our ever industrious and systematic enemy. =Note.--In the following lectures blackboard illustrations may be used with good results.= LECTURE V. FRONTAL ATTACK. =Preparation and Organization.= In trench warfare, when our movements are changed from the defensive to the offensive, it is necessary to choose certain sections of the enemy’s front line of trenches. These are chosen from a tactical point of view, and after having been occupied and consolidated to our use become the bases from which enfilade attacks are directed to the flanks and front, by means of which we extend and connect our positions. The Officers and their Staffs ordering the offensive, make a very careful study of the neighborhood in the sections to be occupied from maps and sketches which have been compiled from information gained by the Air Service and Reconnaisance. They finally decide the exact extent of front which will be occupied in each case by direct frontal attack. The extent of front in each case is never greater than is absolutely necessary, and is clearly defined in orders. Every officer taking a part in the assault is supplied with maps and sketches, which constitute part of his orders. (Note the necessity for every officer being able to make a study of a locality from information given on maps and sketches.) Arrangements are made for the co-operation of the different arms of the service taking part in the assault, such as the engineers, artillery, air service and infantry. A schedule or program is arranged covering the movements of the different arms of the service, which are carried out by time-table, each Officer and Non-Commissioned Officer having correct divisional time. Arrangements are made for reinforcements, ammunition, supplies and materials necessary to carry out the attack and consolidate the new positions to be taken, also for the establishment and maintenance of communication. Artillery fire is directed on the positions to be occupied, also on the trenches to each flank and the rear of the same, and on the enemy’s obstacles for a period of from thirty minutes to several hours prior to the advancing of the infantry. Saps are run out in front of our obstacles and as much progress as possible is made in joining up the sapheads to form a new line of trenches from which to deliver the actual assault without the hindrance of our own obstacles. Our troops are massed as near as possible to the front line in readiness for the assault. The supplies of ammunition and material are brought forward to as convenient a position as possible, to be taken into the new position at the first opportunity. Saps are extended towards the enemy’s machine gun positions and any positions from which they could supply cover fire, and bombs are thrown from these to finish the work of the artillery in the destruction of the same.