The Reno is the most erratic, the most dangerous of all these Apennine rivers. The bed of débris deposited by it in the plain measures 20 miles across from east to west. Its volume varies between 35 and 49,500 cubic feet a second, according to the season, and its bed is in places no less than 30 feet above the adjoining country. The destruction of the forests has augmented the danger of its inundations. The engineers, puzzled by its irregular floods, have proposed the most {209} opposite plans for subduing this terrible scourge. The river has been turned into the Po; then eastward, direct into the sea. Recently it has been proposed to divert it to the lagoons of Comacchio. But all these diversions are attended with disadvantages, and whilst the inhabitants of one district congratulate themselves upon having got rid of so troublesome a neighbour, those of another complain of its inundations, see their fisheries destroyed, and their navigation interfered with. [Illustration: Fig. 68.—COLONIES OF THE ROMAN VETERANS. Scale 1 : 356,000.] Lombardini, the famous hydraulic engineer, has shown how we may discover the places to which the soil of the lowlands of Emilia has been conveyed by the torrents, and trace the ancient shores of the lagoon of Padua, now converted into dry land. A traveller following the Emilian causeway from Cesena to Bologna can hardly help noticing the quadrangular fields on his right, all of them of the same size. Looked at from the spurs of the Apennines, the plain resembles a huge draught-board, the squares of which are covered alternately with verdure and ripening crops. We learn from the topographical maps that these fields are exactly of the same size, and there can be no doubt that we have here before us the fields which, according to Livy, were taken from the Gauls and distributed amongst Roman military settlers. A sinuous line marks, in the direction of the Po, the shore of an ancient lake. The rectangular fields, laid out by the cadastral surveyors of ancient Rome, cease there, and we find ourselves again amidst the usual labyrinth of ditches and tortuous roads. This lake has been filled up long ago by the débris brought down by the torrents. {210} The Po, proportionately to the area it drains and its length, has undergone fewer changes than either the Piave or the Reno, but looking to the populous cities which line its banks, and to the fertility of its fields, the least of these is of some importance.