at night. The latter
appears to have been planted in place.

[Illustration: Fig. 10]

[Illustration: Fig. 11]

=1181. A wire entanglement= is composed of stakes driven in the ground
and connected by wire, barbed is the best, passing horizontally or
diagonally, or both. The stakes are roughly in rectangular or quincunx
order, but slight irregularities, both of position and height should
be introduced.

In the =high entanglement= the stakes average 4 feet from the ground,
and the wiring is horizontal and diagonal, Fig. 12.

[Illustration: Fig. 12

_High wire entanglement showing method of linking posts head to foot
and foot to head. Wire, plain or barbed, then festooned with barbed
wire. Bind wires where they cross. Use broken bottles, crows feet,
planks with spikes or fishhooks in conjunction with this
entanglement._ (From _Knowledge of War_--Lake.)]

=The low wire entanglement= has stakes averaging 18 inches above the
ground and the wire is horizontal only. This form is especially
effective if concealed in high grass. In both kinds the wires should
be wound around the stakes and stapled and passed loosely from one
stake to the next. When two or more wires cross they should be tied
together. Barbed wire is more difficult to string but better when
done. The most practicable form results from the use of barbed wire
for the horizontal strands and smooth wire for the rest.

This is the most generally, useful of all obstacles because of the
rapidity of construction, the difficulty of removal, the comparatively
slight injury from artillery fire, and its independence of local
material supplies.

=1182. Time and materials.= One man can make 10 sq. yds. of low and 3
sq. yds. of high entanglement per hour. The low form requires 10 feet
of wire per sq. yd. and the high 30 feet. No. 14 is a suitable size.
The smooth wire runs 58.9 ft. to the lb. A 100-lb. coil will make 600
sq. yds. of low or 200 sq. yds. of high entanglement. If barbed wire
is used, the weight will be about 2-1/2 times as much.

=1183. Wire fence.= An ordinary barbed-wire fence is a considerable
obstacle if well swept by fire. It becomes more formidable if a ditch
is dug on one or both sides to obstruct the passage of wheels after
the fence has been cut. The fence is much more difficult to get
through if provided with an apron on one or both sides, inclined at an
angle of about 45 deg., as indicated in Figs. 13 and 14. This form was
much used in Sout