CHAPTER Xltl. 



MULTIPLE TRANSMISSION. 



Although the printing and automatic sys- 

 tems of telegraphing are used in America to 

 some extent, the larger part is done by the 

 Morse system of sound-reading and copying 

 from it, either by pen or the typewriter. In 

 the early days only one message could be sent 

 over one wire at the same time, but now from 

 four to six or even more messages may be sent 

 over the same wire simultaneously without 

 one message interfering with the other. Like 

 most other inventions, many inventors have 

 contributed to the development of multiple 

 transmission, till finally some one did the last 

 thing needed to make it a success. The first 

 attempts were in the line of double transmis- 

 sion, and many inventors abroad have worked 

 on this problem. 



Moses G. Farmer of Salem, Mass., proposed 

 it as early as 1852, and patented it in 1858. 

 Gintl, Preece, Siemens and Halske and others 

 abroad had from time to time proposed dif- 

 ferent methods of double transmission, but no 

 one of them was a perfect success. When the 

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