The priming in the tube is sufficient to rupture the tubes and ignite the charge in the torpedo.
Fig. 2 shows a section of the circuit-closer, with the spiral spring slightly compressed, and the insulated bridge in contact with the insulated terminal, and the circuit closed. By dispensing with the electric fuze, and using in its place a piece of copper wire, any number of experiments may be made with an uncharged torpedo without adjustment or manipulation of any kind; it only being necessary to attach to the return wire near the battery a galvanometer or electric fuze to indicate the time of the impact.
The torpedoes here described are manufactured by J. Vavasseur and Co., at the London Ordnance Works; at which establishment the inventor has every facility in the supervision of the various details in the construction of the torpedoes, buoys, and brakes. Such supervision of the torpedoes and their equipments is highly essential to secure safety and efficiency.
TACTICS.
Torpedo vessels should, as a rule, attack under the cover of darkness. By the experience gained in blockade running in the late American conflict, we are assured that a vessel in rapid motion can, when it is dark, pass with impunity close under the fire of hostile vessels, armed with cannon.
In the more early stage of the torpedo, the tactics of vessels armed with torpedoes embraced modes of attack that are not now entertained. So general is becoming the use of torpedoes as a means both of defence and offence, that vessels, which may be at anchor or moored in a harbour or roadstead, would be protected by stationary torpedoes; the use of which admits also of vessels, when at anchor or moored, protecting themselves by placing a web of torpedoes in such manner as to render the attack of a hostile vessel or boats extremely hazardous, and therefore not likely to be attempted. But in the event of a vessel being at anchor in a harbour or roadstead unprotected, she could be attacked, as shown in the illustration of Tactics, under such conditions. As, however, vessels armed with torpedoes are intended to work the arm against vessels at sea or in motion, the management of the torpedo in so attacking vessels is the more important part of the code of Tactics.
It should be here remarked, that with a view to simplicity, the explanations will be confined to a single steamer, the attacking vessel adapted to the service of the arm in question, and confined also to a single vessel, the object of attack.