It is moreover desirable to make the further observation of fire difficult for the hostile artillery, and to diminish the effect of his projectiles at the target (see p. 120 supra) by taking up suitable formations. Broad, shallow formations were suitable against the shell fire of the past. However, they had the great drawback of considerably facilitating the observation of shots falling short or going over, as the smoke from the burst hid the target in the first case, and as the target appeared silhouetted against the smoke from the burst in the second. The cone of dispersion of the modern base charge shrapnel combines comparatively small lateral spread with great effect in depth. The effect of a well-placed shrapnel may be confined to one target, and that of projectiles bursting in the intervals reduced by taking up a formation in which narrow columns (columns of squads) are separated by wide intervals (up to 50 m.). [Illustration] The range is determined or verified by bracketing; that is, by enclosing the target between shots which, fired at a known difference of range, strike respectively, short of and beyond the target. In France this is done either by battery salvo or by piece. In the former case, the French distribute the fire equally over the entire space which they wish to cover with fire; hence, they do not direct it upon the individual columns, especially when they employ indirect laying, their favorite mode of procedure. It is in this kind of fire especially that narrow columns, separated by wide intervals, are a great advantage, because it is pure accident if a projectile falls so that its burst can be observed. Moreover, when the columns are not abreast of each other, the observations of bursts may be contradictory. Thus, in one salvo, “over” and “short” bursts may be obtained, especially if several bursts could not be reliably observed, and the salvo will have to be repeated. When a projectile bursts “short,” immediately in front of the 1st company, for example, it may be assumed that the next projectile will be fired at a range increased by 100-200 m. The 1st company should therefore move to the front at double time, the 2nd and 3rd likewise, while the 4th executes platoons front into line and takes to cover in anticipation of an “over” shot. The “over” meant for the 1st company will then be the signal for the 4th company to rush forward. _The following general rule may be given: A projectile bursting “over” or just “short” of the target requires that the force fired upon move quickly; a projectile bursting far “short” of the target requires that cover be taken._ The platoon and squad leaders of the attacking force should not betray its presence by standing upright; the force should disappear absolutely without leaving a trace. A force cannot, in the long run, prevent artillery from effecting an adjustment of fire upon it; all it can do is to postpone the beginning of the fire for effect. Fire for effect is of three kinds: