ROCK DESTRUCTION IN ARID REGIONS 87 



winds, blowing steadily in one direction, carry great quantities of 

 dust and fine sand with them, sometimes directly into the sea or 

 other bodies of water, sometimes into rivers, or again to moister 

 regions, where it comes under the influence of the rain. 



Slowly as they work, the wind and temperature changes prevent 

 any complete stagnation in the circulation of material, and thanks 

 to them, the processes of disintegration of rock and transporta- 

 tion of soil are kept up even in the dryest deserts. 



