From the moment an army approaches the enemy, it should march in the order in which it is intended to fight. If anything is to be apprehended, precautions are necessary in proportion to the degree of the danger. When a defile is to be passed, the troops should be halted beyond the extremity, until the whole army has quitted the defile.
In order to conceal the movements of an army, it is necessary to march by night through woods and valleys, by the most retired roads, and out of reach of all inhabited places. No fires should be allowed; and, to favor the design still more, the troops should move by verbal order.
When the object of the march is to carry a post, or to relieve a place that is besieged, the advanced guard should march within musket shot of the main body, because then you are prepared for an immediate attack, and ready to overthrow all before you.
When a march is made to force a pass guarded by the enemy, it is desirable to make a feint upon one point, while, by a rapid movement, you bring your real attack to bear upon another.
Sometimes success is obtained by pretending to fall back upon the original line of march, and, by a sudden countermarch, seizing upon the pass, before the enemy is able to reoccupy it.
Some generals have gained their point by manœuvring so as to deceive the enemy, while a detachment under the cover of high grounds has surprised the passage by a stolen march.
The enemy being engaged in watching the movements of the main body, the detachment has an opportunity of entrenching itself in its new position.