The buoys are made of solid cork (such cork only being used as will ensure great floating power after being immersed for a time), it is built up on a galvanized iron tube, running longitudinally through; on the ends of the tube are screwed wooden cones, which bind all together and render the buoy indestructible. The iron tube gives great facility for stringing on the number of buoys required. [Illustration: DRAWING (W). SECTION ON A B.] Two buoys are generally used for the large torpedo, and one for the small. The buoy-rope is of hemp, about five or six fathoms in length and two inches circumference, an eye being spliced in the end nearest the torpedo; to this eye is bent the tow-rope with a single or double sheet bend, forming the knot by which the torpedo is towed; the other end of the buoy-rope is passed through the large or small ring in the stern (according to whether working in deep or shallow water), then through the tube of the first buoy, an overhand knot made in the rear; then through the next buoy, and a knot in the rear of that. [Illustration: DRAWING (X).] [Illustration: DRAWING 1.] The brakes are used for the purpose of controlling the tow-ropes; they can be fixed by screws into the deck at the most convenient place for command, and, in a properly-constructed vessel, would be worked below the water-line to prevent exposure of the men. They are so arranged as to admit of the tow-rope being quickly veered, and at the same time powerful in bringing the torpedo to the surface when required. Success greatly depends on the skilful handling of these brakes, for in conjunction with the cork buoys they give the operator command of the depth at which the enemy is to be struck. The handles on the leather straps are for the purpose of lifting the strap off the drum when veering suddenly, that there may be no friction to interfere. The handles for winding up would rarely be used in real action, and never should be on when veering. Unless a very high rate of speed is required, one handspike will control the tow-rope; the other strap can be thrown off the drum, and the handspike allowed to lie on the deck ready to be thrown into gear, if necessary. The surface of the drum in contact with the strap should be powdered with rosin to increase the friction. The tow-rope should be so reeled up, that in veering the reel may revolve towards the men at the handspike (see Plate 2). The spindle will contain several tow-ropes, that, in the event of one torpedo being cut away, another can be immediately bent. The brake for small torpedo requires only one drum and handspike. It can be fitted to a steam-launch by placing an extra thwart across near one of the others. [Illustration: DRAWING 2.]