assault, there was nothing in its position which could be looked upon as favourable; but when by valour and labour these districts became its own, there succeeded a tide of prosperity surpassing the advantages of every other place. Thus, notwithstanding the prodigious increase of the city, there has been plenty of food, and also of wood and stone for ceaseless building, rendered necessary by the falling down of houses, and on account of conflagrations, and of the sales, which seem never to cease. These sales are a kind of voluntary falling down of houses, each owner knocking down and rebuilding one part or another according to his individual taste. For these purposes the numerous quarries, the forests, and the rivers which convey the materials, offer wonderful facilities. Of these rivers, the first is the Teverone,[1841] which flows from Alba, a city of the Latins near to the country of the Marsi, and from thence through the plain below this [city], till it unites with the Tiber. After this come the Nera[1842] and the Timia,[1843] which passing through Ombrica fall into the Tiber, and the Chiana,[1844] which flows through Tyrrhenia and the territory of Clusium.[1845] Augustus Cæsar endeavoured to avert from the city damages of the kind alluded to, and instituted a company of freedmen, who should be ready to lend their assistance in cases of conflagration;[1846] whilst, as a preventive against the falling of houses, he decreed that all new buildings should not be carried so high as formerly, and that those erected along the public ways should not exceed seventy feet in height.[1847] But these improvements must have ceased only for the facilities afforded by the quarries, the forests, and the ease of transport.