Collier's New Encyclopedia (1921)/Loire
LOIRE (lwär), the longest river in France, rising in the Cévennes, in the department of Ardèche, at an elevation of 4,511 feet, flowing in a N. and N. W. direction through the center of France as far as Orléans, where it bends round to the S. W. and continues on to Tours; thence following, in general, a W. course to its embouchure in the Bay of Biscay. It is tidal to Nantes, 35 miles from its mouth; entire length, 620 miles. It becomes navigable a little above Roanne, 550 miles from the sea. The Loire is notorious for the destructive inundations it causes, though the lower part of its course is protected by large dykes or levès, 20 feet high. The principal tributaries are the Nièvre and the Maine (which is formed by the Sarthe, its affluent the Loir, and the Mayenne) on the right; and the Allier, Cher, Indre, and Vienne, on the left. The Loire is canalized along considerable stretches of its course, and is connected with the Seine, the Saône, and the harbor of Brest by canals. Its valley is extremely fertile. Area of drainage basin, 44,450 square miles.