Survey of the Nirone, with river and perspective notes
Planimetry of the Nirone watercourse; questions on currents and water-weight, and notes on aerial perspective
A faint planimetric survey of the Nirone watercourse runs across the right of the sheet, its curving line annotated with strings of measurements. The written columns pose questions on the science of waters: whether a narrowed channel diminishes the flow, whether river bends impede the current compared with a straight course, and which water weighs more in a bent right-angle conduit. Interleaved are painting notes on aerial perspective, on making a painting appear in relief, and a passage on cities destroyed by their rivers.
On this page
Planimetry of the Nirone watercourse
On the right of the sheet a planimetric survey of the Nirone is laid out as a curving line annotated with long strings of numerical measurements.
Questions on channels and river currents
A series of questions asks whether a channel narrowed in some part diminishes the flow and abundance of water at the end of its course, whether the windings of rivers impede the water's motion compared with a straight course, and whether a winding river covers as much ground as a straight one in the same time. It adds that where two waters rub together the sand forms a crest.
Aerial perspective: distant objects appear bluer
A note observes that at a remote distance an object which is of a darker color will show itself bluer.
The painter's art of making a picture appear in relief
Among the principal skills of the painter is to make his painting appear in relief, something that does not fall to the sculptor, who in that respect is aided by nature.
The utility of the science of waters
Leonardo argues that the science of water is useful because many chief cities set upon their principal rivers were consumed and destroyed by them, as Babylon was by the Tigris on account of Cyrus, and Micilate and Gazimba of the Parthians; the science of water gives precise knowledge of the defenses against them.
Weight of water in a bent conduit
Beside a right-angle tube lettered a, c, d, b, Leonardo asks which water weighs more, a in b or c in d, to show the variety of weights produced by one and the same water descending through bent conduits.