48 ALGERIA 



was originally a deep depression between the Tell and the 

 Sahara Atlas, which in the course of thousands of years was 

 gradually filled up with the alluvial deposits of mountain- 

 torrents and thus converted into a great and monotonous 

 undulating plain 701 to 1005.7 metres (2300 to 3300 feet) above 

 the sea level. The saline and gypseous is very sterile and 

 only at a few places is adapted for the culture of grain, but has 

 proved suitable for sheep-grazing. In the depressions of the 

 steppe lie a number of extensive shoots or salt lakes, which 

 in summer are dry and recognizable only by their dazzling 

 snow-white incrustation. 



"III. The Sahara Atlas (Atlas Saharien) forms the great 

 barrier between Algeria and the desert. It is a ' region of 

 grand and wildly fissured gorges, partly caused by erosion 

 in the pluvial period, of valleys worn by torrents, of lofty 

 plains converted into mountains, and of marine basins now 

 filled up.' (Theob. Fischer.) The chief heights are the 

 Montagnes des Ksour, 2134.7 metres (7004 feet), a pro- 

 longation of the much higher Morocco Atlas; Jebel Amour, 

 1971 metres (6467 feet); the Monts des Ouled-Nail, 1613 

 metres (5295 feet); and, beyond the depression of the Monts 

 du Zab, 1311.4 metres (4304 feet); the Aures Mountains, 

 2326.7 metres (7634 feet), which are wooded in their north 

 half. . . . 



"IV. The Sahara, which belongs to the Territoires du Sud 

 or de Commandement, governed by the military 'Bureaux 

 Arabes,' consists of the Bassin du Gourara or Bassin de 

 1'Oued Saoura on the west, a plateau 100.6 to 792.4 metres 

 (330 to 2600 feet) above the sea, and of the Bassin du Melrir, 

 named after the Chott Melrir, on the east, lying partly 

 below the sea level." 



Climate. The climate 2 is characterized by two distinct 

 seasons, 3 one wet and one dry, a peculiarity due largely to the 

 nature of the winds. The prevailing winds during the rainy 

 winter season come from the northwest and north, while dur- 

 ing the summer east winds are prevalent. Purely local winds 

 due to topography or environment, proximity to the sea, moun- 



2 Les Forets de TAlg^rie par H. L. Le*febvre, 1900, pp. 56-98. 



3 It is of interest that Gsell in Le climat de 1'Afrique du nord dans Tantiquite drew 

 the conclusions that, broadly speaking, the climate of North Africa had not changed 

 to any degree since the Roman occupation, notwithstanding the deforestation. 

 1 I luntington, in the Quarterly Journal of Economics, Vol. XXXI, February 1917, 

 p. 173, argues that there have been climatic pulsations. 



