Telephone transmission over long distances

In this paper are pointed out some of the similarities and contrasts of power transmission and telephone transmission over long distances. The problems of telephone transmission on open-wire lines are illustrated by a discussion of the methods by which the over-all efficiency of the transcontinental telephone circuit has been greatly improved. A brief discussion is given of recent important developments in telephone transmission through cables over long distances. An outline is given of the results obtained in the commercial, application of carrier telephone and telegraph systems. Finally, a demonstration talk between Havana, Cuba, and Avalon on Catalina Island off the Pacific coast, is described as an illustration of what can be done with the commercial telephone system in its present stage of development.