifted out of the brackets before firing. They can
be equally readily replaced with certainty in their former position by a reverse
operation after firing. The teeth of the rack and of the wheel or segment
gearing therewith, are numbered or otherwise marked in correspondence, to
enable proper re-engagement after disengagement to be effected. The said rack
should be clamped and held by any suitable clamping device just before the
telescope is thus lifted out of place. The angle contained between the axis of
the telescope J and that of the tube E corresponds with what is technically called
in gunnery
"the sight angle of elevation," that is to say the angle made by the
line of sight with the axis of the gun, and its amount is governed by the movement
of the roller along the range curve, which curve is calculated for the height of the
horizontal axis of the gun above sea level and is preferably fixed as aforesaid
to the upper side of the telescope. The roller is moved along the tube E
automatically by gear which is operated in the movement of the trunnion relatively
to the carriage, and which is adapted to multiply that movement in order to render
the adjustment and indications of the device less minute than would otherwise
be the case.
The arrangement of the gearing whereby the sights are laid automatically in
the movement of the gun will now be described.
L is a slotted arc fixed to the mounting. M is a segmental rack adjustable in
the slotted arc L. N is a block which is normally kept in contact with the
segmental rack by a lever O pivoted in the arc and adapted to bear on the block N
to clamp the rack thereby, in any position to which the said rack may be adjusted.
For the lever, any other suitable clamping-device can be substituted. The arm of
the lever is elastic so as to spring into place behind a stud L' at one extreme of
its movement.

page_text: Where the gun-platform is permanently level the rack M need not be made
adjustable, but can be permanently fixed to the carriage.
P and Q are non-rotatable spindles supported in the upper part of the frame D,
and in the front plate D2 forming part thereof. Upon the spindle P are journalled
the wheel P and segment P2, which are in one piece or are otherwise firmly
secured together. Upon the spindle Q are journalled the wheel Q' and the
segment Q2, which also are fixed together. The wheel P₁ gears into the rack M,
the segment P2 gears into the wheel Q' and the segment Q2 gears into the teeth of
the rack G.
R is a nut, screwed on to the spindle Q and provided with a handle R' whereby
it can be operated to move the spindle endwise, to jam the wheel Q¹and segment Q
against the inner face of the plate D³, to prevent them from rotating when it is
desired to lock the train of gearing.
On moving the gun by means of the elevating screw, the movement of the train of
gearing P1, P2, Q1, Q2, with the trunnion, will cause the wheel P¹ to be rotated by
reason of its movement over the stationary rack M, whereon movement will be
communicated from the wheel P', through the multiplying gear P2, Q1, Q2, to the
sliding rack G, which will move the traveller G along the range-curve K to permit
the telescope J to be adjusted by the spring J8 at such angles to the tube E that
the line of sight at any instant is directed upon the point at which the fire of the
gun, in its corresponding position, happens to be directed. In other words, the
roller and the range curve co-act to determine the sight angle for each range, so
that when the telescope is directed upon a target in the manner herein before
specified, the requisite elevation will be given to the gun to enable it to hit that
target. A convenient indication of the range is afforded at any moment by the
position of the traveller with regard to the graduated tube E and the graduated
range-curve. Thus, under the conditions specified, the apparatus is a range-finder,
as well as a sight.
With apparatus constructed and arranged in the manner herein before specified,
irregularities in the level of the racers of the platform can be readily corrected in
a manner which will now be explained :-
Transverse inequalities are corrected by means of the cross level J* on the
telescope, which is levelled by rotating the tube E and thereby ensuring the
verticality of the sight.
Longitudinal inequalities are corrected as follows:-The gun is first traversed
to a position where the "racers" have been ascertained to be level, transversely
and longitudinally. This is recorded by attaching a level permanently to the gun
carriage in such a manner that its bubble will be central so long as the racers
remain level at that place.
The range curve is calculated, or is shaped by actual practice in accordance with
the datum height of the gun; consequently the axis of the gun will have, when
the carriage is properly adjusted the correct elevation to hit any one of the targets
on which the telescope can be laid by the elevating screw of the gun, for all positions
of the traveller G on the range curve K.
Next, both the cross level J2 and the longitudinal level J are to be levelled, the
former by turning the bar E, the latter by its own levelling screw J³.
Then the train of gearing P, P2, Q1, Q2 must be locked by turning the handle R¹
and the segmental toothed rack M must be unclamped by suitably operating the
lever O, whereupon the gun should be pointed in the direction and in front of the
target, assuming the latter to be moving across the line of fire.
When the gun is thus pointed, level both the levels, if they have been put out of
level by the unevenness of the racers; the cross level must be levelled by turning
the tube E as before, but the longitudinal level must be levelled by elevating or
depressing the gun by the elevating gear. By this means any quadrantal elevation
lost or gained by the axis of the gun in its transit along the "racers," as shewn by
the disturbance of the bubble of the longitudinal level, will have been compensated
for. After these adjustments, to cause the sight to act automatically re-clamp the

page_text: segmental toothed rack to the gun, and unclamp the train P', P, Q' Q'; then the
cross wires of the telescope are brought on to the target by the elevating gear of
the gun, whereby the proper elevation will have been given to the axis of the
gun to enable it to hit the mark in spite of any previous loss or gain of quadrantal
elevation which may have resulted from irregularities of the racers, as aforesaid.
If the gun is employed against a floating target, the telescope should be laid on
the water line of the target by the elevating gear of the gun, or if the tide be
below the datum level to which the range curve is calculated, the line of sight
should be laid on a point above the water line.
Now level the cross level J2 by turning the tube E, and level the longitudinal
level by its own screw.
The levelling of the longitudinal level at this stage serves to supply the datum
level or level of reference for checking and correcting, if necessary, the quadrant
angle of the gun for the succeeding shot, for the same or any other position of the
gun-carriage on the racers, and it obviates the necessity for re-traversing to the
original datum position on the racers, on each occasion.
I can compensate for the rise and fall of tide in one of three ways, that is to say,
by mechanically increasing the sight angle of elevation given automatically to the
telescope by the movement of the roller along the range curve, raising or lowering,
for this purpose, the cross wires of the telescope up or down a vertical scale therein;
or by supplying different range curves made interchangeable upon the telescope, for
instance in a series on a rotatable collar; or by using only one range curve which
has been calculated for high-water level and by directing the telescope above,
instead of on, the water line of the target for a lower tide, to such an extent as is
taught by the experience of practice.
My improved sight can either be used to act automatically as described above
or by turning the elevating screw of the gun and so moving the roller to zero on
the "
range curve," then clamping the train of gearing in the position it then
assumes, and unclamping the segmental toothed rack from the carriage, it can be
used in conjunction with a graduated arc or spiral, like the ordinary and well-known
"Scott telescopic sight" and can be given by hand the requisite sight or clinometer
elevation for ranges communicated from a range-finder to the gun.
Instead of the stationary rack and the gear hereinbefore referred to, I may
employ a pendulum or other suitable appliance preferably carried by the inbe E,
and becoming operative to move the traveller at a suitable rate along the range-
curve as the gun is elevated or depressed.
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 sighting apparatus comprising a telescope and means consisting of gearing
connected with the telescope and with a stationary rack, or the equivalent of such
gearing and rack, so constructed as to cause the sight to effect, automatically, the
adjustment for range as the gun is elevated or depressed.
2. In a sighting apparatus, the combination with a telescope or its equivalent
hinged to the gun and provided with a range curve, of a bar or tube fixed to the
gun and having a traveller thereon, and means which become operative when the
gun is elevated or depressed and effect, by moving the traveller, the proper adjust-
ment of the angle between the telescope or its equivalent and the bar or tube,
substantially as hereinbefore described, for the purpose specified.
3. In a sighting apparatus of the kind hereinbefore described the combination,
with a bar or tube rotatable about its longitudinal axis in bearings upon the
gun, of a telescope or its equivalent hinged to the bar or tube, and a level
hinged to the telescope, and adjustable in a plane parallel to the axis thereof,
with or without the cross-level, and with or without mechanism for rotating the
bar or tube about its own axis, substantially as hereinbefore described for the
purposes specified.

page_text: 4. In a sighting apparatus of the kind herein before described the combination,
with the hollow bar or tube, of a rack movable therein and provided with a traveller
to operate the hinged telescope or its equivalent, a fixed or adjustable toothed rack
on the mounting, mechanism to gear the rack in the tube with that on the mounting,
with or without clamping-devices for the said mechanism and the rack on the
mounting, and with or without means for taking up back-lash and minimizing the
effect of recoil in the apparatus, substantially as hereinbefore described, for
the purpose specified.
5. In a sighting apparatus of the kind herein before described, springs arranged
and operating substantially as hereinbefore described to prevent back-lash and to
minimise recoil.
6. In a sighting apparatus of the kind herein before described the combination,
with the telescope or its equivalent, of means for adjusting it non-automatically,
relatively to the gun, for the purpose specified.
7. In a sighting apparatus of the kind hereinbefore described, the adjustable
cross-wires, or interchangeable range curves, for the purpose specified.
8. A sighting apparatus, constructed, arranged and operating substantially as
herein before described, for the purpose specified.
Dated this 19th day of Anril 1804
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.