.

300 to 500 " Even at these distances the aim is usually so inaccurate that a large portion of the projectiles are lost.

In the attack on Spires, a whole column of artillery expended its fire while at a distance of 900 yards from the enemy, who, of course, received little or no injury.

In firing from fortifications, the aim is far more accurate, and the artillery may therefore be employed to advantage as soon as the enemy comes within the longest range.
II.

As an arm of succor, the artillery serves, 1st, to give impulsive force to the attacking columns; 2d, to assist in arresting, or at least in retarding, the offensive movements of an enemy; 3d, to protect the avenues of approach, and to defend obstacles that cover a position; and, 4th, to cover a retrograde movement.
Mounted artillery is, like cavalry, much the most effective in attack; but batteries of foot are better calculated for defence.