APPLICATION OF PRINTING TELEGRAPH 



607 



graph system and sufficient equipment for adding another by providing 

 suitable filters and a small amount of additional apparatus. 



The connection of the printers to the telephone circuit is shown 

 schematically in Fig. 4. The transmitting telegraph circuits are not 



Fig. 3— Equipment for use in applying printing telegraph signals to the trans- 

 atlantic radio telephone circuit at the technical operator's position. 



connected permanently to the radio channel. When it is desired to es- 

 tablish the telegraph circuit, the connection is made through the opera- 

 tor's cord circuits into the transatlantic two-wire telephone circuit in a 

 manner similar to that used to connect telephone subscribers. Audible 



