8. These advantages accrued to the city from the nature of the country; but the foresight of the Romans added others [CAS. 235] besides. The Grecian cities are thought to have flourished mainly on account of the felicitous choice made by their founders, in regard to the beauty and strength of their sites, their proximity to some port, and the fineness of the country. But the Roman prudence was more particularly employed on matters which had received but little attention from the Greeks, such as paving their roads, constructing aqueducts, and sewers, to convey the sewage of the city into the Tiber. In fact, they have paved the roads, cut through hills, and filled up valleys, so that the merchandise may be conveyed by carriage from the ports. The sewers, arched over with hewn stones, are large enough in some parts for waggons loaded with hay to pass through; while so plentiful is the supply of water from the aqueducts, that rivers may be said to flow through the city and the sewers, and almost every house is furnished with water-pipes and copious fountains. To effect which Marcus Agrippa directed his special attention; he likewise bestowed upon the city numerous ornaments. We may remark, that the ancients, occupied with greater and more necessary concerns, paid but little attention to the beautifying of Rome. But their successors, and especially those of our own day, without neglecting these things, have at the same time embellished the city with numerous and splendid objects. Pompey, divus Cæsar, and Augustus, with his children, friends, wife, and sister, have surpassed all others in their zeal and munificence in these decorations. The greater number of these may be seen in the Campus Martius, which to the beauties of nature adds those of art. The size of the plain is marvellous, permitting chariot-races and other feats of horsemanship without impediment, and multitudes to exercise themselves at ball,[1848] in the circus[1849] and the palæstra. The structures which surround it, the turf covered with herbage all the year round, the summits of the hills beyond the Tiber, extending from its banks with panoramic effect, present a spectacle which the eye abandons with regret. Near to this plain is another surrounded with columns, sacred groves, three theatres, an amphitheatre, and superb temples in close contiguity to each other; and so magnificent, that it would seem idle to describe the rest of the city after it. For this cause the Romans, esteeming it as the most sacred place, have there erected funeral monuments to the most illustrious persons of either sex. The most remarkable of these is that designated as the Mausoleum,[1850] which consists of a mound of earth raised upon a high foundation of white marble, situated near the river, and covered to the top with ever-green shrubs. Upon the summit is a bronze statue of Augustus Cæsar, and beneath the mound are the ashes[1851] of himself, his relatives, and friends.