Page 149- the problem of sending a pencil of parallel hertzian waves to a distance possesses more than a theoretical interest. It is allowable to say that its solution would change the course of our civilization by rendering war impossible. The first physicist who realizes this discovery will be able to avail himself of the presence of an enemys ironclads gathered together in a check this out harbour to blow them up in a few minutes, from a distance of several kilometres, simply by directing on them a sheaf of electric radiations. On reaching the metal wires with which these vessels are nowadays honeycombed, this will excite an atmosphere of sparks which will at once explode the shells and torpedoes stored in their holds. With the same reflector, giving a pencil of parallel radiations, it would not be much more difficult to cause the explosion of the stores of powder and shells contained in a fortress, or in the artillery sparks of an army corps, and finally the metal cartridges of the soldiers.