Danube

One of the great rivers of s. Europe. Heads in the mountains of s. Germany, and flows generally s. e. acro Austro-Hungary, thence nearly e., serving as then. boundary of Servia and Bulgaria, to its mouth in the Black Sea, which it enters through a delta of 1,000 sq. m. Length 1,613 m., drainage area 299,435 sq. m. Its volume at its mouth is 200,000 cub. ft. per second. It is navigable below Ulm. It has 100 navigable tributaries, and is connected with the Rhine and the Elbe by canals. Since the Peace of Paris, 1856, it has been free to ships of all nations, and is controlled from the Sea to the Iron Gate, below Orsova, by an International Commi ion.