PHYSICS OF NINETEENTH CENT. ELECTRICITY. 587 



The great prize of 50,000 francs (,2,000), which was instituted by 

 the late Emperor of the French (Napoleon III.) in 1852, for the most 

 useful applications of the voltaic battery, to be awarded every five 

 years, was not awarded to any 

 person in 1857, or at all until 

 1864, when it was very deser- 

 vedly obtained by M. Ruhra- 

 korff for his induction coil. 



We have already given a 

 brief explanation of the two 

 greatest of Faraday's great 

 discoveries in electricity and 

 magnetism, viz., magneto-elec- 

 tricity and the induction of 

 currents by currents. The 

 applications, scientific and 

 industrial, of these principles 

 are innumerable, and in both 

 directions new applications 

 and exemplifications are con- 

 tinually produced. Within 

 the last few years, for example, 

 Graham Bell's Speaking Tele- 

 phone (page 546) has excited a 

 great deal of popular interest. 

 What, indeed, can appear more 

 wonderful than that a man 

 should be able to hear the very 

 words which are spoken 100 

 miles away, and should even 

 be able to recognize the voice 

 of the speaker ? The marvel 

 is greater when the extreme 

 simplicity of the telephone 

 apparatus is seen ; for of all 

 instruments for communicat- 

 ing intelligence at a distance, 

 the telephone, which repro- 

 duces the actual sounds of 

 spoken words, is the simplest FIG. 278. -THE STRATIFIED DISCHARGE. 

 in construction. Its action 



depends upon the principles which have been explained in the present 

 chapter, viz., magneto-electricity and electro-magnetism. 



An account of all Faraday's electrical and magnetic discoveries 

 would be equivalent to a treatise upon a great part of these sciences 

 themselves, and this it is not our aim to attempt. We must, however, 



