=4. STANDING TO ARMS.=--Troops will always stand to arms one hour before daylight and one hour before dark. They will remain under arms in the first instance until the enemy's lines are visible, and in the second instance until darkness comes on. At these hours company commanders will arrange for the inspection of arms, ammunition, and equipment by platoon commanders. The latter will satisfy themselves that each man is in possession of two smoke helmets; ammunition will be made up to 120 rounds per rifle when troops stand to arms. Whenever men stand to arms company commanders will order the parapet to be manned to insure that every man has a post from which he can fire at the bottom of our own wire. At the inspection of rifles at the hours of standing to arms platoon commanders will satisfy themselves that the bolt action is working freely. A thorough inspection of arms will be held at midday, at which hour men will be washed and shaved. =5. GAS ATTACKS.=--(i) It is to be impressed on all ranks that the smoke helmet issued to them affords complete protection against all forms of gas used by the enemy. (ii) All ranks will invariably carry on their persons smoke helmets. Instruction is to be given in the method of adjusting smoke helmets rapidly, condemned helmets being used for this purpose. (iii) Smoke helmets will be inspected at morning and evening "stand to." (iv) The direction of the wind will be studied and special precautions taken when it favors a gas attack by the enemy. (v) On the first sign of gas, whether it is detected by sight or smell, the sentries will sound the alarm gongs and bells which are hung up at intervals throughout the trenches. On hearing this alarm every officer and man will at once adjust his smoke helmet and fall in on his alarm post. Nobody will remain in dugouts. To make certain of the warning reaching everybody the order "Put on smoke helmets" will be passed from man to man throughout the trenches held by the ---- division. (vi) The officers in command of the trenches opposite the section of the enemy's line from which the gas is proceeding will send the S. O. S. call to the artillery, and will order rapid fire to be opened on the enemy trenches. Neighboring sectors of defense will be at once warned. (vii) When the gas cloud is sufficiently thick to hide the enemy's front parapets, machine guns and rifles will open fire in short bursts on fixed lines covering the enemy's trenches, in order to inflict casualties, pierce gas tubes, and break up the density of the enemy's gas cloud. (viii) Garrisons of trenches on the flanks of the front threatened will be prepared to open a flanking fire on the enemy should he attempt to advance from his front line. (ix) As soon as the S. O. S. call has been sent to the artillery, messages will be sent to brigade H. Q. and the artillery "Gas trench(es)________________________________."