Does a bend in the race change the force that turns a mill?
Water courses drawn with and without a hump (gobbo) near the point of impact
Three pen diagrams at the top of the page show a channel or stream in section: one dipping down into a U, one running straight, and one interrupted by a raised hump in its bed. Below them Leonardo poses a question about the impetus of the water that turns mills, asking whether a hump in the channel — crosswise, up or down — near the point of impact would leave the striking force the same as if the water ran in a straight line. The note is written in mirror script.
On this page
Would a hump weaken the water's blow?
Leonardo asks whether the impetus of the water that turns a mill, if the channel were to make some hump (crosswise, up or down) near the place of impact, would be of the same force as if the water ran along a straight line. The question isolates the effect of a bend in the race on the driving blow of the water.
Channel profiles above the note
Three drawn profiles compare water courses: an upper channel dipping into a U, a straight run, and a course interrupted by a raised hump in its bed. They set out visually the alternatives named in the question about the mill's water.