OCEAN CABLEGRAMS

Greymouth Evening Star, 12 November 1925, Page 2

OCEAN CABLEGRAMS

CHEAPER AND FASTER. An development of cable communication between Europe and the United States has been the increased. speed of signalling rendered possible by a new type of cable. In the line 'laid between the Azores and the United States which has recently been brought into service, the spee ( d of transmission has been raised from 300 letters per minute for the old type cable to'- ISOO letters per minute for the new continuously loaded line. New .alloys were used in the construction of this cable. It was pdinred out in a contribution by Mr Donald F, Campbell. to the meeting of the Iron and Steel Institute in Birmnig-

ham, that this achievement had givien an entirdly new aspect to the economics of submarine signalling, and. coupled with the reliability'and secrecy of this form of transmission, appeared to ensure a considerable demand for the remarkable series of alloys used in the manufacture of the cable. The process for production of the alloys on a commercial scale had been worked out during the research on high frequency melting of metals, conducted by the Telegraph Construction and Maintenance Company, and was therefore a British' achievement. The range of alloys produced 'contained from 50 per cent, to 74 per cent, of nickel, 20 to 25 per cent, of iron, some copper and niangane.se but no carbon. For some types of cable where high electrical insistence was required, an extra element, which might be tungsten, chromium, vanadium, titanium, or other alloy, was added. The largest installation of Irgh frequency electric welding furnaces had been established in Great Britain, and as a result more than 5000 mi'Jes of the new type of submarine cable would be laid wi~.ru the next few months. The gradual replacement of old cables by high speed lines should lead to a great reduction in the ocst of submarine cable messages.