As before mentioned, in the space between the front lines of the opposing armies, which is known as No Man’s Land, there are sometimes large and sometimes small areas of ground, ditches, streams, etc., which cannot be satisfactorily watched from a fire trench immediately facing them, owing to the lay of the land, hedges, old excavations, buildings, etc. This is the case in a great many instances regardless of the careful thought and the amount of time spent in siting a fire-trench, as the siting of all trenches is largely subsidized by the tactical position of the flank trenches. Very often a line of trenches is taken up under stress of circumstances that do not permit of the obeying of the rules and standards set for an ideal fire-trench. The control of these areas is essential to prevent small surprise attacks, cutting-out parties and raids. During the day they are very often observable from a flank trench or higher observation ground in the rear, but at night this is not possible; so that listening or observation posts are gradually sited in front of the fire trench with due consideration to the situation in that immediate vicinity. A ruined shed, shack, cart, or any other thing of a similar character lying in No Man’s Land is very useful for these purposes if it can be reached before the enemy reach it with the same purpose in mind. This cannot be used very long, as its purpose is too obvious and peace and quietness will not last long, but it will do until a more satisfactory arrangement can be made. The listening post is often dug just inside the outer fringe of your own barbed wire entanglements, and is just large enough to allow two men to stand in unobserved. It should be reached by a very narrow, irregular trench running out from a fire-bay, where it is fairly easy to secure the maximum amount of concealment necessary to give protection. The soil excavated from these places must not be thrown out, but placed in sand bags and taken into the trench and used there. It is always best and requires very little more labor, and gives the maximum amount of protection to your listening post if communication to it be made through a tunnel. These things are bound to be discovered within a certain amount of time, and when you know the position of your listening post has been found by the enemy, which you will know very quickly, owing to the amount of bombs and rifle fire it will receive for one or two nights, until you can dig another one, it is a safe thing to build up a small parapet, taking it down every morning before dawn. It then becomes necessary to dig a new post, and this can be generally done by leading off from your old communication trench to some more favorable spot. When the new post is ready for occupancy, the old one should be filled in with barbed wire, or completely filled in again with dirt, and the sandbag parapet left to mislead as long as possible.