ONLY HALF OF LIGHTNING FLASH IS SEEN BY OBSERVERS
Not many years ago, a thunderstorm often meant that the supply of electricity would be interrupted. But now, lightning does not cause power line failures nearly as frequently as it used to; it has been tamed by engineers.
Laboratory artificial power lines that duplicate actual conditions in the field and huge generators with which to give them lightning-like charges have been important tools in the conquest of lightning. Scientists have learned that when lightning strikes a line, it produces two separate discharges. The first is a flashover, which endures only a few millionths of a second and makes a path for the escape of power to the ground.
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The power flashover endures from one-fifth to one-half of a second before the relays and circuit breakers clear the line, according to H.W. Tenney of the Westinghouse Electric and Manufacturing Company. Consequently, this is what the eye sees.
A photograph of a discharge across a string of insulators reveals the first flash as an escape of electricity resembling the dripping of a white, pasty substance over the insulators. The second discharge appears more powerful and elaborate and can be blown into striking designs, such as the one on the front cover.
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“FOSSIL NIAGARAS” DWARF EARTH’S GREATEST WATERFALLS
Two “fossil Niagaras” that would make the mightiest waterfall now on Earth a puny trickle by comparison, once roared in the Grand Coulee, a deep, wide gorge that lies about halfway between Spokane and Seattle. These extinct cataracts, now represented only by lines of towering cliffs, have been studied by Prof. J. Harlen Bretz of the University of Chicago, who has presented his report on them to the American Geographical Society.
The water that fed these two great cataracts came from melting glaciers of the great Ice Age. Creeping down from the north, the ice had for ages blocked the course of the Columbia River. As the glaciers began to melt off and retreat, they released immense quantities of water, which had to find a new watercourse. Of this necessity of nature was born the Grand Coulee, whose bed, now dry except for a chain of small lakes, is a thousand feet deep, with a width of a mile at its narrowest point. It has a total length of about 50 miles, with an interruption in the cliff walls somewhat more than halfway down its course dividing it into an Upper and a Lower Coulee.
ACETIC ACID MADE DIRECT FROM WOOD
A new method of producing acetic acid direct from wood without first producing acetate of lime has been used successfully in a chemical plant in Memphis, Tenn., and has just been introduced into the plant of an associated interest in Crossett, Ark., Emerson P. Poste has reported to the American Chemical Society.
The process, which was devised by a Viennese chemist, Hermann Suida, is hailed as wresting victory from defeat for the wood distillation industry, which has been so hard hit by the development of synthetic methanol and synthetic acetic acid.