To obtain insulated wire, of which the South had none, an agent was sent secretly to New York, but without success, and as there was neither factory nor material for its manufacture in the Confederacy, the difficulties of preparing electrical torpedoes, to which Captain Maury attached the most importance and greatly preferred, seemed insuperable, until by a remarkable piece of good fortune, in the following spring, it happened that the enemy, attempting to lay across Chesapeake Bay were forced to abandon the attempt and left their wire to the mercy of the waves, which cast it upon the beach near Norfolk, where, by the kindness of a friend, it was secured for Captain Maury's use. With part of this he connected his mines in James River, below the obstructions, with the shore stations, which afterward destroyed the "Commodore Barney," and later the "Commodore Jones," and with part enabled other Southern ports to be similarly protected. Of his James River torpedoes, Captain Maury thus reported to the Secretary of the Navy: Richmond, June 19th, 1862. Sir,--The James River is mined with fifteen tanks below the Iron Battery at Chaffin's Bluff. They are to be exploded by means of Electricity. Four of the tanks contain 160 pounds of powder, the eleven other hold 70 pounds. All are made of boiler plate. They are arranged in rows, as per diagram, those of each row being thirty feet apart. Each tank is contained in a water-tight wooden cask, capable of floating it, but anchored, and held below the surface from three to eight feet, according to the state of the tide. The anchor to each is an eighteen inch shell and a piece of kentledge so placed as to prevent the barrels from fouling the buoy ropes at the change of the tide. Each shell of a row is connected with the next one to it by a stout rope thirty feet long, and capable of lifting it in case the cask be carried away. The casks are water-tight, as are also the tanks, the electric cord entering and returning through the same head. The wire for the return current from the battery is passed from shell to shell and along the connecting rope, which lies at the bottom. The wire that passes from cask to cask is stopped aslack to the buoy rope from the shell up to the cask to which it is securely seized, to prevent any strain upon that part which enters the cask. The return wire is stopped in like manner down the buoy ropes to the shell, and then along the span to the next shell. At 4 the two cords are rapped together, loaded with trace chains a fathom apart and carried ashore to the galvanic battery. For batteries we have 21 Wollastons, each trough containing 18 pairs of plates, zinc and wire, 10 x 12 inches. The first range is called 1: the second 2: the third 3, and the wires are so labelled. Thus all of each range are exploded at once.