It is interesting to watch how Byzantine architecture gave place to Gothic when Venice began to conquer on the Italian mainland. Thus Gothic architecture came in, and the conquest of Padua and Verona completed it. The term "Gothic" is very elastic; but there are certain points by which one can tell whether a building is Gothic or not. It is Gothic if the roof rises in a steep gable high above the walls; if the principal windows and doors have pointed arches and gables; if it has a steep roof; if the arches are foliated--that is to say, if the shapes of different leaves are cut into the stone to form a species of delicate tracery like lacework, letting in the daylight. Foliation is especially characteristic of Gothic architecture; some of the windows in Westminster Abbey are foliated. Gothic architecture is very rough and loose and irregular; yet it has a wonderful tenderness and variation of design. Changeableness and variety are the great requirements of perfect architecture. One should be enabled to derive just as much pleasure and instruction from looking at a perfect piece of architecture as from reading one of the finest of classic books. Gothic architecture is essentially truthful and naturalistic. The architects of this period were peculiarly fond of vegetation, which is a sign of gentleness and refinement of mind. Gothic is principally independent. It juts out continually with many pinnacles; there is nothing broad, or uniform, or smooth, about a Gothic building; it is variable, rough, and jutting, though, nevertheless, graceful in the extreme. The materials were rougher then than in the time of the Byzantine architecture, and to atone for this it was necessary to introduce much workmanship. [Illustration: PANORAMA SEEN FROM ST. MARK'S BASIN] The artists were enthusiastic in their love of Nature, and felt deeply all her changing and complex moods. For example, you may see the difference between a Renaissance and a Gothic palace by imagining the surroundings of the former, its background, gone. It would then be deprived of its charm; whereas if you took a Gothic palace and placed it anywhere, it would still be beautiful.