As regards the offensive, it enjoys to a certain extent the same advantages as the defensive from the more elevated ground; for this reason that the stragetic attack is not confined to one act like the tactical. The strategic advance is not the continuous movement of a piece of wheelwork; it is made in single marches with a longer or shorter interval between them, and at each halting point the assailant is just as much acting on the defensive as his adversary. Through the advantage of a better view of the surrounding country, an elevated position confers, in a certain measure, on the offensive as well as the defensive, a power of action which we must not omit to notice; it is the facility of operating with separate masses. For each portion of a force separately derives the same advantages which the whole derives from this more elevated position; by this—a separate corps, let it be strong or weak in numbers, is stronger than it would otherwise be, and we can venture to take up a position with less danger than we could if it had not that particular property of being on an elevation. The advantages which are to be derived from such separate bodies of troops is a subject for another place. If the possession of more elevated ground is combined with other geographical advantages which are in our favour, if the enemy finds himself cramped in his movements from other causes, as, for instance, by the proximity of a large river, such disadvantages of his position may prove quite decisive, and he may feel that he cannot too soon relieve himself from such a position. No army can maintain itself in the valley of a great river if it is not in possession of the heights on each side by which the valley is formed.