Trenches are laid out and dug as shown in the accompanying diagram [Figure 4]. They do not consist of one long straight line, but what may be described as a succession of little rooms, about twenty feet long, seven feet deep and three feet broad. They are seldom roofed over. Each little room is connected to the ones on either side by a trench that runs behind the four-feet-square traverse that is of solid earth and which serves the purpose of localising the effect of shells, bombs, etc. If the trenches were in one straight line, a shell that fell there would be liable to injure a great many men; whereas under the present system the traverse acts as a buffer and limits the radius of its explosive force. The trench itself is dug about three feet deep, care being taken to lift off the top layer of grass and keep it aside to place over the front of the earth on completion of the trenches, to render them less visible. As the earth is lifted out it is thrown to the front and rear, and some of it put into sandbags which are then laid like stones as shown. The front part of the trench is then called the parapet and the rear part the parados. Both must be made strong, the parapet for reasons already given, and the parados in order to protect the men from the force of shells that fall just behind the trenches. About a foot from the ground there is placed a board that is called the "firing step," on which the men stand when they are about to fire. I have said that there is seldom any roof over the trenches. It is difficult to cover in the trenches because of the limited supply of materials. Then again it is questionable if roofing pays; for, admitting that they may be able to keep out small bombs and rifle bullets, they can never hope to be able to keep out shells. The Germans used to roof in a great deal--but then they were there to wage a defensive war and did not propose to move for a good while. In some ground the earth will "hold itself up" at the sides of the trenches, in other ground it will have to be revetted. This is done with chicken wire, or with willows or old staves where they can be had. It is important to have the sides firm, or else in wet weather especially, they will prove a nuisance to the occupants of the trenches. Some kind of floor should be provided for the trenches. The simplest and best are made in the following way: Take two seven-inch boards about ten feet in length, nail them together to make a fourteen-inch plank, and then cover the whole with fairly fine chicken wire. Place these boards on the ground with the side on which the wires are joined downwards. They keep the feet from slipping, are easily cleaned by being upended when they are dry, and allow the space under them to be reached easily to pick up scraps of food, etc. There is nothing more heart breaking than having to pursue your weary course for miles, sometimes, up trenches with slippery sides and sloping, wet, treacherous bottoms.