feet, and at the point just above the lower chute,
where Bailey proposed to construct his dam, the river was 758 feet
wide, with a fall of six feet below the dam. The problem was how
to raise the water above the dam seven feet, backing it up so as
to float the gunboats over the upper rapids.

Heavy details were made from the troops, the working parties were
carefully selected, and on the 30th of April the work was begun.
From the north bank a wing-dam was constructed of large trees, the
butts tied by cross logs, the tops laid towards the current, covered
with brush, and weighted, to keep them in place, with stone and
brick obtained by tearing down the buildings in the neighborhood.
On the south bank, where large trees were scarce, a crib was made
of logs and timbers filled in with stone and with bricks and heavy
pieces of machinery taken from the neighboring sugar-houses and
cotton-gins. When this was done there remained an open space of
about one hundred and fifty feet between the wings, through which
the rising waters poured with great velocity. This gap was nearly
closed by sinking across it four of the large Mississippi coal-barges
belonging to the navy.

When on the 8th of May all was thus complete, the water was found
to have risen five feet four and a half inches at the upper fall,
giving a measured depth there of eight feet eight and one half
inches. Three of the light-draught gunboats, _Osage, Neosho_, and
_Fort Hindman_, which had steam up, took prompt advantage of the
rise to pass the upper fall, and soon lay in safety in the pool
formed by the dam; yet for some reason the other boats of the fleet
were not ready, and thus in the very hour when safety was apparently
within their reach, suddenly they were once more exposed to a danger
even greater than before. Early on the morning of the 9th the
tremendous pressure of pent-up waters surging against the dam drove
out two of the barges, making a gap sixty-six feet wide, and swung
them furiously against the rocks below. Through the gap the river
rushed in a roaring torrent. At sight and sound of this, the
Admiral at once mounted a horse, galloped to the upper fall, and
called out to the _Lexington_ to run the rapids. Instantly the
_Lexington_ was under way, and as, with a full head of steam she
made the plunge, every man in the army and the fleet held his breath
in the terrible silence of suspense. For a moment she seemed lost
as she reeled and almost