The commander-in-chief and his staff occupy what is called the general headquarters of the army, which is stationed in some town behind the area in which fighting is actually going on. Battles are now waged over so many miles that a commander-in-chief cannot possibly see for himself what is happening all along his line. He has to rely upon others, who bring him or send him information by telegraph, telephone, motor car, motor cycle, or aircraft. All day, and all night too, a constant stream of information as to the movements of the enemy, the position of his own troops, the progress of the fighting, and so forth, arrives at the headquarters of a commander-in-chief, and officers are set apart to receive this information and arrange it so that he may have a clear and full knowledge of all that is going on. Large maps are spread out on tables, and officers are constantly engaged in marking the movements of each side by means of flags or coloured chalks, so that at a glance the situation at any given moment may be seen. It is by the study of these marked maps that the commander and his staff decide what movements the army shall make to resist or attack the enemy. [Illustration: This picture represents the headquarters of a French division in a village. Notice the cavalry and cyclist scouts and the men receiving messages by telephone. Notice also the officers writing orders and poring over maps.] Each army corps, division, and brigade has a similar headquarters, where the same kind of work is done and information is gathered up to be sent to the general headquarters, or the G.H.Q., as soldiers call it. As the army moves backwards or forwards, general headquarters is moved from one place to another; but it is always far enough in the rear not to be disturbed by the guns of the enemy, and in such a position that it can easily be in touch with every part of the fighting line. It often happens that the commander wishes to be in closer touch with the operations that are going on, or perhaps he desires to meet his generals in order to consult with them, and to receive their reports in person. For this purpose he has report-centres, or what are called _postes de commandement_, nearer the front than general headquarters. Between the general headquarters and the headquarters of army corps officers constantly travel to and fro in motor cars. They carry messages to the various generals, and, if necessary, explain the commander's wishes to them more fully than could be done in writing. [Illustration: In Trenches. These trenches have been occupied for a considerable time, and much has been done to make them habitable. Notice the parapet behind which the men stand to fire, and the dug-out in which they take refuge when the trench is heavily shelled. Photopress.]