260 BASE OF THE SAHARA. 



sive motions, says Denham, in describing the manner in 

 ■which the child was forced from her and thrown on the 

 sand, where it was left to perish, while whips were applied 

 to her, lame and worn out as she was, to quicken her tot- 

 tering steps, were intensely affecting. After travelling 

 through a wooded and beautiful country, they, on February 

 17th, reached Kouka. This was to the travellers an im- 

 portant day, as they were now about to become acquainted 

 with a people who had never seen, or scarcely heard of an 

 European. 



In a journey which was undertaken to Mandara, the 

 whole country to Affagay was found to be alluvial. Den- 

 ham crossed part of a great range of mountains, named the 

 Mandara hills, at the most southern limit of this journey. 

 He says, " On all sides the apparently interminable chain 

 of hills closed upon our view in rugged magnificence and 

 gigantic grandeur, though not to be compared with the 

 higher Alps, the Apennines, or even the Sierra Morena, in 

 magnitude ; yet by none of these were they surpassed in 

 picturesque effect." This range of mountains was found 

 to contain granite, mica-slate, hornblende rock, and ores of 

 iron. There were observed on the southward lower ranges 

 of newer formation, consisting of conglomerated rocks 

 abounding in fossil oyster-shells. 



On what Formation does the Sand of the Desert rest ? — It 

 is a question with geologists, on what formation or forma- 

 tions does the sand of the Desert rest 1 We have not data 

 sufficient for a very satisfactory answer to this question. 

 Judging, however, from the details of travellers, we would 

 infer that the predominating formations are of the second- 

 ary class of rocks. The secondary formations met with are, 

 red and variegated sandstone, with gypsum and salt, and 

 white and graij sandstone sometimes disposed in fantastic 

 forms. The salt in some places is seen in thick beds, along 

 with red or variegated sandstones. Limestones of various 

 descriptions, that appear to belong to the Jura limestone 

 formation, are nvet with. Besides those already enume- 

 rated, there occur other limestones, clays, and gypsums, 

 Delonging to the tertiary class, from which salt springs 

 issue. But not only these softer rocks appeared rising 

 through the sands of the Desert ; also harder rocks, aa 

 greenstone, amygdaloid, and granite, in some places project. 



