188 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1908. 



may be heard if persons are walking across the room, etc. This 

 makes listening less of a strain than when talking over wire line. 

 Even during severe atmospheric disturbances the talking is not inter- 

 fered with to any noticeable extent, provided, of course, that an inter- 

 ference preventer is used. 



A comparative test was made with talking between Brant Eock 

 and Brooklyn by wireless and by wire telephony. The talking over 

 the wire line was done from a long-distance station in Brooklyn. 

 The wireless transmission was considerably the better. The fact that 

 the wire line included in its circuits a cable from New York to Brook- 

 lyn was of course a disadvantage, but even allowing for this, prac- 

 tice and theory appear to be in agreement to the effect that transmis- 

 sion by wireless telephony over long distances is better than by wire 

 line. 



This method should be of especial value to independent telephone 

 companies, which have their local exchanges, but no long-distance 

 lines, especially since no franchises or rights of way are necessary. 



POSSIBILITIES. 



Local Exchanges. 



There is no immediate prospect that wireless telephony will take 

 the place of local exchanges. The difficulty in regard to the number 

 of tunes can be overcome, but the fact remains that high frequency 

 oscillations can not be transmitted over wire, and hence each sub- 

 scriber must have his ow^n generating station. At the present time 

 no method is known which would be practical if placed in the hands 

 of a subscriber. If such means should be found it would be very con- 

 venient to call up directly instead of through an exchange, but as I 

 see it there are no immediate prospects of this. 



Long-distance Lines. 



I believe, however, that there is a field for wireless telephony for 

 long-distance lines. The present long-distance lines are very expen- 

 sive to construct and maintain, and a storm extending over any 

 considerable section of country inflicts considerable loss on the tele- 

 phone companies. Moreover, the distance of transmission is limited 

 by the electrostatic capacity of the line, as I understand it. Wire- 

 less telephony would have the following advantages : 



1. The initial cost would be very much less than that of wire lines. 



2. The maintenance would be practically negligible in comparison. 



3. In case of any breakdown it would be right in the station and 

 not at some unknown point outside on the line. 



4. The depreciation would be comparatively small. 



5. The number of employees required would be smaller. 



