The distances permitted between corps of an army upon the march must be governed by the localities, by circumstances, and by the object in view.
NOTE.
When an army moves at a distance from the enemy, the columns may be disposed along the road so as to favor the artillery and baggage. But when it is marching into action, the different corps must be formed in close columns in order of battle. The generals must take care that the heads of the columns, which are to attack together, do not outstep each other, and that in approaching the field of action they preserve the relative intervals required for deployment.
“The marches that are made preparatory to a battle require,” says Frederick, “the greatest precaution.” With this view, he recommends his generals to be particularly on their guard, and to reconnoitre the ground at successive distances, in order to secure the initiative by occupying those positions most calculated to favor an attack. On a retreat, it is the opinion of many generals that an army should concentrate its forces, and march in close columns if it is still strong enough to resume the offensive; for by this means it is easy to form the line when a favorable opportunity presents itself, either for holding the enemy in check or for attacking him if he is not in a situation to accept battle.
Such was Moreau’s retreat after the passage of the Adda by the Austro-Russian army. The French general, after having covered the evacuation of Milan, took up a position between the Po and the Tanaro.
His camp rested upon Alexandria and Valentia, two capital fortresses, and had the advantage of covering the roads to Turin and Savona, by