THE SOIL MAKERS 



give up their finest dust, and send real soil downward to a 

 lower level. It is beyond our power to estimate the enor- 

 mous quantity of soil that is moved during a single year. 

 A single illustration will show how great this quantity is: 

 The Mississippi River as it pours into the Gulf of Mexico 

 each year deposits soil sufficient in quantity to cover an 

 area of 100 square miles nearly three feet in depth. Add 

 to this the outpourings of all river systems and you have 

 land areas made each year that equal many a state in size. 

 Whenever a river outflows its banks it leaves deposited 

 on the submerged territory tons and tons of mud and 

 this mud is valuable soil often as much as an inch in 

 thickness. 



In all mountainous regions we have the results of the 

 wearing power of water. Huge canons, hundreds of feet 

 deep the Colorado Canon is 6,000 feet in depth mark 

 the track of the leaps and pourings of water from the 

 mountain summits. When considered in the aggregate, 

 the amount of soil made by water-washing of our thou- 



A FIELD OK CORN CARRIED AWAY BY A RAGING FLOOD 



