The torpedo must be closing to the ship when the levers are acting and the bolt descending; no experiment for the force of explosive agents, with a cushion of water intervening, is required. The amount of explosive agent, when in contact, is all that is required, and the torpedo can be manufactured to contain a larger charge, if thought necessary, with a very small increase of dimensions; but the present size is convenient for handling and launching; and if loaded with any of the powerful blasting powders, would, in all probability, prove sufficient to bilge or destroy the largest iron-clad. [Illustration: (M)] [Illustration: (N)] The lanyard or side-lever is permanently secured to the short arm of the lever; the end is rove under the fair lead on the deck of the torpedo up through the brass oval hole in the after top lever, then down under the fair lead (abaft the first turn), and across the deck of the torpedo to the handle, and secured with a round turn and two half-hitches. Care should be taken that the short arm of the lever is brought close into the fair lead, and the lanyard should be set up sufficiently taut to give a slight spring in the after top lever by the strain brought on it. This lever has a steel fish on the top, in order to prevent it taking a permanent bend. If the side-lever lanyard is properly set up, the bolt will spring down about one-eighth of an inch when the safety key is withdrawn, owing to the spring in the lever and shrinking of the lanyard; this brings the muzzle one-eighth of an inch nearer the pin without disturbing the side lever. The lanyard should be made up like a reef-point; it should be well-greased immediately before launching. [Illustration: (O)] [Illustration: (P)] [Illustration: (Q)] To secure the fore top lever to the after, in order that a back hit may not separate them, the small lanyards, with an eye in one end, and whipped at the other, are first placed over the eyes in the fore top lever, then rove through the brass hole in the after top lever, in opposite directions, passed up through the eyes in the fore top lever, and knotted over it. The distance from the eyes in the fore top lever to the hole in the after top lever is so arranged that it will not interfere with the descent of them. The fore-locks for the various bolts which fix the levers are made of fishing-line. After knotting them, the ends should be secured together by a seizing of thread. [Illustration: (R)] [Illustration: (S)] The handles, formed of iron straps passing under the torpedo, and terminating in four eyes above the deck, are principally for handling it; one of the foremost eyes is made use of as a fair lead for the safety-key lanyard, and to stop it to; the other foremost is made use of to secure the side lanyard to Fig. N (p. 12).