retching from one side of the river to the other. To give
the framework of trunks greater rigidity, large timbers, six by four
inches, were pinned down on the upper sides. The cables were secured
on the left bank to trees; on the right bank, where there were no
trees, to great anchors buried in the ground. Between the two ends the
raft was held up against the current by twenty-five or thirty
3,000-pound anchors, with sixty fathoms of chain on each. This raft,
placed early in the winter, showed signs of giving in February, when
the spring-floods came sweeping enormous masses of drift upon it, and
by the 10th of March the cables had snapped, leaving about a third of
the river open. Colonel Higgins was then directed to restore it. He
found it had broken from both sides, and attempted to replace it by
sections, but the current, then running four knots an hour, made it
impossible to hold so heavy a structure in a depth of one hundred and
thirty feet and in a bottom of shifting sand, which gave no sufficient
holding ground for the anchors. Seven or eight heavily built
schooners, of about two hundred tons, were then seized and placed in a
line across the river in the position of the raft. Each schooner lay
with two anchors down and sixty fathoms of cable on each; the masts
were unstepped and, with the rigging, allowed to drift astern to foul
the screws of vessels attempting to pass. Two or three 1-inch chains
were stretched across from schooner to schooner, and from them to
sections of the old raft remaining near either shore.

Such was the general character of the obstructions before the fleet.
The current, and collisions with their own vessels, had somewhat
disarranged the apparatus, but it was essentially in this condition
when the bombardment began. It was formidable, not on account of its
intrinsic strength, but because of the swift current down and the
slowness of the ships below, which, together, would prevent them from
striking it a blow of sufficient power to break through. If they
failed thus to force their way they would be held under the fire of
the forts, powerless to advance.

It is believed that, in a discussion about removing the obstructions,
Lieutenant Caldwell, commanding the Itasca, volunteered to attempt it
with another vessel, and suggested taking out the masts of the two.
The Itasca and the Pinola, Lieutenant-Commanding Crosby, were assigned
to the duty, and Fleet-Captain Bell given command of both; a r