he garrison to an extent that exercised an appreciable effect
upon the fire of Jackson during the passage.

While the bombardment was progressing, the lighter vessels of the
squadron were continuously engaged by detachments in protecting the
mortar flotilla, steaming up above it and drawing upon themselves the
fire of the forts. A more important duty was the removal of the
obstructions that the enemy had thrown across the river, below the
works, but under their fire. Opinions differed, both in the United
States squadron and in the counsels of the enemy, as to the power of the
ships to pass the forts; but it was realized on both sides that any
barrier to their passage which should force them to stop under fire, or
should throw confusion into their order, would materially increase the
chances against them. Whatever the blindness or neglect of the
Confederate Government, the Confederate officers of the department had
not been remiss in this matter. The construction of a floating barrier
had early engaged their attention, and, despite the difficulties
presented by so rapid a current, a formidable raft had been placed early
in the winter. It consisted of cypress logs forty feet long and four or
five feet in diameter, lying lengthwise in the river, with an interval
of three feet between them to allow drift to pass. The logs were
connected by two and a half inch iron cables, stretching underneath from
one side of the stream to the other; and the whole fabric was held up
against the current by some thirty heavy anchors and cables. So long as
it stood, this constituted a very grave difficulty for an attacking
fleet; but the water was deep and the holding ground poor, so that even
under average conditions there was reason to fear its giving way. The
fleet arrived in the early spring, the season when the current, swollen
by the melting snows about the head waters of the Mississippi and its
tributaries, is at its strongest; and in 1862 the spring rise was
greater than for many years. In February the raft began to show signs of
yielding under the pressure of the drift wood accumulating on it from
above, and on the 10th of March the cables had parted, the sections on
either side being swept against the banks and leaving about a third of
the river open. The gap was filled by anchoring in it eight heavy
schooners of about two hundred tons burden. They were joined together as
the cypress logs had been, but with lighter chains, probably b