The infantry can not open fire until within rifle range of the enemy and should try to get much closer before doing so. In open country, however, infantry may be subjected to artillery fire while crossing the ground from 5000 yards to, say 1200 yards from the hostile position, with no chance to reply. The problem to be solved by the infantry commander is how to cross this zone without losing too many men and too much time. [Sidenote: In skirmish line] In skirmish line. The long advance in this formation is tedious work, and the target offered is sufficiently vulnerable to draw artillery fire. If no cover is afforded in the terrain the line is apt to suffer heavy loss and become more or less disorganized before reaching the point where it will take up the fire fight. Where the line of advance is crossed by ridges, sunken roads and other features of that kind affording cover, where the line can rest and to a certain extent reform, this formation can be used to advantage, especially if the terrain permits us to approach under cover from artillery fire to within two or three thousand yards. If this formation be used in a force of some size, as a war strength battalion or more, the platoons should not keep on a line but in an irregular echelon formation. [Illustration: —— —— —— —— —— —— —— —— —— This makes a much more difficult target for the artillery. The distance from front to rear between any two adjoining platoons should not be less than 150 yards. The advance in skirmish line has the advantage of being in the formation that it will be necessary to have when you open fire and no changes are necessary and, if the enemy is encountered much sooner than expected, you are prepared. [Sidenote: The squad column] The squad column. This formation was devised by our soldiers at maneuvers at Sparta and in California, where the ground in part was covered with thick brush. It was found an excellent formation to take when the skirmish line encountered these patches of thick brush. Since it was placed in the I. D. R. it has been understood by some as a good formation for advancing in the _open_ against artillery fire. This is a mistake. It should never be so used. In this formation there will always be two squads, and generally three, in the burst of a single shrapnel, exposing more men to danger than if they were in skirmish line.