My own experiments, Captain Maury says, show that the electrical torpedo, or mine has not hitherto been properly appreciated as a means of defence in war. It is as effective for the defence as ironclads and rifled guns are for the attack. Indeed, such is the progress made in what may be called this new Department of Military Engineering that I feel justified in the opinion that hereafter in all plans for coast, harbour and river defences and in all works for the protection of cities and places whether against attacks by armies on land or ships afloat, the electrical torpedo is to play an important part. It will not only modify and strengthen existing plans, but greatly reduce the expense of future systems. These experiments have resulted in some important improvements and contrivances, not to say inventions and discoveries which as yet have been made known only to the Confederate Government. They are chiefly as follows: First. A plan for determining by cross bearing when the enemy is in the field of destruction, and for "making connections" among the torpedo wires in a certain way and by which (the concurrence of two operators) becomes necessary for the explosion of any one or more torpedoes. This plan requires each operator to be so placed, or stationed that a line drawn straight from them to the place of the torpedoes may intersect as nearly as practicable at right angles, and it requires the connections to be such that each operator may put his station in or out of circuit at will. When the torpedoes are laid, a range from each station is established for every torpedo or group of torpedoes. When either operator observes an enemy in range with any torpedo he closes his circuit for that torpedo. If the enemy before getting out of this range should enter the range for any torpedo from the other station the operator then closes his circuit, and discharges the igniting spark. Consequently if the range belongs to the same torpedo its explosion takes place. But if not there will be no explosion; hence, here is an artifice by which explosion becomes impossible when the enemy is not within the field of destruction, and sure when she is. Second. The "Electrical Gauge," a contrivance of my own, by means of which one of the tests which the igniting fuse has to undergo before it is accepted, is applied. By means of it the operators can telegraph through the fuse to each other without risk to the torpedoes, and by which the torpedoes, may without detriment to their explosibility be tested daily, or as often as required. And thus the operator can at all times make sure that all is right. Third. A plan for planting torpedoes where the water is too deep for them to lie on the bottom and explode with effect, by which they will not interfere with the navigation of the channel, and by which when the enemy makes his appearance they may, by the touch of a key be brought instantly into the required position and at the proper depth.