Position.--Dugouts must always be on the side of the trench toward the enemy. This prevents flying shells from falling into the entrances. They should connect with lateral trenches, not with boyaux, as men at the entrance obstruct traffic through the boyaux. Entrances and exits must be well concealed, with not less than five feet of head cover. This should be provided with a bursting layer. All dugouts must have at least two openings, one on the opposite side of the traverse or angle from the other. It is well to have an exit behind the parados leading to a surprise position for a machine gun and bombers. All openings must have a sill 6 inches to 8 inches high, to prevent water from entering the dugout. Galleries leading to dugouts should be built at an incline of 45 degrees. Their dimensions should be 2 feet 6 inches by 6 feet. Frames are of squared timber. The sill and two side posts should be not less than 6 inches square, and the frames in the passageways 2 feet 6 inches by 4 feet 6 inches. They must be placed at right angles to the slope of the gallery, with distance pieces between uprights. In treacherous soil the frames rest on sills. Steps in the passageway are 1 foot broad and 1 foot high. Bomb-traps, extensions of the gallery about 3 feet long, should be dug beyond the point where the entrance to the dugout chamber leads off from the gallery. These will catch bombs thrown in from the surface and protect the chamber from the effects of their explosion. Interior. The standard section is 6 feet by 8 feet, to allow for bunks on each side. Frames of 6 by 6 timber spaced 2 feet 6 inches apart support the sides and roof. Roof planking should be 2 inches thick, and the sides should be covered with 1-1/2 inch plank or corrugated iron. Two shovels and two picks for emergencies should always be kept in each dugout. The construction of the chamber should be that of a very strong box, so that it will stand strain, if necessary, from within as well as from without. Depots for Supplies must be near the headquarters of the platoon, company, battalion and regiment. Shelters may be made with ammunition boxes set into the side of the trench. Places should be provided for the following: Food, ammunition for rifles and auto-rifles, grenades, rockets, tools and other supplies. Places must also be arranged in the front line for ammunition, rockets and hand and rifle grenades. Telephones. Communication is established as speedily as possible with the various units. In the forward trenches wires do not last long under bombardment and fire left open along the side of the trench, where quick repairs can be made. All soldiers must be taught to respect these wires and to care for them when they are found under foot or hanging. Conduits are dug for wires to battalion and regimental headquarters, and these are fairly safe from shell fire.