A blockading army.
An army of observation.
An army of reserve.
A flying army.
The grand army, is that which is the principal of several armies acting at different points remote from each other.
An army is said to cover a place when it lies encamped or in cantonments for the protection of the different passes which lead to a principal object of defence.
An army is said to blockade a place, when, being well provided with heavy ordnance and other warlike means, it is employed to invest a town for the direct and immediate purpose of reducing it by assault or famine.
An Army of observation is so called because by its advanced positions and desultory movements it is constantly employed in watching the enemy.
An Army of reserve may not improperly be called a general depot for effective service. In cases of emergency the whole or detached parts of an army of reserve are generally employed to recover a lost day or to secure a victory. It is likewise sometimes made use of for the double purpose of secretly increasing the number of active forces and rendering the aid necessary according to the exigency of the moment, and of deceiving the enemy with respect to its real strength. Such was the army at Dijon, before Bonaparte entered Italy.
Flying Army, a strong body of horse and foot, commanded for the most part by a lieutenant-general, which is always in motion, both to cover its own garrisons, and to keep the enemy in continual alarm.