Several objects are served by these manoeuvres. In the first place, the separate exercise of brigades preceding the manoeuvres proper completes the formal training of the troops, and gives practice in the evolutions of large homogeneous masses of each of the three arms. The manoeuvres of divisions and army corps serve to accustom the three arms to act in concert, and to overcome the great friction which at first always impedes the movements of such large composite bodies. All the various manoeuvres, moreover, give the superior officers the opportunity of inspecting the work of their inferiors, that is, of ascertaining how far the training of the troops has been thorough, and with what degree of skill they are handled. Not the least important purpose of the manoeuvres is the training of commanders. The troops are divided into two parties supposed to be enemies at some stage of an imaginary war. The commander of each side learns from the umpire the nature of the supposed operations which have brought his forces into their actual situation, together with such information concerning the enemy as in real war he might be presumed to have obtained. He has then to act according to his own judgment. In this way the generals are practised and tested in the power of rapidly and surely grasping situations such as occur in war and of acting upon the insight thus gained. The arrangements are so made as to afford practice like this to as many officers as possible of all ranks, though it is chiefly the generals, the commanders of brigades, divisions, and army corps who profit by them. Thus the Prussian system of training produces as the net result on the one hand an army corps as an instrument pliable to its commander's touch, so that it can be surely and easily handled in any situation, and on the other hand a general skilled in the manipulation of this powerful and complicated instrument. [1] _Felddienstordnung_, §§ 1, 2. CHAPTER IV THE ARMY CORPS