NEW WONDERS OF SCIENCE

Evening Star, Issue 19796, 21 February 1928, Page 12

NEW WONDERS OF SCIENCE

RADIO TELEVISION PROVED COMBINED SEEING AND HEARING [From our own Correspondent.} SAN FRANCISCO, January 25. Radio television, another eighth wonder of science in this modern age of wonders, was successfully demonstrated at Schenectady in the State of New York, where radio television was proved to mean synchronisation of sound and light, transmitted through space by waves—air waves or ether waves. This exhibition signified that the may soon expect that when it twirls the dials it will see and hear the singers, fiddlers, and other artists whose voices have filled the air these past few years. The experiment was conducted by the Radio Corporation of America and the General Electric Company from the latter's laboratories in Schenectady. The pictures flashed on the television screen were so life-like that the smoke from a cigarette, and even the flash of the eye, wero transmitted to sets in three homes. The home television set is about the size of an ordinary phonograph cabinet, and television was made on a wave length of 37.8 metres, while the voice was transmitted simultaneously on 379.5 metres. HISTORICAL EVENT. The receiver differs from the ordinary short wave in that it converts an electro-magnetic wave into light instead of sound, and the light becomes an imago corresponding in movement to the action of the person at the transmitting end. Sitting in comfortable chairs in three widely-separated homes in Schenectady, several miles from the company’s broadcasting studio, tlie visitors were enabled both to hear and see the studio programme. Simple twists of the dials on the home television sets brought to rhese men the minute reproduction of the characters who appeared before t'' microphone. The sound of the voices was heard in the usual way through a loud speaker supplementing the visual apparatus. The climax of many years of labor in the laboratories of the company, these tests demonstrated the principal value of television as a means of entertainment in the home, as well as opening the path to endless possibilities in the world of commerce.

“While this is a historical event, comparable to the early experiments in sound broadcasting,” David Sarnoff, vice-president and general manager of the Radio Corporation, declared, “ the greatest significance of the present demonstration is in the fact that the radio art has bridged the gap between the laboratory and the home by a simplified and less elaborate and costly apparatus for television reception.” There are still many experimental stages to be travelled before television can bo established, ho said, the first of which contemplates placing laboratory models of the present receiver at central strategically-located points in order to aid technically-trained observers in future experiment. “Tlie television receiver will supplement, not supplant, the radio receiver,” Mr Saranoff said. RELATIVE SIMPLICITY.

The relative simplicity of the instruments used in the television broadcasting first was explained in detail to the visitors by Dr Alexanderson, who was introduced as the man chiefly responsible for the development of the now ar'-.

At the Alexanderson Laboratory the visitors were shown tho sending set, where horizontal waves of light, resembling the shadow bands familiar to those who have seen a solar eclipse, played over the face of the speaker. The successive spots or rays of light thus projected on the subject through the moving disc, wore intercepted by photo-electric cells, which converted the light into electro-radio waves, for transmission to the receiving sets. The radio engineers explained that the ele-' merits of tho receiving set are the light source, the scanning disc and the synchronising system. The official explanation of this was as follows:—“The signal, or electro-magnetic wave from the television transmitter is received in equipment designed to receive modulations as high as 40,000 cycles. The receiving system differs from the modern loud speaker in that a neon gasfilled lamp is substituted for the speaker. The amplified current is delivered to tin's lamp, invented by Dr M'Farlan M.oore, wliich responds to the intensities of tlie current and gives fluctuations of tho light intensity just as a diaphragm of the loud speaker reproduces pulsations of tho air waves. The scanning disc is 24in in diameter, with forty-eight small holes, each hole thirty-five millimeters in diameter, and arranged in a spiralso that each of the forty-eight boles will pass each other and trace successive lines of the picture, completing or literally painting a picture in one revolution. There aro eighteen revolutions a,second, or 1,080 a minute. The original picture flashed is square, but it is enlarged by magnifying glasses to Jin square. The reproduced pictmo is pink. Synchronisation of tho scanning disc of the receiver with tho scanning disc of the receiver with the scanning disc of tho transmitter is obtained by manuallyoperated control, a push button held in the hand.” BANK CHEQUES BY RADIO. Radio of the immediate future holds possibilities undreamed of a few years ago, O. Ham Caldwell, United States Federal Radio Commissioner, of Washington, told the House Appropriations Committee in tho national capital, during the recent hearings just made public Ho said broadcasting is almost insignificant in comparison with other radio prospects which the Commission is facing. Bank cheques will be sent, by radio within tho near future, as will facsimile' messages. Department stores will use radio for chain-store operation. Firo alarms will be sounded by radio; railways will use radio for operating trains, and oil and raining companies will use tlie radio to keep in communication with their distant properties. The newspapers are coming to us for wave lengths; our future aeroplane development depends entirely upon radio. The railways want wave lengths for talking from the trains, and even for talking from the caboose to the locomotive.. The intorurban bus people are asking ns for wave lengths for the purpose of despatching the buses along the highways and communicating with them so tliat they can be operated like trains. Oil, mining, and lumber companies want radio for communicating with their properties away up in the mountains or in the hills. The police and firo authorities are coming to us for wave lengths for police and fire alarms.