58 THOUGHTS ON NATURAL PHILOSOPHY. 



was the importance of the antenna, or aerial wire, 

 and of the earth connection. In its earliest form his 

 transmitting apparatus consisted of an induction 

 coil, one secondary terminal being connected to a 

 plate or cylinder of wire upheld by a pole. The 

 secondary terminals of the induction coil were also 

 connected to a spark ball discharger ; and in some 

 of his experiments he employed a kite or balloon to 

 uphold the elevated wire or plate, now called the 

 antenna. In the primary circuit of the induction 

 coil he inserted a key for breaking and making the 

 primary current in accordance with the signals of 

 the Morse alphabet. By pressing the key in the 

 primary circuit of the induction coil for a longer or 

 shorter time electric sparks of longer or shorter 

 duration were made to pass beween the spark balls 

 of the induction coil. Corresponding to these, trains 

 of electrical oscillations are set up in the insulated 

 wire or strip called the antenna ; and, corresponding 

 again to these groups of oscillations, trains of electric 

 waves, the duration of which corresponds with the 

 time during which the primary circuit of the in- 

 duction coil is closed, are sent out into space in all 

 directions. At the receiving station (many miles 

 away, and with the improved apparatus, thousands 

 of miles away) an antenna or insulated conductor is 

 erected similar to that at the transmitting station; 

 and by this means the waves are intercepted and 

 carried through the transmitter to the Morse printer, 

 by which the message is printed off. 



My point is that the action of matter on the ether 

 by contact, producing the waves which again act by 



