She was
compared to a "cheesebox on a raft"; she was named the _Monitor_, and
was the parent of a type of vessel so called which has been heard of
much more recently. The _Merrimac_ and the _Monitor_ forthwith fought
a three hours' duel; then each retired into harbour without fatal
damage. But the _Merrimac_ never came out again; she was destroyed by
the Confederates when McClellan had advanced some way up the Peninsula;
and it will be unnecessary to speak of the several similar efforts of
the South, which nearly but not quite achieved very important successes
later.

Before and after his arrival at the Peninsula, McClellan received
several mortifications. Immediately after the humiliation of the
enemy's escape from Manassas, he was without warning relieved of his
command as General-in-Chief. This would in any case have followed
naturally upon his expedition away from Washington; it was in public
put on that ground alone; and he took it well. He had been urged to
appoint corps commanders, for so large a force as his could not remain
organised only in divisions; he preferred to wait till he had made
trial of the generals under him; Lincoln would not have this delay, and
appointed corps commanders chosen by himself because he believed them
to be fighting men. The manner in which these and some other
preparatory steps were taken were, without a doubt, intended to make
McClellan feel the whip. They mark a departure, not quite happy at
first, from Lincoln's formerly too gentle manner. A worse shock to
McClellan followed. The President had been emphatic in his orders that
a sufficient force should be left to make Washington safe, and supposed
that he had come to a precise understanding on this point. He suddenly
discovered that McClellan, who had now left for Fort Monroe, had
ordered McDowell to follow him with a force so large that it would not
leave the required number behind. Lincoln immediately ordered McDowell
and his whole corps to remain, though he subsequently sent a part of it
to McClellan. McClellan's story later gives reason for thinking that
he had intended no deception; but if so, he had expressed himself with
unpardonable vagueness, and he had not in fact left Washington secure.
Now and throughout this campaign Lincoln took the line that Washington
must be kept safe--safe in the judgment of all the best military
authorities available.

McClellan's progress up the Peninsula was slow. He had not