The nature of water: pipe width and the height it rises
Pressed cisterns in which a thousand pounds acts on but one pound of water
Under the heading 'The nature of water,' Leonardo states a hydrostatic proportion: for equal pipes rising from cisterns (bottini) pressed by equal weights, the heights the water reaches stand in the same ratio as the widths of the cisterns. In his definition the first pipe's bore fits 1000 times across its cistern, so a thousand pounds of pressing weight raises only one pound of water; a second pipe fitting ten times across raises a tenth, 100 pounds lifting 100 pounds. Two basins each lettered 1000 are drawn at the top with a rising pipe and a spout. A large pair of meshing toothed wheels is drawn below, without accompanying transcription.
On this page
Pipe-to-cistern width fixes how high water rises
For equal pipes rising from cisterns pressed by equal weights, the heights of the waters stand in the same proportion as the widths of the opposed cisterns. The two basins at the head, each marked 1000, set out the case.
A thousand pounds bears on one pound of water
If a pipe's bore fits 1000 times across its cistern, only one pound of the pressing weight benefits it, so a thousand pounds has power over just one pound of water; a bore fitting ten times across draws a tenth, 100 pounds raising 100 pounds.
Twin meshing toothed wheels
Below the water study a large pair of intermeshing toothed wheels on a vertical shaft is drawn; the bundle carries no transcription for this mechanism.