508 BELL SYSTEM TECHNICAL JOURNAL 



expected to be followed by the development of small circuit groups 

 between the more important continental telephone networks, each 

 group being operated as a unit between fixed terminal points. The 

 advantages, while circuit groups are small, of concentrating inter- 

 continental traffic as far as possible between the same terminals 

 rather than diverting it to individual circuits between different 

 terminal points, are great. As an illustration, betw^een the United 

 States and Europe where the volume of traffic has already led to the 

 development of a circuit group, the operation of the six circuits now 

 contemplated as a unit is estimated to give for the same grade of 

 service a capacity one third greater than would be afforded by six 

 separate circuits of the same character between different terminal 

 points. The inclusion in one group of circuits of three different types, 

 short-wave radio, long-wave radio and cable, will afford a continuity 

 of service and an insurance against interruption far beyond what 

 could be achieved with single circuits. A single circuit group between 

 the two continental networks is also advantageous from a service 

 standpoint because of the simpler operating arrangements. 



While the first stage in the development of intercontinental business 

 appears to indicate the concentration of intercontinental traffic in so 

 far as the extent of continental networks makes this practicable, a 

 second stage in the development will naturally be the establishment 

 of additional circuit groups between other points of the networks. 

 This becomes economical and desirable from a service standpoint 

 when the original circuit group becomes large enough to permit of 

 subdivision without great loss in efficiency and when the amount of 

 traffic which can be conveniently handled through additional points 

 in the continental wdre networks is sufficient to fill the time of a group 

 of several circuits. Hence, it is to be expected that the ultimate 

 switching plan for w^orld-wide telephony will include between large 

 continental networks, such for example as exist in Europe and in the 

 United States, a number of groups of overseas circuits between 

 different terminal points selected so as to handle the traffic most 

 conveniently and economically. Such a plan would also necessarily 

 provide arrangements for the use of alternate routes. In any case 

 the ultimate best pian from the standpoint of service and economy 

 will depend upon the \olume of traffic. 



The technical achievements which have made possible the linking 

 together of the continents of the earth with telephone circuits are in 

 a high degree romantic. What may be accomplished for the benefit 

 of mankind by the continued development of this world-wide telephone 

 network depends upon what is said over the telephone circuits. It is 



