Motion Picture Herald (May-Jun 1946)

The Standard RICHARDSON'S BLUEBOOK of PROJECTION SEVENTH EDITION "You can do no better than get Richardson's Bluehook as a basis of instruction in projection."— George E. Hunt, projectionist and teacher. Rocky Mount, Va. This standard textbook on motion picture projection and sound reproduction brings up-to-the-minute guidance to projectionists and all others concerned with 35-mm. pictures. Additionally, the Seventh Edition contains four chapters on Theatre Television, prepared for the practical instruction of nnotion picture projectionists. The chapters on sound now include one devoted to control-track and stereophonic reproduction. And supplementing the regular text are 20 charts for handy reference in locating and correcting sound system defects. Each chapter is preceded by a list of study questions with cross-reference to the text so that the answers may be readily found. The text is thoroughly indexed for easy access to all instructions. $7-25 M Posfpaid QUICLEY BOOKSHOP 1270 Sixth Ave., New York 20, N. Y. as near as possible to the projection room, not only to reduce the cost of running wires and conduits, and to prevent excessive voltagedrop in the d. c. circuits, but also to prevent the possibility of any noise produced by the equipment from reaching the auditorium. Make sure that the roof will properly support the load of the housing plus the generator rheostats, starters and mounting bases. Metal housing,'6x6 feet square and 6 feet high, with one generator and the Electrical work should be always in accordance with established electrical code regulations. All wiring from the d. c. panel in the projection room, to the rheostats and generator, should be run in rigid, approved conduit, and terminate in approved outlet boxes or fittings. The rheostat connections from the conduit outlet to the terminal posts should be made with rubber insulated wires covered over with either asbestos sleeving or asbestos tape. In this way there will be less likelihood of the METAL SMELF KHSOSTA T — ^ □I &-0 /V//V. TO DC fAN£l d y^^cs A MSTAl FAM WOOD TO /='asHjy/)r/OA/ Recommended ins+alla+ion of motor-generator set and ballast-arc-rheostats on roof. auxiliary equipment will weigh about 1,600 pounds ; with two generators, around 2,300 pounds. The method of installing the equipment should always be consistent with standard practices. The shelf for the ballast arc rheostats should always be of fireproof material, such as metal or transite-asbestos, sturdily and rigidly held in place. A strong base should be installed under the generator to hold it constantly in a level, even position and to help spread the weight over the roof boards. It is a good idea to install a metal drip pan between the feet of the generator and the base into which any leaking oil or grease from the bearing housings will be caught, otherwise it will be a fire hazard. insulation around the wires breaking down from the heat of the rheostats. All rigid conduit runs to the generator and motor should terminate at least 6 inches above the roof with proper connectors installed for attaching small pieces of flexible Greenfield conduits. These flex-conduits are a necessity as they not only help reduce the strain on the wiring and conduits transmitted by the vibration of the generator, but also make it easier to have good connections and splices when the conduit wires are "out-of-line" with the connecting boxes. A little more money spent on a wellplanned installation will almost guarantee efficient operation of the equipment, year in and year out, if there is systematic main 44 BETTER THEATRES, JUNE I, 1946