WIRELESS SIGNALLING.

Hawera Star, Volume XLVIII, 13 September 1924, Page 13

WIRELESS SIGNALLING.

THE BEAM METHOD

In the beam method of wireless signalling a reflector is used which is parabolic in a horizontal plane and is formed of straight, vertical wires. This acts just as the parabolic mirror of a searchlight, which sends the beam in one direction and does not allow it to spread. The 6ize of the reflector must approximate to the length of the wavelength Hence, owing to oonstructural difficulties, effect of wind-pressure, etc., it becomes necessary to yrork with short wave-lengths. Long distance signalling has hitherto been done by the use of waves ranging from three to 15 miles in wave-length. The new system will entail the use of waves of a wave-length of about 100 yards. It has hitherto been supposed that such waves are readily absorbed and >vould not travel halfway round the wprld. Marconi recently showed that telephony was possible between Britain and Austriilia, using these short wave--lengths. In fact, it is thought that at certain portions of the 24 hours the messages would come via Suez when the darkness was on that side of the earth, 'and at other times via America when that route was on the side away from the sun.

It is of interest to know (says the Otago Daily Times) that some amateurs in Dunedin picked up signals on 87-metres wave-lengths which had come from Pans. The signals were heard at about 5.30 p.m. The French are evidently experimenting with these short wave-lengths, so that we may soon hear of considerable developments in the. use of this hitherto unexplored region of the wireless spectrum. There is great need Tor investigation of these effects. A short time ago the short waves were despised and were given to the amateurs. The amateurs showed that things could be done with these rejects that had been thought to be impossible. Here is, then, an example of the importance of allowing amateurs to investigate in this new and very absorbing field of wireless telegraphy and telephony. In the James Forrest lecture on Electrical Progress'and Its Unsolved Problems,” which Professor Elihu Thomson delivered in London at the Institution of Civil Engineers, the lecturer reviewed recent advances in electrical knowledge and practice, and, in concluding, asked: Who is there to tell us of the momentous issues and events which may arise out of the studies in pure science, of atomic and molecular structure, and the energy relations involved, which has become in large measure the chief study in physical science of our day? Perhaps our comparatively feeble beginnings in thermionic emission and the manipulation, so to speak, of electric ions, infinitesimally small though they he, coupled with the knowledge of the electric structure of matter in all its forms, may be the foundation of a greater or super-science of electricity of enormous importance to the future achievements. May we not hone through such work to reach the solution of many problems, as, for example, the direct production of electric current energy from the rays of the sun, by some form of absorbing ionic vacuum apparatus, and thus add greatly to the habitable areas of the world?