274 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 5 



SOME HISTORY 



A transatlantic cable was envisioned not many years after the electric 

 telegraph had been born. As early as 1840, telegraphy was being 

 applied over land circuits, both underground and overhead. 



The first transatlantic telegraph cable, laid in 1858, failed a few 

 weeks after it had been put in service. It was 1866 before more scien- 

 tific studies, chiefly under the direction of Sir William Thompson 

 (later Lord Kelvin), inspired renewed faith in the project so that a 

 new cable could be laid which continued to operate satisfactorily. The 

 foresight, courage, and determination of Cyrus W. Field, an Ameri- 

 can, were also powerful factors in the ultimate success of the under- 

 taking. 



Decades after the first transatlantic telegraph cable there came radio 

 telegraphy, then radio telephony. Transatlantic radio telegraphy 

 started with the Marconi experiments in 1901. In 1927 commercial 

 transatlantic radio telephony was inaugurated. This has grown over 

 the years until now there are some 15 radio-telephone circuits in 

 operation between the two continents. 



Radio has the advantage of being comparatively inexpensive as 

 compared with transatlantic cables, but radio, either telegraph or 

 telephone, for the distances involved, has proved to have serious 

 weaknesses. The wavelengths that are available and useful for the 

 single-span operation across the Atlantic are greatly dependent on 

 Nature's vagaries. Transmission is frequently interrupted for hours 

 at a time, particularly in periods of unusual sunspot activity. 



It was not until about 1928 that advances in the technique of con- 

 structing submarine cables, together with the science of electronics, 

 had reached the point where serious consideration could be given to the 

 design and laying of a transatlantic telephone cable. The American 

 Telephone and Telegraph Co. made a good start on tliis project, but 

 this was interrupted by economic considerations resulting from the 

 depression of the thirties. Had it not been so interrupted, it is likely 

 that such a cable would have been installed. It would have provided 

 a single reliable talking path across the Atlantic. Its cost, however, 

 would have been many times that of a single radio-telephone link. 



As a technical achievement, it would have had something like 1,000 

 times the message-carrying capacity of the original transatlantic tele- 

 graph cable. In addition to taking advantage of improved materials 

 and cable construction, it would have incorporated at the terminals 

 vacuum-tube amplifiers capable of boosting the feeble voice power of 

 a telephone transmitter manyfold to enable it to override the liigh at- 

 tenuation of the cable for the voice currents. 



The history of transatlantic communication is fascinating and has 

 been well documented. In the Kelvin lecture before the Institution 



