CATARACTS, AND INUNDATIONS. 79 



Danube, he must have forgotten the Rhine, the Elbe, the Oder, 

 the Vistula, not to mention the Loire of France, the Tajo of Spam, 

 and other noble streams ! The numerous tributary rivers, from the 

 Alps and Apennines, bring down so much sand and gravel that the 

 bed of the Po has in modern times been considerably raised, so that 

 in many places banks of thirty feet in height are necessary to pre- 

 serve the country from inundation. Hence hydraulics have been 

 much studied in the north of Italy ; and the numerous canals of 

 irrigation delight and instruct the traveller. Perhaps by deepening 

 the chief estuary, and bed of the river, equal service might have 

 been rendered to commerce. In the middle ages maritime combats 

 took place on the Po, between Venice and some of the inland 

 powers. It is remarkable that, from Cremona to the sea, there is 

 no capital city founded o the main stream of the Po ; ad the c^se 

 was the same in ancient times; an exception to the supposition that 

 every river has some grand city near its estuary *. 



9. The Tiler. 



This stream immortalized in both prose and verse, and by far the 

 most considerable in the middle or south of Italy, is said to derive 

 its name from Tiberinus, an early Latin king, and direct descendant 

 of Oneus, by Lairnia, who was drowned in its waters in the course 

 of a battle which was fought on its banks. 



It rises near the source of the Arno, south east of St. Marino, 

 and passes by Perugia and Rome, to the Mediterranean, which it 

 joins after a course of about 150 miles. It is said to receive not 

 fewer than forty-two rivers or torrents, many of I hem celebrated in 

 Roman history ; as is the Rubicon, a diminutive stream, now the 

 Fitrmesino, which enters the Adriatic, about eight British miles to 

 the north of Rimini. 



In consequence of these numerous torrents it occasionally over- 

 flows its banks; and in an early period of the Roman empire, before 

 its embankment was made sufficiently powerful and lofty, these 



* To the N. of Ferrara the Po seems as broad as the "Rhine at Dusseldorf, 

 Stolberg, ii. 576 : but is probably not above half as deep. Dr. Smith, ii. 360, 

 compares the Po, near Ferrara, to the Maese at Rotterdam, and says it is 

 nearly as wide. That Maese is only a branch of the Rhine. 



