Meanwhile, beyond these great mountain ranges, are advancing to the aid of the combatants, two other armies, represented by the power of promotion possessed by the Pawns. Each of these two hypothetical armies is assailing the outer slope of that range of mountains which lies in the rear of the hostile force. Its effort is to pass one of the eight defiles and by occupying a Point of Junction in the kindred Logistic Horizon, to gain entrance into the Topographical Zone. Then in the array of a Queen, or some other kindred piece, it purposes to attack decisively, the adverse Strategetic Rear. To oppose the attack of this hypothetical hostile army, whose movements always are typified by the advance of the adverse Pawns, is the duty of the kindred column of manoeuvre. Primarily this labor falls upon the kindred Pawns. Upon each Pawn devolves the duty of guarding that defile situated directly on its front, by maintaining itself as a Point of Impenetrability between the corresponding hostile pawn and the kindred Strategic Rear. Conversely, a second duty devolves upon each Pawn; and as an integer of the Column of Support, it continually must threaten and whenever opportunity is presented it decisively must assault the defile on its front, for the purpose of penetrating to the kindred logistic horizon and becoming promoted to such kindred piece, as by attacking the adverse Determinate Force in flank, in rear, or in both, may decide the victory in favor of the kindred army. Every variety of topography has peculiar requirements for its attack and its defence; and situations even though but little different from each other, nevertheless must be treated according to their particular nature. In order to acquire the habit of selecting at a glance the correct posts for an army and of making proper dispositions of the kindred corps with rapidity and precision, topography should be studied with great attention, for most frequently it happens that circumstances do not allow time to do these things with deliberation. PRINCIPLE _Acting either offensively or defensively, one never should proceed in such a way as to allow the enemy the advantage of ground;_ That is to say: Kindred corps never should be exposed to unopposed adverse radii of offence, when the effect of such exposure is the loss of kindred material, or of time much better to be employed, than in making a necessary and servile retreat from an untenable post. On the contrary, every kindred topographical advantage should unhesitatingly be availed of; and particular attention continually should be paid to advancing the kindred corps to points offensive where they cannot be successfully attacked. Pains always must be taken to select advantageous ground. Indifferent posts must never be occupied from sheer indolence or from over-confidence in the strength of the kindred, or the weakness of the adverse army.