32 Inatigural Address by the President. 



mental data of Faraday and others, and throwing on them the 

 clear decisive light of mathematical deduction, concluded not 

 only that there was a connection between light and electricity, 

 but that light itself was really an electromagnetic phenomenon. 

 He showed also that disturbances in the aether were produced 

 by electric discharges, and that if such discharges were repeated 

 with sufficient rapidity they would become the source of aether 

 waves similar to light waves, but much longer, and having 

 many surprising peculiarities. To such waves, for instance, 

 certain opaque non-conducting substances such as pitch vulcanite 

 and so forth would be found transparent. To these they would 

 offer no more opaqueness than glass does to light. Metals 

 would be opaque, but would have electric disturbance produced 

 in them by the impact of these electromagnetic aether vibrations. 



The experimental confirmation of these deductions was, 

 however, still to be made. In 1883 Prof. George F. FitzGerald 

 drew my attention to this, and pointed out that if we could 

 produce electric discharges at the rate of 50 or 100 million per 

 second we could verify Maxwell's prophesy. I could think of 

 no current breaker which could work at such a rate. I 

 mention this to show how narrowly one sometimes misses 

 becoming famous. If we had only thought of the oscillatory 

 discharge of an ordinary induction coil or leyden jar it would 

 not have been left to Herz five years later to show that the 

 oscillations of such discharges have the required frequency for 

 radiating Maxwell's waves and to invent also means for detect- 

 ing the radiations at a distance from their source. 



In the working of such an induction coil as this now before 

 you, at each spark there is an inconceivably rapid surging 

 backwards and forwards of the current forming the spark, so 

 that what looks like one spark is really a discharge oscillating 

 in opposite directions between the brass knobs with extreme 

 rapidity. By means of a suitable receiving instrument, telegraphy 

 can be carried on by the usual code of short and long flashes. 

 Such elementary apparatus as I can show you here works very 

 well across the lecture room as you see. Marconi has been able 

 by more perfect arrangements to send messages over 40 miles. 



