Many inventors have lately been devoting their attention to the steering of torpedoes without the need of connecting wires, and some consider that wireless torpedoes would be an efficient antidote to submarine boats. That such weapons can be produced there is little doubt, but that they will be sufficient to drive submarines from the seas, appears extremely doubtful—at any rate just at present. The possibility of a battleship or a cruiser being able to inform herself of the advance of a submarine vessel must be considered. Water is an excellent conductor of sound, and a microphone or some similar apparatus could be arranged to give notice of the approach of an invisible ship, even when it was some way away. The ironclad could then surround herself with her torpedo nets, or steam away leaving the submarine powerless to overtake her. The French are very naturally watching with intense interest the attitude of the British navy towards submarine boats, and the experiments that have lately been carried out by the officers of H. M. S. _Vernon_ with a view to discovering the most effective method of destroying under-water craft, have been carefully followed by our neighbours over the channel. According to a recent article in _Le Yacht_ we are endeavouring to get submarines prohibited as unfair weapons, but being doubtful of such a “happy result,” have devised a torpedo that is fired the instant one is sighted. We have also perfected a “Röntgen ray device” whereby the British sailor will be enabled to scan the ocean depths and sight the submarine even if it lurk at a depth of 20 feet below the surface. _Le Yacht_, however, thinks this device would cut both ways, and would enable the submarine to find its prey without coming to the surface at all. No official information regarding the Röntgen ray device has up till now been vouchsafed, and it may after all exist nowhere else than in the heated imagination of French writers who hate perfidious Albion more than ever since she has considered the question of accomplishing the destruction of France’s submarine flotilla. M. Lockroy, in a recent article in the _Matin_, suggested that it would only be possible to fight against submarines when the steering of balloons had been discovered, the black form of the vessel being very easily distinguished in the water from a certain height. PART II CHAPTER IX THE EARLY HISTORY OF SUBMARINE WARFARE Although no mention of a submarine vessel having been actually constructed can be found earlier than the seventeenth century, and although the torpedo and the mine were not invented till still later, the art of submarine warfare and subaqueous exploration dates back to a very much earlier period.