The drawing shows a small brake fitted for the electric torpedo, having a hollow central spindle, through which the end of the tow-rope carrying the insulated wire is rove, after passing out at the axle; a swivel connection is made with the battery. The brakes, both large and small, are so made as to ensure durability, they being considered a part of the ship’s furniture. Brake for safety-key line is a small reel on the same principle. When going a slow speed, it may not be necessary, as the safety-key line can be attended by hand; but when going ten or eleven knots, it will be found of considerable advantage, both in keeping the light of the safety-key line from dragging astern, thereby lessening the divergence of the torpedo, and also in drawing the safety key when a strong stop is used. The ordinary deep-sea lead line can be used for a safety-key line, or any hemp-rope from three-quarters to an inch circumference. It should be new and of good quality; for in the event of its carrying away before the stop, it would necessitate the recovery of the torpedo. [Illustration: DRAWING 3.] [Illustration: (Y)] The magazine for exploding bolts is fitted with exactly the same size brass tubing as in the priming case; therefore, if the bolts are kept to work with the proper pressure when in the magazine, they will do so in the torpedo. This magazine should be kept apart from the torpedo-room, and care should be taken that the tube is clear before forcing the loaded bolt into it. The torpedoes are then no more dangerous than any other powder case, and, being very strongly made and sealed, are probably less so. [Illustration: Plate 2. Kell Bros. Lith. London.] ARRANGEMENTS REQUIRED FOR LAUNCHING AND TOWING. A yard across either the main or mizen mast of a torpedo vessel, from ten to fifteen feet above the water-line, is a very convenient method for launching and towing. The leading block on the yard, through which the tow-rope is rove, may be fitted to a traveller on the yard with an inhaul and outhaul, that the distance out from the ship’s side may be regulated as convenient. In a large vessel, the leading block for tow-rope can be fixed to the end of the quarter-boat’s davits. The brakes for commanding the tow-rope should be screwed firmly to the deck. In a vessel properly constructed for the service, they would be on the lower deck, the tow-rope having been led along the yard, and down each side of the mast.