146 LEADING AMERICAN MEN OF SCIENCE 



sounds were being emitted. He then turned toward the man with 

 the utmost firmness and said, "I do not know how you make the 

 sounds, but this I perceive very clearly: they do not come from 

 the room but from your person." It was in vain that the operator 

 protested they did not, and that he had no knowledge how they 

 were produced. The keen ear of his examiner could not be 

 deceived. 



Some time afterward Henry was traveling in the east, and took 

 a seat in a railway car beside a young man, who finding who his 

 companion was, entered into conversation with him, and informed 

 him that he was a maker of telegraph instruments. His advances 

 were received in so friendly a manner that he went further yet, 

 and confided to the Professor that his ingenuity had been called 

 into requisition by spiritual mediums, to whom he furnished the 

 apparatus necessary for the manifestations. Henry asked him 

 by what mediums he had been thus engaged, and was interested 

 to find that among them was the very man he had met at the 

 Smithsonian Institution. The sounds which the medium had 

 emitted were then described to the young man, who in reply stated 

 that the apparatus had been constructed by himself, and ex- 

 plained its structure and working. It was fastened around the 

 muscular part of the upper arm, and so devised that the sounds 

 would be produced by a simple action of the muscle, unaccom- 

 panied by any motion of the joints of the arm, and therefore en- 

 tirely invisible to a bystander. 



On the whole we must class Joseph Henry among those men 

 whose lives afford the most interesting examples- for the guidance 

 of youth. He who, at the present day, has to do with public life 

 may well be discouraged by the selfishness of its spirit and the 

 extent to which routine takes the place of reason in all its opera- 

 tions. Under these circumstances the spectacle of a man ani- 

 mated by the most exalted impulses, .devoting his energies to the 

 promotion of good works on the fy'ffhfst pj'ane. and leaving after 

 "Him none but fragrant memories, ought to be a source of encour- 

 agement and inspiration to every young man who is able to follow 

 in his footsteps. 



