Supports, walls, and foundations
Allied to the basic simplicity of action of the column is (as with the arch and dome) a natural expressiveness that has been exploited architecturally not only in the Classical orders but also, for instance, in the soaring piers of the Gothic cathedral and in some of the best modern work in steel and reinforced concrete. The wall, being less naturally expressive, has been treated in a more varied manner. Sometimes its structural role has been emphasized by the application of columns or pilasters to the otherwise unbroken surface, or by giving an exaggerated emphasis to the massiveness of the masonry. At others it has been played down further by covering the surface with an insubstantial sheath of thin marble slabs or making it serve as a field for painted, mosaic, or relief decorations. But at all times the structural development has been directed chiefly to ensuring the necessary strength and stability economically with the means available. Foundations, being always out of sight, have of course always been designed solely to play their purely utilitarian role as efficiently and economically as possible.