=The Spar Fittings.= (_Plate XII._)—The most approved method of fitting a torpedo spar with guys and topping lift is shown in the plate. Spans are fitted to the spar on which the forward guy and topping lift travel freely, and these spans are rove through lizards to divide the strain along the spar and prevent vibrations. The forward guy should be single, with as much drift as possible, and long enough to let the spar trail aft, after the explosion. The forward guy, the pendant of the topping lift, or that part of it secured to the span, the spans and lizards should be of galvanized-iron wire rope, ⅝ inch in diameter. The after guy may be a single part of small manilla rope, say 3-inch. The forward guy should be led from as near the water-line as possible to keep the spar from rising. CHAPTER II. PREPARATION OF TORPEDOES. SERVICE TORPEDO. =Pattern D.—Plate I.= =Priming the Service Torpedo.=—Take the torpedo out of its box; remove the screw-cover of the case and take out the wet gun-cotton found in the primer-case; wipe the primer-case dry and insert a primer of 16 one-half inch blocks, or 4 two-inch blocks of dry gun-cotton. The wet gun-cotton removed from the primer-case is to be put in one of the empty exercise torpedo-cases and dried when opportunity offers. Wipe the screw-thread carefully and screw down tight the cover on its washer, taking care not to cut it, using the open-end wrench provided for the purpose in the supply-box. _It is absolutely necessary that this case be closed water-tight._ =_Note._=—It is not advisable to prime torpedoes for a much longer time before using than the exigencies of the service require, although experiments at the Torpedo Station show that service gun-cotton torpedoes may remain primed for three months, under service conditions, and yet be relied upon to explode. =Testing the Detonator.=—Select a detonator, brighten the ends of its legs and attach them to leading-wires. _Put the detonator in a safe place_, connect the leading-wires to the terminals of the testing-magneto and turn the crank. Rattling of the armature will indicate continuity of the circuit and is presumptive evidence that the detonator is good. The wires from the detonator can be taken to the binding-posts T, T of the firing-key of the A machine and tested, a deflection of the needle furnishing proof of continuity (_Plate XVI_); or they can be taken to the terminals of the C machine which will indicate continuity by the striking of its gong. (_Plate XVI_).