A canton of North-West Switzerland, between Bern (W. and S.) and Aargau (E); is hilly, but fertile and well cultivated, especially in the valley of the Aar; inhabitants are mainly Catholics and German-speaking. Soleure, the capital, situated on the Aar, 18 m. NE. of Berne, has a fine cathedral, and manufactures of cottons, clocks, and cement.