“During the battle of Mukden, on the evening of March 1st, a position at Sha-shan was captured by the Japanese. The Russians had taken up another position some 500 yards in rear, from which they opened an effective fire upon the Japanese infantry in the captured position. Another Russian force about 1,000 yards further to the west threatened their flank. The Japanese, however, succeeded in bringing up _the machine guns which had taken part in the attack, and brought them into action under cover of a number of sandbags abandoned by the Russians_. The effect was decisive: all counter-attacks failed before the annihilating fire of the machine guns.”[26] IN THE DEFENCE When infantry are acting on the defensive, it is advisable that the majority of the machine guns should be held in reserve, and used to check turning movements, to reinforce distant portions of the line of defence, and to deliver counter-attacks, but their principal rôle will be the repelling of the assault. Guns allotted for this purpose must be placed in very carefully selected positions in the line of defence, from which they can command narrow approaches, and sweep ground in front of trenches or important works by cross fire, especially any dead ground likely to afford temporary cover to the attackers. Concealment is of the first importance, and cover from fire absolutely necessary, but the combination of the two requires great skill both in choosing positions and in constructing an inconspicuous shelter. In certain positions where the country is flat or undulating and has no abrupt features, pits will be found the best form of cover; but where the ground presents marked features, emplacements providing overhead cover will not only conceal the guns, but render them immune from shrapnel. The Japanese used these emplacements with great success, the guns often remaining concealed even when the enemy were within 300 yards.