7. Each squad establishes a double sentinel post in the bay assigned to it and the remaining members go into the squad shelters just in rear of the bays. This gives three reliefs for a double sentinel post and allows one extra man to be utilized as "runner," etc. 8. The remainder of the company is established in the company dugouts. 9. Depending upon the length of the tours of duty of the company in the first line trenches, the squads are changed according to a system that will have to be varied to suit the occasion, the squads in support taking their place in the fire trench and those in the fire trench returning to the support. GOING INTO THE TRENCHES Platoons enter by not more than two squads at one time, thus minimizing the danger from shell fire. The platoon commander will explain to his squad leaders the extent of trench to be taken over and the action to be taken in case they are caught under shell fire or rapid fire while going up to the trenches. A second in command in each squad will be designated, so that if casualties occur among the squad leaders the relief will proceed as previously arranged. The operation will proceed in silence. Rifles must be carried so that they do not show over the parapet. On reaching the fire trench the men of the first relief are posted to relieve the old detail and each man finds out any points that may be useful from his predecessor on that post. INFORMATION TO BE OBTAINED The platoon commander confers with the commander of the outgoing party and secures all the information possible about the position which includes: 1. Behavior of enemy during period preceding relief, and any point in their line requiring special information, _e.g._, enemy may have cut wire as though preparing to attack. [Illustration: Plate 42.] 2. Machine-gun emplacement may be suspected at some particular point. 3. Anything ascertained by patrols about ground between firing lines, thus avoiding unnnecessary reconnaissance. 4. Any standing arrangements for patrols at night, including point at which wire can best be passed, ground to be patrolled, or place where they can lie under cover. 5. Any parts of trench from which it is not safe to fire. Such positions are apt to occur in winding trenches, and are not always recognizable in the dark. 6. Special features of trench, recent improvements, work not completed, dangerous points (on which machine guns are trained at night), useful loopholes for observation. 7. Places from which food and water can be safely obtained. 8. Amount of ammunition, number of picks, shovels and empty sandbags in that section of the line. Information on these points cannot always be given properly by word of mouth. _Written_ notes and plans should therefore be handed over to a platoon commander taking over for the first time.