These contrivances are all very simple; they are readily understood from verbal instruction, they require neither models or drawings, and enable the operator chiefly to use the self same wire for testing his torpedoes daily after they are planted, and then to explode them at will. Though these torpedoes, owing to the lack in the Confederacy of the proper materials and appliances for their construction and use, were make-shifts, yet so effective had their use become, especially during the last year of the war, that the Secretary of the American Navy, in his annual report of December, 1865, to the President of the United States, thus testifies to their efficiency: "Torpedoes always formidable in harbours and internal waters, have been more destructive to our naval vessels than all other means combined." Since 1862, finding myself in reach of the facilities afforded in England, I have made the study of Electrical torpedoes a specialty, and the results are such, to say the least, as to show that it is capable of doing quite as much for the defence as ironclads and rifled guns are likely to do for the attack. These results consist in improvements and discoveries which enable the adept in that new department of military engineering to explode his torpedoes whether buried on land or submerged in the water, singly or in groups, instanteously and at any distance to transmit through them without the risk of explosion, orders and commands, and as readily as through the ordinary line of telegraph. To determine with unerring certainty when the enemy is in the field of destruction of this or that torpedo. To render its explosion impossible, unless he be in such field, even though the igniting spark should be discharged; and so to set an electrical current to watch it, as to make the injuring of it without his knowledge impossible, and the removal of it by an enemy, if not impossible, extremely difficult and dangerous. Electrical torpedoes are also available for the defense of mountain passes, roadways and fortified positions on land.