CHAPTER XIV. 



WAY DUPLEX SYSTEM. 



A novel form of double transmission wag 

 invented by the writer soon after the com- 

 pletion of the harmonic system, and was an 

 outgrowth of it. It is still in use on some of 

 the railroad-lines. An ordinary railroad tele- 

 graph-line has an instrument in circuit in 

 every office along the road, chiefly for purposes 

 of train-dispatching. As we have heretofore 

 explained, whenever any one office is sending, 

 the dispatch is heard in all of the offices. The 

 "Way duplex" system permits of the use of 

 tho line for through business simultaneously 

 with the operation of the local offices. That is 

 to say, any station along the line may be tele- 

 graphing with any other station by the ordi- 

 nary Morse method, and at the same time mes- 

 sages may be passing back and forth between 

 the two end offices. 



This is accomplished by the following 

 method: At each end of the line there is a 

 tuned reed, such as we have described in our 

 last chapter, tli.it is kept constantly in vibra- 

 tion by a local battery during working hours. 

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