"The subordinate commanders must bring to fruit with all the means at their disposal the scheme of the higher command, therefore they must, above all, understand that thought and then make of their means the use best suited to circumstances--of which, however, they are the only judge. . . . The Commander-in-Chief cannot take the place of his subordinates--he cannot think and decide for them. In order to think straight and to decide rightly it would be necessary for him to see through their eyes, to look at things from the place in which they actually stand, to be everywhere at the same moment" (Marshal Foch). Students of military history will remember that the Prussian Commander-in-Chief and his Chief Staff Officer, during the highly successful campaign of 1870-71, did not come within sound of the guns until five pitched battles had been fought by their subordinate commanders. Outside the fog of battle, with its absorbing interests and distractions, the commander can retain his sense of proportion[1] and can decide where and when he will make his final effort. News of the battle reaches him from his immediate subordinates, and from the accounts of successes and failures he is able to judge the weaknesses and strength of his own and his adversary's dispositions, to use part of his reserves as reinforcements, {35} if he must, or to husband them with confidence in the success of the operations, until the time comes for him to launch them for the final blow. INFORMATION.--In order that the commander's influence may be exerted to the best advantage it is essential that all vital information should reach him promptly, and that his orders should be communicated without delay. Subordinate commanders must keep their superiors and commanders of neighbouring units regularly informed as to the progress of the battle, and of important changes in the situation as they occur. Runners, who can be trusted to carry a verbal message or written order, are attached to each unit engaged and to its headquarters. Higher units than battalions can usually depend on the Signal Service for intercommunication, but whenever necessary, a supply of runners and mounted orderlies must be available for their use. This ensures co-operation, and enables mutual support to be rendered. Information received must be transmitted at once to all whom it concerns, and orders received from superiors must be communicated without delay to commanders of all units affected.