army by
detachments, are intrusted to the care of raw and militia forces." It is
not supposed that any system of fortifications can hermetically close a
frontier; "but, although they of themselves can rarely present an
absolute obstacle to the advance of the hostile army, yet it is
indisputable that they straiten its movements, change the direction of
its marches, and force it into detachments; while, on the contrary, they
afford all the opposite advantages to the defensive army; they protect
its marches, favor its debouches, cover its magazines, its flanks, and
its movements, and finally furnish it with a place of refuge in time of
need."

These opinions were uttered, be it remembered, long since the period at
which modern military quacks date the downfall of fortifications as
inland defences, by men, too, who were not engineers, and consequently
had no professional predilections in favor of fortifications. The
Archduke Charles, as a general, knew no rival but Napoleon, and General
Jomini is universally regarded as the first military historian of the
age. The truth of their remarks on fortifications is most fully
confirmed by the military histories of Germany and France.

For a long period previous to the Thirty Years' War, its strong castles
and fortified cities secured the German empire from attacks from abroad,
except on its extensive frontier, which was frequently assailed, but no
enemy was able to penetrate to the interior till a want of union among
its own princes opened its strongholds to the Swedish conqueror; nor
then, did the cautious Gustavus Adolphus venture far into its
territories till he had obtained possession of all the military works
that might endanger his retreat.

Again, in the Seven Years' War, when the French neglected to secure
their foothold in Germany, by placing in a state of defence the
fortifications that fell into their power, the first defeat rendered
their ground untenable, and threw them from the Elbe back upon the Rhine
and the Mayne. They afterwards took the precaution to fortify their
positions, and to secure their magazines under shelter of strong places,
and, consequently, were enabled to maintain themselves in the hostile
country till the end of the war, notwithstanding the inefficiency of
their generals, the great reverses they sustained in the field, the
skill and perseverance of the enemy they were contending with, and the
weak and vacillating character of the cabinet that