s
the manoeuvre of Napoleon at Donawert in 1805, at Jena in 1806, and at
Ratisbon in 1809.

_Interior_ lines of operations, when properly conducted, have almost
invariably led to success: indeed every instance of failure may be
clearly traced to great unskilfulness in their execution, or to other
extraneous circumstances of the campaign. There may, however, be cases
where it will be preferable to direct our forces on the enemy's flank;
the geographical character of the theatre of war, the position of other
collateral forces, &c., rendering such a direction necessary. But as a
general rule, interior and central lines, for an army of moderate
forces, will lead to decisive results.

Napoleon's Italian campaigns in 1796 and 1797, the campaign of the
Archduke Charles in 1796, Napoleon's campaigns of 1805 and 1809 against
Austria, and of 1806 and 1807 against Prussia and Russia, of 1808 in
Spain, his manoeuvres in 1814, between the battle of Brienne and that
of Paris, and his operations previous to the Battle of Ligny in 1815,
are all brilliant examples under this head.

To change the line of operations, in the middle of a campaign, and
follow _accidental lines_, is always a delicate affair, and can only be
resorted to by a general of great skill, and with disciplined troops. In
such a case it may be attended with important results. It was one of
Napoleon's maxims, that "a line of operations, when once chosen, should
never be abandoned." This maxim, however, must sometimes be disregarded
by an army of undisciplined troops, in order to avoid entire
destruction; but the total abandonment of a line of operations is always
attended with great loss, and should be regarded as a mere choice of
evils. A regular army can always avoid this result, by changing the
direction of its line; thus frequently gaining superior advantages in
the new theatre of action. If the plan of this change be the result of a
good _coup d'oeil_, and it be skilfully executed, the rear of the
operating army will be secure from the enemy; and moreover, he will be
left in doubt respecting its weak points. But such is the uncertainty of
this manoeuvre, that it is very rarely taken by the best troops, unless
actually forced upon them. If the army be of incongruous materials,
generally a change of direction will be less advantageous than to
entirely abandon the line, and save as many as possible of the troops
for some new plan of operations. (Maxim 20.) If, howe