374 Messrs. Playfair and Letourneux on the 



The watershed of the Tell is as regular as in other coun- 

 tries ; and its streams all reach the sea. Although the general 

 direction of the mountain-range is from east to west, the con- 

 figuration of the ground is very irregular ; and confused moun- 

 tain masses frequently occur, throwing out lateral spurs or 

 buttresses, which in many instances plunge al»ruj)tly into the 

 sea. This has caused numerous basins, often narrow and 

 tortuous, and has been the means of confining the watercourses 

 between the perpendicular walls of narrow gorges. 



The sources of the principal streams are situated high up, 

 either on the southern border of the Tell, on the first terraces 

 of the High Plateaux*, or on the flanks of the great isolated 

 mountain masses!. 



In spite of the meanderings often necessitated by the nature 

 of the ground, the streams of the Tell are generally short : 

 the Chelif alone has a length of 244 miles ; but a great part of 

 its course is owing to exceptional causes in the regions of the 

 High Plateaux. It follows that the rivers and streams flowing 

 over a steep incline are, in the rainy season or after a storm, 

 foaming torrents, canying down in their troubled waters huge 

 masses of stone broken from their beds and trees torn from 

 their banks J. During summer, on the other hand, the beds 

 of these rivers are entirely dry in the mountains and in the 

 plains, where their banks are sometimes half a mile distant 

 from each other, inclosing a sandy bed invaded by vegetation ; 

 all that remains is a tiny stream in the middle, and here and 

 there a few pools of stagnant water. 



The most considerable rivers in Algeria are, the Mafrag, 

 the Seybouse, the Oued-el-Kebir, the Makta, &c., which 

 during flood-time 'discolour the water for several miles at sea, 

 and have not the strength in summer to force themselves a 

 passage through the banks of sand accumulated in their 

 estuaries by the currents along the coast. 



Alluvial plains of any considerable extent are rare in Al- 

 geria; they do not form, as elsewhere, in the estuary of a 

 great river. Parallel to the sea they stretch between the foot 

 of the mountains and the isolated groups of hills, once proba- 

 bly islands, such as those at La Calle, to the north of the plain 

 of Tarf, El-Edough in the plain of Bone, the Sahel at Algiers, 



history. DeCandoUe affirms the existence of the ancient communication 

 between Numidia and the Italian islands. 



* From 2500 to 3000 feet above the sea. 



t Jurj lira, 7385 feet ; Ouarensis, 6425 feet ; Bators, 6336 feet. 



X Freshets in the Seybouse have frequently been known to carry down 

 several hundred trees to the sea, and even wild boar, surprised by the 

 inundation and unable to contend ao^ainst the strenffth of the current. 



