of the Allies at Sebastopol, the greatest
siege of modern times.

But these batteries, with a single exception, never spoke. Like their
predecessors around Washington, they conquered by their mere presence.
After all the skill and labor that had been bestowed on their
construction, the enemy evacuated Yorktown just as our batteries were
about to open. He was at our mercy. General Barnard says that "the
enemy's position had become untenable,--that he could not have endured
our fire for six hours." We can readily understand how mortifying it
must have been to the Commanding General, and particularly to the
officers of engineers and artillery who had planned, built, and armed
these siege-works, to hear that the enemy had evacuated his
fortifications just at the moment when we were prepared to drive him
from them by force; and we can appreciate the regrets of General
Barnard, when he says, in reviewing the campaign, and pointing out the
mistakes that had been committed, that "we should have opened our
batteries on the place as fast as they were completed. The effect on the
troops would have been inspiring. It would have lightened the siege and
shortened our labors; and, besides, we would have had the credit of
driving the enemy from Yorktown by force of arms; whereas, as it was, we
only induced him to evacuate for prudential considerations." And General
Barry says, in his report of the artillery operations at the siege,--"It
will always be a source of great professional disappointment to me, that
the enemy, by his premature and hasty abandonment of his defensive line,
deprived the artillery of the Army of the Potomac of the opportunity of
exhibiting the superior power and efficiency of the unusually heavy
metal used in this siege, and of reaping the honor and just reward of
their unceasing labors, day and night, for nearly one month."

The next serious obstacle to be overcome, after the siege of Yorktown,
was the passage of the Chickahominy. Here, says General Barnard, "if
possible, the responsibility and labor of the engineer officers were
increased." The difficulties of that river, considered as a military
obstacle, are given in a few touches; but in the sketch of the opposing
heights, and of the intermediate valley, filled up with the stream, the
heavily timbered swamp, and the overflowed bottom-lands, we have the
Chickahominy brought before us so vividly that we can almost _feel_ the
difficulty of crossing it. Well ma