It may be interesting to our readers to learn that these movements have been checked in modern times. By a system of artificial embankment the waters of the river are now confined within definite and narrow limits: thus the velocity of the current is increased and a very considerable portion of the sediment is carried on to the sea. Nevertheless, much is still deposited in the bed of the river, which is, in consequence, raised higher and higher each successive year. Hence it has become necessary, in order to prevent inundations, to add every season to the height of the embankments, so that the river now presents the appearance of an enormous aqueduct, of which some idea may be formed from the fact that, in the neighborhood of Ferrara, the surface of the stream is higher than the roofs of the houses. This system of embankment is carried on very extensively in Northern Italy to check the overflowing of rivers, and to prevent them from changing their courses. It is as old as the time of Dante, who tells us that the inhabitants of Padua erected barriers along the Brenta when the snows began to melt and the season of the floods was approaching, “Per difender lor ville e lor castelli, Anzi che Chiarentana il caldo senta.” _Inferno_, Canto xv. As a river sometimes fills up its own channel, so too may it fill up a lake through which it flows, and convert it likewise into a great Alluvial Plain. Thus it is said several extensive lakes have been transformed into dry land in modern times near Parma, Piacenza, and Cremona. Elsewhere the process may be seen in actual operation. The Rhone when it enters the lake of Geneva is a turbid discolored stream; the natural consequence of the immense quantity of earthy sediment with which it is charged. But as it slowly moves along, the sediment falls to the bottom, and when, at length, “by Leman’s waters washed,” it emerges at the town of Geneva, and shoots beneath the magnificent bridge that joins the opposite shores, it has already assumed that beautiful azure blue which travellers love to gaze on, and poets love to sing. The sediment left behind goes to form a great alluvial tract which is slowly but steadily advancing into the lake. An ancient town called Port Vallais, which, eight centuries ago, stood at the water’s edge, is now a mile and a half inland. And if the world were to last long enough, and the natural agents at present in operation were to remain unchanged, the time would come, we can scarcely doubt, when the whole lake of Geneva would have been converted into an Alluvial Plain of vast extent and inexhaustible fertility.