_Attacking a Vessel in Motion from Right Ahead._--In this case two torpedoes are launched, port and starboard, each diverging to its full extent; when passing the vessel attacked, one or the other of the tow ropes is brought across the cut-water, and by the simultaneous motion of the two vessels in opposite directions, the torpedo is brought alongside of or under the bottom of the vessel attacked, as shown at Fig. 114. The torpedo vessel should keep the masts of her enemy in one until close to, when either torpedo will be used, according to the movement of the enemy. At the time of the tow rope taking the cut-water, the brake is suddenly eased up; the tow rope will then pass under the bottom, when by checking the tow rope the torpedo will be hauled under the bottom. To execute this attack, judgment, skill, and nerve of the highest order will be required, as the risk of being run down will be imminent. _The Attack from Astern._--In this case two torpedoes are launched, and diverged as in the previous case; it is assumed in this instance that the torpedo vessel can outspeed the vessel attacked, which will enable her to bring a torpedo under the run of the attacked vessel, as shown at Fig. 115. [Illustration: SYSTEMS OF ATTACK WITH HARVEY'S TOWING TORPEDO. PLATE XXXIII] [Illustration: SYSTEMS OF ATTACK WITH HARVEY'S TOWING TORPEDO. PLATE XXXIV] _If Chased by a Hostile Vessel, and unable to Face her._--In this case veer a torpedo astern, having first obtained a position a little on the bow of the chasing vessel. When it is known by the length of the tow rope out that the torpedo is about abreast of her bow, hold fast the tow rope, which will cause the torpedo to diverge, and be brought into contact, as shown at Fig. 116. As a last resort drop spanned torpedoes. Torpedoes can be used with a stern board, if necessary. The port torpedo, in this case, will be launched on the starboard side, and the starboard on the port side. It should be here remarked that, although great speed is essential in the torpedo vessel to come up with the enemy and choose an advantageous position, it is not advisable to tow the torpedoes, if it can be avoided, at a greater speed than 11 knots; because the strain brought upon the towing gear is excessive, and the torpedo would require a large addition of ballast to keep it sufficiently immersed to attain the full divergence. There is, however, one style of attack in which the highest speed can be maintained, viz. by dropping the torpedo alongside in passing. This mode of attack is one of the best, particularly under cover of darkness, against a ship at anchor.