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

page_text: LETTERS PATENT to Lothian Kerr Scott, Captain in H.M. Royal Engineers,
of the Junior United Service Club, Charles Street, St. James's, in the County
of Middlesex, for the Invention of "IMPROVEMENTS IN SIGHTING ORDNANCE
AND IN THE APPARATUS EMPLOYED THEREIN."
Sealed the 29th June 1877, and dated the 3rd January 1877.
PROVISIONAL SPECIFICATION left by the said Lothian Kerr Scott at the
Office of the Commissioners of Patents on the 3rd January 1877.
"
LOTHIAN KERR SCOTT, Captain in H.M. Royal Engineers, of the Junior United
Service Club, Charles Street, Saint James's, in the County of Middlesex. IMPROVE-
MENTS IN SIGHTING ORDNANCE AND IN THE APPARATUS EMPLOYED THEREIN:"
These improvements are mechanical improvements for the manipulation of my
improved "sights," designated the “ Scott-pendulo-telescopic-micrometric sight,"
already Invented and Patented by me, and numbered 3964, November 18, 1874,
which gives rise to a new system of sighting guns and enables the firer to have
complete command over the axis of the piece under all conditions without the
necessity for making any calculations, and which can also be applied for range
finding.
This improved instrument I designate as "Scott's Improved Telescopic Sight,"
and consists of two parts, the bracket and "sight." The bracket is fixed to any
convenient part of the gun, and has two bearings cut in it as nearly as possible
parallel to the axis of the gun, which are to receive the "axis of revolution" of the
sight. To the bracket is secured a spring to assist in levelling the sight.
The "sight" consists of an ordinary telescope with "cross wires" which may be
of any suitable material or be represented by marks on glass, and is moved in a
vertical direction by means of a slow motion micrometer-headed screw, which is
attached to an arm fixed to the trunnion of a telescope, graduated as a vernier to read
off to degrees and minutes the divisions on the vertical arc, which acts at the same
time as one of the two supports to the telescope. These two supports are fixed to a
square collar which also has an arm acting as a vernier to read off to degrees and
minutes the divisions graduated on the body of the axis of revolution, and the
telescope, supports, and collar together fitting on to the vertical spindle of the axis

page_text: of revolution allow of a horizontal movement being given to the telescope by a
slow-motion micrometer-headed screw. At the side of the body of axis of revolu-
tion is fitted a screw with a ball which slips into a cup underneath the bracket and
is used to level the instrument by means of a spirit level fixed at right angles to
the arm of the collar which moves with it.
.
I will now proceed to give an instance of the method of sighting the apparatus
for the purpose of this Invention. Suppose the gun is to be fired with an elevation
of 20° 19', one wheel lower than the other and the "wind" from the right. Turn the
slow-motion screw which works the arm of the vertical arc until the telescope be
depressed through an angle of 20° 19′, and turn the slow-motion screw which gives
the telescope a horizontal movement until the amount of deflection required for
"wind" and "rifling" be given. Place the "sight" into its bearings on the bracket
which is fixed to the gun, and if the wheels be on uneven ground, level the "sight"
by the slow-motion screw for that purpose, lay the cross wires on the object, lift
the "sight" off the bracket, and fire.
To find the Range. To find the range a tripod must be provided which has
circular graduated plates with bearings similar to those on the bracket for the
reception of the "sight," so that horizontal angles may be observed in the ordinary
way from the ends of a base line and the range therefrom acquired by reference to
previously calculated tables.
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 3rd July
1877.
LOTHIAN KERR SCOTT, Captain in Her Majesty's Royal Engineers, Junior United
Service Club, Charles Street, Saint James's, in the County of Middlesex. "IMPROVE-
MENTS IN SIGHTING ORDNANCE, AND IN THE APPARATUS EMPLOYED THEREIN."
My Invention, which I designate as Scott's Telescopic Sight, relates to im-
provements in sighting ordnance and in the apparatus employed therein, and its
object is to dispense with the calculated deflections necessary for accurate shooting
with the present service sights (consistent of a tangent sight and fore sight) when
the gun wheels are not on the level by means of mechanical adjustments, and also
to give the firer the power of seeing and taking aim at objects with greater accuracy
at distances equal to the range of the gun by means of the line of collimation of a
telescope.
The said improvements may be applied to any ordnance. The manner in which
I carry the said Invention into practice is illustrated in the accompanying Drawing,
in which,
-
Fig. 1 is the side elevation of the Scott telescopic sight and bracket.
Fig. 2 is the plan of the bracket and of the tray of the axis of revolution, also
the plan of the collar and arm with vernier.
Fig. 3 is the side elevation of the axis of revolution.
Fig. 4 is the end.elevation of the sight and bracket, leaving out the micrometer-
head screws of the of the vertical and horizontal arcs.
Like letters indicate the same parts throughout the Drawing.
The "sight" consists of a telescope (t) with "cross hairs" (of any suitable inaterial,
or they may be represented by lines on any transparent substance); its two supports
(a, a,) one of which is used as the vertical arc and is graduated to degrees which
are read to minutes by means of a vernier b, Fig. 1. This vernier may be made on
the arm b which is fixed to the trunnion of the telescope, or the arm (b) may be dis-
pensed with altogether and in its stead a collar may be fitted on the telescope with
a vernier like a claw coming round the edge of the vertical arc and fitting into the

page_text: groove cut in the vertical arc (a) for its reception. The slow-motion micrometer-
headed screw (c) passing through two nuts, one fitted to the vertical are, the other, to
the vernier (6), is to move the telescope (t) through the various angles of elevation
required for the different ranges of the gun. The two supports (a, a,) are secured
to the collar (m, m,) which has an arm (h) graduated as a vernier (v) to read to
minutes the degrees graduated on the tray (k), Fig. 2, of the axis of revolution g.
This collar fitting very accurately, the vertical axis (m¹) of the axis of revolution is
kept down in its place by the end of the vernier (v) sliding into a groove cut in the
tray of the axis of revolution, and by a washer which is secured to the top of the
vertical axis by a screw sufficiently loose to allow of the telescope, supports, and
collar (m, m,) together, having a horizontal movement of as many degrees as may be
required. This horizontal movement is given by the slow-motion micrometer-
headed screw (e), and is to enable the firer to turn the telescope (t) on to the point of
impact of the shot when he wishes to correct his " line of sight" and to give required
deflection to axis of gun for wind or other causes. The tray (k) of the axis of
revolution has two projections (p and q), one is a flat piece of metal on which the
spring (8, 8,) which is screwed to the bracket presses when the "sight" is in the
grooves of the bracket with the levelling screw (f) in its receptacle on the under
side of the bracket (n, n,) the other (9) holds the nut and screw (f), which has a cup at
its point to work in the recess cut on the under side of the bracket for its reception
when the axis of revolution is in the grooves of the bracket with its projection
under the flat spring (8, s). This screw is to turn the vertical arc into a vertical
position when the gun wheels are not on the level, which position is ascertained by
the level (d) which is fixed to the arm (h) of the collar (m) at right angles to the "line
of collimation of the telescope." The bracket (n, n,) may be a piece of metal of any
shape or size, with two grooves bored in it parallel or at the mean angle of deviation
for "rifling" to the axis of the gun; on one side is the recess in which the cup. of (f)
fits, on the other side is the flat spring (s, s,) which presses the axis of revolution into
its bearings when the cup of (f) has been slipped into its position under the bracket.
To use the Sight.- Depress the telescope (t) by turning the screw (c) until the arm
(b) has been moved through the angle of elevation required. If there be wind, move
the telescope (t) horizontally by screw (e) until the amount of deflection for the force
of the wind has been given, which is regulated by the scale on the tray of the axis of
revolution (g, g,) or by the micrometer head of (e); place the "sight" on the bracket
(which may be attached to any convenient part of the gun, provided the center
line of the grooves be parallel or nearly so to the axis of the gun; focus the "cross
hairs" and direct them on the object by raising or lowering the elevating screw of
the gun and by shifting the trail, level the "sight" by turning screw (f) till the
bubble of the level (d) be in the centre, then see that the "cross hairs" be still on
the object; if not, direct them as above explained again on the mark, lift the "sight"
off, and fire.
To place the "sight" on the bracket, I place the projection (p) under the flat
spring (8, 8,) and allow the axis of revolution (g, g,) to fall into the grooves of the
bracket (n), then I press the head of the screw (f) towards the support (a, a,) of the
telescope until the cup is clear of the projection (q, q,) of the bracket, and down-
wards till the cup can rise by the force of the spring (8, 8,) into the recess for its
reception.
The manner in which the Scott telescopic sight dispenses with the calculations
for deflection which have to be made for accurate shooting with the service sights
is the following:-
"
The force of wind and "ridling" excepted, ordnance cannot fire with accuracy
unless the "sights are vertical. When the wheels are on uneven ground, the
"sights" are inclined, and therefore if the gun were fired in this position the shot
would go on that side of the mark to which the "sights" are inclined. To obviate
this error in shooting, it is necessary to place the sights upright, or in other
words, to place the gun wheels on the level. As this is not done, calculations
have to be made to allow for this deflection of the shot, the result of which calcu-

page_text: lations have to be applied to the "sights." Instead of making these calculations, I'
always turn the sight into an upright position by means of the screw (f) which at
once dispenses with the necessity for the above-mentioned calculations. This then
is one of the chief points of my Invention, and one 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 utilizing for ordnance the "line of collimation of a telescope
with "cross hairs" as the "line of sight," instead of taking the "line of sight" in the
ordinary way by means of a back sight and fore sight, thereby dispensing with
these sights.
2. The method of being able to place the plane containing the "line of sight" of
the Scott télescopic sight in a vertical position when the gun wheels are not on the
level by making the sight capable of revolution.
3. The method of placing the axis of revolution of the sight into the grooves of
the bracket and of securing it in its place by means of a spring which presses it
down to the centre of its bearings when the cup of the levelling screw is in its
receptacle.
•
4. The method of making sights to revolve about an axis to eliminate all calcula-
tion in gunnery practice.
5. The method of giving deflection to the sight by the horizontal movement of
the telescope.
In witness whereof, I, the said Lothian Kerr Scott, have hereunto set my.
hand and seal, this Third day of July, in the year of our Lord One thousand
eight hundred and seventy-seven
Witness,
W. ANSTEY, Lt.,
71st H.L.T.
L. K. SCOTT, CAPT., R.E. (L.S.)