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If the river m n, an affluant of the river Loire, were turned with its muddy waters, into the river of Romorantin, this would fatten
the land which it would water and would render the country fertile to supply food to the inhabitants, and would make navigable canals for mercantile purposes.
The way in which the river in its flow should scour its own channel.
By the ninth of the third; the more rapid it is, the more it wears away its channel; and, by the converse proposition, the slower the water the more it deposits that which renders it turbid.
And let the sluice be movable like the one I arranged in Friuli 593 , where when one sluice was opened the water which passed through it dug out the bottom. Therefore when the rivers are flooded, the sluices of the mills ought to be opened in order that the whole course of the river may pass through falls to each mill; there should be many in order to give a greater impetus, and so all the river will be scoured. And below the site of each of the two mills there may be one of the said sluice falls; one of them may be placed below each mill.
253:593 19: This passage reveals to us the fact that Leonardo had visited the country of Friuli and that he had stayed there for some time. Nothing whatever was known of this previously.