_Every Species of Torpedo used--Frame Torpedoes at Charleston, &c.--Federal Ship Disasters--Small Effect of Electrical Mines--Loss of the "Commodore Jones," &c._--Every species of submarine mine seems to have been used by the Southerners for their harbour and river defence, the most effectual of which were the barrel, frame, and Singer's torpedoes. These were all mechanical, fired by means of sensitive concussion fuzes. At Charleston and elsewhere the frame torpedo, which also acted as an obstruction, was largely used, and where this species of mine was known to be laid, the Northerners never attempted to force a passage. Out of some thirty or forty Federal ships sunk or injured by torpedoes, by far the larger proportion of such disasters was effected by means of the barrel and Singer's mines. Though electrical mines were very extensively used on the St. James River and at Charleston, &c., yet only one Federal steamer, the _Commodore Jones_, was sunk, and only one other, the _Commodore Barney_, was injured. _Case of the "New Ironsides."_--The Federal ship _New Ironsides_, at the attack on Charleston in 1863, was anchored for one hour and a half exactly over a 5000 lbs. electrical mine, which despite all the efforts of the Confederates could not be exploded. The reason of this was owing to the deterioration of the primer, due to too constant testing. _Welden Railway._--A notable instance of the effect of torpedoes on the war was the saving of the Welden line of communication in December, 1864. The Welden Railway was the principal artery of communication to Richmond for the Confederates. To intercept this, by destroying the railway bridges, a fleet of nine Federal gunboats was sent up the Roanoke river; when nearly arrived at their destination, and though every precaution in the shape of bow projecting spars, creeping, &c., was taken, seven of the vessels were either sunk or severely injured by submarine mines. Thus the expedition ended in a most disastrous failure. _General Butler's Attack on Richmond._--Again, in April, 1864, General Butler's attack on Richmond utterly failed, owing to the Federal fleet being unable to co-operate with him, the destruction of the _Commodore Jones_ completely checking any further advance of Admiral Lee's ships, thus allowing the Confederates to employ the garrisons of their river batteries in their land line of entrenchments. _More than One Line of Torpedoes required._--The capture of the Spanish fort at Mobile in April, 1865, by a Federal fleet under Admiral Lee, proves the necessity of employing more than one line of torpedoes, where the safety of a position depends almost entirely on those means of defence, as this one did. Here, though several Federal vessels were either sunk or severely damaged, yet the fort was captured. _Boat Torpedo Attacks._--In regard to boat torpedo attacks, the Confederates were only successful in two out of many attempts made by them to sink Federal vessels.