WIRELESS TELEGRAPHY

Dominion, Volume 10, Issue 3094, 26 May 1917, Page 8

WIRELESS TELEGRAPHY

AN/INTERESTING LECTURE.

'At the Officers' ■• Institute, Buckle Street, last evening a very interesting and instructive lecture on wireless telegraphy was delivered by. Mr. A. Scott, chief electrician to the General Post Office. Colonel G. ]?. C. Campbell presided, and there was a good attendance of officers. Mr. Scott explained tie elementary principles of electricity,' and fully and clearly explained the relations of electricity to magnetism, and led up to what was the foundation of wireless. He illustrated tho analogy between sea waves, sound waves, and electric waves, and explained that long waves ond short waves were the basis of the Morse code.' In sea waves' ho demonstrated that it was the energy and not the medium that travelled. A stone dropped.into water caused an agitation in. tho water, and the energy so created travelled, and not tho water. Pressure.waves were explained, and their varying velocity, which depend upon the density of the medium. Air waves or wireless waves were then explained. In a wireless station it was necessary to have- an alternating current of high frequency, aiul this necessitated the use of many instruments. He showed how the current was .sent into the air to causo the wireless waves, and then illustrated, how the waves were caught at ihe receiving station. Tho tuning of stations was illustrated; it depended on the wave length; a station might be working on a 2000-metre length alongside of others of, say, COO metres ami 1800 metres without jamming. With a nortable Tolcfunkwi wireless apparatus ho showed in n practical way how tho I wireless waves were sent and received.

On the motion of fhe chairman a, hearty vote of thanks was accorded the lecturer. '

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A notice to property owners and farmers is inserted in this issuo by. Mr. R. G. Nathan, 115 Quay. Tho notice .c-hould be of special interest to those persons who are about, to disnoso of their properties. Two freehold farms or the Manawatu Lino are Advertised for sale by Messrs. Dalgcty and Co., i Wellington. Tho larger consists of 1500 acres, and is situated near Otafci. tho smaller farm has an. area, of 247 acres and is also near town.