132 GEORGE HERBERT STOCKBRIDGE 



minutest detail and every broadest combination; and it in- 

 volved also the expenditure of over $2,000,000 in money. 



Especially exceptional are Edison's powers of observation, 

 quick conception, and selection. Being always by nature 

 and by his responsibilities in the creative state of mind, his 

 observing powers are kept in constant play, while his exhaust- 

 less knowledge of the needs of his art and of the aptitudes of 

 contributory arts enables him to gauge with marvellous 

 quickness the possibilities of a new discovery and to choose 

 just the elements and combinations which will enable him 

 to embody his conception. And once started on the track 

 of a new idea of this sort, he pursues it with unresting energy 

 until he has demonstrated its practicability. It was in this 

 way that he applied the telephonic diaphragm to the creation 

 of the phonograph. In this way, too, he employed Hughes' 

 discoveries regarding certain qualities of carbon to the pro- 

 duction of the Edison telephonic transmitter. Dr. Otto A. 

 Moses, himself an inventor of note, gave to the New York 

 Electrical society not long ago, an account of Edison's in- 

 vention of the so-called '' Motographic relay." This invention, 

 of striking originality, was, according to Dr. Moses, the sequel 

 of Edison's having observed, while moving a spoon over a 

 sheet of paper which was resting on a brass plate joined to a 

 battery, that the sheet seemed to slide more freely while a 

 current was passing. The completed relay was ready in a few 

 days. Some time after this, being challenged to show that 

 he could produce a new order of telephonic receiver as he had 

 in the case of the transmitter, he converted the motographic 

 relay into a sound receiver of marvellous sensitiveness and 

 efficiency. These anecdotes reveal the true characteristics 

 of Edison's genius, — the quahties already noted, and his 

 alertness of mind, his pride in his work, his readiness to accept 

 a challenge, his chess player's delight in the solution of new 

 problems. 



It could hardly be avoided that some great inventions 

 should be popularly assigned to Edison exclusively, the credit 

 for which is partly due to others. Thus, the origination of 

 the duplex telegraph, for which Dr. Joseph N. Stearns of 

 Boston prepared the way, is generally ascribed to Edison 



