The torpedoes by which the Cairo was sunk were merely demijohns filled with powder and ignited by a common friction primer rigidly secured inside. To the primer was fastened a wire passing through a water-tight cork of gutta percha and plaster of Paris. The first very primitive idea was to explode them by pulling from the shore, and it is possible that the first to go off near the light-draughts was thus fired. The matter was then taken in hand by a Confederate naval officer, who arranged them in pairs, anchored twenty feet apart, the wire leading from the primer of one to that of the other. Torpedoes had hardly yet come to be looked on as a respectable mode of warfare, especially by seamen, and the officer who laid these, and was looking on when the Cairo went down, describes himself as feeling much as a schoolboy might whose practical joke had taken a more serious shape than he expected. The work of removing the torpedoes was continued by the boats under Lieutenant-Commander John G. Walker, of the Baron de Kalb, formerly the St. Louis. Two landing-places were at the same time secured. After the arrival of the admiral the work went on still more vigorously from the 23d to the 26th of December. A bend in the river was then reached, which brought the vessels under fire of the forts on Drumgoold's Bluff. Every step of the ground so far gained had been won under a constant fire of musketry, which the armored portion of the light-draught gunboats resisted, but their upper works were badly cut up. The batteries of the enemy being now only twelve hundred yards off, the flag-ship Benton took position to cover the lighter vessels, having to tie up to the bank because the wind blowing up stream checked the current and threw her across it. She remained in this position for two hours, receiving the enemy's fire and being struck thirty times, but without serious injury. Unfortunately her captain, Lieutenant-Commander William Gwin, a valuable officer, who had distinguished himself at Shiloh and in the fight with the Arkansas, was mortally wounded; having, in his anxiety to see how effective was the fire of the vessels, left the armored pilot-house, saying, with a noble rashness, that the captain's place was on his quarterdeck.