More successful are many of the German theatres and concert halls, in which Renaissance and classic forms have been freely used. In several of these the attempt has been made to express by the external form the curvilinear plan of the auditorium, as in the +Dresden Theatre+, by _Semper_ (1841; Fig. 213), the theatre at Carlsruhe, by Hübsch, and the double winter-summer +Victoria Theatre+, at Berlin, by _Titz_. But the practical and æsthetic difficulties involved in this treatment have caused its general abandonment. The +Opera House+ at Vienna, by _Siccardsburg_ and _Van der Null_ (1861-69), is rectangular in its masses, and but for a certain triviality of detail would rank among the most successful buildings of its kind. The new +Burgtheater+ in the same city is a more elaborately ornate structure in Renaissance style, somewhat florid and overdone. [Illustration: FIG. 213.--THEATRE AT DRESDEN.] Modern German architecture is at its best in academic and residential buildings. The +Bauschule+, at Berlin, by Schinkel, in which brick is used in a rational and dignified design without the orders; the Polytechnic School, at Zürich, by Semper; university buildings, and especially buildings for technical instruction, at Carlsruhe, Stuttgart, Strasburg, Vienna, and other cities, show a monumental treatment of the exterior and of the general distribution, combined with a careful study of practical requirements. In administrative buildings the Germans have hardly been as successful; and the new +Parliament House+, at Berlin, by _Wallot_, in spite of its splendor and costliness, is heavy and unsatisfactory in detail. The larger cities, especially Berlin, contain many excellent examples of house architecture, mostly in the Renaissance style, sufficiently monumental in design, though usually, like most German work, inclined to heaviness of detail. The too free use of stucco in imitation of stone is also open to criticism. [Illustration: FIG. 214.--BLOCK OF DWELLINGS (MARIE-THERESIENHOF), VIENNA.]