The elevated ground which constitutes the position should be able to contain all the troops who are to occupy it ; but it should not much exceed the extent necessary for thii purpose, lest, not being able to defend the whole, the army should be deprived of the advantages arising from a superiority of command, in consequence of the enemy gaining some part of the height.
However favourable a position may be with respect to the elevation of the ground, that circumstance will be of small value if the troops and artillery cannot be conveniently placed on it. It is indispensable that the ground afford ample room for the manoeuvres of that species of troops in which the strength of the army chiefly lies; and at the same time it may be observed that, in making choice of a position, the ground In front should be as much as possible disadvantageous in that respect for the enemy. The Spanish general, Cuesta, is blamed for having, previously to the battle of Rio Seco, in 1808, placed his army in such a situation that the ground before it was in the highest favourable for the action of the French cavalry, which was numerous. Artillery should always be laced where it can act with most effect ; and when the ground occupied by an army presents alter nately salient and retired points along the front of the line, the bat teries should be placed at all such points. At the former, in order that the lines of fire may effectually command the approaches by which the enemy's columns may advance ; and at the latter, that they may defend the descending ground immediately in front of the others. Infantry may occupy any kind of ground, but should, if possible, always form a close line. It is usually placed between the batteries ; and, if exposed to a distant cannonade, the troops may be drawn up in a trench. the earth from which will serve to cover them, without pre. venting them from marching out in line to meet the enemy. Cavalry must be posted on a level plain, over which it may advance with regu larity when a charge is to be made ; if compelled to act on broken ground, it is formed in small detachments behind the infantry, through whose intervals it may pass at proper opportunities. It may be observed, that every disposition of an army for defence should correspond to that of the works which constitute a fortified place. The batteries at the advanced points of the line serve a purpose similar to that of the guns in the flanks of bastions ; and the intermediate line of troops forms a sort of curtain.
In the choice of positions for offensive operations, such should be taken as have no rivers or broken ground in front since these would impede the contemplated movements towards the enemy : small inequalities, behind which infantry or cavalry may be concealed, are, however, advantageous, as they afford the means of occasionally making attacks by surprise. On the other hand, when an army is on the defensive, the front as well as the wings should be protected by every obstacle to the progress of the enemy which nature may present or art can devise ; among those afforded by the latter may be meutioned the blocking up of roads by abatis or traverses ; preparing countermines by which, on the enemy's advance, the roads may be destroyed; rendering fords impassable and eveu forming inundations by construct ing dams across the streams. It should be observed, however, that when a defensive position is covered by a river, the line of troops should be at 800 or 1000 yards in rear of the latter, in order that sufficient space may be afforded for the troops to act against the enemy iu the event of his forcing a passage across ; and, in all cases, every obstacle in the way of a free communication within the position ought to be removed, that the troops may easily succour each other when attacked. Whatever be the nature of the obstacles opposed to the enemy, they should be within the range of the artillery of the 1Me ; and then the position may be considered as impregnable, since an enemy would find it scarcely possible either to form or deploy his columns of attack on broken ground and under a destructive cannonade. Good roads, ou the other hand, should exist, or should be formed, in the rear, both to facilitate the arrival of supplies from the magazines or depths, and to favour a retreat, should the latter step become neces sary. An arrrly always retires in disorder under the fire of the enemy, and its danger is greatly iucreased when the retrograde movement is embarrassed by walls, ravines, streams, or other impediments ; the divisions then become separated from each other, and some of them are generally cut off by the enemy before they can be supported. It would be advantageous that the ground in rear should command that of the position itself ; for then the army, in retreating, would obtain a superiority of elevation over the pursuing enemy; and it might even have an opportunity of renewing the action with a prospect of success.