48 PHOTO-TELEGRAPHY 



curve to the left of the first vertical line represents the 

 amount of light continually falling on the cell before 

 any additional illumination from the photographic 

 transparency falls upon it. Within the portion 



2\c* 

 selected -^- is almost constant, and on it will depend 



largely the shape of the triangular aperture in the 

 receiving diaphragm. 



The first photograph wired by Korn's new sele- 

 nium machines was received from Berlin at the 

 office of the French illustrated weekly paper, 

 L? Illustration, in October, 1907. It was a photo- 

 graph of President Fallieres, and came through 

 with considerable success. The first night of the 

 trials Berlin-Paris, Professor Korn and his wife, 

 his assistant Herr Will, and several post office 

 officials, and some of the leading newspaper men 

 of Paris, were present. As the telephone lines were 

 to be required for an hour or two, it was necessary 

 to make the experiments very late, and the line was 

 promised for midnight. After some minutes we 

 got the connection with Berlin, but there was an 

 annunciator bridged across it, and we could get 

 practically no current at Paris. Every effort was 

 made by the Director of Telephones, and we all 

 waited patiently until after two o'clock in the morn- 

 ing, with no result, and finally everyone was obliged 

 to leave, feeling both tired and disappointed. 



On the next occasion, however, the picture of 



