THE CENTURY'S PROGRESS IN PHYSICS 



But in the year 1819 there flashed before the philo- 

 sophic world, like lightning from a clear sky, the report 

 that Hans Christian Oersted, the Danish philosopher, 

 had discovered that the magnetic needle may be deflect- 

 ed by the passage near it of a current of electricity. 

 The experiment was repeated everywhere. Its validity 

 was beyond question, its importance beyond estimate. 

 Many men had vaguely dreamed that there might be 

 some connection between electricity and magnetism 

 chiefly because each shows phenomena of seeming at- 

 traction and repulsion but here was the first experi- 

 mental evidence that any such connection actually ex- 

 ists. The wandering eye of science was recalled to elec- 

 tricity as suddenly and as irresistibly as it had been in 

 1800 by the discovery of the voltaic pile. But now it 

 was the physical rather than the chemical side of the 

 subject that chiefly demanded attention. 



At once Andre Marie Ampere, whom the French love 

 to call the Newton of electricity, appreciated the far- 

 reaching importance of the newly disclosed relationship, 

 and, combining mathematical and experimental studies, 

 showed how close is the link between electricity and 

 magnetism, and suggested the possibility of signalling 

 at a distance by means of electric wires associated with 

 magnetic needles. Gauss, the great mathematician, and 

 Weber, the physicist, put this idea to a practical test by 

 communicating with one another at a distance of sev- 

 eral roods, in Gottingen, long before " practical " teleg- 

 raphy grew out of Oersted's discovery. 



A new impetus thus being given to the investigators, 

 an epoch of electrical discovery naturally followed. For 

 a time interest centred on the French investigators, in 

 particular upon the experiments of the ever-receptive 



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