[21] Byron. [22] This does not occur in the Pompeian houses. [23] Marked _a_, _a_, on the plans. [24] Vitruvius, however, seems to use the terms _atrium_ and _cavædium_ as quite synonymous. [25] Marked respectively _c_, and _f_, _f_, on the plan of the House of Pansa. [26] Marked _b_, _b_, on the plans. [27] At the Crystal Palace can be seen an interesting reproduction of a Pompeian house, which was designed by the late Sir Digby Wyatt. It gives a very faithful reproduction of the arrangement and the size of an average Pompeian house; and though every part is rather more fully covered with decoration than was usual in the originals, the decorations of each room faithfully reproduce the treatment of some original in Pompeii or Herculaneum. [Illustration: FIG. 144.--CARVING FROM THE FORUM OF NERVA, ROME.] CHAPTER X. ROMAN ARCHITECTURE. _Analysis._ _The Plan_ (_or floor-disposition_).--The plans of Roman buildings are striking from their variety and the vast extent which in some cases they display, as well as from a certain freedom, mastery, and facility of handling which are not seen in earlier work. Their variety is partly due to the very various purposes which the buildings of the Romans were designed to serve: these comprised all to which Greek buildings had been appropriated, and many others, the product of the complex and luxurious civilisation of the Empire. But independent of this circumstance, the employment of such various forms in the plans of buildings as the ellipse, the circle, and the octagon, and their facile use, seem to denote a people who could build rapidly, and who looked carefully to the general masses and outlines of what they built, however carelessly they handled the minute details. The freedom with which these new forms were employed arises partly also from the fact that the Romans were in possession of a system of construction which rendered them practically independent of most of the restrictions which had fettered the genius of the Egyptians, Assyrians, and Greeks. Their vaulted roofs could be supported by a comparatively small number of piers of great solidity, placed far apart; and accordingly in the great halls of the Thermæ and elsewhere we find planning in which, a few stable points of support being secured, the outline of the spaces between them is varied at the pleasure of the architect in the most picturesque and pleasing manner. The actual floor received a good deal of attention from the Romans. It was generally covered with tesselated pavement, often with mosaic, and its treatment entered into the scheme of the design for most interiors. _The Walls._