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 with 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 frequents 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 
