_After the battle_, it must protect the attacking troops who have reached their objectives, from enemy counter-attacks, by barrage fire. [Illustration: CAMOUFLAGED HEAVY GUN ABOUT TO FIRE.] [Illustration: THE CAPTURE OF VERMANDOVILLERS. _The arrival of French reinforcements. Photographed from accompanying aeroplane at 600 feet (p. 128)._] The Infantry _Before the battle_, the attacking troops assemble first in the shelters, then in the assembling places and parallels made during the previous night. The battalion, company and section commanders survey the ground of attack with field-glasses. _During the battle_, at a given signal, the assaulting battalions dash forward from the departure trenches, the first wave deployed in skirmishing order; the second and third, consisting of trench-cleaners, machine-gunners and supports, follow thirty or forty yards behind, in short columns (single file or two abreast). Reinforcements _echeloned_, and likewise in small columns, bring up the rear, 150 to 200 yards behind. As a matter of fact, in actual fighting, each regiment attacks separately. The Commandant, realising the difficulties on the spot, must have in hand all the necessary means of success, the most powerful being the artillery, which accompanies and prepares each phase and development of the attack. Generally, the creeping barrage, timed beforehand, is loosed at the same moment of time as the assaulting wave. The infantry follows as closely as possible. [Illustration: INFANTRY ADVANCE. _The attacking waves mark their advance with Bengal lights._] Constant and perfect _liaison_ is necessary between the infantry and artillery. This is ensured by means of runners, pennons, panels, telephones, optical telegraphy, signals, rockets, Bengal lights, etc. A similar _liaison_ is ensured between the various attacking units, on the right, left and behind. Action must be co-ordinated, an essential point on which the G.H.Q. always strongly insist. As soon as the enemy perceives the assaulting waves, every effort is made to scatter them by means of artillery barrage and machine-gun fire, asphyxiating gas, grenades and liquid fire, so that generally the storming troops cross "no man's land" through a veritable screen of fire. The enemy's fire likewise extends to the first-line trenches, to cut off the first waves from their supports.