116 THE UNIVERSE 



conductors reflected these waves, and the ocean's 

 surface sent them back when they impinged upon it. 



"Now, with upper air layers proven conductors, 

 the electric waves must be deflected from above as 

 well and bent downward to follow the earth's cur- 

 vature." 



And thus electric signals, silent but all pervading, 

 will before long circle our globe by their repeated 

 deflections through this great speaking tube around 

 the earth. The mysterious negative corpuscles, 

 more minute than our smallest atoms, thus are 

 themselves the very basis of the practicability of 

 wireless telegraphy, our latest invention. Nay, 

 more, may not these ions or corpuscles be atoms 

 of electricity, and, being a thousand times smaller 

 than atoms of matter, impregnate them with posi- 

 tive and negative force? 



Inventors have been endeavoring to send mes- 

 sages over long distances without wires ever since 

 the first tests were made in 1896. Only recently 

 Marconi has succeeded in sending them across the 

 Atlantic, two thousand miles through the air. 



The distance to which messages may be trans- 

 mitted and received depends on the amount of elec- 

 tric energy employed, the frequency of oscillation 

 in the radiating system, the length of the electric 

 waves emitted, the height of the perpendicular wires 

 from the ground, the medium through which the 

 waves are propagated, the sensitiveness of the 

 coherer or receiver, and the precision with which 

 the instruments are adjusted. 



Long electric waves are radiated to greater dis- 

 tances than shorter ones, and much depends on the 

 syntonic system, or tuning of the instrument, so as 



