Live Articles on Special Hazards Volume 6; A Series of Articles Reprinted from the Monthly Fire Insurance Supplement of the Weekly Underwriter ... (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 Excerpt: ...points should receive ample protection. All wiring should be conveyed in metal conduits wherever practicable. The incandescent lights over the machines and benches should be protected by wire guards. In many well-arranged houses the lights for the entire theater are controlled by switchboards in the operator's booths. These should be of an approved type, and they should be mounted on marble bases and have all their parts well insulated. It is also advisable to have them covered by enclosures provided with hinged doors having spring catches. Careless operators sometimes bridge the terminals of fuses with copper wires after the regular fuses have burned out. This should not be permitted, but a supply of fuses should be kept on hand at all times for emergency purposes. Cartridge or plug fuses should be used in connection with switchboards, and those of the open type should be avoided. RESISTANCE COILS. The resistance coils (which are used for regulating the current supplied to the arc lamp) should be encased, and should be mounted on some sort of fireproof material that is properly insulated. The wiring should be such that the temperature will not exceed 400 Fahrenheit. Films. Standard-size films are-ii inches wide and about two onethousandths of an inch thick, and there are sixteen pictures to each foot of film. Along each edge there are 64 perforations (known as sprocket holes) to each foot of film, and the film in its travel through the machine head is impelled by sprocket wheels, the teeth of which engage in these holes. To obtain good results, the film should travel past the projecting aperture of the machine at the rate of about one foot per second. This means that there are sixteen pictures projected upon the screen every second. There are various kinds...