much ostentation, the concentration of an army on the Elbe sixty
thousand strong, its object being to protect Hamburg against the English
and to influence Austria, whose disposition was as manifest as her
interests.

The Prussians established a similar reserve in 1806 at Halle, but it was
badly posted: if it had been established upon the Elbe at Wittenberg or
Dessau, and had done its duty, it might have saved the army by giving
Prince Hohenlohe and Bluecher time to reach Berlin, or at least Stettin.

These reserves are particularly useful when the configuration of the
country leads to double fronts of operations: they then fulfill the
double object of observing the second front, and, in case of necessity,
of aiding the operations of the main army when the enemy threatens its
flanks or a reverse compels it to fall back toward this reserve.

Of course, care must be taken not to create dangerous detachments, and
whenever these reserves can be dispensed with, it should be done, or the
troops in the depots only be employed as reserves. It is only in distant
invasions and sometimes on our own soil that they are useful: if the
scene of hostilities be but five or six marches distant from the
frontier, they are quite superfluous. At home they may generally be
dispensed with: it is only in the case of a serious invasion, when new
levies are organizing, that such a reserve, in an intrenched camp, under
the protection of a fortress which serves as a great depot, will be
indispensable.

The general's talents will be exercised in judging of the use of these
reserves according to the state of the country, the length of the line
of operations, the nature of the fortified points, and the proximity of
a hostile state. He also decides upon their position, and endeavors to
use for this purpose troops which will not weaken his main army so much
as the withdrawal of his good troops.

These reserves ought to hold the most important points between the base
and front of operations, occupy the fortified places if any have been
reduced, observe or invest those which are held by the enemy; and if
there be no fortress as a point of support, they should throw up
intrenched camps or _tetes de ponts_ to protect the depots and to
increase the strength of their positions.

All that has been said upon pivots of operations is applicable to
temporary bases and to strategic reserves, which will be doubly valuable
if they possess such well-located piv