THE WATER IN THE SOIL 



15 



used, so that each cylinder may receive the same amount of 

 water. Record the time when you begin, and see how 

 long it takes each soil to take up the water, how long it 

 takes the water to reach the bottom of each chimney, or 

 cylinder, after being added at the top, and how much 

 water passes through each soil in a given time. The 

 amount of water that passes through each soil may be 

 collected in glasses below the chimneys and measured. 

 A table like this will help you to keep an accurate record 

 in your notebook : 



Conclusion. — There are millions of acres of sandy 

 hills in the United States and there are scarcely any gullies 

 washed in them. Clay hills are always full of washouts. 

 How long did it take the clay to take up the cup of water? 

 Why do the clay hills wash so much worse than those 

 made up largely of sand ? 



EXERCISE 5 



Object. — To determine the relation of the amount of 

 humus in the soil to the amount of water it will take up and 

 hold. 



Procedure. — Fill a can with soil from the middle of a 

 well traveled road ; another with soil from an old fence 

 row near by, so that the two soils will be as nearly alike 

 as possible except for the amount of organic matter which 



