824 The Outline of Science 



day-bound people weather prospects." The broadcasting of 

 news has reached such great dimensions that restrictions of 

 some kind are likely to be imposed. In present conditions some 

 limit is necessary for the use of the radio-telephone communica- 

 tion between single individuals. Wireless telephony is used pri- 

 marily for broadcasting news, conveying commercial information, 

 and for providing general entertainment. At present the Mar- 

 coni Company broadcast a concert once a week. The wireless 

 amateurs receiving messages in Great Britain number something 

 like 8,000. In their homes they can enjoy the music broadcasted 

 from distant concert-rooms, or amuse themselves by communicat- 

 ing with friends who may have transmitting sets, or by tapping 

 wireless messages from unknown sources. To-day any one, by 

 making a request at any postal telegraph office in Great Britain, 

 may have a message transmitted by wireless to a passenger on 

 board an ocean liner in mid-ocean. 



It may be that one day every passenger train will be 

 equipped with wireless apparatus. Such an experiment has been 

 already made by the American Marconi Company and communi- 

 cation maintained with the train over the whole course of its 

 journey, and it was travelling at times at the rate of sixty miles 

 an hour. Sixty miles an hour is very slow compared with an 

 aeroplane flying at 200 miles an hour and picking up wireless 

 messages, but how inconceivably slow are both compared with 

 the speed of electromagnetic waves propagating wireless messages 

 at the speed of 186,000 miles a second. This is the speed of 

 light; it is also the speed of electromagnetic waves, a fact which 

 gives rise to interesting speculations. 



Wireless has made travel by sea safer than it ever was. It 

 would probably be well within the mark, it is estimated, to say 

 that at least 5,000 persons owed their rescue from death by 

 drowning to wireless even before the Great War in 1914. How 

 many more were saved during the enemy's submarine attacks on 

 merchant vessels it is impossible to say. In innumerable ways 



