1. In approaching the enemy through a wooded or broken country, skirmishers thrown out in advance, and on the flanks of the leading column, are absolutely indispensable, in order to reconnoitre the ground, and prevent a surprise.
2. Skirmishers protect the main body, or any particular portion of it, from attack while manœuvring.
A regiment, or a brigade, in covered ground, whether the enemy be visible or not, should never change its position in battle, or manœuvre, without the protection of a skirmishing line.
3. They furnish a screen, behind which the main body may hide its movements, and be enabled to attack at an unexpected point.
4. Where a ravine, a wood, or other similar obstacle causes a break in our line of battle, by occupying it with skirmishers we guard it against penetration by the enemy, and connect the separated corps with each other.
5. Skirmishers may be used to alarm the enemy at a point where he expected no attack, and thus create a diversion.
6. By their attack at various points, they serve to unmask the enemy's position.
7. They may be employed to open the way for a charge with the bayonet.
At the battle of Stone River, the rebels, on one occasion, advanced in line, with a double column in rear of each wing, preceded by a double line of skirmishers, who reserved their fire till close to our line, when they halted, poured in a murderous fire, and fell back on their main body, which then rushed forward. Both our first and second lines, staggered by this sudden and destructive fire, were swept from the ground.
8. Skirmishers have been sometimes thrown forward to test the spirit and disposition of the enemy.