Drying sea-bordering ponds with siphons and eddy machines
A horse-driven ship, sectioned vessels and siphons that carry pond water into a sea eddy
Leonardo continues his scheme for drying ponds that border the sea by means of artificial eddies. He asserts it is possible to make the water's surface lie lower than an eddy's own bottom, and illustrates the machinery: a horse-driven ship carrying gearworks to raise eddies, a sectioned vessel with a siphon and one-piece axle, and a siphon-and-vessel set between pond and sea. Lettered diagrams (a b c, e f d g, o m, a h and n m o p r) show a siphon leading pond water into a sea eddy dug twice as deep, and compare two siphon arrangements.
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Making the pool's surface lower than an eddy's bottom
Leonardo claims it is possible, within one and the same pool, to make the water's surface lie lower than the bottom of an eddy, and lower than the water striking another fall — the key to drying ponds that border the sea.
The benefit of drying sea-bordering ponds
A marginal note records the benefit of drying out the ponds that border the sea — the practical aim of the whole siphon-and-eddy apparatus.
Horse-driven ship with gearworks to raise eddies
A profile shows a ship (nave) carrying gearworks driven by four horses (4 cavagli) to produce artificial eddies.
Sectioned vessel with siphon and one-piece axle
A section shows the vessel with its siphon (cicognola) and an axle made of one piece (asse d'un pezzo) that spins the water into an eddy.
Siphon a b c d leading pond water into a sea eddy (e f d g)
The pond a o m n stands level with the neighbouring sea at a h; an accidental eddy e f d g is made twice as deep as a o, and the siphon a b c d, passing over the pond's bank, carries the water into the eddy's bottom.
Two siphon arrangements compared (n m o p r)
The siphon n m o p r works when the rock has a pole, as drawn; but the other arrangement is better, because there the falling water strikes the bottom and its motion also adds weight.