PLAN.—A plan may be familiarly described as an architectural _map_, or map of a building: therefore only those who cannot comprehend a geographical or topographical map—a degree of obtuseness hardly credible—can be at any loss to understand an architectural one, the latter being precisely of the same nature as the others, with this difference in its favour, that it is much less conventional. To define it more exactly,—a plan is a _horizontal section_ supposed to be taken on the level of the floor through the solid parts of the fabric—walls, columns, &c., so as to show their various thicknesses and situations, the dimensions of the several spaces or rooms, the position of the doors by which they communicate with each other, and various particulars that cannot otherwise be explained. Studying buildings without plans is like studying geography without maps. Nevertheless, most persons ignore—affect a genteel ignorance of such vulgar and technical drawings as plans. Plan frequently costs the Architect more study than all the rest of his design. Very much mistaken are they who suppose that convenience alone has chiefly to be considered. Convenience is, of course, or ought to be, made a _sine quâ non_; yet it is not so much a positive merit in itself, as the want of it is a positive defect. Mere convenience is not an artistic quality: from that to beauty of plan,—to striking combinations, and studied effects, and varied play of arrangement, the distance is very great. A common-place plan is but a very dull uninteresting affair. It is no more than what any builder can accomplish; but a plan replete with imagination, piquant play, and well-imagined contrasts, is no every-day matter. PODIUM.—A continued pedestal; a dwarf pedestal wall; a closed parapet employed instead of an open balustrade. POLYSTYLE.—Having a number of columns. Where columns occur behind columns, as where a portico has inner columns, like that of the Royal Exchange, such portico may be termed _polystyle_. PORCH.—Any small portico considerably lower than the main structure to which it is attached may be so termed, in contradistinction from one carried up the height of the building, or as high as the principal cornice. PORTICO.—For the different plans and denominations of porticoes, see p. 69. PROFILE.—The outline of a series of mouldings, or of any other parts, as shown by a section through them.