Chia'na

Chia'na (ancient Clanis), a river of Central Italy, originally a tributary of the Tiber, watering the perfectly level Val di Chiana, which its overflow (see CHIUSI) rendered once the most pestilential district of Italy. The bed was deepened in 1789-1816, and in 1823 extensive hydraulic works were undertaken for further improving the river-course, and for leading a northern branch, through canals, to the river Arno, a few miles below Arezzo, the southern stream reaching the Tiber through the Paglia at Orvieto. The double stream is 60 miles long, and $\backslash frac\{1\}\{2\}$ to 1 mile broad; and the district has since become one of the most fruitful in all Italy.