A. It is a horizontal angle measured from zero degrees at the south in a clockwise direction.
Q. What is meant by a horizontal angle?
A. One whose intersecting lines or sides are parallel with the level of water at that point.
Q. What is a vertical angle?
A. One whose sides lie in a plane of a plummet.
Q. Can an azimuth angle be greater than 90°?
A. Yes. See Fig. 51. SAT = azimuth of target (less than 90°); SAT' = azimuth of target (greater than 90°, but less than 180°); SAT'' = azimuth of target (greater than 270°). (All these azimuth angles are read in a clockwise direction from zero at the south.)
Q. When is a gun or an instrument said to be set in azimuth?
A. When it reads zero and points south.
Q. What is an azimuth-instrument?