s will never long occupy the relative perpendicular positions
indicated in these figures; for if the army B were to take its first
position on a line perpendicular to one or both extremities of the army
A, the latter would at once change the front of a portion of its line;
and even the army B, as soon as it extended itself to or beyond the
extremity of A, must of necessity turn its columns either to the right
or the left, in order to bring them near the enemy's line, and so take
him in reverse, as at C, the result being two oblique lines, as shown in
Fig. 10. The inference is that one division of the assailing army would
take a position perpendicular to the enemy's wing, whilst the remainder
of the army would approach in front for the purpose of annoying him; and
this would always bring us back to one of the oblique orders shown in
Figures 9 and 16.

The attack on both wings, whatever be the form of attack adopted, may be
very advantageous, but it is only admissible when the assailant is very
decidedly superior in numbers; for, if the fundamental principle is to
bring the main strength of the forces upon the decisive point, a weaker
army would violate it in directing a divided attack against a superior
force. This truth will be clearly demonstrated farther on.

[Illustration: Fig. 12.]

The order concave in the center (Fig. 12) has found advocates since the
day when Hannibal by its use gained the battle of Cannae. This order may
indeed be very good when the progress of the battle itself gives rise to
it; that is, when the enemy attacks the center, this retires before him,
and he suffers himself to be enveloped by the wings. But, if this order
is adopted before the battle begins, the enemy, instead of falling on
the center, has only to attack the wings, which present their
extremities and are in precisely the same relative situation as if they
had been assailed in flank. This order would, therefore, be scarcely
ever used except against an enemy who had taken the convex order to
fight a battle, as will be seen farther on.

[Illustration: Fig. 12, _bis_.]

An army will rarely form a semicircle, preferring rather a broken line
with the center retired, (Fig. 12, _bis_.) If several writers may be
believed, such an arrangement gave the victory to the English on the
famous days of Crecy and Agincourt. This order is certainly better than
a semicircle, since it does not so much present the flank to attack,
whilst allowing fo