s an auger, so that the posts can be
quietly screwed into the ground at night and the wire attached.
Another method of placing wire entanglements is to make them in
sections and roll them up. These sections are usually about 20 feet
long, the wire firmly fastened to the sharpened stakes. At a favorable
moment the soldiers rush out, unrolling the sections as they go and
with mauls quickly drive the stakes. Loose ends of wire enable the
sections to be bound together as placed.

Another form of wire entanglement is shown in (Fig. 18). Triangular
pyramids 3 feet 6 inches high are made of poles or timber. The
pyramids are usually arranged in pairs with the wire on three faces so
that, no matter if the obstacle is rolled over, a wire fence is
presented. These obstacles are carried out and placed so as to break
joints and are staked down as soon as possible.

[Illustration: Fig. 18

Substitute for Posts.]

The wire used for entanglements is found more convenient to handle
when wound on a stake a yard in length, in a sort of figure eight
winding. Special barbed wire of heavier material and barbs placed
close together has been found much more effective than the commercial
barbed wire.

In some localities electrified wire has been used. In such cases the
obstacle is charged in sections, so that, if one section is grounded
it will not affect the others.

=1189. Wire cheveaux de frise.= Two forms of this obstacle have
appeared. Both are portable. They consist of two or more wooden
crosses fastened at their centers to a long pole and connected with
each other by barbed wire. This obstacle retains its effectiveness
when rolled over. (Figs. 19 and 20) give an idea of their
construction. The form shown in (Fig. 19) is often made small enough
for individuals to carry. These are prepared in the trenches and used
for throwing into one's own entanglements to make them more complex or
may be carried when making an assault and thrown into the enemy's
trenches to prevent movements from one part of the trench to another.
The long stick projects out of the end to be used as a handle.

[Illustration: Fig. 19

Wire Cheveaux de Frise]

[Illustration: Fig. 20

Wire Cheveaux de Frise]

=1190. Guarding obstacles.= It has been found necessary to keep a
constant watch over obstacles after they have been placed.

=1191. Listening posts.= One of the best methods is to post one or
more men in listening posts in or beyond the line of obsta