There is this immense fundamental difference between the automobile torpedo and the gun--the torpedo has no trajectory: it travels horizontally and hits below water, so all its hits are vital hits; but not so the gun--only in a few places are gun hits vital, and those places are armoured. It is not feasible to armour the bottoms of ships even if it were effectual--which it is not. But the pith and marrow of the whole matter lies in the fact that the Submarine Boat which carries this automobile torpedo is up to the present date absolutely unattackable. When you see Battleships or Cruisers, or Destroyers, or Torpedo Boats on the horizon, you can send others after them to attack them or drive them away! You see them--you can fire at them--you can avoid them--you can chase them--but with the Submarine Boat you can do nothing! You can’t fight them with other Submarine Boats--they can’t see each other! Now for the practical bearing of all this, and the special manner it affects the Submarine Boat and the Army and the Navy--for they are all inextricably mixed up together in this matter:-- As regards the Navy, it must revolutionise Naval Tactics for this simple reason--that the present battle formation of ships in a single line presents a target of such a length that the chances are altogether in favour of the Whitehead torpedo hitting some ship in the line even when projected from a distance of several miles. This applies specially to its use by the Submarine Boat; but in addition, these boats can, in operating defensively, come with absolute invisibility within a few hundred yards to discharge the projectile, not at random amongst the crowd of vessels but with certainty at the Admiral’s ship for instance, or at any other specific vessel desired to be sent to the bottom. It affects the Army, because, imagine even one Submarine Boat with a flock of transports in sight loaded each with some two or three thousand troops! Imagine the effect of one such transport going to the bottom in a few seconds with its living freight! Even the bare thought makes invasion impossible! Fancy 100,000 helpless, huddled up troops afloat in frightened transports with these invisible demons known to be near. Death near--momentarily--sudden--awful--invisible--unavoidable! Nothing conceivable more demoralising!