Page:Popular Science Monthly Volume 89.djvu/64

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��Popular Science MnufhJif

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���The wind which is customarily ob- served is tli.it in- dicated by the fly at the masthead. The fly generally shows the skipper the apparent di- rection in which the wind is blow- ing. Professor Everett made ex- periments in a wind tunnel which show that yachts- men do not fully appreciate the mechanical forces at work

��The apparent wind is the result- nnt of the speed '<( the boat and ihc true wind

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