TELEVISION

Wanganui Chronicle, Volume LXXXI, Issue 18973, 26 March 1924, Page 10

TELEVISION

AMATEUR SCIENTIST'S INVENTION. SECRET PLANS. OUTLINE OF OBJECTS TRANSMITTED. LONDON February 2. The possibility of Television—or seeing by wireless-—has tired the in ventive genius of amateur s all over the country. Yesterday a Daily News' representative visited the home of a young amateur scientist, Mr. J. L. Baird, who has succeeded iu transmitting the outline of objects on the lines of television. His method rcscmble s that of‘Mr C. F. Jenkins, the American inventor, as described in the Daily News, excepting that Mr. Jenkins uses a. revolving disc of prisms, while Air, Baird uses an ordinary slotted disc and selenium. Mr. Baird took me into his laboratory, writes the Daily News’ repersentative. He lives within five minutes’ walk of the station at Hastings, and he uses the drawing-room as his laboratory. A machine that appeared to comsist of two discs and a few cardboard boxe s occupied one table. On another were two wireless valve sets with numerous batteries. “The principle upon which my invention works,” said Mr. Baird, “is the turning of light into sound. The note the transmitting apparatus produces varies in accordance with the light aud shade of the picture. “Actually every part Of the picture is picked out and sent separately, but so slowly does the retina of the eye work compared with the speed of the machine, that the picture appears as a whole. “Every element of the picture is projected in succession upon a lightsensitive cell of selenium. This cell turns the note into‘an electric current, varying in intensity in proportion to the light and shade of the picture.” IN A CRUDE STATE. Mr. Baird then took me to his invention and explained its component parts. “It is very crude,” he apologised. A 2,000 candle-power light was burning in a brightly polished chamber of tin. The light from this passed through a condenser shining directly on the object be reduced. After that it passed through a perforated disc, which directs the light from each part of the picture in succession on to a selenium cell. The light is split, by a serrated dial revolving at a very high speed, so that differences of light and dark are produced at a very high frequency. “Light transformed into sound,” Mr. Baird explained, "gives a high note for light parts of the picture, a low note for a dull part, and silence for complete darkness: “Sound is thus turned into electrical energy, which may be sent out at will by wire or wireless in the ordinary way.

“At the receiving end the electric energy is, after amplification, used to light a lamp in the same way as at tho transmitting end. Both the transmission and receiving discs must revolve in synchronism.” Up to the present Mr. Baird has transmitted only outlines of simple figures. He is waiting to start on a more elaborate machine of which he already has plans. “The plans are secret, but I will tell you with the aid of my machine I am positive your editor at Fleet Street could see you talking to me here. Lookers-in in the north of England will be able to watch a football match at Wembley. DIFFICULTY OVERCOME. “What seems to you the great difficulty of synchronising the revolving of the slotted disc at the receiving and transmitting ends I have overcome. That, too, is my secret.” Mr. Baird set the shadow television machine in motion for me. The revolving dises were connected with the wireless transmitter, the current was switched on to the receiving set and lamp. Mr. Baird took a cross cut out in cardboard, placed it on the far side of the condenser and there, a couple of feet away, in a little dark chamber of cardboard, I saw the outline of the cross. We tried other outlines, letters, symbols, rulers. The result came clearly every time. There was no trickery about it. The reproduction appeared on the same disc as that from which it was transmitted, but on a different part. Mr. Baird has been unable to erect another disc in this home-made laboratory, but he is making a second to use at a public demonstration of his invention in a few weeks’ time. Mr. Baird already has apparatus ready to transmit by his bigger machine when completed detailed pictures like photographs, and not merely outlines on the silhouette principle.