SCIENCE IN THE INDUSTRIAL WORLD 



so arranged that a short train of oscillations registers a 

 dot, while longer periods of oscillations register dashes. 

 If, then, the electric waves are made to fall upon the 

 coherer (or receiver, as it may be termed) in longer and 

 shorter intervals from the transmitting instrument, a 

 series of dots and dashes may be made at will in short, 

 the letters of the Morse code produced. 



Another great improvement in Marconi's wireless 

 system was the introduction of his vertical "air- wire" 

 or "aerial," which is a vertical wire carried to a great 

 height on poles or by means of a kite, such a wire act- 

 ing as an electric-wave absorber, collecting the waves 

 to act upon the little coherer. A great many of these 

 are sometimes used in combination, such "wave-gates" 

 being established at various Marconi stations for long- 

 distance messages. These aerials are also installed on 

 the masts of ships ; in such an arrangement one knob of 

 the exciter is attached to a heavy insulated wire which is 

 then led up the mast, terminating at the top in a cylinder 

 or sheet of zinc, or a piece of wire netting. 



METHODS AND RESULTS 



All these things sound very intricate and complicated 

 indeed, and it might be supposed that the actual send- 

 ing and receiving of wireless messages by this system is a 

 difficult matter. As a matter of fact the operating is 

 simplicity itself to the telegraphist. His actions are 

 practically the same as if he were sending an ordinary 

 land-telegraph message. When he works the key of 

 his sending instrument, his dots and dashes set up 



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