AUTOMATIC PRINTING EQUIPMENT 



407 



the multiplex code used on American land line multiplex circuits 

 would be the most suitable for high speed automatic submarine 

 cable transmission. Subsequent experience has indicated that the 

 original conclusion was amply justified and has shown that the Baudot 

 type of code, when used in connection with terminal apparatus of 

 suitable design, is probably faster than any of the other types of 

 codes which have been considered for high speed loaded cable operation. 



Outline of System 

 The multiplex system ^ used on land telegraph lines was in many 

 respects well suited to the requirements of loaded cable operation. 

 It was capable of operation at high transmission speeds, was more 

 economical of line time than other methods which were considered, 

 and provided for the division of trafific between a number of traffic 

 channels in a manner which afforded great flexibility in the handling 

 and routing of traffic and permitted the channel speeds to be fixed at 

 values which would allow the operating staff to work at maximum 

 efficiency. Its long continued use on land telegraph lines had resulted 

 in bringing the apparatus, operating methods and routines to a high 

 degree of perfection and the development of a thoroughly trained staff 

 skilled in the operation and maintenance of the equipment, all of 



SENDING I 



OCZDGZiGZlCZDDZlCZDIIZXZDCZIICIDCIIlCZI]! 



RECEIVING 



cot 



Fig. 3 



which was of inestimable importance in the successful application and 



operation of printing telegraph methods to submarine cables. 



The multiplex system provides for associating the line at the sending 



3 J. H. Bell, loc. cit. 

 27 



