Herisau , a town of Switzerland, capital of the half canton of Appenzell Outer Rhodes, 7 m. N. W. of Appenzell, on the right bank of the Glatt, about 2,500 ft. above the sea, pop. in 1870, 9,736. It consists of two principal squares and four streets, with seven smaller ones opening into them, and contains a large and handsome church, with a tower supposed to have been built in the 7th century, a new and elegant town house, a poorhouse, arsenal, and casino. There are extensive manufactures of muslins, plain and embroidered, and of cottons and silks, tanneries, dye works, bleach fields, and paper mills. The environs are laid out in beautiful walks and gardens, and the surrounding heights are crowned by the old castles of Rosenberg, Rosenburg, and Schwane-berg, while the baths of Heinrichsbad are about a mile distant. - Herisau was originally called Herginis Au. The Romans made a settlement here and Christianity was introduced early in the 7th century. The nobles of Herisau established their jurisdiction here, which in 1390 fell under the abbey of St. Gall. The abbot taxed the people heavily and arbitrarily, and in 1463 they bought themselves free.