13. Why may the point-blank be considered constant for the same calibre?
The dimensions, charges, and weights of projectiles, being constant, and the inclination of the natural line of sight, except in a very few cases, being comprised between 0° and 15°, it follows that for the same calibre, the point-blank may be considered constant, and may serve as a point of reference in firing at different distances.
14. What is the extreme range of a piece of artillery?
The distance from the piece to where the projectile finally rests.
15. For a given velocity what effect has an increase of the angle of lire on the range?
It increases with the angle of fire up to a certain limit, beyond which it diminishes.
16. What angle gives the greatest range in vacuo?
Forty-five degrees.
17. When will this angle give the maximum range in practice?
Only for feeble charges, and very heavy projectiles.