The Cogon, Fatallah and Konkure are all large rivers which descend from the plateaus through deep, narrow valleys in rapids and cataracts, and are only navigable for a few miles from their mouth.
The Uaupes is full of similar obstacles, some fifty rapids barring its navigation, although a long stretch of its upper course is said to be free from them, and to flow gently through a forested country.
Barred by reefs, and full of rapids and impetuous currents, it cannot become a commercial avenue.
The crowning point of his railway policy was the regulation of the Danube at the hitherto impassable Iron-Gates Rapids by the construction of canals, which opened up the eastern trade to Hungary and was an event of international importance.
NAUVOO, a city of Hancock county, Illinois, U.S.A., on the Mississippi river at the head of the lower rapids and about 50 m.
M., and which is full of rapids and navigable only for the smallest boats; (3) the Yuen-kiang, a large river, which has some of its head-waters in the province of Kwei-chow, and empties into the Tung-t'ing lake in the neighbourhood of Chang-te Fu; its basin has an area of 35,000 sq.
The eastern reaches of the Hari Rud river are frozen hard in the winter, rapids and all, and the people travel on it as on a road.
The region was once covered, with the exception of the higher summits, by the Laurentian glacier, whose erosion, while perhaps having little effect on the larger features of the country, has greatly modified it in detail, producing lakes and ponds, whose number is said to exceed 1300, and causing many falls and rapids in the streams. Among the larger lakes are the Upper and Lower Saranac, Big and Little Tupper, Schroon, Placid, Long, Raquette and Blue Mountain.
Deep; the small branches ramify indefinitely in typical insequent arrangement; the streams are nearly everywhere well graded; rapids are rare and lakes are unknown.
This is one of the most important fluvial systems of Brazil, but its economic value is impaired by the great waterfalls of Guayra, or Sete Quedas, and Uribu-punga, and by the rapids and waterfalls in the majority of its affluents near their junction with the main stream.