Cohesion and order are best maintained, and the least time is lost in action, if efficient, dense firing lines are led forward as units up to the moment of opening fire. (Pars. 169, 321, 334 and 413 German I. D. R.). But on open terrain such dense firing lines would begin to suffer too great a loss at ranges at which they could not reply to the fire. Nothing remains then but to cover the available front with a very thin firing line, followed at irregular distances by thin skirmish lines which ploy for the purpose of utilizing cover or for opening fire. Skirmish lines of this description will hardly justify the opponent’s expenditure of ammunition, as he can only cover broad spaces with volley fire. On the other hand, these skirmish lines are in themselves too weak to facilitate the approach of the following echelons by their fire. Besides, it must not be overlooked that the soldier, separated by a considerable interval from his comrades in line during the advance, and withdrawn from the influence of his officers, succumbs more easily to temporary spells of weakness and is more apt to remain behind than the skirmisher in a dense firing line. The advance in several successive, thin skirmish lines is therefore only an expedient. In each case the leaders will have to decide whether, in view of the close proximity of the enemy, a united advance with dense, powerful skirmish lines is possible or advisable (for instance, when entering at once upon the decisive stage of the action). Before opening fire the firing lines must be sufficiently reinforced. (Par. 334 German I. D. R.). This advance in thin skirmish lines stood the test both in the Boer war and in the Russo-Japanese war,[86] but we must not forget that thin skirmish lines are only maneuver formations in an attack that is to be pushed home, and that the mistake made by the British of attempting to make an attack with such weak skirmish lines should not be imitated. The Japanese also used this formation after they had once opened fire with a dense skirmish line.[87] [86] Four battalions of the 6th Division advanced at Paardeberg on February 18th, 1900, on a front of 2000 m. with 800-1000 rifles, in two lines of equal strength and separated by a distance of 300 m., the remainder following at 400 m. Three battalions of the Highland Brigade even advanced on a front of 4000 m. See my lecture: _Lehren des Burenkrieges_. _Kriegsgeschichtliche Einzelschriften_, 33, pp. 43 and 67. For the Japanese procedure see V. LÜTTWITZ, _Angriffsverfahren der Japaner_, pp. 44 and 66. BRONSART VON SCHELLENDORFF, _Sechs Monate beim japanischen Feldheer_, p. 217.