(2) Head or overhead cover concealment.
(3) Placing obstacles and recording ranges.
(4) Cover trenches for supports and local reserves.
(5) Communicating trenches.
(6) Widening and deepening of trench; interior conveniences.
Now having cleared the foreground, dug the trenches, recorded ranges to the important objects in each sector, etc., the position can be occupied. The citizen ordinarily pictures the firing trench full of soldiers when he is told the trenches are occupied. Not so. Patrols would be operating well to the front to give timely warning to one or two sentinels in each company fire trench of the approach of the enemy. These sentinels would in turn inform the company which would probably be resting in the trenches in the rear.
THE ACTUAL DEFENSE
Let us suppose now that our battalion, occupying this defensive position, is a part of a larger force which is supported by artillery. You see small objects one and a half to two miles to your front. You know they are the enemy's troops because your artillery is firing at them and your combat patrols are being driven in. Your entire company has moved to its fire trench. You have plenty of ammunition, you know exactly the range.
What happens? You open fire on the enemy at probably the extreme range of 2000 yards. Only the hostile artillery can return this fire until the enemy's firing line closes to within 1200 yards of your position. While an attacking force is thus approaching you may inflict very serious losses upon it. But it cannot stop, however serious its losses, beyond 1200 yards; for we have seen that, if it stops advancing in order to fire, it will probably never arrive at your position. When within 1200 yards the enemy will build up a strong rifle fire against you and not attempt to advance until he has gained fire superiority. It is your business not to let him get fire superiority, and if he does do so to take it away from him when he withdraws parts of his rifles to advance by rushing. Fight each rush. If your defense is active and you permanently stop the enemy's advance by gaining fire superiority, and he cannot regain it, even though he uses up his supports, his firing line will become confused and demoralized and it will be the psychological time for the proper commander to launch his counter attack. On the other hand, if you cannot stop his advance, fix bayonets (firing line and remaining supports) when he fixes bayonets and meet his charge in front of your trench. All your supports will be moved up to assist you in opposing the charge. If you are unsuccessful in the bayonet fight or forced to retire from your trenches during the fire fight your artillery, cavalry and any formed reserves in the rear will cover your withdrawal, which, if possible, should be made straight to the rear, one part covering the withdrawal of the other part, and so on. Reorganize at the first opportunity.