NEW CONCEPTIONS IN SCIENCE 



and accepted Hertz's discovery as proof of the 

 identity of the two. Since then the Calcutta phys- 

 icist, Jagadis Chunder Bose, who was the first to 

 send a signal by wireless telegraphy, has succeeded 

 in producing electric-waves but two or three milli- 

 metres (about a tenth of an inch) long. The waves 

 sent out by these delicate little machines are much 

 nearer to the longest heat-rays than to the longest 

 electric-waves. The actual gap is only from three 

 millimetres to seventy micro -millimetres. Filling 

 this gap is really a mere mechanical detail. 



Thus is one great chapter in the physical account 

 of this world practically complete. 



Need it be added that as for the longer waves of 

 heat our senses grow dim and uncertain, for the 

 electric- waves we have no sense at all. They lie 

 outside our sensual world, and until science had de- 

 vised new senses, as it were, we had not so much as 

 a suspicion of their existence. Suppose that we 

 could be dowered with such an electric sense. The 

 spark-gap of the oscillator, or sender, answers to a 

 source of light, the receiver to a mechanical eye. If, 

 like this mechanical eye, our eyes were sensitive to 

 these electrical waves, then we might watch the prog- 

 ress of a play in Buenos Ayres or have witnessed 

 the struggles at Peking. Of what we might learn of 

 the unseen world about us only years of patient and 

 toilsome research will afford us so much as a hint. 



52 



