Word: schonland
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Dates: during 1930-1939
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...used a special fast camera of a type previously used by Dr. B. F. J. Schonland, ingenious lightning observer of the University of the Witwatersrand in South Africa. Some years ago Dr. Schonland found that in a typical lightning flash a "leader stroke" starts from a negatively charged cloud toward the positively charged earth. The leader comes down by steps, dying out after each step, diving about 200 ft. farther with the next. Often 30 or 40 steps may be necessary before the ground is reached, but the whole descent occurs in 1/100 sec. or less. When the stepped leader...
...positively charged Earth; the main stroke traces the leader's path in the opposite direction. New photographs with a special speed camera show the leader stroke varying in length from 1.6 to 4.7 miles, in speed from 810 to 19,000 miles per second.-Dr. B. F. J. Schonland, University of Capetown...
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