Science: Radio Cinema

Frank Conrad, with no formal education, with no specialty, but with a roving curiosity and a knack of applying his learnings to electrical devices that has made him Westinghouse’s most valued technician, two months ago set out to assemble the first machine for broadcasting cinema. Last week at the Pittsburgh laboratories of Westinghouse Electric & Manufacturing Co. he made it work. Spectators, men potent in the broadcasting industry, saw and heard an airplane which had landed at Detroit last spring. They also heard the roar of its propeller and saw landing lights blink. Another Westinghouse invention, electrically sensitive to the propeller’s howl, had turned the lights on.

This new Conrad machine will probably be called Photophone, the present Westinghouse system of reproducing sound with pictures. Names suggested for the newer radio cinema have been: Frankon-radio, brema (broadcast cinema), cineradio.

The existence of Westinghouse’s radio business is due to Frank Conrad. In 1890 he went to work for the company as a handy boy. He has “butted in” with invention ideas so often that a great mass of Westinghouse’s inventions are in his name. The company lets him do as he pleases, quite as General Electric permitted the late Dr. Charles Steinmetz to do. Westinghouse engineers and research men always consult with him on their devices. The company’s present vast business of electrical measuring and metering instruments grew on his foundation work. So with its automobile equipment business; its radio work.

Before the War, when radio was awkwardly experimental, Frank Conrad discovered that Western Union’s time service was not absolutely accurate. He is an expert on the theory and construction of time pieces. Against his own watch he doubted Western Union time. So he built himself the radio receiving set to get Arlington time signals directly. Radio became his hobby. (Raising gold fish and studying low forms of animal life are others of this versatile man’s avocations.)

Soon on the upper floor of his garage, he had a radio station the equal of any in Pittsburgh. Then came Westinghouse’s broadcasting station KDKA.

Sending Machine. Cinema films consist of a series of small photographic negatives (“frames”) that flash upon the cinema screen for one-sixteenth of a second each. At that speed, the eye can receive them as a continuous, moving picture. Each frame pauses before the projecting machine light.

Another faculty of the eye is to accept as a whole picture a mass of dots (periodicals utilize the fact for their illustrations). In every square inch of newspaper pictures are 3,600 dots, thick and thin. TIME illustrations, better copies of original photographs, have 14,400 to the square inch.

Mr. Conrad takes advantage of both these eye traits.

Between the strong light and the moving film “frame” (which stops for the sixteenth of a second) he whirls a disk. Near the disk’s perimeter is a spiral of minute square holes. Sixty dots of light flash through them every sixteenth of a second. The flashes then go through the paused frame and strike upon a filament of glass-enclosed caesium. The caesium carries an electric current which the flashing light makes strong or weak according to the bright and dark places of the transilluminated film. Thus light effects become electrical effects. The caesium bulb becomes in effect a broadcasting microphone.

In his demonstration last week inventive Mr. Conrad sent his electrical current, thus modified, two miles by wire to another Westinghouse laboratory where broadcasting apparatus was in play and his electrified pictures came back to him by air. If two miles can be crossed in this way, so can the earth.

Receiving Machine is the reverse of the sending machine. Antennae pick up the proper radio waves. Instead of going through a radio bulb, they go through an arc light whose brilliancies they modify according to the varying transparencies of the sending film. The fluctuating arc light shines through a perforated, rotating disk upon a ground glass screen and the spectators on the other side of the screen can see their pictures.

Production. Westinghouse is already building several Conrad machines for receiving radio cinema. They are to be set up in different parts of the U. S. and in about two months KDKA will broadcast pictures for experiment. Later, machines will be sold generally through the Radio Corporation of America.