International projectionist (Jan-Dec 1947)

mize fluctuations in arc current produced by changes in arc gap length and in the gas envelope around the arc. When the arc is struck this same reactance limits the short-circuit inrush current within safe bounds. Primary taps are provided for line voltages from 190 to 240 a.c. Switching is provided for change in d.c. voltage in steps of 2 volts from 25 to 37 volts. Since there are no filaments, this combination of switching provides for any normal fluctuations in the power lines. A remote control panel is provided which can be located in any convenient place in the projection room. With this panel the projectionist can start and stop either rectifier, or switch the same rectifier from one lamp to the other. Section 'd Ljreetinai LOCAL NO. 171 Pittsburgh Penna. G' ?tit freeunad . . . Local No. 224 I.A.T.S.E. & M.P.M.O. of the U. S. and Canada Washington, D. C. ^rroliaau K-jreetinai LOCAL NO. 257 OTTAWA, ONT. CANADA LOCAL NO. 692 MARLIN-HEARNE TEXAS J. A. Elections LOCAL 273, NEW HAVEVN, CONN. A. M. Frazier, pres.; Maurice Moriarty, vice-pres.; Ernest De Gross, sec; Edwin Boppert, treas.; Matthew Kennedy, bus. agent; Louis La Vorgna and John Griffins, Jr., exec, board. MONTHLY CHAT {Continued from page 3) look for no further advances in this direction for quite some time to come. One has only to use the modern f:2 or f:1.9 projection lens to become acutely aware ot the magnificent job turned in by the optical fellows. On the television front, this department (and, we think, its readers too) are surfeited with the great gobs of material released to date relative to the iminency of theatre television. Home video is now entering a boom period, backed by a great merchandising campaign, but we see theatre tele no nearer to actuality than it was a year ago — or two years ago. True, a few theatres have installed experimental tele systems, but the problem of programming still has them licked. One of the surprise developments of the past year was the apparently successful effort of Russian technicians in producing three-dimensional motion pictures. IP, no less than other observers, was at first constrained to accept such reports with the usual dash of salt, the Soviet being noted for its agility in propagandizing the "wonders" of every facet of Russian life and accomplishment. The reports of impartial, trained observers, however, cast this Russian achievement in a wholly different light. Reports of the availability of worldwide rights to this Russian process make it certain that the leading American companies who are interested in this field will not long be without the know-how. This is all to the good for our film theatres. Certain other developments bearing on film production and reproduction are cooking at the moment, but on such a slow fire as to not warrant that which would be only idle speculation at the moment. The film industry, unlike its status in 1926 before sound pictures were handed (?) to it full-blown, is no longer just a business of glamor, ballyhoo and false front. The lack of a sound scientific program nearly proved disastrous in 1926, and this time the business has both hands up ready to defend its position on the technological front. In the setup of things motion picture, the projectionist still occupies a key position— one that will grow rather than diminish in importance. None of the developments of the past 20 years has shorn the craft of any of its prestige; rather have they enhanced the standing in the industry, and certainly they have emphasized the necessity for good craftsmanship and the continuing need to be alert and informed. For its part, IP has sought to meet this requirement for an informed craft, and the record of the past 16 years would seem to indicate that it has discharged this function quite well. In turn, the craft itself has extended unswerving reader loyalty and support to IP, thus making possible the job that has been done. This happy circumstance of mutual respect makes it very easy to say with the best grace in the world, "A Merry Christmas and Happy 1948." U. S. Releases German Sound Reproduction Techniques Reports by British Technical Intelligence reviewing the recording industry in Germany have been recently declassified and are now available from the Office of Technical Services of the U. S. Department of Commerce. Of greatest interests are details of the Tefi sound recording and reproducing system and the Neuman damping recorder, it is said. The Tefi system consists of recording on laterally-cut tracks on a flexible tape and reproducing by passing the tape under a needle held in a pickup. The Neuman damping recorder is an exceptionally simple and reliable device for the logarithmic recording of voltage values, being particularly suitable for electro-acoustic measurements. It is also used for determining voltage differences in sound frequency generators, such as microphones and receivers. Complete construction and operation instructions and schematics are included in the report. Other reports, released at the same time, include one on a universal condenser microphone, believed to be the first single transducer, uni-directional microphone to be made and a report on filter designs for communications systems developed by the Siemens-Halske Laboratories. * * • PROJECTIONISTS LOCAL No. 650 I. A. T. S. E. WESTCHESTER COUNTY, NEW YORK 38 INTERNATIONAL PROJECTIONIST December 1947