312 PROCEEDINGS OF THE AMERICAN ACADEMY. 



The system can, of course, be readily used for wireless telegraphy 

 provided some method such as a chopper be used for making audible 

 the continuous transmission of power. One gap operating on from .0 to 

 .8 ampere will undoubtedly transmit up to 70 miles with some advan- 

 tages over the other systems. In addition to the advantages of high 

 efficiency, one wave length, etc., is the great gain in simplicity and 

 regularity, and the advantage of working directly on the commercial 

 voltages for hours with no attention. 



One of the most interesting applications of the aluminum-copper 

 gap is its successful use in wireless telephony. Professor G. W. Pierce 

 and the author have given the apparatus a thorough test in connection 

 with wireless telephony, and have carried on conversations for several 

 hours at a time between two distant stations with practically perfect 

 articulation. The remarkable constancy and regularity of the system 

 as a generator of continuous oscillations has been proved to be of great 

 value for the wireless transmission of articulate speech. This will 

 probably be the subject of a later communication. 



Jefferson Physical Laboratory, 

 Harvard University, 

 Cambridge, Mass. 



