Currents, Waves, and the Weight of Water
Six red-chalk and pen notes on wave motion and water pressure
Six red-chalk and pen notes, all on the behaviour and weight of moving water, illustrated with small diagrams of a hollowed river-bed, a wave striking a bank (a-b) and a draining vessel (a, n, m). Leonardo observes that water exceeding a river's general depth and width flows in a contrary motion, that a wave stands highest midway between the cause of its motion and its end, and that wind-driven surface water runs opposite to the water beneath. He adds that water weighs no less crosswise than vertically, and that the centre of a vessel's floor receives the greatest weight of water and drains fastest where the flow weighs most.
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Water above the river's general depth flows against the current
Leonardo notes that water which overpasses the general depth and breadth of rivers moves in a contrary motion. The remark is numbered 23 among his running water propositions.
Where the water-wave stands highest
A wave of water, he writes, will be highest between the cause of its motion and its end. The point is illustrated by a wave shown breaking against a bank, marked a and b.
Wind-driven surface, contrary motion below
Water moved by the undulation of the wind makes at the bottom a motion contrary to that of the surface. Leonardo pairs this with the claim that water weighs no less crosswise than along its perpendicular.
The centre of a vessel's floor bears the most water
Every liquid motion weighs most in the place from which, through an equal hole, its vessel empties fastest. The centre of the vessel's bottom (a, n, m) receives more of the water's weight than any other place.