NOTE.
It was the opinion of Frederick that an advanced guard should be composed of detachments of troops of all arms. The commander should possess skill in the choice of ground, and he should take care to be instantly informed, by means of numerous patrols, of everything passing in the enemy’s camp.
In war, it is not the business of an advanced guard to fight, but to observe the enemy, in order to cover the movements of the army. When in pursuit, the advanced guard should charge with vigor, and cut off the baggage and insulated corps of the retiring enemy. For this purpose, it should be reinforced with all the disposable light cavalry of the army.
MAXIM XXXIII.
It is contrary to the usages of war to allow parks or batteries of artillery to enter a defile, unless you hold the other extremity. In case of retreat, the guns will embarrass your movements and be lost. They should be left in position, under a sufficient escort, until you are master of the opening.