International projectionist (Nov-Dec 1933)

22 INTERNATIONAL PROJECTIONIST November 1933 of from 30 to 250 photographs per second and records time in minutes, seconds and hundredths of a second. Type 2, equipped with the ultra high speed camera, has a speed range from 30 to 3,000 photographs per second and records time in seconds and thousandths of a second. Readings may be made down to one ten-thousandths of a second. The camera is of the continuous type, uses standard 16mm. film and is electrically driven, affording continuous operation up to 200 feet of film. It may be used on any tripod, and can be moved and tilted in any position while in operation. No difficulty is experienced in providing enough light for good film exposure, even when the camera is operated at top speed. Pictures have been taken indoors with a single 500-watt lamp which possess fine detail and photographic quality. Time Recording Apparatus The time is recorded by a precision electric clock driven by a current generator which consists of an electrically actuated tuning fork. The fork's amplitude of vibration is kept well within the elastic limits of the steel of which it is constructed. The temperature of the fork is controlled with a thermostatic element built in the fork which is housed in an insulated chamber to minimize heat losses and to guard against quick temperature changes. In temperatures from about 40 to 90 degrees fahrenheit, the current has a cycle precision of better than one part in 100,000. The Cine Timer has distinct advantages over stroboscopic light methods in that a permanent record is available and a record of non-recurrent or transient phenomena is made possible. Pictures of luminous objects and objects out-of-doors may also be made. Graphite Anodes a Feature of Sylvania Tubes A NODES or plates of pure graphite are the distinguishing feature of the entire line of Sylvania low-power, intermediate and high-power air-cooled transmitting tubes. A process developed in the Hygrade-Sylvania laboratories at Clifton, N. J., produces a one-piece anode of pure graphite, with all amorphous carbon and other impurities removed. This exclusive treatment insures freedom from harmful carbon deposits on filament, insulator and presses experienced with ordinary "carbon plate" tubes. Several Major Advantages In the present tubes the graphite plate is machined out of a solid block of carbon and subsequently treated before mounting. Ruggedly supported and bolted in position, the graphite plate will not warp or vary the tube characteristics irrespective of operating temperature or age or rough handling. Several major advantages are claimed for the graphite anode tube over the usual metallic plate tube. First, a 50 per cent greater heat dissipation due to the high thermal emissivity of graphite. This means the ability to handle greater overloads when necessary, or normal loads without overheating, or again smaller tubes if desired. Second, a lower operating temperature at the anode means lower operating temperature of other electrodes, preventing primary and secondary emission from the grid. Third, remarkable uniformity of characteristics, for graphite does not warp under high temperatures. The one-piece construction eliminates high-contact resistance found in other forms of construction. Fourth, long life and comparative freedom from gas. The tube remains "hard" or at high vacuum, throughout service life, because the graphite anode is a "getter". Originally introduced by Sylvania and tested in larger air-cooled tubes, the graphite plates are now being incorporated in all Sylvania air-cooled transmitting tubes. What is Back Of The Christmas Seal? Dwight Anderson Each year INTERNATIONAL PROJECTIONIST is glad to open its columns to the National Tuberculosis Association, the splendid work of which organization is financed by the sale of Christmas Seals. Many projectionists have experienced the beneficence of this organization, have learned of the great power exerted by the tiny Seal. This year the need is greater than ever; and so too will be the satisfaction of those who can afford to buy Christmas Seals. — Editor. T^ URN over in your hand the little Christmas Seal, and what do you find? Glue. That is there to make it stick. As Josh Billings said of the postage stamp, it "sticks to one thing until it gets there." In the last few years, when everybody lost faith in something, and some people lost faith in everything, the little Christmas Seal stuck. It stuck to the job of discovering cases of tuberculosis early enough to help them, of preventing the disease from going from the sick to the well, of building up resistance among children, and among grown-ups who were needy. The disaster of disease was not to be added to the distress of poverty. The Christmas Seal stuck because the people of the United States were willing to tax themselves voluntarily to pay for community health. Some people, forced to take their exemptions, could not pay this tax. Others, because of diminished income, paid less. Most people stepped right up to the window and contributed their bit just as before, and there were those who doubled the amount. Nobody evaded the tax. Nobody could evade a tax which he himself imposed. There is a great deal back of the Christmas Seal besides glue, that makes it stick. For one thing, people know that the death rate from tuberculosis is going down — that it has gone down despite hard times — and yet that the battle is not won when the disease still fills to capacity 398 public sanatoria in the United States, and more people die of it in the first decade of maturity than from any other ailment. People know that for 26 years the Christmas Seal has financed much of this struggle. Great progress has been made. But everybody realizes that when a runner comes in sight of his goal is just the time to speed up instead of slowing down. The goal of the Christmas Seal is ultimate elimination of tuberculosis. Now is the time to give it increasing support. And people know, too, that in their own communities certain definite and specific things are done with the money raised; that local persons whose probity is unquestioned, have charge of the disbursement of funds; that this is done with the advice and skilled help of the leading health authorities of the country, outstanding experts with many years of successful experience to their credit. These people who sponsor the seal sale in 2,084 associations and committees are the important factor back of the Christmas Seal. And back of them are the achievements of the last quarter of a century, plain on the face of the record. No man, no institution, stands alone. We want to know of a man, who it is that is back of him; we want to know of an institution, who and what is back of it. Because almost everybody knows this about the Christmas Seal, it sticks, and will continue to stick through weather, fair or foul, until at last it gets there. When this happens, tuberculosis will become a disease to be found only in the libraries of medical science. Buy Xmas Seals