AN IMPERIAL CHAIN.

Dominion, Volume 6, Issue 1740, 3 May 1913, Page 5

AN IMPERIAL CHAIN.

BY WIRELESS.

CONCISE REPORT ON RIVAL SYSTEMS.

By Teloirrasli—Prcas Ansociatlon-CopyriEht (Rec. May 2, 10.10. p.m.) London, May 2. The committee sent by the PostmasterGeneral to report on the Poulscil system of wireless telegraphy, stato that it is practicable for short .distances, but that the Marconi system is at present tho only system of which it can bo said, with any certainty, that; it is capablo of fulfilling tho requirements of an Imperial chain. This must not be regarded as implying that tho Marconi Company must necessarily ),e employed as contractors for all the work of tho Imperial chain. Wireless telegraphy is in a condition of development; hence in tho construction and equipment of tho stations it is not desirablo that tho Post Office should be pledged to the continued use of any apparatus of any so-called system. On tiio other hand, it is imperative that it should reservo oomplete liberty of action.

Tho committee report that despite invitations thcro wero no demonstrations on a commercial scale, and in no caso was a distance of even a thonsnnd utiles obtained except by tho MarcDni. Tho latter was working over 2300 miles, from Clifden Island to Glace Bay, Nova Scotia, on' a commercial scale.

The committee say that from Clifden the transmission is sixty words per minute, whioh, if necessary, might bo considerably exceeded. Tho communication was practically continuous, but tlierO were occasional periods when tho signals were weak or suspended, owing to natural, conditions. Communication was only obtainable by great power in tho aerial from hero, and owing to tho increased power required for high-speed transmission, tho Marconi Company proposed to apply to Imperial stations double tho power employed at Clifden.

Even then tho cominitteo anticipate that there will be periods of stoppage, especially in tropical regions.

The practicalness of .the. Teleftinken system on a, commercial scale over distances of two thousand miles had not been proved, but the results of tiio present expei'iipmts with tho system over tho four thousand i miles between Naneh arid Togo indicate that communication is possible at night.

If tlio Poulsen system is to bo made commercially practicable over distances of two thousand miles and upwards, tho bto must be so constructed as to supply tho aerial with higher power or a more sensitive receiver must be used.

The .Goldschmidt system,. Hanover, would similarly only Tequdro a powerful machine to make it of practical use over a long distance. The Poulsen and Goldschmidt systems .were admirably adapted for high-speed transmission.

Tho Post Office, tho committee hold, should, whatever the system adopted, insist on high powers for the Imperial cliAin. Perhaps in some respects it was desirable for tho Government themselves to construct and equip stations for the development of wireless telegraphy., This would probably involve the ultimate stlbstitution of high frequency generators, producing continuous oscillations, for those dependent on spark discharges, which produeo groups of oscillations. Tho Post Office should bo frcoi to employ or experiment in any development of wireless. There was no reason why, under a highly skilled engineer' and expert staff, tho Post Offico stations should not bo ultimately equipped with apparatus far more efficient than that now iised by.aqy socalled -System.