WIRELESS TELEGRAPHY

Evening Star, Issue 15174, 3 May 1913, Page 5

WIRELESS TELEGRAPHY

BRITISH COMMITTEE’S REPORT. RIVAL SYSTEMS COMPARED. Press Association.—By Telegraph—Copyright. LONDON, May 2. The Postmaster-General’s committee of experts report that the Poulsen system of wireless is practicable for short distances, but the Marconi is at present the only system which can be said with any degree of certainty to be capable of fulfilling the requirements of an Imperial chain. This statement, however, must not be regarded as implying that the Marconi system must necessarily be employed as contractors for all the work of the Imperial chain. Wireless is in a condition of development; hence in the construction and equipment of stations it is not desirable that the Post Office should be pledged to the continued use of any apparatus or of any socalled system. It is thus imperative to reserve complete liberty of action. Despite invitations, no demonstrations were made on a. commercial scale, nor was a distance of even 1,000 miles obtained except by the Marconi system, the latter working 2,300 miles—from Clifden (Canada) _to Glace Bay (Ireland) —on a commercial scale. In the Clifden transmission 60 words were sent per minute, which, if necessary, might be .considerably exceeded. Communication was practically continuous, but there were occasional periods when the signals were weak or were suspended owing to natural conditions. Com•munication was obtainable only by great power in the aerial, owing to the increased power required for a high speed of transmission. Mr Marconi proposes to apply to the Imperial stations double the power employed at Clifden, but even then the committee anticipate periods of stoppage, especially in tropical regions. The practicability of the Telefunken system on a commercial scale over 2,000 miles was not proved. The results of the present experiments over 4,000 miles, between Nauen and Togo, indicate that communication is possible at night. ' If the Poulsen system is to be made commercially practicable over 2,000 miles and upwards the arc must be so constructed as to supply an aerial with higher power, or a more sensitive receiver must be used. Similarly-, the Goldschmidt ' system (Hanover) would only require a powerful machine to make it practicable over a long distance. The Poulsen and Goldschmidt systems were admirably adapted for high-speed transmission. Whatever system is adopted, the Post Office should insist on high* power for the projected Impeiiai chain. Perhaps in some iaspects it is desirable that the Government themselves should construct and equip these stations. Tire development of wireless probably revolve *,he ultimate substitution of high frequenev generators, producing c,intiuu,.us oscillations ior those dependent spark lisci.arges whicu produce groups of oscillations. The I *st Office should be free to emplov or experiment with any development -.f wireless 1 here was no reason whv, under a highjy-skilled engineer and an expert staff, the Post Office stations should not be ultimately equipped with apparatus far more efficient than that now used by any so-called system.