“SIR: I have the honor to inform you that the vessels lately caught by low water above the Falls of Alexandria, have been released from their unpleasant position. The water had fallen so low that I had no hope or expectation of getting the vessels out this season, and, as the army had made arrangements to evacuate the country, I saw nothing before me but the destruction of the best part of the Mississippi squadron. “There seems to have been an especial Providence in providing a man equal to the emergency. Lieutenant-Colonel Bailey, Acting Engineer of the Nineteenth army corps, proposed a plan of building a series of dams across the rocks at the falls, and raising the water high enough to let the vessels pass over. This proposition looked like madness, and the best engineers ridiculed it; but Colonel Bailey was so sanguine of success that I requested to have it done, and he entered heartily into the work. Provisions were short and forage was almost out, and the dam was promised to be finished in ten days or the army would have to leave us. I was doubtful about the time, but I had no doubt about the ultimate success, if time would only permit. General Banks placed at the disposal of Colonel Bailey all the forces he required, consisting of some three thousand men and two or three hundred wagons. All the neighboring steam-mills were torn down for material; two or three regiments of Maine men were set at work felling trees, and on the second day after my arrival in Alexandria, from Grand Ecore, the work had fairly begun. “Trees were falling with great rapidity; teams were moving in all directions, bringing in brick and stone; quarries were opened; flatboats were built to bring stone down from above, and every man seemed to be working with a vigor I have seldom seen equalled, while perhaps not one in fifty believed in the undertaking. These fails are about a mile in length, filled with rugged rocks, over which, at the present stage of water, it seemed to be impossible to make a channel. “The work was commenced by running out from the left bank of the river a tree dam, made of the bodies of very large trees, brush, brick, and stone, cross-tied with heavy timber, and strengthened in every way which ingenuity could devise. This was run out about three hundred feet into the river; four large coal barges were then filled with brick and sunk at the end of it. From the right bank of the river, cribs filled with stone were built out to meet the barges, all of which was successfully accomplished, notwithstanding there was a current running of nine miles an hour, which threatened to sweep every thing before it.