60 PHOTO-TELEGRAPHY 



instruments based on selenium for experiments 

 across the Atlantic. Herr Riihmer, whose work in 

 connection with wireless telephony is well known, 

 and who has contributed many valuable papers on 

 the physical properties of selenium,, claims now to 

 have completely overcome inertia in certain new 

 cells he has made. He is using selenium cells in 

 experimental trials to transmit by electricity a visual 

 image of an object or person, but as his work con- 

 cerns television and not the telegraphy of pictures, 

 it will not be discussed here. 



