Danube
a celebrated river of Europe, originates in two small streams rising in the Schwarzwald, or Black Forest, in Baden, and uniting at Donaueschingen. The direct distance from source to mouth of the Danube is about 1,000 miles, and its total length, including windings, about 1,670 miles.
From its source the Danube flows in a N. E. direction to Ulm, in Württemberg, where it becomes navigable for vessels of 100 tons; then to Ratisbon, in Bavaria, where it becomes navigable for steamers. Here it turns in a S. E. direction, entering Austria at Passau, passing Vienna and Budapest, above which latter town it suddenly turns due S., holding this direction till it is joined by the Drave, after which it runs S. S. E. and enters Servia at Belgrade. Continuing its general course E., it forms for a long distance the boundary line between Rumania and Bulgaria. At Silistria it once more turns N., and flowing between Rumania and Bessarabia falls into the Black Sea by three different outlets. In DANVILLE the upper part of its course, through Württemburg and Bavaria, the Danube flows through some of the most fertile and populous districts of its basin. Its principal affluents here are the Iser and Lech.
In Austria it passes through a succession of picturesque scenery till past Vienna, the land on both sides being well peopled and cultivated. The principal affluents are the March, or Morawa, and the Enns. After passing through what is called the Carpathian Gate, at Pressburg, where it enters Hungary, it gives off a number of branches, forming a labyrinth of islands known as Schütten, but on emerging it flows uninterruptedly S. through wide plains interspersed with pools, marshes, and sandy wastes. The principal affluents here are the Save, the Drave, and the Theiss. Sixty miles before entering Rumania the river passes through a succession of rapids or cataracts which it has made in cutting a passage for itself through the cross chain of hills which connect the Carpathian Mountains with the Alps. The last of these cataracts, at Old Orsova, is called the Iron Gate. The lower course of the Danube, in Rumania and Bulgaria, is through a flat and marshy tract, fertile but badly cultivated and thinly peopled.
In this part it increases its width from 1,400 to 2,100 yards, and latterly forms an expanse like a sea, and is studded with islands. Of the three outlets the Sulina Mouth is the deepest, and is usually chosen by ships bound up the river. The Danube is navigable for steamers up to Regensburg (Ratisbon), nearly 1,500 miles from its mouth. Some of its tributaries, such as the Save, the Theiss, and the Drave, are also navigable, so that the water system of the Danube may be estimated as a as admitting of about 2,500 miles of steam navigation.