FIRST APPARATUS 



133 



primary S goes to a sensitive telephone T. Two 

 horseshoe magnets are placed as shown in the 

 diagram, with similar poles together, and as the 

 wire string travels past them the magnetism induced 

 is retained by hysteresis, this being immediately 

 destroyed by the passing of the wireless oscilla- 

 tions through P, the magnetism shifting back 



FIG. 60. Arrangement first used by the Author for the 

 wireless transmission of pictures. 



again to the normal position. This change of the 

 induced magnetism with respect to the magnets 

 causes a sound in the telephone, which is suffi- 

 ciently sensitive to respond to currents of io~ 13 ampere 

 and less. 



The first wireless pictures transmitted with any 

 success and I am speaking of success from an 

 experimental point of view were obtained with the 



