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What Makes The Wind Blow: Encyclopedia Britannica, 1965, 800 feet in length, B&W, good condition (some light lines at times).
A series of laboratory experiments and some demonstration in the field give a fabulous overview of the forces that cause the wind to blow. One of the highlights is footage of a howling dust storm which was caused by a cold high pressure system over the interior of the continent. Some other highlights include: Several scenes of strong winds blowing during the intro; footage of a smoke bomb being set off at a beach which clearly shows the direction of the steady sea breeze blowing; an experiment which uses a glass box with a diaphragm to create different air pressures and wind; a segment which shows the barometric pressure at three places at the same time (on the beach, 20 miles offshore, and 20 miles inland) to explain why the sea breeze blows; an excellent laboratory experiment that explains why warm air rises and cold air sinks; an explanation of the role of the sun and temperatures in diurnal wind situations; and some footage from the Arctic which shows a totally frozen landscape and blowing snow. There is also an experiment in the film where they create wind in a glass box by placing a container of water on one side and soil on the other and then shining a heat lamp on it.
Buyer pays $4.50 for shipping. Foreign buyers, please inquire about shipping cost.
Thanks for looking!
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