112 Improvements in Long-distance Telephony [March 27, 



it is thus possible to modulate power to the extent of 10(.) or 150 

 kilowatts. 



A very promising method of varying the amplitude of the emitted 

 waves appears to be by the insertion of a speaking microphone in the 

 exciting circuit of a high frequency alternator, such as that of Gold- 

 schmidt. It will be thus possible to modulate in accordance with 

 the wave form of articulate speech a large antenna current without 

 actually passing that current through any form of microphone. The 

 modulated current is then merely a small current of a few amperes. 



Summing up the position, we can say that lineless telephony up 

 to 500 or 600 miles is now possible, and there appears to be no 

 insuperal)le obstacle to prevent it from being conducted across the 

 Atlantic ocean. If this were ever done, and the New York to San 

 Francisco line telephony accompUshed, it might be possible, with one 

 repetition of a message, to speak articulately from London to places 

 in California. Long before this, however, is achieved, wireless 

 telephony will doubtless have come into use for moderate distances 

 between ships and ship and shore. Mr. Marconi has recently directed 

 much attention to this sulgect with the object of improving the 

 speech transmission and simplifying the apparatus. He has invented 

 for this purpose new and effective transmitters and receivers, and 

 has conducted demonstrations between ships of the Italian Xavy. 



It would be an advantage to possess a simple and easily worked 

 form of wireless telephone apparatus that could be installed on ships 

 for intercommunication, so that ships' oflBcere and others who have 

 not had the special training necessary to read Morse signals by ear 

 could on necessity communicate with distant vessels by actual speech, 

 and call for help in the hour of need. 



From this brief statement on a small portion of this suljject it 

 will be seen that we have by no means come to the end of invention 

 in connection with telephony. 



Achievement has been great since Alexander Graham Bell gave 

 us 38 years ago the exquisitely simple receiver which bears his name, 

 and at once made possible commercial telephony, when coupled with 

 the invention of the microphone and carbon transmitter made by 

 Hughes and Edison and other great pioneers. 



Let no one, however, think that the field is exhausted. The 

 chief prol)lems have been solved, but those who come to the task 

 with adequate powers of scientific investigation or original invention, 

 still find in the various departments of practical telephony an 

 abundant opportunity to enlarge our knowledge or improve a means 

 of coihmunication, which, even if it contributes at tinaes to test our 

 patience, has yet become so essential to our modern life. 



[J. A. F.] 



