Dnieper, The, a river of Russia, anciently the Borysthenes. Next after the Volga and the Danube, it is the largest river in Europe. It rises in the Lake Mchara in the government of Smolensk, and flows S.W., S.E., and S.W. into the Black Sea. With a length of 1,230 miles, it is navigable to a little above Smolensk, and receives among other tributaries the Beresina, Desna, Pripet, and Psiol. The Oginski canal unites it with the Niemen, that of Horodetz with the Vistula, and that of Beresina with the Dnna. There are important fisheries in its lower course. Between Kiev and Alexandrovsk are a series of cataracts, which necessitate a portage of 30 miles, but these are in process of removal by blasting. A service of steamboats has existed since 1838, and there is much trade. The only bridge is at Kiev, and this is taken away during the-freezing up of the river in winter.