5,500-MILES.

Thames Star, Volume LVII, Issue 14728, 5 August 1921, Page 2

5,500-MILES.

TELEPHONE WONDER.

LINK TO OVERSEAS HOMSS

A special correspondent of the Daily Mail recently had the unique privilege at Washington of sharing in a conversation which opens a new era in the history of telephony.

From an armchair in the -PanAmerican Union Building, Washington, he_ cables, I exchanged greetings with an acquaintance in Havana, Cuba j and with a radio operator in Catalina, the picturesque island in the Pacific off Los Angeles. As plainly as though we were all seated in the same room I heard Havana speaking to Catalina and Catalina answering. It was by far the longest telephonic talk ever held. The message to which I listened passed through 115 miles of deep-sea cable connecting Havana and Key West, in Florida, thence over land wires connecting the chief towns of the Atlantic ' seaboard with New York, Chicago, Omaha, Salt Lake City, Sacramento, San Francisco*, Fresno City, and Los Angeles, and ftora Los Angeles by wireless to Catalina, 29 miles from the mainland. The total distance was 5561 miles.

During the afternoon President Harding had a telephone talk over the new deep-sea cable with President Menocal, of Cuba, and members of the* United States .Cabinet' with members of the Cuban Cabinet.

Colonel John J. Carty, vice-presi-dent and chief engineer of the American Telephone and Telegraph Company, to whose genius and organising ability the demonstration owes its success, afterwards said to me that the conversations, given the same telephonic equipment, s might just as easily have been conducted between London and Calcutta, via Paris, Constantinople, and Bombay. EXPERT’S PREDICTION. Colonel Carty predicts that in the not distant future telephony will prove a most potent agency in the consolidation of the British Empire and the unification of English-speak-ing peoples. He tells me that if deep-sea cable* and wireless were eliminated these conversations could have been heard with. exactly the same clearness over 10,000 miles of land wires, weighing 435 pounds per mile, equipped with telephone repeaters, and other apparatus used in the United States.

This means, he (says —and he speaks with deliberation and responsibility as perhaps the greatest living expert in the science of telephony—that it is possible to-day. given the equipment this country possesses, for London to talk with Capetown, with Calcutta, or even with Hongkong and Peking, via Calcutta.

Almost unimaginable political consequences to the British Empire, he thinks, are destined to arise from this, for the telegraph submarine cable, merely connects places, whereas the telephone ,connects peoples, and homes, and the time is quickly coming when the Government in London will be able to hold daily telephonic conversations with the Governments of the Dominions and India!.

BOON TO THE EMPIRE

The Et. Hon. F. G. Kelleway, Britain’s new Postmaster-General, then in the middle of his election campaign at Bedford, after reauing the Daily Mail cablegram reporting the 5500 mile talk, said he considered the test of immense value to the British Empire. “This new invention,” he stated, “opens out very wide possibilities. To be able to speak with Melbourne, Calcutta, or Ottawa by telephone direct would be one of the most effective ways of overcoming the difficulties from which we suffer, owing to the miles of sea and land separating us.” RELAY TELEPHONES. The secret of- the telephone conversations over more than 5000 miles in the United States is due to the success of the valve amplifier, which has done so much to improve wireless telephony. The currents received at the end of long-distance lines are greatiy attenuated, but the thermionic valve acts like a telegraph relay and picks up, as it were, these feeble currents and converts them into further cur-’ rents of considerable power, winch are passed on to the next section ct the long-distance lines. Thus waenever a telephone current becomes too feeble, as was explained to a Daily Mail correspondent by Mr. A. A. Campbell Swinton, the prominent electrical engineer, they are enforced by means of the valve relay, which is inserted every 200 or 300 miles.