APPLIED SCIENCE 



II. WIRELESS TELEGRAPHY AND TELEPHONY 



REMARKABLE progress has been made in recent years 

 in wireless telegraphy and wireless telephony a new 

 department of applied science, which has already pro- 

 duced astonishing results. Wireless messages are flashed over 

 great distances with the speed of light, across land and sea, from 

 continent to continent; as one writer has picturesquely put it, 

 "the whole of our planet is now converted into one vast audi- 

 torium through which human speech can be transmitted by wire- 

 less telephony." Articulate speech can be transmitted across 

 the Atlantic ; the traveller on a great liner, far out on the ocean, 

 can listen in a comfortable easy chair to a concert going on in 

 far-off Paris, London, or New York. The aviator, thousands 

 of feet high in the air, lost in the clouds or in a thick fog it may 

 be, can receive help and direction by wireless messages, for it is 

 quite possible to carry on conversation between the pilot of an 

 aeroplane in the clouds and a wireless operator at a land station. 

 Wireless direction-finding is destined to be of great service in 

 guiding aviators safely to their destination. 



There are, it is said, one million private people receiving 

 wireless messages in America. This number had grown from 

 600,000 in the course of one year. "There is transmitting at all 

 hours of the day," we read ; "news of topical interest is flashing 

 all the time. City men get their stock exchange quotations, 

 women the current prices from various shops, sporting and holi- 



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