particularly within
close range, from which the enemy will endeavour to establish an
ascendency in the fire-fight.

(iv) _The flanks must be secure_, or at least as strong as possible. A
flank resting on a deep river or a marsh may be regarded as secure, and
a flank extending to the sea, or to the boundary of a neutral State. A
flank on high ground which commands all approaches and provides means
of distant observation may be called strong. It is a great advantage
if one flank can be posted so strongly as to compel the enemy to make
his main attack on the other, as this will enable the defender to
forecast the direction of the decisive attack and to dispose his
General Reserve to meet and overwhelm it.

(v) _There should be facilities for cover_ on the position and
concealed avenues of approach from the rear. A crest affords cover on
the reverse slopes and woods provide concealment, while time enables
artificial means to be adopted. Tactical cover can be provided by
cavalry and advanced troops in the early stages of manoeuvre-battle,
and in removing this cover the troops can withdraw in such a way as to
lure the enemy on {89} to a false position. They can also induce
premature deployments by the enemy, and movements across the front of
the real position.

(vi) _There should be good artillery positions_ to provide effective
fire on all hostile avenues of approach, and counter-battery work on
hostile artillery positions. There should also be firm ground and good
roads for the movement of guns, and an absence of landmarks for the
enemy to range on. Guns of the heaviest calibre take part in all
modern battles, their disposition being settled in conference with the
artillery commander. A battery of field artillery requires 100 yards
frontage for its six guns, and there is usually an interval of 25 yards
between batteries.

(vii) _There must be depth_ to allow for the disposal and movement of
the Supports and Reserves, and for manoeuvres to recapture the forward
defences, or to issue to the counter-attack.

(viii) _There must be good lateral and frontal communication_ in order
that any part of the line can be quickly reinforced. A position
astride an unfordable stream, or high ridge or deep ravine should
therefore be avoided. At the _Battle of Dresden_ (August 26, 1813) the
Allies were encamped on the left bank of the Elbe. Their forces were
posted on the heights, but the position was cut transversely by a