Definitions
from The Century Dictionary.
- noun A bar of metal forming part of the breech-sight of a cannon, having the range marked on it in yards or degrees.
Etymologies
Sorry, no etymologies found.
Support
Help support Wordnik (and make this page ad-free) by adopting the word sight-bar.
Examples
-
If then the bottom of the sight-notch coincides with the bottom of the bar, the line of sight is parallel to the axis; otherwise, the reinforce-sight or the sight-bar must be lowered until coincidence is obtained.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
The upper edge of the sight-bar corresponds with 0° when the line of sight is parallel to the axis of the bore.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
But, with the sight-bar at level, if a gun is aimed by it at the water-line of a vessel at point-blank range, the shot would strike short of the point aimed at by about one-quarter of the distance; or, if aimed, under similar conditions, at the upper part of the hull, the shot would fall a distance below the point aimed at equal to the height of the gun.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
Various modes have been practised to ascertain at sea the distance from the object aimed at, so as to regulate the elevation of guns, but none can be depended upon for giving it with minute accuracy, and even when obtained it is continually varying; therefore, when the projectile is seen to exceed or fall short of the object considerably, the sight-bar must be readjusted accordingly.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
The outer end of this bar is placed on the reinforce-sight, which has been previously adjusted to the proper height, and the bevelled end in contact with the outer face of the sight-bar.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
The support for the sight is then to be fitted to the breech, at the distance from this line marked on the pattern-sight for its calibre, with the bottom of the sight-notch in the bar, exactly the height of the front sight (one inch) above the upper surface of the rimbase; the sight-bar perpendicular.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
A centre line on the bar verifies the coincidence of the line of sight, and also the motion of the sight-bar in the vertical plane.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
In fitting new guns, or those upon which the sights require replacing, the sight-bar will be fitted as described in Article 289, and graduated from 100 yards downwards.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
No. 1 removes sight-bar and screws up the thumb-screw firmly.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
-
For shot-guns the ranges in yards for one shot with the distant-firing charge of powder are marked for each degree of elevation on the right in-board face of the sight-bar; for the ordinary firing, on the left face.
Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance
Comments
Log in or sign up to get involved in the conversation. It's quick and easy.