The Cordova daily times., 1923-02-17
EXPLOSIVE GAS TESTS TO FIX
 FIRE HAZARDS

CHICAGO, Feb. IT. - Preparations are being made by the Fire Underwrit- CTS Laboratories, Ltd, here for the most exhaustive tests ever conducted to determine the fire danger from ex- plosive gas mixtures.
 Hundreds of pieces of specially de- signed apparatus are being assembled and during this month the tests will be started, with mixtures of hydrogen and air. ethyl and methyl chloride and air, ordinary gasoline and air! "cas- ing head' or so-called "wild" gaso- line and air; natural gas and air, and similar bases.
 As a result of the tests the labor atory engineers expect to develop new information covering the handling of dangerous gases, and new designs to insure safety of the portable contain CTS in which they are shipped.
 Because of the immense pressures developed in the various experiments ranging as high as 16,O00 pounds to the square inch, pressure sufficient to sent a locomotive through the air special appliances had to be de- signed.
 One, nickel steel bomb built out of navy armor plate at the Bethlehem Steel Works, weighs so many hundred pounds, although the gas chamber is only four by eight inches, that it was necessary to install a special hoist to handle the cover alone. Because of the harness of the steel and it's immense tensile strength, special tools were built for cutting it.
 The problem of photographing ex- plosion flashes travelling at a speed of 10000 feet a second required the development of special photographic films, as no existing film was sensi- tive enough to record light travelling at such tremendous speeds.
 The explosion chamber for the pho tographic tests is steel tube four inches in inside diameter and ten feet long, surrounded by thick hardened steel walls. At either end a narrow slit two inches long, is covered with "a thick quartzite lens, communicating with periscope attachment which in turn conveys the light to specially built cameras.
 hn Inn of hn r1n nJn- posite each other, are formed by a motor driven cylinders, two feet in diameter, driven at speed of 1700 revolutions a minute. Around the cyl finder is wound the photographic film. Travelling at such high speed the more than six feet of film passes before the camera at speed in excess of 17,200 feet or approximately two miles minute.
 In action the explosion flash, as it becomes visible at the nearest edge of the slit in the steel cylinder, will be reflected on one dge of the wide film. As it travels across the slit, it will print a corresponding line across photographs, and knowing the speed at which the film revolves. A cor responding photograph will be made when the flash passes the slit in the other end of the tube, ten feet away. By measuring the angles of the two photographs, and knowin gthe speed of the film, it will be possible to cal culate the speed of the flash. The result will show how rapidly and how far fire caused by an explosion of the gas under test would spread in factory building.
 To determine the exact speed of the cylinder carrying the photographic film, an ingenous device has been built. A second cylinder, carrying similar film, is mounted above the first, on the same axle. Nearby tun- ing fork, calibrated to vibrate at fixed rate, carries small mirror, which reflects beam of light on the second film. By counting the waves in the photograph of this beam, caused by the vibrations of the fork, it is possible to determine the speed at which the cylinder and film were travelling.