HERTZIAN WAVE WIRELESS TELEGRAPHY. 163 



sometimes described as being extravagant in power, but, as a matter 

 of fact, the most remarkable thing about it is the small amount of 

 power really involved in conducting it. On the other hand, Hertzian 

 wave manufacture is not altogether a matter of power. It is much more 

 dependent upon the manner in which the ether is struck. Just as half 

 an ounce of dynamite in exploding may make more noise than a ton 

 of gunpowder, because it hits the air more suddenly, so the formation 

 of an effective wave in the ether is better achieved by the right applica- 

 tion of a small energy than by the wrong mode of application of a much 

 larger amount. If we translate this fact into the language of electronic 

 theory, it amounts simply to this. It is the electron alone which has 

 a grip of the ether. To create an ether wave, we have to start or stop 

 crowds of electrons very suddenly. If in motion, their motion implies 

 energy, but it is not only their energy which is concerned in the wave- 

 making, but the acceleration, positive or negative, i. e., the quickness 

 with which they are started or stopped. It is possible we may discover 

 in time a way of manufacturing long ether waves without the use of 

 an electric spark, but at present we know only one way of doing this, 

 viz., by the discharge of a condenser, and in the discharge of large 

 condensers of very high potentials it is difficult to secure that extreme 

 suddenness of starting the discharge which we can do in the case of 

 smaller capacities and voltages. 



How strange it is that the discharge of a Leyden jar studied so 

 profoundly by Franklin, Henry, Faraday, Maxwell, Kelvin and Lodge 

 should have become an electrical engineering appliance of great im- 

 portance ! 



Whilst there are many matters connected with the commercial 

 aspect of Hertzian wave telegraphy with which we are not here con- 

 cerned, there is one on which a word may properly be said. The ability 

 to communicate over long distances by Hertzian waves is now demon- 

 strated beyond question, and even if all difficulties are not overcome at 

 once, it has a field of very practical utility, and may even become of 

 national importance. Under these circumstances, we may consider 

 whether it is absolutely necessary to place the signaling stations so 

 near the coast. The greater facility of transmission over sea has 

 already been discussed and explained, but in time of war, the masts 

 and towers which are essential at present in connection with trans- 

 mitting stations could be wrecked by shot or shell from an enemy's 

 battleship at a distance of five or six miles out at sea, and would cer- 

 tainly be done within territorial waters. Should .not this question 

 receive attention in choosing the location of important signaling sta- 

 tions? For if they can, without prejudice to their use, be placed 

 inland by a distance sufficient to conceal them from sight, their value 

 as a national asset in time of war might be greatly increased. 



