The arrangements of the mansions and palaces found in the great cities were a good deal influenced by the circumstance that it was customary, in order to secure as much cool air as possible, to devote one of the upper floors to the purpose of a suite of reception rooms; to this was given the name of _piano nobile_. _Walls, Towers, Columns._ Walls are usually thick and stand unbuttressed, and rarely have such slopes and diminutions of apparent thickness towards their upper part as are not uncommon in England. Base mouldings are not universal. The cornice, on the other hand, is far more cared for, and is made much more conspicuous than with us. In the brick buildings especially it attains great development. Above the cornice a kind of ornamental parapet, bearing some resemblance to battlements, is common. The strikingly peculiar use of materials of different colours in alternate courses, or in panels, to decorate the wall surfaces, has already been referred to. It is very characteristic of the style. The campanile or bell-tower of an Italian church is a feature very different from western towers. It is never placed over the crossing of nave and aisles and rarely forms an essential part of the church, often being quite detached and not seldom placed at an angle with the walls of the main building. Such towers are not unfrequently appended to palaces, and are sometimes (_e.g._ at Venice) erected alone. Some of the Italian cities were also remarkable for strong towers erected in the city itself as fortresses by the heads of influential families. Many of these are still standing in Bologna. The smaller towers in which northern architects took so much delight are almost unknown in Italy, though on a few of the great churches of the north (_e.g._ the Certosa at Pavia, and St. Antonio at Padua) they are to be found. The use of constructive columns is general; piers are by no means unknown, but fine shafts of marble meet the eye frequently in Italian churches. The constant use of the column for decorative purposes is a marked characteristic. Not only is it employed where French and English architects used it, as in the jambs of doorways, but it constantly replaces the mullion in traceried windows. It is employed as an ornament at the angles of buildings to take off the harshness of a sharp corner, and it is introduced in many unexpected and often picturesque situations. Twisted, knotted, and otherwise carved and ornamental shafts are not unfrequently made use of in columns that serve purely decorative purposes. _Openings and Arches._ The constructive arches in Italian Gothic buildings are, as a rule, pointed, but it is remarkable that at every period round and pointed arches are indiscriminately employed for doors and windows, both being constantly met with in the same building.