fortifications do not now usually sustain a siege of as _many days_ as
in former times, still, as compared with the relative lengths of
campaigns in ancient and modern wars, the _proportional_ length of
sieges is now even _greater_ than formerly. When the same is
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.