IMPROVEMENTS IN SIGHTING ORDNANCE AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1877

page_text: LETTERS PATENT to Lothian Kerr Scott, Captain in Her Majesty's Royal
Engineers, of the Junior United Service Club, Charles Street, London, in tho
County of Middlesex, for the Invention of "IMPROVEMENTS IN SIGHTING
ORDNANCE AND IN THE APPARATUS EMPLOYED THEREIN."
Sealed the 24th May 1878, and dated the 3rd December 1877.
PROVISIONAL SPECIFICATION left by the said Lothian Kerr Scott at the
Office of the Commissioners of Patents on the 3rd December 1877.
LOTHIAN KERR SCOTT, Captain in Her Majesty's Royal Engineers, of the Junior
United Service Club, Charles Street, London, in the County of Middlesex.
IMPROVEMENTS IN SIGHTING ORDNANCE AND IN THE APPARATUS EMPLOYED
THEREIN."
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This Invention relates to revolving sights for remedying the errors due to the
inclination of the existing service sights when the gun wheels are not on a lovel
platforin, and thereby dispensing with all the calculations at present necessary for
accurate shooting in gunnery practice. These improved sights consist of a foresight
and backsight rigidly connected together by means of a rod of metal or other
material, so that when the backsight is moved into an upright position the foresight
will also move with it into a similar position.
The backsight consists of two parts,—
lat. Of a graduated hinged flap with a slider also graduated for deflection, which
can move along with it and be placed at the proper elevation for firing at any
required range. At the side of the hinged flap is placed a level set at an angle (if
necessary) to allow for the deviation due to rifling; and at the top of the Hap is
a wind gauge, which consists of a bar hung on knife edges, with a small vane at
the top to give a surface for the wind to act upon, and so to deflect it. The
deflections of the wind gauge are read off on a graduated plate, shewing readings
for the different ranges, depending for amount on the force of the wind. These

page_text: deflections are to be given by the firer to his gun to allow for the force of wind
at the time of firing
2ndly. Of a piece of metal to which the flap is hinged, and through which the
bar in connection with the foresight passes and is secured This bar works in two
supports on the gun, one close to the backsight and the other close to the foresight.
On the lower part of the backsight is fixed a nut, through which a screw fixed to
the support by another nut passes. When this screw is turned it makes the whole
system of sights revolve, and therefore can place them in any required position
with the vertical. Instead of moving the system of sights into a vertical position
by this screw the operation can be rendered automatic by using a weight attached
to the backsight, or any part of the system, so as to make a pendulum movement.
These sights can be adjusted vertically by the eye, plumb line, pendulum weight,
or pocket level. The slider is provided with a travelling backsight, which is made
to move by turning a screw which is supported in the sides of the slider. Those
sights can be placed in any convenient part of the gun, and attached in any con-
venient manner.
To use the revolving sights when the wheels of the gun carriage are not on
the level, and the wind is from the right at the range of 3000 yds., without the
employment of calculations, level the system of sights vertically by slow motion
screw, place wind gauge on the top of backsight, and read off the number of
minutes deflection to be given for the force of the wind at 3000 yds. shewn on the
graduated plate of wind gauge, remove wind gauge, aim, and fire. If the shot does
not strike the mark but goes to the right of it, note point of impact, level sights as
before, aim with the same "line of sight" on the object, then move the travelling
pointer of the backsight (by means of the screw which moves it) until the tip of the
pointer, the tip of the foresight, and the point of impact of the shot, are in one and
the same straight line. Now turn the trail of the gun, and aim with this corrected
line of sight, and the shot will strike the mark.

page_text: minutes are made proportional to the times of flight of the projectile at the different
ranges.
The manner in which I use the revolving sight and wind gauge is the following:-
Suppose two guns, sighted on this system, resting on an uneven surface, about to
fire at a mark 3000 yds. distant, with a strong wind blowing from the right, raise
the hinge flap ff, into a vertical position, as shewn in Figs. (1 & 2); move the
slider 8, 8, up to the graduation reading 3000 yds.; place the wind gauge on the
flap f, f, Fig. 3, and read off at 3000 yds. marked on (h, h,) say 5 minutes deflection
due to the force of the wind on (a), remove the gauge, and give 5 minutes right
deflections to the traveller t by turning screw d; level f, f, by screw W, aim at the
mark, and fire a first shot from one of the guns only The pointer of the second
gun will aim at the same mark, and looking over his sights will watch the point of
impact of the shot, and if it fall to the right or left, he will at once turn the screw
d until the notch of the traveller t, the tip of foresight e, and the point of impact are
in line, and this operation will correct the error in direction. In order to hit the
mark he must then aim with this corrected "line of sight" by turning the gun on
to it by means of the elevating screw and trail.
The manner in which I dispense with the calculations for "deflections" which
have to be made for accurate shooting with the service sights is as follows:-The
number of minutes deflections for wind before a shot is fired is given by the wind
gauge.
the
"
The number of minutes deflection for the inclination of the service sights when
gun wheels are not resting on an even platform is entirely eliminated by the
revolving movement given to the plain containing the "line of sight of the re-
volving sight. This movement is the chief point of my Invention, and is one of all
others on which I lay special stress.
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 method of giving the plane containing the "line of sight," of any
description of " sights for ordnance," whether telescopic or otherwise, a revolving
movement about the base of the sights.
2. The method of dispensing by mechanical means (automatically by a weight
attached to the system of sights or otherwise) with all calculations necessary for
the production of accurate shooting with the service sights.
3 The method of being able to place the plane containing the line of sight of
the revolving sight into any given position with the horizon.
4. The method of being able to make the backsight and foresight revolve to-
gether by connecting them rigidly together by a bar of any suitable material.
5. The method generally of making sights to revolve about an axis to eliminate
all calculations in gunnery practice.
In witness whereof, I, the said Lothian Kerr Scott, have hereunto set my
hand and seal, this Twenty-seventh day of May, in the year of our Lord
One thousand eight hundred and seventy-eight.
Witness,
G. A. ANSTEY,
27th May 1878.
103, Harley Street,
London.
L. K. SCOTT, CAPT., R.E. (L.S.)