THE FUTURE OF TRANSOCEANIC TELEPHONY 11 



number of requirements, perhaps none more important than the Atlantic 

 route, yet collectively of great consequence. Let us say that, in view of 

 all the other requirements, public service telephony across the Atlantic 

 deserves something like a tenth of the total facilities in tnis band. This 

 would mean an allotment of 400 kilocycles or 100 one-way telephone 

 channels, yielding 50 or more two-way circuits realizable under the natural 

 limitations of the medium and the other requirements placed upon it. 



Of course, the demand for such a number of transatlantic telephone 

 circuits will depend in large measure upon the economy with which they 

 can be realized, but the estimate serves at least the purpose of pointing 

 out that short waves can provide physical facilities for a volume of tele- 

 phone communication far beyond that now obtaining. Surely we can 

 anticipate with confidence a great growth of transatlantic telephone traffic, 

 but in proportion as the demands for service grow and we come closer to 

 the realization of the ultimate physical possibilities, the more serious 

 becomes the threat of interruption to this service by magnetic storms. 



These conclusions lead us to reconsideration of the transatlantic tele- 

 phone cable as an auxiliary to short-wave systems. It is readily apparent 

 now, however, that a single-channel cable such as we projected in 1929 

 would be of little value in supplementing a radio telephone service of so 

 many channels as there may be in the future. To be of any real value in 

 this situation, the cable also must be capable of carrying a considerable 

 group of telephone channels. It was toward such a possibility that we 

 turned when the project of a single-channel cable was suspended. We have 

 made considerable progress in that direction, and I would like to tell you 

 about it, if you wiU excuse my presenting a proposal which has still many 

 elements of speculation in it. 



It was obvious at the start that a multi-channel telephone cable to cross 

 the ocean would have to be provided with intermediate repeaters since 

 even a single-channel cable without repeaters required going to practical 

 extremes in structural design. Consideration of mechanical difficulties 

 ruled out locating the repeaters elsewhere than on the ocean bottom. 

 Problems of laying and lifting made it obvious that the repeater housing 

 should, if possible, be incorporated within the cable structure and treated 

 as a part of the cable rather than as an appendage to it. Hence we were 

 led to develop a small-diameter cylindrical housing to be incorporated as a 

 part of the cable underneath its armor. The whole structure had to be 

 flexible so that it could be bent around a cable drum and passed over the 

 bow or stern sheave of a cable ship. 



The structure of the repeater housing which was devised comprises first 

 a succession of pressure-resisting steel rings each having a diameter of about 

 1^ inches and a width of | inch. Over these is slid a succession of thinner 



