2. OFFENSIVE REINFORCEMENT OF A FRONT MOMENTARILY STATIONARY.--The machine guns assisted by small elements of infantry cover thoroughly the getting in hand of the main body, the machine guns presenting to the enemy a line of little vulnerability. The machine guns assist in securing the possession of the ground previously taken, and will permit time to prepare for the resumption of the forward movement. Preparation of the attack--machine gun fire completes the preparation done by the artillery, either by acting on the personnel or by opening breaches in the accessary defenses. At times the machine guns alone may be charged with the preparation of the attack where it is necessary to act very quickly as in pursuit, exploitation of a success. Whatever the situation, concentrate the machine gun fire on one or several points. Machine guns cover the flanks of attacking troops. They follow the advance of these troops remaining on the flanks, so as to be able to fire instantly on all points from which an attack might come. Machine guns will likewise be employed in intervals created intentionally or accidentally between units. It is here a powerful weapon which can rapidly be put into action by the Commander. The personnel and material must be protected as far as possible from the effects of fire. 3. DEFENSIVE.--It is here that the flanking fire is especially necessary. In the defensive preparation of a position the machine guns must be so placed that they will provide along the front several successive fire barriers. The machine guns must be ready at all times to stop by instantaneous fire all hostile attack. In order to have machine gun protection at all, it is absolutely necessary that they be protected from bombardment. This is best done by the following: Place the machine guns under solid cover; make their emplacement invisible; echelon the machine guns in depth. The cover must be placed where it can be hidden from the sight of the enemy, such as a counter slope, a position where it is impossible to blend it, relief with an accentuated slope of the ground, woods, brush, etc. It is essential that the principal parts of the machine gun casemate be prepared in the rear. Only in this manner will the work be done solidly and rapidly. While the machine gunners and helpers do the excavating, specialists in rear prepare the parts for assembling. The latter are then transported to the position and, the casemate is established, hiding the work with the greatest care from enemy observation. Remember that it is of the utmost importance that the machine gun be invisible, so the firing emplacements must be made outside of the shelter, but near enough for the gun to be brought out instantly and put into action. All communicating trenches leading to the firing emplacement must be concealed. Enough emplacements should be built to avoid firing daily from the emplacements especially reserved for cases of attack.