In the more early stage of the torpedo, the tactics of vessels armed with torpedoes embraced modes of attack that are not now entertained. So general is becoming the use of torpedoes as a means both of defence and offence, that vessels, which may be at anchor or moored in a harbour or roadstead, would be protected by stationary torpedoes; the use of which admits also of vessels, when at anchor or moored, protecting themselves by placing a web of torpedoes in such manner as to render the attack of a hostile vessel or boats extremely hazardous, and therefore not likely to be attempted. But in the event of a vessel being at anchor in a harbour or roadstead unprotected, she could be attacked, as shown in the illustration of Tactics, under such conditions. As, however, vessels armed with torpedoes are intended to work the arm against vessels at sea or in motion, the management of the torpedo in so attacking vessels is the more important part of the code of Tactics. It should be here remarked, that with a view to simplicity, the explanations will be confined to a single steamer, the attacking vessel adapted to the service of the arm in question, and confined also to a single vessel, the object of attack. CASE 1. ATTACKING A VESSEL MOORED HEAD AND STERN. In this case the torpedo vessel steers in for the bow or quarter of the vessel attacked, according to the direction of the current, and on the side approached launches the torpedo between the moorings as at A; leaving the tow-rope slack, the torpedo vessel proceeds ahead or astern against the current, and when at a sufficient distance off, the tow-rope is held fast, which will cause the torpedo to diverge into contact with the vessel attacked, as shown by the drawing. [Illustration: Plate 4. Kell Bros. Lith. London. CASE 1.—ATTACKING A VESSEL MOORED HEAD AND STERN.] CASE 2. ATTACKING A VESSEL AT ANCHOR BY CROSSING THE BOW. In this case, the torpedo is sufficiently diverged when near to the vessel with a good scope of tow-rope out. After having crossed her bow, proceeding onwards, the tow-rope will be brought obliquely across her cable, and the torpedo will swing into her, as shown in the drawing. It may be here remarked that, in all cases, the depth of explosion can be obtained by the sudden slacking of the tow-rope; and the tow-rope, once under the keel, causes the torpedo to be hauled down near to it before exploding. [Illustration: Plate 5. Kell Bros. Lith. London. CASE 2.—ATTACKING A VESSEL AT ANCHOR BY CROSSING THE BOW.] CASE 3. ATTACKING A VESSEL AT ANCHOR BY PASSING ON EITHER SIDE DETERMINED UPON, COMING UP FROM THE STERN.