1908.] 0)1 Transatlantic Wireless Telegraphy. 127 



from daylight to darkness would occur almost simultaneously in the 

 whole of the medium between the two points. 



In the same manner a storm area in the path of the signals often 

 brings about a considerable weakening of the received waves, whilst 

 if stormy conditions prevail all the way across the Atlantic no inter- 

 ference is noticeable. Electric wave shadows, like sound shadows, 

 may be formed by the interference of reflected waves with the direct 

 waves, whereby signals may be much less effective or imperceptible 

 in the area of such electric wave shadow. 



In the same manner as there exist periods when signals across the 

 Atlantic are unusually weak, there exist other conditions, especially 

 at night, which make the signals abnormally strong. Thus on many 

 occasions ships, and stations equipped with apparatus of a normal 

 range of 200 miles, have been able to communicate over distances of 

 over 1000 miles. This occurred recently when a ship in the English 

 Channel was able to correspond with another in the Mediterranean. 

 But the important factor about wireless telegraphy is that a service 

 established for a certain distance shall be able to maintain reliable 

 communication over that distance. 



The erection of long-distance stations for the purpose of tele- 

 graphing across the Atlantic met at the outset with the severe 

 criticism of a certain important section of the English technical press, 

 which, altliough one would imagine it existed for the purpose of en- 

 couraging and promoting the progress of electrical science and industry, 

 always seemed more inclined to champion the particular interests of 

 the cable companies. 



Without wishing to enter into any controversy on this point, 

 I venture to predict that some of the statements published with 

 reference to long-distance wireless telegraphy will make very amusing 

 reading in a few years to come. 



I am here reminded of an anecdote related to me about Michael 

 Faraday. He had been displaying what appeared to be clumsily 

 made rings or coils which, as we all now know, were the forerunners 

 of the present-day dynamo. It appears that someone, pointing to 

 the coils, asked whatever could be the use of such apparently useless 

 articles. Faraday's answer was in the form of a question : " What 

 is the use of a baby ? " he said. 



The analogy is, of course, not quite applicable to wireless tele- 

 graphy at the present day. This new method of communication is 

 no longer an infant, but has now reached the stage of vigorous youth, 

 and is fast approaching manhood. 



Long-distance stations are now in course of erection in many 

 parts of the world, the most powerful of all being that of the Italian 

 Government at Coltano, and I have not the slightest doubt but that 

 telegraphy through space wiU soon be in a position of affording com- 

 munication between distant countries at cheaper rates than can be 

 obtained by any other means. 



