CHAPTER II.
EXAMINATION OF FIRST-CLASS GUNNERS.
(a) THE AZIMUTH INSTRUMENT AND DEFINITIONS.
Q. What is an angle?
A. An angle is the divergence of two intersecting lines.
Fig. 57.
In Fig. 57 the two intersecting lines SA and XA form the angle SAX, and when measured on the circle with A as the center it is found to be equal to 80°.45 (eighty and forty-five hundredths degrees).