In making these arrangements, it is of the utmost importance to secure the artillery of the main position against the fire of the enemy's advanced skirmishers or marksmen; and with this view, the batteries ought to be covered in their immediate front by a line of extended riflemen, placed either in trenches or pits or behind natural cover, at a distance of from four to five hundred yards in advance of the guns which they defend. If the battery is on a flank, this protection should also be extended for a similar distance to the flank. The infan try thus posted would remain as long as possi ble in position, and only retire when, at the final stage, they are driven back by the over whelming advance of the assailants. Besides their principal function, of keep-off the enemy's skirmishers from too early approach to the batteries of the defense, these advanced infantry could often bring an irritating fire to bear upon the attacking artillery at its first principal posi tion, and perhaps serve to prevent the guns from approaching to the most telling ranges. This possible action would of course depend much upon the features of the ground.
It is impossible to lay down any rule for the exact position of the artillery of reserve. High ground near the exposed flank, provided facility of movement therefrom in case of necessity is presented by its features, would often be suitable. The guns should, however, in any case be well up to the front, so as to lose no advantage of range from the commence ment of their fire. A position in rear which entails not only a sacrifice of some hundreds of yards range, but the necessity of firing over the heads of the defending infantry, greatly to their discomfort and demoralization, does not appear to present commensurate advantages of safety to the guns. It is evident that artillery so placed would be comparatively useless dur ing the later stages of the defense, when once the attacking infantry has advanced so dose that the fire of the retired batteries would be masked by the ground, or by the defending infantry lining the position. Guns so placed might be useful in defending an inner line, or for supporting a counter-strolce delivered inside the position after the assault has been made, but their action would be lost almost altogether during the period immediately preceding the final attack of the position. The previous knowledge of ranges and distances, possible to the artillery of the defense, presents a great advantage; but if circumstances have not per mitted the gunners to ascertain them during the preliminary arrangements, by aid of range finders, aeroplanes, or ether means, the earliest portion of the artillery action must be utilized to obtain correct estimates of the ranges to all important points, by means of trial shots.
There are certain points or portions of all positions, the possession of which would assure the assailant the greatest tactical advantages. In many cases also the conformation of the ground appears to limit the movements of an enemy to certain lines of operation. The de fense should, therefore, occupy these parts of the position in force, with supports in close proximity, while still preserving the general line. Under the second condition the force should be prepared to resist advance by rapid re-en forcements at any of the possible points of approach. The reserves of the third line should be placed so as to be available for strengthen ing the most likely points of attack and to be able to protect the line of retreat. Most of the cavalry, and some horse-artillery if it can be spared, would be placed with the reserves. Sometimes a portion of this force is placed in the second line for the purpose of joining in forward movements and flank attacks upon the assailants, or of covering the retreat of the troops engaged in these counter-attacks if un successful.
The second stage generally commences with the opening of fire at long range from the main batteries of the position, upon the heads of the enemy's infantry to quit its order of march and deploy. The attacking artillery will probably now reply from its first principal posi tion, and as the artillery of the attack is at this time the most important arm it must be answered by the guns of the defense. In this artillery duel the defenders should have the advantage, as knowing accurately the ranges to the various points which must be occupied by the enemy in his advance, and as being more over entrenched while the assailants are all comparatively exposed. During the second stage the infantry of the defense are brought up into position and open long-range fire upon the advancing enemy with more or less effect.
In the third stage the advance to effective rifle range of the attacking infantry has forced the defense to show more clearly the positions for the real attack, the direction of which it is now the object of the defending commander to discover, by every means in his power. As the supports and reserves of the assailing in fantry come clearly into view, they should receive the concentrated fire of part of the artillery of the defense.