GRAPHIC DESCRIPTION OF AFRICA. 249 



Camp, in his charming work on the Nile, describes in the fol- 

 lowing terms one of these desert tempests. It comes towards one, 

 he says, growing, spreading, and advancing as if on wheels. Its 

 overhanging summit is of a brick color, its base deep red and almost 

 black. In proportion as it approaches it drives before it burning 

 effluvia, like the breath of a lime-kiln. Before it reaches us we are 

 covered v\'ith its shadow. The sound it makes is like that of a wind 

 passing through a pine-forest. So soon as we are in the midst of 

 this hurricane the camels halt, turn their backs, throw themselves 

 down, and lay their heads upon the sand. After the cloud of dust 

 comes a rain of imperceptible stones, violently hurled about by the 

 wind, and which, if it lasted long, would quickly flay the skin from 

 those parts of the body unprotected by the clothes. This lasted five 

 or six minutes, and was frightful. Then the sky became clear 

 again, and gave the same feeling of sudden change to the eye as a 

 light suddenly brought into a dark place. 



FUNNEL-SHAPED STORM PILLARS. 



Whirlwinds are generally preceded by a sultry, oppressive air; 

 sometimes by absolute calm ; but the state of the wind never appears 

 clearly connected with the phenomena. The storm pillars vary 

 greatly in form, the sand columns being generally funnel-shaped, 

 and the water-spouts like a pipe surrounded at the base by whirling 

 vapors and foaming water. The height and diameter are also 

 variable; some of the highest have been estimated at 6,000 feet. In 

 many cases the damage caused by the water is of such a kind as to 

 show that there has been an influx of air from every side toward the 

 base of the column. 



But hurricanes, cyclones, and all the rush and roar of the 

 elements, are not more wonderful than the curious forms of animal 

 and insect life abounding in the Dark Continent. 



The reptile tribe is represented here by some of its most distin- 

 guished members. The monitor-lizard crawls along the river banks ; 

 the mountain-monitor frecjuents the desert; a beautiful turtle lives 

 in the Nile. Along the furrows and trenches, nimble bright-colored 

 lizards bask in the sun, and the slippery skink burrows in the wall 



