Labels:text | tree | outdoor OCR: As a hydraulic engineer, Leonardo encouraged the use of dams and weirs to diminish friction where water meets soil. `"Frequent dams ought to be made transversally to the torrent so as to slow down the impetus; and these dams are made very thick to reduce the waterfall and avoid the digging out of the bottom where the fall occurs." (6r) When the descent from the weirs has been so hollowed out that at the end of its drop it is below the riverbed, then the waters which descend from them will never produce a cavity at the foot of the weir, and will not carry away soil in their rebound. If the lowest part of a weir which lies diagonally across the course of the waters be constructed in deep broad steps after the manner of a staircase, the waters which ... are accustomed to fall perpendicularly ...
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