SKETCH OF TRENCH SYSTEM] SECTION I. C. T. should start behind one of the fire-trench traverses and not from a fire-bay. Every yard should be contestable for approximately the first 15 to 20 yards. This can be effected, and at the same time the effect of hostile artillery and rifle fire and bombs localized, by a series of traverses 9 feet square, the trench being approximately 7 feet deep and 2 feet wide at the bottom. Cut into the rear of a few of these traverses is a narrow recess through which one of the defending bombing party may take up a position in the center of the traverse and fire, kneeling or standing, through a loophole at the advancing enemy. The recess gives him ample protection, including head cover, and is so cut that the entrance is out of alignment with the trench behind him and he will be unaffected by a bomb exploding there. At the same time he may work with, and direct, the bombers behind him who are bombing over the traverse, and if it becomes necessary, they can also take cover in the entrance to the recess. The loophole should not be placed so high that it becomes possible for the enemy to come forward under it. The most dutiable arms for the members of the defending bombing party detailed for this traverse work are what are known as “close-contact weapons,” generally including revolvers, bombs, trench knives, and very often a bayonet carried by pushing it down in the puttee. [Illustration: SECTION II SKETCH OF TRENCH SYSTEM] SECTION II. The time and claims of rapid transit will not allow the traverse system as employed in Section I to be continued, the narrow single-traffic C. T.’s, from wear and tear and shell fire, soon become wider, and as the width would allow rapid transit to friend and foe alike, it is of the utmost importance that some means be adopted to deprive the enemy of this advantage. Moreover, the enemy may have successfully advanced down on traversed C. T., say, at “C,” and our own bombers might still be fighting in another traversed C. T., say, at “D,” and their needs demand protection. This may be obtained if, before the single C. T.’s merge into the double, each of them be quite straight for approximately 15 yards, and island-traverse, “E,” be placed at the junction. In the rear of this island, “E,” is a large and substantial recess, into which one or two Lewis guns or automatic rifles can be placed, firing through loopholes and rendering hostile advance down both “C” and “D” communication trenches almost impossible. The recess in “E” must allow ample room in which to operate. Overhead cover is provided, and one rifle would require one long loophole, so that it could fire along either C. T. without more than a moment’s interruption. In the case of two rifles being available, there could be two such long loopholes, each covering both C. T.’s, one for kneeling and one for standing. The lower loophole gives the advantage of it being impossible for any of the enemy to get out of danger beneath it.