=Testing the Circuit-Closer.=—Remove the water-cap and spherical rubber packing from the side of the circuit-closer; remove its screw-cover; take out the inner plunger. Remove the braid for a few inches from the longer leg (insulated double-conductor cable) at the outer end of the contact spar leading-wires, whipping the braid. Remove the rubber tape from the conductors, and pass them through the water-cap and packing and through the cylinder of the circuit-closer. Remove the insulation for one inch, brighten and lay up the naked wires and connect them to the binding-posts of the circuit-closer, taking care that the bare ends do not project far beyond the binding-posts. Seat the inner plunger, hauling on the wires at the same time, so as not to leave any slack wire in the cylinder. Set down the water-cap on the packing in the side of the circuit-closer. Replace the diaphragm, friction-plate and screw-cover. Remove the insulation for one inch from the shorter legs at the outer end of the leading-wires, and bend the naked wires together temporarily. Connect the inner ends of the leading-wires with the terminals of the testing-magneto, or of the C machine. Close the safety-break. Remove the safety-pin from the circuit-closer and press down the contact-arms. Under these circumstances a test with the testing-magneto, or with the C machine should show continuity. Release the contact-arms and put in the safety-pin. A test should now show no continuity. After this test the safety-pin must not be removed until just before submerging the torpedo prior to firing. _It is absolutely necessary that the circuit-closer be closed water-tight._ =Priming the Contact Torpedo.=—Proceed as in priming the Service Torpedo. =Fuzing and Shipping the Contact Torpedo, and Shipping the Secondary Spar.=—Proceed as with the Service Torpedo, except that the contact spar leading-wires must be rove through the main spar, from aft forward, before fuzing the torpedo. The detonator must be spliced to the short legs of the leading-wires. =To Test the Circuit.=—The torpedo having been submerged, connect the inner ends of the leading-wires to the testing-magneto, or to the C machine. Close the safety-break and the hand-firing key and test. Under these circumstances continuity should be found. =To Fire at Will.=—Connect to the firing-battery, close the safety-break and, at the desired moment, close the hand-firing key. =To Fire on Contact.=—Connect to the firing-battery. Close the safety-break. When contact is made the contact-arms will be forced in, and the torpedo will explode. =_Note._=—The safety-break should be habitually left open, being closed only just before it is desired to put the circuit in condition to fire by closing either one of the two remaining breaks—that in the hand-firing key, when firing at will, or that in the circuit-closer, when firing on contact. IMPROVISED TORPEDOES.