Dwina

Dwina, the name of two important rivers of Russia.—(1) The Northern Dwina has its origin in the confluence of the Suchona and the Jug, two streams rising in the south of the government of Vologda, and uniting in 60° 46' N. lat., 46° 20' E. long. The Dwina flows generally north-west through a flat country, to the Gulf of Archangel, which it enters by three principal mouths, of which only the easternmost is useful for navigation. The length of the Dwina is about 450 miles (with the Suchona, 760); its basin embraces over 140,000 sq. m. Its chief tributaries are, on the left, the Vaga and Emiza, and on the right the Pincga and the Vytchegda, the last having a course of some 625 miles, 500 being navigable. The volume of water poured down by this main tributary increases the breadth of the Dwina from about one-third to nearly two-thirds of a mile; near Archangel it widens to over four miles. The river is free from ice from May to October, and is a valuable channel of inland trade. Its waters also are rich in fish.—(2) The Western Dwina (Ger. Düna) rises in the government of Tver, not far from the sources of the Volga and the Dnieper, and flows at first WSW. in a course almost parallel to the latter stream. From Vitebsk it flows WNW. to the Gulf of Riga, which it enters after a course of about 580 miles, navigable from the confluence of the Mezha downwards, although the numerous shallows and rapids greatly impede traffic. Its basin is estimated at 32,850 sq. m.; its average depth of 26 feet at Riga is increased to about 40, and its breadth of 1400-2400 feet is extended in some places to a mile during the heavy spring floods which overflow wide tracts of the low-lying lands on either bank. The Western Dwina is connected with the Dnieper, and so with the Black Sea by the Beresina Canal, and by other canal systems with the Caspian Sea, and with the Neva and Gulf of Finland, &c.