6. The guns should be located so that they support each other by their fire. Alternate positions should be constructed.
7. When located to enfilade straight lines of trenches, special capioniers should be constructed.
Supporting Points
At intervals from 800 to 1,500 yards along the first line, supporting points are established. They may consist of a fortified village or a specially prepared position having a "labyrinth" of trenches and rendered well nigh impregnable to infantry assault by every defensive device known to modern warfare. They are designed to bring a flanking fire to bear upon the intervening intervals with the idea that troops cannot pass beyond them until they are reduced.
Village Defense
The following was the actual scheme employed for the defense of a French village, and exemplifies the thoroughness with which defenses must be organized.
The village was about 700 yards in rear of the front line, and had three keeps surrounded with wire entanglements and independent of each other, but with an elaborate system of communication trenches. Water and four days' rations were stored in each keep, and wells dug. Each of the keeps held about one company. The communication trenches were about 6 feet deep, used as far as possible as fire trenches, and well traversed. Firing platforms were revetted with brushwood, and shelters made all over the village. In addition to keeps, a series of lines existed in the rear of the front line, intercommunicating and provided with barbed wire. A small wood on one point of the front was defended by a network of low wire entanglements and a line of high wire netting.
Every officer had to know all about his section and its communications with right and left. Telephone wires were laid low down in communication trenches and fastened a few inches from ground with wooden pickets.
Machine guns were placed so as to flank salients. A 65-mm. field gun was placed in the front line to sweep the village, and an observation station placed in a tree. The observer wore a green mask and green sheet.
Great use was made of brushwood and undergrowth to revet steps of firing platform.