Vistula (Ger. Weichsel, Polish Wisla), one of the chief rivers of Europe, rising in Austria and flowing first through Russian and then through Prussian territory. Its source is in Austrian Silesia on the northern slopes of the West Beskiden range of the Carpathian mountains.
The stream runs through a mountain valley, in a N.N.W. direction to Schwarzwasser, where it leaves the mountains, turns E. and N.E., and forms part of the Austro-German frontier. Returning within Austrian territory (Galicia), it passes Cracow, and thereafter forms a long stretch of the frontier with Russia (Poland), bending gradually towards the north, until at Zawichost it runs due N. and enters Poland. Here it at first bisects the high-lying plateau of southern Poland, but leaves this near Jozefow, and flows as far as the junction with the Pilica in a broad valley between wooded bluffs. Crossing the plain of central and northern Poland, it passes Warsaw, and at the junction of the Bug sweeps W. and N.W. to pass Plock and Wloclawek (see further Poland for its course within this territory). It enters Prussia 10 m. above Thorn, turns N.E. on receiving the Brahe, passes Graudenz and turns towards the north. From this point it throws off numerous branches and sweeps from side to side of a broad valley, having steep banks on the side upon which it impinges, and on the other being bordered by extensive flat lands. Nearing the Baltic Sea it forms a delta, dividing into two main arms, the left or western of which bears the name of Vistula, and flows directly to Danzig Bay, while the right is called the Nogat, and flows into the Frisches Haff. The enclosed deltaic tract is very fertile. Parts of it are known as Werder (cf. the English "islands" or "holms" in the Fens and other low-lying tracts of the east). In the lower part of the delta the Haff Canal leads from the main river to the Frisches Haff; there are also various natural channels in that direction, but the main river passes on towards the N.W., having a tendency to run parallel to the coast, and reaching Danzig Bay with a direct course only through an artificial cut constructed in 1888-96. The river broke a new channel into the bay, at a point between this cut and the old mouth at Neufahrwasser, on the night of the 1st-2nd of February 1840. The important seaport of Danzig, however, is on the old channel, and this channel is used by shipping, which enters it by a canal at Neufahrwasser. The Nogat, formerly inconsiderable, had become so much deepened and broadened by natural means in the early part of the 19th century that it carried more water than the Vistula itself (i.e. the other main deltaic branch). In 1845-57 the outflow of the Nogat was stopped and an artificial channel was formed for it, so as to restore the proper head of water to the Vistula.
Shafting banks form a serious impediment to navigation, and these and floods (principally in spring and midsummer) necessitate careful works of regulation. The river is ice-bound at Warsaw, on an average, from about the 10th of December to the 10th of March. The navigation of the Vistula is considerable up to Cracow, and the river forms a very important highway of commerce in Poland (q.v.) and Prussia. For small craft it is navigable above Cracow up to the Austro-German frontier, where the Przemsa enters it. This river and the Pilica, Bzura, Brahe, Schwarzwasser and Ferse are the chief left-bank tributaries; on the right the Vistula receives the Skawa, Raba, Dunajec, Wisloka and San before reaching Poland, the Wieprz and Bug in Poland, and the Drewenz in Prussia. The Brahe and the Bromberg Canal give access from the Vistula to the Netze and so to the Oder. The river is rich in fish. Its total length is about 650 m., and its drainage area approaches 74,000 sq. m.
See H. Keller, Memel-, Pregeland Weichselstrom, ihre Stromgebiete, &c., vols. iii. and iv. (Berlin, 1900).
