a river of Germany, rises in Württemberg, near the borders of Baden, in the Black Forest, not far from the source of the Danube. It flows in an irregular course, first N.E., traversing the N.W. corner of Hohenzollern, then N. through Württemberg, and finally nearly W. through Baden, to the Rhine, which it joins at Mannheim. Its principal affluents are the Enz, on the left side, and the Kocher and Jagst, on the right. The towns of Rothenberg, Tübingen, Esslingen, Heilbronn, and Heidelberg stand on its banks; and those of Stuttgart and Louisburg are in its vicinity. The whole length of the river is about 270 miles, and it is navigable as far up as Cannstadt, 120 miles from its union with the Rhine.