MULTIPLEX TELEPHONY AND TELEGRAPHY SQUTER. 153 



pect for the future. It is rather considered that the whole system of 

 intercommunication, including both wire methods and wireless 

 methods, will grow apace, and as each advance is made in either of 

 these it will create new demands and standards for still further 

 development. We need more wireless telegraphy everywhere, and 

 not less do we need more wire telegraphy and telephony everywhere 

 and, again, more submarine cables. The number of submarine 

 cables connecting Europe with America could be increased many 

 times and all of them kept fully occupied, provided the traffic were 

 properly classified to enable some of the enormous business which 

 is now carried on by mail to be transferred to the quicker and more 

 efficient cablegram letter. That time will surely come when the 

 methods of electrical intercommunication will have been so developed 

 and multiplied that the people of the different countries of the world 

 may become real neighbors. 



Accustomed to the methods of transmitting energy for power pur- 

 poses by means of wire, it is a matter of wonder that enough energy 

 can be delivered at a receiving antenna from a transmitting point 

 thousands of miles distant to operate successfully receiving devices. 

 The value of a metallic wire guide for the energy of the electric waves 

 is strikingly shown in the above experiments, and it furnishes an 

 efficient directive wireless system which confines the ether dis- 

 turbances to closely bounded regions and thus offers a ready solution 

 to the serious problems of interferences between messages which of 

 necessity have to be met in wireless operations through space. 



The distortion of speech, which is an inherent feature of tele- 

 phony over wires, should be much less, if not practically absent, 

 when we more and more withdraw the phenomena from the metal 

 of the wire and confine them to a longitudinal strip of the ether which 

 forms the region between the two wires of a metallic circuit. 



The ohmic resistance of the wire as shown can be made to play a 

 comparatively unimportant part in the transmission of speech, and 

 the more the phenomena are of the ether, instead of metallic con- 

 duction, the more perfectly will the modified electric waves, which 

 are the vehicle for transmitting the speech, be delivered at the receiv- 

 ing point without distortion. 



It has been shown that the phenomena of resonance, which are 

 met with in so many different branches of ]:>hysics ? exhibit very 

 striking and orderly results when applied to electric waves propagated 

 by means of wires. By utilizing this principle it has been shown 

 that the receiving current at the end of the line may be built up and 

 amplified many times over what it would be with untuned circuits. 



The tuned electrical circuit at the receiving end readily admits 

 electromagnetic waves of a certain definite frequency, and bars 

 from entrance electromagnetic waves of other frequencies. This 

 permits the possibility of utilizing a single circuit for multiplex 

 telephony and telegraphy. 



