A WONDERFUL INVENTION.

Hawera Star, Volume XLVIII, 31 December 1924, Page 9

A WONDERFUL INVENTION.

TALKING PICTURES. SUCCESSFULLY TRIED AT * STRATFORD. A wonderful (invention which gives every promise of revolutionising the present motion (picture '’ world was successfully tried out 'in Stratford last night. The new machine produces the ordinary film stories on the seven, but from “loud speakers” on each side come the ' voices of the artists and the instrumental music.

Mr. W. P. /Kirkwood, of Stratford, has purchased the Australasian rights of the new invention, and last night MV. L. Rowson, of Hawera, erected The electrical equipment in a theatre .in tlie above-mentioned town, being assisted by Messrs.- Ward and Milne. Mhen the work of erection had been completed the first demon strati oh in Australasia was heard, and the result may be termed most successful and the effect absolutely natural. The synchronism, voice modulation, and volume of sound were all that could be desired. Tlie machine itself from outward appearances is more or less simple to look at, -and may be attached to any picture projector. The ' amplifiers, however, are very intricate, and' are practically the same as used on highpowered radio set®, but' at the same time the whole thing' is very compact and is in . .portable form. Special films are provided for the machine, and-, when the artists are performing their voices and the instrumental frequencies are’ impressed on a narrow strip on the edge of the film. This, when put through the projector is reproduced in its exact intonation, modulation, and all varying characteristics. The method by which this is accomplished is :as follows : The attachment or (phonofilm reproducer has at one end a, small highpowered lamp in a. tube-like container. This lamp is focussed through a- very small aperture directly on to the edge of the film whereon the voice frequencies are impressed. These light rays : penertate the .film in' die ret proportion to the voice de.nsity or frequency that has been impressed oh the film in the making. These light rays after passing through the film are in turn concentrated on to a eelindum cell, which,’ in appearance,' is very like a wireless receiving tube. This cell has the peculiar. properties of being affected by light, and when, a light is fqeyssed upon it allows it to pass a certain amount of current, and this current in turn is dependent upon the amount of light that has passed through the film. We now see that the vibrations that have been printed on the film are converted into an electric current, the same as produced by .the ordinary telephone. It is simply a matter now of reproducing or converting this current hack to' the voice frequency and amplifying them to their correct density. This is done first by a preliminary amplifier containing two vacuum tubes with a pressure of 66 volts impressed upon the plates. This amplifier clears up any discrepancy, after which it is passed into the main power ainplinor, brought nn to its required voliime, and distributed over the theatre by means of two large, loud speakers, similar to those used in wireless, only of a much larger type. * There is no doubt that the new machine ranks as one of the foremost inventions of the present day, and it will be interesting to watch how its commercial growth progresses.