The safety-break consists of two round, tapering pieces of brass each fitted with a score and two small holes in the smaller end to which the leading-wire is permanently secured. The larger ends, fitted to ship together bayonet fashion, can be readily connected or disconnected at pleasure. Directions for using these wires are given in “Preparation of Contact Torpedo.” SPAR-BANDS. =Plate IV.= These, of wrought iron, furnish a ready means of securing secondary spars to the ordinary wooden torpedo-spars supplied to ships. These bands, with loops on top, are secured to the end of the wood spar, 3 feet apart, with wood screws. The inner band has a key-way, to hold the secondary spar in place. Care must be taken that the loops of both bands are exactly in line. SUPPLY-BOX. This box, containing tools and small articles required in spar-torpedo work, is marked on top, “Torpedo Supply-Box.” For contents see Box 3 “List of Articles in Outfit supplied from Torpedo Station.” BOAT-FITTINGS. =Pattern B.—Plate VI.= These, for the support and handling of the boat spars, consist of bow-fittings, 2 swivel-crutches and 2 heel-rests. The heel-rest is an iron crutch bolted to the rail well aft. A hinge allows the rest to be laid inboard when not in use. The swivel-crutch is a square iron collar fitted with a shank that turns freely in a bearing firmly bolted to the rail, 9 feet abaft the cross-beam. The collar is made in two parts, the upper one working on a hinge, and has two rollers. Bow-fittings consist of a cross-beam with its attachments. The cross-beam, made of heavy wrought-iron tubing, is secured across the bow to castings let into the rail. On sleeves, at the ends of the cross-beam, are elevating-arms free to revolve in a vertical plane. At the outer end of each arm a swivelled guide-ring is placed, projecting at right angles to the arm in the direction of the beam of the boat. In the lower part of this ring is a roller. Connected with the sleeve of each arm is a gear moved by a worm on the forward end of a shaft extending aft into the boat, an elevating-wheel being keyed to the after end of the shaft. The worm-shaft is in two lengths joined by a hook-coupling interposed near the forward end of the shaft to allow the worm sufficient play to engage the gear of the elevating-arm during the revolution of the shaft. The worm-shaft is allowed a fore-and-aft motion such that, when the shaft is forward, the worm is disengaged from the gear of the elevating-arm, leaving it unsupported and free to drop and, when the shaft is aft, the worm is engaged with the gear so that the elevating-arm may be controlled by the elevating-wheel.