STREAMLINE TRAINS

New Zealand Herald, Volume LXXI, Issue 21716, 3 February 1934, Page 7 (Supplement)

STREAMLINE TRAINS

POSSIBLE ADVANTAGES An idea of the saving in airresistance which the streamlining ot trains might conceivably introduce is given by a writer in the Scientific American. At 40 miles an hour for an ordinary 200-ton train a total horsepower of 305 is required. Of this, journal and roll friction accounts for 30.6 per cent, flange action accounts for 35.7 per cent, and air resistance for 33.7 per cent, or, roughly, onethird of the whole. At 100 miles an hour the picture changes considerably. Now 2500 horsepower is required. Of this 9.3 per cent is in journal and roll friction, 27 per cent in flange action and 63.7 per cent in air resistance. The writer says: "The moral of these two sets of figures is clear. As the speed of the train becomes really high the air resistance is the predominating factor in the horsepower required. "Another comparison is of.interest. The air resistance of this hypothetical 200-ton train of ordinary design is 65001b. at 100 miles an hour. Were the train of the shape of a really good airplane fuselage of the same frontal area the air-resistance would be only 2251b. No wonder railroad people have finally turned to the possibilities of streamlining. " Aircraft operators view the idea of the streamline train with mixed feelings. Some saw in it a definite threat to the speed supremacy of the aircraft. We do not think there is such a threat. On long hauls the airplane, capable of cruising at 200 miles or more an hour, will always be infinitely superior to the fastest train from a time-saving point of view. On shorter hauls the streamline train will redress the balance in favour of the more old-fashioned method of transportation, for in short hauls the airplane is not at its best." BOTTLED HOUSEHOLD GAS A report from Germany says that, as a result of experiments, a supply of gas for a household will now be available by the bottle. Chemists have succeeded, it is stated, in so treating a byproduct obtained in the synthetic production of benzine that it can be stored in liquid form in steel bottle containers, each of which is supposed to contain about fifty cubic metres of gas. Its burning qualities, it is claimed, are such as to make it useful for lighting and cooking, for hot water supply and general purposes. The importance of the new chemical production, if reports are justified, can be readily understood, seeing that it would make possible the illumination of small centres of population without the expensive installations now necessary. All the benefit in lighting, heating and cooking now obtained from gas produced in the ordinary way would be secured, it is contended, at a very small cost by the new process. AUTOMATIC WATER TESTER Automatically testing water, a new instrument equipped with photo-electric cell keeps a check on the hardness of water. When the hardness exceeds a definite figure the device sounds an alarm. It is connected to the soft-water supply line, and at intervals a sample of water passes into a glass cylinder. A small quantity of chemical is mixed with the sample. If the water is zero hard no changes occur in the colour or turbidity of the sample. The slightest trace of hardness, however, causes a change. Then a beam of light is passed through the cylinder containing the sample to strike the photo-electric cell, which converts light into electricity, and the alarm is given. AID TO PHOTOGRAPHY Giving off nothing more terrifying than a spft glow, a new photographic flash bulb has been used as an aid to the cameraman, because his subject is not startled and the pose is better. The bulb is coated deep blue inside, reducing the brilliancy of the flash as seen by the subject, but having little effect on the film, which is sensitive to the peculiar blue light. Photographic work inside churches, court rooms and other places where use of the brilliant white flash bulb is inadvisable is now possible with the new blue bulb.