Worthen, William Ezra, 1819-1897, [from old catalog] ed · New York, Appleton · leaf 641
Fig. 1508. Fig. 1509. The direction of the air-currents within the house was determined by thistleballs, and the quantity, as found by anemometers, was about 15,000 cubic feetper minute. This amount, sufficient to ventilate the house, is that required toimpress the proper movement on its…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
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