Popular Science Monthly 



375 



translate the Morse code and write out 

 the messages for delivery. The system 

 is entirely practical, and is used in con- 

 nection with the ocean cables. In the 

 United States it is not favored for inter- 

 city telegraphing because of the loss of 



and expense in message handling are 

 saved, and the good features of present- 

 day rapid wire line service are largely 

 due to these installations. 



The newest and most perfect page- 

 printing telegraph is that which the 

 \\'estern Electric engineers have recently 

 completed. In this system a single 

 wire is used not only to carry eight 

 messages simultaneously, four in each 

 direction, but to print them on blanks 

 at the receivers, ready for 

 delivery. Thus the speed of 

 direct printing operation 

 (fifty words per minute) is 

 combined with a distribution 



The receiving instru- 

 ment. A telegraph blank 

 is inserted in the instru- 

 ment, and as the perfo- 

 rated tape passes through 

 after receiving its im- 

 pulses over the wire, the 

 message appears in type- 

 written form, ready to be 

 delivered 



time which results from the se- 

 ries of processes through which 

 messages must pass. 



Automatic telegraphy suggest- A sending operator at the keyboard perforator. This 

 ed l^rinting telegraphy, in which instrument is much Uke a typewriter, but instead ot 

 the mess'i^e received annc'irs in P""ting the letters a group of punches are controlled by 

 tnc message leceuea appears ni ^^^ ^^^^ ^^^ p^^^^j^ ^ ^^p^ ^-^^^ various combmationa 



of holes 



typewritten form. The first of 

 these instruments, like the stock- 

 ticker, printed their messages on paper 

 tapes. Soon it became possible to op- 

 erate page-printers over considerable 

 distances by wire. In these a typewriter 

 keyboard transmitter, either directly or 

 through a punched tape, operates over 

 the line a typewriter receiver. The mes- 

 sage is thus printed ready for delivery 

 almost as soon as the transmitting op- 

 erator punches it out on the sounding 

 keyboard. Such printing systems usual- 

 ly o])erate up to fair typewriting speeds 

 of fifty words per minute or so, and can 

 be duplexed. By their use much time 



of one telegraph line among eight pairs 

 of sending and receiving operators. The 

 increases of speed and economy pro- 

 duced by such an arrangement are al- 

 most self-evident. 



The apparatus used in this new quad- 

 ruple-duplex system is built up in a group 

 of transmitting, receiving and accessory 

 units. (Ine of the illustrations shows a 

 sending operator at the keyboard per- 

 forator. This instrument is much like a 

 typewriter, but instead of printing the 

 letters a group of punches are controlled 

 by the keys and perforated on a paper 



