There is no doubt that many of the earliest works of the Romans were executed under the direction of Etruscan architects. Among these was the great Cloaca Maxima, or principal drain of ancient Rome. This was a wonderful achievement; it is probable that the oldest arch in Europe is that of this sewer, and the fact of its still remaining proves how well it must have been built in order to last so long (Fig. 59). [Illustration: FIG. 59.--ARCH OF CLOACA MAXIMA. _Rome._] ROME. The early works of Rome, which were largely executed by the Etruscans, were principally those useful, semi-architectural objects necessary in the making of a city, such as aqueducts and bridges. These belong quite as much to civil engineering as to architecture, and we shall not speak of them. In studying Roman architecture one is surprised at the number of uses to which it was applied, for not only do the temples, tombs, theatres, and monuments such as we have found in other countries exist in Rome, but there are also basilicas, baths, palaces, triumphal arches, pillars of victory, fountains, and various other objects suited to the wants of a great people. [Illustration: FIG. 60.--COMPOSITE ORDER, FROM THE ARCH OF SEPTIMIUS SEVERUS. _Rome._] No truly pure, national order of architecture existed at Rome. The union of the arch of the Etruscans with the columns of the Greeks enabled the Romans to change the forms of their edifices and to produce a great variety in them. They employed the Doric, Ionic, and Corinthian orders, but they rarely used one of these alone; they united them in endless combinations, and introduced a capital of the order which is called the Composite (Fig. 60). It consists of the lower part of the Corinthian and the upper part of the Ionic capital; this was very rich in ornament, but the line where the two orders were joined was always a defect, and it never came into general favor. The Romans also introduced what is called the Tuscan order, which is usually mentioned with the Doric, Ionic, Corinthian, and Composite, as being one of the five classic orders of architecture, although it is really little more than a variety of the Doric, as the Composite is of the Corinthian order. It differed from the Doric in having a base, while its frieze was simple and unadorned, the cornice also being very plain. The shaft of the Tuscan column was never fluted. [Illustration: FIG. 61.--DORIC ARCADE.] The Romans also used an arcade which was a combination of Greek and Etruscan art, like this cut (Fig. 61); thus showing a power of adapting forms which already existed in new combinations and for new purposes, rather than an originative genius.