9. A log of events hour by hour should be kept which shows every item of enemy activity and the measures taken during the tour in the trenches. This will be a valuable reference when turning the trench over and will make a record of the habits of the enemy that may be most valuable as a guide for making plans to circumvent him.
10. The police and sanitation of the trenches will be carefully looked after.
11. Platoon commanders may divide the tour of supervision of the platoon sector with the squad leaders.
12. The whole company stands to arms during the hour before dawn.
Observation
Plate 43.
Observation of the enemy's line should be continuous. The observation and firing system will be arranged so that all parts of the enemy's line will be under observation and fire at all times.
Plate 42 shows the arrangement in general. The appliances for carrying it out are shown in Plates 43, 44 and 45.