The Arno Diversion: River Bends and Water-Mills
Sketches of the Arno's bends and a projected canal, a pile-driver, and a list of water-powered machines and workshops.
Sketches and notes concern the taming of the river Arno: its bends 'always grow until the swift currents are dammed back into three waves', a barrage with the reminder to 'watch the bank', and a plan to straighten the Arno above and below to gain a treasure per unit of land. At the foot the meanders are shown crossed by a projected canal, and Leonardo blames the river's flooding on its failure to clear its waters past the tree-choked Gonfolina gorge. A central column lists water-powered machines and workshops — saws, fulling and paper mills, trip-hammers, grinding wheels, a spinning machine 'for 100 women', ribbon looms and lathes for jasper and porphyry — and a pile-driver with pulley is drawn separately. Small geometric figures and a note on staircases sit at the top.
On this page
The bends of the Arno and its swift currents
The bends of rivers always grow until the swift currents are dammed back into three waves. In the upper right the meandering course of the Arno is drawn, with a barrage at the centre and the reminder to 'watch the bank'.
A list of water-powered machines and workshops
The central column lists mills and machines driven by water: saws, fulling mills, paper mills, trip-hammers, ordinary mills, knife-grinding wheels, machines for polishing arms and for grinding powder and saltpetre. It continues with a spinning machine 'for 100 women' in silk, a ribbon loom, and lathes for fine vessels of jasper and porphyry.
Straightening the Arno to win a treasure of land
The left column proposes to straighten the Arno both below and above. From this a treasure will be gained, at so much per staioro of reclaimed land, for whoever wants it.
Flooding blamed on the Gonfolina gorge
This Arno floods because it does not clear away its waters with the speed at which the upper Val d'Arno pours them in. And the Gonfolina gorge does not give them passage through its valley, obstructed by trees.
A pile-driver with pulley marked 'fixed'
A separate figure, drawn with the sheet turned, shows a pile-driver operated with a pulley. Part of it is annotated 'fixed' (stabile). It belongs with the engineering of the river works.
The Arno's meanders crossed by a projected canal
At the foot of the sheet the winding bends of the Arno are laid out as a topographic sketch, cut across by a projected straightening canal. The plan pairs with the note that the river cannot clear its waters through the Gonfolina.