Abstract :
The speed of the cable telegraphy is not satisfactory; the slow work makes the cabling very expensive. The direct-current impulses are lengthened on a long cable, because the long cable vibrates with its own natural frequency, which is very low. The impulses of the direct current overlap, over a certain limit. Alternating currents do not suffer such overlapping. The oldest form of the alternating-current application is the inverse current. Especially Picard and Gott attained good results with their inverse current systems. Another direction for increasing the speed of the cabling is worked out by the various cable-relays; Gulstad´s, Muirhead´s, Heurtley´s and S. G. Brown´s relays are discussed. The speed is not yet doubled by the aforementioned relays. The attempts with the high-frequency system on ordinary cables are discussed. The theory of the resistance of the cable is given, and different cables are taken into the computation. The cable rapid telegraphy is solved by the inductive shunts with little resistance. The problem is nearly the same also for ocean telephony; the difference is, that for common telephony various frequencies must be transmitted without distortion. The ocean telephony with aid of high-frequency currents on improved cables is already a solved possibility. For connecting continental circuits strong current microphones, more sensitive receivers, improved single-wire loaded circuits and telephone relays can be applied, which remove every limit of ocean and transcontinental telephony.
