Do not stop in a zone under fire for effect as lying down only provides a larger target. If absolutely obliged to stop, remain standing and packed together like sardines, maintaining above formations and intervals. It is useless to run, but, as much as possible, advance steadily. 135.--Protective Formation against all types of shells. As may appear from the study of the above the following formation and intervals will afford the best protection against all types and combinations of types of shells, as a shell will never affect more than one section. Advance in lines of sections in double file, keeping as closed up as possible, with 85 to 110 yards intervals[G] between sections. The second line should be 250 to 300 yards behind the first. FOOTNOTE: [G] All through this chapter, maximum intervals are given. They may have to be shortened to secure closer order at the expense of greater safety. SPECIAL FEATURES OF THE APPROACH. USE OF WOODS AS SHELTER ON THE ADVANCE. 136.--Avoid if small. They should be used to advance or halt only if they are of considerable size. Then, they hide movements and provide some shelter from fire. On the contrary, when they are small, they are to be avoided as they draw artillery fire and do not offer sufficient protection. 137.--Liaison difficult. When advancing in woods, special care should be taken to keep all fractions connected. 138.--Exit quickly at one time. To exit from wood, take all necessary dispositions under cover so that, on the signal of the commander, all fractions may be ready to spring out together. They should continue to advance forward, as rapidly as possible, to avoid the enemy's likely shelling of the outskirts. 138.--Otherwise exit in different places. If the exit cannot be made by all fractions at one time, the elements of the second line should avoid coming out at the same point as those of the first line. TO CROSS A CREST. 139.--Cross altogether and rapidly. Let the line of sections assemble at top of crest, crouching carefully below the sky line. Then, upon concerted signal, all should leap quickly across and down the descending slope, making as extended bounds as possible. This makes crossing fairly safe as even the infantry will have to modify both its elevation and angle of sight for every new position of this quickly moving target. PRECAUTIONS AGAINST CAVALRY. 140.--Cavalry Patrols. During the whole "approach" watch should be kept for possible cavalry patrols. The elements acting as advance guard and flank guards or as combat patrols have as part of their special mission to keep the cavalry away from the main body. 141.--Face and Fire. To repulse cavalry, the infantry must be able to face quickly toward the charging horsemen and furnish a heavy fire. 142.--Protective formations.