Rome owed more to the last fifty years of its hated kings than to the two following centuries. From the royal period dates one of the most important monuments of vaulted construction, the Cloaca Maxima of Rome, built in the reign of Tarquinius Superbus, and probably under the direction of engineers from his native Etruria. To this gigantic work, admired even in the time of the magnificent Roman empire, is undoubtedly owing the preservation of the Eternal City, which it has secured from the swamping that has befallen its neighboring plains. Its quarried stones are still visible beneath the later brick arches in the vicinity of S. Giorgio in Velabro. (_Fig._ 266.) The building of drains naturally led to extensive works upon the banks of the river, which protected the thickly populated city; it was forgotten that, in earlier ages, it had often been necessary to traverse the Velabrum in boats, and that the spring freshets had extended a sheet of water between the Palatine and Capitoline hills.
[Illustration: Fig. 266.--Cloaca Maxima.]
All these structures were emphatically works of engineering; the building of walls, gateways, drains, and vaulted roofs presented nothing to elevate them into independent and artistic monuments of architecture. Among the Roman temples of this period only two appear to have been of importance for the history of art--the national shrine of Diana upon the Aventine, and the Temple of Jupiter Capitolinus; both built by the last three kings, Tarquinius Priscus, Servius Tullius, and Tarquinius Superbus. The first of these structures has been compared to the Artemesion at Ephesos, the national sanctuary of the Ionians; but it would be wrong to draw from this a conclusion in regard to the style of the Latin temple of the same goddess, which was most probably Tuscan, as that of the Temple of Jupiter is known to have been, from descriptions given by ancient writers as well as from the recent excavations of Jordan. According to Dionysios of Halicarnassos, the substructure of this latter building--eight hundred Roman feet in circumference--was only fifteen feet greater in length than in width; these dimensions agree well with the proportion of five to six given by Vitruvius for the temple architecture of the Etruscans. The cella of the Capitoline temple was divided into three ædiculæ, another peculiarity assigned by the Roman writer to the sacred edifices of Etruria; it had three ranges of columns, of six each, before the cella, which provided a portico equal in depth to half the entire length of the building. The ornamentation, which will be treated more fully in the section upon Roman sculpture, was wholly the work of the Etruscans. This race had, indeed, settled in Rome between the Capitol and the Palatine, where the name of Vicus Tuscus preserved, until late historical times, the memory of their settlement and of the considerable part taken by them in the peopling of ancient Rome. It is even stated by Pliny (xxxv. 12, 45, and 154) that, for seventeen years after the expulsion of the kings--namely, until the building of the Temple of Ceres upon the Circus--all the sanctuaries of Rome were Etruscan; that is to say, were not only built in the Tuscan style, which might more properly be called the ancient Italian, but were erected by Etruscan artificers, or, at least, under the direction of Etruscan artists.