The usual plan of a Roman house consisted of the _Ostium_ or entrance, sometimes called the _Vestibule_, which opened into the _Atrium_, which was a large room or court partly roofed over, with an opening in the centre called the _Conpluvium_, under which was the _Impluvium_, or cistern of water, placed below the level of the ground. Small chambers surrounded the _Atrium_, and at the further end was the _Tablinum_ or private room, frequently leading to the _Peristylium_ or private part of the house, an open court, with a colonnade surrounding a marble fountain, with flowers, shrubs and trees, forming a _Viridarium_. Surrounding the _Peristylium_ were private rooms, one of which was the _Triclinium_ or dining room. From the _Peristylium_, _fauces_ or passages led to the _Porticus_, a colonnade which overlooked the garden. [Illustration: ROMAN ORNAMENT. Plate 8 ] ROMAN ORNAMENT. Rome, founded by Romulus, B.C. 783, became by successive wars and conquests the mistress of the world, absorbing the arts and the architecture of the Etruscans B.C. 567, the Samnites B.C. 340, and of Corinth and Carthage B.C. 146. From these varied sources arose the style termed Roman, assimilating and adopting the column and the horizontal entablature of the Greeks; the arch, the vault, the mural paintings and the decorative use of bronze and the terra-cotta of the Etruscans, with the sculpture, ornament, mosaics and coinage of the Greeks and Carthaginians. These varied arts were assimilated and perfected by the Romans during the period B.C. 100 to 337 A.D. Roman ornament is the continuity of the Greek and Etruscan styles, consisting of the anthemion, the acanthus and the scroll; the Romans using these forms with greater exuberance and elaboration, together with bold and vigorous carving, yet lacking the simplicity, refinement and graceful contour of the Greek and Etruscan forms. [Illustration] [Illustration] Roman ornament consists largely of continuous spiral lines clothed with cups and sheaths of acanthus foliage, the various spirals terminating in a rosette. These main spirals are frequently interwoven with fine curved or spiral lines, clothed with acanthus or other foliation, such as the vine, olive and ivy. Birds and reptiles and cupids, and the chimera or griffin (fig. 1) are often interspersed with the ornament, thus giving that largeness of mass and contrast of form which is so characteristic of Roman art. The Thermæ, or baths and public buildings, displayed fine decorative ceilings, having deep sunk panels called Lacunaria; or coffers, square, hexagonal or octagonal in form, with a centre rosette in high relief and the border mouldings of the coffers being enriched with the egg and dart or the water leaf. These exhibit an effective treatment of moulded surfaces. The ceilings of the tombs and palaces were in many cases ornamented [Illustration: ROMAN ORNAMENT. Plate 9. ]