by Marie Curie 
Da Vinci Notes 13: The River's Law and the Arno
Water runs fastest where the river is narrowest, and the same quantity passes every section. I learned it in a trough, and the Arno taught it to Florence at Pisa in 1504.
Leonardo's rule that a river runs faster where it narrows, the 1503 to 1504 plan with Machiavelli to divert the Arno from Pisa, why it failed, and his canal.
Leonardo da Vinci
November 8, 2026
30 min