The normal use of Corps of Position is limited to Lines of Mobilization, of Development and to the Simple Line of Manoeuvre. CORPS D’ARMEE OF EVOLUTION. _“Every man in Alexander’s army is so well trained and obedient that at a single word of command, officers and soldiers make any movement and execute any evolution in the art of warfare._ _“Only such troops as themselves can check their career and oppose their bravery and expertness.”--Caridemus._ _The eight Pieces_, by reason of their ability to move in all directions, the scope of their movements and the peculiar exercises of their offensive and defensive powers, are best adapted of the Chesspieces to perform those functions which in the Military Art appertain to Corps of Evolution. _Corps of Evolution_ acting offensively, take their individual appelations from the points which constitute their objective in the true Strategetic Horizon, viz.: 1. Corps of the Right. 2. Corps of the Centre. 3. Corps of the Left. _Corps of Evolution_ acting defensively, take their individual appelations from the particular duties they are required to perform, viz.: 1. Supporting Corps. 2. Covering Corps. 3. Sustaining Corps. 4. Corps of Impenetrability. 5. Corps of Resistance. The normal use of Corps of Evolution is limited to Lines of Manoeuvre. When acting on a Simple Line of Manoeuvre, a Corps of Evolution may deploy on the corresponding Line of Mobilization; but it has nothing in common with the Line of Development, which latter appertains exclusively to Corps of Position. Any corps d’armee, whether of Position or of Evolution may be utilized upon a Line of Operations. THE KING. Regarded as a Chessic Corps d’armee, the King marches as infantry, cavalry and artillery; but it attacks as infantry exclusively and never as cavalry or artillery. Although every situation upon the Chessboard contemplates the presence of both Kings, either, or neither, or both, may, or may not be present in any given Strategetic Horizon. Whenever the King is present in a given Strategetic Horizon the effect of his co-operation is mathematically outlined, thus: I. At his maximum of efficiency, the King occupies the centre of a circle of one point radius. His offensive power is equally valid against all eight points contained in his circumference, but his defensive power is valid for the support from a minimum of one point to a maximum of five points. II. At his medium of efficiency the King occupies the centre of a semi-circle of one point radius. His offensive power is valid against all five points contained in his semi-circumference, and his defensive power is valid for the support from a minimum of one, to a maximum of five points. III. At his minimum of efficiency, the King occupies the centre of a quadrant of one point radius. Both his offensive and his defensive powers are valid against all three points contained in his segment. THE QUEEN.