James Russell Soley, Professor U. S. Navy, Confederate Military History, a library of Confederate States Military History: Volume 7.1, The blockade and the cruisers
Clement Anselm Evans, Ed.

In regard to the ram, though seemingly a paradox, it may be said that its employment in naval warfare was so ancient that in 1861 it was really a new weapon. Its revival was a direct consequence of the application of steam to the propulsion of vessels. The Greeks and Romans had used it in their galley-fights with destructive effect; and it was only displaced by heavy guns when oars were displaced by sails, when ships no longer fought end-on, but broadside to broadside, and when the close-hauled line ahead took the place of the direct attack in line abreast, of the old galley tactics. The introduction of steam, by giving ships-of-war a motive power under their own control, independent of the action of the wind—an advantage similar to that which the triremes possessed in their banks of oars—revived the trireme's mode of attack, and made the ram once more an effective weapon. But in 1861 this phase of naval development had not been recognized, and the sinking of the Cumberland, in March of the next year, first revealed the addition that steam had made to the number and variety of implements of destruction.

Torpedoes, though of more recent introduction than rams, were not wholly new weapons. The idea of the torpedo, first discovered by Bushnell, and developed by Fulton, was rejected by the English Government in 1805, because it was recognized as giving an advantage to a weak navy over a powerful one, and its adoption could only impair the maritime supremacy of Great Britain. On account of this advantage which the torpedo gave to the weaker side, it was brought into use by the Russians in the Crimea, and, though none of the allied vessels were destroyed by its agency, it none the less contributed appreciably to the protection of Russian harbors. But its great importance was not established