137. The forms of the villas to which these towers are attached are straggling, and varied by many crossing masses; but the great principle of simplicity is always kept in view; everything is square, and terminated by parallel lines; no tall chimneys, no conical roofs, no fantastic ornaments are ever admitted: the arch alone is allowed to relieve the stiffness of the general effect. This is introduced frequently, but not in the windows, which are either squares or double squares, at great distances from each other, set deeply into the walls and only adorned with broad flat borders. Where more light is required they are set moderately close, and protected by an outer line of arches, deep enough to keep the noonday sun from entering the rooms. These lines of arches cast soft shadows along the bright fronts, and are otherwise of great value. Their effect is pretty well seen in fig. 10; a piece which, while it has no distinguished beauty is yet pleasing by its entire simplicity; and peculiarly so, when we know that simplicity to have been chosen (some say, built) for its last and lonely habitation, by a mind of softest passion as of purest thought; and to have sheltered its silent old age among the blue and quiet hills, till it passed away like a deep lost melody from the earth, leaving a light of peace about the gray tomb at which the steps of those who pass by always falter, and around this deserted, and decaying, and calm habitation of the thoughts of the departed; Petrarch's, at Arqua. A more familiar instance of the application of these arches is the Villa of Mecaenas at Tivoli, though it is improperly styled a villa, being pretty well known to have been nothing but stables. 138. The buttress is the only remaining point worthy of notice. It prevails to a considerable extent among the villas of the south, being always broad and tall, and occasionally so frequent as to give the building, viewed laterally, a pyramidal and cumbrous effect. The most usual form is that of a simple sloped mass, terminating in the wall, without the slightest finishing, and rising at an angle of about 84 deg.. Sometimes it is perpendicular, sloped at the top into the wall; but it never has steps of increasing projection as it goes down. By observing the occurrence of these buttresses, an architect, who knew nothing of geology, might accurately determine the points of most energetic volcanic action in Italy; for their use is to protect the building from the injuries of earthquakes, the Italian having far too much good taste to use them, except in cases of extreme necessity. Thus, they are never found in North Italy, even in the fortresses. They begin to occur among the Apennines, south of Florence; they become more and more frequent and massy towards Rome; in the neighborhood of Naples they are huge and multitudinous, even the walls themselves being sometimes sloped; and the same state of things continues as we go south, on the coast of Calabria and Sicily.