The river falls in cataracts and rapids over Boo ft.
On some of these channels deep gorges were eroded heading in temporary cataracts which exceeded Niagara in height but not in breadth; the pools excavated by the plunging waters at the head of the gorges are now occupied by little lakes.
Between the mouths of the Hartebeest and Molopo, in 28° 35' S., 20° 20' E., are the great waterfalls of the Orange, where in a series of cataracts and cascades the river drops 400 ft.
Away, and from cataracts in Cottonwood canyon and other canyons.
Through these, the river carves its channel, broken into cataracts and rapids, or cachoeiras, as they are called throughout Brazil.
San Antonio is the first of a formidable series of cataracts and rapids, nineteen in number, which, for a river distance of 263 m., obstruct the upper course of the Madeira until the last rapid called Guajara Merim (or Small Pebble), is reached, a little below the union of the Guapore with the Mamore.
But just before reaching the Uaupes there is a long series of reefs, over which it violently flows in cataracts, rapids and whirlpools.
The rivers of Africa are generally obstructed either by bars at their mouths or by cataracts at no great distance up-stream.
The rivers of the narrow mountainous peninsulas form many rapids and cataracts; as the Tondano, draining the lake of the same name to the north-west coast of Minahassa at Menado; the Rano-i-Apo, flowing over the plateau of Mongondo to the Gulf of Amurang; the Poigar, issuing from a little-known lake of that plateau; the Lombagin, traversing narrow canons; and the river of Boni, which has its outfall in the plain of Gorontalo, near the mouth of the Bolango or Tapa, the latter connected by a canal with the Lake of Limbotto.
Evans, " The Rocks of the Cataracts of the River Madeira and the adjoining Portions of the Beni and Mamore," Quart.
Charged with all this matter, the Semliki, as it emerges from the region of forest and cataracts (in which, often closely confined by its mountain barriers, the stream is deep and rapid), becomes sluggish, its slope flattens out, and its waters, unable to carry their burden, deposit much of it upon the land.
In this section of the river there occurs a continuous series of slight falls and rapids, including all the historical "six cataracts," beginning below Khartum and terminating at Philae.
It was owing to their incessant raids that Diocletian withdrew the Roman garrisons above the cataracts, and called in the warlike Nobatae to protect the Egyptian frontier from their attacks.
This alpine region sends out numerous rivers in a southerly direction, which, forcing their passage through narrow defiles, and precipitated in cataracts over the precipices, eventually pour themselves into the Brahmaputra.
Butler, Campaign of the Cataracts (London, 1887); Count A.
With cataracts, which obstructed navigation to all but small boats, except during the period of high water.
The "cascades" are wonderful formations like foaming cataracts caught in mid-air and transformed into milk-white or amber alabaster.
Below Stora Lule lake the river forms the Harsprang (hare's leap; Njuommelsaska of the Lapps), the largest and one of the finest cataracts in Europe.
The lower Arinos, the Alto Tapajos and the Tapajos to the last rapid, the Maranhao Grande, is a continuous series of formidable cataracts and rapids; but from the Maranhao Grande to its mouth, about 188 m., the river can be navigated by large vessels.
These rivers are navigable for short distances, but in general rapids or cataracts mark their middle courses.
Above Nyangwe, on the main stream, another railway is built around the next series of cataracts, thus opening to through communication the upper Lualaba.
Just below this the mountains close in on either side of the Maranon, forming narrows or pongos for a length of 35 m., where, besides numerous whirlpools, there are no less than thirty-five formidable rapids, the series concluding with three cataracts just before reaching the river Imasa or Chunchunga, near the mouth of which La Condamine embarked in the t8th century to descend the Amazon.
The inferior zone of the river, as far up as the first fall, the Porteira, has but little broken water and is low and swampy; but above the long series of cataracts and rapids the character and aspect of the valley completely change, and the climate is much better.
These two rivers have emptied a large system of lakes, which in pre-Glacial times occupied the eastern zone, thus forming a region suitable for colonization in the broad valleys and hollows, where the rivers, as in the case with those in the north, cut through the Andes by narrow gaps, forming cataracts and rapids between the snowy peaks.
If, on the one hand, huge stones are transported hundreds of miles from sea-shore or river-bed where, in the lapse of long centuries, waves and cataracts have hammered them into strange shapes, and if the harmonizing of their various colors and the adjustment of their forms to environment are studied with profound subtlety, so the training and tending of the trees and shrubs that keep them company require much taste and much toil.
Deepand Assuan (First Cataract), the course of the river is interrupted by outcrops of granites and other crystalline rocks, which have been uncovered by the, erosion of the overlying sandstone, and to-day form the mass of islands, with numerous small rapids, which are described not very accurately as cataracts; no good evidence exists in support of the view that they are the remains of a massive barrier, broken down and carried away by some sudden convulsion.
Many of the Egyptian rocks in the desert areas and at the cataracts are coated with a highly polished film, of almost microscopic thinness, consisting chiefly of oxides of iron and manganese with salts of magnesia and lime.
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 lower Congo and coast regions are occupied by the Ba-Kongo (otherwise Ba-Fiot), a division including the Mushi-Kongo, found chiefly in the Congo division of Angola, and the Basundi, who live on both banks of the river in the cataracts districts, the Kabinda and the Mayumbe - the two last named dwelling in the coast districts and foot-hills immediately north of the mouth of the Congo.
In 2 m.., through a sandstone chasm, in a series of cataracts, some of them having an 80 ft.