The tactics of infantry are designed to facili tate, as far as in them lies, that great object of every commander, namely, to make himself stronger than the enemy at the time and place of actual combat, and this can only be done by preserving unity of command, concerted action and mobility, combined with the least exposure of the men to loss. The formations in use at tempt to fulfill these conditions, and the main principles governing in modern infantry tactics are: an individual training and instruction to de velop a high degree of initiative combined with perfect subordi nation; the greatest development of fire in the firing line; a sub division into fire units of such strength as to insure complete fire control by command ers; in the attack, pressure against the flank combined with a frontal attack; the re inforcement of the firing line by a succes sion of lines gradually closing to the front; and, if possible, the accumulation of a greater depth of forces opposite the portions of the enemy where the attack is to be concentrated.
The front line in the attack is composed of the fighting line and its reserve, and the former is subdi vided into the actual firing line and its sup ports. The battalion is the tactical unit and the front it covers, as well as the particular nature of the action, determines the number of companies it places in the fighting line. The battalion covers nor mally about 400 yards of front and a com pany about 100 yards. The progress of the attack will proceed in general outline somewhat as follows: Before entering the zone of artillery fire (or at about 3000 yards) each regiment forms from column of march into line; the bat talions then designate the companies to form the fighting line and those to form the reserve; the companies of the fighting line then designate the sections for the firing line and for the sup ports. The best form of advance of the com panies is in column of sections (half platoons). This line of columns is kept up as long as pos sible, because in this formation the men are under the perfect control of their officers. With in effective infantry fire the column must deploy, since the bullet from the modern firearm can pass through two men at 1500 yards, and at 400 yards it can go through four men. so that the column, if preserved here, must expect heavy losses. In the attack closed columns cannot ap pear in open country within a range of 2100 yards. The successive lines, deployed in open order, or in company column of sections, depend ing on the effect of the enemy's fire, continue to advance. When within effective range, fire is opened, by volleys, or a designated number of rounds at the skirmishers halting to deliver their fire, then advancing again. In open country,
within 1100 yards skirmishers can no longer re main standing. The supports gradually close on the firing line, deploy as skirmishers and begin to re5nforce the firing line. Then begins the advance by rushes, by alternate subdivisions, and por tions of the reserve are added to the firing line, the rest still held in reserve in rear of the point of main attack. The final act is the charge, the reserves being brought up to insure victory and hold the position. The engagement is in general decided at about 900 yards' distance.
This is the general picture, but the details are very various. Long lines of skirmishers can only advance or retire on lines perpendicular to the front, and changes of front are no longer pos sible after the open order is adopted; moreover, throwing out a skirmish line oblique to the front is dangerous, consequently the companies must first be placed on the front to be formed before deploying as skirmishers. The skirmish line, to avoid losses, is often compelled to advance at a run, and systematic rushes are possible only on the drill ground; in the field these rapid advances depend on the local conditions, especially the ef fect of the enemy's fire. The long line, at three or four thousand yards from the enemy, will pass over varied ground, part covered, part open; on the latter artillery fire will make itself felt here and there, and at such points the men will ad vance at a run, then halt under cover, or out of the zone of fire, to await the other parts of the line. These conditions will constantly change in all the different parts of the field.
The infantry attack is decided by fire-action, and to determine the number of skirmishers in the firing line, it must be remembered that there should be at least enough to prevent surprises, and not so many as to interfere with the com mander's freedom of action, in case, for example, it should turn out that a considerable portion of the forces had been placed where they were not really needed. The further development of the fire-action will be determined by the points se lected for decisive action, which cannot usually be determined beforehand.
One of the principal conditions for the success of the attack is that fire once opened should be kept up to about the same strength, and this again indicates the necessity for comparatively weak lines at first ; on the other hand, the enemy should be met with superior forces from the beginning, and this superiority kept up. Be tween these two limits the commander must de cide.