Exhibitors Herald and Moving Picture World (Oct-Dec 1928)

42 BETTER THEATRES SECTION OF December 22, 1928 National Regulators Take the "And How" Out of Projection! Xational 30-30 Mazda, because of its absolute freedom from lium and other disturbances — is, where throw permits, the most adaptable projection for sound, known. This means that when you buy National Regulators you buy safely for the future. Call — wire — or write for a demonstration of National 30-30 Mazda — the low priced, high class projection that gives, D. C. results at A. C. cost. Descriptive matter will be furnished gladly, upon request. Sold and Serviced by, National Theatre Supply Company— Branches Manufactured by Carver Electric Company "The Busiest Place in The World" Mfrs. of Electrical Equipment since 1915 UNION CITY, INDIANA, U. S. A. Heat your Organ Chamber Correctly! The Prometheus Organ Heater protects the delicate mechanism of the organ by heating the lower part of the chamber in a scientific way. Unlike other devices which senoVheat upward, thus neglecting the equally important base, Prometheus deflects the warm air downward. The heat naturally rises throughout the organ chamher giving a constant, unvarying degree of temperature. Proper heating ;i\ <»i<U expensive repairs and maintenance co*t> due to destructive cold, moisture and climatic changes. It al-<> keeps pitch accurate. Automatic Thermostat regulates Ural tit the proper decree required. Furnished in Aluminum. Occupies only //'i v / inches. Sturdy. Durable. Send I lotipon for < onipli I'ROMKTIIKI S KI.KCTKIC COM'., 358 NX. 13lh Si„ I'll a-r M-nil detail about vour oif_'an lu alcr. te Detaill \ru X ork < ■ i -s \ I Ml tltlHll iSS Building the Auditorium (.Continued from page 10) quality of instruments and the voice, is the area just above the heads of the auditors. Elsewhere the sound should be absorbed. In general it may be said that the region of the auditorium where the sound is produced, should have mainly reflective qualities, the rest of the theatre being largely absorbent. Some theatres have been treated for reverberation with hangings and cloth wall coverings, etc., and in some cases this method has been overcome enough to make presentation of sound pictures possible. But in most instances, the exhibitor who is trusting this method to make his theatre a good place in which to hear synchronized pictures, may be fooling himself more than his patrons. From the point of view of acoustics only, the use of hangings and similar furnishings is to be rejected because such material absorbs a great deal more sound of the higher vibrations than those of the lower. * * * The heating and cooling of the auditorium has been reduced to such a science and has received such regulation through public health codes that it would seem that all the builder has to do is to follow a usual procedure. That, apparently, is what is done in many cases, yet 'the result is not always a happy one. A rather common ventilation fault in auditoriums is the lack of regulation for different states of occupancy. This is particularly to be found in the larger houses, seating over 1,500. At times when only the forward seats are occupied, the patron is often conscious of a severe draft coming from the rear, and since most people harbor certain fears of drafts, they are not only uncomfortable physically, but mentally as well. The human body serves as a heating apparatus, and thus the auditorium needs but comparatively little heating when practically all of the seats are filled. Engineers estimate that the heat given off by 3,000 people is equivalent to the amount given off by 1,500 square feet of steam radiation. Theatre heating systems, of course, are built with this fact in mind. But suppose there are not the people to give off this amount of heat? Regulation of the temperature should be through the ventilation system. In the upward type, which is generally found most satisfactory for the larger houses, fresh air "mushrooms" are placed beneath the seats. When the rear seats are empty, this fresh air continues to come through the ventilators, and there being no bodies to heat it, this cool air "flows" down the sloping floor toward the front seats, which are occupied, causing the disagreeable and dreaded draft. The difficulty is obvious : The chamber is so large that several kinds of conditions may exist at the same time. The exhibitor who wants to spend his money for the things that will make his theatre fundamentally right, will make every effort to install a ventilation system that is divided into units, each unit applying to a certain section of the auditorium — the forward part, the rear, under the balcony and in the balcony, mezzanine floor, and so on. Control can be made automatic, though the system can be operated manually as well. * * * The downward system of ventilation is also often guilty of causing drafts in unoccupied areas, the reason being that structurally it has not been possible to get the proper distribution of outlets over the entire floor. When there is this structural condition, it is better to place the outlets at the ceiling and have the system capable of introducing fresh air at a velocity great enough for the patrons to feel it in their faces. Like the upward