The international photographer (Jan-Dec 1936)

January, 7V.iV> T he INTERNATIONAL PHOTOGRAPHER Twenty A. Periodicals. 1. "Proceedings of the Institute of Radio Engineers,'' monthly, The Institute of Radio Engineers, 33 W. 39th St., New York City. Particularly the December 1933 and November 1934 issues $1.00 per copy to non-members). Membership in the organization can be secured by responsible interested persons. Dues vary from $3.00 to $15.00 per year depending upon the grade of membership. For information write to the Secretary at the above address. 2. "Electronics," monthly, McGraw-Hill, 330 W. 42nd St., New York City. B. Pamphlets. Cathode-ray Tubes and allied Types, Series TS-2, RCA Radiotron Division; RCA Mfg. Co., Harrison, N. J. (25c) C. Books. 1. "Radio Engineering Handbook," Henney, Second Edition, October 1935, McGraw-Hill. This one up-to-date volume gives more radio-television information than any other book. 2. "Television" Felix, McGraw-Hill. This gives the background and history of television and discusses the program, entertainment, and commercial aspects. 3. "Measurements in Radio Enginering," Terman, 1935, McGraw-Hill. This gives the measurement and laboratory technigue reguired by the prospective technical (Continued from Page 26) employee. Thirty-two experiments are found in the back of the book. 4. "Experimental Radio Engineering," Morecroft, Wiley, 440 4th Avenue, New York City. This contains fifty-two experiments, which comprise the book. 5. "Radio Operating Questions and Answers,'' Nilson and Hornung, Fifth Edition, McGraw-Hill. This book gives all the information required to pass any of the United States Government examinations for a television (or radio) station operators license. 6. "High Frequency Measurements," Hun, McGraw-Hill. This is an advanced work, giving valuable data on a wide variety of measurements and measuring technique. 7. "Photoelectric Phenomena," Hughes and DuBridge, McGraw-Hill. This advanced book on photoelectric cells furnishes excellent instruction for television research workers to do. 8. "Higher Mathematics for Engineers and Physicists," Sokolnikoff, McGraw-Hill. This is an advanced work intended to assist the research engineer in understanding the mathematics found in advanced books and in the advanced papers appearing in the "Proceedings of the Institute of Radio Engineers," and similar publications. 9. "Inventions, Patents, and Trade Marks," Wright, McGraw-Hill. This gives information on patent practices and is useful to either the executive or research worker. WHAT IS HOLDING UP TELEVISION? (Continued from Page 7) of the wires were under any great tension, but were given a natural period corresponding to the frequency at which they were intended to oscillate. He hastened to add: "The wires not being under a great tension, are not subject to crystalization or fatigue, hence have an extremely long life, at least longer than any radio set so far built." Also he said: "Being that a torsional form of vibration was employed, instead of a rotating-resolution, it could be kept under a positive control at the receiving set at all times by the master oscillator at the transmitting station." This, of course, is something that has not been approximated so far by any mechanical system of scanning. The overall dimensions of the unit occupies a space of two by five by eight inches and weighs about ten pounds. Incidentally, the manufacturing cost is said to be much lower than any system yet devised. Doctor De Forest's explanation and remarks regarding the optical light control, were also very interesting in their practical aspects. The modulation of the light which builds up the image on the screen by the flying spot is obtained by the electrical incoming variations acting upon polarized light. This light control principle is not new to television, but it has been greatly refined in recent years. It makes use of what is known as a Kerr cell, the operation of which is a beautiful example of the electro-magnetic nature of light. Its electro-static nature was first studied by Dr. Kerr, of Glasgow, Scotland, about 1854. Doctor De Forest was very assuring that these cells are now a practical article. They are absolutely without inertia and have no moving parts, are fool proof and have a low construction cost. The only replacement cost encountered is in the life of the projection lamp, which is around several thousand hours, and they may be purchased anywhere at a nominal price. However, to complete the decription of the scanning system, use is made of proper lenses to concentrate the light from a 200 watt projection lamp through the Kerr cell and on to a metal scanning mirror where it is reflected through an objectifying lens to sharpen the spot and then on to the screen. Consistent with what Doctor De Forest outlined in the beginning as practical television requirements, the amplifier employed by Mr. Priess is greatly in advance of the average television amplifier and it has been developed by him over a long period of years. Some of this work has been done by Mr. Priess while with the United States Government, especially in connection with what he calls an "untuned" amplifier. This amplifier has no peaks or any form ot emphasis throughout the entire television frequency range, which assures a perfect transmission of the image variations. Doctor De Forest concluded by saying that Mr. Priess had taken out patents in foreign countries as well as here and that he has exclusive rights in the United States on "untuned" amplifiers, which are to issue shortly, as property of the United States Government. The scanning system is also thoroughly protected here and abroad. Mr. Priess is now preparing to manufacture these sets at a low market price, within the reach of the average income. HEAD STILLMAN MARION IS BUSY Still Cameraman Art Marion has returned from location where he shot the stills for Buck Jones, starring in "Silver Spurs," Picture No. 10 of Universal release. Direction, Ray Taylor; Mike Eason, assistant director; Allan Thompson, first cameraman; Herb Kirkpatrick, operative cameraman; Edward Jones, assistant, first unit; Joe Lykens, assistant, second unit. In (AtarlJ-OOid* Us* prwltice C^^n li<gbr and Ni^bV Offsets in Daytim^'F^ Sc^n^sOif fuse*! F^ccis.arwl many vHicrvffvcts Witb any Camera " In any Climate GcorcjG H. ScHcibe ORIGINATOR OF EFFECT FILTERS 1927 WEST 78TH ST. LOS ANGELES, CAL Please mention The International Photographer when corresponding with advertisers.