Machine to raise water by a bucket-wheel and lever
Lever and counter-lever calculations, wheel dimensions, and an underground channel to save the arcade
A large study for a machine to raise water: a bucket-wheel at the right is linked by a long lever, or beam, running left across a row of arches. Leonardo computes the balance of lever (640 parts) against counter-lever (20 parts), the weights carried, and the wheel's dimensions (5 braccia high, 6 thick), each bucket holding a square braccio of water. A lower sketch proposes leading the water through a buried channel instead of along the arcade, and a lettered figure keys the pipe (a), reservoirs (b, c) and channel (d f).
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Lever and counter-lever: 640 parts against 20
The lever runs 640 parts from the wheel's centre to its tip, against a counter-lever of 20 parts; a 1/20 rise of the counter-lever lets the lever fall 32 parts. Leonardo then balances the weights — counter-lever 442, lever 640, a surplus of 198 — and carries the load out to tens of thousands of pounds.
Underground channel replaces the row of arches
Instead of carrying the water along arches, the reservoir can be made only as wide and high as the wheel, and the water led through a buried channel to rise again at the tip of the lever by the last column. This saves the cost of all the arches between the wheel and that column.
Labelled water-raising scheme (a, b, c, d, f)
In the lettered figure a is the pipe from which the water rises, b is the reservoir that drives the water up into reservoir c, by way of the channel d f. The letters key the drawing of the wheel, beam and reservoirs at the foot of the sheet.