When an immediate decision is not sought, it is advisable to increase distances in order to keep the echelons held back in rear from coming under fire. In any case, the distance between supports and firing line should be less than the distance between firing line and enemy. In an attack, supports should be close enough to the firing line to prevent, by timely interference, a retrograde movement of the latter. On the defensive, on account of the difficulty of bringing up supports for the purpose of repulsing an assault, they will usually be placed a short distance immediately in rear of or within the firing line (intrenched) at the points where they are to be employed. During an attack, whenever the lines in rear cannot be kept out of hostile fire, care must nevertheless be taken that two echelons be not simultaneously struck by a cone of infantry fire or by one and the same shrapnel. The distance between echelons is therefore increased to more than 300 m., and should not be reduced until the decisive stage of the combat approaches. In open country, supports held too close to the firing line will soon cease to exist as such. When kept in close order, their losses would be so great that the boldest men would join the firing line and the less courageous would hunt cover. Everything depends upon the manner in which supports are led forward, especially during that part of the advance immediately preceding their junction with the firing line. In this lies the whole art of fighting in deep formations. Covered terrain permits distances to be reduced. The commander should be particularly careful not to let this advantage escape him, since on such terrain it is more frequently necessary promptly to reinforce the firing line. The commander of the support must constantly observe the movements and successes of the firing line in order that he may be able to reinforce it in the most advantageous manner. Whenever he is obliged to split up his command during a movement to the front, he should endeavor to reunite it at the first opportunity. The support should closely adapt its movements to those of the firing line. When a part of the firing line makes a rush, the support halts for the moment, and then runs forward to the next cover, simultaneously with the next advancing unit of the firing line, and covered by the fire of the skirmishers in front. “To make a rush at the same time as the firing line was impossible, because, as soon as the latter rose, the Turks opened a murderous fire. Whenever the firing line threw itself down and returned the fire, that of the enemy became noticeably weaker.”[101] [101] _Report of Lieutenant Borsov_, in KUROPATKIN-KRAHMER, _Kritische Rückblicke auf den Russisch-Türkischen Krieg_, III, p. 183.