Show radio waves were picked up on a receiver in the laboratory and reproduced before their eyes it was the worlds first demonstration of radio movies and possibly the most astound ing of the many advances in the ance of radio announced during the past year while radio movies are still in the laboratory stage westinghouse boffl clagg noder whose auspices the dem was made declare that the event heralds the day when the radio listener will sit at home and have that most popular form of entertainment motion pictures projected by his indi vidual radio receiving set the development of radio movies Is a triumph of scientific engineering during the last summer the idea came to the mind of dr frank conrad in charge of this branch of his compi nys activities and the fact that in irely birely b two months he brought the device to the laboratory in the degree of perfection witnessed at the recent dem Is said to have set a fcc ord radio movies are a step beyond previous developments in television and required the invention of a num her of appliances in addition to a great deal of scientific calculation synchronism of various high speed mechanisms and accurate control of light and radio waves although the sending of moving pictures by radio as may well be imag ined required many complicated and delicate pieces of apparatus the pran caples of the art as explained by west In ghouse engineers are not beyond ordinary comprehension photography in ats simplest form consists of the reproducing of spots of light and shad ow in the same arrangement as they appear in the subject photographed the screening of a motion picture of course requires that a roll of film be operated at a depeel which sends sixteen a leond before a projecting beam of light because of the structure of the human ee if a series of pictures follow each other at the rate of sixteen or more per second the human eye sees it a a single loov ing picture all this the broadcasting of radio movies requires with alie addition that the spots of light roust be runs formed into frequencies some of which are in the audible range trans berred to a radio wave and broadcast as electrical energy in receiving the pictures the process Is reversed the electrical energy Is picked up and the frequencies returned to lights and which when viewed presents the radio movie in the first step of the process a pencil of light traverses web picture 1 the heart of tho television motion picture transmitter the scanning disc Is clearly shown as well as the dot of light which Is thrown upon the motion picture film above the scanning disc may be seen the syn tube which keeps this disc turning at a predetermined speed 2 dr frank conrad assistant chief engineer westinghouse electric and manufacturing company and inventor of the television motion picture pro jector the scanning disc of the ap Is immediately in front of him gi or frame as it is called at the ante of sixty times a sixteenth of a second this process produces a sixty line picture as clear as the usual newspaper halftone illustration the pencil of light Is produced by a scanner which Is a disc with a series of minute square holes near its rim the disc s EO arranged that all haht Is exclude ed from the film except that which poes through the square boles the disc turns very fast and as it turns pisses the beam of across each frame with the result that an andl vidual beam of light touches every part of the arime the beam of light passing through the film falls upon an electric eye or photo electric cell which Is not unlike an oversized incandescent lamp with in the cell however Is a metal whose electrical resistance varies with the light falling on it Cae seum a rare metal Is used in the westinghouse cell the amount of light falling on this cell determines the amount of current pissing through it the result Is tint each individual beam of hacht sends an electrical impulse which varies directly according to the amount of light or shade in the allm through which it passed the beams of light have now become electrical impulses and are sent on to the broadcasting station here lie heims assume definite and varied frequencies some of which are andl hie doctor conrad states that these frequencies range from somewhere near to approximately CO since he human ear Is limited to frequez cles of much of the radio movie wae Is inaudible at the broadcasting station these frequencies are transposed on a radio wave and transmitted exactly as the ordinary music or voice the signals now ain be sent across a roam or across tho continent their dl ange Is limited only by the broadcasting stations equipment in the demonstration the signals traversed a distance of about four miles two miles from the labora tory to the broadcasting station by wire and two miles back to the laboratory by radio to turn thee radio waves bade la to light an arrangement balch per alts the use of a mercury arc lamp Is used by this adaptation the weak radio currents control the action of the many times more powerful current operating the arc lamp this action may b compared to the action of a radio tube where the weak radio current on the grid of the tube controls the action of the independent and more powerful plate current thus the mercury arc lamp goei bright or dim as fast as the current changes and its light at any instant Is in prep to the light that the electric eye sees in the same instant to return the dots of light to their original pattern another disc or scanner Is also used which li similar to the transmitting scanner the use of a mercury arc lamp permits the radio pictures to be throan upon a ground glass or screen the first time this has been done with td apparatus both these scanning discs turn at exactly the same speed the hole la the receiving must be exactly la the same relative position as the corresponding hole in the disc in other words they mast be synchronized engineers were the first to develop a feasible method of synchronism and their method vii by means of radio from transmit ting equipment which may be located in the broadcasting station they transmit a constant frequency wave of 5 cycles this wave Is produced M a tuning fork and transmitted over special carrier wave from the broad casting station the constant t quency note Is receded on a receiver and by means of special apparatus controls the speed of art chr onous motors which drive tin scanning discs of both and receiving radio movie this revolutionary method of control ling equipment indicates in a isea ure the extent to which science ana go in order to perfect television w radio movies but the developments in radio wing the past year and especially farest development A w word impossible Is rapidly written out of the vocabulary american electrical engineering gea and that radio movies tor a H care to enjoy them are an 1 1 fact |