RIVER EMBANKMENTS. 509 
that the system of longitudinal dikes is fundamentally wrong, 
and it has been argued that if the Po, the Adige, and the Bren- 
ta had been left unconfined, as the Nile formerly was, and 
allowed to spread their muddy waters at will, according to the 
laws of nature, the sediment they have carried to the coast 
would have been chiefly distributed over the plains of Lombar- 
dy. Their banks, it is supposed, would have risen as fast as 
their beds, the coast-line would not have been extended so far 
into the Adriatic, and, the current of the streams being conse- 
quently shorter, the inclination of theirchannel and the rapidity 
of their flow would not have been so greatly diminished. Had 
retired to its ordinary level, because the dike, which had been built to keep 
the water out, now kept it 7. 
According to Arthur Young, on the lower Po, where the surface of the 
river at high water has been elevated considerably above the level of the ad- 
jacent fields by diking, the peasants in his time frequently endeavored to secure 
their grounds against threatened devastation through the bursting of the 
dikes, by crossing the river when the danger beeame imminent and opening 
a cut inthe opposite bank, thus saving their own property by flooding their 
neighbors’. He adds, that at high water the navigation of the river was abso- 
lutely interdicted, except to mail and passenger boats, and that the guards 
fired upon all others; the object of the prohibition being to prevent the 
peasants from resorting to this measure of self-defence.—TZvravels in Italy - 
and Spain, Nov. 7, 1789. 
In a flood of the Po in 1839, a breach of the embankment took place at 
Bonizzo. The water poured through and inundated 116,000 acres, or 181 
square miles, of the plain to the depth of from twenty to twenty-three feet, in 
the lower parts. The inundation of May, 1872, a great breach occurred in the 
dike near Ferrara, and 170,000 acres of cultivated Jand were overflowed, and a 
population of 30,000 souls driven from their homes. In the flood of October 
in the same year, in consequence of a breach of the dike at Revere, 250,000 
acres of cultivated soil were overflowed, and 60,000 persons were made 
homeless. The dikes were seriously injured at more than forty points. 
See page 279, ante. In the flood of 1856, the Loire made seventy-three breaches 
in its dikes, and thus, instead of a comparatively gradual rise and gentle 
expansion of its waters, it created seventy-three impetuous torrents, which 
inflicted infinitely greater mischief than a simply natural overflow would 
have done. The dikes or levées of the Mississippi, being of more recent con- 
struction than those of the Po, are not yet well consolidated and fortified, and 
for this reason crevasses which occasion destructive inundations are of very 
frequent occurrence, 
