While the vessel lay at Cairo, Lieutenant Bryant took advantage of the opportunity to strengthen her pilothouse. His action was based on what had happened to Union gunboats at Fort Donelson (where the Confederates scored damaging hits by centering on the pilothouses, killing and wounding several men, among them Flag Officer Foote, who was struck on the ankle by a piece of iron). Other changes included the addition of timber, iron plating, and flaps. The work was completed by April 10 and Bryant, following orders, set out the next day for Island No. 10. There he joined a fleet of transports, mortar boats, gunboats, and tugs, which moved down the Mississippi several miles and anchored off New Madrid, Mo. The next point of attack would be Fort Pillow, a stronghold guarding the approach to Memphis, but the _Cairo’s_ assignment was to wait behind with the unwieldy mortar scows. By remaining with the mortars, the _Cairo’s_ crew missed the flurry of action that took place with some Confederate boats at Hale’s Point, 50 miles or so below New Madrid, As the Southern craft turned about and fled downstream, the Union fleet followed to within range of the guns at Fort Pillow, then turned about and tied up at Plum Point, a short distance upriver. The _Cairo_ drifted in later with the mortar scows and took station the morning of April 14 to hurl 200-pound shells in a bombardment that would last for 7 weeks. Her guns were trained so as to protect the mortarscows from possible interference by Confederate gunboats. Day after day, sometimes at the rate of one a minute, shells were dropped upon the fort; the Southerners fired back, occasionally scoring hits, but never inflicting serious damage. [Illustration: _The lower Mississippi River and its tributaries, showing the _Cairo’s_ area of operations._] In the meantime, Foote’s wound had become worse and finally reached the stage at which he was forced to retire. On May 9 he turned over command of the Western Flotilla to Capt. Charles H. Davis, a Harvard student who had followed a naval career. (He had been a member of the Office of Detail in Washington at the start of the war and was later stationed with the South Atlantic Blockading Squadron.) That afternoon a Confederate steamer came within range bearing a white flag under the pretense of exchanging two Union surgeons captured at Belmont, Mo. The Federals presumed correctly that the move was one of reconnaissance. The morning after Davis took command, a Confederate fleet of rams steamed up from Fort Pillow just as Mortar Boat No. 16, guarded by the _Cincinnati_, was being moored at Craighead Point to begin the daily bombardment. This move by the Southerners caught the Union ironclads unprepared, some of them without sufficient steam to hold against the current of the stream. But their engineers reacted to the emergency, throwing oil, and anything else flammable which was available to them, into the fireboxes in an effort to raise steam.