Elements of Military Art and Science Or, Course Of Instruction In Strategy, Fortification, Tactics Of Battles, &C.; Embracing The Duties Of Staff, Infantry, Cavalry, Artillery, And Engineers; Adapted online

accomplished in a campaign of seven weeks as was formerly done in a war
of seven years, it is not necessary that fortified places should hold
out a very long time. A place that can sustain a siege of a month is now
deemed sufficiently strong for ordinary campaigns; for by the end of
that time the defensive army will either be destroyed, or be able to
come to its succor. In either case a longer defence would not be
required.

A reference to the most important sieges of the last century or two will
show that forts are, on an average, capable of sustaining a siege for
more than that length of time. Lille, in 1708, held the allies in check
for a whole year; and again, in 1792, compelled the Austrians to raise
the siege after an unsuccessful attack of fifteen days.

Antwerp, in 1585, sustained a siege of fourteen months against greatly
superior forces; in 1814 Carnot defended the citadel of this place for
four months, and until an armistice had been concluded between the
contending parties; in 1832, it sustained, with a garrison of only 4,500
men and 145 pieces of ordnance, a siege of twenty-five days, against a
force of 55,000 men and 223 cannon.

Namur, near the end of the seventeenth century, sustained a siege of ten
weeks.

Ismaïl, in 1790, sustained a siege of more than two months against the
Russians.

Maestricht, in 1793, sustained a siege of nearly two weeks; and again,
in 1794, sustained a blockade and siege of nearly two months.

Magdeburg, in the thirty years' war, resisted the army of Wallenstein
for seven months; and in 1813-14, although garrisoned by only 4,000 men,
it for a long time resisted the overwhelming forces of the allies.

Dantzic, at the same time, sustained a siege against superior forces for
more than nine months.

Landau, in 1793, sustained a siege of nine months.

Valenciennes and Mayence, in 1793, each sustained a siege of about three
months.

Charleroi, Fort Vauban, and L'Ecluse, in 1794, each sustained a siege of
about thirty days.

Quesnoy, in 1794, sustained a siege of about three weeks.

Rosas, in 1795, sustained a siege of some seventy days.

Mantua, in 1796-7, protected from invasion, for eight months, the Tyrol
and the heart of the Austrian monarchy.

Kehl and Huninguen, in 1796, sheltered Moreau for three months against
all the efforts of the Archduke Charles.

St. Jean d'Acre, in 1799, sustained a siege of sixty days of open
trench.

Ulm, in 1800, held Moreau in check for more than a month.

Genoa, in 1800, sustained a blockade of sixty and a siege of forty days.

Saragossa in 1808 sustained a close siege of near two months; and in
1809 it was again besieged for two months.

Rosas in 1808 sustained a siege of thirty days.

Gerona in 1809 sustained a siege and blockade of seven months, nearly
four of them being of open trench.

Mequinenza (a very small work) in 1810 sustained a siege of more than
two weeks.

Astorga in 1810 sustained a siege of thirty days; twenty-four being of
open trench.

Lerida in 1810 sustained a siege of thirty days, two weeks being of open
trench.

Ciudad Rodrigo in 1810 sustained a siege of two months.

Almeida in 1810 sustained a siege of more than a month.

Tortosa in 1810 sustained a siege of six months.

Tarragona in 1811 sustained a siege of nearly two months.

Badajos in 1811 sustained a siege of more than forty days open trench.

Lerida in 1811 sustained a siege of two weeks open trench.

Saguntum in 1811 sustained a siege of a month.

Valencia in 1811-12 sustained a siege of two months

Ciudad Rodrigo in 1812 sustained a blockade of several months, and a
close siege of two weeks.

Badajos in 1812 sustained twenty-one days of open trenches.

Burgos in 1812 sustained thirty-three days of open trenches.

St. Sebastian in 1813 sustained a siege and blockade of nearly three
months, with fifty-nine days of open trenches.

Pampeluna in 1813 sustained a siege of more than four months.

Monzon in 1813-14 also sustained a siege of more than four months.

This list might be increased with numerous other examples, to show that
even poorly fortified towns are capable of defending themselves, on an
average, for more than a month. These examples, be it remembered, are
nearly all taken from a period of history since any material
improvements have been made in the art of attack. Since the time of
Vauban the improvements in attack have not kept pace with the increased
means of defence. Moreover, these examples are taken from the sieges of
towns defended mainly by old and antiquated works, and entirely
incapable of offering the same resistance as detached fortifications,
with all the modern improvements.

The value of fortifications, as land defences, is sufficiently proved by
showing their general capability of resisting an invader, even for a
limited period; thus affording us time and opportunity to provide other
means of security. But it must not be inferred that forts besieged _en
règle_ will necessarily fall after so many days. Such is far from being
the case. The besieged have usually great advantages over the besiegers;
and unless the latter are vastly superior in number, or the work is of a
very inferior character, or the garrison is destitute of the requisite
means and energy to resist an attack, they will not be taken.

Mezieres was not taken in 1520; nor Marseilles in 1524; nor Peronne in
1536; nor Landrecies in 1543; nor Metz in 1552; nor Montauban in 1621;
nor Lerida in 1647; nor Maestricht in 1676; nor Vienna in 1529, and
again in 1683; nor Turin in 1706; nor Conde in 1744; nor Lille in 1792;
nor Landau in 1793; nor Ulm in 1800; nor Saragossa in 1808; nor Burgos
in 1812. This list might be extended almost indefinitely with the names
of places that could be reduced neither by force nor by starvation.

But, as has already been noticed, some have asserted that fortifications
have become of little comparative importance, under the new system of
warfare introduced during the wars of the French Revolution. On this
subject let us consult the opinions of the best military judges of the
present century.

Napoleon says of fortifications, "they are an excellent means of
retarding, fettering, enfeebling, and disquieting a conquering foe."

"The possession of strategic points," says the Archduke Charles, "is
decisive in military operations; and the most efficacious means should,
therefore, be employed to defend points whose preservation is the
country's safeguard. This object is accomplished by fortifications,
inasmuch as they can resist, for a given time, with a small number of
troops, every effort of a much larger force; fortifications should,
therefore, be regarded as the basis of a good system of defence." "It
should be a maxim of state policy in every country, to fortify, in time
of peace, all such points, and to arrange them with great care, so that
they can be defended by a small number of troops. For the enemy, knowing
the difficulty of getting possession of these works, will look twice
before he involves himself in a war." "Establishments which can secure
strategic advantages are not the works of a moment; they require time
and labor. He who has the direction of the military forces of a state,
should, in time of peace, prepare for war." "The proper application or
neglect of these principles will decide the safety or the ruin of the
state." "Fortifications arrest the enemy in the pursuit of his object,
and direct his movements on less important points; - he must either force
these fortified lines, or else hazard enterprises upon lines which offer
only disadvantages. In fine, a country secured by a system of defences
truly strategic, has no cause to fear either the invasion or the yoke of
the enemy; for he can advance to the interior of the country only
through great trouble and ruinous efforts. Of course, lines of
fortifications thus arranged cannot shelter a state against all reverses;
but these reverses will not, in this case, be attended by total ruin;
for they cannot take from the state the means nor the time for
collecting new forces; nor can they ever reduce it to the cruel
alternative of submission or destruction."

"Fortifications," says Jomini, "fulfil two objects of capital
importance, - 1st. The protection of the frontiers; and 2d. Assisting the
operations of the army in the field." "Every part of the frontiers of a
state should be secured by one or two great places of refuge, secondary
places, and even small posts for facilitating the active operations of
the armies. Cities girt with walls and slight ditches may often be of
great utility in the interior of a country, as places of deposit, where
stores, magazines, hospitals, &c., may be sheltered from the incursions
of the enemy's light troops. These works are more especially valuable
where such stores, in order not to weaken the regular 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 directed them.

But this system of defence was not so carefully maintained in the latter
part of the eighteenth century, for at the beginning of the French
Revolution, says Jomini, "Germany had too few fortifications; they were
generally of a poor character, and improperly located." France, on the
contrary, was well fortified: and although without armies, and torn in
pieces by domestic factions, (we here use the language of the Archduke,)
"she sustained herself against all Europe; _and this was because her
government, since the reign of Louis XIII_., _had continually labored to
put her frontiers into a defensive condition agreeably to the principles
of strategy_; starting from such a system for a basis, she subdued every
country on the continent that was not thus fortified; and this reason
alone will explain how her generals sometimes succeeded in destroying an
army, and even an entire state, merely by a strategic success."

This may be illustrated by reference to particular campaigns. In 1792,
when the Duke of Brunswick invaded France, she had no armies competent
to her defence. Their numbers upon paper were somewhat formidable, it is
true, but the license of the Revolution had so loosened the bonds of
discipline as to effect an almost complete disorganization. "It seemed,
at this period," says the historian, "as if the operations of the French
generals were dependent upon the absence of their enemies: the moment
they appeared, the operations were precipitately abandoned." But France
had on her eastern frontier a triple line of good fortresses, although
her miserable soldiery were incapable of properly defending them. The
several works of the first and second lines fell, one after another,
before the slow operations of a Prussian siege, and the Duke of
Brunswick was already advancing upon the third, when Dumourier, with
only twenty-five thousand men, threw himself into this line, and by a
well-conducted war of positions, placing his raw and unsteady forces
behind unassailable intrenchments, succeeded in repelling a disciplined
army nearly four times as numerous as his own. Had no other obstacle
than the French troops been interposed between Paris and the Prussians,
all agree that France must have fallen.

In the campaign, of 1793, the French army in Flanders were beaten in
almost every engagement, and their forces reduced to less than one half
the number of the allies. The French general turned traitor to his
country, and the National Guards deserted their colors and returned to
France. The only hope of the Republicans, at this crisis, was Vauban's
line of Flemish fortresses. These alone saved France. The strongholds of
Lille, Condé, Valenciennes, Quesnoy, Landrecies, &c., held the Austrians
in check till the French could raise new forces and reorganize their
army. "The important breathing-time which the sieges of these
fortresses," says an English historian, "afforded to the French, and the
immense advantage which they derived from the new levies which they
received, and fresh organization which they acquired during that
important period, is a signal proof of the vital importance of
fortresses in contributing to national defence. Napoleon has not
hesitated to ascribe to the three months thus gained the salvation of
France. It is to be constantly recollected that the Republican armies
were then totally unable to keep the field; that behind the frontier
fortresses there was neither a defensive position, nor a corps to
reinforce them; and that if driven from their vicinity, the capital was
taken and the war concluded."

In the following year, 1794, when France had completed her vast
armaments, and, in her turn, had become the invading power, the enemy
had no fortified towns to check the progress of the Republican armies;
which, based on strong works of defence, in a few weeks overran
Flanders, and drove the allies beyond the Rhine.

In the campaign of 1796, when the army of Moreau had been forced into a
precipitate retreat by the admirable strategic operations of the
Archduke Charles, the French forces owed their safety to the
fortifications on the Rhine. These works arrested the enemy's pursuit
and obliged him to resort to the tedious operations of sieges; and the
reduction of the French advanced posts alone, Kehl and Huninguen, poorly
as they were defended, employed all the resources of the Austrian army,
and the skill of their engineers, from early in October till late in
February. Kehl was at first assaulted by a force _four_ times as
numerous as the garrison; if the enemy had succeeded, he would have cut
off Moreau's retreat, and destroyed his army. Fortunately the place was
strong enough to resist all assaults; and Moreau, basing himself on the
fortresses of Alsace, his right covered by Huninguen, Neuf-Brisach, and
Béfort, and his left by the iron barrier of the Netherlands, effectually
checked the waves of Austrian success.

Let us now turn to the campaigns of Napoleon. In his first campaign in
Italy, 1796, the general was directed "to seize the forts of Savona,
compel the senate to furnish him with pecuniary supplies, and to
surrender the keys of Gavi, a fortress perched on the rocky height
commanding the pass of the Bocchetta." Setting out from Savona, he
crossed the mountains at a weak point between the Alps and the
Apennines, and succeeded in piercing the enemy's line of defence. The
king of Sardinia, jealous of Austrian influence, had refused to permit
the Austrian army to garrison his line of fortifications. Napoleon,
profiting by his victorious attitude, the mutual jealousy of Austria
and Sardinia, and the intrigues of his diplomatists, soon gained
possession of these important works. "_These Sardinian fortresses_," he
wrote to the Directory, "_at once put the Republicans in possession of
the keys of the Peninsula_." Basing himself on Coni, Mondovi, Ceva,
Gavi, and Alessandria, with Tortosa as his dépôt of magazines, he
advanced against Lombardy. Now basing himself on the Adda and Po, with
the fortress of Pizzighettone as the dépôt of his magazines, he advanced
upon the line of the Adige. Pechiera became his next dépôt, and he now
had four fortresses in echelon between him and his first dépôt of
magazines; and, after the fall of Mantua, basing himself on the Po, he
advanced against the States of the Church, making Ferrara and then
Ancona, his places of dépôt.

From the solid basis of the fortresses of Piedmont and Lombardy, "he was
enabled to turn his undivided attention to the destruction of the
Austrians, and thus commence, with some security, that great career of
conquest which he already meditated in the imperial dominions." In this
campaign of 1797, after scouring his base, he fortified Palma-Nuova,
Osapo, &c., repaired the old fortifications of Klagenfurth, and, as he
advanced, established, to use his own words, "a good _point d'appui_ at
every five or six marches."

Afterwards, when the Austrians had nearly wrested Italy from the weak
grasp of Napoleon's successors, the French saved their army in the
fortress of Genoa and behind the line of the Var, which had been
fortified with care in 1794-5. Numerous attempts were made to force this
line, the advanced post of Fort Montauban being several times assaulted
by numerous forces. But the Austrian columns recoiled from its murderous
fire of grape and musketry, which swept off great numbers at every
discharge. Again the assault was renewed with a vast superiority of
numbers, and again "the brave men who headed the column almost perished
at the foot of the intrenchment; and, after sustaining a heavy loss,
they were compelled to abandon the enterprise."

While the forces on the Var thus stayed the waves of Austrian success,
Massena, in the fortifications of Genoa, sustained a blockade of sixty,
and a siege of forty days, against an army five times as large as his
own; and when forced to yield to the stern demands of famine, he almost
dictated to the enemy the terms of the treaty. These two defences held
in check the _élite_ of the Austrian forces, while the French reserve
crossed the Alps, seized the important points of the country, and cut
off the Austrian line of retreat. "But even after the victory of
Marengo," says Napoleon, "I did not consider the whole of Italy
reconquered, until all the fortified places between me and the Mincio
should be occupied by my troops. I gave Melas permission to return to
Mantua, on condition of his surrendering all these fortresses."

He now directed Chasseloup de Laubat and his engineers to repair and
remodel the fortifications of Verona, Legnano, Pechiera, Mantua, the
line of the Adda, Milan, Alessandria,[5] Roco d'Aufo, Genoa, and several
smaller works; thus forming a quadruple line of defence against Austrian
aggression in Italy. These works were of great service to the French in
1805, enabling Massena with fifty thousand men to hold in check the
Archduke Charles with more than ninety thousand, while Napoleon's grand
army, starting from the solid base of the Rhine, traversed Germany and
seized upon the capital of Austria.

[Footnote 5: More than twenty millions of money were appropriated for
this place alone.]

The neglect of the Prussians to place their country in a state of
military defence, previous to declaring war against Napoleon in 1806,
had a most disastrous influence upon the campaign. Napoleon, on the
other hand, occupied and secured all the important military positions
which he had captured in the preceding campaign. "The Prussians," said
he, "made no preparations for putting into a state of defence the
fortifications on their first line, not even those within a few marches
of our cantonments. While I was piling up bastion upon bastion at Kehl,
Cassel, and Wesel, they did not plant a single palisade at Magdeburg,
nor put in battery a single cannon at Spandau." The works on the three
great lines of the Oder, the Elbe, and the Weser, had they been properly
repaired, garrisoned, and defended, were sufficient to have held in
check the French, even after the great victory of Jena, till the
newly-organized forces, acting in concert with the Russian army, could
re-establish the Prussian monarchy in its ancient greatness. Profiting
by the neglect of the Prussians, Napoleon seized upon the great
defensive works of the country, which, to his great joy, were readily
surrendered into his hands by the old and inefficient generals who
commanded them; and French garrisons were almost immediately established
in the fortresses of Stettin, Custrin, Glogau, Magdeburg, Spandau,
Hameln, Nieubourg, &c. "Spandau," said he in the 19th Bulletin, "is an
inestimable acquisition. In our hands it could sustain two months of
operations. But such was the general confusion, that the Prussians had
not even armed its batteries." The possession of these fortifications
inclined the scale at Eylau. All the historians of the war notice their
influence on the campaigns of Friedland and Tilsit.

These Prussian fortresses were retained by Napoleon at the treaty of
Tilsit. The campaign of 1809 proved the wisdom of this policy, as they
effectually prevented Prussia from joining Austria in rekindling the
flames of war. And again in 1813, these works might have produced a
decided influence on the campaign, had not the political perfidy of
Austria, and the treason of the French generals, prevented Napoleon from
profiting by the advantages of his position.

The influence of the fortifications of Spain upon the Peninsular
campaigns has often been alluded to by historians. Those works which had
been given up to Napoleon previous to the opening of hostilities,
contributed very much to the success of his arms; while those which had
been retained by Spain and her allies contributed in an equal degree to
fetter and embarrass his operations. Some of these, like Saragossa,
Tarragona, Gerona, Tortosa, &c. &c., with their broken walls and
defective armaments, kept the enemy in check for months; and, by
compelling the French to resort to the tedious operations of sieges, did
much to weaken the French power in the Peninsula.

The influence of the fortifications of the French frontiers in
furnishing a secure basis for the successful operations of Napoleon into
the enemy's territory, has already been noticed. If these fortresses of
France, after the disasters of 1812 and '13, failed to save the nation,
the cause must be sought for in the peculiar features of the invasion
itself, rather than any lack of military influence in the French
defences. As has been already remarked, a million of disciplined men,
under consummate leaders, were here assailing a single state,
impoverished by the fatal war in Russia, - torn in pieces by political
factions, - deserted by its sworn allies, - its fortresses basely betrayed
into the enemy's hands, and its military power paralyzed by the treason
of generals with their entire armies. Its only hope was in the
fortresses which had remained faithful; and Napoleon said at St. Helena,
that if he had collected together the garrisons of these few fortresses
and retired to the Rhine, he could have crushed the allies even after
their entrance into Paris. But political considerations prevented the
operation.

Again in 1815, Napoleon, even after the defeat of Waterloo, possessed